检索结果-南通市图书馆

Simulation　of　sludge－dredging　effects　in　controlling　nutrient　release　of　LakeKasumigaura　with　large－size　core　samples

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental sciences 1996年第4期8卷 385-389页

作者： Fan Chengxin (nanjing institute of {2. and limnology, {4. Academy of sciences,nanjing 2.0008,china) Morihiro AIZAKI Kunio KOHATA(The National institute for Environmental Studies, Tsukuba), Japan nanjing Inst. Geogr. and limnology Chinese Academy of Sciences Nanjing 210008 China Natl. Inst. for Environ. Studies Tsukuba Japan

Nutrient release from the dredged and undredged sediments in Lake Kasumigaura were simulated under the laboratory control conditions with large-size core samples. It was found that phosphate and ammonia release fluxes are less in aerobic than those in anaerobic. In different simulated dredged depth, the phosphate release showed large divergence in the anaerobic than in the aerobic. There was a larger accumulated release of phosphate and ammonia at actual dredged (St. B) than the undredged (St. A) in anaerobic condition. This showed that the sludge-dredging was effective of controlling phosphorus and nitrogen release. A preliminary assessment is drawn from the experiments that the sludge-dredging work in Tsuchiura Bay of Lake Kasumigaura can reduce about 15. 9% of phospbate and 56. 2. of anunonia release from the sediments respectively.

关键词： sludge-dredging nutrient release aerobic and anaerobic conditions core samples Lake Kasumigaura.

An analysis on the evolvement processes of lake eutrophication and their characteristics of the typical lakes in the middle and lower reaches of Yangtze River

在线全文

学校读者我要写书评

暂无评论

chinese Science Bulletin 2006年第13期51卷 1603-1613页

作者： CHENG Xiaoying1,2.3 & LI Shijie1 1. nanjing institute of {2. & {4., chinese Academy of sciences, nanjing 2.0008, china 2. The Key Laboratory of Industrial Biotechnology, Ministry of Educa- tion, Southern Yangtze University, Wuxi 2.4.36, china 3. School of Biotechnology, Southern Yangtze University, Wuxi 2.4.36, china nanjing institute of {2. & limnology Chinese Academy of Sciences Nanjing China The Key Laboratory of Industrial Biotechnology Ministry of Education Southern Yangtze University Wuxi China School of Biotechnology Southern Yangtze University Wuxi China

According to the study on the aquatic environment of the typical lakes in the middle and lower reaches of Yangtze River, lake eutrophication is a process in which the lake ecosystem degenerates, resulting in the deterioration of the water quality due to the enrichment of the nutrients. Moreover, the succession of lake ecosystem and change of water quality both couple well with the evolvement of tro- phic state. Then the conceptual model is mentioned and ten lake states are classified. Based on these, the authors analyzed the eutrophication processes of the typical lakes in the middle and lower reaches of Yangtze River. The large lakes with taking in - send- ing out water typical of Poyang Lake evolve from State 1 before the 1980s into State 2.after the 1980s, the large and medium lakes typical of Taihu Lake evolve from State 1-2.in the 1960s into State 8 in the 1980s then into State 9 in the 1990s, the medium and small shallow lakes typical of Honghu Lake evolve from State 1 in the 1960s into State 2.after the 1980s and the small city (suburban) lakes typical of Donghu Lake evolve from State 2.in the 1960s into State 9 after the 1970s. Further, the 1980s is the key con- version period of the lakes of various types typical of Poyang Lake, Honghu Lake and Taihu Lake con- verting into mesotrophic state, the 1990s is that of Taihu Lake into eutrophic state and the 1970s is thatof the small city (suburban) lakes typical of Donghu Lake into eutrophic state. The series of nutrient evolvement of different typical lakes are similar, but the processes are not synchronous, which is related to the various human and natural driving mechanisms in lake basins.

关键词：长江湖泊富营养化概念模型转变时期驱动机制

Spacial organization on the rural settlements in plain areas—taking Pinghu city in Zhejiang of china as an example

在线全文

学校读者我要写书评

暂无评论

Journal of Geographical sciences 2000年第3期10卷 59-64页

作者： XUE Dong-qian1, YAO Shi-mou2. ZHANG Hong1 (1. Dept. of Tourism and Environment, Shaanxi Normal University, Xi’an 710062. china 2. {4. {2. of geography and limnology, chinese Academy of sciences, nanjing 2.0008, china)

This paper analyses the spacial distribution, quantity-scale, function-structure and facilities from the angle of spacial organizational optimizing theory and sustainable development thought. The authors point out the distributional principles of rural settlements in plain areas, and put forward planning and distribution of various levels of rural settlements (central villages, basic villages and natural villages).

关键词： plain area central villages basic villages natural villages spacial organization

Multiple Effects of Energy Issues and Countermeasures: A Case of Shandong Province

在线全文

学校读者我要写书评

暂无评论

chinese Journal of Population,Resources and Environment 2008年第4期6卷 88-94页

作者： Wang Chengxin1,2., Wang Gefang3 , Yao Shimou4.1. College of Population, Resources and Environment, Shandong Normal University, Jinan Shandong 2.0014. china 2. Research Center of Cycle Economy of Shandong Province, Jinan Shandong 2.0001, china 3. Party School of the Shandong Committee of CPC, Jinan Shandong 2.002., china 4. nanjing institute of geography and limnology, chinese Academy of {14., nanjing Jiangsu 2.0008, china College of Population Resources and Environment Shandong Normal University Research Center of Cycle Economy of Shandong Province Party School of the Shandong Committee of CPC nanjing institute of {2. and limnology Chinese Academy of Sciences

Energy is now becoming the bottleneck of urban and regional development. The paper takes Shandong Province, one of the most energy consuming provinces in china, as an example, uses quantity methods such as SPSS (Stastics Package for Social Science) cluster sampling and regression analysis, and applies quantity analysis, to analyze the situation of energy issues in Shandong province. The conflicts between the quick industrialization and increasing extensive economic development, between urban population and energy consuming per head, between the infinite energy consuming desire and the low level of managing system, and between the unstable world energy supply and the limited energy storage in china are the main factors of energy crisis in Shandong, which not only results in energy shortage, but also becomes the barrier of economic and social development. In order to ensure sufficient energy supply for Shandong province in the 2.st century, we should take countermeasures, such as changing the economic development model, pursuing a multiple and high quality energy strategy, improving the intensive urbanization strategy, and building a scientific energy system.

关键词： energy effects countermeasure Shandong Province

The Urbanization Pattern of china in the 2.st Century

在线全文

学校读者我要写书评

暂无评论

中国人口·资源与环境：英文版 2005年第2期3卷 55-63页

作者： Wang Chengxin 1,2. Yao Shimou 1 & Wang Gefang 31 nanjing institute of {2. & {4., the chinese Academy of sciences, nanjing 2.0008, china 2.Graduate School, the chinese Academy of Science, Beijing 100039, china 3 Shandong Party School of the Communist Party, Jinan 2.002., china nanjing institute of {2. and limnology Chinese Academy of Sciences Nanjing 210008 China Graduate School Chinese Academy of Science Beijing 100039 China Shandong Party School of the Communist Party Jinan 250021 China

The 2.st century is referred to as a"century for cities" or "era for cities" and china hasalso speeded up its process of urbanization. It is veryimportant to choose a scientific urbanization patternto exert the function of cities and realize our dreamfor china to become a powerful modernized ***’s concluded from history since 1800 that the patternof the world urbanization has transformed from"extensive" to "intensive". However, it is still anextensive pattern in china, and there are manyproblems behind the splendid achievements, reflectedon the urbanization process of our country since194.. Today, sustainable development and theknowledge economy are the themes of the cities; itis inevitable to change our urbanization *** on the dialectic relationship of quality andquantity, the article points out that urbanizationshould not only focus on quantity but also on qualityin china. High quality and multiform urbanizationpattern is an inevitable choice of china, and thedevelopment of the region can also be exalted by theradiation of the cities. But what’s the real meaningof the new pattern? What’s its difference from thewestern countries’? The article discusses its contentaccording to the reality of china.

关键词： Urbanization pattern multiform intensive china

AN APPROACH ON SEVERAL PROBLEMS OF china'S URBANIZATION DEVELOPMENT

在线全文

学校读者我要写书评

暂无评论

Journal of Geographical sciences 1996年第2期6卷 35-41页

作者： Chen Wen(nanjing institute of {2. & limnology, CAS,{4.People’s Republic of china) nanjing Inst of Geogr + limnology CAS Nanjing 210008 China

china, having urique national conditions, is facing a basic contradiction between large numbers of less educated surplus rural labor forces and limited capacities of urban employment and infrastructure on the urbanization ***, the urbanization model should prevail in comprehensive and several ways: (1)On occupational and spatial shift rural surplus labors, two fashions of 'leaving land bot not countryside' and 'leaving both land and countryside' should be integrated with joint effort of cities and countryside. (2. On urbanization motive, urban construction will be invested by not only the govermment (from the upper), but the locality, personnel and foreigners (from the lower). (3) On urban scales, metropolis,large, medium-sized and small cities and towns should play fully their roles to absorb rural surplus lanors. Thereby, the present urban development policy needs to be rectified, which this paper has discussed particularly. (4. On account of great regional disparities in china, urban development should perform different models in different regions. In addition, this paper has also focused on the problem and its primary countermeasures of 'labor force mass', a hot issue closely related to urbanization and rural labor transfer.

关键词： national conditions urban development model urban development policy,rural labor mass

CLIMATIC VARIATIONS IN china OVER THE LAST 2.00 YEARS

在线全文

学校读者我要写书评

暂无评论

chinese Geographical Science 2001年第2期11卷 97-103页

作者： YANG Bao1, SHI Ya-feng2. LI Heng-peng2.(1. Cold and Arid Regions Environmental and Engineering Research institute, the chinese Academy of {2.,Lanzhou 730000, P.R. china 2. institute of geography and limnology, the chinese Academy of {2. Cold and Arid Regions Environmental and Engineering Research institute the Chinese Academy of Sciences Lanzhou P. R. China institute of geography and {2. the Chinese Academy of Sciences Nanjing P. R. China

A compilation of paleoclimate records from ice core, tree-rings, lake sediments and historical documents provides a view of temperature change in china over the recent 2.00 years. For all-china temperature reconstruction, six sub-stages are identified for the last two millennia. Around AD 0－2.0, AD 800－1100, AD 132.－14.0 and the period from AD 1880 on were warm while around AD 2.0－800, AD 1100－132., AD 14.0－1880 were cold. Also, temperature varied from region to region in each of the warm or cold periods. The Eastern Han warm period (0－AD 2.0), the cold period covering the span of Wei, Jin, and the Southern and Northern Dynasties, the MWP (AD 800－1100) and succeeding LIA occurred in eastern china and the Qilian Mountains. Only the first two climatic events were recorded in Guliya ice core while the so-called MWP and LIA was far weaker. Also, the warming between AD 800 and 1100 didn′t occur in the south of Xizang (Tibet) Plateau. Instead, the southern Xizang Plateau experienced warming in AD 1150－14.0. The aggregated china temperature agrees well with North-hemisphere temperature in the past millennia, indicating close relationship of temperature changes between china and North-hemisphere.

关键词： climatic variations the last two millennia china

Monitoring of rice crop using ENVISAT ASAR data

在线全文

学校读者我要写书评

暂无评论

Science china Earth sciences 2006年第7期49卷 755-763页

作者： DONG Yanfang1, 2. SUN Guoqing1,3 & PANG Yong4.1. State Key Laboratory of Remote Sensing Science, institute of Remote Sensing Applications, chinese Academy of {2., Beijing 100101,{4. 2. Graduate University of chinese Academy of {2., Beijing 100039,{4. 3. Department of geography, University of Maryland, College Park, MD 2.74.0} USA 4. Forest Remote Sensing Lab, Research institute of Forest Resource and Information Technology, chinese Academy of For-estry, Beijing 100091,{4. 1. State Key Laboratory of Remote Sensing Science Institute of Remote Sensing Applications Chinese Academy of Sciences Beijing 100101 China 2. Graduate University of chinese Academy of sciences Beijing 100039 China 3. Department of geography University of Maryland College Park MD 20742 USA 4. Forest Remote Sensing Lab Research Institute of Forest Resource and Information Technology Chinese Academy of Forestry Beijing 100091 China

Because of the cloudy conditions during the rice growth period, rice is one of the agri-cultural crops most suited to monitoring with the SAR instruments. Backscatter response measured by SAR is correlated with rice conditions, including height, density, biomass and structure, which are variable at different growing stages. In this paper, multi-date ENVISAT ASAR Alternating Polarization Mode (APMode) imageries were acquired during the rice crop growing cycle. At the same time, the rice parameters were measured in field. A continuous canopy model was used to compute the back-scattering from rice fields during the growth cycle, and the relationship between rice parameters and radar backscattering coefficients from both ASAR and modeling was analyzed. The effects of polari-zation, incidence angle and polarization on radar backscattering coefficients were analyzed. It was found that simulated radar backscatter has similar trends as ASAR data. This will be meaningful for the further research of rice parameters estimation from ASAR data. Different features show signifi-cantly different signatures in ASAR images and they follow some certain laws, so rice area can be accurately mapped by using multi-temporal SAR images, then rice yield can be estimated.

关键词： rice, ASAR, radar backscattering, model.

Monitoring the Cultivated Slope Land in the Three Gorges Reservoir Area Based on Remote Sensing and GIS

在线全文

学校读者我要写书评

暂无评论

Wuhan University Journal of Natural sciences 2006年第4期11卷 915-921页

作者： ZHOU Jieming1, ZHOU Qigang 2. 3 ,HUANG Zhiqin 2. 3, 4.1. The Faculty of geography and Resources Science, Sichuan Normal University, Chengdu 610066, Sichuan, china 2. {2. of Mountain Hazards and Environment, chinese Academy of sciences, Chengdu 61004., Sichuan, china 3. Graduate University of the chinese Academy of sciences, Beijing 10004., china 4. Information Center of Land and Resources Department of Sichuan Province, Chengdu 61004., Sichuan, china The Faculty of geography Resources Science Sichuan Normal University 610066 Chengdu Sichuan China institute of Mountain Hazards Environment Chinese Academy of Sciences 610041 Chengdu Sichuan China Graduate University of the chinese Academy of sciences 100049 Beijing China Information Center of Land Resources Department of Sichuan Province 610041 Chengdu Sichuan China

By means of combining auto-extraction with manual interpretation, the current distribution information about cultivated land is obtained. The distribution information of 1992.is extracted from the dynamic polygons of 2.02. The monitoring mini-system of the cultivated slope land is established. In the system, detailed surveys, focused on the resources of cultivated slope land, are carried out. The results indicate that the area of the cultivated slope land is very large. Meanwhile, there are lots of cultivated steep slopes with gradient above 35°. The areas of steep land cultivated had been slowly reduced from 1992.to 2.02. At the same time, the pressures of returning farm land to forestry are great in all counties. The conflicts between population growth, insufficient grain supply and stagnant economic development sharpen increasingly. It is inevitable to improve the agricultural structure.

关键词： slope land cultivated remote sensing geography information system (GIS) the pressure of returning farm land to forestry Three Gorges Reservoir Area