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[目的]分析重庆市土地利用时空演变规律,探究土地利用转型及景观格局响应的演变特征与城镇化的关系,为重庆市“三生”土地规划与城镇化可持续发展提供数据支持。[方法]基于“三生空间”功能分类的视角构建用地分类标准,利用2000,2010,2020年土地遥感影像和夜间灯光数据,采用转移矩阵、相关性分析及回归分析法进行分析。[结果]①2000—2020年重庆市生产、生态空间总体减少,生活空间持续扩张。2000—2010年,生产、生态空间减少191.87,252.95km~2,生活空间增大446.03km~2;2010—2020年,生产空间面积减少13.76km~2,生态空间减少324.05km~2,生活空间增大314.87km~2。②重庆市生产功能向生活功能转化较为明显。随着城镇化加强,生态空间转向生产空间显著,功能转变明显聚集于重庆市中心区域。③重庆市空间景观破碎度减小,景观复杂度逐渐提高,林草水生态空间占据主导优势。 ④2000—2010,2010—2020年土地利用面积变化对夜间灯光值的影响存在差异;2000年,城镇生活空间、农村生活空间变化对夜间灯光变化影响起主导作用,而2020年工业生产空间、城镇生活空间变化对夜间灯光变化影响较强。[结论]重庆市各类空间发生相互转换,利用不同“三生”空间类型变化和城镇化的关系,推动土地规划与城镇化协调发展。
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[Objective]The spatial and temporal evolution of land use in Chongqing City were analyzed,and the relationship between the evolution characteristics of land use transformation and landscape pattern response and urbanization was explored in order to provide data support for ecological-production-living spaces land planning and sustainable development of urbanization in Chongqing City.[Methods]A land use classification criteria was constructed based on the perspective of the functional classification of ecologicalproductional- living spaces;utilizing land remote sensing images and nighttime lighting data in 2000,2010, and 2020;and adopting the transfer matrix,correlation analysis,and regression analysis methods.[Results] ① From 2000to 2020,the productional and ecological space of Chongqing City generally decreased,and the living space continued to expand.From 2000to 2010,the productional and ecological space decreased by 191.87km~2 and 252.95km~2,respectively,and the living space increased by 446.03km~2.From 2010to 2020, the productional space decreased by 13.76km~2,ecological space decreased by 324.05km~2,and living space increased by 314.87km~2.② The shift of productional functions to living functions was more obvious in Chongqing City.As urbanization intensified,ecological space shifted significantly to productional space,and the shift in function was obviously gathered in the central region of Chongqing City.③ The spatial landscape fragmentation of Chongqing City decreased,the landscape complexity gradually increased,and the forest, grass,and water ecological space dominated.④ There were differences in the influence of land use area changes on nighttime light in 2000—2010and in 2010—2020.In 2000,changes in urban living space and rural living space played a dominant role in influencing changes in nighttime light,while changes in industrial production space and urban living space in 2020had a stronger influence on changes in nighttime light. [Conclusion]Various types of space in Chongqing City have been transformed into each other,and the relationship between changes in different ecological-productional-living spaces types and urbanization has been utilized to promote the coordinated development of land planning and urbanization.
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[目的]土地利用及其对陆地生态系统的影响是当前全球变化研究的重要内容。科学分析土地利用变化对植被覆盖度的影响,促进社会经济与生态环境质量的协调发展及地区经济的平衡发展,为政府部门对区域生态保护和恢复管理提供借鉴和参考。[方法]以湖北省为研究对象,利用2000,2020年2期Landsat遥感影像、土地利用遥感数据,利用遥感数据的空间处理、像元二分模型、土地利用转移矩阵等方法,分析研究湖北省植被覆盖的时空变化、土地利用类型变化特征及其对植被覆盖度的影响。[结果] ①2000—2020年,湖北省耕地、草地和未利用地面积减少,水域以及建设用地面积增加,林地面积基本保持不变,其面积大小顺序为:林地>耕地>水域>建设用地>草地>未利用地。②湖北省植被覆盖度平均值上升了6.50%。林地、耕地、草地和未利用地的平均植被覆盖度均有所增加,建设用地的平均植被覆盖度有所降低。③湖北省植被覆盖度总体呈现增加的趋势。植被覆盖度增大的区域主要集中在湖北省的西部和东南部地区,局部地区也存在植被退化的区域,主要集中在湖北省中南部及襄阳北方部分区域。④不同土地利用类型FVC转移过程中,耕地较高植被覆盖与高植被覆盖之间的转移过程最为剧烈,林地不同等级植被覆盖的转移量占转移总量的47.87%,草地不同水平植被覆盖度的转移量占转移总量比例较小,仅为3.40%。[结论]2000—2020年湖北省土地利用变化较大,不同土地利用类型的植被覆盖度相互转移,尤其是林地、耕地及草地的平均植被覆盖度均有所增加,使得湖北省近20a来整体植被覆盖度呈现出上升趋势。
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[Objective]The impacts of land use on terrestrial ecosystems are important for current global change research.The impacts of land use change on fractional vegetation coverage(FVC)were analyzed scientificaly to improve coordinated development of the social economy and ecological environmental quality while balancing development of the regional economy,in order to provide a reference for government departments to use in protecting and restoring regional ecological management.[Methods]Hubei Province was selected as the research area.Landsat remote sensing images and land use remote sensing data from 2000 and 2020were obtained,and methods such as spatial processing of remote sensing data,apixel binary model,and a land use transfer matrix were used.The temporal and spatial changes in FVC,land use type changes,and their effects on FVC in Hubei Province were analyzed.[Results]① From 2000to 2020,the area of cultivated land,grassland,and unused land in Hubei Province decreased,the area of water and construction land increased,and the area of forest land remained basically unchanged.The land use area sizes followed the order of forest land>cultivated land> water area>construction land>grassland>unused land;② The average FVC in Hubei Province increased by 6.50%.The average FVC of forest land,cultivated land,grassland,and unused land increased,while the average FVC of construction land decreased.③ FVC in Hubei Province showed an overall increasing trend.The areas with increased FVC were mainly concentrated in the west and southeast parts of Hubei Province.Some areas also experienced vegetation degradation,mainly concentrated in the central and southern parts of Hubei Province and some areas in Northern Xiangyang.④ During the FVC transfer process resulting from changes in land use types,the transfer process between higher FVC and high FVC areas of cultivated land was the most intense.The FVC transfer amount in forest land accounted for 47.87%of the total transfer amount,while the FVC transfer amount for grassland accounted for only a small proportion of the total transfer amount(3.40%).[Conclusion]Land use changes in Hubei Province were great from 2000to 2020,resulting in an overall increase in FVC over time.
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[目的]评估河北省生态产品价值(EPV),探索其空间演变背后的驱动因子,为构筑京津冀生态安全屏障,加快生态文明建设提供科学依据。[方法]基于当量因子法核算2010,2015,2020年河北省168个县区的EPV,利用全局莫兰指数、高/低聚类指数、热点分析法分析其空间分布演变和聚类演变特征,并借助地理探测器探测其主要驱动力。[结果]①2010—2020年河北省EPV均突破3.80×10~(11)元,整体上大幅提高,呈先平稳后急速上升的态势,到2020年突破4.20×10~(11)元;林地EPV最高,始终是所占比例最大的生态产品类型,水域次之且始终是变化量和变化率最大的类型。②2010—2015年EPV空间分布呈现出北高南低,西高东低的特征,高值集中于北部的燕山、坝上高原地区和西部的太行山地区,低值集中于东南部的河北平原地区;2015—2020年呈现出北高南低,东西高,中部低的特征。③2010—2020年空间聚类表现为显著高值集聚,冷热点分布呈现与空间分布相似的规律。④从单因子探测看,CO表面浓度、O_3浓度、年均气温是EPV空间演变的主导因子,人均GDP次之,社会因子的解释力相对最弱;从双因子交互探测看, 3期中起主导作用的组合因子分别是人均GDP∩NO_2表面浓度、高程∩O_3浓度和人均GDP∩CO表面浓度,其解释度(q值)分别为0.71,0.73,0.66。[结论]林地和水域对提高生态产品价值具有重要作用,但空间上差距较大,为使其产生更加积极变化,不仅要考虑生态单因子的强大驱动力,也应充分认识驱动力来源的复杂性和非线性。
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[Objective]The ecological product values(EPV)in Hebei Province were evaluated and the driving factors of their spatial change were also explored,in order to provide a scientific foundation for establishing an ecological security barrier in the Beijing-Tianjin-Hebei region while expediting ecological civilization development.[Methods]The EPV were computed for 168counties in Hebei Province during 2010,2015, and 2020by use of the equivalent factor method.Spatial distribution evolution and clustering characteristics were analyzed utilizing the global Moran index,high/low clustering index,and the hotspot analysis method. Geographic detector was employed to identify the primary driving forces.[Results]① Between 2010and 2020,Hebei Province’s EPV surpassed 3.80×10~(11) yuan,exhibiting notable overall improvement.EPV exhibited a pattern of gradual increase followed by rapid growth,exceeding 4.20×10~(11) yuan by 2020.Forest land had the highest EPV,consistently dominating the ecological product types.Water areas had the next highest EPV,and experienced the most substantial changes in both amount and rate.② During 2010to 2015,EPV’s spatial distribution exhibited a north-south and west-east dichotomy,with high values concentrated in the Northern Yanshan and Bashang Plateau regions,as well as in the Western Taihang Mountain area,while lower values clustered in the Southeastern Hebei Plain.During 2015to 2020,the north-south divide persisted,with added east-west variation and central low values.③ From 2010to 2020, significant high-value clustering was observed spatially,mirroring the distribution pattern of cold and hot spots.④ Single-factor analysis identified CO surface concentration,O_3concentration,and average annual temperature as primary influencers of EPV’s spatial evolution.Per capita GDP emerged as the secondary vital factor,while the impact of social factors remained comparatively weak.Dual-factor interaction analysis revealed that the leading combinations of factors during the three periods were per capita GDP∩ NO_2surface concentration,elevation ∩ O_3 concentration,and per capita GDP ∩ CO surface concentration,with corresponding q values of 0.71,0.73,and 0.66,respectively.[Conclusion]While forest land and water areas hold pivotal roles in augmenting EPV,significant spatial disparities exist.To drive more positive transformations,it is essential to not only consider robust ecological single-factor drivers,but also to comprehensively grasp the intricate and nonlinear nature of driving force origins.
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[目的]矿山开采促进地方经济的同时,也深刻影响着其周边的生态环境质量。基于多源长时序遥感数据,监测并定量评估矿山及周边区域的生态状况,为绿色矿山建设与可持续发展服务,也为矿山区域的生态恢复治理起积极的示范作用。[方法]以甘肃省永靖县智慧矿山及周边5km范围区域为研究区,基于矿山2009—2022年间5期Landsat系列卫星多光谱遥感影像,以及同期多幅高分系列卫星、Planet系列卫星等高分辨率遥感影像,监测识别矿区及其周边的重要地表变化和时间节点,并对该区域2009—2022年间生态质量时空分布格局、变化特征、影响因素等进行系统研究。[结果]①甘肃省永靖县智慧矿山矿区的生态质量2009—2019年呈现持续降低,2019年后保持平稳的变化态势,矿区对周边区域生态质量的影响程度较小。②在永靖县矿区遥感生态指数的时序分析中,绿度、热度指标相较干度与湿度指标变化更为显著。③对废弃矿坑进行回填、平地、修整边坡等土地复垦的前期工作,可显著提高该区域的遥感生态指数值。[结论]遥感生态指数可以较为客观地反映矿区生态质量的实际状态,废弃矿坑的土地复垦、矿区地表作业向地下作业的转变等行动,可以有效地解决矿区生态质量随着采矿时间推移持续下降的问题。
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[Objective]While financial proceeds from mining can promote the local economy,mining also has aprofound impact on the surrounding ecological environmental quality.The ecological status of mines and their surrounding areas were monitored and quantitatively evaluated based on multi-source and long timeseries remote sensing data to serve for green mine construction and sustainable development,and also play a positive demonstration role with regard to ecological restoration and management of mine areas.[Methods] This study was conducted at intelligent mine sites and its surrounding area (within 5km)in Yongjing County,Gansu Province.Multi-spectral remote sensing images acquired by the Landsat series of satellites for five periods from 2009to 2022 were used with high-resolution remote sensing images from the highresolution series satellites and the planet series satellites during the same period to monitor and identify the important surface changes and time nodes of the mine and its surrounding area.The spatial and temporal distribution pattern,variation characteristics,and influencing factors of ecological quality in this region during this time period were also systematically determined.[Results]① The ecological quality of intelligent mine areas in Yongjing County continuously declined from 2009to 2019,and the remained stable after 2019. The mining area had little impact on the ecological quality of the surrounding area.② The spatial-temporal change analysis of the remote sensing ecological index for the mining areas at Yongjing County indicated that changes in greenness and heat indicators were more significant than changes in dryness and humidity indicators.③ The preliminary work of backfilling,leveling,and trimming slopes for land reclamation at abandoned mine sites can significantly increase the remote sensing ecological index value.[Conclusion]The remote sensing ecological index can objectively reflect the actual state of the ecological quality of a mining area.Actions such as land reclamation of abandoned mines and the transformation of surface operations to underground operations in mining areas can effectively solve the problem of continuously declining ecological quality in mining areas.
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[目的]对内蒙古自治区锡林郭勒盟草原生境质量动态变化及其影响因素进行研究,为该地区生态环境保护政策的制定和高质量发展提供科学理论依据。[方法]利用Google Earth Engine(GEE)平台和MODIS数据构建生态遥感指数(RSEI)评价研究区的生境质量,并运用Moran指数和地理探测器分析遥感生态指数(RSEI)的空间异质性和影响因素。[结果]①2000—2021年研究区的生境质量经历了先恶化后改善的过程。生态环境得到了较大程度的改善,中部的典型草原和东部的草甸草原生境质量较好,而西部的荒漠草原区生境质量较差。②5个年份的全局莫兰指数(global Moran’s I)均大于0.935,表明研究区内RSEI的空间分布呈高度正相关,主要呈现高高和低低聚类分布。③地理探测器结果显示,绿度是影响RSEI的主要因素,模型因子与自然因子之间的交互作用最为显著,其次是模型因子与社会经济因子的耦合。[结论]锡林郭勒盟东部的生境质量高值区应继续加强对生态环境的保护力度,西部的生境质量低值区要注重对荒漠草原的修复与治理,遏制沙漠向东扩张。
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[Objective]The dynamic changes in grassland habitat quality and its influencing factors in Xilingol League,Inner Mongolia were studied to provide a scientific theoretical basis for the formulation of ecological environmental protection policies and high-quality development in this area.[Methods]The remote sensing ecological index(RSEI)was constructed by using the Google Earth Engine(GEE)platform and MODIS data to evaluate the habitat quality of the study area.Spatial heterogeneity and influencing factors of RSEI were analyzed by using the Moran index and geographic detector.[Results]① The results demonstrated a temporal change in habitat quality in the study area,with quality initially deteriorating and later improving from 2000to 2021.The ecological environment significantly improved over time.Habitat quality was better in the typical steppe of central China and the meadow steppe of Eastern China,while it was worse in the desert steppe of Western China.② The global Moran’s I for the five-year study period exceeded 0.935, indicating a strong positive spatial correlation in the distribution of RSEI within the study area,primarily characterized by high-high and low-low cluster patterns.③ The geodetector results showed that greenness was the main factor affecting RSEI.The most significant influence on ecological environmental quality was the interaction between model factors and natural factors,followed by the coupling of model factors and socio-economic factors.[Conclusion]The areas of high-value habitat quality in the eastern region of the Xilingol League should continue to strengthen protection of the ecological environment,and the areas of lowvalue habitat quality in the west should focus on restoration and management of desert grasslands and on curbing the eastward expansion of desert.
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[目的]陕西省神木市是黄河流域生态保护建设的重要地区。分析该地区生态环境质量变化,为资源型城市神木市的生态环境治理、修复及绿色发展提供科学依据。[方法]选取2010,2015与2020年共3期Landsat遥感影像,利用主成分分析方法构建遥感生态指数(RSEI)作为生态环境评价指标,分析神木市生态环境质量时空演变格局,并通过地理探测器探究该地区生态环境驱动机制。[结果]①神木市生态环境质量持续恶化,RSEI指数下降幅度达到12.47%,在2010—2015年间下降最快;神木市生态环境质量很差与较差的面积增加幅度达到15.29%。②神木市生态环境质量恶化以西北部的风沙区率先增强,随后转向地势较低的东南部和东北部。同时,神木市生态环境质量以较差和一般为主,两者总和占据神木市总面积的67.09%。③植被覆盖度与绿度、湿度、干度及热度4个指标因素均表现出显著的驱动性,其中植被覆盖度解释力最高(达到62.4%),是神木市生态环境质量的主要驱动力;多因子交互也均表示出协同增强的作用,夜间灯光、人口密度、热度与植被覆盖度交互作用最强。[结论]神木市生态环境质量总体仍在进一步恶化,尽管前期退化得到遏制,但恶化区域在逐渐扩大,提高植被覆盖度可以有效增强神木市生态环境质量。为此应进一步落实植被绿化等生态保护措施,提升神木市高品质生态环境质量。
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[Objective]The changes of ecological environmental quality were analyzed at Shenmu City of Shaanxi Province,an important area for ecological protection and construction in the Yellow River basin,in order to provide a scientific basis for ecological environmental management,restoration,and green development in this resource-based city.[Methods]Landsat remote sensing images in 2010,2015,and 2020 were selected,and the remote sensing ecological index (RSEI) was constructed as an ecological environmental evaluation index by using the principal component analysis method to analyze the spatial and temporal evolution pattern of ecological environmental quality in Shenmu City.The ecological environmental driving mechanism in the area was determined by Geodetector.[Results]① The ecological environmental quality of Shenmu City deteriorated over time,with the decline in RSEI reaching 12.47%,decreasing the fastest from 2010to 2015.The area with poor ecological environmental quality in Shenmu City increased by 15.29%.② The ecological environmental quality in Shenmu City deteriorated first in the sandy area in the northwest(enhanced by wind),and then shifted to the southeast and northeast where the elevation was lower.Meanwhile,the dominant ecological environmental quality in Shenmu City was categorized as poor and fair.The area of those two categories occupied 67.09%of the total area of Shenmu City.③ The four indicator factors of vegetation cover and greenness,humidity,dryness,and heat were identified as significant drivers of ecological environmental quality in Shenmu City.Vegetation cover was the main driver of ecological environmental quality,accounting for 62.40%of the variation in ecological environmental quality.The multifactor interactions also all indicated synergistic enhancement,and the interaction between night light, population density,heat,and vegetation coverage was the strongest.[Conclusion]The overall ecological environmental quality in Shenmu City has been deteriorating over time.Although the previous degradation has been contained,the area of deteriorating ecological environmental quality is gradually expanding.Increasing vegetation cover can effectively enhance the ecological environmental quality in Shenmu City.Therefore, ecological protection measures such as vegetation greening should be further implemented to improve the ecological environmental quality in Shenmu City.
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[目的]以县域为单位对1980—2020年福建省耕地非农化时空演变特征进行系统研究,揭示福建省耕地非农化的空间分布、迁移规律和集聚特征,以期为福建省耕地资源保护与可持续利用提供依据。 [方法]基于福建省1980,1990,2000,2010,2020年5期土地利用数据,运用重心模型、空间自相关等方法分析福建省耕地非农化时空演变特征。[结果]①福建省耕地资源主要呈带状分布于东南沿海,且耕地面积随时间推移逐年减少。②福建省耕地非农化空间分布地域差异性显著,耕地非农化程度不断加剧,由东南沿海地区逐步向全省范围扩散。耕地非农化高等级区域主要分布在东南沿海地区和西北地区,以耕地转为建设用地、林地和草地为主要类型。③福建省耕地非农化重心偏离于几何中心,其分布具有非均衡性。耕地非农化重心主要位于该省几何中心东南方向,沿先西南后东南再西北的路径转移。福建省东南部地区的耕地非农化程度仍高于西北部地区,耕地非农化空间格局的总体趋势由东南部地区向西北部地区迁移。④福建省耕地非农化呈空间正相关性,空间集聚程度加深。“高—高”集聚和“低—低”集聚的空间变化对福建省耕地非农化空间自相关关系的格局演变起主导作用,“高—高”集聚由东南部地区向西北部地区转移,“低—低”集聚数量减少。[结论]福建省耕地非农化程度不断加深,空间聚集度加强及耕地非农化重心逐渐向西北地区移动。为确保粮食安全,兼顾经济发展,应采取合理措施保护耕地,实现耕地资源的可持续发展。
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[Objective]The spatiotemporal evolution characteristics of cultivated land non-agriculturalization in Fujian Province from 1980to 2020were systematically studied based on county scale area,and the spatial distribution,migration law,and aggregation characteristics of cultivated land non-agriculturalization in Fujian Province were revealed in order to provide a basis for the protection and sustainable utilization of cultivated land resources in Fujian Province.[Methods]Based on land use data of Fujian Province in 1980, 1990,2000,2010,and 2020,a center of gravity model and spatial autocorrelation methods were used to analyze the spatio-temporal evolution characteristics of the non-agriculturalization of cultivated land in Fujian Province.[Results]① The cultivated land resources in Fujian Province were mainly distributed in a beltshaped manner along the southeastern coast,and the area of cultivated land decreased year by year over time. ② The spatial distribution of cultivated land non-agriculturalization in Fujian Province exhibited significant geographical differences,and the degree of cultivated land non-agriculturalization has been increasing, gradually expanding from the southeast coastal area to the entire province.The high grade areas of cultivated land non-agriculturalization were mainly distributed in the southeast coastal area and the northwest area, with the conversion of cultivated land mainly into construction land,forest land and grassland.③ The gravity center of cultivated land non-agriculturalization in Fujian Province deviated from the geometric center,and its distribution was uneven.The center of gravity of cultivated land non-agriculturalization was mainly located to the southeast of the geometric center,shifting first to the southwest,then to the southeast,and then to the northwest.The degree of cultivated land non-agriculturalization in the southeastern part of Fujian Province was still greater than in the northwestern part of the province.The overall trend of the spatial pattern of cultivated land non-agriculturalization shifted over time from the southeastern part to the northwestern part of the province.④ Cultivated land non-agriculturalization in Fujian Province showed a positive spatial correlation and a deepening spatial clustering.The spatial changes of the “high-high”and “low-low” agglomeration played a dominant role in the evolution of the spatial autocorrelation of cultivated land nonagriculturalization in Fujian Province,with the“high-high”agglomeration shifting from the southeast to the northwest,and the“low-low”agglomeration shifting from the southeast to the northwest.The“high-high” agglomeration shifted from the southeastern region to the northwestern region,and the number of“low-low” agglomeration decreased.[Conclusion]The degree of non-agricultural land in Fujian Province is deepening, the degree of spatial aggregation is strengthening and the center of gravity of non-agricultural land is gradually moving to Northwest China.In order to ensure food security and take into account economic development,reasonable measures should be taken to protect cultivated land and realize sustainable development of cultivated land resources.
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[目的]基于江西省2000—2020年5期土地利用数据,分析生境质量时空演变特征和研究区域生境质量变化的主要因素,以期为江西省土地利用规划及区域生态系统服务优化提供参考。[方法]使用InVEST栖息地质量评估模型对江西省生境质量水平进行空间测度,利用全局Moran’s I指数分析生境质量时空关联性,并运用地理探测器模型捕捉影响生境质量的主导因子。[结果]①2000—2020年,江西省生境质量整体处于较高水平,但呈现缓慢下降趋势。②江西省生境质量具有较高空间正相关性,空间分布差异性逐渐增强。③自然—社会经济驱动体系中,土地利用类型因子中林地所占比例是影响生境质量的主控因子,各驱动因子间交互作用均为非线性增强,其中距建设用地距离和耕地比例两者交互作用最大。 [结论]江西省生境质量整体水平较高,空间分布差异明显,生境质量水平主要受土地利用类型的影响。
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[Objective]Based on the land use data of five periods in Jiangxi Province from 2000to 2020,the spatial and temporal evolution characteristics of habitat quality and the main factors of regional habitat quality change were studied,in order to provide references for land use planning and regional ecosystem service optimization in Jiangxi Province.[Methods]The InVEST habitat quality assessment model was used to measure the spatial habitat quality level in Jiangxi Province.The global Moran’s I index was used to analyze the spatiotemporal correlation of habitat quality.The Geodetector model was used to capture the dominant factors affecting habitat quality.[Results]① From 2000to 2020,the overall habitat quality in Jiangxi Province was at a relatively high level,but showed a slow downward trend.② The habitat quality in Jiangxi Province had a high spatial positive correlation,and the spatial distribution differences gradually increased.③In the natural socio-economic driving system,the proportion of forest land in land use type factors was the main controlling factor affecting habitat quality.The interactions between each driving factor were nonlinear enhancements,with the greatest interaction observed between the distance from construction land and the proportion of cultivated land.[Conclusion]The overall habitat quality level in Jiangxi Province was relatively high,with significant spatial distribution differences.Habitat quality level was mainly influenced by land use types.
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[目的]研究耕地可持续集约化与规模化耦合协调模式,为制定国土空间规划、乡村振兴、耕地保护等政策提供科学依据。[方法]以内蒙古自治区为例,基于研究区2006—2021年的土地利用实际,运用熵值法构建耕地可持续集约化与规模化评价指标体系,采用多因子综合分析法对耕地可持续集约化与规模化进行测算,根据评价结果进行耦合协调性分析。[结果]2006—2021年内蒙古耕地集约化综合水平在0.218~0.370之间,总体呈上升趋势,空间特征为东西耕地集约化水平较高,中部较低。各盟市耕地集约化水平差距较小,耕地利用程度与产出效果对耕地集约化水平影响较为显著。耕地规模化综合水平在0.433 ~0.532内波动,总体呈现先上升后下降的趋势,空间分布特征不规律。各盟市耕地规模化水平差距较大,耕地斑块形状与面积对耕地规模化水平贡献度较高。在过去15a间,内蒙古耕地集约化与规模化的耦合度由磨合阶段逐步向高度磨合阶段发展,耕地集约化与规模化的耦合协调度持续增长,由濒临失调、勉强协调向初级协调、中级协调跃进,但仍有33.33%的盟市处于勉强协调阶段,空间分布格局大致为东西部较高,中部较低。[结论]内蒙古耕地利用水平存在优化空间,应更加注重对耕地科学利用,改善种植环境,将耕地利用与保护并重,促进内蒙古地区农业可持续高质量发展。
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[Objective]A coupling and coordination model of sustainable intensification and scale of cultivated land was studied to provide scientific basis for formulating policies such as territorial spatial planning,rural revitalization and cultivated land protection.[Methods]Actual land use for a study area in Inner Mongolia was used to construct an evaluation index system of sustainable intensification and scale of cultivated land by the entropy method,and the sustainable intensification and scale of cultivated land were measured by the multifactor comprehensive analysis method.A coupling and coordination analysis was carried out according to the evaluation results.Based on the evaluation results and regional status reported in the study area,we put forward specific suggestions for the utilization and protection of cultivated land in Inner Mongolia.[Results] The comprehensive level of cultivated land intensification in Inner Mongolia from 2006to 2021was between 0.218and 0.370,showing an overall upward trend.The level of cultivated land intensification was higher in the east and west,and lower in the central region.The differences in cultivated land intensification level among all of the cities were small,and the utilization degree and output effect of cultivated land had a significant influence on the level of cultivated land intensification.The comprehensive level of cultivated land scale fluctuated between 0.433and 0.532,showing a trend of initially increasing and then decreasing.The spatial distribution characteristics were irregular.There was a large difference in the scale level of cultivated land among the cities,and the shape and area of cultivated land patches had a high contribution to the scale level of cultivated land.During the past 15years,the coupling degree of cultivated land intensification and scale in Inner Mongolia gradually developed from the run-in stage to the high-level run-in stage,and the coupling degree of cultivated land intensification and scale continued to increase.The coupling degree of cultivated land intensification and scale has advanced from the verge of disharmony and barely coordinated to primary coordination and intermediate coordination.However,33.33% of cities were still in the barely coordinated stage,and the spatial distribution pattern was generally higher in the eastern and western regions and lower in the central region.[Conclusion]There is room for optimizing the cultivated land utilization level in Inner Mongolia.More attention should be given to the scientific utilization of cultivated land,improving the planting environment,and attaching equal importance to the utilization and protection of cultivated land to promote sustainable and high-quality agricultural development in Inner Mongolia.
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[目的]探究阿克苏河流域植被动态特征及其与潜在影响因子的响应关系,为干旱区生态环境保护和治理提供理论依据。[方法]基于MODIS归一化植被指数(NDVI)、气候、地形、土壤类型及土地利用等数据,利用趋势分析和地理探测器方法对2000—2020年阿克苏河流域植被动态及驱动机制进行分析。 [结果]①2000—2020年阿克苏河流域NDVI呈显著增加趋势,增速为0.003 2/a,且人类活动区增速显著大于非人类活动区。②潜在因子对NDVI变化的解释力存在时间和空间差异;土地利用转化是人类活动区NDVI变化重要驱动因子,海拔、土壤类型、距冰川积雪距离、距水体距离是非人类活动区NDVI变化重要驱动因子。因子间交互作用可以提高对NDVI变化的解释力,在人类活动区土地利用转化与土壤类型的相互作用对NDVI变化的解释力最强;背景因子、距补给水源的距离与其他因子的交互是非人类活动区NDVI变化的重要因子组合。③2000—2020年阿克苏河流域超过10%的面积发生土地利用转化,主要表现为裸地和草地的相互转化,耕地、林地、灌木地、人造地表面积显著增加。[结论]阿克苏河流域人类活动区和非人类活动区NDVI变化时空特征及驱动机制存在差异,应因地制宜,合理管理,促使该流域生态环境良性发展。
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[Objective]The characteristics of vegetation dynamic changes and their response relationship with potential impact factors in the Aksu River basin were determined in order to provide a theoretical basis for ecological environmental protection and governance in arid areas.[Methods]Based on MODIS normalized difference vegetation index(NDVI),climate,topography,soil type,and land use data,the dynamics and driving mechanisms of vegetation changes in Aksu River basin from 2000to 2020were analyzed using trend analysis and geographical detector methods.[Results]① The NDVI of the Aksu River basin showed a significant increasing trend from 2000to 2020,with a growth rate of 0.003 2/yr.The growth rate in the anthropogenic areas was significantly larger than in the non-anthropogenic areas.② There were temporal and spatial differences in the explanatory power of potential factors for NDVI changes.Land use conversion was an important driving factor for NDVI changes in anthropogenic areas.Elevation,soil type,distance from glacier snowpack,and distance from water bodies were important driving factors for NDVI changes in nonanthropogenic areas.Interaction among factors increased the explanatory power of NDVI changes,and land use conversion interacting with soil type had the strongest explanatory power of NDVI changes in the anthropogenic areas.The interaction among background factors,distance from recharge water sources and other factors was an important combination of factors for NDVI changes in the anthropogenic areas.③ More than 10%of the area of the Aksu River basin in 2000—2020underwent land use conversion,mainly in the form of mutual conversion of bare land and grassland,and a significant increase in the area of cropland, woodland,shrubland,and man-made land surface.[Conclusion]The spatial and temporal characteristics and driving mechanism of NDVI change in human activity area and non-human activity area in Aksu River basin are different.It is necessary to manage the Aksu River basin reasonably according to local conditions to promote the benign development of ecological environment in the basin.
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[目的]研究区域生态系统服务价值和生态风险变化及影响,为土地资源合理利用及国土空间生态修复提供决策支持。[方法]以Landsat遥感影像为数据源,使用GEE(Google Earth Engine)平台随机森林分类方法对云南省昆明市1990—2020年的土地利用变化信息进行提取,基于解译结果进行空间动态变化分析,采用当量因子法估算生态系统服务价值,运用生态风险模型揭示生态风险变化趋势,并借助双变量空间自相关模型计算二者的相关性。[结果]①1990—2020年,昆明市土地利用类型中林地和草地占地面积最大,建设用地面积明显增加,耕地、草地和林地面积减少。②昆明市生态系统服务价值总体呈逐年上升趋势,共上升3.08×10~8元,生态保护政策的有效实施对生态系统服务价值的提升有积极作用;研究期间生态风险以中、低风险为主,占总面积的79%,生态风险总体均值下降了0.12,城市经济发展与环境保护向良性态势发展。③生态风险对生态系统服务价值变化具有一定的影响。随着时间的推移,高价值—高风险区面积逐渐减少,低价值—低风险区面积逐渐增加,无明显极值。[结论]将区域生态系统服务价值和生态风险结合,能够较好地刻画昆明市人类活动所引起的生态环境状况的改变,为环境保护和高质量的可持续发展提供决策管理参考,有效防范生态风险,使昆明市经济发展与环境保护向良性态势发展。
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[Objective]The changes and impact of regional ecosystem services and ecological risks were studied in order to provide decision-making support for the rational utilization of land resources and ecological restoration of territorial space.[Methods]Landsat remote sensing images were used with the random forest classification method of the GEE(Google Earth Engine)platform to extract land use change information for Kunming City,Yunnan Province from 1990to 2020.A spatial dynamic change analysis was carried out based on the interpretation results.The equivalent factor method was used to estimate ecosystem service values.An ecological risk model was used to determine the change in ecological risk over time.The correlation between ecosystem service value and ecological risk was calculated with a bivariate spatial autocorrelation model. [Results]① Among the land use types in Kunming City from 1990to 2020,forest land and grassland occupied the largest area,the area of construction land increased significantly,and the area of cultivated land,grassland,and forest land decreased.② The value of ecosystem services in Kunming City showed an overall upward trend over time,with a total increase of 3.08×10~8 yuan.The effective implementation of ecological protection policies increased the value of ecosystem services.Ecological risks during the study period were mainly classified as medium and low risks,and accounted for 79%of the total area.The overall average ecosystem service value decreased by 0.12,indicating that urban economic development had developed with little impact on the environment.③ Ecological risk had a certain impact on the change of ecosystem service value,and with the passage of time,the area of high-value and high-risk areas gradually decreased,and the area of low-value and low-risk areas gradually increased,without obvious extremes.[Conclusion] The combination of regional ecosystem service value and ecological risk can better characterize changes in ecological environment of Kunming City caused by human activities,and provide decision-making and management references for environmental protection and high-quality sustainable development.effectively prevent ecological risks,and make the economic development and environmental protection of Kunming City develop to a benign situation.
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[目的]系统分析退耕还林以来植被覆盖时空变异特征,评估植被恢复的潜力,为陕西省生态环境建设的可持续发展提供科学的理论依据和实施建议。[方法]以MODIS NDVI数据为基础,采用Sen+ Mann-Kendall模型和Hurst指数探究了2000—2020年陕西省及秦巴山区、关中平原和黄土高原3个亚区植被覆盖度(fractional vegetation cover,FVC)的时空变化特征,并运用相似生境法测算了不同区域的植被恢复潜力。[结果]①2000—2020年陕西省FVC增长率为0.002 9/a,74.58%的区域有所改善。其中:黄土高原区FVC改善面积达84.46%,且以显著改善为主;秦巴山区FVC改善面积为74.40%,以轻微改善为主;而关中平原区FVC具有退化趋势,退化区域占64.56%。②全省FVC持续性改善面积占19.80%,黄土高原区和秦巴山区以持续性改善为主,面积比例分别为27.83%和13.68%,而关中平原区以持续性退化为主。③黄土高原区西北部及其与关中平原接壤地带的植被恢复空间较大,而子午岭林区植被恢复空间较小;秦巴山区森林覆盖率较高,几乎没有恢复空间;关中平原受城市化的影响,植被恢复空间小。[结论]近几十年来,陕西省植被覆盖度显著提高,但受气候、地形、植被类型和人类活动等因素的影响,植被覆盖变化具有明显的空间异质性。陕西省植被恢复的增长速度趋于放缓,持续改善能力已经较低,植被覆盖趋于平稳,但是黄土高原西北部地区及其与关中平原的接壤处植被覆盖恢复潜力仍较大。
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[Objective]The spatio-temporal variation characteristics of vegetation cover since returning farmland to forest were systematically analyzed.The potential of vegetation restoration were evaluated,in order to provide scientific theoretical basis and implementation suggestions for the sustainable development of ecological environment construction in Shaanxi Province.[Methods]The spatial and temporal variations of fractional vegetation cover(FVC)were investigated from 2000to 2020based on MODIS NDVI data,the Sen+Mann-Kendall method and Hurst index.Vegetation restoration potential was assessed by using the ‘similar habitat method’in Shaanxi Province,as well as in three subregions of the Loess Plateau,Qinling- Bashan Mountain,and the Guanzhong Plain.[Results]① The average growth rate of FVC in Shaanxi Province was 0.002 9/a from 2000to 2020,and 74.58%of the area had increased in FVC.Areas of significant and slight FVC increase were detected in the Loess Plateau and Qinling-Bashan Mountain where 84.46%and 74.40%of the areas,respectively,showed increased FVC.Slight FVC degradation trends were detected in the Guanzhong Plain where 64.56% of the area,showed decreased FVC.② The areas showing persistent increase in FVC accounted for 19.80%of the entire Shaanxi Province,and accounted for 27.83%and 13.68% in the Loess Plateau and Qinling-Bashan Mountain,respectively.The area showing persistent decreases in FVC were predominantly in the Guanzhong Plain.③ For the Loess Plateau region,greater vegetation recovery potential areas were detected in the northern area and the transitional area with the Guanzhong Plain,and the vegetation recovery potential was low in the Ziwuling forest area.Low vegetation recovery potentials were found in the Qinling-Bashan Mountain and Guanzhong Plain areas because of the high vegetation coverage background and the high rate of urbanization,respectively.[Conclusion]Shaanxi Province experienced significant FVC increases during 2000—2020due to it being a key region of ecological project implementation.However,the heterogeneous spatial-temporal variation of FVC was affected by climate,topography,plant species,and human activities.The growth rate of vegetation restoration in Shaanxi Province tended to slow down,the continuous improvement ability has been lower,and the vegetation cover tended to be stable.However,the northwest region of the Loess Plateau and its border with Guanzhong Plain still has a large potential for vegetation cover restoration.
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[目的]土壤侵蚀是全球性的重要环境问题,严重制约了人类的生产和生活。定量研究土壤保持服务价值为区域水土保持措施的制定,哈尔滨市水土保持功能分区规划提供科学依据。[方法]基于InVEST模型泥沙输移比例模块,对哈尔滨市2000,2010,2020年的土壤侵蚀量和土壤保持量进行评估,借助空间自相关法分析土壤保持量的空间聚集类型,并利用参数最优地理探测器揭示其空间异质性形成的驱动力。[结果]①2000,2010,2020年哈尔滨市土壤保持量分别为2.18×10~9,2.07×10~9,2.77×10~9 t,呈现先减少后增加的趋势,整体呈现“西低东高”的空间分布格局;②土壤保持量呈现强烈的空间正相关,以低—低聚集和高—高聚集类型为主,低—低聚集类型面积呈现下降趋势,而高—高聚集类型则呈现先降低后上升的趋势;③高程、降水量和坡度对哈尔滨市土壤保持量空间异质性的解释力最强,平均解释力分别为0.225 9,0.198 9,0.180 4,其中坡度和降水量与其他因子的交互作用,是研究区解释力最强的交互因素。 [结论]哈尔滨市应加强对城市西部和松花江沿岸的水土治理,同时维持城市北部和东部良好的水土状况,避免大规模的人类干扰活动。
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[Objective]Soil erosion is an important environmental problem of globality,which seriously restricts human production and life.Soil maintenance conservation founction was quantitative studied to formulate the regional soil and water conservation measures,and provide scientific basis for the functional partition planning and governance of Harbin City.[Methods]Based on the InVEST model sediment delivery ratio module,this study evaluated the soil erosion and soil conservation in 2000,2010and 2020in Harbin, analyzed the spatial aggregation type of soil conservation with the help of spatial autocorrelation,and used the optimal geographic detector to reveal the driving forces of spatial heterogeneity.[Results]①In 2000, 2010and 2020,the soil conservation in Harbin City was 2.18×10~9,2.07×10~9,and 2.77×10~9 t,respectively, showing a trend of decreasing first and then increasing,and the overall spatial distribution pattern of“low in the west and high in the east”.② The soil conservation amount showed a strong spatial positive correlation, mainly“low-low aggregation”and “high-high aggregation”types,the “low-low aggregation”type area showed a downward trend,while the “high-high aggregation”type showed a decreasing and then rising trend.③ Elevation,precipitation and slope had the strongest explanatory power on the spatial heterogeneity of soil conservation in Harbin City,with average explanatory forces of 0.225 9,0.198 9and 0.180 4, respectively,and the interaction between slope and precipitation and other factors was the strongest explanatory interaction factor in the study area.[Conclusion]Water and soil management in the western part of Harbin City and along the Songhua River should be strengthened,while good water and soil conditions in the north and east of the city should be maintained to avoid large-scale human disturbance activities.
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[目的]建立兼顾区域本底差异的生态补偿模型,进一步明确京津冀生态补偿时空分异格局及其主导驱动因子,为政府部门制定环境保护与宏观经济政策提供参考。[方法]基于修正碳赤字,利用模型构建、空间相关性分析与地理探测器技术等方法构建了合理的生态补偿框架,分析和研究了2007—2020年的京津冀县域生态补偿的时空变异格局、空间自相关性、驱动因子排序和交互作用等内容。[结果]①京津冀县域2007—2020年碳排放量呈现“先增后减”的变化趋势,碳吸收量大体呈现持续增加的变化趋势。 ②修正前的京津冀县域碳赤字呈现东、南、西部高,而北部较低的U形格局,而修正后的碳赤字由于兼顾了区域间本底差异,在时空分布上更加均匀。③生态补偿额度冷点区域基本分布在京津冀东北部,热点区域分布在京津冀西南部,两者之间存在个别冷热点区域,整体呈现热点区域向东北方向移动,冷点显著区域向西南方向移动的趋势。④不同年份内影响生态补偿额变化的主要因子不同,2007,2012,2017和2020年这4a中影响京津冀县域生态补偿变化的主导影响因子分别为第三产业产值、财政收入、第二产业产值和人均生产总值;不同年份导致生态补偿变化的因素交互影响力不同,交互作用表现出先互相减弱后互相增强的反复效应。[结论]兼顾区域本底差异的生态补偿模型,对京津冀生态补偿时空分异格局及其主导驱动因子的分析具有一定的公平性,可为政府部门制定环境保护与宏观经济政策提供更精准的指导和建议。
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[Objective]An ecological compensation model taking into account regional background differences was established to further clarify the spatial and temporal differentiation pattern of ecological compensation and its leading driving factors in the Beijing-Tianjin-Hebei region,in order to provide to a reference for government departments to formulate environmental protection and macroeconomic policies.[Methods] Based on a modified carbon deficit,a reasonable ecological compensation framework was constructed using model construction,spatial correlation analysis,and GeoDetector technology,etc.The spatial and temporal variability pattern,spatial autocorrelation,driver ranking,and interaction of ecological compensation in the Beijing-Tianjin-Hebei region during the period of 2007to 2020were analyzed and investigated.[Results] ① Carbon emissions in the Beijing-Tianjin-Hebei region from 2007to 2020showed a pattern of“increasing and then decreasing”over time,and carbon sequestration generally showed a trend of continuous increase. ② The carbon deficit in the Beijing-Tianjin-Hebei region before the amendment showed a U-shaped pattern with high carbon deficits in the east,south,and west,and low carbon deficits in the north.After the amendment,the carbon deficits were higher in the east,south,and west due to low carbon deficits in the north.After the amendment,the carbon deficits were more evenly distributed in space and time due to the local differences between regions. ③ The cold spot area of the ecological compensation amount was basically located in the Northeast Beijing-Tianjin- Hebei region,and the hot spot area was located in the Southwest Beijing-Tianjin-Hebei region.There were individual cold and hot spot areas between the two areas.The hot spot area was moving to the northeast, while the cold spot area was moving towards the southwest.④ The main factors affecting the change of ecological compensation amount were different in different years,and the main factors affecting the change of the ecological compensation amount were different.Compensation amount changed in different years.The main factors affecting the changes in ecological compensation in the Beijing-Tianjin-Hebei region in 2007, 2012,2017,and 2020were tertiary industry output,financial revenue,secondary industry output,and per capita gross domestic product,respectively.The interactive influence of the factors leading to the changes in ecological compensation was different in different years.The interaction effect showed the repeated effect of decreasing each other and then increasing each other.The interaction effect was different in different years. [Conclusion]The ecological compensation model that takes into account regional background differences has a certain fairness to the analysis of the spatio-temporal differentiation pattern of ecological compensation and its leading driving factors in the Beijing-Tianjin-Hebei region,and provides more accurate guidance and suggestions for government departments to formulate environmental protection and macroeconomic policies.
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[目的]分析中国2000—2020年中国30个省(市、区)碳中和效应的变化特征和动态演进趋势,定量揭示农业农村生态环境特征和内在动因机理,为进一步推动中国农业农村“碳中和”进程提供理论依据。 [方法]基于大农业视角,运用排放系数法选取37类碳源和28类碳汇指标,测算了中国2000—2020年21期30个省(市、区)农业农村碳中和效应,揭示其时空分布特征,并采用Kernel-Density方法观测其动态演进特征。[结果]①中国农业农村碳中和效应呈平稳上升趋势,年均递增2.79%,环比增速总体处于波动上升态势,其中碳汇增速明显快于碳排放增速。②中国农业农村碳中和效应空间分布不均衡程度明显增加,呈“中间低四周高”的分布格局,省域差异明显:排在前10位的省(市、区)占全国碳中和效应的66.42%,而排在后10位的省(市、区)仅占全国的4.72%。③碳中和效应水平呈现:中部地区>东部地区>西部地区的态势,各地区间存在较大差异,种植业是减排增汇的最大源头。④中国农业农村碳中和效应密度函数曲线中心整体向右偏移,各省(市、区)空间差距逐步扩大,存在区域发展不均衡的现象。[结论]低碳经济与现代农业相互交织,各地区应当因地制宜地制定农业农村领域碳中和发展规划,实现区域间碳中和协同机制,加速农业农村碳中和进程。
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[Objective]The change characteristics and dynamic evolution trend of carbon neutral effect in 30 provinces(municipalities and regions)in China from 2000to 2020were analyzed,and the characteristics and internal motivation mechanism of ecological environment in agriculture and rural area were quantitatively revealed,in order to provide theoretical basis for further promoting the process of“carbon neutral”in agriculture and rural areas of China.[Methods]Based on the perspective of large agricultural production systems,37types of carbon sources and 28types of carbon sinks were selected by the emission coefficient method to calculate the carbon neutrality effect for agriculture and rural areas in 30provinces(municipalities and regions)in China during 2000—2020.The spatial and temporal distribution characteristics of the carbon neutrality effect were determined,and its dynamic evolution characteristics were observed by the Kernel- Density method.[Results]① The carbon neutral effect in China’s agriculture and rural areas increased steadily over time,with an average annual increase of 2.79%.The overall growth rate fluctuated,and the growth rate of carbon sinks was significantly faster than the growth rate of carbon emissions.② The spatial imbalance of the carbon neutral effect in China’s agriculture and rural areas increased significantly,showing a distribution pattern of“lower in the middle and higher in the periphery”.The difference between provinces was obvious:the top 10provinces(municipalities and regions)accounted for 66.42%of the national carbon neutral effect,while the bottom 10provinces(municipalities and regions)accounted for only 4.72% of the national carbon neutrality effect.③ The level of the carbon neutrality effect showed a distribution trend of “central region > eastern region > western region”,and there were great differences between different regions.The planting industry was the largest source of emission reduction and sink increase.④ The center of the carbon neutrality effect density function curve in China’s agriculture and rural areas had shifted to the right as a whole,and the spatial gap between provinces(municipalities and regions)has gradually expanded. Unbalanced regional development was observed.[Conclusion]Low-carbon economy and modern agriculture are intertwined.All regions should formulate carbon neutral development plans in agriculture and rural areas according to local conditions,bring about an inter-regional carbon neutral coordination mechanism,and accelerate the process of carbon neutral in agriculture and in rural areas.
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[目的]探究“双碳”目标背景下黄淮海5省74市粮食生产碳排放效率并量化其空间分异及动态演变,旨在分析黄淮海5省粮食生产碳排放效率现状,促进黄淮海5省粮食绿色低碳生产。[方法]采用碳排放系数法和三阶段超效率SBM模型分别测算2011—2020年黄淮海5省74市粮食生产碳排放及碳排放效率,借助泰尔指数和核密度估计探究粮食生产碳排放效率的空间分异及动态演变。[结果]①研究期内,黄淮海5省市域粮食生产碳排放呈“M”型波动下降趋势,但下降缓慢;其中,化肥使用是导致粮食碳排放的主要原因。②黄淮海5省市域粮食生产碳排放效率呈先降后升的演变趋势,第一阶段效率均值为0.59,剔除环境变量和随机误差对效率值的影响,第三阶段效率均值为0.48,较第一阶段效率值下降18.6%;其中,滁州、驻马店、德州等地效率值较高,而黄山、威海等地效率值较低。③粮食生产碳排放效率空间差异呈上升趋势,区域内差异是影响总体差异的主要因素,其中河南省各市差异最为显著。④样本考察期内,核密度曲线由“单峰状”向“双峰状”转变,主峰呈波动上升且轻微右移趋势,侧峰隆起幅度较小,表明黄淮海5省粮食生产碳排放效率整体水平提高,地区差异增大,并呈多极化趋势发展。[结论]黄淮海5省粮食生产碳排放效率整体水平较低,有明显的空间分异特征,未来各地区应减少化肥等物资投入,并采用“对口帮扶”策略,促进各地区粮食生产技术良性互动,以缩小区域间粮食生产碳排放效率地区差异。
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[Objective]The carbon emission efficiency of grain production was determined for 74cities in the five provinces of Huang-Huai-Hai region,and spatial differentiation and dynamic evolution were quantified in light of the“double carbon”goals development strategy and goals.The current situation of carbon emission efficiency of grain production in the five provinces of Huang-Huai-Hai region was analyzed in order to promote green and low-carbon grain production in the region.[Methods]The carbon emission coefficient method and the three-stage super-efficiency SBM model were used to measure carbon emissions and carbon emission efficiencies of grain production for 74cities in the five provinces of Huang-Huai-Hai region from 2011to 2020.The spatial differentiation and dynamic evolution of carbon emission efficiency of grain production were then determined by means of the Theil index and kernel density estimation.[Results] ① Carbon emissions of grain production in the five provinces and cities of Huang-Huai-Hai region during the study period showed a fluctuating downward trend with an“M”shape,but the decline was slow.The use of chemical fertilizers was the main cause of grain carbon emissions.② The carbon emission efficiency of grain production in the five provinces and cities of Huang-Huai-Hai region initially decreased and then increased. The average efficiency of the first stage was 0.59.Excluding the influence of environmental variables and random errors on the efficiency value,the average efficiency of the third stage was 0.48,which was 18.6% lower than the efficiency value of the first stage.Chuzhou,Zhumadian,Dezhou,and other cities had higher efficiency values,while Huangshan,Weihai,and other cities had lower efficiency values.③ The spatial differences of the carbon emission efficiency of grain production was on the rise,and the differences within the region were the main factor affecting the overall difference,among which the difference between cities in Henan Province was the most significant.④ During the sample investigation period,the core density curve changed from a“single-peak shape”to a“double-peak shape”where the main peak showed a fluctuating rise and a slight shift to the right,and the secondary peak maximum was smaller,indicating that the overall level of carbon emission efficiency of grain production in the five provinces of Huang-Huai-Hai region had increased,regional differences had increased,and the region showed a multi-polar trend.[Conclusion]The overall level of carbon emission efficiency of grain production in the five provinces of Huang-Huai-Hai region was low,and there were obvious spatial differentiation characteristics.In the future,all regions should reduce the input of materials such as chemical fertilizers,and adopt the strategy of“counterpart assistance” to promote the positive interaction of grain production technology in various regions so as to narrow regional differences in the carbon emission efficiency of grain production among regions.
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[目的]探究片蚀泥沙轻组有机碳(LFOC)和重组有机碳(HFOC)不均匀富集的水动力学和碳同位素特征,为正确理解水蚀作用下土壤有机碳库变化提供理论与技术支撑。[方法]以陕西省咸阳市杨凌区土为研究对象,采用改进“三区”移动式变坡钢制土槽,结合人工模拟降雨技术,测定径流水动力学参数和泥沙各粒径团聚体有机碳组成及其δ~(13) C值,并辅以棕壤侵蚀泥沙有机碳δ~(13) C值和水力参数,验证土试验结果的准确性。[结果]①雨强和坡度较小时,侵蚀泥沙LFOC和HFOC易发生富集,且相较黏粉粒和微团聚体,大团聚体LFOC与HFOC含量受雨强和坡度的影响更大;②侵蚀泥沙黏粉粒中有机碳δ~(13) C值与其有机碳活跃分数(λ)呈负相关,而其他粒径团聚体有机碳δ~(13) C值与其λ呈显著正相关(p<0.05);③流速与黏粉粒λ显著正相关(p<0.05),雷诺数与各粒径团聚体有机碳δ~(13) C值均呈显著负相关(p<0.01),片蚀过程中流速越大,黏粉粒中LFOC越易于优先输移,而紊流加剧则促进低δ~(13) C值团聚体有机碳的优先输移; ④对于侵蚀泥沙黏粉粒,流速和雷诺数越大,其有机碳δ~(13) C值越小,λ越大;对于微团聚体和大团聚体,雷诺数越小,其有机碳δ~(13) C值与λ越大。[结论]片蚀过程中轻重组有机碳流失与流速和雷诺数密切相关。并进一步验证了13 C同位素对侵蚀泥沙有机碳示踪的有效性。
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[Objective]The hydraulic characteristics and 13C isotopic characteristics of the non-uniform enrichment of light(LFOC)and heavy(HFOC)fractions of soil organic carbon in sediments during the sheet erosion process were determined in order to provide theoretical and technical support for a better understanding of the dynamic changes in soil organic carbon stocks under water erosion.[Methods]This study was conducted on Lou soil from Yangling District of Xianyang City,Shannxi Province.An improved “three-zone”mobile steel soil pan was used together with an artificial rainfall simulator to measure runoff hydraulic parameters,organic carbon compositions of each aggregate size in sediments,and their relatedδ~(13)C values.Additionally,these results for Lou soil were verified based on theδ~(13) C values of organic carbon in eroded sediments and runoff hydraulic parameters for brown soil.[Results]① When rainfall intensity and slope were low,both LFOCand HFOCwere enriched in eroded sediments,and the organic carbon composition of macroaggregates were observed to be more susceptible to the influence of rainfall intensity and slope than observed for clay and silt particles and microaggregates.② Theδ~(13)C values of organic carbon in clay and silt particles were negatively correlated with the percentage of LFOCin SOC(λ),while theδ~(13)C values of organic carbon in other size aggregates showed a significant positive correlation withλvalues(p<0.05).③ Flow velocity was positively correlated withλvalues of clay and silt particles(p<0.05),while Reynolds number was negatively correlated withδ~(13) C values of clay and silt particles,microaggregates,and macroaggregates (p<0.01).Increasing flow velocity during sheet erosion promoted the preferential transport of clay and silt size organic carbon,while turbulence promoted the transport of organic carbon with lowδ~(13) C values in aggregates;④ For clay and silt particles,the larger the flow velocity and Reynolds number,the smaller the δ~(13) C value of organic carbon and the larger theλ were.For microaggregates and macroaggregates,the smaller of Reynolds number,the larger theδ~(13) C values of organic carbon andλvalues in microaggregates were.[Conclusion]The loss of LFOCand HFOC was closely related to flow velocity and Reynolds number during the sheet erosion process.The effectiveness of using the 13C isotope in tracing organic carbon in eroded sediments was verified.
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[目的]探究珠三角地区2005—2020年土地利用变化及其对碳储量的影响,并对2035年珠三角的土地利用格局和碳储量进行模拟预测,以期为珠三角地区“双碳”目标下的国土空间规划和生态决策提供科学依据。[方法]基于2005—2020年4期土地利用数据,以珠三角城市群为研究区域,采用PLUS模型和InVEST模型对该区的土地利用变化和碳储量演变进行分析,并预测其2035年土地利用空间格局和碳储量变化趋势。[结果]①2005—2020年,珠三角地区碳储量先增加后减少,林地、建设用地和未利用地增多促进碳储量增长了4.82×10~7 t,耕地、草地和水域减少导致碳储量减少了5.10×10~7 t。②预计2035年,随着建设用地和林地的增加,该区碳储量较2020年增长5.75×10~7 t,生态环境向好发展。③该区碳储量表现出“四周高,中部低”的空间分布格局,与土地利用空间分布具有显著一致性,即碳储量高值区集中在林地、耕地和草地,碳储量低值区集聚在建设用地。[结论]随着未来城市发展需要,政府部门应进行土地综合开发利用,采取生物、工程技术等生态修复措施,提升区域固碳能力,助力实现碳中和目标。
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[Objective]The land use change and its impact on carbon storage was studied from 2005to 2020, and the land use pattern and carbon storage in the Pearl River Delta in 2035were simulated and predicted,in order to provide a scientific basis for the territorial spatial planning and ecological decision-making under the dual carbon goal in the Pearl River delta region.[Methods]Based on land use data for four periods from 2005 to 2020,land use change and carbon storage evolution in the Pearl River delta urban agglomeration were analyzed by using the PLUS model and the InVEST model.The spatial pattern of land use and the carbon storage change trend in 2035 were predicted.[Results]① From 2005to 2020,carbon stocks initially increased and then decreased.The increased area of forest land,construction land,and unused land increased carbon stocks by 4.82×10~7 t,and the decreased area of cultivated land,grassland and water area decreased carbon stocks by 5.10×10~7 t.②In 2035,with an expected increase of construction land and forest land, carbon storage will increase by 5.75×10~7 t compared with 2020,and the ecological environment will improve. ③ Carbon storage showed a spatial distribution pattern of“higher in the surrounding areas and lower in the middle”that was significantly consistent with the spatial distribution of land use,i.e.,the high-value carbon storage areas were concentrated in forest land,cultivated land,and grassland,and the low-value carbon storage areas were concentrated in construction land.[Conclusion] With the needs of future urban development,government departments should carry out comprehensive land development and utilization, adopt ecological restoration measures based on biological and engineering technology,and improve regional carbon sequestration capacity so as to achieve carbon neutrality.
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[目的]探究辽宁省“三生”功能时空演变及其碳排放效应,为“双碳”目标下的国土空间规划提供依据。[方法]基于土地利用多功能性分类识别辽宁省国土“三生”功能,结合直接和间接排放因子法核算碳排放量,探索“三生”功能与碳排放量空间关系及其时空分异性,揭示“三生”功能时空演变的碳排放效应。[结果]①2005—2020年辽宁省“三生”功能空间分布格局总体变化不大,大部分地区以生产和生态功能为主,生活功能区扩张明显,各地级市中心与周边区域空间差异明显。②2005—2013年,辽宁省各县域碳排放量增长迅速,2013—2020年增速缓慢,但空间差异愈发显著,碳排放高值明显集中在沈阳市和大连市。③辽宁省“三生”功能与碳排放量空间布局及数量变化的相关性总体较强,但空间差异明显且影响因素复杂。[结论]辽宁省各县域需要在自然地理条件约束和经济社会发展需求引导下,在明确各自土地主导功能定位的基础上,依托自身区域优势与资源禀赋,加强区域协作,以实现全域碳减排。
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[Objective]The carbon emission effect on changes of the productional-living-ecological functions was determined in order to provide a reference for territorial and spatial planning meeting the“dual carbon” goals of“carbon peak”and“carbon neutrality”.[Methods]The evaluation assignment method,the energy consumption method,and a geographical weighted regression model were used to determine the spatialtemporal evolution characteristics of the productional-living-ecological functions and their effects on carbon emissions in Liaoning Province from 2005to 2020.[Results]① The spatial distribution pattern of the productional-living-ecological functions in Liaoning Province did not change much from 2005to 2020.Most of the areas were dominated by productional and ecological functions,the living function areas expanded significantly,and the spatial differences mainly occurred between the central urban area and the surrounding areas.② From 2005to 2013,the carbon emissions of counties in Liaoning Province increased rapidly,and from 2013to 2020,the growth rate was slower but its spatial differences became more obvious.The high carbon emissions were significantly concentrated in Shenyang and Dalian cities.③ The overall correlations between the productional-living-ecological functions and carbon emissions were strong.The spatial differences were obvious and the influencing factors were complex.[Conclusion]Under the constraints of natural conditions and guided by their social and economic development needs,counties in Liaoning Province need to clearly define the main functions of the land and promote regional cooperation on the basis of their own advantages and resource endowments so as to realize carbon emission reductions over the entire region.
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[目的]评估广西壮族自治区茅尾海土地利用与碳储量的时空变化特征,为促进增碳汇与可持续发展提供科学依据。[方法]使用监督分类的方法对茅尾海2009,2015和2021年的3期遥感影像数据进行解译提取,基于ArcGIS软件和InVEST模型对茅尾海土地利用变化与碳储量演化进行研究。[结果] ①茅尾海土地类型主要呈现“大聚居,小杂居”的分布特点,2009—2021年耕地、浅海水域和渔业养殖区面积减少,红树林湿地、建筑用地、林草地、淤泥质滩涂面积增加;②茅尾海碳储量呈先下降后上升趋势, 2009—2015,2015—2021,2009—2021年区域碳储量变化量分别为-1.10×10~5,3.77×10~4,-7.29×10~4 t;碳固定净现值分别为-1.37×10~8,4.66×10~7,-9.01×10~7元;③2009—2021年,茅尾海主要为渔业养殖区、林草地等高固碳土地利用类型向建筑用地等低固碳类型的转变,转为建筑用地造成的碳储量损失最大,达2.85×10~5 t;转为渔业养殖区增加的碳储量达1.81×10~5 t。[结论]加快推动茅尾海养殖方式转型升级,加强红树林在宜林区域的增殖及加快森林城市建设,有利于研究区域固碳与可持续发展。
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[Objective]Changes in land use and carbon storage in Maowei Sea of Guangxi Zhuang Autonomous Region were analyzed in order to provide a scientific basis for increasing its carbon sink capacity and improving its ecological value.[Methods]The supervised classification method was used to interpret and extract remote sensing image data for Maowei Sea in 2009,2015,and 2021.ArcGIS and the InVEST model were used to analyze spatiotemporal changes in land use and carbon storage in Maowei Sea.[Results]① The land use types in Maowei Sea mainly showed the distribution characteristics of“large settlement,small mixed residence”.The areas of cultivated land,shallow sea waters,and fishery breeding areas decreased,and the areas of mangrove wetlands,building land,forest grassland,and silty tidal flats increased from 2009to 2021.② Carbon storage initially decreased and then increased over time.Changes in net carbon sequestration and its net present value in Maowei Sea were,respectively,-1.10×10~5 tons and-1.37×10~8 yuan,3.77×10~4 tons and 4.66×10~7 yuan,and-7.29×10~4 tons and-9.01×10~7 yuan in 2009—2015,2015—2021and 2009—2021.③ The conversion from high carbon sequestration land use types(fishery breeding areas and forest and grasslands)to low carbon sequestration land use types(building land)in Maowei Sea in 2009—2021caused the largest carbon storage loss,reaching 2.85×10~5 t.The conversion to fishery breeding areas increased carbon storage by 1.81×10~5 t.[Conclusion]Accelerating the conversion and upgrading of farming methods, increasing the proliferation of mangrove forests in terrestrial and aquatic forested areas,and accelerating the construction of forest cities will promote carbon sequestration and sustainable development in Maowei Sea.
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[目的]探究土地利用/覆被变化对区域生态系统碳储量及生态系统脆弱性的影响,以期为区域绿色低碳和生态系统的可持续发展提供参考依据。[方法]以2000,2010,2020年黔中城市群核心经济区3期土地利用/覆被数据为基础,运用InVEST模型和土地利用转移矩阵定量分析生态系统碳储量及其空间分布格局,并采用潜在影响指数(PI)对区域生态系统服务脆弱性进行评估。[结果]①2000—2020年,黔中城市群核心经济区土地利用/覆被变化总体表现为耕地和林地持续下降,建设用地持续上升。研究区土地利用/覆被转移主要表现为耕地、林地、草地向其他地类的转移,其中,2000—2010,2010—2020年分别有3 339.35,3 669.15km~2土地发生了转移,前者林地转为草地是主要转移类型,后者耕地转为建设用地为主要转移类型。②2000—2020年区域的碳储量表现为减少趋势,由4.42×10~7 t减小到4.33×10~7 t,累计减小9.40×10~5 t,林地转为草地是引起碳储量减少的主要原因。各年度碳储量密度均呈现西部、东部高,中部低的分布态势;20a间,高密度区未发生明显变化,低密度区表现为由中心区域向外围扩散。 ③2000—2020年黔中城市群核心经济区主要扮演碳源的角色,土地利用程度指数增加了2.83,PI指数分别为-0.04,-0.31,均表现为负面潜在影响,且脆弱性不断增强。[结论]增加林地、控制林地转为其他用地及建设用地扩张是促进区域绿色低碳和生态系统的稳定可持续发展的重要手段。
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[Objective]The impacts of land use/cover changes on carbon storage and ecosystem vulnerability in regional ecosystems were determined in order to provide a reference for regional green low-carbon and sustainable development of ecosystems.[Methods]The ecosystem carbon storage and its spatial distribution pattern were quantitatively analyzed by using land use/cover data for the core economic zone of the Central Guizhou urban agglomeration in 2000,2010,and 2020with the InVEST model and a land use transfer matrix.A potential impact index(PI)was used to assess the vulnerability of regional ecosystem services. [Results]① Land use/cover changes in the core economic zone of the Central Guizhou urban agglomeration showed that cultivated land and forest land continued to decline from 2000to 2020,and construction land continued to increase.Land use/cover changes in the study area were mainly manifested as the transfer of cultivated land,forest land,and grassland to other land use types,among which 3 339.35and 3 669.15km~2 of land were transferred from 2000to 2010and 2010to 2020,respectively.The conversion of forest land to grassland was the main transfer type during the first period,and the conversion of arable land to construction land was the main transfer type in the second period.② Regional carbon storage decreased from 2000to 2020 (from 4.42×10~7 to 4.33×10~7 t),with a cumulative decrease of 9.40×10~5 t.The conversion of forest land to grassland was the main reason for the reduction in carbon storage.The carbon storage density in each year was higher in the west and east,and lower in the middle portion of the study area.There was no significant change in the high density area during the past 20years,while the low density area spreading from the central area to the periphery.③ The core economic zone of the Central Guizhou urban agglomeration was the main source of carbon from 2000to 2020,with the land use degree index increasing by 2.83,and PI index being-0.04and -0.31,respectively,showing negative potential impact and increasing vulnerability. [Conclusion]Increasing forest land,controlling forest land conversion to other uses,and expanding construction land are important means for promoting regional green,low-carbon,stable,and sustainable development of ecosystems.
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[目的]预测黑龙江省大兴安岭地区蓝绿空间用地变化并分析其对碳储量的影响,为实现大兴安岭“双碳”目标提供科学参考。[方法]基于2015,2020年黑龙江省大兴安岭地区土地利用数据,通过二元Logistic回归检验的驱动因子引入PLUS模型,预测2030年蓝绿空间用地格局,耦合InVEST模型分析蓝绿空间变化对碳储量的影响,量化并验证蓝绿空间对碳储量波动的主要驱动地类。[结果]①2015—2030年蓝绿空间持续增长,林地均达蓝绿空间转入的60%以上,占绝对优势。②2015—2020年蓝绿空间占碳储量增长空间总面积的96.52%,2030年自然发展、蓝绿空间保护、城镇快速发展情景碳储量分别为1.459 4×10~9,1.483 1×10~9和1.464 7×10~9 t,主要为大量非蓝绿空间向林地、草地的转入,其中蓝绿空间保护对碳储量增加作用最明显。③蓝绿空间中林地、草地、水域聚集程度与碳储量呈显著正相关,林地、草地为碳储量变化第一、第二主导地类。[结论]未来应延续优良生态政策,对黑龙江省大兴安岭地区蓝绿空间进行重点保护,提高林地、草地结构完整性,助力该地区实现“双碳”目标。
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[Objective]The changes in blue-green space land use were predicted and their impacts on carbon storage in Daxing’an Mountains were analyzed in order provide scientific strategic for realizing the“dualcarbon” goal guidance references.[Methods]Based on land utilization data for Daxing’an Mountains in 2015 and 2020,the driving factors of a binary logistic regression test were introduced into the PLUS model to predict the blue-green space land utilization pattern in 2030.The InVEST model was coupled with the results to analyze the impact of changes in blue-green space on carbon storage.The main driving land types of bluegreen space causing changes in carbon storage were quantified and verified.[Results]① Blue-green space continued to grow from 2015to 2030.Forest land increased over this time period,accounting for more than 60%of the blue-green space transfer,indicating that forest land held an absolute advantage.②From 2015to 2020,blue-green space accounted for 96.52% of the total area of carbon storage growth space.Carbon storage for the natural development,blue-green space protection,and rapid urban development scenarios in 2030 were 1.459 4×10~9 t,1.483 1×10~9 t,and 1.464 7×10~9 t,respectively,mainly due to the transfer of a large amount of non-blue-green space to forest land and grassland.Protection of blue-green spaces had the most obvious effect on the increase of carbon storage.③ The degree of aggregation of forest land,grassland,and water areas in the blue-green space was significantly and positively correlated with carbon storage.Forest land and grassland were the first and second most dominant types of carbon storage changes.[Conclusion] Excellent ecological policies should be promoted in the future to protect the blue-green space and to improve the structural integrity of forest land and grassland so as to achieve the“dual-carbon”strategic goal in the Daxing’an Mountaions.
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[目的]探究黄河流域内蒙古段土地利用变化格局对碳汇空间分布的影响,并找出其主要驱动因素,为研究区生态空间发展方向和增汇政策提供依据。[方法]以黄河流域内蒙古段为例,基于2000,2010与2020年土地利用数据,使用InVEST-FLUS模型分析各期碳汇能力变化情况,进而模拟2040年自然发展、生态保护及农业优先3种不同情景下碳储量变化格局,并借助地理探测器找出造成碳汇空间分布差异背后的主要驱动因素。[结果]①2000—2020年,黄河流域内蒙古段碳储量呈先上升后下降态势,碳储量总体增加8.63×10~6 t,其中,地下生物碳储量增加3.91×10~6 t,土壤碳储量增加2.28×10~6 t。②未来自然发展情景下碳储量继续减少3.92×10~6 t,而在生态保护情景下增长2.21×10~7 t,高于农业优先情景下4.99×10~6 t的碳储增量,其中,土壤碳库是造成增量差异的关键。③年平均降雨量、年平均温度的不平衡分布是造成黄河流域内蒙古段各类碳库差异的主要因素。[结论]合理的生态保护政策更符合未来城镇集约化和生态高质量发展要求,未来应重视荒漠化防治工作,推进林草建设,为提升区域生态安全格局和增汇政策提供保障。
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[Objective]The influence of land use change patterns on the spatial distribution of carbon sinks for the Inner Mongolia section of the Yellow River basin was investigated,and the main driving factors behind the spatial distribution of carbon sinks were identified in order to provide a basis for directing ecological spatial development and for developing sink enhancement policies in the study area.[Methods]The study was conducted for the Inner Mongolia section of the Yellow River basin.InVEST-FLUS model was used to analyze changes in the carbon sink capacity during each period of the study based on land use data from 2000, 2010,and 2020.The patterns of carbon stock changes were simulated in 2040under three different scenarios (natural development,ecological conservation and agricultural priority),and identified the main driving factors behind the differences in the spatial distribution of carbon sinks with the help of geographic probes. [Results]① From 2000to 2020,carbon storage for the Mongolia section of the Yellow River basin initially increased and then decreased,with an overall increase of 8.63×10~6 t.Subsurface biological carbon storage increased by 3.91×10~6 t and soil carbon storage increased by 2.28×10~6 t.② Carbon storage continued to decrease by 3.92×10~6 t for the future natural development scenario,but increased by 2.21×10~7 t for the ecological protection scenario,which was higher than for the agricultural priority scenario(4.99×10~6 t).Soil carbon storage was the key factor causing the incremental difference.③ The unbalanced distributions of mean annual rainfall and mean annual temperature were the main factors causing differences in the various carbon pools for the Mongolia section of the Yellow River basin.[Conclusion]Reasonable ecological protection policies are more in line with the future requirements of urban intensification and ecological highquality development.Future attention should be given to preventing and controlling desertification,and to promoting forest and grassland construction so as to improve the regional ecological security pattern and carbon sink enhancement policies.
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细胞周期失调是肿瘤重要的标志之一,生物信息学分析结果表明,Trigger转座子衍生蛋白1(TIGD1)在临床肝癌组织中高表达且与细胞周期相关,但相关机制未知。为了探究TIGD1调控肝癌细胞生长的具体机制,首先,利用shRNA质粒构建靶向敲低TIGD1的肝癌细胞系Hep3B,并分析TIGD1敲低对肝癌细胞生长的影响,结果表明细胞生长受阻;接着,通过细胞流式技术分析TIGD1敲低对肝癌细胞周期进程的影响,结果显示,TIGD1敲低的Hep3B细胞系的细胞周期进程主要阻滞于G2/M期;然后,通过免疫沉淀(IP)实验验证TIGD1可能发生相互结合的蛋白分子,结果表明,TIGD1可能与Aurora激酶相互作用蛋白1(AURKAIP1)存在相互结合,进一步的Co-IP实验证实了TIGD1和AURKAIP1之间的相互作用。已知AURKAIP1可调控Aurora激酶A(AURKA)的蛋白酶体降解途径,AURKA是一种有丝分裂调控蛋白,与细胞周期进程密切相关。文中进一步探究TIGD1对AURKA蛋白水平的影响,实验结果表明,在TIGD1敲低的情况下,AURKA在Hep3B细胞系中的蛋白水平明显下调,mRNA水平没有明显变化。综上所述,TIGD1可能通过调控AURKA在肝癌细胞中的转录后水平来影响细胞周期进程,从而影响肝癌的发生发展。
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Cell cycle dysregulation is one of the most important hallmarks of cancer.Bioinformatics studies have suggested that trigger transposable element-derived 1 (TIGD1) is expressed at higher levels in the tumor tissues from the clinical hepatocellular carcinoma (HCC) samples and may be related to the cell cycle.However,the underlying mechanism is unclear.To explore the specific mechanism of TIGD1 regulating the growth of hepatocellular carcinoma cells,this paper first analyzed the growth of HCC cell line Hep3B with TIGD1 knockdown by using shRNA plasmid.The results show that cell growth is inhibited.Then,cell cycle analysis by flow cytometry was used to investigate the effect of TIGD1 knockdown on cell cycle of HCC.The results show that the cell cycle progression of the Hep3B cell line is mainly blocked in the G2/M phase.Next,Immunoprecipitation (IP) experiments were used to verify the protein molecules with which TIGD1 might interact.And the results show that TIGD1 may be bound to Aurora kinase interacting protein 1 (AURKAIP1).Further,the Co-IP experiment confirmed the interaction between TIGD1 and AURKAIP1.AURKAIP1 is known to regulate the proteasomal degradation pathway of Aurora kinase A (AURKA),and AURKA is a mitotic regulatory protein that is closely associated with cell cycle progression.The paper further explored the effect of TIGD1 on AURKA protein levels,and the results show that TIGD1 knockdown obviously decreases the protein level of AURKA without affecting its mRNA level in Hep3B cells.In conclusion,TIGD 1 may affect cell cycle progression by regulating the posttranscriptional levels of AURKA in HCC cells,thus affecting the development of HCC.
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Taq DNA聚合酶作为实时荧光定量聚合酶链式反应(qPCR)技术的核心组分,其性能优劣直接影响qPCR技术的进一步发展。然而,野生型Taq DNA聚合酶的耐抑制剂性能差、延伸性能不足。为获得具有高性能的Taq DNA聚合酶,采用基因工程技术将双链DNA结合蛋白Sso7d或Sto7d融合在野生型Taq DNA聚合酶的N端或C端,构建了4个均可溶表达的改造体,再经过耐受性测试筛选较优的改造体,结果显示:改造体Taq-Sto的耐受性最高,其热稳定性不受影响,且在1 s/kbp的延伸条件下能成功扩增靶标,表明Taq-Sto具有增强的延伸性能,在TaqMan探针法qPCR体系中对腐殖酸、单宁酸、全血等抑制剂同样表现出良好的耐受性。EMSA实验发现:Taq-Sto对DNA模板的结合亲和力有所提高,有利于增强Taq-Sto对模板的竞争力;将Taq-Sto应用于非洲猪瘟病毒(ASFV)的TaqMan探针法qPCR检测,与商品化试剂相比,Taq-Sto具有更低的ASFV检出限,且在体积分数为2%~6%的猪粪便样本或猪肉样本中的检测灵敏度分别为100.0%和85.4%,说明Taq-Sto在直扩qPCR检测领域更具有优势。
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As the key component of quantitative real-time polymerase chain reaction (qPCR) technology,Taq DNA polymerase's performance directly affects the further development of qPCR technology.However,the wildtype Taq DNA polymerase has inadequate properties in inhibitor tolerance and elongation performance.To obtain Taq DNA polymerase with high performance,this study fused the double-stranded DNA-binding protein Sso7d or Sto7d to the N-terminal or C-terminal of wild-type Taq DNA polymerase by genetic engineering technology,which four soluble expression transformants were constructed,and then the better transformant was screened by tolerance test.The results show that the better transformant Taq-Sto has the highest tolerance,with no impact on its thermal stability,and the target can be successfully amplified by Taq-Sto under the extension condition of 1 s/kbp,indicating that Taq-Sto has enhanced extension performance.It also shows good tolerance to humic acid,tannic acid and whole blood in TaqMan qPCR system.EMSA experiment shows that the binding affinity of Taq-Sto to DNA template is improved,which is beneficial to enhancing the competitiveness of Taq-Sto to DNA template.Taq-Sto was applied to the TaqMan qPCR detection of African swine fever virus (ASFV).Compared with commercial reagents,Taq-Sto has lower detection limit of ASFV,and the detection sensitivity in 2%~6% (volume fraction) pig fecal samples or pork samples is 100.0% and 85.4%,respectively,indicating that Taq-Sto has more advantages in the field of direct qPCR detection.The results provide a reference for the development of DNA polymerase with better performance,which is conducive to further promoting the practical application of qPCR technology.
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系统研究了姜黄提取物、软骨提取物、葛根薏仁提取物单独及联合使用对膝骨关节炎大鼠软骨损伤的改善作用,主要从减少膝关节肿胀(炎症)、促进软骨细胞修复和关节基质修复方面,研究了3种提取物在大鼠膝骨关节炎中的协同效应。结果显示:姜黄提取物在抑制关节肿胀、改善软骨损伤方面有较明显的作用,具体表现在能较好地改善Ⅱ型胶原蛋白(Collagen Ⅱ)、基质金属蛋白酶3(MMP3)、软骨寡聚基质蛋白(COMP)、肿瘤坏死因子-α(TNF-α)及超氧化物歧化酶(SOD)的水平;软骨提取物主要通过改善MMP3、COMP、TNF-α、前列腺素E2(PGE2)及SOD水平起到明显改善关节炎病变的效果;葛根薏仁提取物能够提高Collagen Ⅱ及SOD水平,抑制MMP3、COMP、TNF-α和白细胞介素1β(IL-1β)的升高,从而改善大鼠膝关节病变程度;3种提取物的复合使用对大鼠膝关节软骨的修复作用最为突出,且对各生化指标的异常改变均有更佳的改善效果。由此可见,通过对姜黄提取物、软骨提取物及葛根薏仁提取物的比例优化,可开发出具有显著抗炎和修复软骨作用的功能性食品,为实现"健康中国2030"添砖加瓦。
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This paper studied the synergistic effects of turmeric extract,cartilage extract,Pueraria lobata and Coix(Coix lacryma-jobi) seed extract alone and the combination on the improvement of cartilage damage of rats with knee osteoarthritis.The synergistic effects of the three extracts in rat knee osteoarthritis were evaluated mainly by reducing knee swelling (inflammation),protecting chondrocyte and repairing joint cartilage.The results show that the turmeric extract has a more obvious effect in inhibiting joint swelling and improving cartilage damage,which is specifically manifested in the ability to better improve the levels of Collagen Ⅱ,matrix metalloproteinase 3 (MMP3),cartilage oligomeric matrix protein (COMP),tumor necrosis factor-alpha (TNF-α) and superoxide dismutase (SOD).The cartilage extract significantly improves the arthritic lesions by improving the levels of MMP3,COMP,TNF-α,prostaglandin E2 (PGE2) and SOD.Pueraria lobata and Coix seed extract improves the levels of Collagen Ⅱ and SOD,inhibits the elevation of MMP3,COMP,TNF-α and interleukin 1β (IL-1β),and improves cartilage damage of rats with knee osteoarthritis.The combined use of the three extracts exhibits better effects on the repair of rat knee cartilage.These data imply that by optimizing the ratio of turmeric extract,cartilage extract and Pueraria lobata and Coix seed extract,functional foods can be developed with significant anti-inflammatory and cartilage repairing effects and contribute to the realization of" Healthy China 2030".
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通过添加不同含量的茶多酚提取物修饰大豆分离蛋白制备水包油乳液,考察大豆分离蛋白乳液的界面张力、蛋白吸附比例、乳液粒径以及Zeta电位等性质变化,探究茶多酚对大豆分离蛋白乳液性质和界面蛋白置换的影响。实验结果表明:添加茶多酚后,大豆分离蛋白的界面张力升高;大豆分离蛋白溶液(1%,质量分数)按照9∶1(质量比)与大豆油混合后,经过高速剪切和超声制备成水包油乳液,添加茶多酚制备的乳液稳定性提高,与空白对照组相比,当茶多酚添加量为0.04%时,乳液平均粒径从1.702 μm显著下降至1.203 μm(P <0.05),乳液的蛋白吸附比例从9.22%显著上升至20.68%(P <0.05),Zeta电位绝对值从25.7 mV显著上升至27.1 mV(P <0.05);大豆分离蛋白在油-水界面上具有抗胆盐置换的特性,由茶多酚修饰的大豆分离蛋白更加难以被胆盐置换,这可能是添加茶多酚后大豆分离蛋白具有较强的静电相互作用以及较厚的界面层导致的。肠道中的脂质消化是界面过程,探究脂滴界面上蛋白与胆盐的置换反应对研究脂质代谢和食品精准设计具有指导作用。
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The soy protein isolate was modified by adding different concentrations of tea polyphenols extract to prepare the oil-in-water (O/W) emulsion.The interfacial tension,interfacial protein adsorption fraction,emulsion particle size and zeta potential were investigated to explore the effect of tea polyphenols on the properties of soy protein isolate emulsion and interfacial protein displacement.The results show that the interfacial tension of soy protein isolate is increased after the addition of tea polyphenols.When soy protein isolate (1%,mass concentration) and soy oil are prepared into O/W emulsion with 9∶1 mass ratio by high-speed shear and ultrasound,tea polyphenols addition can improve the emulsion stability.Compared to the blank control group,when the amount of tea polyphenols added is 0.04%,the particle size of emulsion decreases significantly from 1.702 μm to 1.203 μm (P <0.05),the protein adsorption fraction increases significantly from 9.22% to 20.68% (P <0.05),and the zeta potential increases significantly from 25.7 mV to 27.1 mV (P <0.05),respectively.Soy protein isolate shows resistance to bile salts displacement at the oil-water interface.In addition,the soy protein isolate modified by tea polyphenols is more difficult to be displaced by bile salts because of the strong electrostatic interaction and the thicker interface layer.Lipid digestion in intestine is an interfacial process.Exploring the interfacial displacement between protein and bile salts is beneficial to the study of lipid metabolism and food precise design.
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通过2,2-偶氮二异丁基脒二盐酸盐(AAPH)诱导建立人胚肾细胞(HEK293)氧化应激损伤模型,评价5种小麦蛋白源肽Leu-Tyr(LY)、Pro-Tyr(PY)、Tyr-Gln(YQ)、Ala-Pro-Ser-Tyr(APSY)和Arg-Gly-Gly-Tyr(RGGY)的抗氧化活性,然后利用量子化学计算和分子对接技术预测5种小麦蛋白源肽与2,2-联氮-二(3-乙基-苯并噻唑-6-磺酸)二铵盐(ABTS)结合的最优构型和结合作用,探讨小麦蛋白源肽发挥活性的分子机制。细胞试验结果表明:5种小麦蛋白源肽作用后,细胞死亡率显著下降到3.68%以下(P <0.05),并且能显著减少AAPH诱导的活性氧自由基(ROS)生成(P <0.05),使ROS含量趋于正常水平;5种小麦蛋白源肽均呈现出较好的总抗氧化能力和1,1-二苯基-2-三硝基苯肼(DPPH)自由基清除能力(P <0.05),RGGY的总抗氧化能力最强,活性值为(1.46 ± 0.08)mmol/L Trolox,其次是APSY、YQ、PY和LY;YQ的DPPH自由基清除能力最强,清除率为61.34% ± 2.24%,其次是APSY、RGGY、PY和LY。分子对接结果表明,5种小麦蛋白源肽的CDOCKER交互能量(-CIE)评分分别为13.304 9、13.397 3、13.412 1、16.768 5、16.268 3,均可以有效地与ABTS相互作用,主要通过与ABTS分子之间形成较强的氢键和疏水作用力来发挥抗氧化活性。
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The study firstly established oxidative stress injury model of human embryonic kidney cells (HEK293) by the induction of 2,2-azobis (2-methylpropionamidine) dihydrochloride (AAPH) to evaluate the antioxidant activity of five wheat protein-derived peptides Leu-Tyr (LY),Pro-Tyr (PY),Tyr-Gln (YQ),Ala-Pro-Ser-Tyr (APSY) and Arg-Gly-Gly-Tyr (RGGY).Then,it used quantum chemistry and molecular docking techniques to predict the optimal configuration and binding effect of five wheat protein-derived peptides combined with 2,2-azinobis- (3- ethylbenzthiazoline-6-sulphonate) (ABTS),and to explore the molecular mechanism of wheat protein-derived peptides.The results of cell test show that after the action of five wheat protein-derived peptides,the cell death rate significantly decreases to below 3.68% (P <0.05),and the generation of reactive oxygen species (ROS) induced by AAPH was significantly reduced (P <0.05),making the ROS content tend to normal levels.All five wheat proteinderived peptides show good total antioxidant capacity and free radical scavenging capacity of 1,1-Diphenyl-2- picrylhydrazyl (DPPH) (P <0.05).RGGY shows the strongest total antioxidant capacity,with an activity value of(1.46 ± 0.08) mmol/L Trolox,followed by APSY,YQ,PY and LY.The DPPH free radical scavenging ability of YQ is the strongest,with a scavenging rate of 61.34% ± 2.24%,followed by APSY,RGGY,PY and LY.The results of molecular docking show that the CDOCKER interaction energy (-CIE) scores of the five wheat protein-derived peptides are 13.304 9,13.397 3,13.412 1,16.768 5 and 16.268 3,respectively,which can effectively interact with ABTS,mainly through the formation of strong hydrogen bonds and hydrophobic forces between ABTS molecules to exert antioxidant activity.
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多目标识别及六自由度(6-DoF)位姿估计是实现物料无序堆放状态下机器人自动分拣的关键。近年来,基于深度神经网络的方法在目标识别及位姿估计领域受到广泛关注,但此类方法依赖大量训练样本,而样本的采集及标注费时费力,限制了其实用性。其次,当成像条件差、目标相互遮挡时,现有位姿估计方法无法保证结果的可靠性,进而导致抓取失败。为此,文中提出了一种基于合成数据样本的目标识别、分割及位姿估计方法。首先,以目标对象的3维(3D)几何模型为基础,利用3D图形编程工具生成虚拟场景的多视角RGB-D合成图像,并对生成的RGB图像及深度图像分别进行风格迁移和噪声增强,从而提高合成数据的真实感,以适应真实场景的检测需要;接着,利用合成数据集训练YOLOv7-mask实例分割模型,运用真实数据进行测试,结果验证了该方法的有效性;然后,以分割结果为基础,基于ES6D目标位姿估计模型,提出了一种在线姿态评估方法,以自动滤除严重失真的估计结果;最后,采用基于主动视觉的位姿估计校正策略,引导机械臂运动到新的视角重新检测,以解决因遮挡而导致位姿估计偏差的问题。在自行搭建的6自由度工业机器人视觉分拣系统上进行了实验,结果表明,文中提出的方法能较好地适应复杂环境下工件的识别与6-DoF姿态估计要求。
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Multi-object recognition and 6-DoF (degree of freedom) pose estimation are the key to achieve automatic sorting of robots in the state of unordered stacking of materials.In recent years,methods based on deep neural networks have received much attention in the multi-object recognition and 6-DoF pose estimation fields.Such methods rely on a large number of training samples,however,the collection and labeling of samples is time-consuming and laborious,which limits its application.In addition,when the imaging conditions are poor and the targets are occluded by each other,the existing pose estimation methods cannot guarantee the reliability of the results,resulting in grasping failures.To this end,this paper presented a method for target recognition,segmentation and pose estimation based on synthetic data samples.Firstly,multi-view RGB-D synthetic images of virtual scenes were generated using 3D graphics programming tools based on the 3D geometric models of the target objects,and then style transfer and noise enhancement was performed,respectively,on the generated RGB images and the depth images to improve their realism,so that they are suited for the detection in real scenes.Next,the YOLOv7-mask instance segmentation model was trained with synthetic datasets and tested by real data.The results demonstrate the effectiveness of the proposed method.Secondly,the ES6D model was utilized to estimate target poses based on the segmentation results,and an online posture evaluation method was proposed to automatically filter out severely distorted estimation results.Finally,a pose estimation correction strategy based on active vision technique was proposed to guide the robot arm to move to a new viewpoint for re-detection,which can effectively solve the problem of pose estimation deviation caused by occlusion.The above methods have been verified on a self-built 6-DoF industrial robot vision sorting system.The experimental results show that the proposed algorithm can well meet the requirements of recognition and 6-DoF posture estimation of common workpieces in complex environments.
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目前机器人已在工业生产制造中得到广泛的应用,但由于机器人系统中关节摩擦等因素的影响,机器人的轨迹跟踪精度难以满足高精度生产的需求。为减少机械结构中非线性摩擦因素和系统中未建模干扰等因素对机器人运行稳定性和加工精度的影响,文中提出了一种速度模式下的摩擦补偿控制算法。首先,基于傅里叶级数和5次多项式混合的方式设计最优激励轨迹,通过最小二乘法完成动力学参数的预辨识,并利用Levenberg-Marquardt法对预辨识结果进行迭代寻优,从而建立更为精确的机器人动力学模型;然后,基于李雅普诺夫方法设计机器人轨迹跟踪控制算法,将最速离散跟踪微分器中采集的关节角度输入所设计的轨迹跟踪控制算法中,得到实时的关节速度补偿值,将补偿值实时输入机器人中实现摩擦补偿控制;最后,以六自由度串联机器人为实验对象,对所设计的摩擦补偿控制算法进行实验验证。结果表明,相对于摩擦补偿前,机器人的末端轨迹跟踪精度提升约35%,从而验证了文中所提算法在机器人摩擦补偿领域的有效性。
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Currently,robots are extensively utilized in industrial manufacturing.However,due to the influence of joint friction and other factors in the robot system,the robot trajectory tracking accuracy is difficult to meet the requirements of high-precision production.In this study,a friction compensation control algorithm in speed mode was proposed to mitigate the impact of non-linear friction factors in the mechanical structure and unmodelled disturbances on the robot's operational stability and machining precision.The optimal excitation trajectory was designed by a combination of Fourier series and fifth-order polynomial.Dynamic parameters were then preidentified by the least squares method and iteratively optimized through the Levenberg-Marquardt method to establish a more precise robot dynamic model.Subsequently,the Lyapunov method was adopted to design the trajectory tracking control algorithm,and the joint angles collected in the steepest discrete tracking differentiator were fed into the control algorithm to calculate the real-time compensation.The compensation value was then applied in the robot,which effectively achieving friction compensation.The proposed algorithm was validated by employing a six-degree-of-freedom serial robot as an experimental subject.The results demonstrate that the trajectory tracking error is reduced by approximately 35%,as comparing with that under the non-compensation conditions,which confirms the efficacy of the algorithm in the realm of robot friction compensation.
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液压驱动的重型机械臂被广泛应用于工程机械和矿山机械,对其进行自动控制在行业内具有迫切的需求。然而,液压系统的强参数不确定性和难以建模的动态等因素的影响,给其自动控制带来了一定的挑战。文中以某锚杆钻车为例,研究了一类重型液压机械臂驱动液压缸的位置跟踪控制问题,提出了一种模型前馈补偿自抗扰控制器。为解决重载下变负荷、死区、参数不确定以及摩擦等非线性因素带来的控制难题,采取模型前馈与自抗扰反馈相结合的控制方法,将重型液压机械臂的机构动力学模型和比例阀控液压缸模型相结合,建立了系统的机理模型,然后基于系统的机理模型,构建了控制器的前馈补偿部分;设计了扩张状态观测器对系统的未建模因素进行实时观测,再加上基于状态误差的反馈调整构成了自抗扰控制器。最后在实际的重型液压机械臂上进行了实验研究,结果表明:基于模型前馈补偿的自抗扰控制器相比于PID控制器,具有更小的滞后和跟踪误差,整体跟踪精度比PID控制器提升了63.5%,说明所设计的控制器可以很好地克服液压系统的非线性因素的不利影响,比PID控制器具有更高的鲁棒性,因此所设计的控制方法更适用于此类重型液压机械臂的位置跟踪控制。
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Hydraulically-driven heavy-duty manipulator arms are widely used in construction and mining machinery,and there is an urgent need for its automatic control in the industry.However,the strong parametric uncertainties and difficult-to-model dynamics of the hydraulic system and other factors bring certain challenges to its automatic control.This paper studied the position tracking control problem of a class of heavy-duty hydraulic manipulator arm driven hydraulic cylinders by taking an anchor drilling truck as an example,and proposed a model feedforward compensation active disturbance rejection controller.To solve the control problems caused by nonlinear factors such as variable load,dead zone,parametric uncertainties and friction under heavy loads,the study adopted the control method of combining model feedforward and active disturbance rejection feedback,and established the mechanism model of the system by combining the mechanism dynamics model of the heavy-duty hydraulic manipulator arm and the model of proportional valve-controlled hydraulic cylinders.Then based on the mechanism model of the system,it constructed the feedforward compensation part of the controller,and designed an extended state observer to observe the unmodeled factors of the system in real time,and the active disturbance rejection controller was constituted together with the feedback adjustments based on the state error.The experimental studies were carried out on a real heavy-duty hydraulic manipulator arm,and the results show that the model feedforward compensation active disturbance rejection controller has smaller hysteresis and tracking error than PID controller,and the overall tracking accuracy is improved by 63.5% compared with that of PID controller.This indicates that the designed controller can overcome the adverse effects of the nonlinear factors of the hydraulic system very well,and it has a higher robustness than the PID controller.Therefore,the designed control method is more suitable for the position tracking control of this kind of heavy-duty hydraulic manipulator arm.
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斜轴式轴向柱塞马达内部噪声源距离较近,如马达配流盘进、出油口间的距离为38 mm,且马达噪声源存在同频及倍频现象。斜轴式马达内部密集复杂的噪声源,导致频谱分析方法难以准确识别同频及倍频信号,传统声强测量的最高分辨率为50 mm,无法满足马达内部噪声源的辨识精度要求。针对传统方法难以准确辨识马达噪声源的问题,文中提出了一种基于压缩感知的声强测量方法,将压缩感知理论运用于声强云图高精度重构中,获取马达高分辨率的声强重构图像。首先,通过对斜轴式马达进行噪声辐射仿真分析,获取其外表面声场特性;然后,以马达外表面声强云图为先验信息,设计应用于马达声场的压缩感知框架,获取高精度重构马达声强云图;最后,通过马达传统声强测量与压缩感知声强测量的对比实验验证压缩感知理论对于提高马达噪声源辨识精度的可行性。结果表明,基于压缩感知的声强测量方法将马达噪声源辨识尺度从原来的70 mm提升至30 mm,提高了马达噪声源的辨识精度,实现了马达噪声源的高精度定位。
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The internal noise sources of the bent-axis piston motor are close in distance.For example,the distance between the inlet and outlet of the motor valve plate is 38 mm,and the noise sources have the same frequency and multiple frequency phenomenon.The dense and complex noise sources in the bent-axis motor cause difficulties for the spectrum analysis method to accurately identify the same frequency and multiple frequency signals.The maximum resolution of traditional sound intensity measurement is 50 mm,which cannot meet the requirement of identification accuracy of motor internal noise source.Aiming at the problem that the traditional methods are difficult to identify the motor noise sources accurately,this paper proposed a sound intensity measurement method based on compressed sensing.The compressed sensing theory was applied to the high-precision reconstruction of sound intensity image to obtain the high-resolution sound intensity reconstruction image of the motor.Firstly,the noise radiation simulation of the bent-axis motor was carried out to obtain the characteristics of its external surface sound field.Then,based on the sound intensity image for the motor,a compressed sensing frame applied to the motor sound field was designed to obtain the sound intensity cloud image of the motor with high precision.Finally,the feasibility of the compressed sensing theory to improve the identification accuracy of motor noise source was verified by comparing the traditional acoustic intensity measurement with the compressed sensing acoustic intensity measurement.The results show that the identification scale of motor noise sources are improved from 70 mm to 30 mm by the sound intensity measurement method based on compressed sensing,which improves the accuracy of motor noise sources identification and realizes the high precision location of motor noise sources.
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为进一步提高摆线针轮减速机的传动效率,对减速机传动效率的影响规律进行了深入研究,提出了考虑设计参数与工况参数变化的摆线针轮减速机传动效率计算模型,并对参数进行了优化。首先,考虑摩擦力和啮合齿隙,建立了摆线针轮传动机构的多齿承载接触分析模型,计算了摆线针齿啮合力与载荷分布规律;然后,考虑摆线针轮减速机的啮合损耗、输出损耗、轴承损耗、润滑损耗和密封损耗,提出了摆线针轮减速机传动效率计算模型,并分析了设计参数和工况参数对摆线针轮减速机传动效率的影响规律。研究表明,在考虑摩擦受力的情况下,转速、负载、针齿销半径、针齿分布圆半径、偏心距、针齿套半径是影响传动效率的主要参数,针齿销数、柱销分布圆半径、柱销半径和摆线轮齿宽次之。最后,以齿轮强度、齿轮宽度、齿廓形状、齿间间隙和承载能力作为参数优化范围,将效率和体积作为目标对设计参数进行多目标优化分析,得到最优参数解,进而获得了更小体积、更高传动效率的摆线针轮减速机。
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In order to further improve the transmission efficiency of the cycloidal pinwheel reducer,this study conducted in-depth research on the influence of the reducer transmission efficiency.It proposed a calculation model for the transmission efficiency of the cycloidal pinwheel reducer that takes into account changes in design parameters and working condition parameters and optimized the parameters.Firstly,considering the friction force and meshing backlash,the study established a multi-tooth load-bearing contact analysis model of the cycloid pinwheel transmission mechanism,and calculate the meshing force and load distribution pattern of the cycloid pinwheel gear.Then,considering the engagement loss,output loss,bearing loss,lubrication loss and sealing loss,this paper proposed a calculation model for the transmission efficiency of the cycloidal pinwheel reducer,and analyzed the influence of the design parameters and working condition parameters on the transmission efficiency of the cycloidal pinwheel reducer.Research shows that,taking frictional stress into account,rotation speed,load,pin tooth pin radius,pin tooth distribution circle radius,eccentricity,and pin tooth sleeve radius are the main parameters that affect transmission efficiency,followed by the number of pin teeth,pin distribution circle radius,pin radius and cycloid tooth width.Finally,the optimal parameter solution was obtained through a multi-objective optimization analysis of the design parameters with gear strength,gear width,tooth profile shape,inter-tooth clearance and load-bearing capacity as the parameter optimization range,and transmission efficiency and volume as the goals.And then a smaller volume and more efficient cycloidal pinwheel reducer was obtained.
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自润滑关节轴承在服役过程中,衬垫的磨损导致自润滑关节轴承内外圈之间产生间隙,自润滑运动副间隙的存在加速了内外圈之间的碰撞以及衬垫的进一步磨损,对自润滑关节轴承的动力学特性产生较大的影响。此外,衬垫的磨损还会导致各构件非线性特性的恶化,降低自润滑关节轴承的稳定性。为研究织物衬垫磨损对自润滑关节轴承动力学响应的影响,文中建立了带间隙的自润滑关节轴承运动副矢量模型。首先,通过修正Lankarani-Nikravesh(L-N)法向接触力模型和改进的库仑摩擦力模型,对内外圈间隙处的碰撞力进行建模;然后,基于牛顿第二定律建立了含间隙的刚柔耦合动力学方程;最后,分析讨论不同织物衬垫磨损量和不同摩擦因数条件下含间隙的自润滑关节轴承传动系统的动力学特性,并利用相图和Poincare映射图分析了自润滑关节轴承的非线性特性。结果表明:随着织物衬垫磨损量的增加,自润滑关节轴承内圈和外圈的动力学行为表现出非线性特性;衬垫磨损量一定时,随着衬垫摩擦因数的增加,系统稳定性得到提高,抑制了混沌现象的发生。
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In the service process of self-lubricating joint bearings,the wear of the liner leads to the gap between the inner and outer rings of the self-lubricating joint bearings.The existence of the clearance of the self-lubricating remote pair accelerates the collision between the inner and outer rings and further wear of the liner,which has a great impact on the dynamic characteristics of the self-lubricating joint bearings.In addition,the wear of the liner will also lead to the deterioration of the nonlinear characteristics of each component and reduce the stability of selflubricating joint bearings.In order to study the effects of the wear of the self-lubricating liner on the dynamic response of the self-lubricating joint bearing,this study established the kinematic subvector model of selflubricating joint bearing with clearance.Firstly,it modeled the collision force at the gap between the inner and outer rings by modifying the Lankarani-Nikravesh (L-N) normal contact force model and improving the Coulomb friction force model.Then,based on Newton's second law,it established the rigid-flexible coupling dynamic equation with gap.Finally,it analyzed the dynamic characteristics of the drive system of the self-lubricating knuckle bearing with clearance under different wear amount and friction factor.And it also analyzed the nonlinear characteristics of the self-lubricating knuckle bearing by using phase diagram and Poincare mapping diagram.The results show that the dynamic behavior of the inner and outer rings of the self-lubricating joint bearing exhibits nonlinear characteristics with the increase of the wear amount of the fabric liner.When the wear amount is certain,the stability of the system is improved with the increase of the friction factor of the liner,and the occurrence of chaos is suppressed.
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针对路基段高铁行车安全分析常将地基土视作具有确定性参数的介质的问题,文中基于随机场理论,将地基土视为具有纵向一致性的三维介质,建立了盾构下穿既有高铁的数值模型,并基于数论选点方法模拟地基土横截面的参数随机性。为更进一步研究盾构下穿高速铁路对高铁行车安全性的影响,文中建立了31自由度的高铁列车模型,结合Fluent 3D流体仿真软件和动网格技术,获得了高速列车的气动荷载时程曲线。基于概率密度演化理论分析了高铁列车以300、350和400 km/h的速度交会时的脱轨系数及其概率密度演化信息。结果表明:随机场的存在使得车辆的轮重减载率和脱轨系数具有一定的概率分布范围;在气动荷载和隧道下穿引起的既有高铁线路基变形影响下,垂向轮轨力曲线有明显的波动情况;轮重减载率最大值出现在地表沉降最大值两侧的下降段;垂向气动荷载大于横向气动荷载;随着车速的增加,轮重减载率及脱轨系数的各上限均在逐渐增大,为保证高铁交会行车的安全性,建议在盾构下穿既有线地段的高铁列车运行速度应不超过300 km/h。
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In view of the problem that the subgrade soil is often regarded as a medium with deterministic parameters in the traffic safety analysis of high-speed railway in subgrade section.In this paper,based on the stochastic field theory,subgrade soil was regarded as a three-dimensional medium with longitudinal uniformity,and a numerical model was established for a shield tunnel penetrating below an existing high-speed railway line.The parameter randomness of the subgrade soil cross section was simulated based on the number theory point selection method.In order to further explore the impact of a penetration shield tunnel on the safety of the existing high-speed railway,a 31- DOF vehicle model was established in this paper.Combined with the Fluent 3D fluid simulation software and dynamic grid technology,the aerodynamic load time history curve of high-speed train was obtained,and the derailment coefficient and probability density evolution information of trains at speeds of 300,350 and 400 km/h were analyzed based on the probability density evolution theory.The results show that the existence of stochastic field makes the wheel weight reduction rate and derailment coefficient present a certain probability distribution range.The vertical wheel-rail force curve fluctuates obviously under the influence of the aerodynamic load and the subgrade deformation caused by the tunnel penetration.The maximum load reduction rate of wheel weight appears in the descending section on both sides of the maximum surface settlement.The vertical aerodynamic load is greater than the transverse aerodynamic load.With the increase of vehicle speed,the upper limits of wheel weight reduction rate and derailment coefficient are gradually increasing.In order to ensure the safety of intersecting trains,it is recommended that the running speed of high-speed trains under the shield tunneling should not exceed 300 km/h.
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为提高自动驾驶车辆在超高速公路行驶的安全性,提出了一种换道轨迹规划策略。首先,采用5次多项式生成一般变道轨迹簇,以车辆动力学极限和周围交通车辆为约束,将轨迹规划问题量化为求解换道行为持续时间;接着,考虑车辆动力学约束,建立了车辆动力学模型和Brush轮胎模型,基于所建立汽车模型的轮胎侧向力数据求解轮胎侧偏刚度,辅以魔术轮胎模型,验证所求轮胎侧偏刚度;然后,引入质心侧偏角-横摆角速度相平面,得到高速车辆安全驾驶包络线,并给定多组车速和附着系数进行CarSim仿真训练,确定满足车辆动力学约束的最短换道时间;最后,考虑与周围交通车辆的避撞约束,分析3种典型的换道场景,基于单障碍车的位置,确定满足避撞要求的最短与最长换道持续时间,建立满足安全换道要求的换道持续时间阈值模型。经多参数安全换道域检验,所建立的车辆安全换道持续时间边界模型能够在给定参数下求解出安全可行的换道轨迹,为超高速公路换道行为提供轨迹参考,提高超高速公路换道行为的安全性。
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To improve the driving safety of autonomous vehicles on superhighways,this paper proposed a lanechanging trajectory planning strategy.Firstly,five polynomials were used to generate general lane-changing trajectory clusters,and the trajectory planning problem was quantified as the duration of solving lane-changing behavior with the limit of vehicle dynamics and surrounding traffic vehicles.Then,considering the constraints of vehicle dynamics,the vehicle dynamics model and Brush tire model were established.Based on the tire lateral force data of the established vehicle model,the tire lateral stiffness was solved,and the magic tire model was used to verify the tire lateral stiffness.Next,the phase plane of sideslip angle and yaw rate was introduced to obtain the safe driving envelope of high-speed vehicle.CarSim simulation training was carried out on given multiple groups of vehicle speeds and adhesion coefficients to determine the shortest lane-changing time that meets the vehicle dynamics constraints.Finally,considering the collision avoidance constraints with surrounding traffic vehicles,three typical lane-changing scenarios were analyzed.The shortest and longest lane-changing durations satisfying the collision avoidance requirements were determined based on the position of single obstacle vehicle,and the threshold model of lane-changing duration satisfying the safe lane-changing requirements was established.The multi-parameter safety lane-changing domain test shows that the established vehicle safety lane-changing duration boundary model can solve the safe and feasible lane-changing trajectory under the given parameters,provide trajectory reference for the superhighway lane-changing behavior,and improve the safety of the superhighway lanechanging behavior.
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为探索行人过街事件网联环境下平视显示预警系统在不同天气条件下对驾驶行为的影响,以论证预警系统的有效性。文中首先设计基线条件(Baseline)、低头显示(HDD)、平视显示(HUD)3种预警系统,依托驾驶模拟平台开发晴天和雾天天气条件下城市道路网联场景,通过实验测试提取驾驶行为参数;然后,从微观层面刻画行人过街事件网联HUD预警系统作用下驾驶行为的整个空间变化过程,分析预警系统和天气状况两种因素对驾驶行为的作用规律,构建包含避险阶段和恢复阶段的驾驶行为影响模式,提出了反映避险阶段安全水平、恢复阶段恢复水平以及全过程稳定水平等3个层面的综合指标体系,包括首次制动距离、最小冲突距离、恢复稳定时间、速度恢复量、最大减速度和最大加速度;最后,量化不同预警系统(Baseline/HDD/HUD)、天气状况(晴天/雾天)以及两因素间交互作用对驾驶行为的影响。结果表明:行人过街网联HUD预警系统对驾驶人在避险阶段和恢复阶段中的驾驶行为存在显著性作用,显著提高避险阶段驾驶行为的安全水平,同时对恢复阶段恢复效率具有明显的提升作用,也显著影响全过程运行特性的稳定水平;在雾天条件下行人过街网联HUD预警系统表现出更为明显的优势。
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In order to demonstrate the effectiveness of the warning system,this study explored the influence of the head up display warning system on driving behavior under different weather conditions in the connected environment for pedestrian crossing events.Firstly,this paper designed three warning systems:baseline,head down display (HDD),and head up display (HUD).Based on the driving simulation platform,it developed connected scenarios of urban roads under clear and foggy weather conditions and extracted driving behavior parameters through experimental testing.Then,from the micro level,the paper described the whole spatial change process of driving behavior under the action of connected HUD warning system for pedestrian crossing events,analyzed the influence rules of the warning systems and weather conditions on driving behavior,and constructed the influence model of driving behavior including risk avoidance stage and recovery stage.Next,a comprehensive index system was proposed to reflect the safety level at the risk avoidance stage,the recovery level at the recovery stage and the stability level of the whole process,including the first braking distance,the minimum conflict distance,the recovery stabilization time,the recovery amount of velocity,the maximum deceleration and the maximum acceleration.Finally,it quantified the effects of different warning systems (Baseline/HDD/HUD),weather conditions (clear weather/foggy weather) and the interaction between the two factors on driving behavior.Research shows that the connected HUD warning system for pedestrian crossing events has a significant effect on drivers' driving behavior in the risk avoidance and recovery stage,and it significantly improves the safety level of driving behavior in the risk avoidance stage.At the same time,it has a significant improvement effect on the recovery efficiency during the recovery stage,and also significantly affects the stability level of the operational characteristics throughout the whole process.The connected HUD warning system for pedestrian crossing events shows more obvious advantages under foggy conditions.
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驾驶风格是驾驶行为的外在表达,激进风格的驾驶员容易进行更为频繁的危险驾驶操作,加剧车辆之间的交互作用,影响换道安全。在换道动作执行前识别驾驶员的驾驶风格,可以通过个性化预警信息有效约束驾驶员行为。文中提出了一种网联环境下考虑换道博弈的驾驶风格在线识别方法SHAP-XGBoost,以期在换道意图期间完成驾驶风格的识别。首先,将换道意图期间换道车辆及其周围车辆的个体行为和博弈行为的波动程度作为输入特征变量,通过相关性分析、主成分分析以及4种不同聚类方法对驾驶风格进行标记;然后,利用提出的SHAP-XGBoost模型选择关键特征,以训练驾驶风格识别模型,并通过滑动窗口完成在线识别;最后,采用HighD数据进行实验。结果表明:与基于质心距离、连通性、密度分布的聚类方法相比,基于图论原理的谱聚类可以更好地根据输入特征变量的形态标记驾驶风格;利用SHAP-XGBoost模型及14个关键特征进行驾驶风格识别,可以在不损失准确率的同时提高在线识别效率,驾驶风格识别准确率高达99%;同时将个体特征和博弈特征作为模型的输入时,可以提升驾驶风格标记和识别的准确率。此研究成果可为个性化换道决策和预警提供支持。
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Driving style is the external expression of driving behavior.Drivers with aggressive style tend to engage in more frequent risky driving operations,intensifying interactions between vehicles and affecting lane-changing safety.Identifying a driver's driving style before executing a lane-changing can effectively constrain driver's behavior through personalized warning information.This paper proposed the SHAP-XGBoost method,which considers lane-changing game in a connected environment,aiming to achieve the real-time recognition of driving styles during the lane-changing intention phase.Firstly,the fluctuation degree of individual behavior and gaming behavior during the lane-changing intention was used as input feature variables,and the driving style was marked by correlation analysis,principal component analysis,and four different clustering methods.Next,the proposed SHAP-XGBoost model was used to select key features for training the driving style recognition model,and online recognition was completed through a sliding window.Finally,experiments were conducted using the HighD dataset.Results show that:compared with clustering methods based on centroid distance,connectivity and density distribution,spectral clustering based on graph theory principles can better label driving styles based on the morphology of the input feature variables;using the proposed SHAP-XGBoost model with 14 key features for driving style recognition can improve online recognition efficiency without loss of accuracy,and the driving style recognition accuracy is up to 99%;simultaneously incorporating individual features and gaming features as inputs to the model can improve the accuracy of driving style labeling and recognition.The research results can be used to support personalized lane-changing decisions and early warnings.
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为了获得公交危险驾驶状态的空间分布特征,采用空间自相关性分析方法,识别危险驾驶状态的空间集聚性,确定危险驾驶状态热点路段,并对显著性影响因素进行分析。首先,采集4个季度各1周公交车辆卫星定位数据样本,修复重复数据、异常数据和缺失数据,并以公交站点为节点划分空间区段,对每个区段进行编号;接着,将速度过快、急加速、急减速和急转弯确定为危险驾驶状态,参照车辆运动学特性获得4种危险驾驶状态阈值,并计算4种危险驾驶状态的统计学指标和全局莫兰指数,结果表明,公交车辆危险驾驶状态具有空间集聚性(空间随机分布概率p <0.01,标准差得分值Z >2.58),速度过快状态(全局莫兰指数为0.731)的空间集聚性最为显著;然后,分别对4种危险驾驶状态进行局部空间自相关性分析,绘制了90%、95%和99%置信度下的莫兰散点图和Lisa集聚图,结合城市地图,获得危险驾驶状态的热点路段;最后,选取路段长度、车道数、平直度等9个指标,对比分析了OLS模型、SLE模型、SEM模型和SDM模型的拟合优度,采用SDM模型获得4种危险驾驶状态的显著性影响因素。文中研究结果可为公交车辆危险驾驶状态空间识别、精细化安全运行管理提供理论依据。
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In order to obtain the spatial distributing characteristics of hazardous bus driving status,this paper identified the spatial clustering through spatial autocorrelation analysis,determined the hot spots,and analyzed the significant influencing factors.Firstly,the study collected position system data samples of the urban buses for one week in each of the four quarters and modified the duplicate,abnormal and missing data.Bus stops were used as nodes to divide spatial spots,and every spot was numbered.Over speed,urgent acceleration,urgent deceleration and sharp turn were identified as hazardous driving status.The four conditions thresholds were obtained according to the kinematic characteristics of vehicles.The study calculated statistical indicators and global Moran's Ig of four conditions.The results show that hazardous driving status are spatially clustered (probability of a spatial random distribution p <0.01,standard deviation score Z >2.58).Over speed has most significant characteristic of spatial clustering (Ig = 0.731).The study performed local spatial autocorrelation analysis for the four conditions.According to the analysis,local Moran' s I scatter plots and LISA clustering plots are plotted at 90%,95% and 99% confidence levels.The hazardous hot spots of urban buses were obtained combining with city maps.Finally,the study selected 9 factors such as road length,number of lanes and straightness to formulate models.The compare and analysis were performed to get the fitting goodness of OLS,SLE,SEM and SDM model.The SDM model was used to obtain the significant influencing factors for 4 dangerous driving states.The results can provide a theoretical basis for supervising the safety operation and identifying the hazardous driving status of urban buses in spatial perspective.
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目的通过测量正常人群颈椎解剖学参数,为设计新型双螺纹椎弓根螺钉提供理论依据。方法纳入100名健康人群,完善颈椎CT扫描,在CT片上分别测量C_(3~7)的双侧椎弓根螺钉进钉路径长度(包括椎体内长度、椎弓根长度、椎板长度,作为椎弓根螺钉长度设计参考)、进钉外展角和椎弓根峡部的宽度和高度(作为椎弓根螺钉直径设计参考)。计算各测量结果的均值及四分位数。结果纳入成年健康志愿者100人的基本信息,包括身高、年龄,体重,合并疾病,其中男54例,女46例,平均年龄35.95岁。从C_(3~7),各参数左右两侧对比,差异无统计学意义(P>0.05),男女间对比,差异无统计学意义(P>0.05)下颈椎椎弓根螺钉进钉路径椎体平均长度(15.85±1.20)~(19.40±1.50)mm;椎弓根平均长度(5.42±1.06)~(6.03±0.84)mm;椎板平均长度(9.52±1.15)~(10.33±1.58)mm。进钉外展角平均值范围(39.82±2.53)°~(42.56±2.50)°;椎弓根峡部宽度平均值(5.84±0.87)~(7.10±1.05)mm;椎弓根峡部高度平均值(6.71±1.10)~(8.26±1.22)mm。结论通过对正常人群颈椎C_3~C_7椎弓根螺钉进钉相关解剖参数的测量,为设计新型双螺纹颈椎椎弓根螺钉提供了理论依据。
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Objective To provide theoretical basis for the design of new double threaded pedicle screws,by measuring the anatomical parameters of cervical vertebrae in normal people.Methods A total of 100 healthy individuals were collected and the cervical spine CT scan were completed.The length of bilateral pedicle screw insertion path (including intra-vertebral length,pedicle length,and vertebral plate length,as reference for pedicle screw length design),insertion abduction angle,and width and height of pedicle isthmus(as reference for pedicle screw diameter design) of C_(3~7) on CT scan.The mean value and quartile of each measurement result were calculated.Results Basic information of 100 adult healthy volunteers,including height,age,weight,and comorbidities,including 54 males and 46 females,with an average age of 35.95 years were recorded.From the CT scan of C_(3~7),there was no statistical difference between the left and right sides of each parameter (P>0.05).There was no statistical difference in male and female (P>0.05).The average length of the vertebral body in the lower cervical pedicle screw insertion path was (15.85±1.20)~(19.40±1.50) mm.The average length of the pedicle was (5.42±1.06)~(6.03±0.84) mm.The average length of the vertebral lamina was (9.52±1.15)~(10.33±1.58) mm.The average range of nail insertion and abduction angle was(39.82±2.53) °~(42.56±2.50) °.The average width of the pedicle isthmus was (5.84±0.87)~(7.10±1.05) mm.The average height of the pedicle isthmus was (6.71±1.10)~(8.26±1.22) mm.Conclusions The measurement of the anatomical parameters related to C_3~C_7 pedicle screw fixation in normal people provides theoretical basis for the design of a new type of double-threaded pedicle screw.
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目的测量C_(2/3)经关节突经椎弓根螺钉相关影像学指标,并分析该置钉技术的可行性。方法收集120例全颈椎CT薄层扫描数据,其中男性75例,女性45例。设定C_(2/3)经关节突经椎弓根螺钉的进钉点,即进钉点在枢椎侧块的水平中线与中外1/3垂线交点处,螺钉自枢椎侧块穿C_(2/3)关节突关节、C3侧块止于C3椎弓根下缘。测量C_(2/3)经关节突经椎弓根螺钉相关影像学数据,包括C3椎弓根宽度与高度,螺钉通道长度,内倾角度,头倾角度,最狭窄处宽度。并分析各项测量结果之间的关系。结果C3椎弓根平均宽度5.48 mm,平均高度6.82 mm,螺钉通道平均长度18.68 mm,平均内倾角度20.46°,平均头倾角度50.1°,最狭窄处平均宽度2.80 mm。C3椎弓根宽度与高度呈正相关(P=0.000),螺钉通道长度与C3椎弓根宽度、高度呈正相关(P=0.000;P=0.000),螺钉通道最狭窄处宽度与C3椎弓根宽度、高度呈正相关(P=0.000;P=0.000)。240例置钉测量数据中,如使用3.5 mm直径螺钉,均可完成置钉,C_(2/3)经关节突经椎弓根螺钉适用于所有患者。结论C_(2/3)经关节突经椎弓根螺钉在解剖学上是可行的,可作为上颈椎后路钉棒内固定补充的置钉技术。
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Objective To measure the imaging indexes of C_(2/3) transarticular transpedicular screw,and analyze the feasibility of this screw placement technique.Methods The CT data of 120 thin slice CT scan were collected,including 75 males and 45 females.The entry point of the C_(2/3) transarticular transpedicular screw was set,that is,the entry point was at the intersection of the horizontal midline and the mid-lateral 1/3 vertical line of the lateral mass of the axis.The screw passed through the facet joint of C_(2/3) and the C3 lateral mass,from the lateral mass of the axis,and ended at the inferior edge of the pedicle of C3.The imaging data of C_(2/3) transarticular transpedicular screw were measured,including C3 pedicle width and height,screw channel length,introversion angle,head tilt angle and the narrowest width.The relationship between the measurement results was analyzed.Results The average width of C3 pedicle was 5.48mm,the average height was 6.82 mm,the average screw channel length was 18.68mm,the average introversion angle of screw channel was 20.46 °,the average head tilt angle was 50.1°,and the average width of the narrowest part was 2.80 mm.There was a positive correlation between C3 pedicle width and height (P=0.000).The length of screw channel was positively correlated with C3 pedicle width and height (P=0.000;P=0.000).The width of the narrowest part of screw channel was positively correlated with C3 pedicle width and height (P=0.000;P=0.000).In the measurement data of 240 cases,the screw placement could be completed if 3.5 mm diameter screws were used,and the screw was suitable for all patients.Conclusions C_(2/3) transarticular transpedicular screw is anatomically feasible and can be used as a supplementary technique for posterior screw rod internal fixation of upper cervical spine.
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目的数字化测量髋臼后柱壁安全置钉相关参数,为临床治疗后壁或/和后柱骨折置钉提供参考。方法经软件Mimics20.0重建100例正常成人髋骨三维模型。将髋臼后壁分为累及臼顶的高位后壁区与未累及臼顶的低位后壁区,切割髋臼高位后壁区得到断面M、D、E和N,切割低位髋臼后壁区形成断面F、G、H、I和J。在断面上测量进钉角度和进钉长度。结果在断面M、D、E和N上距臼缘5.0 mm的进钉点,男女螺钉最大安全进钉角度分别不应超过80°、70°、60°与50°,男女进钉长度分别不应超过40.0与35.0 mm。在断面F、G、H、I和J上,男女距臼缘5.0、10.0、20.0与30.0 mm的进钉角度应分别小于50°、60°、80°和90°。断面F至J中,男性进钉点螺钉长度应分别小于40.0、35.0、30.0、30.0与40.0 mm;女性应分别小于35.0、30.0、25.0、25.0与35.0 mm。结果在髋臼后柱壁不同进钉位点,应采取不同的进钉角度与长度以防螺钉误入髋关节腔。
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Objective To digitally measure the relevant anatomical parameters of safe screw placement for posterior column wall of the acetabulum,so as to provide data reference for the clinical treatment of screw placement for posterior wall and/or posterior column fractures.Methods 3D hip-bone models of 100 normal adults were reconstructed by Mimics 20.0.The acetabular posterior wall was divided into high posterior wall area involving the acetabular roof and the low posterior wall area without involving the acetabular roof.Sections M,D,E and N were obtained by cutting the high posterior wall area of the acetabulum,and sections F,G,H,I and J were obtained by cutting the low posterior wall area of the acetabulum.The following parameters were measured on each section:the angle and the length of the screw.Results In the entry points 5.0 mm away from the acetabular edge on sections M,D,E and N,the maximum safe entry angles of screws for men and women should not exceed 80°,70°,60° and 50°,respectively,and the entry lengths for men and women should not exceed 40.0mm and 35.0mm,respectively.On sections F,G,H,I and J,the screw angles of 5.0 mm,10.0 mm,20.0 mm and 30.0 mm away from the acetabular edge should be less than 50°,60°,80° and 90°,respectively.On sections F to J,the screw lengths of male should be less than 40.0 mm,35.0 mm,30.0 mm,30.0 mm and 40.0 mm,respectively,the screw lengths of female should be under 35.0 mm,30.0 mm,25.0 mm,25.0 mm and 35.0 mm respectively.Conclusions Different insertion angles and lengths should be adopted at different insertion points in the posterior column wall of the acetabulum to avoid the screw entering into the hip cavity.
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目的观察肘关节尺侧副韧带(UCL)的解剖学特征,对其后束(PB)进行解剖学分类,为肘关节精确解剖、韧带的外科修复提供参考依据。方法82例结构完整的人上肢标本,解剖UCL,观察PB的形态特征及变异,依据其与肘关节囊的关系划分类型;测量PB的长度、起点宽度、止点宽度等。结果(1)根据PB与肘关节囊的关系分为:①Ⅰ型:PB的前缘及后缘均位于关节囊表面,增厚并游离,呈独立型条带61%(50例);此类型男性、女性PB的长度分别是(20.92±2.59) mm、(17.28±2.07) mm,二者具有显著性差异(P=0.000,t=5.531);②Ⅱ型:PB的前缘与肘关节囊融合,后缘增厚游离16%(13例);③Ⅲ型:PB的后缘与肘关节囊融合,前缘增厚游离18%(15例);④Ⅳ型:PB的前缘、后缘均与肘关节囊融合,难以分辨5%(4例)。(2)男性PB以Ⅰ型与Ⅱ型较多,女性PBⅠ型与Ⅲ型较多,在类型构成方面具有显著性差异(χ~2=8.096,P= 0.035)。结论本实验对PB的分型,是对UCL解剖结构的补充;PB呈Ⅱ~Ⅳ等类型可能是导致其变异的重要因素;处理PB损伤时应考虑性别差异,便于结构功能恢复。
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Objective To clarify the morphological features of the posterior bundle (PB) of the ulnar collateral ligament of the elbow joint,so as to provide reference for anatomy of elbow joint and surgical repairs of ligaments.Methods A total of 82 adult elbow joints were dissected and the characteristics of the PB were noted.The length,widths of the origin and insertion of the PB were measured with a vernier caliber.Results (1)The PB was divided into four types according to the relation with the elbow joint capsule:① type Ⅰ,the anterior and posterior edges were located on the surface of the capsule and could be separated as a single ligament in 61% of cases.There was significant difference in length between male (20.92±2.59) mm and female (17.28±2.07) mm in this type (P=0.000,t=5.531).② typeⅡ,the anterior edge of PB was fused with elbow joint capsule,while the posterior edge was thickened and free in 16% of cases.③ type Ⅲ,the posterior edge of PB was fused with elbow joint capsule,while the anterior edge was thickened and free in 18% of cases.④ type Ⅳ,the anterior and posterior edges of PB could not be separated from the elbow joint capsule in 5% of cases.(2) Types Ⅰand Ⅱ were more commonly occurred in male,while types Ⅰand Ⅲ were observed in female frequently.There was significant difference in type composition (χ~2=8.096,P=0.035).Conclusions The new classification of the PB was proposed based on the supplement to the anatomy of UCL,which emphasized the relation with the joint capsule of the elbow Type Ⅱ ~ Ⅳ of PB maybe an important factor causing morphological variation.Gender difference should be considered when treating PB injury,so as to facilitate structural and functional recovery.
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目的基于中老年腰椎矢状面MRI测量椎基静脉孔(basivertebral foramen,BF)的解剖学参数,为相关手术提供解剖学依据。方法回顾2018年2月至2022年12月广州中医药大学第一附属医院43例成年患者,共计172例椎体的腰椎矢状面MRI,使用PACS影像系统测量L_1~L_4BF的深(basivertebral foramen depth,BFD)、BF的高(basivertebral foramen height,BFH)、椎体宽(vertebra width,VW)、椎基静脉孔上端至上终板距离(the upper end of BF between the upper boundary and the endplate,VH1)以及椎基静脉孔下端至下终板距离(the lower end of BF between the lower boundary and the endplate,VH2),计算BFD与VW的比值BFD/VW以及BFH与椎体高(vertebra height,VH)的比值BFH/VH。结果在STIR序列中,L1椎体BFD(3.93±1.58)mm低于L_3 (5.26±2.34)mm与L_4 (5.82±2.99)mm,有统计学意义(P<0.05);L_1椎体BFD/VW(0.12±0.05)与L4 (0.17±0.09)对比有统计学意义(P<0.05),且L_1~L_4的BFD/VW组间对比有统计学差异(P<0.05),各椎体的BFH/VH对比无统计学意义(P>0.05)。男性与女性对比,T_2WI序列中L_3椎体BFH男性(7.95±2.84)mm高于女性(6.30±1.93)mm,有统计学意义(P<0.05)。随着椎体序列的增长,BFD呈现逐渐增加的趋势,在STIR序列中更加明显。而BFH随椎体序列增加无明显起伏。结论中老年MRI矢状位STIR序列可作为其BF的临床测量标准,为腰椎手术方案的选择提供解剖学依据。
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Objective To provide further anatomical basis for lumbar vertebra operations by measuring anatomical parameters of lumbar vertebra basivertebral foramen (BF) based on sagittal MRI images.Methods Sagittal MRI images of 172 vertebral bodies of 43 adult patients admitted to the First Affiliated Hospital of Guangzhou University of Chinese Medicine and Dongguan Hospital of Guangzhou University of Chinese Medicine from February 2018 to December 2022 were retrospectively analyzed.The PACS imaging system was used to measure the BF depth (BFD),BF height (BFH),Vertebral width (VW),the upper end of BF between the upper boundary and the endplate (VH1),the lower end of BF between the lower boundary and the endplate (VH2),and calculate the ratio of BFD to vertebral body width (BFD/VW) and the ratio of BFH to vertebral body height (BFH/VH).Results After comparing lumbar vertebrae,the STIR sequence showed that BFD (3.93±1.58mm) of L1 vertebrae was lower than BFD of L_3 (5.26±2.34) mm and BFD of L_4 (5.82±2.99) mm,which was statistically significant (P<0.05).Also in the STIR sequence,BFD/VW of L1(0.12±0.05) was lower than that of BFD/VW of L_4(0.17±0.09) (P<0.05).Moreover,there were statistical differences in the comparison of BFD/VW in L_1-L_4 among the four groups (P<0.05).There was no statistical significance in the BFH/VH of each vertebral body (P>0.05).In the comparison between male and female,BFH of male L_3(7.95±2.84) mm was higher than that of female L_3(6.30±1.93) mm on T_2WI,which was statistically significant (P<0.05).With the increasing of the vertebrae sequence,BFD showed a gradually increasing trend,and it was more obvious in the STIR sequence.BFH had no obvious fluctuation with the increasing of vertebral body sequence.Conclusions STIR sequence in sagittal MRI image can be used as the clinical measurement standard of BF in middle-aged and elderly patients,which providing anatomical reference for the selection of lumbar surgical treatment.
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目的测量内蒙古地区髋关节置换术后假体位置参数,了解假体位置分布及解剖重建率。方法纳入内蒙古地区四家三级医院179例髋关节置换术后首次X线资料(年龄30~70岁),影像资料以JEPG格式导入Mimics21.0软件,采用多人重复测量取平均值的方法测量6项参数,包括髋臼假体外展角、前倾角、髋关节旋转中心垂直位置和水平位置、股骨偏心距及双下肢长度差异;比较术侧与健侧髋关节旋转中心位置、股骨头偏心距的差异,统计以上6项参数的解剖重建率。结果观察者间及观察者自身的组内相关系数为0.84~0.99,可靠性较好。健侧股骨头偏心距与术侧差异无统计学意义;术侧髋关节旋转中心垂直位置、水平位置与健侧相比,向内上方偏移,差异存在统计学意义(P<0.05)。髋臼假体外展角、前倾角、髋关节旋转中心垂直位置、水平位置、股骨头偏心距及双下肢长度差异的解剖重建率分别为79.90%、77.70%、43.02%、60.34%、60.30%、79.30%。结论本研究统计内蒙古地区髋关节置换术假体位置的分布情况,认为术后较难达到完全的解剖重建,其中髋关节旋转中心垂直位置、水平位置及股骨偏心距的解剖重建率偏低,需改进手术方法缩小两侧的差异。
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Objective To measure the position parameters of the prosthesis after hip arthroplasty in Inner Mongolia,and to understand the position distribution and anatomical reconstruction rate of the prosthesis in Inner Mongolia.Methods The X-ray data of hip arthroplasty were collected from four tertiary hospitals in Inner Mongolia,aged 30-70 years,and 179 cases were finally.The image data was imported into the Mimics 21.0 software in JEPG format measured by multiple people's repeated measurements and taking the average value,including acetabular prosthesis abduction angle,anteversion angle,hip rotation center position (vertical position,horizontal position),femoral offset,and leg length discrepancy,and the differences in the center of rotation of the hip joint and femoral offset between the operated side and the healthy side were compared,and the anatomical reconstruction rates of the above 6 parameters were counted.Results (1) The inter-observer and intra-observer correlation coefficients ranged from 0.84 to 0.99,showing good reliability.(2) There was no statistically significant difference in the femoral offset on the healthy side and the operated side,but there were statistically significant differences in the vertical position and horizontal position of the hip joint rotation center between the operated side and the healthy side (P<0.05),and compared with the healthy side,the center of rotation of the prosthesis on the operated side is shifted inwardly and upwardly.(3) The anatomical reconstruction rates of acetabular prosthesis abduction angle,anteversion angle,hip joint rotation center vertical position,horizontal position,femoral offset,and the leg length discrepancy were 79.90%,77.70%,43.02%,and 60.34%,60.30%,79.30%,respectively.Conclusions This study understands the distribution of prosthetic positions in hip arthroplasty in Inner Mongolia.It is difficult to achieve completely anatomical reconstruction after surgery.Among them,the anatomical reconstruction rate of the vertical position,horizontal position of the hip joint rotation center and femoral offset is low.Surgical methods need to be continuously improved to further narrow the difference between the two sides.
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目的三维数字化研究0~18岁人的骶骨形态与耻骨联合位置在不同年龄段及性别间的变化规律,为制定符合未成年人骶骨发育特征的摄影体位、优化骶骨X线图像及诊断提供参考。方法将收集到的0~18岁全腹部CT分为0~6岁、7~12岁、13~18岁3个年龄组,导入mimics21.0,利用三维数字化图像重组技术测量骶骨倾斜角(sacral slope,SS)、骶1~2倾斜角(S1~2T)、骶骨后凸角(sacral kyphosis,SK)、S2椎体前缘与骶4尾1倾斜线夹角(α角)、S1上终板与S2椎体前缘夹角(β角)、S4Co1倾斜线与S1上终板夹角(θ角)、耻骨联合上缘与骶骨下缘连线和躯体长轴垂线之间的夹角(角B),比较各参数在不同性别、年龄段间的差异。结果骶骨解剖学参数性别间比较,角B女性大于男性(P<0.001),其余无统计学差异;年龄组间比较,0~6岁组与13~18岁组SS、SK、α、β、θ,以及7~12岁组与13~18岁组SS差异有统计学意义,其余无统计学差异。结论未成年人生长发育过程中骶骨形态无性别差异,女性骶骨下缘与耻骨联合上缘所成角度大于男性。随年龄增长未成年人骶骨上端倾斜程度逐渐增加,骶骨下端倾斜程度逐渐减小。为获得更加清晰的骶骨影像,需根据性别、年龄调整X线入射角度。
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Objective To provide basic reference for the formulation of photographic positions in line with the characteristics of sacral development of minors,optimization of sacral X-ray images and diagnosis of diseases by investigating the change rules of sacral morphology parameters and pubic symphysis position of minors aged 0~18 years in different age groups and genders.Methods The collected total abdominal CT scans from 0 to 18 years old were divided into 3 age groups according to age:0 to 6 years old,7 to 12 years old,and 13 to 18 years old.The data was imported by mimics 21.0 and 3D digital image reconstruction technology was used to analyze sacral slope (SS),sacral 1-2 inclination Angle (S1~2T),sacral kyphosis Angle (sacral kyphosis,SK),S2 anterior margin and Sacro4 caudal-1 tilt line Angle (α Angle),S1 upper endplate and S2 anterior margin Angle (β Angle),S4Co1 oblique line and S1 upper endplate Angle (θ Angle),the line between the pubic union and the lower margin of the sacrum and the Angle between the vertical line of the long axis of the body (Angle B).The parameters in different genders and ages were compared.Results Angle B of sacral morphometry was greater in females than in males,and there was no significant difference in other parameters.There were significant differences in SS,SK,α,β,θ between 0~6 years old and 13~18 years old,and between 7~12 years old and 13~18 years old,but no significant differences in other age groups.Conclusions There was no gender difference in sacral morphology during the growth and development of juveniles.The Angle between the lower sacral margin and the superior symphysis of pubis is greater in juvenile females than in males.With the increasing of age,the degree of sacral tilt increased gradually,the degree of lower sacral tilt decreased.In order to obtain a clearer image of the sacrum the X-ray incidence Angle should be adjusted according to gender,age,and examination purpose.
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目的测量退行性腰椎侧凸(degenerative lumbar scoliosis,DLS)患者椎管形态学参数,分析其变化规律及其与脊柱-骨盆参数的相关性。方法收集DLS患者50例,分别在X线、CT及MRI上测量腰弯Cobb角、腰椎前凸角、顶椎位置、顶椎偏移距离、顶椎旋转度、顶椎侧方和前方滑移距离、骨盆投射角(pelvic incidence,PI)、骨盆倾斜角(pelvic tilt,PT)、骶骨倾斜角(sacral slope,SS)、凹侧和凸侧椎间孔高度、宽度和横截面积、硬膜囊横截面积、横径和前后径,分析椎管形态学变化规律及其与脊柱-骨盆参数的相关性。结果DLS患者的顶椎位于L_2~L_3椎体;其椎管相关参数最小处均位于L_(4/5)节段;椎间孔相关参数最小处均位于L_(2/3)节段。DLS患者L_(2/3)水平椎管及椎间孔的形态学参数与年龄、腰弯Cobb角及顶椎偏移距离存在相关性(P<0.05);而L_5/S_1水平椎间孔的形态学参数与PI、SS存在相关性(P<0.05)。结论DLS患者椎管最狭窄处多位于L_(4/5)节段,而椎间孔最狭窄处多位于L_(2/3)节段。顶椎区椎管狭窄程度、椎间孔狭窄程度与脊柱-骨盆参数之间存在一定的相关性。
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Objective To analyze the change pattern and its correlation with spinal-pelvic parameters by measuring morphological parameters of the spinal canal in patients with degenerative lumbar scoliosis (DLS).Methods Fifty cases of DLS patients were collected.Cobb angle of lumbar bending,anterior lumbar convexity angle,position of the parietal vertebra,distance of parietal offset,rotation of the parietal vertebra,distance of lateral and anterior slip of the parietal vertebra,pelvic parameters PI,PT,SS,height,width and cross-sectional area of the intervertebral foramen on the concave and convex sides,crosssectional area of the dural sac,transverse diameter and anterior-posterior diameter were measured on X-ray,CT and MRI,respectively.The patterns of morphological changes in the spinal canal and their correlation with spinal-pelvic parameters were analyzed.Results The parietal vertebra of DLS patients were located in the L_2~L_3 vertebra.The lowest spinal canal parameters were located at L_(4/5) level,the lowest intervertebral foramen parameters were located at L_(2/3) level.Morphological parameters of the spinal canal and intervertebral foramen at the L_(2/3) level correlated with age,cobb angle of lumbar bending,and distance of parietal offset in patients with DLS (P<0.05);while morphological parameters of the intervertebral foramen at the L_5/S_1 level were correlated with PI and SS (P<0.05).Conclusions The most narrowed spinal canal in DLS patients is mostly located at the L_(4/5) segment,while the most narrowed intervertebral foramen is mostly located at the L_(2/3) segment.There is a correlation between the degree of spinal canal stenosis and foraminal stenosis in the parietal region and spinal-pelvic parameters.
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目的为封闭治疗肩周炎提供解剖学基础。方法查找封闭注射治疗肩周炎的操作方法。利用30例肩部三维重建模型,探讨骨性定位标志与病变部位的几何关系,并获得改良的封闭注射方法。用改良方法对34例防腐标本进行封闭注射,经解剖验证注射的准确性。结果几何关系分析发现肩峰前角进针,7号针头呈扇形注射,几乎可注入整个肩峰下间隙;在喙突尖与肩峰前角连线的中点,向肱骨头可刺入关节腔。解剖发现肱二头肌腱与大结节前缘存在一定的间隙,可为进针点。改良的注射方法准确率为100%。结论熟悉肩部的几何关系和解剖特点,改良的封闭注射方法有助于提高封闭注射的准确性。
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Objective To provide anatomical basis for the treatment of scapulohumeral periarthritis using the local steroid injection.Methods The literature of the injection method for the treatment of scapulohumeral periarthritis by the local steroid injection were reviewed.The geometric relationship between the bone location markers and the lesion site was investigated by using 30 shoulder of three-dimensional models,and an improved method of local steroid injection was obtained.A modified method was used to perform closed injection on 34 antiseptic cadaver specimens,and the accuracy of the injection was verified by anatomy.Results 1.The geometric relationship analysis showed that the needle was inserted into the anterior corner of the acromion,and the No.7 needle was fan-shaped,and the needle could reach almost the entire subacromial space.At the midpoint of the line between the apex of coracoid process and anterior corner of the acromion,the needle may be inserted into the joint cavity towards the humerus head.2.Anatomically,it was found that there was a certain gap between the biceps brachii tendon and the anterior edge of greater tubercle,which could be the point of needle entry.3.The accuracy of the improved injection method was 100%.Conclusions Familiarity with the geometric relationship and anatomical characteristics of the shoulder is helpful to improve the feasibility and accuracy of local steroid injection.
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目的应用生物信息学的方法分析筛选头颈部鳞状细胞癌(HNSCC)巨噬细胞中的潜在关键基因,为HNSCC的预后提供靶点。方法基于在线数据库,利用一致流形近似与投影(UMAP)降维,捕获巨噬细胞群;进一步通过t-分布随机近邻嵌入(tSNE)聚类降维分析肿瘤组织与正常组织细胞群分布的变化并筛选差异基因的表达;运用Monocle包对关键风险基因在不同发育阶段细胞中的表达情况进行分析;利用Kaplan-Meier Plotter在线数据平台分析生存曲线;运用空间转录组技术验证关键基因在组织中的表达映射;多色荧光免疫组化进行临床样本的验证。结果捕获得到7个巨噬细胞亚群,其中第1亚群仅存在于肿瘤组织中且分泌型磷蛋白1(SPP1)基因高富集。SPP1高表达趋向巨噬细胞M2型极化并处于细胞分化的终末阶段。SPP1+巨噬细胞糖酵解、缺氧、上皮间质化、血管生成等功能活跃,与HNSCC患者的预后呈负相关。结论SPP1可能成为HNSCC中有价值的预后生物标志物。
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Objective To analyze and screen potential key genes in macrophages of head and neck squamous cell carcinoma (HNSCC) by bioinformatics,and to provide a target for the prognosis of HNSCC.Methods The macrophage population was captured by using uniform manifold approximation and projection (UMAP) dimensionality reduction based on online database.Furthermore,T-distributed random neighbor embedding (tSNE) clustering was used to analyze the changes of cell population distribution in tumor tissue and normal tissue,and to screen the expression of differential genes.Monocle package was used to analyze the expression of key risk genes in cells at different developmental stages.The survival curve was analyzed using Kaplan-Meier Plotter online data platform.Spatial transcriptome technology was used to verify the expression mapping of key genes in tissues.Clinical samples were validated by multicolor fluorescence immunohistochemistry.Results Seven macrophage subgroups were captured,of which the first subgroup existed only in tumor tissue and SPP1 gene was highly enriched.The high expression of SPP1 tended to the M2-type polarization of macrophages and was in the terminal stage of cell differentiation.SPP1+macrophages had active functions such as glycolysis,hypoxia,epithelialization,and angiogenesis.The expression of SPP1+macrophages was negatively correlated with the prognosis of HNSCC patients.Conclusions SPP1 may be a valuable prognostic biomarker in HNSCC.
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目的比较拮抗剂方案中行新鲜胚胎移植和冻融胚胎移植的临床结局。方法回顾性分析2575例患者行拮抗剂方案助孕的临床资料,其中鲜胚移植周期1328例,冻胚移植周期1247例。结果冻胚移植组的血清AMH值、AFC显著高于鲜胚移植组,差异有统计学意义(P<0.05),其余基础资料无统计学差异(P>0.05)。冻胚移植组hCG日FSH低于鲜胚移植组,E2、P高于鲜胚移植组,差异有统计学意义(P<0.05)。冻胚移植组的获卵数、成熟卵子数、优质胚胎数均显著高于鲜胚组,差异有统计学意义(P<0.05)。冻胚移植组的移植胚胎数显著低于鲜胚移植组,临床妊娠率、着床率、活产率显著高于鲜胚移植组,异位妊娠率、多胎妊娠率显著低于鲜胚移植组,差异有统计学意义(P<0.05)。两组的中重度OHSS发生率、流产率、妊娠期糖尿病发生率、妊娠期高血压发生率差异无统计学意义(P>0.05)。冻胚移植组的单胎出生体重显著高于鲜胚移植组,差异有统计学意义(P<0.05)。结论拮抗剂方案中冻胚移植亦可获得较好的临床结局,可作为一种有效的补充方案。
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Objective To compare the clinical outcomes of fresh embryo transfer and frozen-thawed embryo transfer (FET) in the gonadotropin-releasing hormone antagonist (GnRH-A) protocol.Method The clinical data of 2575 women undergoing GnRH antagonist protocol cycle,including 1328 cases of fresh embryo transfer and 1247 cases of FET were retrospectively analyzed.Results The AMH level and AFC in the FET group were significantly higher than those in the fresh embryo transfer group (P<0.05),and there was no significant difference in other baseline characteristics between the two group (P>0.05).The FSH level on hCG day in the FET group was significantly lower than that in the fresh embryo transfer group,and E2,P level on hCG day in the FET group were significantly higher than those in the fresh embryo transfer group (P<0.05).The total number of oocytes retrieved,matured oocyte,high-quality embryos in the FET group were significantly higher than those in the fresh embryo transfer group (P<0.05).The mean number of embryos transfer in the FET group was significantly lower than that in the fresh embryo transfer group,the clinical pregnancy rate,implantation rate and live birth rate in the FET group were significantly higher than those in the fresh embryo transfer group,the ectopic pregnancy rate and the multiple pregnancy rate in the FET group were significantly lower than those in the fresh embryo transfer group (P<0.05).There was no significant difference in the incidence of moderate-severe OHSS,miscarriage rate,incidence of GDM and gestational hypertension between the two groups (P>0.05).The singleton birth weight in the FET group was significantly higher than that in the fresh embryo transfer group,with statistical difference (P<0.05).Conclusions In the GnRH antagonist protocol cycle,FET can obtain good clinical outcome and can be used as an effective supplemental regimen.
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目的探讨连翘苷通过腺苷酸活化蛋白激酶(adenosine monophosphate activated protein kinase,AMPK)/哺乳动物雷帕霉素靶蛋白(mammalian target of rapamycin,mTOR)/p70核糖体S6蛋白激酶(p70 S6 kinase,p70S6K)信号通路介导的自噬对感染性休克小鼠急性肺损伤(Acute lung injury,ALI)的影响。方法随机选择12只小鼠作为对照组,其余小鼠通过腹腔注射20 mg·kg~(-1)脂多糖(Lipopolysaccharide,LPS)构建感染性休克小鼠模型,将感染性休克小鼠随机平分为模型组、低、中、高剂量实验组(5 mg·kg~(-1)、10 mg·kg~(-1)、20 mg·kg~(-1)连翘苷)、高剂量+抑制剂组(20 mg·kg~(-1)连翘苷+20 mg·kg~(-1) AMPK抑制剂compound C),每组均12只小鼠。称量肺干重及湿重,计算W/D比值;ELISA法检测BALF中炎性因子肿瘤坏死因子-α(tumor necrosis factor -α,TNF-α)、白细胞介素1β(interleukin-1β,IL-1β)、白细胞介素6(interleukin-6,IL-6)水平、血清内毒素(endotoxin,ET)含量、肺组织髓过氧化物酶(myeloperoxidase,MPO)活性;HE染色检测肺组织病理变化;Western blot检测自噬蛋白微管相关蛋白-轻链3(microtubule-associated protein -light chain3,LC3)-II/I、Beclin1、Ras相关GTP结合蛋白7(Rasassociated GTP binding protein7,Rab7)、溶酶体关联膜蛋白2(lysosomal associated membrane protein2,LAMP2)、AMPK/mTOR/p70S6K信号通路蛋白表达。结果对照组、模型组、低、中、高剂量实验组和高剂量+抑制剂组小鼠肺组织LC3-II/I比值分别为1.43±0.14、0.73±0.07、0.81±0.07、1.12±0.10、1.39±0.13、0.76±0.08,Beclin1蛋白水平分别为1.05±0.11、0.43±0.05、0.50±0.05、0.76±0.08、0.98±0.10、0.46±0.05,Rab7蛋白水平分别为1.53±0.17、0.67±0.06、0.70±0.07、1.04±0.10、1.41±0.14、0.69±0.06,LAMP2蛋白水平分别为1.47±0.15、0.72±0.07、0.81±0.08、1.09±0.11、1.35±0.13、0.74±0.07,p-AMPK/AMPK蛋白水平分别为0.95±0.05、0.33±0.03、0.39±0.04、0.68±0.07、0.91±0.09、0.36±0.04,p-mTOR/mTOR蛋白水平分别为0.28±0.02、0.94±0.06、0.88±0.07、0.57±0.05、0.30±0.03、0.87±0.09,p70S6K蛋白水平分别为0.32±0.07、0.96±0.04、0.90±0.07、0.69±0.06、0.38±0.04、0.92±0.06。上述指标:模型组与对照组比较,差异均有统计学意义(均P<0.05);中、高剂量实验组与模型组比较,差异均有统计学意义(均P<0.05);高剂量+抑制剂组与高剂量实验组比较,差异均有统计学意义(均P<0.05)。结论连翘苷可能通过调控AMPK/mTOR/p70S6K信号通路介导的自噬对感染性休克小鼠ALI起到改善作用。
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Objective To investigate the impact of phillyrin on acute lung injury (ALI) in septic shock mice through autophagy mediated by adenosine monophosphate activated protein kinase (AMPK)/mammalian target of rapamycin (mTOR)/p70 S6 kinase(p70S6K) signal pathway.Methods Twelve mice were randomly selected as the control group,and the rest of the mice were injected intraperitoneally with 20 mg·kg~(-1) LPS to construct the model of septic shock,the mice with septic shock were randomly divided into a model group,an Experimental-L,-M,-H group (5 mg·kg~(-1),10 mg·kg~(-1),20 mg·kg~(-1) phillyrin),and an Experimental -H~+ compound C group (20 mg·kg~(-1) phillyrin+20 mg·kg~(-1) AMPK inhibitor compound C),there were 12 mice in each group.The lung dry weight and wet weight were weighed,and the W/D ratio was calculated;the levels of inflammatory factors tumor necrosis factor- α (TNF- α),interleukin-1β (IL-1β),interleukin-6 (IL-6) in BALF,serum endotoxin (ET) and myeloperoxidase (MPO) of lung tissue were detected by ELISA;HE staining was applied to detect pathological changes of lung tissue;Western blot was applied to detect the expression of autophagic proteins microtubule-associated protein -light chain 3 (LC3-II/I),Beclin 1,Ras-associated GTP binding protein 7 (Rab7),lysosomal associated membrane protein 2 (LAMP2) and AMPK/mTOR/p70S6K signaling pathway proteins.Results In control group,model group,Experimental- L,-M,-H group and Experimental-H~+ compound C group LC3-II/I ratios were 1.43±0.14,0.73±0.07,0.81± 0.07,1.12±0.10,1.39±0.13,0.76±0.08,respectively.Beclin1 protein levels were 1.05±0.11,0.43±0.05,0.50± 0.05,0.76±0.08,0.98±0.10,0.46±0.05,respectively.Rab7 protein levels were 1.53±0.17,0.67±0.06,0.70± 0.07,1.04±0.10,1.41±0.14,0.69±0.06,respectively.LAMP2 protein levels were 1.47±0.15,0.72±0.07,0.81± 0.08,1.09±0.11,1.35±0.13,0.74±0.07,respectively.p-AMPK/AMPK protein levels were 0.95±0.05,0.33± 0.03,0.39±0.04,0.68±0.07,0.91±0.09,0.36±0.04,respectively.p-mTOR/mTOR protein levels were 0.28± 0.02,0.94±0.06,0.88±0.07,0.57±0.05,0.30±0.03,0.87±0.09,respectively.The protein levels of p70S6K were 0.32±0.07,0.96±0.04,0.90±0.07,0.69±0.06,0.38±0.04,0.92±0.06,respectively.There were statistical differences between the model group and the control group (all P<0.05).There were statistical differences between Experimental-M,-H group and model group (all P<0.05).There were significant differences between Experimental-H~+ compound C group and Experimental-H group (all P<0.05).Conclusions Phillyrin may improve ALI in septic shock mice by regulating autophagy mediated by AMPK/mTOR/p70S6K signaling pathway.
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目的探讨推拿扌衮法对家兔骨骼肌钝挫伤后相关纤维蛋白表达的影响,以及对骨骼肌钝挫伤修复的作用机制。方法健康成年新西兰兔15只,随机分为空白组(A)、模型组(B)和治疗(C)组,每组5只。使用自制改良重力锤打击装置对模型组和治疗组建立骨骼肌钝挫伤模型,治疗组家兔于造模成功后7 d给予推拿扌衮法干预,频率140次/min,2次/d,3 min/次,共治疗3 d。干预结束后1 d进行取材。 HE和Masson染色观察兔股四头肌病理改变;Western-blot检测各组股四头肌基质金属蛋白酶-9(matrix metalloproteinases-9,MMP-9)、特异性抑制剂-1(tissue inhibitor of metalloproteinases-1,TIMP-1)、转化生长因子-β1(transforming growth factor-β1,TGF-β1)及I型胶原蛋白(I collagen,COL-I)表达。结果空白组肌组织结构规整;模型组肌组织形态迥异,边界模糊,间隙显著增宽,炎细胞浸润显著,四周胶原纤维生成增加;治疗组肌组织结构相对完整,间隙缩小,可见少量炎细胞浸润与胶原纤维生成,其病理修复程度显著优于模型组。检测家兔股四头肌MMP-9、TIMP-1、TGF-β1、COL-I表达,与空白组相比,模型组与治疗组明显增加(P<0.01);但治疗组显著低于模型组(P<0.01)。结论推拿扌衮法能够通过减少细胞外基质过度沉积抑制骨骼肌纤维化,其作用机制可能与下调MMP-9、TIMP-1、TGF-β1及COL-I表达量有关。
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Objective To investigate the effect of tui na rolling method on the expression of relevant fibrosis proteins after blunt contusion injury of skeletal muscle in rabbits,and to explore the mechanism of action of tui na rolling method on the repair of blunt contusion injury of skeletal muscle.Methods Fifteen healthy adult New Zealand rabbits were randomly divided into three groups of blank (A),model (B) and treatment (C),with five rabbits in each group.Blunt contusion of skeletal muscle was modelled in rabbits of groups B and C using a self-constructed modified gravity hammer percussion device.The rabbits in group C were given the intervention 7 d of tui na rolling after successful modelling,at a frequency of 140 beats/min,2 times/d,3 min/session,for a total of 3 d of treatment.Tissue sampling was performed 1 d after the end of the intervention.Histological changes of rabbit quadriceps femoris muscle were observed by HE and Masson staining,and MMP-9,TIMP-1,TGF- β1,and COL-I expression of quadriceps femoris muscle of rabbits in each group were detected by Western-Blot.Results The muscle tissue of the blank group was of regular structure,the muscle tissue of the model group was of very distinct shape,with blurred margins,significantly enlarged gaps,significant invasion of inflammatory cells,and increased collagen fiber production in the surrounding area,the muscle tissue of the treatment group was relatively more intact in structure,with the gaps narrowed,and a small amount of invasion of inflammatory cells and collagen fiber production could be seen,and the degree of its pathological repair was significantly better than that of the model group.Compared with the blank group,the expression of MMP-9,TIMP-1,TGF-β1,and COL-I in quadriceps femoris muscle of rabbits in the model group and the treatment group were significantly increased (P<0.01).However,the expression of MMP-9,TIMP-1,TGF-β1,and COL-I in quadriceps femoris muscle of rabbits in the treatment group was significantly lower than that in the model group (P<0.01).Conclusions Tui na rolling method is ability to inhibit skeletal muscle fibrosis by reducing the excessive deposition of extracellular matrix,and then inhibit skeletal muscle fibrosis,and its mechanism of action maybe related to the suppression of the expression of MMP-9,TIMP-1,TGF-β1,and COL-I.
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目的探讨有跌倒史的老年人坐立运动中肌肉募集机制是否发生变化。方法招募17名健康年轻人、17名健康老年人及9名有跌倒史的老年人,采集右下肢16块肌肉的表面肌电信号(sEMG)和足底压力中心(COP)轨迹,使用Falls Efficacy Scale-International(FES-I)评估跌倒风险,通过非负矩阵分解(NNMF)提取肌肉协同。结果3组在肌肉协同数量上无显著差异。有跌倒史老年人坐立运动初期,提前激活腘绳肌和踝关节跖屈肌,在运动的后期,这种提前激活转变为额外的肌肉活动,与健康组形成对比。此外,COP偏移量和FES-I评分显著增加,指示运动稳定性不足。结论坐立运动中有跌倒史老年人腘绳肌和踝关节跖屈肌的异常激活可能影响下肢稳定和肌肉募集策略的改变。
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Objective To explore the change of muscle recruitment mechanisms during sit-to-stand(STS) movements in elderly individuals with a history of falls.Methods A total of 17 healthy young adults,17 healthy elderly adults,and 9 elderly individuals with a history of falls were recruited.Surface electromyography (sEMG) signals and the trajectory of the center of pressure (COP) from 16 muscles of the right lower limb were collected.Falls Efficacy Scale-International (FES-I) was used to assess fall risk,and muscle synergies were extracted by non-negative matrix factorization (NNMF).Results There was no significant difference in the number of muscle synergies among the three groups.In the elderly individuals with a history of falls,early activation of the hamstring and ankle plantar flexors at the beginning of sit-tostand movement was transformed into additional muscle activity at the later stage of movement,in contrast to the healthy group.Furthermore,COP offsets and FES-I scores were significantly increased,indicating a lack of movement stability.Conclusions Abnormal activation of hamstrings and ankle dorsiflexion in elderly individuals with a history of falls during STS movements may affect lower limb stability and changes in muscle recruitment strategies.
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目的探讨基于CT断层扫描影像数据融合的三维可视化技术及数字泌尿外科虚拟诊疗在肾上腺肿瘤中的应用价值。方法选取贵阳市第二人民医院泌尿外科2016年9月~2023年04月期间收治的肾上腺肿瘤手术患者进行回顾性分析。共纳入病例19例,三维重建肾上腺肿瘤(3D组)12例(男性3例,女性9例),平均年龄(44.92±13.28)岁。3D组12例患者均在术前使用增强CT影像数据进行三维重建,并使用重建模型了解肿瘤及占位位置,以及肿瘤处与血管及周围组织器官的关系,依据三维可视化模型制定手术计划、术中指导及进行医患沟通。未三维重建手术(CT组)7例(男性3例,女性4例),平均年龄(35.14±11.25)岁。比较两组患者的一般资料、手术方法、围手术期数据,并使用SPSS 26.0进行数据分析和处理。结果19例手术中,18例手术均顺利完成,CT组1例手术因术前评估不够精确,术中发现肿瘤巨大、解剖关系复杂,无法显露完整肿瘤、中央静脉和肾静脉,转为开放手术。3D组患者的手术时间小于CT组,差异具有统计学意义(P<0.05)。两组一般资料(性别、年龄)、术中出血量、术后住院时间和拔除引流管时间相比,差异均无统计学意义(P>0.05)。结论三维可视化及实景重建技术是构建数字泌尿外科虚拟诊疗的重要基础,三维重建模型可以减少肾上腺肿瘤手术中的解剖迷失以实现术中精准切除,从而缩短手术时间。有利于降低手术风险,在泌尿外科具有较高的临床应用价值,值得进一步临床应用及推广。
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Objective To explore the application value of 3D reconstruction technology of CT scanning and digital virtual surgery diagnosis and treatment system in adrenal tumors.Methods Data on 20 patients diagnosed with adrenal tumors and completed 3D reconstruction in The Second People's Hospital of Guiyang from September 2016 to April 2023 were reviewed.A total of 19 cases were collected,including 12 cases of three-dimensional reconstruction adrenal tumors (3D group),3 males and 9 females,with the mean age of (44.92±13.28) year.All the 12 patients in 3D group were three-dimensional reconstructed with enhanced CT image data before operation,and the reconstructed model was used to understand the tumor and its occupying position,as well as the relationship between the tumor and blood vessels and surrounding tissues and organs.The operation plan,intraoperative guidance and doctor-patient communication was made according to the 3D reconstruction image.There were 7 cases without three-dimensional reconstruction (CT group),the mean age was (35.14±11.25) years.There were 3 males and 4 females in the CT group.The general information,surgical methods and perioperative data of the two groups were compared.The data were analyzed by using SPSS 26.0.Results Among the 19 cases,18 cases were successfully completed.One case in the CT group was converted to open surgery due to insufficiently accurate preoperative evaluation,which resulted in the discovery of a huge tumor and complex anatomical relationship during the operation,and the inability to expose the complete tumor,central vein and renal vein.The operation time in the 3D group was shorter than that in the CT group,with a statistically significant difference (P<0.05).There were no significant differences in general information(age and gender),intraoperative bleeding volume,postoperative length of stay,and drainage tube removal time between the two groups (P>0.05).Conclusions 3D visualization and realistic reconstruction technology is an important foundation for construction of virtual diagnosis and treatment of digital urology.3D reconstruction models can reduce anatomical disorientation in adrenal tumor surgery to achieve accurate intraoperative resection,thereby shortening the surgical time.It is beneficial to reduce surgical risk and has high clinical application value in urology surgery,which is worth of further clinical application and promotion.
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目的探讨神经内镜联合显微镜行微血管减压术治疗原发性三叉神经痛的临床疗效。方法回顾分析78例行微血管减压术治疗的原发性三叉神经痛患者资料,其中常规显微镜组(A组)36例,神经内镜联合显微镜微血管减压术(B组)42例,分析比较两组术中责任血管发现率、手术并发症及术后疗效。结果B组责任血管发现率(95.2%)明显高于A组责任血管发现率(80.6%)、治愈率(97.6%)高于A组(83.3%),两者差异均有统计学意义(P<0.05);术后并发症B组(14.3%)比A组(30.6%)无明显差异(P>0.05)。结论神经内镜联合显微镜微血管减压术治疗三叉神经痛有助于避免责任血管遗漏,提高责任血管发现率和手术治愈率。
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Objective To evaluate the clinical effect of primary trigeminal neuralgia treatment by neuroendoscopy combined with microvascular decompression under microscope.Methods A retrospective analysis was made on 78 patients with primary trigeminal neuralgia treated by microvascular decompression,with 36 cases were treated by microvascular decompression under microscope (group A),and the other 42 cases were treated under neuroendoscopy combined with microscope (group B).The discovery rate of offending vessels,complications rate,and therapeutic efficacy were compared in the two groups after treatment.Results The discovery rate of offending vessels in the group B (95.2%) was significantly higher than that of the group A (80.6%);The total effective rate of the group B (97.6%) was higher than that of the group A (83.3%).There were statistical differences in the discovery rate of offending vessels and total effective rate in the two groups (P<0.05).There was no statistical difference in the postoperative complications between group A (30.6%) and group B (14.3%) (P>0.05).Conclusions The treatment of primary trigeminal neuralgia with neuroendoscopy combined with microvascular decompression microscope is of high clinical application value to improve the discovery rate of offending vessels and cure rate.
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目的探究骨盆髋臼骨折术中3D打印技术辅助骶髂螺钉置入的准确性及其学习曲线。方法选择2020年1月~2023年1月我院收治的112例骨盆髋臼骨折患者,根据是否使用3D打印技术分为常规组(56例)和3D打印组(56例),比较两组临床资料;线性回归分析单枚骶髂螺钉置入时间与手术例数的相关性,评价3D打印技术的学习曲线。结果3D打印组的手术时间、单枚骶髂螺钉置入时间、骨折愈合时间明显短于常规组,术中出血量、围手术期输血量、导针穿刺次数、术中X线透视次数明显少于常规组,骶髂螺钉置入位置优良率、术后骨折复位优良率、髋关节功能恢复优良率明显高于常规组(P<0.05)。线性回归分析结果显示,3D打印组与常规组单枚骶髂螺钉置入时间与手术例数均呈明显负相关(r=-0.842、-0.590,P<0.001),3D打印组回归方程为单枚骶髂螺钉置入时间=69.839-4.413×手术例数,R~2= 0.709,常规组为单枚骶髂螺钉置入时间=16.243-0.111×手术例数,R~2=0.348。结论骨盆髋臼骨折手术应用3D打印技术能够显著提高骶髂螺钉置入的准确性,增加手术安全性,且随着手术例数增加,3D打印技术辅助下置钉时间明显缩短。
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Objective To explore the accuracy and learning curve of sacroiliac screw implantation assisted by 3D printing technique in pelvic acetabular fracture.Methods A total of 112 patients with pelvic acetabular fractures treated in our hospital from January 2020 to January 2023 were selected and divided into a conventional group (n = 56) and a 3D printing group (n=56) according to whether 3D printing technique was used or not before operation.The clinical data of the two groups were compared.The correlation between the placement time of single sacroiliac screw and the number of surgical cases was analyzed by linear regression,and the learning curve of 3D printing technique was evaluated.Results The surgical time,insertion time of a single sacroiliac screw,and fracture healing time of the 3D printing group were significantly shorter than those of the conventional group.The intraoperative bleeding volume,perioperative blood transfusion volume,number of needle punctures,and intraoperative X-ray fluoroscopy frequency were significantly lower than those of the conventional group.The excellent and good rate of sacroiliac screw insertion position,postoperative fracture reduction,and hip joint function recovery were significantly higher than those of the conventional group (P<0.05).The results of linear regression analysis showed that there was a significant negative correlation between the insertion time of a single sacroiliac screw and the number of surgical cases in the 3D printing group and regular group (r=-0.842,-0.590,P<0.001).The regression equation of 3D printing group was insertion time of a single sacroiliac screw=69.839-4.413×Number of surgical cases,R~2=0.709,and that of regular group was 16.243-0.111×Number of surgical cases,R~2=0.348.Conclusions The application of 3D printing technology in the operation of pelvic acetabular fracture can significantly improve the accuracy of sacroiliac screw placement and increase the safety of operation,and with the increasing of the number of surgical cases,the nail placement time assisted by 3D printing technology is significantly shortened.
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目的观察牛津大学关节评分(Oxford Shoulder Score,OSS)对胸腔镜手术患者术后同侧肩痛(ipsilateral shoulder pain,ISP)的评估效果。方法择期全麻下侧卧位胸腔镜手术患者500例,年龄18~78岁,分别于术前1 d和术后第1 d在病区面对面、术后4~6周电话随访获取OSS。对术前OSS≥19分患者数据进行独立分析,并在手术体位摆放时予以保护。结果最终纳入研究465例,术前OSS≥19分患者1%(9例),术后均未发生ISP;余456例患者中,发生ISP者3.44%(16例),其手术时间长于未发生ISP患者,术后OSS较高,术后第1 d肩关节活动受限,显著低于术前(P<0.05或0.01)。结论术中对术前OSS异常患者加以体位保护,可有效预防发生术后ISP。
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Objective To investigate the efficacy of Oxford Shoulder Score(OSS)for preventing postoperative ipsilateral shoulder pain (ISP) in patients undergoing thoracoscopic surgery.Methods A total of 500 patients who underwent selective thoracoscopic surgery in the lateral position with general anesthesia were enrolled.Complete OSS data were questioned using in-depth interviews in the afternoon before the operation and the first postoperative day,and telephone was follow-up at 4-6 weeks after the operation.Special protections and statistical analysis were designed for the patients with preoperative OSS ≥19.Results A total of 465 patients were included in the study,16 cases presented ISP with a longer operative duration and higher postoperative OSS compared to those without ISP,and shown limitation of range of motion of ipsilateral shoulder in the first postoperative day (P<0.05 or 0.01).However,9 cases with preoperative OSS ≥ 19 didn't develop ISP.Conclusions The protective procedures of the lateral posture can minimize postoperative ISP for the patients with a high preoperative OSS.
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梯度点阵结构由于压缩时具有优秀的吸能能力,目前常作为吸能组件被应用于航天、国防和医疗等领域。但随着现代工业的发展,工程领域对其压缩性能提出了更高的要求,为使其进一步优化,有必要探讨单胞构型、结构参数和压缩性能之间的关系。因此本研究通过选区激光熔化(selective laser melting, SLM)成形了2种梯度差的AlSi10Mg变杆径梯度体心立方(body-centered cubic, bcc)和金刚石(diamond, Diam)结构,结合有限元分析(finite element analysis, FEA)研究梯度差对压缩性能的影响,并对2种单胞构型进行对比。准静态单轴压缩实验的结果表明,在同相对密度下,当单胞构型相同时,随着梯度差的增加单位体积吸能量明显增加,而梯度差相同时,Diam梯度点阵结构的压缩模量、屈服强度、抗压强度和最大峰值应力均高于bcc,同时其单位体积吸能量和吸能效率也高于bcc。
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Gradient lattice structure is commonly used as energy-absorbing components in aerospace, national defense and medical fields due to its excellent energy absorption ability when compressed. However, with the development of modern industry, the engineering field has put forward higher requirements for its compression properties. To achieve further optimization, it is necessary to study the relationship between compression properties and cell, structural parameters. Two AlSi10Mg rod-diameter-change gradient body-centered cubic (bcc) and diamond (Diam) structures with different gradient gaps were formed by selective laser melting (SLM) to investigate the effect of gradient gap on the compression properties combined with finite element analysis (FEA), and the two cells were compared. The results of quasi-static uniaxial compression experiments show that the absorbed energy per unit volume increases significantly with the increase in gradient gap at the same relative density with the same cell. The compressive modulus, yield strength, compressive strength and peak stress of Diam gradient lattice structure are higher than those of bcc structure when the gradient gap and relative density are the same, and its absorbed energy per unit volume and energy absorption efficiency are also higher than those of bcc structure.
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基于XRD、XPS、H_2-TPR等表征方法以及活性评价方法,研究了不同浓度La_2O_3掺杂CDPF样品水热老化状态下的理化特性与催化活性。结果表明:随着La_2O_3掺杂浓度增加,CDPF老化样品衍射特征峰位向大角度偏移程度以及结晶度均呈先降低后增加的趋势。La_2O_3掺杂能够较好地抑制样品在高温水热老化过程中的烧结和畸变,并且可以有效抑制活性位数量的减少,使CDPF表面Pt原子浓度基本保持不变,对CO、C_3H_8和NO催化性能的劣化率降低,并且随掺杂浓度的增大,CDPF抗老化性能有增强的趋势。
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Based on XRD, XPS, H_2-TPR and other characterization methods and activity evaluation methods, the physical and chemical properties and catalytic activity of CDPF (catalyzed DPF) samples doped with different concentrations of La_2O_3 under hydrothermal aging condition were studied. The results show that with the increase in La_2O_3 doping concentration, the diffraction characteristic peak shifts a large angle and the crystallinity of CDPF aging samples show a trend of decreasing and then increasing. La_2O_3 doping can better inhibit the sintering and distortion of samples during hydrothermal processing and can effectively inhibit the reduction of active quantity, so that the concentration of Pt atoms on the surface of CDPF remains basically unchanged, and the degradation rate of CO, C_3H_8 and NO catalytic performance decreases. With the increase in La_2O_3 doping concentration, the CDPF tends to reverse the trend of aging.
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利用扫描电子显微镜(scanning electron microscope,SEM)、光学显微镜(optical microscope,OM)、拉伸、蠕变、疲劳试验机等研究了一种新型镍基粉末高温合金FGH4113A(WZ-A3)在2种热处理状态下的显微组织和力学性能,为双性能热处理研究提供组织与力学性能依据。结果表明:FGH4113A合金在双性能热处理中,过固溶与亚固溶态组织与力学性能具有明显的双模特性;室温下,亚固溶态相比过固溶态屈服强度高10.6%,800 ℃下,过固溶态相比亚固溶态屈服强度高11.7%;与同样是亚固溶或过固溶的其它合金相比,FGH4113A的拉伸强度优于ME3合金,与LSHR合金相当;FGH4113A合金在750 ℃/450 MPa的蠕变变形以位错滑移机制主导,弥散分布的小尺寸硼化物有助于抗蠕变性能的提高,其抗蠕变性能全面超过ME3合金,与LSHR合金相当;过固溶态的粗晶组织在裂纹扩展中具有更长的滑移带,在循环载荷中具有较低的累积损伤,抗裂纹扩展能力优于亚固溶态;过固溶态的裂纹扩展断口呈现穿晶断裂特征,亚固溶态由于细晶粒边界的一次γ′的存在降低了晶界的抗裂纹扩展能力,断口较粗糙,呈现沿晶-穿晶混合断裂特征。
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The microstructure and mechanical properties of a novel nickel-based powder superalloy FGH4113A under two heat treatment conditions were studied by scanning electron microscope (SEM), optical microscope (OM), tensile, creep and fatigue testing, providing the basis for the research of dual microstructure heat treatment (DMHT). The results show that the supersolvus and subsolvus microstructure and mechanical properties have obvious dual-mode. At room temperature, the yield strength of subsolvus sample is 10.6% higher than that of supersolvus sample, and at 800 ℃, the yield strength of supersolvus samples is 11.7% higher correspondingly. The tensile strength of FGH4113A is better than that of ME3 and equivalent to that of LSHR. The creep deformation of FGH4113A alloy at 750 °C/450 MPa is dominated by the dislocation slip mechanism, and the dispersed small-sized borides are conducive to the creep performance improvement. FGH4113A has excellent creep properties, which is better than ME3 and equivalent to LSHR. The coarse-grained structure in the supersolvus sample has a longer slip band in crack propagation, resulting in lower cumulative damage under cyclic loading, and the crack growth resistance is better than that of subsolvus sample. The crack propagation fracture of the supersolvus sample is characterized by transgranular fracture. The existence of primary γ′ on the fine grain boundary reduces the crack growth resistance, and the fracture is rough, showing mixed fracture characteristics of intergranular and transgranular.
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铁镍基合金长期服役于较高温度下,因此高温下的组织稳定性是合金的重要指标之一。利用扫描电子显微镜(SEM)、透射电子显微镜(TEM)、电子探针(EPMA)、化学相分析等手段对750 ℃不同时效时间下新型铁镍基高温合金21Cr-32Fe-41Ni组织与性能演变规律进行研究。结果表明,长期时效后合金中析出相主要有γ′相、σ相、α-Cr相以及MC相。在时效500 h内,基体中弥散分布的球形γ′相的质量分数和尺寸快速增加。时效时间从500 h增加至2000 h, γ′相的质量分数和尺寸增加速率逐渐降低。在长期时效过程中,σ相沿晶呈块状或条状分布,并与α-Cr相同时在晶内以针状或条状析出。随时效时间增加,σ相和α-Cr相数量增加,逐渐粗化。沿晶不连续分布的σ相逐渐相连,存在向网状分布发展的趋势。随时效时间增加至2000 h,合金强度先升高后降低,在时效500 h后达到峰值,硬度保持增加趋势。
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Fe-Ni based alloys serve in high temperature environment for a long time, so the microstructure stability at high temperature is one of the important indexes of the alloys. The microstructure and properties evolution of a new Fe-Ni based superalloy 21Cr-32Fe-41Ni at 750 ℃ for different aging time were investigated by scanning electron microscope (SEM), transmission electron microscope (TEM), electron probe microanalysis (EPMA) and chemical phase analysis. The results show that the precipitates in the alloy are mainly γ′, σ, α-Cr, and MC phases after long-term aging. The mass fraction and size of the dispersed spherical γ′ in the matrix are increased rapidly within 500 h aging. With the increase in aging time from 500 h to 2000 h, the increase rate of mass fraction and size of γ′ gradually decreases. During the long-term aging process, the σ phases are distributed along the grain boundaries in block or strip shape and within grains in needle or strip shape. The distribution of α-Cr phases in the grains is the same as that of σ phases. With the increase in aging time, the number of σ and α-Cr phases is increased and they are gradually coarsened. The σ phases with discontinuous distribution along the grain are gradually connected, and there is a tendency to develop into a network distribution. With the increase in aging time to 2000 h, the strength of the alloy increases first and then decreases, and reaches the peak after aging for 500 h. While, the hardness keeps increasing.
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对整体叶盘材料Ti60钛合金进行激光增材修复,研究其显微组织及力学性能。结果表明,热影响区组织呈现由基体区双态组织向修复区网篮组织的过渡特征,平均宽度约为900 μm。修复区主要由贯穿多个沉积层的外延生长的柱状晶组成,柱状晶内为分布均匀的α相网篮组织。3个区域内均弥散分布着Ti3(Sn, Al)小平面相,尺寸相近,其形貌和含量却因制备工艺凝固速度的不同而差异明显。3个区域硬度相当。拉伸试样断口特征表明激光增材修复Ti60钛合金的断裂机制为混合型断裂,平均抗拉强度和屈服强度分别为992.4和916.6 MPa,优于Ti60钛合金锻件强度标准,断后伸长率和断面收缩率的平均值为8.5%和14.6%,与Ti60钛合金锻件标准相差不大,达到实际工程应用要求。
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The microstructure and mechanical properties of integral bladed titanium alloy Ti60 repaired by laser were studied. The results show that the heat affected zone structure presents the transition characteristics from the dual structure of the matrix area to the mesh basket structure of the repair area, and its average width is about 900 μm. The repair zone is mainly composed of columnar crystals growing epitaxially through multiple sedimentary layers, and the columnar crystals are uniformly distributed by α phase mesh basket structures. Ti3(Sn, Al) facet facies of similar size are dispersed in the structure of the three regions, but their morphology and regional content vary significantly due to the solidification speed of the preparation process. The three areas are equally hard. The fracture characteristics of tensile specimens show that the fracture mechanism of laser additive repaired Ti60 titanium alloy is mixed fracture. The average tensile strength and yield strength are 992.4 and 916.6 MPa, respectively, which are superior to the strength standard of Ti60 titanium alloy forgings. The average elongation and section shrinkage after fracture are 8.5% and 14.6%, respectively, which are similar to the standard of Ti60 titanium alloy forgings and which meet the requirements of practical engineering application.
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为实现对高V、N微合金钢轧制-冷却工艺过程中组织、析出相的精准控制,利用Gleeble-1500D热模拟实验机研究了轧后不同冷速下实验钢的热膨胀曲线、相变规律、过冷奥氏体动态连续冷却转变曲线(动态CCT曲线),并着重研究了微观组织演变行为、显微硬度和纳米碳氮化物析出行为对冷却速率的敏感性。结果表明:冷却速率低于3 ℃/s时,实验钢显微组织由铁素体和珠光体组成;当冷却速率位于3 ℃/s时,发生贝氏体相变,基体组织由铁素体、珠光体和贝氏体组成;冷却速率为8 ℃/s时,珠光体组织消失,马氏体组织开始出现,基体组织由沿晶铁素体、贝氏体和马氏体组成;当冷却速率达到20 ℃/s时,基体组织中马氏体占主,并由少量先共析铁素体和贝氏体组成。此外,冷却速率对纳米碳氮化物的析出行为也具有显著影响,冷速处于1 ℃/s以内时,多边形铁素体中纳米析出相直径和数密度具有较强的冷却速率敏感性,纳米析出相直径随冷速提升显著降低,数密度随冷速提升而提高;冷速由1 ℃/s增加至3 ℃/s时,纳米析出相直径进一步降低,而数密度趋于稳定;当冷速继续增至5 ℃/s时,纳米析出相直径保持稳定,数密度呈现下降趋势。研究还发现,贝氏体组织中纳米析出相较少,贝氏体不利于纳米相析出。基于上述组织演变与析出规律的研究,工业化试制出了屈服强度700 MPa以上、满足抗震要求的高V、N微合金钢。
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In order to achieve precise control of the structure and precipitates during the rolling-cooling process of the high V, N micro-alloyed steel, the Gleeble-1500D thermal simulated test machine was used to study the thermal expansion curve and phase transformation rules of the experimental steel at different cooling rates after rolling. In particular, the dynamic continuous cooling transformation curve (dynamic CCT curve) of supercooled austenite, and the microstructure evolution behavior, microhardness and sensitivity of the nano-sized carbonitride precipitation behavior to the cooling rate were studied. The results show that when the cooling rate is lower than 3 °C/s, the microstructure of the experimental steel is composed of ferrite and pearlite. When the cooling rate is 3 °C/s, bainite transformation occurs, and the matrix structure is composed of ferrite, pearlite and bainite. On the other hand, the pearlite structure disappears, and the martensite structure begins to be formed at the cooling rate of 8 ℃/s, and the matrix structure is composed of intergranular ferrite, bainite and martensite. When the cooling rate reaches 20 °C/s, the matrix structure is dominated by martensite and it is mixed with a small amount of proeutectoid ferrite and bainite. Furthermore, the cooling rate also has a significant influence on the precipitation behavior of nano-sized carbonitrides. When the cooling rate is within 1 °C/s, the diameter and number density of the nanoprecipitates in the polygonal ferrite a show strong sensitivity to the cooling rate. The diameter of the nanoprecipitates is apparently decreased with the increase in cooling rate, and it is inverse for the change in number density. When the cooling rate increases from 1 ℃/s to 3 ℃/s, the diameter of the nanoprecipitates further decreases, and the number density tends to be stable. As the cooling rate is further increased from 3 ℃/s to 5 ℃/s, the diameter of the nanoprecipitates keeps constant, and the number density is decreased. It is also found that less nanoprecipitates are contained in the bainite structure and the bainite is not helpful for the precipitation. Based on the above research on the structure evolution and precipitation law, a high V, N micro-alloyed steel with a yield strength of more than 700 MPa and meeting seismic requirements has been industrialized and trial-produced.
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研究了基板预热温度对选区激光熔化(SLM)制备AlSi9Mg1ScZr合金样品微观组织及力学性能的影响,在35、 85、135 ℃ 3种不同基板预热温度下,制备了SLM样品并分别进行微观组织观察及性能测试。结果表明,基板预热温度设置为135 ℃时,由于基板预热温度和激光扫描热输入的共同影响,使合金在打印过程产生了原位时效效应,在保留细小枝晶和Si网格的同时促进了元素从过饱和固溶体中析出。相比基板预热35 ℃的样品,纳米尺度的Mg2Si相和Si相在α-Al基体及枝晶界析出的数量显著增加,起到了提高强度的作用;但微米尺度富Fe相的析出对塑性产生了负面影响。在基板预热温度设置为135 ℃时,制备的AlSi9Mg1ScZr合金在0°方向上屈服强度高达360 MPa、抗拉强度高达502 MPa、伸长率为7%;90°方向上屈服强度高达331 MPa、抗拉强度高达511 MPa、伸长率为5.4%。本研究通过提高基板预热温度,在SLM过程中实现了SLM样品的原位时效,改善了SLM制备AlSi9Mg1ScZr合金的微观组织,在不经过后续热处理的情况下,大幅降低了残余应力,得到了超高强度的AlSi9Mg1ScZr合金样品。
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The effects of substrate preheating temperature on the microstructure and mechanical properties of AlSi9Mg1ScZr alloy samples prepared by selective laser melting (SLM) were investigated. SLM samples were prepared at three different substrate preheating temperatures of 35, 85, and 135 °C, and subjected to microstructure observation and property testing. The results show that the substrate preheating temperature set to 135 ℃ causes the in-situ aging effect of the alloy during the printing process due to the combined effect of the substrate preheating temperature and laser scanning heat input, which promotes the precipitation of elements from the supersaturated solid solution while retaining fine dendrites and Si lattices. Compared with the sample with the substrate preheated at 35 °C, the nanoscale Mg2Si and Si phases are precipitated significantly more in the α-Al matrix and dendrite boundaries, which improves the strength; however, the precipitation of the micron-scale Fe-rich phase has a negative effect on plasticity. At a substrate preheating temperature setting of 135 °C, the prepared AlSi9Mg1ScZr alloy exhibits a yield strength of 360 MPa, a tensile strength of 502 MPa, and an elongation of 7% in the 0° direction, and a yield strength of 331 MPa, a tensile strength of 511 MPa, and an elongation of 5.4% in the 90° direction. The microstructure of AlSi9Mg1ScZr alloy prepared by SLM is improved by increasing the substrate preheating temperature and in-situ aging of the SLM samples is achieved during SLM, by which the residual stress is significantly reduced and ultra-high strength AlSi9Mg1ScZr alloy samples can be obtained without subsequent heat treatment.
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采用Ag-Cu-Ti钎料及Ag-Cu-Ti+B4C复合钎料对高性能B4C-TiB_2-SiC-TiC(BTST)复合陶瓷进行了钎焊连接,分析了Ag-Cu-Ti钎料在复合陶瓷表面的润湿行为,研究了钎焊温度、保温时间以及B4C含量对接头界面组织及力学性能的影响。结果表明:钎料对BTST复合陶瓷具有良好的润湿性,界面反应主要发生在Ti与复合陶瓷之间,反应产物主要为TiC和TiB。钎焊温度和保温时间显著影响钎焊接头的界面组织和力学性能。随着钎焊温度的提高或保温时间的延长,BTST复合陶瓷侧界面反应层逐渐增厚,钎缝组织趋向于形成Ag-Cu共晶组织,钎焊接头弯曲强度先升高后降低。随着钎料中B4C含量的增加,接头中陶瓷侧反应层厚度急剧降低,钎缝区域组织得到细化,接头强度先升高后降低。当添加B4C颗粒含量(质量分数)为1%,钎焊温度890 ℃,保温时间15 min时,钎焊接头弯曲强度最高为314.2 MPa。
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Ag-Cu-Ti and Ag-Cu-Ti+B4C composite brazing alloys were used to braze the B4C-TiB_2-SiC-TiC (BTST) composite ceramic. The effects of brazing temperature, holding time, and B4C content on the interfacial microstructure and mechanical properties of the joints were investigated. The results show that Ag-Cu-Ti brazing alloy has a good wettability with BTST and Ti reacts with BTST to form TiC and TiB. The thickness of reaction layer increases with the increase in brazing temperature or holding time, and Ag-Cu eutectic alloy forms in the brazing seam. The bending strength of the joints increases first with the brazing temperature or holding time and then decreases. The addition of B4C into the Ag-Cu-Ti refines the microstructure of brazing seam and reduces the thickness of reaction layer. The maximum bending strength of the joint achieved is 314.2 MPa, when the BTST composite ceramic is brazed at 890 ℃ for 15 min by the Ag-Cu-Ti with 1% B4C (mass fraction).
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采用热分解法制备Ti/IrO_2-PbO_2阳极,深入研究硫酸、硝酸、盐酸、草酸、盐酸/草酸蚀刻顺序对Ti/IrO_2-PbO_2阳极性能的影响规律,借助场发射扫描电子显微镜、X射线衍射、循环伏安法、线性扫描伏安法、电化学交流阻抗谱、加速寿命试验等考察钛基体及氧化物涂层的形貌、结构及电化学行为。结果表明:钛基体在双酸中的腐蚀效果优于单酸,获得更致密更均匀的表面结构。双酸腐蚀使钛表面拥有完整的TiHx晶型,有助于提高涂层负载量,增强活性层与基体的结合力。改变双酸蚀刻顺序对阳极电化学性能有一定的影响。草酸/盐酸蚀刻剂处理Ti/IrO_2-PbO_2阳极具有最佳的电催化活性与最长的加速寿命。
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The Ti/IrO_2-PbO_2 anodes were prepared by thermal decomposition. The effects of sulfuric acid, nitric acid, hydrochloric acid, oxalic acid and hydrochloric acid/oxalic acid etching sequence on the performance of Ti/IrO_2-PbO_2 anodes were studied. Surface morphologies, structure and electrochemical behavior of the titanium substrates with oxide-coating were investigated by field emission scanning electron microscope, X-ray diffraction, cyclic voltammetry, linear scanning voltammetry, electrochemical AC impedance spectroscopy and accelerated lifetime test. The results show that dual-acid etching can obtain better corrosion effect and denser and more uniform surface structure compared to single-acid etching. The dual-acid etching achieves a complete TiHx crystal form which is beneficial to increase the coating loading and to enhance the bonding force between the active layer and the substrate. The electrochemical properties of the anode are slightly determined by the order of double acid etching. The Ti/IrO_2-PbO_2 anode treated by oxalic acid/hydrochloric acid shows the best electrocatalytic activity and the longest accelerated lifetime.
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为了提高W形金属密封环的成形质量,对W形金属密封环的超声振动滚压成形过程进行了研究。基于ABAQUS/Explicit有限元仿真软件,搭建了W形金属密封环超声振动辅助滚压成形三维有限元模型,研究了超声频率对环件不均匀变形的影响。结果表明:随着超声频率的增加,环件的应力不均匀度呈现先增后减的规律;环件的应变不均匀度呈现先略微减小,然后激增,再减小的规律;壁厚不均匀度呈现先减小,后增大,再减小的趋势。其中在超声频率为30与40 kHz时环件变形不均匀程度显著增大,这是由于环件产生了起皱现象造成的;通过对截面的应力、应变和壁厚不均匀分析,证明了波峰与波谷位置是成形过程中的关键部位。
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In order to improve the forming quality of W-ring, the ultrasonic vibration rolling process of W-ring was studied. Based on ABAQUS/Explicit finite element simulation software, a three-dimensional finite element model of W-ring with ultrasonic vibration assisted rolling was established, and the influence of ultrasonic frequency on the non-uniform deformation of the ring was studied. The results show that with the increase in ultrasonic frequency, the stress unevenness of the ring increases first and then decreases. The strain unevenness of the ring component decreases slightly first, then increases sharply, and then decreases again. The non-uniformity of wall thickness decreases first, then increases and then decreases. When the ultrasonic frequency is 30 and 40 kHz, the unevenness of the ring deformation increases significantly, which is caused by the wrinkle phenomenon of the ring. By analyzing the stress, strain and wall thickness of the section, it is proved that the position of wave crest and wave trough is the key position in the forming process.
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针对选区激光熔化成形AlSi10Mg铝合金焊接过程中氢气孔敏感性高的问题,采用固溶脱氢与真空固溶脱氢的方法对比了脱氢处理对合金激光焊接接头孔隙缺陷的影响,分析了不同状态下激光焊焊缝气孔分布、组织演变及力学行为。结果表明,固溶处理能够有效减少选区激光熔化成形AlSi10Mg铝合金激光焊焊缝气孔率,且真空固溶处理效果最好,气孔率从沉积态激光焊接焊缝的2.646%降到真空固溶态焊缝的0.14%;通过对接头组织的演变与基板物相形态、成分的变化分析阐述了孔隙出现的原因,揭示了真空热处理是解决由于基板中预先存在的较高含量的氢导致焊缝氢气孔形成的有效方法。固溶后母材硬度明显下降,各试板焊缝的平均硬度(HV)为784 MPa,较为一致;固溶态试板焊接接头抗拉强度为143 MPa,低于沉积态接头,但延伸率增加到了24%,表现为韧性断裂特征。
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Given the high sensitivity of hydrogen porosity in the welding process of AlSi10Mg aluminum alloy formed by selective laser melting, the effect of dehydrogenation treatment on the pore defects of alloy laser welded joints was analyzed by solid solution dehydrogenation and vacuum solid solution dehydrogenation methods under different states as well as the pore distribution, microstructure evolution, and mechanical behavior of laser welded seam. The results show that the solution treatment can effectively reduce the porosity of AlSi10Mg aluminum alloy laser welded seam formed by selective laser melting. Vacuum solution treatment has the best effect, which reduces the porosity from 2.646% of the deposited state laser welding seam to 0.14%. The reasons for the appearance of pores were explained by analyzing the evolution of the joint structure and change in the phase morphology and composition of the substrate. It is revealed that vacuum heat treatment is an effective method to solve the problem of pore formation in the weld due to the high content of hydrogen pre-existing in the substrate. After solid solution, the hardness of the base metal decreases significantly, and the average hardness (HV) of the welds of each test plate is 784 MPa, which is relatively consistent. The tensile strength of the welded joint of the solid solution test plate is 143 MPa, which is lower than that of the deposited joint, but the elongation increases to 24%, showing characteristic of ductile fracture.
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使用Gleeble-1500热力学模拟实验机对TA2纯钛在相变点前后以10 s-1的变形速率进行热压缩变形,研究热压缩对相变的影响。研究发现形变作用在相变点附近时,相变首先发生在板条之间,新形成的β晶粒多为球状或短棒状。随着压缩量的增大,相邻的β晶核逐渐连接并变为条状组织。相变存在临界值,当压缩温度分别为860、890和920 ℃时,压缩量达到40%、30%和20%时,相变趋于饱和,取而代之的是动态再结晶的大量发生。温升效应对相变的影响不大,当变形量较大时温升效应相应提高,动态再结晶数目显著增多,而相变却几乎不发生。温度越高,形变促进相变的现象就越明显,当压缩温度在相变点之后时,很小的压缩量就可以使相变快速发生。
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Gleeble-1500 thermodynamic simulation test machine was used to perform thermal compression deformation on TA2 pure titanium at a deformation rate of 10 s-1 before and after the phase change point, and the influence of thermal compression on the phase transition was studied. It is found that when the deformation is near the phase transition point, the phase transition first occurs between the slats, and the newly formed β grains are mostly spherical or short rod-like. As the amount of compression increases, adjacent β nuclei gradually connect and become strip-like structure. There is a critical value for phase transition. When the compression temperature is 860, 890 and 920 °C and the compression amount reaches 40%, 30% and 20%, respectively, the phase transition tends to saturate, and a large number of dynamic recrystallization occurs. The temperature rise effect has little effect on the phase transition, and when the deformation is large, the temperature rise effect increases correspondingly, and the number of dynamic recrystallization increases signif icantly, but the phase transition hardly occurs. The higher the temperature, the more obvious the phenomenon of deformation promoting phase change. When the compression temperature is after the phase change point, a small amount of compression can make a large number of pha se transitions occur.
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采用电沉积方法在Q235钢上制备Ni-Go复合镀层,研究添加稀土铈对复合镀层形貌、性能的影响。结果表明,当铈浓度为0.8 g·L~(-1)时,得到的复合镀层沉积速率增加到7.142 g·dm-2·h~(-1),硬度(HV)达到5966.24 MPa,磨损量最小,摩擦系数最低为0.387,自腐蚀电位E_(corr)(-0.3993 V)更正,同时腐蚀电流I_(corr)(3.258×10~(-6) A·cm~(-2))最小,腐蚀速率最低,复合镀层的耐腐蚀性能最优。研究发现,加入稀土铈后,Ni-1.0GO复合镀层的类似珊瑚状的微大尺寸的凸聚体变成了尺寸较小的珊瑚珠状的小凸聚体,镀层组织得到明显细化。在铈浓度为0.8 g·L~(-1)时,Ni-1.0GO-0.8RE复合镀层的组织致密性最好,各种性能达到最佳,主要在于稀土铈提高镀液中微粒的分散能力和阴极极化率的效果,提高氢离子在阴极的析出电位,从而抑制析氢反应的发生,使得复合镀层的性能得到进一步提高。
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Ni-Go composite coating was prepared on Q235 steel by electrodeposition. The effect of rare earth cerium on the morphology and properties of the composite coating was studied. The results show that when the cerium concentration is 0.8 g·L~(-1), the deposition rate of the composite coating increases to 7.142 g·dm-2·h~(-1), the hardness (HV) reaches 5966.24 MPa, the wear amount is the smallest, the friction coefficient is the lowest, the self-corrosion potential E_(corr) (-0.3993 V) is corrected, the corrosion current I_(corr) (3.258×10~(-6) A·cm~(-2)) is the smallest, the corrosion rate is the lowest, and the corrosion resistance of the composite coating is the best. After the addition of rare earth cerium, the coral-like micro-sized convex polymer of the Ni-1.0GO composite coating becomes a small coral-like convex polymer with a smaller size, and the coating structure is significantly refined. When the cerium concentration is 0.8 g·L~(-1), the Ni-1.0GO-0.8RE composite coating has the best microstructure consistency and the optimal performance. The main reason is that the rare earth cerium improves the dispersion ability of the particles in the plating solution and the cathodic polarization rate. The effect of increasing the precipitation potential of hydrogen ions at the cathode inhibits the occurrence of hydrogen evolution reaction, which further improves the performance of the composite coating.
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为了进一步拓展金刚石涂层刀具的产业化应用,提升金刚石涂层刀具的结合力性能,本文开展了细晶粒钨钴类硬质合金的化学预处理研究,考察了三步法预处理工艺对不同WC晶粒大小的基体形貌和成分的影响,实现了金刚石涂层与基体的高结合强度。利用扫描电子显微镜和EDS能谱仪对预处理后基体的表面形貌和钴含量以及涂层形貌进行分析,采用拉曼光谱、X射线衍射光谱对涂层物相结构进行分析表征,并采用固体颗粒冲刷测试间接评价金刚石涂层的抗冲刷性能。结果表明:酸处理对Co的去除起着重要作用,WC晶粒越小所需酸处理的时间越长,碱溶液刻蚀WC的速度呈先上升后下降的趋势,碱处理3 min时基体表面暴露的Co含量最多。预处理不仅可以改变基体内部WC和Co的含量,还能改变基体表面的粗糙度,粗糙度的变化与基体表面Co含量的变化规律相一致。由此确定了WC-6%Co(0.2 μm)基体的最佳工艺为A10+M3+A10 s,WC-6%Co(0.4 μm)基体的最佳工艺为A6+M3+A30 s,WC-6%Co(1 μm)基体的最佳工艺为A2+M3+A2。且基体经三步法预处理后沉积的金刚石涂层致密,结晶性较好,抗冲刷性能、结合力性能均优于两步法处理工艺,尤其是WC-6%Co(1 μm)基体上的金刚石涂层抗冲刷性能最好。
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In order to expand the industrial application of diamond coating tool and improve the adhesive strength of diamond coating tool, the “Acid-Murakami-Acid” (AMA) three-step pretreatment process for cemented carbide with different WC grain size of 0.2, 0.4, 1.0 μm was studied. The surface morphology of the pretreated substrate, cobalt content and coating morphology were analyzed by scanning electron microscope and EDS spectrometer. The phase structure of the coating was analyzed and characterized by Raman spectroscopy and X-ray diffraction spectroscopy. The scour resistance of the diamond coating was tested by dynamic impact experiments. The results show that the acid treatment plays an important role in removing Co. The smaller the grain size of WC, the longer the acid treatment time is required. The etching capacity of WC by Murakami treatment increases at first and then decreases, and the maximum Co exposure is reached at 3 min. Pretreatment can not only change the substrate internal WC and Co content, but also change the roughness of the substrate surface, which is consistent with the change rule of substrate surface Co content. Therefore, the best pretreatment process of WC-6%Co (0.2, 0.4, 1.0 μm) substrates were determined. The optimal process for WC-6%Co (0.2 μm) substrate was determined as A10+M3+A10 s, the optimal process for WC-6%Co (0.4 μm) substrate as A6+M3+A30 s, and the optimal process for WC-6%Co (1 μm) substrate as A2+M3+A2. After the three-step method, the substrates obtain uniform and compact diamond coatings, excellent scouring resistance and great adhesion strength, especially the WC-6%Co (1 μm) substrate.
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采用粉末烧结-溶解法成功制备了孔隙率为63%~78%,孔径1.3~2.2 mm的多孔CoCrNi中熵合金,借助SEM和XRD对试样的孔形貌和物相组成进行分析,并对试样进行轴向准静态压缩实验研究。结果表明:多孔CoCrNi中熵合金的弹性模量和屈服平台应力均随孔隙率、孔径的增大而减小;相对孔隙率而言,孔径对力学性能的影响程度较低;不同孔隙率的多孔CoCrNi中熵合金其致密应变下单位体积的能量吸收值为34.81~14.25 MJ/m~3,约为泡沫铝的3.8倍,且5种孔隙率合金的理想吸能效率(I)都接近0.8,说明该多孔CoCrNi中熵合金有潜力成为一种理想的吸能材料。
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The porous CoCrNi medium-entropy alloys with porosity of 63%-78% and pore size of 1.3-2.2 mm were prepared by powder sintering and dissolution method. The pore morphology and phase constitute of the samples were analyzed by SEM and XRD, and the axial quasi-static compression experiments were conducted on the samples. The results show that the elastic modulus and yield platform stress of porous CoCrNi alloy decrease with the increase in porosity and pore size. Compared with porosity, the effect of pore size on mechanical properties is low. The energy absorption value per unit volume in porous CoCrNi medium-entropy alloys with different porosities ranges from 34.81 MJ/m~3 to 14.25 MJ/m~3 under dense strain, which is about 3.8 times larger than that of aluminum foam, and the ideal energy absorption efficiency (I) of the alloys with five kinds of porosities is close to 0.8, indicating that the porous CoCrNi medium-entropy alloy has the potential to become an ideal energy absorption material.
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采用热轧+电脉冲处理的方式实现了Cu-14Sn-0.3Ti合金强度与延伸率的协同提升,Cu-14Sn-0.3Ti合金在经过70%热轧+10 min电脉冲处理后,延伸率由4.7%提升至40%,强度由298 MPa提升至530 MPa。通过调控热轧及电脉冲处理工艺,研究了形变储能,脉冲电流对减少层错,促进孪晶生长的影响。结果表明,Cu-14Sn-0.3Ti合金的强度与密度随着形变储能的增加而提升。在焦耳热和电子风力的共同作用下,Cu-14Sn-0.3Ti合金组织中的δ相发生溶解,层错减少。电脉冲处理后孪晶的形成为位错的运动提供了额外的滑移系,提升了Cu-14Sn-0.3Ti合金的延伸率。一方面孪晶的出现对晶粒进行了分割,细化了晶粒,另一方面,孪晶界的产生阻碍了Cu-14Sn-0.3Ti合金形变时位错的运动,使得Cu-14Sn-0.3Ti合金的强度得到提升。
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The strength and elongation of Cu-14Sn-0.3Ti alloy were improved synergistically by hot rolling+electric pulse treatment. The influence of deformation energy storage and pulse current on reduction of stacking faults and twin growth was investigated by adjusting hot rolling and electric pulse processing. The results show that the elongation of Cu-14Sn-0.3Ti alloy increases from 4.7% to 40%, and the strength increases from 298 MPa to 530 MPa after 70% hot rolling+10 min electric pulse treatment. The strength and density of Cu-14Sn-0.3Ti alloy increase with the increase in deformation energy storage. The δ phase dissolves, and the deformation-induced stacking faults are reduced because of the synergetic effect of Joule heat and electron wind. After electric pulse treatment, the formation of twins provides additional slip systems for the movement of dislocations and improves the elongation of Cu-14Sn-0.3Ti alloy. On the one hand, the appearance of twins divides and refines the grains. On the other hand, the formation of twin boundaries hinders the movement of dislocations during the deformation of Cu-14Sn-0.3Ti alloy, improving the strength of Cu-14Sn-0.3Ti alloy.
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电致变色材料在智能显示和军事伪装等领域具有非常重要的应用前景。为了改善NiO薄膜在碱性电解液中变色响应时间长和循环稳定性差的问题,采用水热法制备了锶离子掺杂纳米片状NiO电致变色薄膜,离子掺杂引起的晶格畸变与微纳结构的协同作用,使NiO薄膜展现出了优异的电致变色性能。锶离子掺杂一方面改善了NiO薄膜的电化学特性,从而缩短了电致变色响应时间(着色时间约为4.5 s,褪色时间约为2.7 s),提高了着色效率(CE, 85.2 cm~2·C~(-1))。另一方面为NiO晶体结构提供了支撑,增强了电致变色过程中晶体结构的稳定性,从而显著提升了薄膜的循环稳定性(循环次数超过了10 000次)。本研究结果对促进电致变色材料的工程化应用具有一定的借鉴和指导意义。
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Electrochromic materials have very important application prospects in the fields of intelligent display and military camouflage. In order to improve the long response time and poor cycling stability of NiO film in alkaline electrolyte, strontium doped nano-sheet NiO electrochromic films were prepared by hydrothermal method. The lattice distortion caused by ion doping and the synergy of micro-nano structure make NiO thin films exhibit excellent electrochromic properties. Strontium ion doping improves the electrochemical characteristics of NiO film, thus improving the electrochromic response time (coloring time is about 4.5 s, bleaching time is about 2.7 s) and the coloration efficiency (CE, 85.2 cm~2·C~(-1)). On the other hand, it provides support for the NiO crystal structure, strengthens the stability of the crystal structure in the electrochromic process, and significantly improves the cycle stability of the film (the cycle number exceeds 10 000). The research results have certain reference and guiding significance to promote the engineering application of electrochromic materials.
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本文综合研究了海洋大气环境下镁合金腐蚀行为的研究进展,比较分析了各种因素对腐蚀行为的影响,对当前研究进展进行总结并对未来研究方向进行展望。在海洋大气环境下,表面薄电解质溶液膜的包覆是镁合金发生电化学腐蚀的主要原因,且多发生局部腐蚀。相比于内陆大气环境,海洋大气中含有较多无机盐气溶胶颗粒,导致点蚀成为主要的局部腐蚀形式。相对湿度的升高会导致薄电解质膜厚度增加,进而加速整体腐蚀速率。随气温上升,镁合金的大气腐蚀速率线性增加,而空气中的CO_2可以抑制NaCl对镁合金的侵蚀。该领域未来需更多关注具体使役环境下合金的腐蚀机理,以及各种环境因素对腐蚀行为的协同作用机制,以指导海洋用镁合金材料的设计和制备。
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The research progress of the corrosion behavior of magnesium alloy in the marine atmospheric environment was reviewed and summarized. The influencing factors on corrosion behavior were analyzed, and some perspectives on future research directions were given. In the marine atmospheric environment, the electrochemical reaction of magnesium alloy coated with thin electrolyte layer on the surface is prone to localized corrosion, and is also susceptible to the influence of environmental factors. Compared to the inland atmospheric environment, the marine atmosphere is rich in aerosol particles, which promote serious pitting corrosion of magnesium alloys. Higher relative humidity can increase the thickness of thin electrolyte layer, resulting in higher atmospheric corrosion rate of the alloy. Meanwhile, the atmospheric corrosion rate of magnesium alloy increases linearly with the increase in temperature. CO_2 in the air can inhibit the erosion of NaCl to magnesium alloys. Future research in this field may focus on the revelation of corrosion mechanism in specific environment and the synergistic effect of various environmental factors on corrosion behavior, so as to guide the design and preparation of marine magnesium alloy materials.
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小型化、多功能电子产品的发展使器件在封装和组装过程中面临热损伤和基板翘曲等问题。为了减小电子封装和组装过程对芯片和器件的热影响,需要研究和开发低熔点的互连材料。锡铋(Sn-Bi)合金钎料由于低熔点、低成本、良好的润湿性和机械强度等特性受到了广泛关注,但是其中脆性Bi相的偏析却不利于器件的长期服役可靠性。通过在Sn-Bi钎料中添加合金元素构成Sn-xBi-yM形式的合金钎料可以有效改善Sn-Bi合金钎料及其焊点的服役可靠性。本文从钎料合金化的角度出发,分析并总结了不同合金元素对Sn-Bi钎料的熔点、润湿性、微观组织、机械性能、界面反应及可靠性的影响。并根据现有的研究成果,展望了锡铋合金钎料未来的发展方向。
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The development of miniaturized and multifunctional electronic products makes the devices face problems such as thermal damage and substrate warpage during the packaging and assembly process. In order to reduce the thermal impact of electronic packaging and assembly processes on chips and devices, low melting point interconnect materials need to be researched and developed. Tin-bismuth (Sn-Bi) alloy solder has received considerable attention due to its low melting point, low cost, good wettability and mechanical strength, but the segregation of the brittle Bi phase is detrimental to the long-term service reliability of the devices. By adding alloying elements to the Sn-Bi solder to form a Sn-xBi-yM alloy solder, the service reliability of the Sn-Bi alloy solder and its solder joints can be effectively improved. The effects of different alloying elements on the melting point, wettability, microstructure, mechanical properties, interfacial reaction and reliability of Sn-Bi solder were analyzed and summarized from the perspective of solder alloying. And based on the existing research results, the future development direction of Sn-Bi alloy solder was prospected.
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强度-塑性倒置普遍存在于传统均匀或随机微观结构的金属材料,而梯度纳米结构材料由于其晶粒尺寸呈梯度变化,变形过程中不同特征尺寸的结构相互协调,使其具有优异的综合力学性能。近年来,由不同性质的非均质区域构成异质结构的设计理论、制备方法和变形机理逐步完善。本文总结了梯度结构、双峰结构、谐波结构、异质层状结构、分散纳米域和层状纳米孪晶结构等异质结构金属材料的分类及制备方法。结合梯度纳米结构金属在应力加载过程中非均匀塑性变形行为,总结其强塑性机制,包括梯度塑性、几何必须位错、机械驱动的晶粒粗化、表面残余应力和表面扰动和剪切带行为等,并讨论其未来发展所面临的挑战。
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The strength-plastic inversion generally exists in the traditional metals with uniform or random microstructure, while the gradient nanostructured metals exhibit excellent comprehensive mechanical properties due to the gradient change of grain size and the coordination of different characteristic sizes during deformation. In recent years, the design theory, preparation method and deformation mechanism of the heterostructures composed of heterogeneous regions with different properties have been gradually improved. In this paper, the classification and preparation methods of heterostructure metals, such as gradient structure, bimodal structure, harmonic structure, heterogeneous layered structure, dispersed nano-domain and layered nano-twin structure, were summarized. Combined with the non-uniform plastic deformation behavior of gradient nanostructured metal during stress loading, the strengthening and toughening mechanisms of gradient nanostructured metal were summarized, including gradient plasticity, geometrically necessary dislocation, mechanically driven grain coarsening, surface residual stress, surface disturbance and shear band behavior, and the challenges of its future development were discussed.
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对湿度的精密监测关系着一些潮解材料的保存,电子仪器的测量精准度等各个方面。高性能湿度传感器在现代工业、农业、医疗等领域均具有广泛的用途。湿度敏感材料包括介电材料、半导体材料、金属材料等。作为一种特殊的含有自发电极化的介电材料,铁电材料在湿敏传感器领域的应用越来越受到人们的关注。理论上,铁电材料的电极化对于表面的极性水分子具有强的吸附作用,同时,表面附着的极性水分子也可以反过来影响铁电材料的铁电极化、介电、电阻抗等性能。因此,铁电材料在高性能湿敏传感器件中具有重要的应用前景,铁电湿敏材料具有灵敏度高、响应快、稳定性好等优点。本文综述了铁电湿敏材料的发展历史和现状,详细总结了铁电材料湿度传感的物理机制。将铁电湿敏材料按类别、性质分为铁电纳米、铁电陶瓷、铁电薄膜、铁电单晶四大部分,分别综述了它们湿敏特性的研究进展及影响湿敏性能的各种因素,以期为未来新型铁电材料的湿敏研究提供一些科学参考。
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The precise monitoring of humidity is related to the preservation of some deliquescent materials, the measurement accuracy of electronic instruments and other aspects. High-performance humidity sensors have a wide range of uses in modern industry, agriculture, and medicine. Humidity sensitive materials include dielectric materials, semiconductor materials, metal materials, etc. Ferroelectric materials are a special kind of dielectric material containing spontaneous electrodes, and their application in the field of humidity-sensitive sensors is receiving increasing attention. Theoretically, the electrodeposition of ferroelectric materials has a strong adsorption effect on the polar water molecules on the surface, and at the same time, the polar water molecules attached to the surface can in turn affect the ferroelectric polarization, dielectric and electrical impedance properties of ferroelectric materials. Therefore, ferroelectric materials have important application prospects in high-performance wet-sensitive sensor devices, and ferroelectric wet-sensitive materials have the advantages of high sensitivity, fast response, and good stability. This paper reviewed the development history and status of ferroelectric moisture-sensitive materials, and summarized the physical mechanism of humidity sensing by ferroelectric materials. The ferroelectric moisture-sensitive materials were classified into four major parts, namely, ferroelectric nano, ferroelectric ceramic, ferroelectric thin film, and ferroelectric single crystal, according to their categories and properties, and the research progress of their moisture-sensitive properties and various factors affecting the moisture-sensitive performance were reviewed, in order to provide some scientific references for the future research of moisture-sensitive of new ferroelectric materials.
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近年来,难熔金属研究的逐步深入,传统工艺难以满足制备难熔金属及其复杂结构的需求。鉴于难熔金属材料的高熔点和优异的高温力学性能,将其与选区激光熔化技术相结合,将为难熔金属的设计提供更大的空间与可加工性。本文对难熔金属材料的选区激光熔化技术进行了总结,按照材料分类,对钨合金、多孔钽、钼合金以及难熔高熵合金进行评述。因为选区激光熔化成型难熔金属过程对合金成分和加工参数等较敏感,故总结了这些因素对工艺控制和零件质量的影响。最后,归纳了当前研究的优势和不足,并对今后的发展趋势进行了展望。
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In recent years, refractory metals have been progressively researched and traditional processes have difficulty in meeting the demands of preparing refractory metals with complex structures. Given the high melting points and excellent high-temperature mechanical properties of refractory metal materials, combining them with selective laser melting technology will provide greater scope and processability for the design of refractory metals. The selective laser melting technology for refractory metal materials was summarized, and tungsten alloys, porous tantalum and molybdenum alloys as well as refractory high entropy alloys were reviewed according to material classification. As the process of selective laser melting of refractory metals is sensitive to alloy composition and processing parameters, the influence of these factors on process control and part quality was summarized. Finally, the strengths and weaknesses of the current research were summarized, and future trends were outlined.
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介绍了2023年度国家自然科学基金委员会工程与材料科学部机械设计与制造学科(工程科学二处)"人才"和"研究"两类项目系列中部分类型项目的申请、评审与资助情况,以及科学基金项目的进展与结题情况,阐述了机械设计与制造学科在科学基金改革探索、加强人才培养和研讨未来发展方向等方面的具体举措,并展望了2024年的主要工作。
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The applications,evaluations,and funding of several types of projects that were classified into the talent and exploratory funding categories at mechanical design and manufacturing discipline(divisionⅡof engineering science)of the National Natural Science Foundation of China in 2023,as well as the research progresses and findings of the executing and finished projects were reviewed.Specific measures of mechanical design and manufacturing discipline were illustrated,such as the reform of scientific fund,talent cultivation,and future research.Finally,a short prospect of the work in 2024 was introduced.
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基于赫兹接触和弹流润滑理论建立了考虑轴箱轴承的轨道车辆模型,研究了轮轨激扰对轴箱轴承的振动特性和油膜刚度特性的影响规律。分别采用MATLAB/Simulink和UM软件建立了轴承动力学模型和轨道车辆模型,通过相互作用力实现二者的耦合关系。模拟了轴承和轮对的典型故障形式,并详细分析了这些故障对轴承的振动特性和润滑特性的影响。研究结果表明:润滑可以有效减小轴承的振动;轴承的局部故障将导致油膜刚度的增大,轴承故障和车轮扁疤都对润滑的影响较为显著;此外,轮轨激扰会降低轴承外圈的振动比率,但是会增大车辆其他部件的振动,对车体的振动几乎无影响。
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An axle box bearings coupled with a railway vehicle model was developed based on Hertz contact and elastohydrodynamic lubrication theory.The effects of wheel-rail excitations on the vibration and oil film stiffness characteristics of axle box bearings were investigated.MATLAB/Simulink and UM were used to establish the bearing dynamic model and the railway vehicle model,respectively.The coupling relationship between the two was realized through the interaction force.The typical fault forms of bearings and wheelsets were simulated,and the impacts of these faults on bearing vibration and lubrication characteristics were analyzed in detail.The results show that lubrication may effectively reduce bearing vibrations.The partial bearing faults may increase the oil film stiffness,and bearing faults and wheel flats have a significant impact on lubrication.In addition,wheel-rail excitations reduce the vibration ratio of the bearing outer ring while increasing the vibration of other vehicle components and little effects on the vibrations of the car body.
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在行星轮系动力学建模中,常以非线性油膜力或线性刚度-阻尼形式考虑其对系统动力学特性的影响,前者仿真精度高但计算成本也高,后者计算效率高却忽略了油膜力和轴颈-轴套偏心量的时变性,仿真精度有限。为此,以2MW级风电齿轮箱为研究对象,建立滑动轴承时变线性刚度-阻尼模型,提出计入轴颈-轴套时变偏心量的滑动轴承附加偏心修正力计算方法;利用行星架销轴-行星轮变形协调关系,将时变线性刚度-阻尼模型与附加偏心修正力进行耦合;建立应用滑动轴承的风电齿轮箱行星轮系动力学模型,对比了工况和轴承参数对模型计算精度与系统动态响应的影响,并通过试验加以验证。研究结果表明,齿轮副动态啮合力波动会使滑动轴承刚度-阻尼系数和附加偏心修正力产生周期性变化;在稳定和瞬态工况下,提出的模型可以很好地预测系统响应,尤其是行星轮振动响应;减小滑动轴承宽径比与间隙、增大输入转矩可以改善系统均载性能。
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In the dynamic modeling of planetary gear trains,the influences of nonlinear oil film forces or linear stiffness damping forms on system dynamics characteristics were often considered.The former had high simulation accuracy but high computational costs,and the latter had high computational efficiency but ignores the time-varying effects of oil film forces and journal sleeve eccentricity,resulting in limited simulation accuracy.Therefore,a 2MW wind turbine gearbox was taken as the research object herein.A time-varying linear stiffness damping model of the journal bearing was established,and a calculation method for the additional eccentricity correction force of the journal bearing considering the time-varying eccentricity of the journal sleeve was proposed.Then,the time-varying linear stiffness damping model was coupled with the additional eccentricity correction force by using the coordination relationship between the carrier-pin and planet.Finally,a dynamic model of the planetary gear trains in wind turbine gearboxes using journal bearings was established,and the effects of operating conditions and bearing parameters on the calculation accuracy and dynamic system responses were compared and verified through experiments.The results indicate that the fluctuation of dynamic meshing force in gear pairs may cause periodic changes in the stiffness damping coefficient and additional eccentricity correction force of journal bearings.The proposed model may effectively predict system responses,especially planetary gear vibration responses,under stable and transient operating conditions.Reducing the width-diameter ratio and gap,increasing input torque may improve the system' s load sharing performance.
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针对大规模等几何拓扑优化(ITO)计算量巨大、传统求解方法效率低的问题,提出了一种基于样条h细化的高效多重网格方程求解方法。该方法利用h细化插值得到粗细网格之间的权重信息,然后构造多重网格方法的插值矩阵,获得更准确的粗细网格映射信息,从而提高求解速度。此外,对多重网格求解过程进行分析,构建其高效GPU并行算法。数值算例表明,所提出的求解方法与线性插值的多重网格共轭梯度法、代数多重网格共轭梯度法和预处理共轭梯度法相比分别取得了最高1.47、11.12和17.02的加速比。GPU并行求解相对于CPU串行求解的加速比高达33.86,显著提高了大规模线性方程组的求解效率。
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An efficient multi-grid equation solving method was proposed based on the h-refinement of splines to address the challenges posed by large-scale ITO computation and low efficiency of traditional solving methods.By the proposed method,the weight information obtained through h-refinement interpolation between coarse and fine grids was used to construct the interpolation matrix of the multi-grid method,thereby enhancing the accuracy of mapping information for both coarse and fine grids and improving computational efficiency.Additionally,a comprehensive analysis of the multi-grid solving process was conducted,culminating in the development of an efficient GPU parallel algorithm.Numerical examples illustrate that the proposed method outperforms existing methods,demonstrating speedup ratios of 1.47,11.12,and 17.02 in comparison to the linear interpolation multi-grid conjugate gradient method algebraic multi-grid conjugate gradient method,and pre-processing conjugate gradient method respectively.Furthermore,the acceleration rate of GPU parallel solution surpasses that of CPU serial solution by 33.86 times,which significantly enhances the efficiency of solving largescale linear equations.
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针对现有糕点切片机切片效率和质量低下的问题,进行基于新型旋转-直线往复机构的切片机设计分析及参数优化。首先对切片机构型设计及椭圆导轨长短径比和转速进行计算,然后进行运动学和静力学分析,接着分别在不同长短径比和转速动力学仿真分析基础上,构建切刀的加速度均值和均方根值三次多项式拟合方程作为目标函数,利用NSGA-Ⅱ遗传算法进行长短径多目标参数优化及转速择优,最后搭建样机完成不同转速对比实验及玉米饼切片性能测试。结果表明,最优长短径和转速分别为190 mm、120 mm和20 r/min,优化后切刀效率提高75%,切刀进刀加速度的最大和平均误差分别减小26%和49%,退刀加速度的最大和平均误差分别减小60%和63%,玉米饼切面整齐美观,验证了设计的可行性。
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Aiming at the problems of low slicing efficiency and quality of the existing pastry slicing machines,the design analysis and parameter optimization of a slicing machine was carried out based on the new rotary-linear reciprocating mechanisms.Firstly,the design of the slicing mechanisms and the calculation of the length-diameter ratio and speed of the elliptical guide rail was carried out.Secondly,the kinematics and the statics analyses were carried out,then,based on the simulation analysis of different aspect ratios and rotational speed dynamics,the cubic polynomial fitting equation of the mean and root mean square value of the cutter acceleration was constructed as the objective function.The NSGA-Ⅱgenetic algorithm was used to optimize the long and short diameter multi-objective parameters,and the rotational speed was selected.Finally,aprototype was built to complete the comparative experiments of different speeds and the performance tests of corn cake slices.The results show that the optimal long and short diameters and rotation speeds are as 190 mm,120 mm and 20 r/min respectively.After optimization,the cutter efficiency is increased by 75%,the maximum and average errors of the cutter feeding acceleration are reduced by 26%and 49%respectively,and the maximum and arerage errors of retract acceleration are reduced by 60%and 63%respectively.The corn cake section is neat and beautiful,which verifies the feasibility of the design.
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镍基高温合金加工残余应力分布状态对产品质量有显著影响,为实现对残余应力的控制,采用仿真与实验结合的方法,研究了工艺参数、刀具参数以及力-热耦合对镍基高温合金残余应力分布的影响。研究结果表明:切削深度的改变会同时影响径向和切向的残余应力;每齿进给量的改变主要影响进给方向残余应力;当转速提高时,温度场作用变强,材料出现软化效应,铣削合力降低,热应力影响逐渐增强。采用参数组合配比的方法得到了最优的配比方案。发动机叶片零件加工实例表明,提出的基于参数优化配比的方法可有效控制镍基高温合金的加工残余应力。
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The distribution of machining residual stress of nickel-based superalloys had a significant influence on the product quality.To achieve the control method of residual stress,the effects of processing parameters,tool parameters and mechanics-thermal coupling on the residual stress distribution of nickel-based superalloys were studied by means of simulation and experiments.It is found that the change of cutting depth will affect the radial and tangential residual stresses at the same time,and the change of feed rate per tooth mainly affects the residual stress in the feed direction.When the rotating speed increases,the temperature field becomes stronger,the materials are softened,the milling forces are decreased,and the thermal stress is gradually increased.The optimal proportioning scheme is obtained by the method of parameter combination proportioning.Taking the machining of engine blade parts as an example,the method based on parameter optimization may effectively control the residual stress of Nickel-based superalloys.
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刷丝与转子涂层相互作用产生的摩擦热效应直接影响刷式密封的密封性能和使用寿命。分析了刷式密封摩擦副之间的摩擦热效应理论,设计搭建了刷式密封摩擦副摩擦热效应实验装置,设计加工了6种不同结构参数与刷丝材料的刷式密封实验件和4种不同涂层材料的摩擦转盘,实验研究了工况参数、结构参数以及不同摩擦副材料对刷式密封摩擦热效应的影响,通过对比分析刷式密封最高温度以及磨损前后摩擦副的磨损形貌及磨损量,获取了刷丝与转子涂层材料的匹配性关系。研究结果表明:刷式密封最高温度会随着摩擦时长的增加先迅速升高后趋于稳定,随着干涉量的增大而升高,干涉量由0.3 mm增大至0.4 mm,刷丝平均最高温升达39.96℃;最高温度随着刷丝束厚度的增加而升高,随着后挡板保护高度的增大而降低;当刷丝材料为钴基高温合金GH605时,最佳转子涂层材料为WC,当刷丝材料为镍基高温合金GH4169时,最佳转子涂层材料为ZrO_2,此两种匹配材料能够在相同工况下产生较低的摩擦热量,且耐磨性能高于其他匹配材料。
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The frictional heating effects caused by the interaction between brush seal wire and rotor coating directly affected the sealing performance and service life of brush seals.The theory of frictional heating effects between brush seal frictional pairs was analyzed.The experimental device of frictional heating effects between brush seal frictional pairs was designed and built.Six brush seal experimental parts with different structural parameters and brush wire materials and four frictional turntables with different coating materials were designed and processed.The effects of working condition parameters,structural parameters and different frictional pair materials on the frictional heating effects of brush seals were studied experimentally.By comparing and analyzing the maximum temperature of brush seals and the wear morphology and wear amount of frictional pairs before and after wear,the matching relationship between brush wire and rotor coating material was obtained.The results show that the maximum temperature of brush seals increases rapidly and then tends to be stable with the increase of friction time,and increases with the increase of interference.When the interference increases from 0.3 mm to 0.4 mm,the average maximum temperature of brush wires rises to 39.96 ℃.The maximum temperature increases with the increase of the brush thickness and decreases with the increase of the rear baffle protection height.When the brush wire material is cobaltbased superalloy GH605,the best rotor coating material is WC;when the brush wire material is nickelbased superalloy GH4169,the best rotor coating material is ZrO_2.These two matching materials may produce lower friction heat under the same working conditions,and the wear resistance is higher than that of other matching materials.
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针对主动磁悬浮轴承系统(AMBs)转子跌落过程中转子与保护轴承碰摩产生巨大冲击、振动和大量摩擦热,易使保护轴承失效的问题,对立式转子跌落到保护轴承过程中的热特性进行了研究,分析了转子跌落对保护轴承造成破坏的主要影响因素,进而提出了一种采用磁控溅射技术在保护轴承关键表面沉积固体润滑薄膜(类石墨碳基薄膜,GLC)的减摩方法,并对镀膜、未镀膜的保护轴承进行了转子跌落试验。研究结果表明:跌落转速为20 000 r/min时,保护轴承的最高温度为210.60℃,出现在转子与轴承内圈端面高速碰摩阶段,该温度超过了轴承钢160℃的回火温度,导致轴承烧伤而失效。在跌落试验中,镀有GLC薄膜的自润滑保护轴承试验后的沟道和端面外观明显优于未镀膜保护轴承,由碰摩发热导致的内圈端面硬度下降也较轻,质心轨迹和轴向位移更加平稳,温升更低,GLC薄膜起到了关键的自润滑和减摩功能,提高了保护轴承的使用寿命和服役可靠性,为解决主动磁悬浮轴承系统中保护轴承易失效而发生重大事故的问题提供了一种思路和方法。
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The rotor of the AMBs and the auxiliary bearing might produce huge impacts,vibrations and friction heat during the rotor falling which was easy to make the auxiliary bearing fail.The thermal characteristics during the vertical rotor drop on auxiliary bearings were studied,and the main factors leading to the auxiliary bearing failure during the rotor falling were analyzed herein.Subsequently,a method of reducing friction was proposed to deposit solid lubricating film(GLC)on the key surfaces of auxiliary bearings by magnetron sputtering technology,and the rotor drop tests of coated and uncoated auxiliary bearings were performed.The results show that the maximum temperature of the auxiliary bearing is as 210.60℃at a drop speed of 20 000 r/min,which appear in the high-speed rubbing stage between the rotor and the inner ring end face of the bearing.The temperature is higher than the tempering temperature of bearing steel of 160℃,which will lead to the failure of the bearing burn.The surface appearance of the channel and end face of the self-lubricating auxiliary bearings coated with GLC film is obviously better than that of the uncoated ordinary auxiliary bearing after the drop tests.The hardness decrease of the inner ring end face caused by friction and heating is lighter,the trajectory of the center of mass and axial displacement are more stable,and the temperature rise is lower.The GLC films play a key role in self-lubrication,wear resistance and friction reduction,the service life and service reliability of the auxiliary bearings are improved.It also provides an idea and method to solve the problems of auxiliary bearing failures easily in AMBs.
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针对可调谐半导体激光器中普遍存在的输出光频率无跳模调谐范围小、扫描频率低、结构复杂等亟待解决的问题,研究了可调谐半导体激光器内部压电驱动系统的动力学特性。基于提高回转精度、降低轴心偏移量的设计目标,提出了一种多叶片并联的星型柔性机构结构。基于Lagrange方程和Duhamel积分,分别建立了压电驱动系统的运动微分方程和振动方程,在此基础上建立了柔性机构的动力学模型并对其结构参数进行了优化。最后,搭建了压电驱动系统动态特性测试平台,测试了压电驱动系统的机械响应特性以及可调谐半导体激光器的输出光可调谐范围。实验结果表明,压电驱动系统一阶固有频率为2187Hz,柔性机构最大轴心偏移量为0.947 mm。在可调谐半导体激光器无跳模调谐性能测试中,当调谐频率为20Hz时,实现了103.5GHz的无跳模调谐范围。
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In view of the ubiquitous problems in tunable diode lasers,such as small tuning range of output optical frequency without mode hopping,low scanning frequency and complex structure,the dynamic characteristics of the internal piezo-based actuated systems of tunable diode lasers were studied.Based on the design goals of improving rotation accuracy and reducing axis offset,a multi-leaf parallel star-shaped flexible mechanism structure was proposed.After that,based on the Lagrange equation and Duhamel integral,the differential equation of motion and the vibration equation of the piezo- based actuated systems were respectively established.Then,the dynamics model of the flexible mechanisms was established and the structural parameters were optimized.Finally,a test platform was built to explore the mechanical response characteristics of the piezo-based actuated systems and the tunable range of tunable diode lasers.The experimental results show that the first-order natural frequency of piezo-based actuated systems is as 2187Hz.The maximum axis offset of the flexible mechanisms is as 0.947 mm.In the mode-hop-free tuning performance tests of tunable diode lasers,a mode-hop-free tuning range of 103.5GHz is achieved at a tuning frequency of 20Hz.
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为研究不同热处理工艺对激光熔覆残余应力的调控作用,利用ANSYS有限元分析软件建立了热力耦合模型,对不同温度(22~900℃)的熔覆前预热处理、不同温度(200~1000℃)的熔覆后退火处理以及熔覆前后协同热处理条件下的激光熔覆316L不锈钢温度场和应力场进行了数值模拟。研究结果表明:预热对熔池温度影响最大,熔池温度随预热温度的增高而增高;退火处理对激光熔覆残余应力的改善效果最好,800℃退火处理可使残余应力减小约50%,其次是熔覆前后协同热处理,可使残余应力减小约35%,预热处理对激光熔覆残余应力有一定改善,其中预热500℃可使残余应力减小约20%。
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In order to study the control effectiveness of different heat treatment processes on the residual stress of laser cladding,a thermo-mechanics coupling model was established by using ANSYS finite element analysis software.The temperature and stress fields during the laser cladding of 316L stainless steel were simulated under the conditions of preheating(22~900℃)before cladding,annealing treatment(200~1000℃)after cladding and combined heat treatment before and after cladding.The results show that preheating has the greatest influence on the temperature of molten pool.The temperature of the molten pool increases with the increase of the preheating temperature.Annealing treatment has the best effect on improving the residual stress of laser cladding,and the residual stress is reduced by about 50%at 800℃.Comparatively,followed by preheating and annealing treatment,the residual stress is reduced by about 35%.In addition,preheating treatment may also effectively adjust the residual stress,with a reduction of 20%at 500℃.
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为进一步提高无人驾驶混合动力汽车轨迹跟踪精度和能耗经济性,提出了一种轨迹跟踪节能控制融合策略。首先,建立车辆运动学模型,采用模型预测控制策略对车辆进行轨迹跟踪控制;在此基础上,以速度为交互变量,提出了一种三阶段动态规划节能控制策略,在线优化最优经济性函数,以降低整车能耗总成本;最后,选择相互独立的纯跟踪轨迹跟踪算法与功率跟随节能控制策略进行比较。结果表明,所提出的轨迹跟踪节能控制融合策略提高了轨迹跟踪效果,降低了整车能耗总成本,轨迹跟踪精度提高了70.47%,纯电动和混合驱动模式下能耗总成本分别下降了4.52%和25.10%。
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In order to further improve unmanned hybrid vehicles trajectory tracking accuracy and energy consumption economy,this paper proposed a trajectory tracking energy-saving control fusion strategy.Firstly,the vehicle kinematics model was established,and the trajectory tracking control of the vehicle was carried out by using the model predictive control strategy.Then,with velocity as the interactive variable,a three-stage dynamic programming energy-saving control strategy was proposed.In this way,the optimal economic function was optimized online to reduce the total cost of energy consumption of the vehicles.Finally,the independent pure pursuit trajectory tracking algorithm and the power following energy-saving control were selected for comparison strategies.The results show that the proposed trajectory tracking energy-saving control fusion strategy improves the trajectory tracking effectvieness and reduces the total cost of vehicle energy consumption.The trajectory tracking errors are reduced 70.47%.The total cost of energy consumption decreases 4.52%and 25.10%in pure electric drive mode and hybrid drive mode,respectively.
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系统性地构建了一体压铸结构的优化方法,基于车身系统超单元模型实现多性能约束下的车身压铸件轻量化设计。首先,缩减复杂的车身系统,针对连续的车体结构,提出了子系统划分原则和方法,分别对各子系统进行超单元缩减,保证车身系统模型的分析精度并提高计算效率,为快速优化奠定基础;其次,同步考虑压铸结构单体性能和车身系统性能,采用折衷规划法归一化静动态子目标并构建综合目标函数,应用层次分析法得到子目标权重系数,进而开展了多模型拓扑优化,确定了加强筋位置分布;进一步地,同步考虑可设计与可制造性,对压铸结构变厚度拔模面进行参数化定义,并在优化过程中施加制造约束,基于构造的组合代理模型完成厚度参数设计。研究结果表明:在保证分析精度的前提下,缩减的车身系统模型可节省97.3%的计算资源;通过优化,在大幅提高车身一体压铸三角梁结构相关性能的同时,可实现轻量化,表明了所提方法的正确性和实用性。
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An optimization method of integrated casting structures was constructed systematically,and based on the super-element model of body system,body casting part lightweight improving with multi-performance constraints was realized.Firstly,complex body systems were reduced,the sub-system division principle and method were proposed for continuous body structure.Super-element reduction of the sub-system was conducted to ensure analysis accuracy and improve calculation efficiency,laying the foundation for rapid optimization.Secondly,performances of casting structures and body systems were considered simultaneously,the compromise programming methods were used to normalize static and dynamic sub-targets and construct the comprehensive objective function,weight coefficients of sub-targets were obtained by analytic hierarchy process(AHP),and then multi-model topology optimization was carried out to determine position distribution of reinforcements.Furthermore,designability and manufacturability were considered simultaneously,parametric definition of variable thickness drawing surface of casting structure was carried out,manufacturing constraints were applied during optimization processes,and then thickness parameter design was completed based on combined surrogate model.The results show that,under the premise of ensuring the analysis accuracy,reduced body system models improve computing efficiency greatly,and save 97.3%of computing resources.Casting triangular beam lightweight may be achieved while improving related performance by conducting structure optimization,which indicates correctness and practicability of the proposed method.
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碳纤维增强聚合物(CFRP)复合材料在水导激光加工后,切缝表面和横截面存在热损伤,这些损伤是影响材料力学性能、降低材料服役性能的重要因素。针对该问题,采用试验方法分析了加工参数对沟槽几何形貌和表面形貌的影响规律,研究了沟槽表面和横截面的热损伤形成机理。研究结果表明:高激光功率、低脉冲频率和低切割速度可有效增大沟槽深度;激光与材料的相互作用和水射流的冲刷作用是形成沟槽表面热损伤的主要原因。在2 mm厚CFRP切割试验中发现:横截面热影响区宽度与纤维排布方向有关,0°碳纤维热影响区宽度最大,45°和135°碳纤维热影响区宽度次之且宽度相近,90°碳纤维热影响宽度最小;另外,提高水射流速度有利于抑制热影响区的扩展,水射流速度由80 m/s提高至120 m/s,最大热影响宽度缩小35.7%。
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After water jet guided laser machining,CFRP exhibited thermal damages on the cut groove surfaces and cross-sections,which was an important factor affecting the material's mechanics properties and reducing the service performance.To address these issues,the influences of machining parameters on the geometric and surface morphology of grooves were analyzed,and the formation mechanism of surface and cross-sectional thermal damages was investigated herein.The results indicate that high laser power,low pulse frequency,and low cutting speed may effectively increase the depth of the grooves.The interaction between the laser and the material,as well as the flushing action of the water jet,are the main reasons for the formation of thermal damages on the groove surface.In the cutting experiment of 2 mm thick CFRP,it is found that the width of the heat affected zones in the cross-sections is related to the arrangement of the fibers.The heat affected zone width is the largest for 0°carbon fibers,followed by 45°and 135°carbon fibers,which have similar widths,and the width is the smallest for 90°carbon fibers.In addition,increasing the water jet velocity is beneficial for suppressing the expansion of the thermal affected zones.When the water jet velocity is increased from 80 m/s to 120 m/s,the maximum width of the thermal affected zones decreases by 35.7%.
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楔横轧因存在芯部损伤累积行为而容易形成芯部疏松缺陷,准确预测芯部损伤形成条件对楔横轧轴类件高性能制造具有重要意义。开展了不同条件下的热拉伸试验,得到了影响材料损伤的主要因素;基于连续损伤力学,提出了耦合温度、应变速率和应力三轴度的损伤本构模型;开展了不同断面收缩率的楔横轧试验,标定了损伤本构模型的材料断裂阈值,并验证了损伤模型的预测精度;利用该模型预测了断面收缩率、展宽角、成形角对芯部损伤的影响规律,为参数选择提供参考。研究结果表明:温度、应变速率及应力三轴度都显著影响材料损伤行为,所建立的耦合损伤本构模型能较好地预测楔横轧芯部的损伤演化过程;楔横轧芯部损伤与成形角成反比,与展宽角和断面收缩率成正比,各参数影响程度由小到大依次为断面收缩率、展宽角、成形角。
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Due to the cumulative central damage behavior in cross wedge rolling,it was prone to form central porosity defects,thus it was of great significance for high-performance manufacturing of cross wedge rolling shaft parts to accurately predict the formation conditions of central damages.The hot tensile tests were conducted under different conditions to obtain the main factors that affected material damages.Subsequently,the coupled damage constitutive models considering temperature,strain rate and stress triaxiality were proposed based on continuous damage mechanics.Furthermore,experiments on cross wedge rolling with different area reduction were conducted to calibrate the material fracture threshold of the damage constitutive model and verify the prediction accuracy of the damage model.The models were used to predict the influence laws of area reduction,spreading angle,and forming angle on central damage,which provided references for parameter selection.The results show that temperature,strain rate and stress triaxiality all significantly affect material damage behavior,and the established coupled damage constitutive models may effectively predict the evolution processes of central damages in cross wedge rolling.The central damages of cross wedge rolling are inversely proportional to the forming angle,and is directly proportional to the spreading angle and area reduction.The degree of influence of each parameters,from small to large,is in order of area reduction,spreading angle,and forming angle.
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铆钉镀层是影响铆接接头成形及力学性能的重要因素,采用单边摩擦铆焊(SSFR)工艺连接6005A-T6和6A01-T5铝合金板材,研究了无镀层、Zn镀层、ZnNi镀层三种类型铆钉对应的SSFR接头成形过程铆接力、能量输入及接头宏微观成形的演化规律,分析了接头中不同位置的镀层剩余厚度及铆钉/板材界面的元素扩散,探究了铆钉镀层对接头拉剪和十字拉伸性能的影响。研究结果表明,镀层的引入降低了铆钉旋转产生的能量输入,从而使铝合金材料的热影响区减小,但能量输入的降低不利于铆钉空腔内铝合金材料间固相连接的形成,导致接头的拉剪和十字拉伸性能下降。与Zn镀层相比,ZnNi镀层的耐磨性较强,在铆钉高速旋转的搅拌摩擦作用下镀层剩余厚度仍超过40%,有助于提高接头的抗腐蚀性能。
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Rivet coating was a key factor influencing the formation and mechanics performances of riveted joints.The SSFR processes were used to join 6005A-T6 and 6A01-T5 aluminum alloy sheets herein.Three types of rivets including non-coated,Zn coated,and ZnNi coated were utilized to study the evolution laws of riveting force,energy input,and formation of the SSFR joints.Moreover,the remaining thickness of the coating layers at different positions in the joints and the diffusion of coating elements at the rivet/sheet interfaces was analyzed,and the influences of the rivet coating on the tensile- shear and cross-tension performances of the joints were investigated.The results indicate that the coating reduces the energy input generated by rivet rotation,thereby reducing the heat-affected zones of aluminum alloy materials.However,the decrease in energy input is not conducive to the formation of solid phase bonding between aluminum alloy materials in the rivet cavity,resulting in a decrease in the tensile-shear and cross-tension performances of the joints.Compared with Zn coating,the ZnNi coating has stronger wear resistance,and the remaining thickness still exceeds 40%after the stirring friction caused by high-speed rotation of rivets,which helps to improve the corrosion resistance of joints.
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为提高跨海大桥上轿车的风致行车安全能力,采用合成风和动网格耦合方法建立了轿车超越集装箱货车的瞬态分析模型,揭示了"风-车-桥"气动交互作用机理及其对轿车气动特性的影响规律。采用五次多项式插值算法建立了超车轨迹规划模型,基于模糊逻辑的双PID控制方法与径向基神经网络的滑模控制方法设计了纵横向协调控制器,开展了轿车超车过程的路径跟踪能力分析及行驶稳定性评价。研究结果表明:风-车-桥的气动干扰大小与行驶车道及位置有显著关系,纵横向协调控制器的路径跟踪控制精度和鲁棒性较好,轿车侧风稳定性提高效果明显。
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To enhance the driving safety caused by cross-wind,the transient analysis model of a car overtaking truck on cross-sea bridge was established using a coupling method of composite wind and moving mesh,and the mechanism of aerodynamic interaction between"wind-vehicle-bridge"in the overtaking processes of a car and the influences on the aerodynamic characteristics of the car were revealed.The overtaking trajectory planning models were developed using a fifth degree polynomial interpolation algorithm,and the longitudinal and lateral coordination motion controllers were developed,using dual fuzzy PID control method for the longitudinal controllers and sliding mode control method of radial basis function network for the lateral controllers.The path tracking capability analysis and driving stability evaluation of the overtaking processes of a car under cross-wind were carried out.The results show that the aerodynamic interference is significantly related to the travelling lanes and positions.The longitudinal and lateral coordination motion controllers have better accuracy and robustness in controlling the path tracking,and the cross-wind stability is significantly improved.
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双层动车组设置较大的二系横向阻尼来抑制一次蛇行引起的共振,而较大的二系横向阻尼会使车辆的横向平稳性变差。针对某型高速双层动车组横向平稳性差的问题,基于车端侧滚减振装置的工作原理建立了车端侧滚减振装置在车体滚摆和摇头运动状态下的数学模型,并将AMEsim软件中建立的减振器仿真模型与台架试验进行验证。最后通过建立车端侧滚减振装置与被试车辆的联合仿真模型,在不改变车辆现有悬挂参数的基础上对车端侧滚减振装置的关键参数进行优化选取。仿真结果表明,车端侧滚减振装置可以在不影响车辆垂向平稳性、保证曲线运行安全性的前提下有效改善双层动车组的横向平稳性。
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Double deck EMUs were equipped with amplifiers for secondary lateral damping to mitigate the vibrations caused by primary hunting behaviour.However,increased secondary lateral damping could negatively impact the lateral ride quality of the vehicles.In order to solve the problem of poor lateral ride quality in high-speed double deck EMUs,a mathematical model of the inter-car rolling damping devices was created by taking into account the working principle of the damper as well as the rolling and yaw state of the carbody,and the simulation models of the damper established in AMEsim software were verified with the bench tests.Finally,the key parameters of the inter-car rolling damping devices were optimized by establishing a co-simulation model between the inter-car rolling damping device and the vehicle model,without changing the existing suspension parameters of the vehicles.The simulation results show that the device may effectively improve the lateral ride quality of the double deck EMUs without affecting the vertical ride quality of the vehicles and ensure the safety of curve operations.
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以减小850吨冷剪机剪切力为研究目的,从冷剪机剪切机理及特点出发,采用正交试验法分析剪切间隙、剪刃倾角、剪切速度、剪刃刀面宽度及剪刃重叠量等参数对剪切力的影响,分别以方差、极差及显著性作为影响因素的指标,并对其进行优先级排序,进而优化剪切参数,减小剪切力。优化剪切参数前后的冷剪机现场试验表明,优化前后冷剪机剪切力的实测值与仿真值误差均在5%以内,仿真结果可靠。采用优化后的剪切参数,冷剪机剪切相同规格钢筋时,上剪刃最大剪切力减小了5.84 kN,减小约13%,下剪刃最大剪切力减小了4.77 kN,减小约9.7%。经车间反馈,使用优化后的剪切参数可大幅延长冷剪机剪刃崩刃和磨损的周期,增长剪刃寿命和提高剪切效率。该研究对提高设备经济性和生产效率具有重要意义,可应用于同类型冷剪机的工程设计。
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In order to reduce the shear force of 850t on cold shears,the shearing mechanism and characteristics of the cold shear were studied,the effects of shear parameters such as shear clearance,blade inclination,shear velocity,blade width and blade overlap on shear force were analyzed by orthogonal test.Variance,range and significance were used as the indexes of influencing factors,and the priority of them were given to optimize the shear parameters and reduce the shear force.The experimental verification of the cold shear before and after the optimization of shear parameters were carried out in the workshops which show that the errors between the measured and simulated values of the shear force of the cold shear before and after optimization were within 5%,which verifies the reliability of the simulation analysis.By setting the optimal shear parameters and shearing the same steel bar,the maximum shear force of the upper shear blade is reduced by 5.84 kN,about 13%.The maximum shear force of the lower shear blade is reduced by 4.77 kN,about 9.7%.Feedbacks from workshops show that the optimization greatly prolongs the period of blade broken and blunt and improves the blade life and shearing efficiency.The results are of great significance for improving the economy and production efficiency of the equipment,and may be applied to the engineering design of the same type of cold shears.
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大数据时代对于高密度大容量的存储技术需求与日俱增。与传统存储技术的按位记录方式不同,全息存储以二维数据页为读写单位,采用三维体存储模式,凭借存储密度高、数据转换速率快、节能安全以及超长期保存等优势,成为海量冷数据存储的有力竞争者。重点介绍了相位调制的同轴全息存储,分析了目前面向全息存储的纠错码研究现状,并详细介绍了一种参考光辅助的低密度奇偶校验LDPC码优化方案。
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In the era of big data,the demand for high-density and large-capacity storage technology is increasing day by day.Unlike traditional storage technologies that record data bit by bit,holographic storage uses two-dimensional data pages as the unit for reading and writing,adopting a three-dimensional volume storage mode.With advantages such as high storage density,fast data conversion rate,energy efficiency,safety,and ultra-long-term preservation,holographic storage is expected to become the strong competitor for mass cold data storage.This paper focuses on phase-modulated collinear holographic storage and analyzes the current research status of error correction codes for holographic storage.A detailed introduction is provided to an reference beam-assisted low-density parity-check (LDPC) code scheme.
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随着以卷积神经网络为代表的深度学习得到广泛应用,神经网络模型中的计算量也急速增长,推动了深度学习加速器的发展。如何针对加速器硬件的体系结构特性进行加速和优化神经网络模型的性能成为研究热点。针对自主设计的多核向量加速器FT-M7004上的VGG网络模型推理和训练算法,分别提出了卷积、池化和全连接等核心算子的向量化映射方法,采用SIMD向量化、DMA双缓冲传输和权值共享等优化策略,充分发挥了向量加速器的体系结构优势,取得了较高的计算效率。实验结果表明,在FT-M7004平台上,卷积层推理和训练的平均计算效率分别达到了86.62%和69.63%;全连接层推理和训练的平均计算效率分别达到了93.17%和81.98%;VGG网络模型在FT-M7004上的推理计算效率超过GPU平台20%以上。
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With the widespread application of deep learning,represented by convolutional neural networks(CNNs),the computational requirements of neural network models have increased rapidly,driving the development of deep learning accelerators.The research focus has shifted to how to accelerate and optimize the performance of neural network models based on the architectural characteristics of accelerators.For the VGG network model inference and training algorithms on the independently designed multi core vector accelerator FT-M7004,vectorized mapping methods for core operators such as convolution,pooling,and fully connected layers are proposed.Optimization strategies,including SIMD vectorization,DMA double-buffered transfer,and weight sharing,are employed to fully exploit the architectural advantages of the vector accelerator,achieving high computational efficiency.Experimental results indicate that on the FT-M7004 platform,the average computational efficiency for convolution layer inference and training is 86.62% and 69.63%,respectively;for fully connected layer inference and training,the average computational efficiency reaches 93.17% and 81.98%,respectively.The inference computational efficiency of the VGG network model on FT-M7004 exceeds that on the GPU platform by over 20%.
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随着大数据与物联网技术的迅猛发展,多维时间序列数据的应用范围变得更加广泛。面对大量的非线性、高维冗余特征的复杂时间序列,传统的时间序列分析方法已经不能很好地解决多维时间序列的复杂高维特征问题,从而导致预测效果欠佳。针对以上问题,通过对遗传算法和Informer模型进行改进,并融合GRU网络,提出了GGInformer模型。该模型不仅可以有效提取多维时间序列的关键特征,而且较好地解决了长程依赖问题。为了验证模型的预测能力,选取了2种实际数据集与3种公共基准数据集进行实验,相比较Informer基准模型,GGInformer模型在5种数据集上的MSE分别降低了22%,13%,20%,23%和38%。实验结果表明,GGInformer模型可以有效解决多维时间序列数据的复杂特征提取问题,并可以进一步提高时序预测能力。
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With the rapid development of big data and Internet of Things (IoT) technologies,the application scope of multidimensional time series data has become increasingly widespread.Faced with a large amount of complex time series data characterized by non-linearity and high-dimensional redundant features,traditional time series analysis methods struggle to effectively address the complexity of multidimensional time series with high-dimensional features,resulting in suboptimal predictive performance.To address these issues,this paper proposes the GGInformer model,which improves upon the Genetic Algorithm and Informer model while incorporating the GRU network.This model not only efficiently extracts key features from multidimensional time series but also effectively addresses long-term dependency issues.To validate the predictive capability of the model,experiments are conducted on two real datasets and three public benchmark datasets,all of which demonstrated superior performance compared to the baseline models.Specifically,compared to the Informer baseline model,the GGInformer model achieves reductions in Mean Squared Error (MSE) values of 22%,13%,20%,23%,and 38% across the five datasets.The experimental results indicate that the GGInformer model can effectively address the complex feature extraction challenges of multidimensional time series data and further enhance time series prediction capabilities.
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