"What happens when you digitize these books and make them accessible on the net is that they get a lot more use,"

VOA: standard.2009.12.31

So, when we get really close together, granted, there is a net positive negative charge with a Coulombic force of attraction.

当它们真正离得很近时，假设有一个带正负电的电荷,带有库仑引力。

麻省理工公开课 - 固态化学导论课程节选