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Remote Sensing-based Spatiotemporal Distribution of Grassland Aboveground Biomass and Its Response to Climate Change in the Hindu Kush Himalayan Region

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Chinese Geographical Science 2022年第5期32卷 759-775页

作者： XU Cong LIU wenjun ZHAO Dan HAO Yanbin xia Anquan YAN Nana ZENG Yuan State Key Laboratory of Remote Sensing Science Aerospace Information Research InstituteChinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China School of Ecology and Environmental Sci-ences&Yunnan Key Laboratory for Plateau Mountain Ecology and Restoration of Degraded Environments Yunnan UniversityKun-ming 650091China College of Life Sciences University of Chinese Academy of SciencesBeijing 100049China CAS Center for Excellence in Tibetan Plateau Earth Sciences Chinese Academy of SciencesBeijing 100101China Beijing Yanshan Earth Critical Zone National Research Station University of Chinese Academy of SciencesBeijing 101408China College of Resources and Envir-onment University of Chinese Academy of SciencesBeijing 100049China

The grassland in the Hindu Kush Himalayan(HKH) region is one of the large st and most biodiverse mountain grassland types in the world,and its ecosystem service functions have profound impacts on the sustainable development of the HKH *** the spatiotemporal distribution of grassland aboveground biomass(AGB) accurately and quantifying its response to climate change are indispensable sources of information for sustainably managing grassland ecosystems in the HKH *** this study,a pure vegetation index model(PVIM) was applied to estimate the long-term dynamics of grassland AGB in the HKH region during *** further quantified the response of grassland AGB to climate change(temperature and precipitation) by partial correlation and variance partitioning analyses and then compared their differences with *** results demonstrated that the grassland AGB predicted by the PVIM had a good linear relationship with the ground sampling *** grassland AGB distribution pattern showed a decreasing trend from east to west across the HKH region except in the southern *** 2000 to 2018,the mean AGB of the HKH region increased at a rate of 1.57 g/(m~2·yr) and ranged from 252.9(2000) to 307.8 g/m~2(2018).AGB had a positive correlation with precipitation in more than 80% of the grassland,and temperature was positively correlated with AGB in approximately half of the *** change in grassland AGB was more responsive to the cumulative effect of annual precipitation,while it was more sensitive to the change in temperature in the growing season;in addition,the influence of climate varied at different ***,compared with that of temperature,the contribution of precipitation to grassland AGB change was greater in approximately 60% of the grassland,but the differences in the contribution for each climate factor were small between the two temporal scales at elevations over 2000 *** accurate assessment of the temporal and spatial

关键词： grassland aboveground biomass(AGB) climate change elevation spatiotemporal distribution Hindu Kush Himalayan(HKH)region

白鹤滩旱谷地灰岩爆破碎石颗粒形状及比表面积特征研究

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岩石力学与工程学报 2019年第7期38卷 1344-1354页

作者：李瑞泽卢文波尹岳降于永军陈明夏文俊严鹏武汉大学水资源与水电工程科学国家重点实验室湖北武汉430072 武汉大学水工岩石力学教育部重点实验室湖北武汉430072 中国水利水电第八工程局有限公司湖南长沙410004

在白鹤滩水电站旱谷地料场3个爆堆中随机选取部分粒径为5~1 000 mm灰岩碎石颗粒为研究对象,按形状将其分为5类。利用三维激光扫描仪和自主设计的三维形状特征测量系统得到5种形状爆破碎石颗粒的轮廓投影,采用图像处理技术计算颗粒的形... 详细信息

在白鹤滩水电站旱谷地料场3个爆堆中随机选取部分粒径为5~1 000 mm灰岩碎石颗粒为研究对象,按形状将其分为5类。利用三维激光扫描仪和自主设计的三维形状特征测量系统得到5种形状爆破碎石颗粒的轮廓投影,采用图像处理技术计算颗粒的形状参数并用SPSS软件进行统计分析;分析5种形状爆破碎石颗粒比表面积的变化规律,并绘制旱谷地灰岩爆破碎石颗粒比表面积累计分布曲线。结果表明,爆堆中六面体碎石颗粒占52%,五面体碎石颗粒占17%,四面体碎石颗粒占13%,针片状碎石颗粒占13%,还含有5%不规则多面体碎石颗粒;六面体碎石颗粒最接近球形,五面体和四面体碎石颗粒近似球形;5种形状爆破碎石颗粒的圆度和球度随粒径增加而增加;粒径越小,爆破碎石颗粒的棱角性越丰富;单位体积炸药消耗量为0.37~0.38 kg/m^3时,5种形状灰岩爆破碎石颗粒表面纹理相似;旱谷地灰岩5~1000mm爆破碎石颗粒的比表面积为179.84~3.82mm^2/g;粒径相同时,5种形状碎石颗粒的比表面积差异不明显,总体上爆破碎石颗粒的比表面积随粒径增加呈指数减小;利用级配曲线和比表面积曲线可推求爆破碎石颗粒的比表面积累计分布曲线。

关键词：岩石力学爆破碎石颗粒比表面积三维激光扫描图像分析

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白及锈病病原菌的鉴定及抗锈病资源筛选

广西植物 2024年第6期44卷 1129-1137页

作者：吴巧芬马晓雅夏科路茜刘巧赵志国郑文俊仇硕广西壮族自治区中国科学院广西植物研究所广西植物功能物质与资源持续利用重点实验室广西桂林541006 桂林理工大学旅游与风景园林学院广西桂林541006

为鉴定引起广西种植区白及锈病的病原菌种类且筛选抗锈病的白及资源,该研究对白及锈病病原菌进行分离,并采用形态学和分子生物学的方法对病原菌进行鉴定,同时通过人工接种病原菌法对23份白及进行锈病抗性评价以及筛选抗锈病的白及资源... 详细信息

为鉴定引起广西种植区白及锈病的病原菌种类且筛选抗锈病的白及资源,该研究对白及锈病病原菌进行分离,并采用形态学和分子生物学的方法对病原菌进行鉴定,同时通过人工接种病原菌法对23份白及进行锈病抗性评价以及筛选抗锈病的白及资源。结果表明:(1)从白及感病叶片中分离的锈病病原菌X2夏孢子呈金黄色,卵圆形或椭圆形,大小为(21.43~30.95)μm×(13.10~19.05)μm;冬孢子呈橘红色、红褐色,倒卵形或棍棒状,大小为(17.25~30)μm×(5.5~6.65)μm。(2)把菌株X2全长689 bp的ITS序列(OQ826009)与GenBank已登陆的序列进行相似性分析发现,菌株X2与Coleosporium sp.(KY783686.1)匹配度最高,序列一致性为95.86%,但系统发育树表明,X2与Coleosporium bletiae(MN108161.1,OP363680.1)聚为一类群;结合形态学和分子生物学的方法,鉴定菌株X2为Coleosporium bletiae。(3)人工接种菌株X214 d后,23份白及的病情指数范围在0~70.7之间,并根据病情指数将23份白及划分为6个抗性等级,即表现为免疫的白及1份,病情指数为0;表现为高抗的白及4份,病情指数为1.7~4.7;表现为抗病的白及6份,病情指数为5.6~9.4;表现为中抗的白及5份,病情指数为12.7~18.3;表现为感病的白及5份,病情指数为32.0~49.1;表现为高感的白及2份,病情指数为62.2~70.7。综上认为,表现为免疫和高抗的5份白及(分别来自云南红河、广西恭城、广西百色、贵州遵义、湖北宜昌)病情指数低、抗锈病能力强,可推广应用或作为培育抗锈病优良种质的亲本材料。该研究结果为后续开展白及锈病的有效防治与致病机理研究提供了支撑。

关键词：白及锈病病原菌鉴定鞘锈菌抗病资源

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涉农供应链时间竞争的瓶颈区域及解决机制

经济与管理 2011年第3期25卷 39-44页

作者：夏文俊张晟义西南财经大学工商管理学院四川成都610074 新疆财经大学工商管理学院新疆乌鲁木齐830012

时间已经成为获取竞争优势的源泉。相对于工业连接型供应链,涉农供应链横跨农业、工业和流通业三大环节,其农业生产中特有的"刚性点阵"、"弱刹车机制"与农业物流的复杂性与特殊性使得介于农户与核心企业之间的区域成为制约涉农供应链时... 详细信息

时间已经成为获取竞争优势的源泉。相对于工业连接型供应链,涉农供应链横跨农业、工业和流通业三大环节,其农业生产中特有的"刚性点阵"、"弱刹车机制"与农业物流的复杂性与特殊性使得介于农户与核心企业之间的区域成为制约涉农供应链时间竞争的瓶颈区域,应将时间瓶颈划分为系统型瓶颈和功能型瓶颈,通过虚拟垂直整合机制有效地压缩其整体时间响应周期。

关键词：涉农供应链时间瓶颈区域界面虚拟垂直整合

Low-temperature and flexible strategy to in-situ fabricate ZrSiO_(4)-based ceramic composites via doping and tuning solid-state reaction

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Journal of Advanced Ceramics 2023年第6期12卷 1238-1257页

作者： Bohan Wang Le Fu Junjie Song wenjun Yu Ying Deng Guofu Xu Jiwu Huang Wei xia School of Materials Science and Engineering Central South UniversityChangsha 410083China State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China Shandong Laboratory of Yantai Advanced Materials and Green Manufacturing Yantai 264006China Applied Materials Science Department of Materials Science and EngineeringUppsala UniversityUppsala 75121Sweden

Synthetic zircon(ZrSiO_(4))ceramics are typically fabricated at elevated temperatures(over 1500℃),which would lead to high manufacturing ***,reports about preparing ZrSiO_(4)-based ceramic composites via controlling the solid-state reaction between zirconia(ZrO_(2))and silica(SiO_(2))are *** this work,we proposed a low-temperature strategy to flexibly design and fabricate ZrSiO_(4)-based ceramic composites via doping and tuning the solid-state *** ceramic composites and ZrSiO_(4) ceramics were in-situ prepared by reactive fast hot pressing(FHP)at approximately 1250℃ based on the proposed strategy,i.e.,a ZrSiO_(4)-SiO_(2) dual-phase composite with bicontinuous interpenetrating and hierarchical microstructures,a ZrSiO_(4)-ZrO_(2) dual-phase composite with a microstructure of ZrO_(2) submicron-and nano-particles embedded in a micron ZrSiO_(4) matrix,and ZrSiO_(4) ceramics with a small amount of residual ZrO_(2) *** results showed that the phase compositions,microstructure configurations,mechanical properties,and wear resistance of the materials can be flexibly regulated by the proposed ***,ZrSiO_(4)-based ceramic composites with different properties can be easily fabricated based on different application *** findings would offer useful guidance for researchers to flexibly fabricate ZrSiO_(4)-based ceramic composites at low temperatures and tailor their microstructures and properties through doping and tuning the solid-state reaction.

关键词： zirconia(ZrO_(2))-silica(SiO_(2)) zircon(ZrSiO_(4)) solid-state reaction ceramic composite mechanical properties wear resistance

胞外DNA在急性呼吸窘迫综合征小鼠炎症损伤中的作用

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第三军医大学学报 2018年第13期40卷 1166-1170页

作者：卢尧王凌峰张晗夏文军孙桂香文爱清陆军军医大学(第三军医大学)第三附属医院(野战外科研究所)输血科重庆400042

目的研究脂多糖(lipopolysaccharide,LPS)诱导急性呼吸窘迫综合征(acute respiratory distress syndrome,ARDS)小鼠胞外DNA的生成情况及其对肺部炎症损伤的作用。方法以LPS(6 mg/kg)经鼻气管滴注法建立ARDS模型。40只雄性C57BL/6小鼠按随机数字表法分为对照组、DNaseⅠ组、LPS组和LPS+DNaseⅠ组,每组10只。造模后24 h取肺组织行HE染色观察肺组织病理改变;取支气管肺泡灌洗液(bronchoalveolar lavage fluid,BALF)检测细胞数量,采用超敏荧光核酸染料检测其中双链DNA浓度;采用ELISA检测BALF中白介素-6(interleukin 6,IL-6)、肿瘤坏死因子α(tumor necrosis factorα,TNF-α)和髓过氧化物酶(myeloperoxidase,MPO)浓度。结果 LPS组小鼠肺组织HE染色可见大量中性粒细胞浸润、肺泡结构破坏、肺泡出血及间质水肿,提示LPS诱导ARDS建模成功。LPS组BALF中细胞计数、MPO、IL-6、TNF-α和双链DNA浓度均分别显著高于对照组(P<0.05),LPS+DNaseⅠ组肺损伤评分和炎症指标均较LPS组显著降低(P<0.05)。结论 LPS诱导ARDS小鼠BALF中胞外DNA浓度升高,而DNaseⅠ能够降低ARDS小鼠BALF中DNA浓度,减轻肺部炎症损伤。

关键词：胞外DNA 脂多糖急性呼吸窘迫综合征炎症损伤小鼠

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一种求解承压含水层水文地质参数的新配线法

河海大学学报（自然科学版） 2019年第1期47卷 7-12页

作者：周志芳王萍李雅冰吴建夏文俊王峻方忠强河海大学地球科学与工程学院江苏南京210098 江苏省交通工程建设局江苏南京210004 中设设计集团股份有限公司江苏南京210014

为了能充分利用抽水试验规范所规定的连续性抽水试验数据资料,原位确定承压含水层不同水头降落漏斗范围的渗透系数(K)、导水系数(T)和储水系数(μ*),基于Theis井流公式及叠加原理导出一种流量变化时无量纲形式的承压含水层降深随时间变... 详细信息

为了能充分利用抽水试验规范所规定的连续性抽水试验数据资料,原位确定承压含水层不同水头降落漏斗范围的渗透系数(K)、导水系数(T)和储水系数(μ*),基于Theis井流公式及叠加原理导出一种流量变化时无量纲形式的承压含水层降深随时间变化的解析解,提出一种含有参变量的一组无量纲降深-时间标准曲线及相应的配线方法。将变流量抽水试验得到的降深随时间变化的实测曲线与标准曲线进行配线,选择任一匹配点记录其在标准曲线、实测曲线中的坐标值和配线的参变量值,将这些记录值代入相关公式,确定对应某一流量时承压含水层的水文地质参数。以苏锡常南部高速无锡境内的场地抽水试验为例进行实例验证,运用配线法分阶段完成,最终求得该场地2-3粉土层承压含水层在变流量下的渗透系数分别为5. 12×10-4cm/s、2. 54×10-3cm/s、2. 83×10-3cm/s。

关键词：连续性抽水试验承压含水层 Theis 井流叠加原理参数解析解配线法参变量水文地质参数苏锡常南部高速公路无锡境内场地

High-temperature mechanical properties of as-extruded AZ80 magnesium alloy at different strain rates

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International Journal of Minerals,Metallurgy and Materials 2022年第7期29卷 1373-1379页

作者： wenjun Liu Bin Jiang Hongchen xiang Qing Ye Shengqi xia Siqiang Chen Jiangfeng Song Yanlong Ma Mingbo Yang College of Materials Science and Engineering Chongqing University of TechnologyChongqing 400054China College of Materials Science and Engineering Chongqing UniversityChongqing 400044China Chongqing Tsingshan Industrial Chongqing 402761China

The mechanical properties of as-extruded AZ80 magnesium alloy at temperatures of 450-525℃ and strain rates of 3.0 s^(−1)and 0.15 s^(−1)were investigated by tensile *** ductility of alloy appeared at 500℃ with a strain rate of 0.15 s^(−1),while the zero strength and zero ductility of the alloy were obtained nearly simultaneously at 525℃ with a strain rate of 3.0 s^(−1).The results indicated that the lower strain rate accelerated the arrival of zero *** the temperature increased,the failure mode of the alloy developed from trans-granular fracture to cleavage fracture and then to inter-granular fracture with the feature of sugar-like grains and fusion *** existence of the low-melting composite ofβ-Mg_(17)Al_(12) and Al_(8)Mn_(5) particles segregated near the Mg_(17)Al_(12) phase along grain boundaries were demonstrated to be the reason for the brittle fracturing of the AZ80 alloy at high ***,microstructural evolution at temperatures approaching the solidus temperature was discussed to clarify magnesium alloy’s high temperature deformation mechanism.

关键词： AZ80 magnesium alloy strain rate microstructural evolution Al_(8)Mn_(5)phase fracture morphology

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起重机载荷谱研究综述

港口装卸 2017年第2期 9-12页

作者：魏军郭庆夏文俊武汉理工大学物流工程学院

起重机载荷谱是进行起重机金属结构疲劳剩余寿命估算和可靠性分析的基础性数据。阐述了起重机载荷-时间历程数据获取和统计分析的基本方法以及起重机载荷谱的编制方法,综述了国内外起重机载荷谱的研究现状和成果,提出了起重机载荷谱研... 详细信息

起重机载荷谱是进行起重机金属结构疲劳剩余寿命估算和可靠性分析的基础性数据。阐述了起重机载荷-时间历程数据获取和统计分析的基本方法以及起重机载荷谱的编制方法,综述了国内外起重机载荷谱的研究现状和成果,提出了起重机载荷谱研究的展望。

关键词：起重机载荷谱疲劳剩余寿命