检索结果-南通市图书馆

Progress in Natural Science:Materials International 2002年第10期 80-82+84页

作者： WANG Chao, ZHANG Hong, LIU Zhi, CHENG Suozhong and LU Guonian(1. LARSIS, Institute of remote sensing Applications, Chinese Academy of {2., beijing 100101, china 2. Department of geography, Nanjing normal University, Nanjing 2.0097, china) LARSIS Institute of Remote Sensing Applications Chinese Academy of Sciences Beijing 100101China Department of geography Nanjing Normal University Nanjing 210097 China

SAR interferometry (InSAR) has a high potential for surface displacement mapping in the range from millimeter to meter. In this paper the potential of ERS-1/2.SAR interferometry for mapping subtle land subsidence has been investigated. A time series of ERS-1/2.SAR data from February 1993 to February 2.00 is collected from measurements taken in Suzhou city, Jiangsu Province, china, eight ERS-1/2.SAR images are used to create seven interferograms, and three differential interferograms are produced using the three-pass method, which clearly show the spatial extent of land subsidence. The deformation maps are validated by leveling surveys, the correlation coefficient and standard deviation between them are 0. 943 and 0.1706 respectively. Based on seven benchmarks, the subsidence rates are estimated, the overall trends are in close agreement with InSAR results. The results of study show that for the mapping of land subsidence in urban environments InSAR has a strong potential due to its cost-saving, high res

关键词： SAR interferometry land subsidence Suzhou.

Effects of Amino Acids Replacing Nitrate on Growth,Nitrate Accumulation,and Macroelement Concentrations in Pak-choi (Brassica chinensis L.)

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Pedosphere 2007年第5期17卷 595-600页

作者： WANG Hua-Jing WU Liang-Huan WANG Min-Yan ZHU Yuan-Hong TAO Qin-Nan ZHANG Fu-Suo Ministry of Education Key Laboratory of Environmental Remediation and Ecosystem Health College of Environmental and Resource Sciences Zhejiang University Hangzhou 310029 （China） college of geography and Resource {2. Sichuan Normal University Chengdu 610066 （China） Department of Crop and Soil sciences the Pennsylvania State University （USA） college of Resources and Environment China Agricultural University Beijing 100094 （China）

A hydroponic experiment was carried out to determine the influence of replacing 2.% of nitrate-N in nutrient solutions with 2. individual amino acids on growth, nitrate accumulation, and concentrations of nitrogen （N）, phosphorus （P）, and potassium （K） in pak-choi （Brassica chinensis L.） shoots. When 2.% of nitrate-N was replaced with arginine （Arg） compared to the full nitrate treatment, pak-choi shoot fresh and dry weights increased significantly （P ≤ 0.05）, but when 2.% of nitrate-N was replaced with alanine （Ala）, valine （Val）, leucine （Leu）, isoleucine （Ile）, proline （Pro）, phenylalanine （Phe）, methionine （Met）, aspartic acid （Asp）, glutamic acid （Glu）, lysine （Lys）, glycine （Gly）, serine （Ser）, threonine （Thr）, cysteine （Cys）, and tyrosine （Tyr）, shoot fresh and dry weights decreased significantly （P ≤ 0.05）. After replacing 2.% of nitrate-N with asparagine （Asn） and glutamine （Gin）, shoot fresh and dry weights were unaffected. Compared to the full nitrate treatment, amino acid replacement treatments, except for Cys, Gly, histidine （His）, and Arg, significantly reduced （P ≤0.05） nitrate concentrations in plant shoots. Except for Cys, Leu, Pro, and Met, total N concentrations in plant tissues of the other amino acid treatments significantly increased （P ≤ 0.05）. Amino acids also affected total P and K concentrations, but the effects differed depending on individual amino acids. To improve pak-choi shoot quality, Gln and Asn, due to their insignificant effects on pak-choi growth, their significant reduction in nitrate concentrations, and their increase in macroelement content in plants, may be used to partially replace nitrate-N.

关键词： amino acids growth N P and K nitrate accumulation pak-choi

Regional Summer Temperature Decrease against Global Warming in china, Landform Effect?

在线全文

学校读者我要写书评

暂无评论

Journal of Mountain Science 2007年第1期4卷 86-90页

作者： LU Aigang PANG Deqian HE Yuanqing PANG Hongxi WANG Tianming GE Jianping Ministry of Education Key Laboratory for Biodiversity Science and Engineering College of Life SciencesBeijing Normal University Beijing 100875 China Institute of C-eography Research Weinan Teachers College Weinan 714000 Shaanxi China Cold and Arid Regions Environmental and Engineering Institute Chinese Academy of SciencesLanzhou 730000 Gansu China

The data of 16o national meteorological observatory （NMO） stations with long-term monthly temperature data for china were analyzed in this study to show the basin-centered summer temperature decrease against global warming in the past half century. The summer and winter isotherm structures of 1950s and 1990s worked out by interpolation show the isotherm structure variations： the isotherm structure generally moves northward in winter, but in summer it is characterized with separate high-temperature and low-temperature centers and the isotherm structure moves inward the centers with global warming, indicating that the temperature in the highland areas increases but that in the lowland areas decreases in the summer of the duration. The possible mechanism of the basin-centered temperature decrease in summer is discussed in this paper.

关键词： Isotherm structure seasonal variation summer temperature decrease plateau-basin effect china

Photosynthesis of Populus euphratica and its response to elevated CO2.concentration in an arid environment

在线全文

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2009年第4期19卷 443-451页

作者： Honghua Zhou a,b,c, Yaning Chena,b, Weihong Li a,b, Yapeng Chen a,b, Lixin Fud a Xinjiang Institute of Ecology and geography, Chinese Academy of sciences, 818 South {2. Road, Urumqi, Xinjiang 830011, china b Key Laboratory of Oasis Ecology and Desert Environment, Xinjiang Institute of Ecology and geography, Chinese Academy of sciences, Urumqi 830011, china c Graduate School of Chinese Academy of sciences, {2. 100039, china d college of Natural Resources and Environment Science of Xinjiang Agricultural University, Urumqi 830052. china [a]Xinjiang Institute of Ecology and geography Chinese Academy of Sciences 818 South Beijing Road Urumqi Xinjiang 830011 China [b]Key Laboratory of Oasis Ecology and Desert Environment Xinjiang Institute of Ecology and Geography Chinese Academy of Sciences Urumqi 830011 China [c]Graduate School of Chinese Academy of Sciences Beijing 100039 China [d]College of Natural Resources and Environment Science of Xinjiang Agricultural University Urumqi 830052 China

The photosynthetic characterization of Populus euphratica and its response to the elevated carbon dioxide concentration ([CO2.) were analyzed based on its net photosynthetic rate (Pn), stomatal conductance (gs), intercellular CO2.concentration (Ci), transpiration rate (Tr), and water use effciency (WUE) at different groundwater depths measured by a portable gas exchange system (LI-6400) in the lower reaches of the Tarim River. The results showed that the elevation of [CO2. decreased the gs, and increased the Pn, Ci and WUE of P. euphratica. However, the effects of the elevated [CO2. on gs, Pn, Ci and WUE varied considerably with groundwater depth. The response of photosynthesis to rising [CO2. was stronger at the greater groundwater depth (more than 6 m) than that at the shallower groundwater depth (less than 6 m). The critical groundwater depth required to maintain the normal survival of P. euphratica was less than 6 m. When the groundwater depth increased to more than 6 m, P. euphratica encountered moderate water stress, and the plant suffered severe water stress when the groundwater depth increased to more than 7 m.

关键词： Photosynthesis Populus euphratica Groundwater depth CO2.concentration The lower reaches of the Tarim River

Bi-directional normalized difference vegetation index: concept and application

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2002年第2期 37-41页

作者： LI Xiaowen , GAO Feng , WANG Jindi , YANG Hua, A. STRAHLER and C. SCHAAF( Research Center for remote sensing and Department of {2., beijing normal University, beijing 100875, china Department of {2. and Center for remote sensing, Boston University, Boston MA02.15, USA) Research Center for remote sensing and Department of {2.，beijing normal University，beijing 100875，china Department of geography and Center for remote {2.，Boston University，Boston MA02.15，USA Department of geography and Center for remote {2.，Boston University，Boston MA02.15，USA Research Center for remote sensing and Department of {2.，beijing normal University，beijing 100875，china

The data products of land surface bi-directional reflectance distribution function (BRDF) from the space-borne Polarization and Directionality of the Earth Reflectance (POLDER) of France and the Moderate Resolution Imaging Spectroradiometer (MODIS) of USA are available recently, but the atmospheric correction for meeting the requirement of quantitative remote sensing is still a very difficult problem. This paper presents a concept: bi-directional {2.ized difference vegetation index (Bi-NDVI), in order to consider simultaneously the effects of both land surface BRDF and atmospheric path scattering. An atmospheric quality index is thus defined for satellite multi-angular observations. The quality of MODIS/BRDF data products can be improved notably through iterative inversion weighed by this index.

关键词： bi-directional reflectance normalized difference vegetation index atmospheric correction.

Study　on　the　damage　of　the　“91．7”　rainstorm　in　Sihu　drainage　area　with　remote　sensing　application　technique

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Environmental sciences 1994年第2期6卷 155-163页

作者： Yu Guangming(Department of geography, Central china {2. Univerrity, Wuhan 430070, china)Chen Ping Wu Xuejin Wang Chaonan(Department of geography, Xianning Teachero’ college, Xianning 437005, Hubei Province, china)

In this paper, the water equilibrium and ground truth are analyzed for '91.7' rainstormin Sihu drainage area, Hubei Province, china. The flood and waterlogging situation of ' 91.7'rainstorm in this area are investigated using remote {2., especially the estimation of inundatedarea, the analysis of temporal and spatial characters of this flood and waterlogging damage. Andthe way of flood-trace using remote {2. is explored. At last, the disastroiis conditions are evalu-ated.

关键词： flood and waterlogging damage inundated area remote sensing, rainstorm.

A new method for comprehensive division of mountainous area: taking Huaihua City as an example

在线全文

学校读者我要写书评

暂无评论

Journal of Geographical sciences 2001年第3期11卷 366-373页

作者： HU Bao-qing1, REN Dong-ming2. ZHANG Hong-en1, LIAO Chi-mei3 (1. Changsha Institute of Geotectonics, CAS, Changsha 410013, china 2. Department of Resource and Environmental sciences, {2. normal University, {2. 100875, china 3. Department of Ge Changsha Institute of Geotectonics CAS Department of Resource and Environmental sciences Beijing Normal University Department of geography Guangxi Normal College

This paper summarizes principles and measures of comprehensive division of mountainous areas, as well as clarifies meaning, structure, function and path established for the map and file information visibility system (MFIVS). And then, taking Huaihua City of Hunan Province as an example, and based on the MFIVS means, concrete attempts on regionalization are carried out. The result is relatively objective and accurate, which illuminates that the method is a comprehensive one with the characteristics of concision, applicability and effectiveness.

关键词： comprehensive division regional system of mountainous area map and file information visibility system (MFIVS) comprehensive evaluation of PRED system Huaihua City

在线全文

学校读者我要写书评

暂无评论

东北漫岗黑土区春季冻融期浅沟侵蚀

山地学报 2006年第3期24卷 306-311页

作者：张永光伍永秋刘宝元北京师范大学沙漠与沙区资源研究所北京师范大学环境演变与自然灾害教育部重点实验室北京师范大学地理与遥感科学学院

浅沟侵蚀是东北漫岗黑土区农耕地上常见的水蚀类型,往往对坡耕地造成严重的破坏。2.05年春季,通过对两个小流域浅沟侵蚀的调查测量,发现该区浅沟侵蚀相当严重,两流域分别形成浅沟14条、16条,浅沟总长度分别达3 2.9 m、2.146 m,浅沟密度... 详细信息

浅沟侵蚀是东北漫岗黑土区农耕地上常见的水蚀类型,往往对坡耕地造成严重的破坏。2.05年春季,通过对两个小流域浅沟侵蚀的调查测量,发现该区浅沟侵蚀相当严重,两流域分别形成浅沟14条、16条,浅沟总长度分别达3 2.9 m、2.146 m,浅沟密度分别为908 m/km2.766 m/km2.侵蚀深度分别为0.17 mm、0.16 mm,侵蚀模数分别达181.8 t/km2.173.6 t/km2.2.05年春季两流域浅沟侵蚀期的径流深分别是6.8 mm、7.7 mm。分析表明,研究区在春季表层土壤解冻、地表裸露和存在季节性冻土层的条件下,春季融雪及强降水易造成强烈的浅沟侵蚀。在分布上,浅沟一般位于坡面的中下部,而且多发育在瓦背状坡面的集流水路上。另外,耕作措施对浅沟的形成和发展也有重要影响。

关键词：黑土区强降水冻融浅沟侵蚀

Physico-chemical Characteristics and Environmental Significance of Snow Deposition on Haxilegen Glacier No.51 in Tian Shan,china

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Mountain Science 2011年第3期8卷 484-494页

作者： DONG Zhiwen LI Zhongqin ZHANG Mingjun WANG Feiteng WU Lihua State Key Laboratory of Cryospheric sciences Cold and Arid Regions Environmental and Engineering Research Institute /Tianshan Glaeiological Station CAS Lanzhou 730000 China college of geography and Environment Science Northwest Normal University Lanzhou 730070 China Graduate University of Chinese Academy of sciences Beijing 100049 China

Snow chemistry on the glaciers of alpine regions is a good indicator of atmospheric environmental *** examine snow chemistry in three snowpits at different altitudes on the Haxilegen Glacier No.51,in the Kuitun River source,Tian Shan,china,during July-September 2.04 to *** use correlation analysis,factor analysis and sea-salt tracing methods to examine the characteristics and sources of major ions and mineral dust particles in the *** show that mineral dust particles and major ions in the snow pits vary *** the Asian dust period in springtime,the concentration of mineral dust particles and major ions deposited in snow is high,while the concentration is relatively low during the non-dust period of summer and *** may be caused by dust storm activity in central *** order of major ionic concentrations in the snow packs was determined to be Ca2. > SO42.> NH4+ > NO3-> Cl-> Na+ > Mg2. > K+.Ca2. was the dominant cation;SO42. was the dominant *** find,with the exception of NO3-,that the variabilities of ionic concentrations are highly *** show that the glacier region was significantly affected by dust activity and anthropogenic *** major ions,especially Na+,originate from dust sources of central Asia and from the Ocean,transported by the westerly winds.

关键词： Snow chemistry Mineral dust Environmental significance Haxilegen glacier No. 51 Tian Shan

Wetland changes in Jianghan Plain and simulation with GIS

在线全文

学校读者我要写书评

暂无评论

Journal of Geographical sciences 1998年第3期8卷 116-121页

作者： ZHANG Huanhai Department of geography, Daqing Teacher’s college, Daqing 163716 {2. LIU Haiyan Commission for Integrated Survey of Natural Resources, Chinese Academy of sciences beijing 100101 {2.

Wetland plays an important role in the tempo spatial evolution of climate, biogeochemistry and biodiversity of the terrestrial ecosystems of the earth. To trace the patterns of wetland changes in the past and predict the changing trends in the future in the dimension of human activities is an arduous task for geographers and ecologists. The paper describes how to combine GIS with geo informatics and geography to simulate the wetland changes happened in Jianghan Plain in the middle reaches of the Yantze River in the last 40 years, and presents the results. The environmental implications of the wetland changes are discussed.

关键词： wetland ecosystems biodiversity GIS remote sensing Jianghan Plain.