杠杆规则 (lever rule): (1)式与(2)式相等： DXA+DgXA = nKA+ngX⅓8 (XA-XA) =ng(XA -XA) (3) 1+g PB 0 XA X4X8 XpB * pA * x A 0 p l+g, L G H xA xA l xA g 杠杆规则 (lever rule): (1)式与(2)式相等: nlxA+ngxA = nlxA l + ngxA g nl ( xA－xA l ) = ng ( xA g－xA) (3)