Bosonic and fermionic entropy of black holes with different temperatures on horizon surface

By using the method of quantum statistics, we derive directly the partition functions of bosonic and fermionic field in the black hole space－time with different temperatures on horizon surface. The statistical entropy of the black hole is obtained by an improved brick-wall method. When we choose a proper parameter in our results, we can obtain that the entropy of the black hole is proportional to the area of horizon. In our result, there do not exist any neglected term or divergent logarithmic term as given in the original brick-wall method. We have avoided the difficulty in solving the wave equation of the scalar and Dirac field. A simple and direct way of studying entropy of the black hole is given.     

关于电容器的一组演示实验

在高中物理电容器的教学中,我们设计并安排了一组用大型示教万用电表组装的电容器演示实验。该实验取材容易、效果明显,能使学生加深对电容概念和物理意义的理解,增强对电容器串、并联时总电容改变的感性认识。一、演示装置装置如图所示。G、V表是目前学校中常用的大型示教万用电表(苏州电表厂出