Frolkova Anastasia V
Lomonosov Institute of Fine Chemical Technologies, MIREA-Russian Technological University, 119454 Moscow, Russia.
Entropy (Basel). 2021 Dec 10;23(12):1666. doi: 10.3390/e23121666.
The study of topological invariants of phase diagrams allows for the development of a qualitative theory of the processes being researched. Studies of the properties of objects in the same equivalence class may be carried out with the aim of predicting the properties of unexplored objects from this class, or predicting the behavior of a whole system. This paper describes a number of topological invariants in vapor-liquid, vapor-liquid-liquid and liquid-liquid equilibrium diagrams. The properties of some invariants are studied and illustrated. It is shown that the invariant of a diagram with a miscibility gap can be used to distinguish equivalence classes of phase diagrams, and that the balance equation of the singular-point indices, based on the Euler characteristic, may be used to analyze the binodal-surface structure of a quaternary system.
相图拓扑不变量的研究有助于建立所研究过程的定性理论。对同一等价类中对象的性质进行研究，目的是预测该类中未探索对象的性质，或预测整个系统的行为。本文描述了气 - 液、气 - 液 - 液和液 - 液平衡图中的一些拓扑不变量。研究并说明了一些不变量的性质。结果表明，具有混溶间隙的图的不变量可用于区分相图的等价类，基于欧拉特征的奇点指数平衡方程可用于分析四元系统的双节线表面结构。
