The first is this the z effective, or how much charge is actually in the nucleus that's felt, Z or the I guess we would say the z, how much the charge is on the nucleus that holds it close together.

第一个是有效核电量，或者说实际感受到的核电荷量，又或者我想我可以说就是，使它们保持在一起的,原子核的电荷量。

麻省理工公开课 - 化学原理课程节选

And we know that it's electron density between the nuclei that holds two atoms together in a bond.

我们知道是两个原子核之间的,电子密度保持两个原子在一起成键的。

麻省理工公开课 - 化学原理课程节选

That cells that form tissues often have junctions that hold them together so that they don't fall apart and they exist as a solid piece of tissue.

组织细胞通常通过,细胞连接而联系在一起,所以它们不会分散开来,而保持坚固的组织形态

耶鲁公开课 - 生物医学工程探索课程节选