Milton surveys the wealth of literary tradition before him, and he resists its allure without the help of any human guide.

弥尔顿在他之前就调查过文学传统的宝藏，他在没有人帮助的情况下抗拒了这一诱惑。

耶鲁公开课 - 弥尔顿课程节选

So you don't want to put in a negative energy, that's not going to help you out, you need to put in positive energy to get an electron out of the system. So that's why you'll find binding energies are always negative, and ionization energies are always going to be positive, or you could look at the equation and see it from there as well.

因为这对电离没有帮助,你需要一个正的能量,使得电子脱离这个系统,这就是为什么你会发现,结合能总是负的而电离能总是正的,或者你们看这个方程也可以发现这一点。

麻省理工公开课 - 化学原理课程节选