又K,=PrPo,故po,= KpPH2o PH2O PH2 所以r= k PnoPco-k2Pn Pcoz Pn,+bpn.oH H O H O CO H CO H p H O O H O H O p p bp k p p k p p r p K p p p p p K 2 2 2 2 2 2 2 2 2 1 2 ( ) ( ) , + − = = =   所以 又 故