M=N-D+w N=NA 将J4=-DB4和N=M代入N4=J4+N4 dc dc C dz 若扩散在气相中进行,则: PA A RT RT 2021/2/21 上页下及2021/2/21 C c N C c N N B A A = + N = NA 将 dz dc J D A A = − AB N = NA 和 代入 C c N J N A A = A + dz dc C c DC N A A A − = − 若扩散在气相中进行，则： RT p c A A = RT P C =