中文摘要：

拟解析近似方法是一种解决电磁场散射问题的快速求解积分方程的近似方法，它绕开了传统数值方法中的求解大型代数方程组或大型矩阵问题，适用于强散射和大扰动问题。本文应用孙建国提出的求解异常电场积分方程的张量拟解析近似理论公式，研究用其求解直流电场积分方程。利用接近实际的地电模型对异常电场进行模拟，研究了均匀场中异常球体的张量拟解析近似解；并对均匀场中的立方体异常体进行了数值计算。效果良好并具有很高的计算速度。研究结果为三维直流电场快速正反演模拟打下基础。

英文摘要：

The quasi-analytical method is a fast way used to solve integration equations about electromagnetic scattering problems, and is applicable to the strong scattering or large perturbation problems. In this paper the tensor quasi-analytical method for anomalous electric field which was introduced by Sun in 2005, is applied to the D. C. electrical field. The tensor quasi-analytical method about the anomalous spherite in the uniform field is studied, and the models which are approaching the reality are selected. The anomalous electric field caused by anomalous cube in the uniform field is calculated also. It is proved that the results is good and the method is precisional with high speed. It paves way for the quasi-analytical method using in forward and inverse modelings of 3D D.C. electrical field.