First, we know that the planets all orbit close to the earth's orbital plane, the ecliptic.

首先，我们知道所有行星的轨道都很靠近地球的轨道平面——黄道面。

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The optimization performance index is to maximize the orbital plane change, and the optimal lift and bank control law are obtained.

以目标轨道面倾角最大为优化性能指标，获得了升力和滚转角的最优控制规律。

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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。

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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

The reason that I wanted to point out this nodal plane here is because this is why it is called a pi orbital.

我指出这个节面的原因是因为,它就是为什么这个叫做π轨道的原因。

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

In its Wednesday review, Russian officials said they expect to decide whether to delay the launch by 10 hours to put it in the same orbital plane as the new station.

CNN: Russia reluctant to let Mir die

Sharing the same orbital plane would make is much easier to transfer equipment from Mir, although NASA, the leading partner in the new station, had not planned to use Mir transplants.

CNN: Russia reluctant to let Mir die

The agency has already spent billions of dollars on the National Aerospace Plane, the X-33, X-34, X-37, X-38 and the Orbital Space Plane.

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