I区:F_D q E lee r r D I区:E q 2 4兀 0 0 由U。=Ed= edr I区 高斯面 R u= Edr+ e, dr r q q + R 4 元CEr 4e 4re 8 rR) R I区:U eadr 4 兀CnT 0 4 兀C 09 I区: r D E 0 1 1 = II区: 2 4 0 r q r = r D E 0 2 2 = 2 4 0 r q = r E0 == E 0 = a a U E dl 由 = a Edr = + R Rr U E dr E dr 1 1 2 dr r q dr r q R Rr r = + 2 0 2 4 0 4 I区: Rq r R q0 r 4 0 1 1 4 + = − = r U E dr 2 2 dr r q r = 2 4 0 r q 4 0 II区: = r I IIR q rr 高斯面