The only thing that is different about these orbitals is their orientation in space.

这些轨道唯一的不同之处,是在空间的方向不同。

麻省理工公开课 - 化学原理课程节选

So it's along the bond axis and it's between a carbon s p 2 hybrid, and then the hydrogen is just a 1 s orbital that we're combining here.

所以它是沿着键轴方向的,而且这里是一个碳sp2杂化轨道，和一个氢的1s轨道的结合,在这里我们可以合并他们。

麻省理工公开课 - 化学原理课程节选

So we can also show them coming together this way, so now you're looking at it where you can see the p orbital, and maybe just see well one of the hydrogen atoms.

我们也可以看到它们从这个方向靠拢，现在你看的方向你可以看到p轨道，也许可以看到一个氢原子。

麻省理工公开课 - 化学原理课程节选

So this is a little bit trickier to look at and see what it means, but essentially we have two hybrid orbitals, which are shown in blue here, and then we have one p orbital that's left alone that's going up and down on the page.

看这个图肯能会觉得比较诡异，但本质上，骂我们有两个杂化轨道，这里用蓝色表示，还有剩下一个p轨道,在图中上下方向上。

麻省理工公开课 - 化学原理课程节选

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。

麻省理工公开课 - 化学原理课程节选

Specifically, it's always the z that forms the sigma orbital, and the reason is at least at a minimum for this class we always define the internuclear axis as the z axis, so this is always the z axis, so it's always going to be the 2 p z's that are coming together head-on.

特别的，z总是形成sigma轨道，这是因为至少在这个课里面,我们总是定义核间轴为z轴，所以这总是z轴，所以2pz轨道总是,朝一个方向出现。

麻省理工公开课 - 化学原理课程节选