We know surface charge density  equals charge over area.

我们知道表面电荷密度等于电荷除以面积。

That means the charge inside the Gaussian cylinder equals the surface charge density times the  area of one end.

这意味着高斯圆柱内的电荷等于表面电荷密度乘以一端的面积。

On the right-hand side of the equation we can substitute the surface charge  density times the area of just one end.

在等式的右边，我们可以用表面电荷密度乘以一端的面积来代替。

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。

And we get that the magnitude of the electric  field which surrounds and is caused by an infinitely large, thin plane of charges  equals surface charge density divided by the quantity two times permittivity of free space.

我们发现，由无限大而薄的电荷平面包围并引起的电场强度等于表面电荷密度除以自由空间介电常数的两倍。