摘要
本文从热力学定律出发，对系统内能依赖于温度的条件。
Starting from the laws of thermodynamics,the problems about the conditions of th e temperature dependence of internal energy and about the directions of quasi s tationary cyclic processes have been analyzed and discussed in this paper.
关键词
热力学定律
内能
循环方向
thermodynamics
internal energy
direction of a cyclic process
