So if we add them all up, there should be no net charge on the molecule, if the molecule is neutral.

因此如果我们把它们都加起来，这个分子上应该没有净电荷，如果这个分子是中性的话。

麻省理工公开课 - 化学原理课程节选

Now the last thing is that because the neutron has no net charge, we can change neutron number.

现在，最后一件事是,因为中子没有净电子，我们可以改变中子数。

麻省理工公开课 - 固态化学导论课程节选

If I short the one-period bond it cancels out, so I've made no net purchase in 1925.

卖空一单位一年期债券则刚好抵消,所以我在1925年的净买入为零

耶鲁公开课 - 金融市场课程节选

This is providing work that's being used in here, but if you take the whole outside of the surroundings and this whole thing is the system, no net work, these things cancel each other, and yet heat's going up.

如果把外面的全部当成环境，把这里的全部当成系统,那么就没有净的功，它们相互抵消了，热量向上传输，会发生什么？

麻省理工公开课 - 热力学与动力学课程节选

So we can compare the two electron configurations, and we can actually think about what we figure out from them, we see that two are lowered in energy, two electrons are raised in energy, so we have no net gain or no net loss in energy for h e 2.

我们可以比较两种电子构型，我们可以考虑,我们发现这，两个电子能量变低，两个电子能量升高，所以在He2里没有净的能量得失。

麻省理工公开课 - 化学原理课程节选

So now that means if this is where the center of positive excess charge lies and on top of it is the center there is no displacement of the charge so there is no net dipole.

所以现在我们说,如果正电荷中心,就位于,那么还是在这里负电荷中心也在这里,所以没有空间偶极。

麻省理工公开课 - 固态化学导论课程节选

I am going to say if that electron is to stay in its orbit, that is to say it doesn't flee the atom, it doesn't collapse under the nucleus then the sum of the forces on the electron must be zero No net force. And so that will be the sum of a dynamic force plus an electrostatic.

如果电子会保持在它的轨道上运行,既不脱离原子的话，它就不会由于原子核对它的吸引力而被瓦解掉,电子所受的合力一定为零,由于没有合力,所以电子所受力为动态力和静电力的总和。

麻省理工公开课 - 固态化学导论课程节选