Abstract: Based on the stability theory of a multicomponent system, the criteria of spinodal and critical point for the mixture consisting of one discrete component and one polydispersed component described in the equation of state are derived If the continuous components are regarded as an intuitive single component, the criteria can be divided into two parts: the first part is the same as the criteria of a binary system, the second one is related to the distribution of polydispersed component The van der Waals equation of state is used to calculate the critical loci of an intuitive system The influence of average molecular weight and its dispersity on the critical phase behavior is examined

摘要： 从多元混合物的稳定性理论出发 ,建立了基于状态方程的由一个离散组分和一个连续分布组分组成的混合物的临界点和旋节面判椐 .若将连续分布组分看作单一的虚拟组分 ,这些判据可分成两项 ,第 1项与二元系的判别式相同 ,仅与均值有关 ,第 2项则与分布有关 .用vanderWaals状态方程计算了一假想物系的临界点 ,考察了平均相对分子质量和分散度对临界曲线的影响 .