检索结果-南通市图书馆

在线全文

学校读者我要写书评

暂无评论

Editor’s note

chinese Science Bulletin 2009年第16期54卷 2723-2723页

作者： YAO TanDong & TIAN LiDe key laboratory of Tibetan Environment Changes and Land Surface Processes, {2. of Tibetan Plateau research, chinese academy of sciences, Beijing 100085, china state key laboratory of Cryosphere sciences, cold and arid {12. Environment and engineering research {2., chinese academy of sciences, lanzhou 730000, china key laboratory of Tibetan Environment Changes and Land Surface Processes Institute of Tibetan Plateau Research Chinese Academy of Sciences Beijing China state key {2. of Cryosphere sciences Cold and Arid Regions Environment and Engineering Research Institute Chinese Academy of Sciences Lanzhou China

In 1961, the Global Network Isotopes in Precipitation (GNIP) was operated by the IAEA in collaboration with WMO, and over 500 stations across the globe participated in this program. The initial objective of this progr... 详细信息

关键词：环境同位素世界气象组织水文地球化学国际原子能机构大气环流模式气温变化水资源管理全球网络

在线全文

学校读者我要写书评

暂无评论

黄河源区景观格局与生态功能的动态变化

生态学报 2002年第10期22卷 1587-1598页

作者：王根绪郭晓寅程国栋中国科学院寒区旱区环境与工程研究所冻土工程国家重点实验室兰州730000

利用 2.0世纪 70年代、80年代与 90年代三期遥感资料 ,选取有代表性的 9个有关度量景观空间结构与景观异质性的定量指标 ,通过 FRAGSTATS计算方法 ,系统研究了黄河源区景观生态结构与景观格局变化 ,表明在近 30 a来 ,区域景观空间格局... 详细信息

利用 2.0世纪 70年代、80年代与 90年代三期遥感资料 ,选取有代表性的 9个有关度量景观空间结构与景观异质性的定量指标 ,通过 FRAGSTATS计算方法 ,系统研究了黄河源区景观生态结构与景观格局变化 ,表明在近 30 a来 ,区域景观空间格局趋于破碎化和多样化 ,其形成与发展的主要内在因素是高寒稀疏化草原草地、黑土化与杂类草草地和沙化草地等景观类型的迅速发展 ,其景观面积分别增加了 384 .1 6 %、6 6 .6 3%和 4 2.1 .0 9% ;选取景观生物生产力、景观土壤养分、景观植被覆盖度等景观功能的表征参数 ,提出了景观格局动态演变下分析景观功能变化的定量方法及其数学模型。在明确近 30 a来区域景观格局演变特征的基础上 ,研究了黄河源区不同时段不同景观类型间生态功能的转移流动特征及其区域生态环境效应 ,表明 :近 30 a来 ,黄河源区景观功能变化强烈 ;区域景观动态演变将形成区域内部景观功能向减退与增强两个方向的变化 ,两个方向的强度均衡将形成区域整体生态功能的特征。研究区域景观格局的动态变化所引起的区域生态功能演变特征。

关键词：黄河源区景观格局生态功能动态变化

粉土内甲烷水合物形成与分解过程中的水分特征

在线全文

学校读者我要写书评

暂无评论

天然气地球科学 2009年第4期20卷 616-619,626页

作者：张鹏吴青柏王英梅中国科学院寒区旱区环境与工程研究所冻土工程国家重点实验室甘肃兰州730000

用可探测土壤内部水含量变化的pF-meter探头开展了甲烷水合物形成与分解过程中多孔介质内部水含量变化研究,结果表明,该新型研究方法可有效探测实验过程中多孔介质内水含量变化。通过研究指出:水合物生成时会对介质内的水产生吸力,将水... 详细信息

用可探测土壤内部水含量变化的pF-meter探头开展了甲烷水合物形成与分解过程中多孔介质内部水含量变化研究,结果表明,该新型研究方法可有效探测实验过程中多孔介质内水含量变化。通过研究指出:水合物生成时会对介质内的水产生吸力,将水向水合物处抽吸;水合物分解时会释放水,使介质内水含量增大;温度升高会使存于多孔介质内毛细管中的水向下流动;水合物在粉土中的二次形成范围比一次形成范围更大。

关键词：甲烷水合物形成与分解粉土水分

Concentration and seasonal variation of 10Be in surface aerosols of Lhasa,Tibet

在线全文

学校读者我要写书评

暂无评论

Science Bulletin 2010年第23期 2575-2581页

作者： HUANG Jie1,7,KANG ShiChang1,2.SHEN ChengDe3,CONG ZhiYuan1,LIU KeXin4,WANG Wei5 & LIU LiChao6 1 key laboratory of Tibetan Environment Changes and Land Surface Processes,{2. of Tibetan Plateau research,chinese academy of sciences,Beijing 100085,china 2.state key laboratory of Cryospheric Science,chinese academy of sciences,lanzhou 730000,china 3 key laboratory of Isotope Geochronology and Geochemistry,Guangzhou {2. of Geochemistry,chinese academy of sciences,Guangzhou 510000,china 4 state key laboratory of Nuclear Physics and Technology,Peking University,Beijing 100871,china 5 {2. of Plateau Atmosphere and Environment sciences,Tibet Meteorological Bureau,Lhasa 850000,china 6 cold and {32. regions environmental & engineering research {2.,chinese academy of sciences,lanzhou 730000,china 7 Graduate University of the chinese academy of sciences,Beijing 100049,china

Thirty samples of total suspended particles were collected at a site in western part of Lhasa,Tibet from August 2.06 to July *** 10Be concentrations were determined by Accelerator Mass Spectrometer (AMS).Analysis of correlation between 10Be concentrations and meteorological factors revealed that the wet scavenging has little effect on 10Be.10Be can be used as a proxy of transport processes of the upper atmosphere over the Tibetan *** of correlation between 10Be concentrations and NCEP reanalysis data demonstrated that higher 10Be concentrations in spring were probably caused by the atmosphere exchange from stratosphere to troposphere during February to *** 10Be concentrations during August to September were consistent with the synchronous lower O3 values,suggestive of both 10Be and O3 were probably influenced by the atmosphere exchange from troposphere to stratosphere.

关键词： 10Be concentration background value seasonal variation Lhasa

绿洲景观中居民地空间分布特征及其影响因子分析

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

生态学报 2003年第10期23卷 2092-2100页

作者：角媛梅肖笃宁马明国中国科学院寒区旱区环境与工程研究所冻土工程国家重点实验室兰州730000 云南师范大学旅游与地理科学学院昆明650092 中国科学院寒区旱区环境与工程研究所兰州730000

以张掖绿洲居民地为研究对象 ,用景观格局分析软件 FRAGSTATS计算了 5个景观格局指标 ,用GIS计算了形状指数、景观类型空间邻接比例、最邻近指数、最近距离以及居民地的耕作半径 ,借鉴聚落地理学中的居民地分布研究方法 ,分析了居民地... 详细信息

以张掖绿洲居民地为研究对象 ,用景观格局分析软件 FRAGSTATS计算了 5个景观格局指标 ,用GIS计算了形状指数、景观类型空间邻接比例、最邻近指数、最近距离以及居民地的耕作半径 ,借鉴聚落地理学中的居民地分布研究方法 ,分析了居民地的空间格局特征及其影响因子。结果表明 :1耕地是张掖绿洲内的景观基质 ,居民地是绿洲内分布最广、斑块数最多的景观类型 ;居民地的平均斑块面积小、形状简单、聚集度高 ,与耕地的空间邻接长度和数目均最高 ,其空间分布类型存在空间差异 ;2.地是影响居民地分布格局的重要因子。缓冲区分析方法可以从理论上确定居民地的耕作半径 ,耕作半径与居民地的空间分布类型紧密相关 ;3居民地到渠系的平均最临近距离为 2.1 5m,75.6%的居民地中有渠系穿过 ;4居民地分布受中心城市——张掖市的影响程度极其明显 ,两者呈指数相关 ;5景观格局分析、居民地分布研究方法和 GIS空间分析方法的有效结合 ,可以较好的反映居民地的空间分布特征及其影响因子的相关性 ;6借鉴聚落地理学的最近邻点指数具有明确的生态含义。

关键词：绿洲景观居民地空间格局影响因子张掖

Recent advances in precipitation-bias correction and application

在线全文

学校读者我要写书评

暂无评论

research in cold and {2. regions 2009年第3期1卷 193-198页

作者： DaQing Yang 1, NingLian Wang 2. BaiSheng Ye 2. LiJuan Ma 3 1. Water and environmental research Center, University of Alaska Fairbanks, Fairbanks, Alaska 99775-5860, USA. 2. {2. key laboratory of Cryospheric sciences, cold and arid regions environmental and engineering research institute, chinese academy of sciences, lanzhou, Gansu 730000, china. 3. laboratory for Climate Studies, china Meteorological Administration, Beijing 100081, china. Water and environmental research Center University of Alaska Fairbanks state key {2. of Cryospheric sciences Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences

Significant progresses have been made in recent years in precipitation data analyses at regional to global scales. This paper re-views and synthesizes recent advances in precipitation-bias corrections and applications in many countries and over the cold re-gions. The main objective of this review is to identify and examine gaps in regional and national precipitation-error analyses. This paper also discusses and recommends future research needs and directions. More effort and coordination are necessary in the determinations of precipitation biases on large {2. across national borders. It is important to emphasize that bias cor-rections of precipitation measurements affect both water budget and energy balance calculations, particularly over the cold {2..

关键词： precipitation gauge measurement bias correction cold region

Nonlinear Analysis on Space-time Expending of Artificial frozen Wall for Supporting Deep Foundation Pit

在线全文

学校读者我要写书评

暂无评论

Nonlinear Analysis on Space-time Expending of Artificial Fro...

Current developments of research on permafrost engineering and {2. region environment:a report of the 8^(th) International Symposium on Permafrost engineering

第八届国际冻土工程会议

作者： Fujun Niu~1,Huimin Xia~2.Zhiyin Xu~1,Zhanju Lin~1 (1.state key {2. of frozen soil engineering,cold and arid regions environmental and engineering research {12.,CAS,lanzhou,china 73000 2.engineering {12.,University of Science and Technology,Nanjing,china 2.0007)

＜正＞The artificial ground freezing（AGF） technique has significant advantages in supporting deep foundation pit and subway tunnel *** application of AFG technique,Sanger-Sayles formula is convenient to engineering *** method is commonly used in thermal calculation of artificial frozen wall expending based on the solution of Fourier’s thermal equation with the axisymmetric boundary conditions far from the practical *** somewhat unreasonable hypothesis of the temperature distribution adopted in the energy calculation makes the result ***,the formula can only deal with the problems with single value of thermal physical *** this paper,based on finite element method analysis,we develop a computational analysis on the artificially freezing process with nonlinear changing of the thermal physical parameters,and simulate expending of the frozen wall *** general expressions related to engineering design of the soil temperature distribution of the wall,energy exhaust and the general form concerning the energy exhaust during the freezing process are proposed.

关键词： finite element method artificial ground freezing nonlinear properties energy exhaust

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

research in cold and {2. regions 2010年第2期2卷 93-103页

作者： FuJun Niu 1,2.GuoYu Li 1,ShuPing Zhao 1,ShuJuan Zhang 1,YongGuo Zhao 2.HuiJun Jin 1 1.state key {2. of frozen soil engineering,cold and arid regions environmental and engineering research {12.,chinese academy of sciences,lanzhou,Gansu Province 730000,china 2.key {2. of Highway Construction and Maintenance Technology for Permafrost regions of Ministry of Communications,CCCC First Highway Consultants Co.,Ltd.,Xi’an,Shaanxi Province 710068,china state key {2. of frozen soil engineering Cold and Arid Regions Environmental and Engineering Research InstituteChinese Academy of ScieneesLanzhouGansu Province 730000China key laboratory of Highway Construction and Maintenance Technology for Permafrost {2. of Ministry of Communications CCCC First Highway Consultants Co.Ltd.Xi'anShaanxi Province 710068China state key {2. of frozen soil engineering Cold and Arid Regions Environmental and Engineering Research InstituteChinese Academy of ScieneesLanzhouGansu Province 730000China key laboratory of Highway Construction and Maintenance Technology for Permafrost {2. of Ministry of Communications CCCC First Highway Consultants Co.Ltd.Xi'anShaanxi Province 710068China

The Eighth International Symposium on Permafrost engineering was held in Xi’an,china,October *** major topics discussed in the symposium included:permafrost engineering (involving design,construction and evaluation);mitigation of frost hazards in the regions affected by seasonally frozen ground;properties of frozen soils,model development and their applications;frost hazards and periglacial environments in mountain and plateau regions;climatic,environmental and cryospheric changes;and permafrost hydrology,cold regions water resources and land *** papers submitted to the symposium and lectures during the meeting represented some new developments of research on cold region engineering and *** we summarized the works of the symposium in topics including:Permafrost engineering;General geocryology;Properties of frozen soils:model development and their applications;And climatic,environmental and cryospheric *** the symposium,the attendees pointed out that future studies should pay more attention to theoretical study and engineering mechanism study,and also on interaction between climate change and cold region environments and their engineering affects.

关键词： the 8th symposium permafrost engineering cold region environment summarizing

Distribution of δ18O in surface snow along a transect from Zhongshan Station to Dome A,East Antarctica

在线全文

学校读者我要写书评

暂无评论

Distribution of δ18O in surface snow along a transect from ...