CA V。A C 100ns50(-c)s、l Ve=%n⑦O (3) aD B=V×A=0→)H=-B=0 V×H =0 at 0A aB e=vy at +e1=0 VⅹE= OX D=E=0 V·B=0 V·D=00 0 0 0 ( ) 0 0 1 1 Ax A c x c t c A t            = = = − = −     = −  1 0 0 1 0 0 x x B A H B A E e e t x D E     =  = → = =   = − − = − + =   = = 00 00 D H t B E t BD    = =    = − =   =  = (1) (2) (3)