So that is the bond axis it's just the axis between the two nuclei.

这就是键轴，它就是两个原子核之间的轴。

youdao

But keep in mind sigma orbitals have no nodal planes along the bond axis.

但记住sigma轨道沿着，键轴方向是没有节点的。

youdao

Pi orbitals are a molecular orbital that have a nodal plane through the bond axis.

轨道是沿着键轴,有节面的分子轨道。

youdao

So any time you have two atoms bonding, the bond axis is just the axis that they're bonding along.

任何时候如果你有两个原子成键，键轴就是它们成键的方向。

麻省理工公开课 - 化学原理课程节选

Remember this is our bond axis here, and you can see there is this area where the wave function is equal to zero all along that plane, that's a nodal plane.

记住这是我们的键轴，你可以看到在这些区域,波函数在这个面内全都是零，这是节点面。

麻省理工公开课 - 化学原理课程节选

So even though we see a nodal plane down the center, I just want to really point out that it's only when we have a nodal plane in the internuclear or the bond axis that we're calling that a pi orbital.

虽然在中间有个节面，我想要指出的是,只有节面在核间轴,或者键轴上时,我们才叫它π轨道。

麻省理工公开课 - 化学原理课程节选