Simulation results along the sub critical isotherms show characteristics of a smooth small system loop in the gas/ liquid phase transition region, which is similar to the known loop like isotherm in the solid/ liquid phase transition region. 沿等温线的模拟结果显示了在气/液相转变区内系统状态连续变化的特征,与固/液相转变区的状态变化趋势相同。