On Gibbs free energy S.J.T.U. Phase Transformation and Applications -ohw=-oW +oW w T T 8Q=dUU-δW dS≥ actual T 2=adU+p外dV-oW Tas-dU-pdW之-o 有效功 SJTU Thermodynamics of Materials Spring2010©X.J.Jin Lecture 6 Property Relation llPhase Transformation and Applications S. J. T. U. SJTU Thermodynamics of Materials Spring 2010 © X. J. Jin Lecture 6 Property Relation II On Gibbs free energy lw  Wrev W T lw T Q dS  actual    T Q dS  actual  Q  dU  p 外dV W' TdS  dU  p 外dV  W' Q  dU W 有效功