完全互溶的双液系在一定条件下发生相变而成为部分互溶体系.六十年代,李俊甫等曾研究过盐的加入对相变条件的影响,提出了线性方程:T=T_0+Kx_x。(T_0,T分别为双液比固定时加盐前后体系的相变温度,x_s为盐的摩尔分数,K为常数).但至今尚无人从理论上证明其存在并加以计算.本文试从微扰理论出发证明该线性方程成立,并对部分体系进行计算。 In the 1960s, Li Junfu et al. Studied the effect of salt addition on the phase transition conditions, and proposed a linear equation: T = T_0 + Kx_x. (T_0, T are respectively the phase transition temperatures before and after the addition of salt in the two-liquid ratio, x_s is the mole fraction of salt, and K is a constant.) However, no one has theoretically proved its existence and calculated. Perturbation theory proves that the linear equation is established, and some systems are calculated.