Research on Simulation Methods of Electric Field Intensity on Surface of 10 kV Cable Joint

The electric field intensity (EFI) is important characteristic quantity for evaluating the internal insulation state of cable joints. Based on finite element method, this paper proposes two EFI research methods, field-circuit coupling method and equivalent circuit method. The average EFI of the inner surface of the outer semi-conducting shield can be calculated from the current in the measuring circuit. The relative error between these two methods is about 15%, which roughly proves the consistency of the two methods. Further practical application research enables online monitoring of cable joints.

中国商业银行的生产效率和全要素生产力变化探析

本文应用数据包络分析方法,探讨了中国商业银行的生产效率和全要素生产力变化。基于2005—2009年的面板数据,以15家主要商业银行为例,本文采用关于投入-产出变量选择的两种模式,分别对中国商业银行的生产效率和全要素生产力变化进行了测评。结果表明,自2005年以来,特别是在2008—2009年,中国商业银行整体的生产效率水平得到了提高,其全要素生产力得到了提升。同时,本文还对国家控股的大型商业银行和全国性的股份制商业银行这两类银行的效率和指数变化进行了比较分析。