Not enough is known about these forces to yield acourate theoretical expressions for the virial coefficients. 要想得到维里系数的准确理论表达式，我们还缺乏关于这些力的足够知识。
The third virial coefficients of humid air are estimated with the equation of corresponding state with four characteristic parameters. 对水蒸汽和湿空气的第三维里系数也进行了预估计算。
