/2 You can have it equal to plus 1/2, and that's what we call spin up, 1/2 or you can have it equal to minus 1/2, which is what we call spin down.

它可能会等于，我们叫它自选朝上，或者它等于负，我们叫它自旋朝下。

麻省理工公开课 - 化学原理课程节选

So you can see, if it's spinning on its own axis in this direction we'd call it spin up, where as this way it would be what we call spin down.

你们可以看到，如果它绕自己的轴朝这个方向转,我们就说它是自旋朝上，这个方向我们叫它自旋朝下。

麻省理工公开课 - 化学原理课程节选

Both of these are spinning but they are spinning in the same level.

它们都是在自旋,但是它们都在相同水平上自旋。

麻省理工公开课 - 固态化学导论课程节选