M(S)z12(S)-z22(S)=R2 -M(-S)z12(S)+z22(S)=R2 M(S)z12(S)-M(-S)z12(S)=2R2 有： 2R2 22(s)=M(s)-M(-s) 2R2 M(s)MS)iM-9）-)）=R 22(s)=1 M(s)2R2 -R2 M(s)-M(-S) M(s)2R2R2[M(s)-M(-S)]R2[M(s)+M(-S)] M(S)-M(-S) M(s)-M(-S) M(s)-M(-S)( ) ( ) 2 ( ) 2 12 M s M s R z s    12 12 2 2 M(s)z (s)  M(s)z (s)  R  有： ( ) ( ) [ ( ) ( ) ] ( ) ( ) [ ( ) ( ) ] ( ) ( ) ( )2 ( ) ( ) ( )2 ( ) 2 2 2 2 2 22 M s M s R M s M s M s M s R M s M s M s M s M s R R M s M s M s R z s                  12 22 2 12 22 2 ( ) ( ) ( ) ( ) ( ) ( ) M s z s z s R M s z s z s R       22 2 2 ( ) ( ) ( ) 2 ( ) z s R M s M s R M s    