r>a→>V2A1=0→ 1a nAzI 0 rOr、Or a,=D Inr +d 边界条件 B,=B, 〉V×A=V×A 2n Z =a→ H1=H2,→H12=H2…( 由式()得: OA aA O →D uoJoa Inr+D( ) ( ) 2 1 1 1 1 1 2 1 1 2 1 2 1 2 3 1 0 0 1 0 0 3 1 0 0 1 0 0 ln 1 1 1 1 3 3 1 ln 3 Z Z Z n n Z Z t t Z Z Z A r a A r r r r A D r D B B A A r a H H H H A A r r D J a D J a a A J a r D           →  = → =        = +  = →   =   = →   = → =     =   − = → = − = − + 边界条件 由式 得：