熵、巨势与开放的近平衡系统热力学第二定律的两种表现形式

ENTROPY,GRAND POTENTIAL AND TWO KINDS OF FORMALISMS OF THE SECOND LAW OF THERMODYNAMICS IN OPOEN SYSTEMS CLOSE TO EQUILIBRIUM

从分析局域平衡理论框架内封闭热力学系统之熵产生与特性函数变率的关系入手，阐明了非平衡态的热力学特征，即非负耗散强度及非平衡线性区向最小耗散态演化的趋势，实际上是分别体现在热力学势的一阶及二阶变率层次上的状态演化方向。同时，提出了以巨势为基础的开放非平衡系热力学第二定律的表述形式，论证了在近平衡区与最小熵产生原理的等价关系。

Begining with a complete analysis of the relation between the entropy production andthe time- derivative of the characteristic functions of closed thermodynamic systems based on thelocal equilibrium postulate,it is clarified that the well-known thermodynamic chatacters ofnonequlilbrium states , both the non-negative dissipative intensity and the tendency towards tominimum dissipation state in the linear nonequilibrium region are actually identical with the state-evolution direction respectively on the levels of the lst and 2nd order time-derivatives of thethermodynamic potentials. A new formalism of the 2nd law of thermodynamics of opennonequilibrium systems is suggested by means of the grand potentials meanwhile its equivalence withthe minimum entropy production principle in the linear nonequilibrium region is also discussed, thearguments formed in this paper can be valid for the systems in external fields.