Math S.J.T.0. Phase Transformation and Applications ·Total differential 2=f(x,y) 0 a), Euler Stiring approximately equation lnW！≈WlnW-W SJTU Thermodynamics of Materials Spring 2009 ©X.J.Jin Lecture 1 First law I 10/38Phase Transformation and Applications S. J. T. U. SJTU Thermodynamics of Materials Spring 2009 © X. J. Jin Lecture 1 First law I 10/38 Math • Total differential ln N! N ln N  N • Stiring approximately equation   1          z y x zy xz yx x y z y z x z x y             Euler z  f (x, y)