中文摘要：

溶液的表面吸附仍是表面热力学当中的一个具有挑战性的问题.在本文中我们定义了一个新的热力学态函数,表面吸附的平衡条件是这个态函数的微分为零.基于这个条件,我们推导了描述平衡时表面吸附的新方程.在推导过程中没有采用假想分界面.新的表面吸附方程和Gibbs表面吸附方程完全不一样.还通过分子动力学方法模拟了氯化钠溶液,模拟结果和我们的理论预测符合较好.

英文摘要：

Surface adsorption of a solution is still a challenging problem in the thermodynamics of surfaces. In this work, a new thermodynamic state function is defined. The equilibrium condition of surface adsorption is that the differential of this state function is equal to zero. Based on this condition, we derived a new equation to describe surface adsorption at equilibrium. No hypothetical dividing surface is needed in this derivation. The new equation is quite different from the Gibbs adsorption equation. We also performed molecular dynamic simulations of aqueous sodium chloride solutions. The simulated results are in good agreement with our theoretical predictions.