检索结果-南通市图书馆

Potential land for plantation of Jatropha curcas as feedstocks for biodiesel in china

Science china Earth Sciences 2010年第1期53卷 120-127页

作者： WU WeiGuang 1,2,3,HUANG JiKun 1,3 & DENG XiangZheng 1,3 1 Institute of Geographic Sciences and Natural Resources Research,Chinese Academy of Sciences,Beijing 100101,china 2.department of economics and management,zhejiang forestry university,linan 311300,china 3 Center for Chinese Agricultural Policy,Chinese Academy of Sciences,Beijing 100101,china 1. Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China2. Department of Economics and Management Zhejiang Forestry University Linan 311300 China3. Center for Chinese Agricultural Policy Chinese Academy of Sciences Beijing 100101 China

As a renewable energy,biofuel has attracted great attention in china and the rest of *** with the national food security,china recently has shifted its biofuel development priority from grain-based to non-grain-based biofuels,including forest-based biodiesel,since *** curcas is one of major biodiesel ***,there is rising debate on availability of land for expanding Jatropha curcas *** overall goal of this paper is to evaluate potential land for Jatropha curcas used as feedstock for biodiesel in *** on remote sensing data on land use,data on meteorological,soil and land slope,and suitable environment for Jatropha curcas plantation,this study uses Agro Ecological Zone method and considers social-economic constraints to evaluate potential suitable land for Jatropha curcas plantation in china's major Jatropha curcas production region,Southwest *** results show that while there are some potential lands to expand Jatropha curcas areas,amount of these lands will hardly meet the government's target for Jatropha curcas-based biodiesels development in the *** may need to reconsider its long-term targets on the development of Jatropha curcas-based biodiesels.

关键词： biodiesel Jatropha curcas potential land suitability evaluation Southwest china

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

Climate instability during the last glaciation recorded in the Yuanbu loess section

引用

Progress in Natural Science:Materials International 2009年第4期19卷 453-459页

作者： Yimeng Chen department of economics & management, Huizhou university, Huizhou 516007, china [a]department of economics & management Huizhou University Huizhou 516007 China

Abrupt events within the Linxia Yuanbu loess section in the western Loess Plateau in china were investigated. The climatic proxy index of the content of mean grain-size and >4 lm grain-size fraction of the section was used as a climatic indicator, and a moving average method was applied in the statistical analysis to extract the abrupt events recorded in the section. It was found that the loess of the last glaciation recorded not only the abrupt events teleconnected with the high-latitude North Atlantic and Greenland regions but also as many as 15 abrupt events in addition to the Heinrich (H) and Younger Dryas (YD) events. This indicates that abrupt climate changes were typical of the climate changes occurring in the Loess Plateau during the last glaciation. The widely recognized mechanisms of the abrupt climate changes, including the heat transfer theory of the North Atlantic Ocean, the atmospheric circulation theory, and the theory of the interac- tion between low-latitude ocean and the atmosphere remains to be discussed. Perhaps this problem could be resolved by revealing the rela- tion between the evolution of the features of the East Asian monsoon climate and the climate in the surrounding areas. Through a detailed study of the features of the Heinrich and YD events, criteria on which the abrupt events recorded in the loess could be distinguished were tentatively defined. The events were associated with a large grain size, high carbonate content, high lightness, low susceptibility, low redness and low yellowness. In addition, the variation amplitude of the adjacent peak and valley on the curve of the content of the mean grain-size and >40 lm grain-size fraction was larger than 3.4 lm and the content of >40 lm grain-size fraction was larger than 2.0 lm. Lastly, the length of the variation time was less than 500 years. If all these criteria were met, the event was viewed as an abrupt event.

关键词： Climate instability Moving average Abrupt event Last glaciation Loess section

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

Social forestry and Women in china

引用

北京林业大学学报 1992年第S2期14卷 142-147页

作者： Xie Jingxiang Wen YaliCollege of economics and management, Beijing forestry university

Although there is no uniform concept about social forestry in the world,its aim of servicing mankind is commonly considered,and the importance ofwomen’s participation is recognized. Women in china,as an important part of the labor force involved in thedevelopment of social forestry,can be divided into three categories according tothe type of women’s participation. Firstly women(as well as men)have the obligation to participate in

关键词： forestry participation mankind obligation participate women themselves think arrange daughter

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

Study on Building an Econometric Model of Canada's Newsprint Exports to the United States of America

引用

北京林业大学学报 1992年第S2期14卷 130-141页

作者： Liu JunchangCollege of economics and management, Beijing forestry universityG. HazenbergSchool of forestry, Lakehead university ,Canada

For predictive purposes and for understanding the relationship between the US market and Canadian newsprint producers an econometric model was built. In this study, a simultaneous-equation model was developed, which consisted of four equations, one each for the supply, export, consumption and price of newsprint. The period of 1955-1986 was covered by this model. The data for the years 1985 and 1986 were reserved to test the predictive power of the model. In fitting the four equations for the period of 1955 -1984, the coefficients of determination, the R -square values, between observed and predicted values were higher than 99 per cent. The test results of the forecasting power showed that there was no statistically significant difference between predicted and observed values at the 5 per cent level of significance. Sources of forecasting error are expressed as three partial inequality coefficients associated with bias, variance and covariance of predicted and observed values. The error could not be

关键词： simultaneous-equation model newsprint supply export consumption price

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 asymptotic behavior of the survival probability of the equilibrium renewal model with heavy tails

引用

Science china Mathematics 2005年第3期48卷 300-306页

作者： JIANG Tao & CHEN Yiqing School of Finance. Nanjing university of Finance and economics, Nanjing 210003, china School of economics and management, Guangdong university of Technology, Guangzhou 510090, china 1. School of Finance Nanjing University of Finance and Economics 210003 Nanjing China 2. School of economics and management Guangdong University of Technology 510090 Guangzhou China

Recently, Tang established a local asymptotic relation for the ruin probability in the Cramer-Lundberg risk model. In this short note we extend the corresponding result to the equilibrium renewal risk model.

关键词： geometric sums, heavy-tailed distribution, ladder height, the equilibrium renewal model, the ruin probability.

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

Reengineering Model of Supply Chain of Tea Industry in Yunnan

引用

厦门大学学报（自然科学版） 2002年第S1期41卷 230-231页

作者： LI Yan-feng 1, JIANG Fa-kui 2 (1. management School, Huazhong university of Science and Technology, Wuhan 430074, china 2. department of Business Administration, Yunnan university of Finance and economics, Kunming 650221, china)

Yunnan university of finance and Trade recording to t he statistics of chain’s output of tea, Yunnan province has entered the ranks of the larger ones of the production in china. Yunnan’s tea industry has the natur al resources and the economic effects envied, on the orther hand, Yunnan’s tea m arket has gradually become less and the economic effects have been poor. Through our comprehensive investigation and study, we consider that because the supply chain has seriously been disjointed among production, supply and sale of tea ind ustry in Yunnan, the supply chain of Yunnan’s tea industry need to be reorganize d for the promoting the development of Yunnan’s tea industry. The essence of reengineering of Yunnan’s tea industrial supply chain is to set u p the model of the trailed operation,to strengthen the strategic partnership man agement between the supply chain, to optimize the design of the supply chain and build up and improve the working mechanism for management of the tea industrial supply chain. The structure of Yunnan’s model of tea industrial supply chain: the model of com mercial flow; the model of logistics flow; the model of information flow and the model of cash flow. The solutions and policies for the reorganization of Yunnan’s tea industrial sup ply chain: planning, logistics and distribution and sales. Set up the supporting system of information technology. Build up the control system of production and *** the working mechanism of Yunnan’s tea industrial supply chain. Implement the engineering of exporting Yunnan’s tea into the markets of other p rovinces and foreign markets. Have many the channels that raise the funds of dev elopment for Yunnan’s tea industry.

关键词： Yunnan tea industry reengineering supply chain building model

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

股改前后上市公司股权结构与公司绩效关系分析

引用

上海交通大学学报 2009年第4期43卷 602-605,611页

作者：黄静屠梅曾上海交通大学安泰经济与管理学院上海200052 江西财经大学会计学院南昌330013

以2005年底完成股权分置改革的上市公司为样本,采用纵向比较思路以及多指标绩效评价的数据包络分析(DEA)方法,以新的视角,刻画和分析了我国股权分置改革前后上市公司的股权结构与公司绩效关系的时序演变.结果表明,股权分置改革后,上市... 详细信息

以2005年底完成股权分置改革的上市公司为样本,采用纵向比较思路以及多指标绩效评价的数据包络分析(DEA)方法,以新的视角,刻画和分析了我国股权分置改革前后上市公司的股权结构与公司绩效关系的时序演变.结果表明,股权分置改革后,上市公司的平均绩效逐渐增长,国有股比例高与比例低的2组公司平均绩效间的差异逐渐缩小,且股权分散公司的平均绩效提升速度大于股权集中的公司.

关键词：股权分置改革股权结构公司绩效数据包络分析

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

Test of magnetic susceptibility and grain-size age models of loess

引用

Progress in Natural Science:Materials International 2007年第11期17卷 1312-1317页

作者： Chen Yimeng1,2,3, Feng Zhaodong4 and Gong Huili1,2(1. MOE and Key Laboratory of Resources Environment and GIS of Beijing, Beijing 100037, china 2. Key Laboratory of 3D information Acquisition and Application, The Capital Normal university, Beijing 100037, china 3. department of economics & management of Huizhou university, Huizhou 516007, china 4. Key Laboratory of Western china’s Environmental Systems, Ministry of Education, Lanzhou university, Lanzhou 730000, china) MOE and Key Laboratory of Resources Environment and GIS of Beijing Beijing 100037 China Key Laboratory of 3D information Acquisition and Application The Capital Normal University Beijing 100037 China department of economics & management of Huizhou university Huizhou 516007 China Key Laboratory of Western china’s Environmental Systems Ministry of Education Lanzhou University Lanzhou 730000 China

Ages of the stratigraphic boundary MIS1/2 and MIS3/4 of the Yuanbu loess section in Linxia are used as the basis of the nodal control age. The age of MIS1/2 and MIS3/4 are obtained from the latest international research result—the climatic events recorded in the stalagmite in the Hulu Cave in Nanjing, that MIS1/2 is 11.5 kaB.P. and MIS3/4 is 59.8 kaB.P.. The ages of the two climatic events contain three nodal age control models (Model 1: 0 kaB.P.—59.8 kaB.P.; Model 2: 0 kaB.P.—11.5 kaB.P. and 11.5 kaB.P.—59.8 kaB.P.; Model 3: 11.5 kaB.P.—59.8 kaB.P.), which are used as the nodal control age separately. The deposition times of various stratigraphic horizons are calculated by using the magnetic susceptibility age model and grain-size age model, and then compared with each other. In addition, the AMS14C age, OSL age and the ages of YD and H events are compared with the ages of the corresponding horizons calculated by the three models of nodal control ages. From the analyses of lithologic characters and climatic stages it has been found that both the magnetic susceptibility age model and the grain-size age model have some defects. Because the accurate control ages are selected as the nodal points of the glacial period or interglacial period, the stratigraphic deposition times determined by the high resolution of magnetic susceptibility age model and grain-size age model approximate to the actual ages. As for the relative accuracy of the two age models, the magnetic susceptibility age model is more accurate than the grain-size age model.

关键词： loess nodal control age magnetic susceptibility age model grain-size age model test

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

Mapping forest fire risk zones with spatial data and principal component analysis

引用

Science china(Technological Sciences) 2006年第z1期49卷 140-149页

作者： XU Dong, Guofan Shao, DAI Limin, HAO Zhanqing, TANG Lei & WANG Hui Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, china Graduate university of Chinese Academy of Sciences, Beijing 100039, china department of forestry and Natural Resources, Purdue university, West Lafayette, IN 47907, USA department of management, Shenyang Institute of Aeronautical Engineering, Shenyang 110034, china department of City Development, Jinan university, Jinan 250002, china 1. Institute of Applied Ecology Chinese Academy of Sciences Shenyang 110016 China2. Graduate University of Chinese Academy of Sciences Beijing 100039 China3. Department of Forestry and Natural Resources Purdue University West Lafayette IN 47907 USA4. Department of Management Shenyang Institute of Aeronautical Engineering Shenyang 110034 China5. Department of City Development Jinan University Jinan 250002 China

By integrating forest inventory data with remotely sensed data, new data layers for factors that affect forest fire potentials were generated for Baihe forestry Bureau in Jilin Province of china. The principle component analysis was used to sort out the relationships between forest fire potentials and environmental factors. The classifications of these factors were performed with GIS, generating three maps: a fuel-based fire risk map, a topography-based fire risk map, and an anthropogenic-factor fire risk map. These three maps were then synthesized to generate the final fire risk map. The linear regression method was used to analyze the relationship between an area-weighted value of forest fire risks and the frequency of historical forest fires at each forest farm. The results showed that the most important factor contributing to forest fire ignition was topography, followed by anthropogenic factors.

关键词： wildfire risk, regression analysis, geographic information system, remote sensing, Baihe forestry Bureau.

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 Study on the Structural Optimization and Dynamic Prediction of Forest Resources in Nanping Prefecture of Fujian Province

引用

北京林业大学学报 1993年第S3期 70-82页

作者： Zhao Daosheng College of economics and management,Beijing forestry university Yan Shuai Editorial Staff of J.of Beijing For.Univ.

Based on the analyses of the current state of forest resources, existing problems concerningthe structure of forest resources are pointed out. To help determining the future developmental direction offorest resources, a model of the structure was developed by the application of linear programming. The resultsof the optimal structure of forest resources can be obtained from this model. To forecast the futurecondition of the forest stand , a dynamic model was developed by using a method of system dynamics. Themodel can be utilized to estimate the future area and volume of the forest stand , the area of forest land ,the area and volume of commercial forest , and the quality of the stand.

关键词： structural optimization dynamic prediction optimal model dynamic model model 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

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：