Ising格子流体相平衡的Monte　Carlo模拟

Phase Equilbria of Ising Lattice Model from Monte Carlo Simulations

将带空穴偏倚取样的Ｗｉｄｏｍ插入粒子法应用于Ｉｓｉｎｇ格子模型，求得了Ｉｓｉｎｇ格子流体在不同温度、不同密度下的剩余化学位，并通过热力学关系求得了系统的化学位、压力和压缩因子；计算了系统的内能涨落与温度的关系，并据此求得了系统在临界点附近的比热尖峰。最后根据相平衡原理，获得了系统的汽液平衡相图。模拟所得的结果与Ｓｃｅｓｎｅｙ的级数解及Ｆｌｏｒｙ－Ｈｕｇｇｉｎｓ理论进行了比较，表明本文的模拟结果与Ｓｃｅｓｎｅｙ的准确结果十分接近。

The Widom's test-particle-method is modified and applied to the Ising model to calculate the residual chemical potentials at various temperatures and densities.Other thermodynamic propertie of the system,such as chemical potentials,pressures and compressibility factors are calculated through the thermodynamic relationship,and the vapor-liquid phase equilibrium is obtained according to the equilibrium criteria.The heat capacity is also calculated from the fluctuation of energy,and a peak is observed near the critical temperature.Results are compared with those from Flory-Huggins'theory and those from Scesney's Pade coefficients,The results of this work shows good agreement with those from Scesney's work.