This is the permittivity of vacuum.

真空中的介电常数是。

Epsilon zero is the permittivity of vacuum.

0是真空中的介电常数。

There is the permittivity vacuum. It is all up there.

这儿还有真空中的介电常数，看，全在这里。

This means the permittivity of oil is greater that of air.

这就意味着油的介电系数大于空气的介电系数。

Effect of chirality and permittivity on the reflection and transmission was discussed.

讨论了不同情形下手征参数和介电常数对反射和透射特性的影响。