That could be because the collision that made the moon in the first place was so hot that volatile elements like hydrogen, a key component of H2O, largely burned away.

这可能是因为月球形成过程中，撞击产生的热能使挥发性氢元素——水的重要组成成分——大量流失。

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This work focus on the calculation of the cross-section of the electron-hydrogen like Uranium collision. The interference effect of DR and RR was investigated near the resonant energy.

本工作计算了电子与类氢的铀离子碰撞截面随能量的变化，研究了在共振能量附近，DR和RR过程的干涉。

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But the collision probability of the spray particle against the cylinder wall will increase when the hydrogen concentration in the air exceeds a certain limit.

但氢气浓度超过一定值后则会增大柴油液滴碰壁的概率。

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If the vehicle in the unfortunate circumstances of a collision, has to be able to maintain the security of the hydrogen which means more mass, which means a lot of the efficiency is being squandered What's the environmental impact of hydrogen production?

如果车辆,在碰撞中发生了不幸，要仍然能够保持氢气的安全性的话,意味着需要更多的质量，也就是说大部分效率被浪费了,制氢对环境有什么影响呢？

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