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

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。

麻省理工公开课 - 化学原理课程节选

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

In this demonstration, we're shown how users can manipulate objects on a 3D plane via the Z-axis by pulling the pen away from the display.

ENGADGET: Hands-on with wireless, ultrasonic stylus and touchless gestures at MWC (video)

Complex numbers, which have a real and an imaginary part added together, are the points on this plane that do not lie on either axis.

ECONOMIST: Beno?t Mandelbrot

And, as Euler's successor, Carl Friedrich Gauss, was to discover, if you plot real numbers on one axis of a graph and imaginary ones on the other, you create a plane that represents both sorts of numbers.

ECONOMIST: Beno?t Mandelbrot