First of all, it's clear from the Pythagoras' theorem that a is the square root of ^2 + ^2.

首先,根据毕达哥拉斯定理,勾股定理在西方被称为"毕达哥拉斯定理"

耶鲁公开课 - 基础物理课程节选

So if we have total +2 and complete shielding -1 where that can actually negate a full positive charge, because remember our nucleus is plus 2, +1 one of the electrons is minus 1, so if it totally blocks it, all we would have left from the nucleus is an effective charge of plus 1.

抵消一个完全的正电荷,因为记住我们的原子核是,其中一个电子是,所以如果它完全挡住了它，我们从原子核中留下的，全部有效电荷就是，所以，在我们的第一个例子中,我们的第一种极端情况。

麻省理工公开课 - 化学原理课程节选

As reported contemporaneously in 2000,the number was -3.1% but if you look at the number reported for 2005, because bad records had disappeared and good records had been added, all of a sudden the average experience for that year went up to +1.2%.

000年期的公告中这个数字为负3.1%,但是如果你去查2005年公告的数字,坏记录已经调整而消失,有利的投资记录被加入,转瞬之间,年平均收益升至1.2%

耶鲁公开课 - 金融市场课程节选