检索结果-南通市图书馆

Simulating the transfer and fate of hexachlorocyclohexane in recent 50 years in beijing, china

Science china Earth Sciences 2005年第12期48卷 2203-2213页

作者： CAO Hongying1, LIANG Tao1 & TAO Shu2.1. Institute of Geographical Sciences and Natural Resources Research, chinese Academy of Sciences, beijing 100101, {2. 2. Laboratory for Earth Surface Processes, Peking University, beijing 100871, {2. Institute of Geographical Sciences and Natural Resources Research Chinese Academy of Sciences Beijing China Laboratory for Earth Surface Processes Peking University Beijing China

Taking beijing as a study area, a dynamic fugacity model was used to simulate the transfer and fate of technical HCHs according to the physic-chemical properties of the studying environment and HCH isomers. Dynamic changes of the transfer fluxes and concentrations of HCH isomers during 1952.2.03.were simulated and the model results suggest good agreement between the calculated and measured concentrations of HCH isomers. During 1952.1983. the average input and output amount of HCHs through agricultural application and degradation are 13. t and 150 t respectively. The dominant transfer processes of HCHs in the study area are air-soil deposition, soil erosion and soil-air diffusion, transfer fluxes of these processes are 80 t?a?1, 16 t?a?1 and 11 t?a?1, which account for 92. of total transfer fluxes of HCHs isomers. There were approximately 2.3. HCHs in all environmental compartments of the study area during this period and 97% of which existed in soil compartment. Air and water advection became the dominant input sources of HCHs after 1984 when the application of technical HCHs was prohib-ited, concentration of HCHs quickly descended to a quite low level in several years. Total amount of HCHs isomers remaining in the study area environment now is less than 5% that before 1983. and this percentage may descend to 0.5% after 2. years by prediction.

关键词： fugacity model, hexachlorocyclohexane, compartment, transfer flux, fate.

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

Floating Population Increase and Its Influence on the Urban Population Situation:A Case Study in beijing

引用

chinese Journal of Population,Resources and Environment 2005年第1期3卷 27-35页

作者： Wu Peilin 1,2.& Lu Qi 2.1. Shandong University of Technology, Zibo Shandong 2.5049, {3. 2. Institute of Geographical Sciences and Natural Resources Research, chinese Academy of Sciences, {2., {3. Shandong University of Technology Zibo Shandong 255049 China Institute of Geographical Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China

Floating population is a special population group in china resulting from the implementation of household registration system. This paper uses a set of floating population survey data, population censuses data and statistical data to analyze the increase and influence of floating population on the urban population situations in beijing. It is found that beijing has experienced a rapid increase of floating population since the 1990s and that the increase of this group has become the key factor of the current population expansion in the city. Its distribution in the urban regions intensified and extended the suburbanization process of the capital. In addition, the population structures of sex, age, education and employment in beijing have changed to some extent due to the influx of floating population.

关键词： Floating population Household registration system (Hukou) Population expansion Suburbanization Population structure beijing

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

Three industries and wastewater and COD discharge of beijing

引用

Journal of Environmental Sciences 2000年第4期12卷 474-477页

作者： WANG Yan 1, WANG Hong rui 2. NING Da tong 2.(1. beijing Municipal Research Institute of Environmental Protection, beijing 10003., {2. 2. Institute of Environmental Sciences, beijing Normal University, beijing 100875, {2.) 北京市环境保护所北京 1 0 0 0 3 北京师范大学北京 1 0 0 875

With the swift development of economy, the water quality of beijing is becoming worse day by day and hampers the sustainable development obviously. In this paper, the current conditions of the municipal wastewater structure in the industrial sectors are analysed and discussed in terms of the indicators, such as direct wastewater\|discharge coefficient, complete wastewater\|discharge coefficient, direct discharge coefficient of COD and complete discharge coefficient of COD, by taking a year of 1990s as the base year. Some countermeasures are studied and the corresponding recommendations are put forward in order to improve the water environment in beijing. This provides a scientific ground for coordinating the relationship between the aquatic environment and economic growth in this city.

关键词： direct wastewater discharge coefficient (DWDC) complete wastewater discharge coefficient (CWDC) direct discharge coefficient of COD(DDC of COD) complete discharge coefficient of COD (CDC of COD)

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

Local and non-local sources of airborne particulate pollution at beijing——The ratio of Mg/Al as an element tracer for estimating the contributions of mineral aerosols from outside beijing

引用

Science china Chemistry 2005年第3期48卷 253-264页

作者： HAN Lihui1, ZHUANG Guoshun1,2.3. SUN Yele1 & WANG Zifa3.1. The Center for Atmospheric Environmental Study, Department of Chemistry, beijing Normal University, beijing 100875, {2. 2. Center for Atmospheric Chemistry Study, Department of Environmental Science & Engineering, Fudan University, Shanghai 2.043., {2. 3. LAPC/NZC, Institute of Atmospheric Physics, CAS, beijing 10002., {2. The Center for Atmospheric Environmental Study Department of Chemistry Beijing Normal University Beijing China Center for Atmospheric Chemistry Study Department of Environmental Science & Engineering Fudan University Shanghai China Institute of Atmospheric Physics CAS LAPC/NZC Beijing China

A new element tracer technique has firstly been established to estimate the contri-butions of mineral aerosols from both inside and outside beijing. The ratio of Mg/Al in aerosol is a feasible element tracer to distinguish between the sources of inside and outside beijing. Mineral aerosol, inorganic pollution aerosol mainly as sulfate and nitrate, and organic aerosol are the major components of airborne particulates in beijing, of which mineral aerosol accounted for 3.3.―67% of total suspended particles （TSP）, 10%―70% of fine particles （PM{3.5）, and as high as 74% and 90% of TSP and PM{3.5, respectively, in dust storm. The sources from outside beijing contributed 6{3. （3.%―86%） of the total mineral aerosols in TSP, 69% （5{3.―90%） in PM10, and 76% （59%―93.） in PM{3.5 in spring, and 69% （5{3.―83.）, 79% （5{3.―93.）, and 45% （7%―79%） in TSP, PM10, and PM{3.5, respectively, in winter, while only{3.% in summer and autumn. The sources from outside beijing contributed as high as 97% during dust storm and were the dominant source of airborne particulates in beijing. The contributions from outside Bei-jing in spring and winter are higher than those in summer, indicating clearly that it was related to the various meteorological factors.

关键词： mineral aerosol local sources non-local sources dust storm re-suspended dust element tracer technique.

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

Numerical simulation of topography effects on the “00.7” severe rainfall in beijing

引用

Progress in Natural Science:Materials International 2005年第9期15卷 818-826页

作者： ZHANG Chaolin1**, JI Chongping1, KUO Yinghwa2. FAN Shuiyong1, XUAN Chunyi3.and CHEN Min1(1. Institute of Urban Meteorology, china Meteorological Administration, beijing 100089, china 2. Mesoscale and Microscale Meteorology Division, National Center for Atmospheric Research, Boulder, CO 803.7-3.00, USA 3. beijing Meteorological Bureau, beijing 100089, china) Institute of Urban Meteorology China Meteorological Administration Beijing 100089 China Mesoscale and Microscale Meteorology Division National Center for Atmospheric Research Boulder CO 80307-3000 United States beijing Meteorological Bureau Beijing 100089 China

In an effort to study the severe rainfall event of 4—5th July 2.00 in beijing (with 2.h accumulated precipitation of 2.0 mm), we perform numerical simulations to investigate this event using the MM5v3.6 model. The model is initialized with the MM5/WRF 3.VAR analysis, which incorporates the ground-based GPS precipitable water vapor, automatic and conventional meteorological observations in its assimilation step. For 2. h accumulated precipitation forecast, the threat scores are 0.72. 0.76, 0.67 and 0.63. for thresholds of 1, 5, 10, and 2. mm, respectively. Holding other factors unchanged, sensitivity experiments were conducted with different topographic resolutions of 110, 50 and 3.7 km to investigate the topographic effects on precipitation over the beijing area. In these sensitivity experiments, we attempt to preserve the realistic orographic distribution in the model topography under the condition of keeping the dynamic-thermodynamic consistency of the initial model atmosphere to the extent possible. Results indicate that the unique topographic distribution and variations in the beijing area play an important role in determining the location, distribution and intensity of heavy precipitation.

关键词： topography heavy rainfall 3.VAR ground-based GPS numerical simulation.

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

Detection of the urban heat island in beijing using HJ-1B satellite imagery

引用

Science china Earth Sciences 2010年第S1期53卷 67-73页

作者： YANG Jun1,GONG Peng2.ZHOU JinXing3.HUANG HuaBing2.& WANG Lei2.1 Key Laboratory of Silviculture and Conservation,Ministry of Education,{3. Forestry University,{3. 100083.{2. 2.State Key Laboratory of Remote Sensing Science,jointly sponsored by the Institute of Remote Sensing Applications,chinese Academy of Sciences and {3. Normal University,beijing 100101,{2. 3.Institute of Desertification Studies,chinese Academy of Forestry,{3. 100091 {2. Key Laboratory of Silviculture and Conservation Ministry of Education Beijing Forestry University Beijing China State Key Laboratory of Remote Sensing Science jointly sponsored by the Institute of Remote Sensing Applications Chinese Academy of Sciences and Beijing Normal University Beijing China Institute of Desertification Studies Chinese Academy of Forestry Beijing China

Satellite images are used extensively in studying the urban heat island(UHI) *** evaluated the suitability of thermal infrared(TIR) data from the HJ-1B satellite for detecting UHI using a case study in *** modified algorithms for retrieving the land surface temperature(LST) from HJ-1B data were *** results were compared with LST images derived from a Landsat TM thermal band and the MODIS LST *** spatial pattern of UHI generated using HJ-1B data matched well with that produced using TM and MODIS *** the two algorithms,the mono-window algorithm performed better but further tests are *** more frequent coverage than TM and higher spatial resolution than MODIS,the HJ-1B TIR data present a unique opportunity to study thermal environments in cities in china and neighboring countries.

关键词： surface temperature NDVI mono-window algorithm single-channel algorithm

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

Discovery of immune related factors in Fenneropenaeus chinensis by annotation of ESTs

引用

Progress in Natural Science:Materials International 2004年第1期14卷 48-55页

作者： SHEN Yaoqing 1,2. , XIANG Jianhai 1*, WANG Bing 1,2. , LI Fuhua 1 and TONG Wei 3.1. Experimental Marine Biology Laboratory, Institute of Oceanology, chinese Academy of Sciences, Qingdao 2.6071,china 2. Graduate School of the chinese Academy of Sciences, beijing 10003., china 3. Genomics & Bioinformatics Institute, chinese Academy of Sciences, beijing 1013.0, china) chinese Acad Sci Inst Oceanol Expt Marine Biol Lab Qingdao 266071 Peoples R China chinese Acad Sci Grad Sch Beijing 100039 Peoples R China chinese Acad Sci Geonom & Bioinformat Inst Beijing 101300 Peoples R China

A total of 10446 expressed sequence tags (ESTs) are obtained by a large scale sequencing of a cDNA library from cephalothorax of adult Fenneropenaeus chinensis . An EST analysis platform was built up based on local computers and bioinformatic techniques were used to annotate these ESTs in order to promptly find possible functional genes, especially for immune related factors. About 4% of the ESTs show similarity to the coding sequences of such factors, including lectin, serine protease, serpin, lysozyme, etc. These ESTs provide a partial profile of the immune system in F. chinensis and useful information for further study on these genes.

关键词： Fenneropenaeus chinensis bioinformatics ESTs immune factors

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

Progress of Lyman-alpha-based beam emission spectroscopy(Ly BES)diagnostic on the HL-2. tokamak

引用

Plasma Science and Technology 2024年第3期26卷 118-125页

作者：周艺轩余羿许敏柯锐聂林徐皓赵光义刘灏袁子豪肖晨雨李继全肖池阶 the HL-2. Team Southwestern Institute of Physics Chengdu 610041People's Republic of China Sino-French Institute of Nuclear Engineering and Technology Sun Yat-sen UniversityZhuhai 519082People's Republic of China State Key Laboratory of Nuclear Physics and Technology School of PhysicsPeking UniversityBeijing 100871People's Republic of China

An edge Lyman-alpha-based beam emission spectroscopy(LyBES)diagnostic,using a heating NBI(neutral beam injection)system,is currently under development on the HL-2. *** 2.-channel edge LyBES,which is intended to measure the density fluctuation in plasma edge(from R=1960 mm to R=2.2. mm)with an improved spatial resolution of 3.3.mm,is a complement to the existing conventional beam emission spectroscopy(BES)*** this article,we introduce the progress of LyBES diagnostic,including the collection optics,the monochromator,and the detector *** reflectance of the collection mirrors is measured to be~82.at 12. nm,and the aberration geometrical radius of the collection optics is tested to be~150μm in the aimed *** linear dispersion of the LyBES monochromator is designed to be~0.09 nm mm^(-1).The bandwidth of the detector system with the 5×10^(7)V A^(-1)preamplifier gain is measured to be~2.0 kHz,and the peak-to-peak noise of the detector system is tested to be~16 *** finalized design,components development and testing of the LyBES diagnostic have been completed at present,and an overall performance of the LyBES diagnostic is to be confirmed in the next HL-2. campaign.

关键词： density fluctuation Ly BES BES vacuum ultraviolet

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

Debris Flow Hazard Assessment Based on Support Vector Machine

引用

Wuhan University Journal of Natural Sciences 2006年第4期11卷 897-900页

作者： YUAN Lifeng 1, 2., ZHANG Youshui 3. 1. Institute of Mountain Hazards and Environment, chinese Academy of Sciences, Chengdu 610041, Sichuan, china 2. Graduate University of chinese Academy of Sciences, beijing 100049, china 3. Institute of Geographical Sciences and Natural Resources Research, chinese Academy of Sciences, beijing 100101, china Institute of Mountain Hazards and Environment Chinese Academy of Sciences Chengdu Sichuan China Graduate University of chinese Academy of Sciences Beijing China Institute of Geographical Sciences and Natural Resources Research Chinese Academy of Sciences Beijing China

Seven factors, including the maximum volume of once flow , occurrence frequency of debris flow , watershed area , main channel length , watershed relative height difference , valley incision density and the length ratio of sediment supplement are chosen as evaluation factors of debris flow hazard degree. Using support vector machine （SVM） theory, we selected 2.9 basic data of 3. debris flow channels in Yunnan Province as learning samples in this study. We create a debris flow hazard assessment model based on SVM. The model was validated though instance applications and showed encouraging results.

关键词： debris flow hazard assessment support vector machine (SVM)

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

Paleotemperature changes over the past 3.00 years in eastern beijing, china: A reconstraction based on Mg/Sr records in a stalagmite

引用

chinese Science Bulletin 2003年第4期48卷 395-400页

作者： MA Zhibang1, LI Hongchun2. XIA Ming1, KU Tehlung2. PENG Zicheng3. CHEN Yushu4 & ZHANG Zhaofeng3.1. Institute of Geology and Geophysics, chinese Academy of Sciences, {3. 10002., {2. 2. Department of Earth Sciences, University of Southern California, Los Angeles, CA90089-0740, USA 3. Department of Earth and Space Science, University of Science and Technology of {2., Hefei 2.002., {2. 4. {3. Foshan Tourist Service Centre, {3. 1012.1, {2. Institute of Geology and Geophysics Chinese Academy of Sciences Beijing 100029 China Department of Earth Sciences University of Southern California Los Angeles CA 90089-0740 United States Department of Earth and Space Science University of Science and Technology of China Hefei 230026 China beijing Foshan Tourist Service Centre Beijing 101201 China

The Mg/Sr ratio in a stalagmite, which is di-rectly proportional to DMg/Ca, the solid-liquid distribution coefficient of Mg, is proposed as a geochemical thermometer to estimate paleotemperature changes. The paleotempera-ture change in eastern beijing over the past 3.00 years has been reconstructed by using this thermometer in the stalag-mite ZFFS-1 from Jingdong Cave. The records can be di-vided into two periods: 3.00—2.00 aBP, cool and wet, the air temperature averaging 9.8℃; and 2.00 aBP—present, hot and dry, the air temperature being 1℃ higher than the mean value (11.7℃) of the past 3.00 years. During 500—2.0 aBP, the air temperature was about 1.2. lower than that of the present, corresponding to the Little Ice Age in Europe. Like d 18O and d 13., Mg/Sr (or DMg/Ca) reflects an obviously warming trend of the past 2.0 years. These results are sup-ported by historic records.

关键词：北京京东溶洞石笋 Mg/Sr记录古气温测年 3.00年

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：