141=0i=2,…,n h1>0 为酉矩阵 12 In =0 10 vn2类推p=En 2 nn Ri=Rvi1 l 11 = 0 i = 2,  , n l 11  0 0 21 1 = = = n v  v             = n nn n v v v v V        2 22 2 0 0 1 0 0 V为酉矩阵 1, 0 v11 = v12 == v1n = 类 推 V = En U1 = U2 R1 = R2