And so we are going to use that in order to construct some energy level diagrams.

我们就准备使用它,来建立一些能级图。

麻省理工公开课 - 固态化学导论课程节选

And I can find the orientation of the arrow You have the option of either working with the two components of A or with the arrow.

我也可以求得矢量的方向,你可以选择使用,A 的两个分量或者矢量图来计算

耶鲁公开课 - 基础物理课程节选