The divergence theorem links a surface integral to a volume integral.
散度定理把曲面积分与体积分联系起来。
Using the divergence theorem, we can convert the flux through a closed surface into an integral of the divergence over the enclosed region, which simplifies many electromagnetism problems.
利用散度定理,我们可以把闭合曲面的通量转化为对包围区域内散度的积分,从而简化许多电磁学问题。