1 Equivalence Relations 【Definition】A relation R is defined on a set S if for every pair of elements (a, b), a, b S, a R b is either true or false. If a R b is true, then we say that a is related to b
“In this world nothing is certain but death and taxes.” . . . Benjamin Franklin 0 20 40 60 80 100 1789 Taxes paid in Ben Franklin’s time accounted for 5 percent of the average American’s income
6.1 Basic conceptions (基本概念) 6.2 Phase change Process of Pure Substance (纯质的 相变过程) 6.3 Property Tables (水蒸气性质表) 6.4 h-s diagrams for Water Vapor (水蒸气的h-s图) 6.5 Thermodynamic Processes of Water Vapor (水蒸气的热力过程)