8 17-5 Some Special Cases of The First Law of Thermodynamics(P409-417) 1. Isothermal ( Constant-Temperature) Process:P409 The process carried out at constant temperature 特征=常量 过程方程p=常量 M i △ R△TdU=0 RT Or=w=n dv= nRT hn nRT In p1§ 17-5 Some Special Cases of The First Law of Thermodynamics (P409-417) 1. Isothermal (Constant-Temperature) Process: P409 The process carried out at constant temperature. dU = 0 特征 T = 常量 过程方程 pV = 常量 R T M i U =   2 = = =  V V RT Q W n V V T d 2 1 1 2 V V nRT ln 2 1 p p = nRT ln