四个特性函数(吉布斯方程) Gibbs equation du=Tds-pdv u=f(s,v) dh=Tds+vdp h=h(s,p) df =-sdT-pdv f=f(T,v) dg=-sdT+vdp g=g(T,p)四个特性函数(吉布斯方程) Gibbs equation du Tds pdv u f s v = − = ( , ) dh Tds vdp h h s p = + = ( , ) df sdT pdv f f T v = − − = ( , ) dg sdT vdp g g T p = − + = ( , )