Economists have long considered government spending, especially on infrastructure, to be an effective tool for revitalizing a stagnating economy.

VOA: standard.2009.10.16

So we should be able to calculate a z effective for any atom that we want to talk about, as long as we know what that ionization energy is.

我们应该可以计算出任何一个,我们想要谈论的原子的有效电荷量，只要我们知道电离能是多少。

麻省理工公开课 - 化学原理课程节选