And just to give you a sense, if you do a cross-cut of this, you cannot show it from this angle, but it should really be sort of a dumbbell shape with the nodal plane in between the two nuclei.

告诉你们这些就是给你们点概念，假如你们把他横切切开，不能从角度上展示，但它还是会保留几分哑铃的形态,以及在两核之间的节面。

麻省理工公开课 - 固态化学导论课程节选

Another way to represent a point in a plane is I've got a radius and I've got an angle from the x-axis, right, and that's a standard thing you might do.

平面上面的点的方法,也就是极坐标,上面那种方法其实是，如果你们喜欢我这么说的话,笛卡尔坐标表示法。

麻省理工公开课 - 计算机科学及编程导论课程节选