在球极坐标系中 立.=0cw0g ò (5.6) 0 M.=-ih 12 (5.7) 在球极坐标系中              = −   −   = −   +   =       M i M i M i z y x (cos cot sin ) (sin cot cos ) ] sin (sin ) sin [ 2 2 2 2 2 1 1         +     = −  M  (5.6) (5.7)