Abstract: The pressures of normal gases, hydrocarbons, freon, ammonia and water in the superheated rapor region and the entropies of normal gases, hydrocarbons, freon which dose to the saturated vapor line were calculated with perturbation theory. The calculated results were in good agreement with the values reported in literature, which also showed that the calculating method is of certain generality and practical value.

摘要： <正>微扰理论将一个具有分子间相互作用的位能E。（r”,/）的实际系统看作是位能为Ez”厂N,/）的参考系统的微扰系,即E;‘’一E。一氏”,E;1’为位能的微扰项。实际系统的自由能等其它性质,可围绕参考系统相应性质展开为Taylor级数,微扰展开项只涉及Ez“和参考系统的分布函数