Wnc=-p△V+Wm Or =T AS .:么U=TS-pAV+Wm △U+pAV=T△S+W'mx △H=TAS+Wmx AH-T AS=W'max 令G=H-TS, 则△G=Wmax G:定义的新函数，自由能函数，Free energy Wmax= - p V + W max, Qr = T S  U = T S - p V + W max, U + p V = T S + W max, H = T S + W max, H - T S = W max 令 G  H - TS, 则 G = W max G：定义的新函数，自由能函数，Free energy