Carnot cycle(8) S.J.T.U. Phase Transformation and Applications Isothermal Adiabatic Isothermal Adiabatic A->B B->C C->D D->A ∑ C(T-T2)<0 W -R,n5<0 Vy7 RTln Vs C(T2-T)>0 R(T-T2)I V2.0 V 9 RT2 In V2,0 V320 R(T-T) △U 0 Cr(T-T2)<0 0 C(-T)>0 0 +9 =0 y Va L T SJTU Thermodynamics of Materials Fall 2010 ©X.J.Jin Lecture 4 Second law llPhase Transformation and Applications S. J. T. U. SJTU Thermodynamics of Materials Fall 2010 © X. J. Jin Lecture 4 Second law II Carnot cycle (8) W ln 0 3 4 1  V V Q ln 0 RT 1 2 2  V V RT ln 0 1 2 − 2  V V RT U 0 A->B B->C C->D D->A 0 Isothermal Adiabatic Isothermal Adiabatic ln 0 3 4 − 1  V V RT 0 0 ( ) 0 CV T1 −T2  ( ) 0 CV T2 −T1  ( ) 0 CV T1 −T2  ( ) 0 CV T2 −T1   0 ( )ln 0 1 2 1 − 2  V V R T T ( )ln 0 1 2 2 − 1  V V R T T Q2 Q1 0 1 1 2 2 + = T Q T Q 4 3 1 2 V V V V =