Aravind Eye Care System received the Conrad N.Hilton Humanitarian Prize.

VOA: special.2010.04.27

All the energies are negative because it is a bound system. I start up here with n equals one.

所有能量级都是负数，因为它是一个束缚系统,在这里我从n等于1讲起。

麻省理工公开课 - 固态化学导论课程节选

This should make sense to you, because they don't, in fact, want to gain another electron, because that would mean that electron would have to go into a new value of n, a new shell, and that's really going to increase the energy of the system.

这对大家来说应该容易理解，因为它们实际上不想得到另一个电子，因为这意味着这个电子不得不,到一个新的，n，值更大的壳层上去，这将会增加系统的能量。

麻省理工公开课 - 化学原理课程节选