let hod 圆内 Poisson方程第一边值问题Gren函数 V2G(r;r)=-6(r-r)r<a,|r1<a 0 G(r;r) 0 T=a 其中 72=2+y2V3=2202 ax2 ay2Green Function of Helmholtz Eq ... Green Functions for Time-Dependent Problems Separation of Variables Method of Images SPoisson§1>Š¯KGreen¼ê ∇2 2G(r; r 0 ) = − 1 ε0 δ(r − r 0 ) |r| < a, |r 0 | < a G(r; r 0 )   r=a = 0 Ù¥ r 2 = x 2 + y 2 ∇2 2 = ∂ 2 ∂x2 + ∂ 2 ∂y2 C. S. Wu 1›8ù Green¼ê()