4.吉布斯函数(自由焓)G=H-7S=F+p dG=-SdT+vdp G=G(,p),dG=/oG aG dtt dp aT P aG aG S =S(T,p)2 y(T, p) aT P丿 a2G aG aS apot oTop aT H=G+TS=G-TaG G aG U=H-pV=G aT OT4. 吉布斯函数（自由焓） dG = −SdT +Vdp p p G T T G G G T p G p T ( , ), d d d            +        = = ( , ), V (T, p) p G S T p V T G S p T =            = =        = − T p G p T G    =    2 2 G = H −TS = F + pV T p G H G TS G T         = + = − p T p G p T G U H pV G T            −        = − = − T T p V p S         = −          