物理化学学报 >> 1986, Vol. 2 >> Issue (06): 560-568.doi: 10.3866/PKU.WHXB19860613

研究论文 上一篇    下一篇

从统计力学推导流体状态方程——方阱势硬球微扰理论的解析表达式

张秉坚; 侯虞钧   

  1. 浙江大学化工热力学研究室
  • 收稿日期:1985-02-08 修回日期:1986-06-14 发布日期:1986-12-15

DERIVATION OF EQUATION OF STATE FOR FLUIDS FROM STATISTICAL MECHANICS——A NEW ANALYTIC REPRESENTATION OF SQUARE-WELL POTENTIAL HARD SPHERE PERTURBATION THEORY

Zhang Bingjian; Hou Yujun   

  1. Zhejiang University; Hangzhou
  • Received:1985-02-08 Revised:1986-06-14 Published:1986-12-15

摘要: 本文在Zwanzlg微扰理论的基础上, 对二级以上的高级微扰项采用Barker与Henderson的近似方法, 得到一个简单的微扰理论表达式。以硬球势为参考势, 方阱势为微扰势,用一新的级数表达式g(R)=1/ηgj(η/(1-η))~j为径向分布函数, 导出了自由能。内能、比热、压缩因子的级数表达式。为了检验理论的正确性, 取g(R)级数的前四项代入各热力学性质的表达式, 与Monte-Carlo(MC)及分子动力学(MD)计算机模拟数据作了比较, 结果符合较好。

Abstract: A simple and accurate analytic representation of square-well potential hard sphere perturbation theory is derived based upon the Zwanzig perturbation method. The higher-order perturbation terms are obtained by using the Barker-Henderson approximation. A new form of radial distribution function g(R)=1/ηgj(η/(1-η))~j is proposed and applied. The theory is tested by calculating thermodynamic properies with the four-term truncated form of the (η/(1-η)) expansions and compared with available Monte Carlo and Molecular Dynamics computer simulation calculations. The results are in good agreement.