(2)0<<0 Z(ol ≠0N12≠0 < 0(j) B<B2W1=90 0(/o)<90 2(0 97 0 0 (2)      =    ( ) ( ) 90 90 0 0 0 0 1 2 1 1 2 1 1       Z j j M M z N  1 z 1 p p2 0 Z( j)  0  0 90 0 −90( j) N1 j