这个模型可以模拟在分子泵抽气通道内的气体分子速度与压力的分布。

The model can simulate the velocity and pressure distribution of molecular in the pumping channel.

youdao

简单地说，如果气体分子达到逃逸速度，它就能从一颗行星上“蒸发”。

Simply stated, a gas molecule can "evaporate" from a planet if it reaches a speed known as the escape velocity.

youdao

此外，由于气体的分子运动依赖于温度，在木星行星的低温下，即使是最轻的气体也不可能获得逃逸所需的速度。

Also, because the molecular motion of a gas depends on temperature, at the low temperatures of the Jovian planets even the lightest gases are unlikely to acquire the speed needed to escape.

youdao

There are no other molecules on that side of the wall. So there's an attractive force that makes the velocity within not quite as fast.

墙的另一边没有分子,因此吸引力,会降低球的速度。

麻省理工公开课 - 热力学与动力学课程节选