【摘要】 为深入认识汽液界面现象 ,解释汽液界面的独特性质 ,采用分子动力学模拟方法从分子水平上研究了 L ennard-Jones流体汽液界面。模拟结果表明 ,汽液界面实际上是一个随时间涨落的起伏不平的曲面 ;汽液过渡区就是该曲面的涨落区域 ;汽液相变是一个突变的过程 ;汽液界面体系内密度、压力张量及温度等热力学量连续变化只是统计的结果。并在此认识基础上 ,从汽液分子相互转化的微观行为解释了汽液界面的温度分布中的尖峰和低谷出现的原因。在分子的汽液相变过程中 ,从液相向气相的转化发生在汽液界面的波峰处的几率最大 ,而从气相向液相的转化发生在汽液界面的波谷处的几率最大更多还原

【Abstract】 Molecular dynamics simulations were performed using the Lennard Jones potential to investigate the liquid vapor interface of argon to further understand the interface phenomenon and to interpret the characteristics of the liquid vapor interface. The study indicated that the liquid vapor interface is actually a wavy surface varying with time and the transition region is the undulating region of the liquid vapor interface. The phase change between the liquid and the vapor is regarded as a discontinuity. The continuous variation of the density, the pressure tensor and the temperature are statistical results. Furthermore, the sharp peak and the little valley in the local temperature profile at the liquid vapor interface are interpreted using the undulant interface structure. The liquid molecule at the interface wave crest has a larger probability of breaking away the liquid film and moving into the vapor. However, vapor molecules in the trough of the wavy interface can be much more easily absorbed by the liquid film into the liquid.更多还原