二元Lenard-Jones流体混合物的桥函数  

A New Bridge Function for Binary Lenard-Jones Mixture

作　　者：储浚[1] 林伟[1] 马翔[1] 

机构地区：[1]中国石油大学物理科学与技术学院,山东东营257061

出　　处：《西南师范大学学报（自然科学版）》2009年第2期21-25,共5页Journal of Southwest China Normal University(Natural Science Edition)

摘　　要：衡量桥函数近似准确程度的重要标志是其计算出的热力学量能否较好地满足热力学自恰性,本文提出了一个新的用于研究二元Lenard-Jones流体热力学性质的桥函数,该桥函数的函数形式采用修正Verlet桥函数形式,其宗量为间接相关函数与含密度和温度及浓度的微扰势之差,在高于临界温度的区域(约化温度从1.5到5、约化密度从0.01到0.89),对三不同的浓度(摩耳分数分别为0.125,0.5,0.875)分别用维里方程和压缩率方程计算了二元Lenard-Jones流体混合物的约化压强,计算结果表明,利用本文提出的桥函数计算得到的结果具有良好的热力学自恰性.通过引入含密度和温度及浓度的微扰势可以改善计算结果的热力学自恰性,从而提高计算其他热力学量的准确性.Whether the bridge function approximation used for calculating thermodynamics properties of liquids by O-Z equations is correct enough depends on the consistent extent of thermodynamics quantities calculated by Virial route and compressibility route respectively. This paper proposes a new bridge function for LJ binary mixture which has the same form as modified Verlet bridge function with its independent variable be replaced by the difference between indirect correlation function and perturbation potential modified by temperature and density as well as concentration. The reduced pressure calculated by both Virial e- quation and compressibility equation shows good agreement over the range of reduced temperature （from 1.35 to 5） and reduced density（from 0.01 to 0.89） in concentration 0. 125 and 0.5 as well as 0. 875. This work improves thermodynamics consistency of pressures compared to the result calculated by using Choudhury＇ s and Duh＇ s bridge function.

关 键 词：二元LJ流体混合物 积分方程理论 桥函数 热力学自恰性 

分 类 号：O469[理学—凝聚态物理]