It actually has infinite planes of symmetry rotating around its center here.

它实际上有无限的对称平面围绕着它的中心旋转。

What if we add an equal magnitude, parallel, infinite plane of negative  charges?

如果我们添加一个等量、平行、无限的负电荷平面会怎样？

First  off, we know the electric field will be normal to and directed away from the infinite plane of  positive charges.

首先，我们知道电场垂直于正电荷的无限大平面，并远离正电荷的无限大平面。

Basically, we have an infinitely  large, infinitesimally thin, two-dimensional plane of positive charges which  are evenly spread out through the infinite plane.

基本上，我们有一个无限大、无限薄的二维正电荷平面，这些正电荷均匀分布在无限平面上。

Oh, and realize, the surface charge density  in the equation now refers to the magnitude of the surface charge density, which is the  same for both infinite planes of charges.

哦， 请注意， 等式中的表面电荷密度现在指的是表面电荷密度的大小，对于两个无限大的电荷平面来说都是相同的。