=D+nE丛g°+o RTinp9 E P =n业v'+E丛E°+n RTLnp9+n:RTLnp9 nD RTLnyp+nE RTLnyE Pa-PyB =nDμD°(T,P)+nEμE°(T,P) RT(npLnyp+neLnyE) (nn°-5)μD(T,P)+5LE°(T,P)+AG AG=RT(mpLnyp+ngLnye) 77 = nD μD °+ nE μE °+ nD RTLn  P PD + nE RTLn  P PE = nD μD °+ nE μE °+ nD RTLn  P P + nE RTLn  P P + nD RTLnyD + nE RTLnyE = nD μD °(T,P)+ nE μE °(T,P) + RT(nD LnyD + nE LnyE ) =( nD °- )μD θ(T,P)+  μE θ(T,P)+  Gmix  Gmix= RT(nD LnyD + nE LnyE ) PB =PyB