检索结果-南通市图书馆

Calculating soil moisture by remote sensing and analyzing hydrologic cycle process in the Yellow River basin

Science china(Technological {1.) 2004年第z1期47卷 1-13页

作者： yang shengtian1.& liu changming1. 2 1. school of environmental sciences, Beijing {1. university, Beijing 1.0875, china 2. Institute of Geographic Science and Natural Resources Research, Beijing 1.01.1. china Beijing normal Univ Sch Environm Sci Beijing 100875 Peoples R China Inst Geog Sci & Nat Resources Beijing 100101 Peoples R China

Based on the AVHRR pathfinder remote sensing data, soil moisture, precipitation and evaporation during the period of 1.82—1.98, soil moisture of all layers of soil-profile (0—1.m) in the Yellow River basin over the 1. years are calculated by the remote sensing model of calculating soil water. The Yellow River basin is divided into seven subcatchments as control sections at the location of six hydrologic stations (Lanzhou, Toudaoguai, Longmen, Sanmenxia, Huayuankou and Lijin). After calculating soil moisture and obtaining runoff data and precipitation data, the dynamical features of hydrological cycle in the Yellow River basin are analyzed for the period from 1.82 to 1.88 using water balance method. The conclusions are as follows: It is feasible to calculate the soil water on the macro-scale, in the soil profile with temporal continuity by means of remote sensing and survey in land. Some values of the key water cycle factors in the Yellow River are obtained, which include the annual precipitation of 4000 km3, the evapotranspiration of 3000-3500 km3, and the soil moisture transformation of ?500- 500 km3. Consequently, we analyzed the process of the water cycle in the Yellow River over the 1. years, and the results show that the segment upstream of Lanzhou city is a relatively humid region, and the area of internal waters and the reaches of Shanshan is the most desiccated region. Therefore, the runoff in the depth process is intensive and the runoff-generating process is weak in more arid regions.

关键词： the Yellow River, soil moisture, remote sensing, hydrologic cycle.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Natural eco-environmental evaluation of eastern Qinghai-Tibet Plateau using RS and GIS

引用

Journal of Geographical sciences 2002年第3期12卷 283-288页

作者： yang shengtian, liu changming, yang Zhifeng, SUNRui, ZHOU Xiaodong(1. Inst. of environmental sciences, Beijing normal university, Beijing 1.0875, china 2. Dept. of Resources and environmental Science, Beijing normal university, Beijing 1.0875,china) Inst. of environmental {1. Beijing Normal University 北京 100875 Dept. of Resources and environmental Science Beijing Normal University 北京 100875

The impact of interbasin water transfer on environment is very significant. The affected area of the west route scheme of the South to North Water Transfer Project in china (SNWT) is located in the eastern Tibetan Plateau, where the altitude is high with frigid eco-environment. In this article, remote sensing and GIS are applied to analyze the natural environment and the natural environment index is established to express the natural conditions of the study area. After the natural environment index is divided into four grades and the features of each grade are analysed, some results are obtained for reference in {1. assessment of the west route of SNWT.

关键词： Qinghai-Tibet Plateau environmental assessment remote sensing GIS

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

全球世界自然遗产地的空间分布及潜力区筛选建议

引用

广西植物 2024年第8期44卷 1495-1511页

作者：刘茂徐雪罗娅杨胜天石春茂赵爽廖梦垚贵州师范大学地理与环境科学学院贵阳550025 贵州省喀斯特山地生态环境国家重点实验室培育基地贵阳550025 贵州师范大学生态文明学院贵阳550025 北京师范大学水科学研究院北京100875

世界自然遗产地对于保护生物多样性至关重要。然而,当前世界自然遗产地对生物多样性保护的贡献与差距仍不明晰。为此,该文分析了世界自然遗产地数量和面积的时空变化特征,并识别了当前世界自然遗产地在全球生物多样性重要分布区中的保... 详细信息

世界自然遗产地对于保护生物多样性至关重要。然而,当前世界自然遗产地对生物多样性保护的贡献与差距仍不明晰。为此,该文分析了世界自然遗产地数量和面积的时空变化特征,并识别了当前世界自然遗产地在全球生物多样性重要分布区中的保护空缺,旨在为未来筛选世界自然遗产地潜力区提供参考。结果表明:(1.截至2021.7月,世界自然遗产地共257项,有1.9项以保护生物多样性为主要目的被列入到名录中,占总数的73.54%。(2)在1.9项以保护生物多样性为目的的世界遗产地中,有80项分布在1.个生物多样性超级丰富的国家;89项分布在全球30个生物多样性热点区内;1.4项分布在全球关键生物多样性区;1.0项分布在1.个植被生物群落中。(3)世界自然遗产地数量的空间分布差异主要受到自然环境、经济发展水平、人口分布等因素的共同影响。(4)世界自然遗产地为生物多样性保护作出了重要贡献但仍存在空缺。未来可从3个方向考虑世界遗产地的申报,即列入类别上可扩展不可再生地质类遗址与生物多样性世界遗产地的名单,生物多样性保护上对未受到保护的优先区予以重视并增强有效性保护,地理分布上加强代表性不足的遗址分布数量。以上研究成果对于指导探寻那些具有独特生物多样价值但还尚未列入世界自然遗产保护的区域有重要参考价值。

关键词：世界自然遗产地自然保护地生物多样性潜力区影响因素

来源：

维普期刊数据库

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

The effect of environmental factors on spatial variability in land use change in the high-sediment region of{1.＇s Loess Plateau

引用

Journal of Geographical sciences 2014年第5期24卷 802-814页

作者： LUO Ya yang {1. ZHAO Changsen liu Xiaoyan liu changming WU Linna ZHAQ Haigen ZHANG Yichi State Key Laboratory of Remote Sensing Science School of Geography Beijing Normal University Beijing Key Laboratory for Remote Sensing of Environment and Digital Cities Beijing 100875 China school of Geographic and {1. sciences Guizhou Normal University Guiyang 550001 China Yellow River Conservancy Commission Zhengzhou 450003 China College of Water Science Beijing Normal University Beijing 100875 China Key Laboratory of Land Water Cycle and Surface Processes CAS IGSNRR CAS Beijing 100101 China College of Resource and Environment Engineering Guizhou University Guiyang 550025 China

In areas with topographic heterogeneity, land use change is spatially variable and influenced by climate, soil properties, and topography. To better understand this variability in the high-sediment region of the Loess Plateau in which soil loss is most severe and sediment diameter is larger than in other regions of the plateau, this study builds some indicators to identify the characteristics of land use change and then analyze the spatial variability as it is affected by climate, soil property, and topography. We build two indicators, a land use change intensity index and a vegetation change index, to characterize the intensity of land use change, and the degree of vegetation restoration, respectively. Based on a subsection mean method, the two indicators are then used to assess the spatial variability of land use change affected by climatic, edaphic, and topographic elements. The results indicate that： 1. Land use changed significantly in the period 1.98-201.. The total area experiencing land use change was 42,302 km2, accounting for 22.57%of the study area. High-coverage grassland, other woodland, and forest increased significantly, while low-coverage grassland and farmland decreased in 201. compared with 1.98.2） Land use change occurred primarily west of the Yellow River, between 35 and 38 degrees north latitude. The four transformation types, including （a） low-coverage grassland to medium-coverage grassland, （b） medium-coverage grassland to high-coverage grassland, （c） farmland to other woodland, and （d） farmland to medium-coverage grassland, were the primary types of land use change, together constituting 60% of the area experiencing land use change. 3） The spatial variability of land use change was significantly affected by properties of dryness/wetness, soil conditions and slope gradient. In general, land use changed dramatically in semi-arid regions, remained relatively stable in arid regions, changed significantly in clay-rich soil, remained relatively sta

关键词： spatial variability land use change dryness/wetness soil properties slope gradient the high-sedi-ment region of china's Loess Plateau

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Comprehensive analysis of changes to catchment slope properties in the high-sediment region of the Loess Plateau, 1.78-201.

引用

Journal of Geographical sciences 2015年第4期25卷 437-450页

作者： ZHOU Xu yang {1. liu Xiaoyan liu changming ZHAO Changsen ZHAO Haige ZHOU Qiuwen WANG Zhiwei State Key Laboratory of Remote Sensing Science School of Geography Beijing Normal University BeijingKey Laboratory for Remote Sensing of Environment and Digital Cities Beijing 100875 China school of Land and Resource China West Normal University Nanchong 637009 Sichuan China Yellow River Conservancy Commission Zhengzhou 450003 China College of Water Science Beijing Normal University Beijing 100875 China Key Laboratory of Land Cycle and Surface Processes CAS IGSNRR CAS Beijing 100101 China

To control soil erosion and restore the degraded environment in the Loess Plateau, a large number of measures related to soil and water conservation have been employed that have profoundly affected catchment properties. This study constructed three indicators to characterize changes to the catchment slope, proposed both a method for a regression analysis of adjacent images and a sequence model, and applied multisource remotely sensed images and GIS spatial clustering analysis technologies to extract thematic information and comprehensively analyze the catchment change characteristics. The results indicate that the catchment slope properties changed significantly. At catchment scale, the average values of ARC, DVC and ART were 6.43%, 25.57% and 4.30%, respectively. There were six clustering types of catchment slope property changes. The maximum and minimum of the average similarities of the clustering types were 0.992 and 0.935. Each slope control measures had a distinct effect on catchment slope; the dominating factor of each clustering type was identified as： Type 1. D-VC, Type 2： D-VCLU, Type 3： D-LUVC, Type 4： D-TAVC, Type 5： D-TAC and Type 6： D-MFC. Type 5 and Type 1.covered the largest areas, respectively occupying 37.28% and 31.01.. Catchment slope property changes also had distinct types that depended on their geomorphological conditions. These findings provide a useful basis from which to further study catchment slope hydrological and soil erosion processes.

关键词： catchment slope property slope control measure changes high-sediment region of the Loess Plateau

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Growing Intact Membrane by Tuning Carbon Down to Ultrasmall 0.37 nm Microporous Structure for Confining Dissolution of Polysulfides Toward High-Performance Sodium–Sulfur Batteries

引用

Energy & environmental Materials 2023年第4期6卷 147-156页

作者： Chao Wu Juan Li Lifei liu Heng Zhang Zhuo Zou Wei Sun Fangyin Dai {1. Li State Key Laboratory of Silkworm Genome Biology College of SericultureTextile and Biomass SciencesSouthwest UniversityChongqing 400715China Institute of Materials Science and Devices School of Materials Science and EngineeringSuzhou University of Science and TechnologySuzhou 215011China school of Materials and Energy Southwest UniversityChongqing 400715China College of Chemistry and Chemical Engineering Hainan Normal UniversityHaikou 571158China

Room temperature sodium–sulfur(Na–S)batteries are severely hampered by dissolution of polysulfides into ***,a facile approach is used to tune a biomass-derived carbon down to an ultrasmall 0.37 nm microporous structure for the first time as a cathode in sodium–sulfur *** produced an intact uniform Na2S membrane to greatly confine the dissolution of polysulfides while realizing a direct solid phase conversion for complete reduction of sulfur to Na2S,which delivers a sulfur loading of 1.mg cm−2(50 wt.%),an excellent rate capacity(933 mAh g^(−1.@0.1.A g^(−1.and 41. mAh g^(−1.@2Ag^(−1.),long cycle performance(0.036%per cycle decay at 1.A g^(−1.after 1.00 cycles),and a high energy density for 373 Wh kg^(−1.(0.1.A g^(−1.)based on whole electrode weight(active sulfur loading+carbon),ranking the best among all reported plain carbon cathode-based room temperature sodium–sulfur batteries in terms of the cycle life and rate *** is proposed that the solid Na2S produced in the ultrasmall pores(0.37 nm)can be squeezed out to grow an intact membrane on the electrode surface covering the outlet of the pores and greatly depressing the dissolution effect of polysulfides for the long cycle *** work provides a green chemistry to recycle wastes for sustainable energies and sheds light on design of a unique pore structure to effectively block the dissolution of polysulfides for high-performance sodium–sulfur batteries.

关键词： carbon-sulfur composite cathode membrane pore size sodium-sulfur batteries

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

RNA-seq profiling the transcriptome of secondary seed dormancy in canola(Brassica napus L.)

引用

Chinese Science Bulletin 2014年第32期59卷 4341-4351页

作者： Fuxia liu Xiangqiang Zhao Lihua Zhang Tang Tang {1. Lu Guiming Chen Xinlong Wang Cuiping Bu Xiangxiang Zhao Jiangsu Key Laboratory for Eco-Agricultural Biotechnology around Hongze Lake Huaiyin Normal University school of Life {1. Nantong University Plant science department South Dakota State UniversityBrookings SD 57006 USA Genetic Engineering and GMO Biosafety Lab of Oil Crops Research Institute Chinese Academy of Agricultural Sciences

Secondary seed dormancy(SSD)is responsible for volunteer plants in canola fields,which causes a series of problems in canola production and serves as an important trait for the environmental safety assessment of transgenic canola.A canola cultivar with strong SSD was used to establish insight into seed transcriptomes in its secondarily dormant seeds and control seeds without dormancy by RNA-seq analysis,aiming to determine the molecular ecological characterizations of SSD.A dataset(more than 4 Gb)of valid sequences was obtained from each sample,which was combined to carry out the de novo *** assembled sequences consisted of 31.,261.ragments with length[1.0 bp,including 29,740 long transcripts of length C 500 *** annotation indicated that 1.641.long transcripts could be categorized into 24 cluster of orthologous groups of proteins(COGs)and 1.,51. transcripts were linked to 2,648 gene ontology(GO)*** were 452 long transcripts with significantly different expression identified by a threshold of[2-fold expression change(P\0.001.between samples,among which 343 transcripts were unambiguously homologous to Arabidopsis *** plant hormones abscisic acid and gibberellins were known as the pivotal regulators of seed dormancy and *** genes responsible for either biosynthesis or signaling of each hormone could be widely verified from the SSD transcriptome,theirs expression evidences failed to correlate with the induction of *** on the enriched terms of gene ontology and KEGG orthology,as well as the expression models of candidate genes of SSD,we proposed that fatty acid metabolism might implicate in SSD in *** information reported here may play a significant role in further understanding of environmental safety assessment of SSD in transgenic canola.

关键词：种子休眠转录物油菜田二级 Q分析转基因油菜双低油菜籽基因本体论

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

生态水文学兴起:学科理论与实践问题的评述

引用

北京师范大学学报（自然科学版） 2022年第3期58卷 412-423页

作者：刘昌明刘璇于静洁杨胜天赵长森门宝辉赵志龙王红瑞北京师范大学水科学研究院城市水循环与海绵城市技术北京市重点实验室北京100875 中国科学院地理科学与资源研究所陆地水循环及地表过程重点实验室北京100101 中国科学院大学北京100049 华北电力大学水利与水电工程学院北京102206

生态水文学是20世纪后半叶发展起来的新兴水科学研究领域的交叉综合学科,基于习近平总书记的“生态优先、绿色发展”理念和实现我国生态文明建设目标,其研究成为我国新时期水科学理论与实践的新目标与新挑战,为“绿色-高质量-可持续”... 详细信息

生态水文学是20世纪后半叶发展起来的新兴水科学研究领域的交叉综合学科,基于习近平总书记的“生态优先、绿色发展”理念和实现我国生态文明建设目标,其研究成为我国新时期水科学理论与实践的新目标与新挑战,为“绿色-高质量-可持续”发展提供强大动力.本文简述了生态水文学国内外发展历程和动向,深入评述了生态水文研究的几个基础理论问题,主要包括:人-水-生态系统关系认知与协同变化的和谐内涵、四大平衡的协同内涵及Budyko水-热平衡联系方程、绿水在生态系统中的重要内容和面向全球变化的生态水文宏微观尺度研究,并着重阐述了生态系统的需水与用水;针对生态水文的实践应用,阐述了水-碳循环耦合机制研究能够有效服务国家“双碳”计划,分析了南水北调工程和黄河流域生态环境治理中生态水文问题,提出了南水北调西线工程是构建国家水网、缓解黄河流域水资源短缺的重要举措;基于生态水文研究现状和国家发展需求,对生态水文研究提出展望,如生态系统对人类活动和气候变化响应机制研究、水土保持与生态建设综合技术体系、多源信息融合新技术、加强与社会科学的交叉融合研究和生态水文系统研究等.

关键词：生态水文人-水-生态系统生态需水黄河流域水碳耦合

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

基于均一化序列的贵州高原1.60-201.年气温时空变化特征分析

引用

水资源与水工程学报 2021年第2期32卷 81-89页

作者：赵志龙罗娅杨胜天余军林刘洋石春茂徐雪贵州师范大学地理与环境科学学院贵州贵阳550025 山东省菏泽第一中学山东菏泽274000 贵州师范大学生态文明学院贵州贵阳550025 北京师范大学水科学研究院北京100875 贵州省水利科学研究院贵州贵阳550001

基于均一化处理后的1.60-201.年贵州高原34个气象站的日均气温资料,利用Mann-Kendall检验、启发式分割算法、极点对称模态分解方法(ESMD)等方法对贵州高原不同时空尺度下的气温变化规律进行研究。结果表明:1.60-201.年贵州高原气温显著... 详细信息

基于均一化处理后的1.60-201.年贵州高原34个气象站的日均气温资料,利用Mann-Kendall检验、启发式分割算法、极点对称模态分解方法(ESMD)等方法对贵州高原不同时空尺度下的气温变化规律进行研究。结果表明:1.60-201.年贵州高原气温显著升高,呈现“非线性、非平稳、跳跃式”的上升特征,气温倾向率为0.1.1.℃/1.a,并在1.97年发生突变;1.98-201.年出现与全球增温“停滞”相一致的升温减缓现象;春夏秋冬四季气温均检测到突变,秋冬季气温对全年升温的贡献最大,夏季最小;空间上呈现全域升温的态势,其中第Ⅱ阶梯对整个区域的贡献率最大;四季气温变化的分布与全年类似,除春季外的季节均呈自西向东3级阶梯升温倾向率减小的格局。研究结果对于贵州高原提高应对全球气候变暖的能力具有现实意义,可为该地区合理利用水热资源、制定可持续发展战略提供决策支持。

关键词：气温时空变化均一性启发式分割算法极点对称模态分解方法(ESMD) 贵州高原

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

全球不同气候带陆地植被净初级生产力变化趋势与可持续性

引用

生态学报 2023年第9期43卷 3729-3743页

作者：徐雪罗娅杨胜天陆晓辉周秋文刘茂石春茂廖梦垚贵州师范大学地理与环境科学学院贵阳550025 贵州省喀斯特山地生态环境国家重点实验室培育基地贵阳550025 北京师范大学水科学研究院北京100875

分析全球不同气候带陆地植被净初级生产力(NPP)的变化趋势与可持续性,对于估算全球陆地生态系统的结构、功能和碳源(汇)具有重要意义。运用Mann-Kendall突变检验、Theil-Sen斜率估计、Hurst指数分析全球不同气候带陆地NPP的变化趋势与... 详细信息

分析全球不同气候带陆地植被净初级生产力(NPP)的变化趋势与可持续性,对于估算全球陆地生态系统的结构、功能和碳源(汇)具有重要意义。运用Mann-Kendall突变检验、Theil-Sen斜率估计、Hurst指数分析全球不同气候带陆地NPP的变化趋势与可持续性。结果表明:(1.全球陆地NPP有明显的地域分异规律,呈现低纬高、高纬低,沿海高、内陆低的特点。约48.79%陆地生态系统的植被NPP得到了改善,其中显著改善的面积占全球陆地生态系统的8.45%,主要分布在北美洲北部和中部、亚马逊河流域西部、刚果盆地、欧洲南部、印度半岛西北部、中国黄土高原;轻微改善的面积占全球陆地生态系统的40.34%,主要分布在南美洲中南部、亚洲东部和澳大利亚大陆东部。(2)各气候带NPP变化趋势和突变点表现为:热带、亚热带、极地带的NPP呈不显著下降趋势(R^(2)=0.1.1.P=0.1.6;R^(2)=0.1.4,P=0.1.0;R^(2)=0.002,P=0.854),热带无明显突变点,亚热带突变点为201.年,极地带突变点为2005年;干旱气候带的NPP呈不明显上升趋势(R^(2)=0.036,P=0.450),突变点为2009年;温带寒温带的NPP呈显著的上升趋势(R^(2)=0.533,P=0.001.,突变点为201.年。(3)各气候带NPP与降水、气温的关系为:干旱气候带、极地带NPP为水分限制型,热带、温带寒温带NPP为热量限制型,亚热带NPP受气温、降水影响不显著。(4)在未来一段时间内,全球陆地NPP呈减少的面积(51.31.)大于增加的面积(48.69%)。其中,干旱气候带、亚热带、温带寒温带的NPP呈减少的面积明显大于增加的面积,将是防止NPP退化工作的重点区域。以上研究结果可为国内外同行对比分析全球不同气候带陆地生态系统的碳源(汇)功能提供参考。

关键词：植被净初级生产力变化趋势可持续性气候带

来源：

维普期刊数据库

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：