柱面坐标中的散度：$\operatorname{div}a=\frac{1}{r}\frac{\partial(ra_r)}{\partial r}+\frac{1}{r}\frac{\partial a_\theta}{\partial\theta}+\frac{\partial a_z}{\partial z}$；球面坐标中的散度：$\operatorname{div}a=\frac{1}{r^2}\frac{\partial(r^2a_r)}{\partial r}+\frac{1}{r\sin\theta}\frac{\partial(a_\theta\sin\theta)}{\partial\theta}+\frac{1}{r\sin\theta}\frac{\partial a_\varphi}{\partial\varphi}$。

出处：29