2009年，根据迈克尔·刘易斯的作品《弱点：比赛进程》而改编的电影《弱点》被搬上大屏幕，该片讲述了2009年美国国家橄榄球联盟（National Football League）首轮选秀球员迈克尔·奥赫由丑小鸭蜕变成白天鹅的传奇而不凡的经历...2009年，根据迈克尔·刘易斯的作品《弱点：比赛进程》而改编的电影《弱点》被搬上大屏幕，该片讲述了2009年美国国家橄榄球联盟（National Football League）首轮选秀球员迈克尔·奥赫由丑小鸭蜕变成白天鹅的传奇而不凡的经历。该剧剧情真实感人，最终取得三亿美元的票房成绩。本文通过对安徒生的童话故事《丑小鸭》和电影《弱点》的比较分析和论述，得出了一些发人深省、值得回味的观点和结论。展开更多
A power flow analysis method for weakly looped distribution systems with PV buses is proposed in this paper. The proposed method is computationally more efficient and more robust compared with the conventional compens...A power flow analysis method for weakly looped distribution systems with PV buses is proposed in this paper. The proposed method is computationally more efficient and more robust compared with the conventional compensation methods. The robustness is achieved by embedding the boundary conditions of loops and PV buses into the Jacobian matrix. The computational efficiency is achieved by the carefully designed factorization of Jacobian matrix. Test results on a 33 bus system are presented.展开更多
Using remote sensing(RS)data and geographical information system(GIS),eco-environmental vulnerability and its changes were analyzed for the Yellow River Basin,China.The objective of this study was to improve our under...Using remote sensing(RS)data and geographical information system(GIS),eco-environmental vulnerability and its changes were analyzed for the Yellow River Basin,China.The objective of this study was to improve our understanding of eco-environmental changes so that a strategy of sustainable land use could be established.An environmental numerical model was developed using spatial principal component analysis(SPCA)model.The model contains twelve factors that include variables of land use,soil erosion,topography,climate,and vegetation.Using this model,synthetic eco- environmental vulnerability index(SEVI)was computed for 1990 and 2000 for the Yellow River Basin.The SEVI was classified into six levels,potential,slight,light,medium,heavy,and very heavy,following the natural breaks classification. The eco-environmental vulnerability distribution and its changes over the ten years from 1990 to 2000 were analyzed and the driving factors of eco-environmental changes were investigated.The results show that the eco-environmental vulnerability in the study area was at medium level,and the eco-environmental quality had been gradually improved on the whole.However,the eco-environmental quality had become worse over the ten years in some regions.In the study area,population growth,vegetation degradation,and governmental policies for eco-environmental protection were found to be the major factors that caused the eco-environmental changes over the ten years.展开更多
文摘2009年，根据迈克尔·刘易斯的作品《弱点：比赛进程》而改编的电影《弱点》被搬上大屏幕，该片讲述了2009年美国国家橄榄球联盟（National Football League）首轮选秀球员迈克尔·奥赫由丑小鸭蜕变成白天鹅的传奇而不凡的经历。该剧剧情真实感人，最终取得三亿美元的票房成绩。本文通过对安徒生的童话故事《丑小鸭》和电影《弱点》的比较分析和论述，得出了一些发人深省、值得回味的观点和结论。
文摘A power flow analysis method for weakly looped distribution systems with PV buses is proposed in this paper. The proposed method is computationally more efficient and more robust compared with the conventional compensation methods. The robustness is achieved by embedding the boundary conditions of loops and PV buses into the Jacobian matrix. The computational efficiency is achieved by the carefully designed factorization of Jacobian matrix. Test results on a 33 bus system are presented.
基金the National Key Basic Research Support Foundation of China(973 Program)(No.2005CB422003)the National Natural Science Foundation of China(No.40571037)
文摘Using remote sensing(RS)data and geographical information system(GIS),eco-environmental vulnerability and its changes were analyzed for the Yellow River Basin,China.The objective of this study was to improve our understanding of eco-environmental changes so that a strategy of sustainable land use could be established.An environmental numerical model was developed using spatial principal component analysis(SPCA)model.The model contains twelve factors that include variables of land use,soil erosion,topography,climate,and vegetation.Using this model,synthetic eco- environmental vulnerability index(SEVI)was computed for 1990 and 2000 for the Yellow River Basin.The SEVI was classified into six levels,potential,slight,light,medium,heavy,and very heavy,following the natural breaks classification. The eco-environmental vulnerability distribution and its changes over the ten years from 1990 to 2000 were analyzed and the driving factors of eco-environmental changes were investigated.The results show that the eco-environmental vulnerability in the study area was at medium level,and the eco-environmental quality had been gradually improved on the whole.However,the eco-environmental quality had become worse over the ten years in some regions.In the study area,population growth,vegetation degradation,and governmental policies for eco-environmental protection were found to be the major factors that caused the eco-environmental changes over the ten years.
