检索结果-南通市图书馆

FARMLAND AND URBAN AREA DYNAMICS MONITORING INCHINA USING REMOTE SENSING AND SPATIALSTATISTICS METHODOLOGY

Chinese Geographical Science 2001年第1期11卷 42-49页

作者： LIU Ming-liang, ZHUANG Da-fang, LIU Ji-yuan (Institute of Remote Sensing Applications, the Chinese Academy of sciences, Beijing 100101, P. R. China Institute of Geographical sciences and Natural Resources Research, the Chinese Academy of sciences, Beij Institute of Remote Sensing Applications the Chinese Academy of Sciences Beijing P. R. China Institute of Geographical sciences and Natural Resources Research the Chinese Academy of Sciences Beijing P. R. China

With the need in the global change research project for the land -use/land-cover change information, most international and regional research organization or groups have put amounts of efforts to improve of the dynamics monitoring and database updating techniques. With the pressure on nature environment from increasing population and decreasing farmland be- coming significant more and more in China, the farmland urban dynamics in historical and current times, even the change trends in the future, should be monitored and analyzed serving for regional and national social, economic and environmental sustain- able development in the long future. Based on spatial and temporal series of land -use/land-cover database resources, Chinese Academy of sciences designed a sampling framework for monitoring farmland and urban area dynamics in regional and national level. In order to test the accuracy of the sampling schema for national and regional level, we took two provinces area into overall covered change detecting process with TM images data through being inter’Preted by digitalization on the screen. The result shows that our stratified random sampling schema is suitable for monitoring land -use/land-cover change at national and regional level with quick response, high accuracy and low expenses. The land-use/land-cover change (LUCC) information can update the LUTEA database for global change research during certain period so that the forecasting process and evaluating analysis on land resources and environment under human and natural driving force will get essential data and produce valuable conclusions.

关键词： Land-use/Land-cover change spatial sampling scheme remote sensing

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

The influence of temperature on diurnal and seasonal variations of N_2O flux from agricultural soilis in Guizhou

引用

Chinese Science Bulletin 1999年第S2期44卷 101-102页

作者： XU Wenbin~(1,2), HONG Yetang~1, CHEN Xuhui~3, QIN Song~3 and JIANG Taiming~3 1. State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of sciences, Guiyang 550002, China 2. Institute of Environment and Resources Chemistry, zhejiang university, Hangzhou 310027, China 3. Soil and Fertilizer Institute, Guizhou Academy of Agricultural sciences, Guiyang 550013, China

AGRICULTURAL soils are the major anthropogenic source of N2O, and temperature is one of the importantenvironmental factors controlling production and emission of N2O from soil. This work focuses on the influence of temperature on diurnal and seasonal variations of N2O flux from subtropical agricultural *** was done by seasonal measuring N2O flux and soil temperature at a corn-rape rotation, a soybeanwinter wheat rotation and a fallow field （106°66’E, 26°50’N, 1140 m a.s.1.）, at Soil and Fertilizer Institute, Guizhou Academy of Agricultural sciences. Available nitrogen content of above three fields wasapproximately 0.71%, organic matter content 10.6-12.0 g/kg, clay （<2 μm） content 25.6%-30.0%, and pH was about 7.5 throughout the whole experiment. Measuring period was between 20 Mar.

关键词： N2O flux temperature diurnal variation seasonal variation agricultural soil.

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

Long-Term Impact of Soil Management on Microbial Biomass C, N and P in Rice-Based Cropping System

引用

Pedosphere 2001年第4期11卷 349-357页

作者： GAO YAJUN, HUANG DONGMAI, ZHU PEILI, WANG ZHIMING and LI SHENGXIU Soil and Fertilizer Institute, Jiangsu Academy of Agricultural sciences, Nanjing 210014 (China) College of Resources and Environment, Northwestern Science and Technology university of Agric 江苏省农业科学院土壤肥料所江苏南京 210014 西北农林科技大学陕西杨凌 712100

A 12-year field experiment was conducted to investigate the effect of different tillage methods and fertil- ization systems on microbial biomass C, N and P of a gray fluvo-aguic soil in rice-based cropping system. Five fertilization treatments were designed under conventional tillage (CT) or no tillage (NT) system: no fertilizer (CK); chemical fertilizer only (CF); combining chemical fertilizer with pig manure (PM); combining chemical fertilizer with crop straw (CS) and fallow (F). The results showed that biomass C, N and P were enriched in the surface layer of no-tilled soil, whereas they distributed relatively evenly in the tilled soil, which might result from enrichment of crop residue, organic manure and mineral fertilizer, and surficial development of root systems under NT. Under the cultivation system, NT had slightly greater biomass C, N and P at 0～5 cm depth, significantly less biomass C, N and P at 5～15 cm depth, less microbial biomass C, N and equivalent biomass P at 15 ～30 cm depth as compared to CT, indicating that tillage was beneficial for the multiplica tion of organisms in the plowed layer of soil. Under the fallow system, biomass C, N and P in the surface layer were significantly greater for NT than CT while their differences between the two tillage methods were negligible in the deeper layers. In the surface layer, biomass C, N and P in the soils amended with organic manure combined with mineral fertilizers were significantly greater than those of the treatments only with mineral fertilizers and the control. Soils without fertilizer had the least biomass nutrient contents among the five fertilization treatments. Obviously, the long-term application of organic manure could maintain the higher activity of microorganisms in soils. The amounts of biomass C, N and P in the fallowed soils varied with the tillage methods; they were much greater under NT than under CT, especially in the surface layer, suggesting that the frequent plowing could decrease the

关键词： fertilization microbial biomass C N and P tillage management

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

An improved method for progressive animation models generation

引用

Science China(Information sciences) 2010年第7期53卷 1312-1321页

作者： ZHANG ShiXue1,2, ZHAO JinYu1 & WU EnHua2,3 1Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of sciences, Changchun 130033, China 2Department of Computer and Information Science, university of Macau, Macao, China 3State Key Laboratory of Computer Science, Institute of Software, Chinese Academy of sciences, Beijing 100190, China 1. Changchun Institute of Optics Fine Mechanics and Physics Chinese Academy of Sciences Changchun 130033 China2. Department of Computer and Information Science University of Macau Macao China3. State Key Laboratory of Computer Science Institute of Software Chinese Academy of Sciences Beijing 100190 China

In computer graphics, animated models are widely used to represent time-varying data. And the progressive representation of such models can accelerate the speed of processing, transmission and storage. In this paper, we propose an efficient method to generate progressive animation models. Our method uses an improved curvature sensitive quadric error metric (QEM) criterion as basic measurement, which can preserve more local features on the surface. We append a deformation weight to the aggregated edge contraction cost during the whole animation to preserve more motion features. At last, we introduce a mesh optimization method for the animation sequence, which can efficiently improve the temporal coherence and reduce visual artifacts between adjacent frames. The results show our approach is efficient, easy to implement, and good quality progressive animation models can be generated at any level of detail.

关键词： animation models LOD progressive mesh mesh optimization

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

当前美国提高师资队伍质量的举措

引用

外国教育研究 2005年第12期32卷 67-71页

作者：朱翊缪苗许明中国科技大学现代教育技术中心安徽合肥230001 福建师范大学教育科学与技术学院福建福州350007

当前美国的教学正面临着严重的质量问题。文章从分析其主要原因入手,探讨美国针对该问题的政策取向,以期对我国改革教师报酬制度、创造支持的领导环境、提高教育质量等方面,提供有益的借鉴。

关键词：美国教学教师质量

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

A new interpolation method for Antarctic surface temperature

引用

Progress in Natural Science:Materials International 2009年第12期19卷 1843-1849页

作者： Yetang Wang~(a,b),Shugui Hou~(b,c,*) a Monitoring Centre of Ocean Environment of Shandong Province,Yantai 264006,China b State Key Laboratory of Cryospheric Science,Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of sciences,Lanzhou 73000,China c MOE,Key Laboratory for Coast and Island Development,School of Geographic and Oceanographic sciences,Nanjing university,Nanjing 210093,China [a]Monitoring Centre of Ocean Environment of Shandong Province Yantai 264006 China [b]State Key Laboratory of Cryospheric Science Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou 73000 China [c]MOE Key Laboratory for Coast and Island Development School of Geographic and Oceanographic Sciences Nanjing University Nanjing 210093 China

We propose a new methodology for the spatial interpolation of annual mean temperature into a regular grid with a geographic resolution of 0.01°for Antarctica by applying a recent compilation of the Antarctic temperature data.A multiple linear regression model of the dependence of temperature on some geographic parameters(i.e.,latitude,longitude,and elevation) is proposed empirically,and the kriging method is used to determine the spatial distribution of regional and local deviations from the temperature calculated from the multiple linear regression *** modeled value and residual grids are combined to derive a high-resolution map of surface air temperature. The performance of our new methodology is superior to a variety of benchmark methods(e.g.,inverse distance weighting,kriging, and spline methods) via cross-validation *** simulation resembles well with those distinct spatial features of surface temperature,such as the decrease in annual mean surface temperature with increasing latitude and the distance away from the coast line; and it also reveals the complex topographic effects on the spatial distribution of surface temperature.

关键词： Surface temperature DEM Antarctica

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

中国热带-亚热带地区晚第四纪植被与气候变化

引用

微体古生物学报 2000年第2期17卷 125-146页

作者：郑卓中山大学地球科学系广州510275

根据华南地区第四纪孢粉分析资料 ,中国热带低海拔丘陵地区冰期气候的植被表现为山地雨林垂直植被带的下降 ,而西部山区的山地雨林被常绿 -落叶阔叶混交林和松林所替代。在亚热带地区则以铁杉属、山毛榉属、桦属、冷杉属及其它落叶阔叶... 详细信息

根据华南地区第四纪孢粉分析资料 ,中国热带低海拔丘陵地区冰期气候的植被表现为山地雨林垂直植被带的下降 ,而西部山区的山地雨林被常绿 -落叶阔叶混交林和松林所替代。在亚热带地区则以铁杉属、山毛榉属、桦属、冷杉属及其它落叶阔叶组分的增加为特点。除了末次盛冰期 ( 2 0 - 1 8ka B.P.)沿海平原的植被为稀树草地 ,气候环境凉干。在此之前的多次冰期 -间冰期旋回华南地区主要表现为冷 /热的气候变化 ,而湿度的变化较小 ,西部高原的一些地区冰期的降雨量甚至可能超过间冰期。根据该区冰期 -间冰期垂直植被带的变化估算 ,华南热带 -南亚热带冰期的年均温约下降 4- 6°C。晚冰期以来 ,个别剖面发现仙女木事件。全新世气候最温暖期多在 850 0 - 380 0 a B.P.之间 ,季雨性常绿阔叶林广泛发育 ,海滩红树林面积超过现在。380 0 a B.P.之后 ,在山区发现有较明显的降温事件 ,但在沿海地区气候变化较弱。全新世气温的波动范围在海拔 1 0 0 0 m以上山地可能达到 3°C,而在低地平原地区的波动幅度仅为 1 - 2°C。

关键词：孢粉分析古植被古气候第四纪华南地区

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

RIVER PATTERNS AND SPATIAL AND TEMPORAL TRANSFORMATION MODES

引用

International Journal of Sediment Research 2000年第4期 357-370页

作者： NI Jinren1,4, WANG Suiji2, 4 and WANG Guangqian3,4 (Prof., center for Environmental sciences, Peking university, 100871, Beijing, China Asso. Researcher and DL, Institute of Geographic sciences and Natural Resources Research, CAS, 100101, Beijing, China

Five main modes of spatial transformation of the river patterns and various factors influencing the river systems are discussed in the paper. Representative rivers in China and other countries demonstrate the river pattern transformation in response to some controlling factors. Furthermore, the fluvial processes are studied with historic fluvial deposits in ancient rivers. It is found that there are certain relationships between the modern spatial transformation and the ancient temporal evolution in some river systems. The anastomosing river pattern and its deposits are analyzed with the drilled core samples. Various spatial transformation modes of river patterns have been reported and different temporal evolution modes have been recorded in sediments of the ancient rivers. The braided-meandering transformation, either spatial or temporal, is found to occur more often than other modes. The main factors controlling the spatial transformation and temporal evolution of the river patterns are geotectonic characteristics, sea level fluctuation, climate change, vegetation, composition of sediment in banks and floodplains, flow discharge and sediment load. The order of these factors differs for transformation modes under different conditions.

关键词： Fluvial river pattern Spatial transformation mode Evolution Braided-meandering transformation

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Three industries and water consumption of Beijing

引用

Journal of Environmental sciences 1998年第2期10卷 54-61页

作者： Wang Hong rui Institute of Environmental sciences,Beijing Normal university,Beijing 100875,China Wang Yan Beijing Municipal Research Institute of Environmental Protection,Beijing 100037,China

Beijing has been experiencing a severe shortage of water. At present serious wastes of water resources result from the unreasonable structure of water uses in various industries sectors. The current conditions of the municipal water use structure and its changes in the industrial sectors were analysed and discussed in terms of the indicators, such as direct water use coefficient, complete water use coefficient, water use multiplier and water reuse rate, by taking a year of 1990s as the base year. Some response strategies for water conservation have been studied and the corresponding recommendations were put forward. All of these have provided a basis for coordinating the relationship between aquatic environment and economic growth in this city, establishing a system for rational utilization of water resources, and promoting the implementation of a strategy for sustainable development.

关键词： direct water use coefficient complete water use coefficient water use multiplier water reuse rate.

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

Self-assembly of Bis[2-(2-hydroxyphenyl)- pyridine]Copper(Ⅱ) Induced by C—H…π and π…π Stacking Interaction

引用

Chemical Research in Chinese Universities 2000年第3期16卷 280-282页

作者： LIU Kui (College of Earth sciences, Changchun university of Science and Technology, Changchun 130026, P. R. China) ZHANG Ping, ZHANG Wei xing, YANG Guang di and WANG Yue (Key Laboratory for Supramolecular Structure and Spectroscopy, Jilin Univers 长春科技大学吉林长春 130026 吉林大学超分子结构与谱学开放实验室吉林长春 130023

The control of molecular assembly in the solid state is an important theme of modern chemistry. The activity in the area of supramolecular structures is investigated. The self-assembly of molecules can form well-defined supramolecular structures under the influence of drive forces. The self-assembly properties of Cu(pp)2[pp = 2-(2-hydroxyphenol)-pyridine] are analyzed under different conditions.

关键词： Stacking interaction Cu complex Supramolecular structure

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

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：