提出了1 000 k V交流输电系统提高输电能力,降低成本的参数优化模型,分析了1 000 k V与±800 k V输电系统技术经济性,以中国示范工程数据为基础估算了它们的建设成本,提出了改进的年运行成本法和稳定性成本法并用于1 000 k V与±...提出了1 000 k V交流输电系统提高输电能力,降低成本的参数优化模型,分析了1 000 k V与±800 k V输电系统技术经济性,以中国示范工程数据为基础估算了它们的建设成本,提出了改进的年运行成本法和稳定性成本法并用于1 000 k V与±800 k V输电系统技术经济评估。1 000 k V和±800 k V输电系统,输电距离1 500±2 000 km,按静态(热)稳定输送功率,单位输电建设成本处于相同水平;1 000 k V输电系统的年运行成本明显低于±800 k V输电系统。1 000 k V输电系统暂态稳定输送功率的单位输电建设成本也明显低于±800 k V输电系统。1000 k V输电系统经济性优于±800 k V输电系统。展开更多
Soil classification is the foundation for exchange and extension of research findings in soil science and for modern management of soil resources. This study explained database and research methodology to create a cro...Soil classification is the foundation for exchange and extension of research findings in soil science and for modern management of soil resources. This study explained database and research methodology to create a cross-reference system for translating the Genetic Soil Classification of China (GSCC) into the Chinese Soil Taxonomy (CST). With the help of the CST keys, each of the 2 540 soil species in GSCC has been interpreted to its corresponding soil order, suborder, great group, and sub-group in CST. According to the methodology adopted, the assigned soil species have been linked one another to their corresponding polygons in the 1:1000000 digital soil map of China. Referencibility of each soil species between the GSCC and CST systems was determined statistically on the basis of distribution area of each soil species at a high taxon level of the two systems. The soils were then sorted according to their maximum referencibility and classified into three categories for discussion. There were 19 soil great groups in GSCC with maximum referencibility > 90% and 22 great groups between 60%-90%. These soil great groups could serve as cross-reference benchmarks. There were 19 great groups in GSCC with maximum referencibility < 60%, which could be used as cross-reference benchmarks until new and better results were available. For these soils, if the translation was made at a lower soil taxon level or on a regional basis, it would improve their referencibility enabling them to serve as new cross-reference benchmarks.展开更多
Geomorphologic maps are one of the most fundamental materials of the natural environment. They have been widely used in scientific research,resource exploration and extraction,education and military affairs etc. An ed...Geomorphologic maps are one of the most fundamental materials of the natural environment. They have been widely used in scientific research,resource exploration and extraction,education and military affairs etc. An editorial committee was established in 2001 to collect materials for researching and compiling a set of new 1：1,000,000 geomorphologic atlas of China. A digital geomorphologic database was created with visual interpretation from Landsat TM/ETM imageries and SRTM-DEM etc. The atlas compiled from the database was finished. The main characteristics of the atlas are as follows：Firstly,Landsat TM/ETM imageries,published geomorphologic maps or sketches,geographical base maps,digital geological maps,and other thematic maps were collected,which were uniformly geometrically rectified,clipped into uniform sheets,and stored in the foundation database. Secondly,based on the legends of 15 sheets 1：1,000,000 maps published in the 1980s,a geomorphologic classification system was built by combining morphology and genesis types. The system comprised seven hierarchical layers：basic morphology,genesis,sub-genesis,morphology,micro-morphology,slope and aspect,material composition and lithology. These layers were stored in the database during visual image interpretation. About 2000 kinds of morpho-genesis and 300 kinds of morpho-structure were interpreted. Thirdly,the legend system was built,which included color,symbol bases and note bases etc.,compilation standards and procedures were developed,74 sheets of 1：1,000,000 covering all land and sea territories of China were compiled,the 1：1,000,000 geomorphologic atlas of the People＇s Republic of China was finished and published. The atlas will fill the blanks in national basic scale thematic maps,and the geomorphologic database could be applied widely in many fields in the future.展开更多
文摘提出了1 000 k V交流输电系统提高输电能力,降低成本的参数优化模型,分析了1 000 k V与±800 k V输电系统技术经济性,以中国示范工程数据为基础估算了它们的建设成本,提出了改进的年运行成本法和稳定性成本法并用于1 000 k V与±800 k V输电系统技术经济评估。1 000 k V和±800 k V输电系统,输电距离1 500±2 000 km,按静态(热)稳定输送功率,单位输电建设成本处于相同水平;1 000 k V输电系统的年运行成本明显低于±800 k V输电系统。1 000 k V输电系统暂态稳定输送功率的单位输电建设成本也明显低于±800 k V输电系统。1000 k V输电系统经济性优于±800 k V输电系统。
基金Project supported by the National Natural Science Foundation of China (No. 40471081)the Frontal Field Project of the Chinese Academy of Sciences (No. ISSASIP0201) the Key Innovation Project of Chinese Academy of Sciences (No.KZCX3-SW-427).
文摘Soil classification is the foundation for exchange and extension of research findings in soil science and for modern management of soil resources. This study explained database and research methodology to create a cross-reference system for translating the Genetic Soil Classification of China (GSCC) into the Chinese Soil Taxonomy (CST). With the help of the CST keys, each of the 2 540 soil species in GSCC has been interpreted to its corresponding soil order, suborder, great group, and sub-group in CST. According to the methodology adopted, the assigned soil species have been linked one another to their corresponding polygons in the 1:1000000 digital soil map of China. Referencibility of each soil species between the GSCC and CST systems was determined statistically on the basis of distribution area of each soil species at a high taxon level of the two systems. The soils were then sorted according to their maximum referencibility and classified into three categories for discussion. There were 19 soil great groups in GSCC with maximum referencibility > 90% and 22 great groups between 60%-90%. These soil great groups could serve as cross-reference benchmarks. There were 19 great groups in GSCC with maximum referencibility < 60%, which could be used as cross-reference benchmarks until new and better results were available. For these soils, if the translation was made at a lower soil taxon level or on a regional basis, it would improve their referencibility enabling them to serve as new cross-reference benchmarks.
基金Foundation： Key Project of the National Natural Science Foundation of China, No.40871177 No.40830529
文摘Geomorphologic maps are one of the most fundamental materials of the natural environment. They have been widely used in scientific research,resource exploration and extraction,education and military affairs etc. An editorial committee was established in 2001 to collect materials for researching and compiling a set of new 1：1,000,000 geomorphologic atlas of China. A digital geomorphologic database was created with visual interpretation from Landsat TM/ETM imageries and SRTM-DEM etc. The atlas compiled from the database was finished. The main characteristics of the atlas are as follows：Firstly,Landsat TM/ETM imageries,published geomorphologic maps or sketches,geographical base maps,digital geological maps,and other thematic maps were collected,which were uniformly geometrically rectified,clipped into uniform sheets,and stored in the foundation database. Secondly,based on the legends of 15 sheets 1：1,000,000 maps published in the 1980s,a geomorphologic classification system was built by combining morphology and genesis types. The system comprised seven hierarchical layers：basic morphology,genesis,sub-genesis,morphology,micro-morphology,slope and aspect,material composition and lithology. These layers were stored in the database during visual image interpretation. About 2000 kinds of morpho-genesis and 300 kinds of morpho-structure were interpreted. Thirdly,the legend system was built,which included color,symbol bases and note bases etc.,compilation standards and procedures were developed,74 sheets of 1：1,000,000 covering all land and sea territories of China were compiled,the 1：1,000,000 geomorphologic atlas of the People＇s Republic of China was finished and published. The atlas will fill the blanks in national basic scale thematic maps,and the geomorphologic database could be applied widely in many fields in the future.
