中文摘要：

给出了矿井全空间瞬变电磁场的时域有限差分法（FDTD）算法，并推导了Mur吸收边界条件．利用Mur吸收边界条件，选用均匀全空间电偶极源作为初始激发源，模拟了均匀介质中巷道底板岩层内部和层状介质中三维低阻异常体的全空间响应特性，分析了瞬变电磁场在均匀介质中1．9μs和27．6μs两时刻的传播规律及在层状介质中1．2μs和0．023ms两时刻的传播规律．结果表明：巷道对电场的影响在初期并不明显，在20μs后才表现出来；瞬变场能较好地分辨低阻层，对高阻层的穿透能力强，并且对低阻体反映灵敏；吸收边界条件只有在场域较大、网格节点较多时才能产生明显的效果．所研究成果为矿井瞬变电磁法资料的解释提供了理论依据．

英文摘要：

A 3D finite difference time domain （FDTD） solution was presented and Mur absorbing boundary condition was deduced. The whole-space response characteristics for three dimensional conductive body located in the floor of the mine drift either in homogeneous medium or in layered medium was simulated, with using Mur absorbing boundary condition and taking a electrical dipole source in homogeneous whole space as a initial source; the diffused regularity of the transient field in homogeneous medium at 1.9μs and 27.6μs,and in layered medium at 1.2μs and 0. 023 ms was discussed. Simultaneously, the results indicate that, it is not visible to electric field affected by laneway at early times, this influence displays after 20 μs; transient field has a high resolution capability to low-resistivity layer, and also has a high penetrative capability to high-resistivity layer; Therefore, it is sensible to low-risistivity body; Mur absorbing boundary condition can achieve better results in a big modeling region and more grid elements. This provides a theoretical basis for the interpretation of TEM measurement in mine.