efficiency of engine:Understand the different statements of the second law. 2.Key points Statement of the second law,entropy 3.Content 3.1 Carnot cycle Work and heat in each step of Camnot cycle 3.2 The second law Statements of the second law 3.3 Reversible engine: Efficiency of reversible engines 3.4 Entropy: Definition of entropy 3.5 Application of the second law: The change of entropy in reversible processes.the entropy of dieal gas 4.Teaching method Talk and discussion 5.Evaluation Assignment. Chapter3 Thermodynamic potentials 1.Purpose Understand the definitions and their roles of thermodynamic potentials 2.Key points: Enthalpy;Free energy:Maxwell relations 3.Content 3.1 Thermodynamically potentials: Internal energy.entropy.Free energ 3.2 Maxwell relations: Derive the Maxwell relations 4.Teaching method 4 efficiency of engine; Understand the different statements of the second law. 2.Key points: Statement of the second law; entropy 3.Content 3.1 Carnot cycle Work and heat in each step of Carnot cycle 3.2 The second law Statements of the second law 3.3 Reversible engine； Efficiency of reversible engines 3.4 Entropy； Definition of entropy; 3.5 Application of the second law； The change of entropy in reversible processes; the entropy of dieal gas 4.Teaching method Talk and discussion 5.Evaluation Assignment. Chapter 3 Thermodynamic potentials 1.Purpose Understand the definitions and their roles of thermodynamic potentials 2.Key points: Enthalpy; Free energy; Maxwell relations 3.Content 3.1 Thermodynamically potentials： Internal energy; entropy; Free energy 3.2 Maxwell relations； Derive the Maxwell relations。 4.Teaching method