G=4 C1=0.521=0 a12=-0.9a2=-0.8 =02y1=0 12 0.3 则并联结构: 0.2y(m) 0.5 -0.9Q3 -0.8 图P5-3则并联结构： 0 G = 4 11 = 0.5 21  = 0 01  = 0.2 11  = 0 12  = −0.9 22  = −0.8 02  =1 12  = 0.3