By tracking this ratio over time, he can determine how long gas has taken to reach the surface and gain clues to the chemical, thermal, and mechanical state of the rocks the gas is passing through.

通过追踪该比率随时间的变化，他可以确定氡气到达地表需要花费多长时间，同时获得气体所通过的岩石的化学、热力学和机械状态。

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This frothing is achieved by passing the gas through side holes in the tube.

通过向管子侧孔通气就可以产生泡沫。

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Regeneration of the deactivated catalyst was conducted by passing carrier gas at given temperature through the catalyst, resulting in the recovery of its initial activity.

同时进行了催化剂的再生研究，在载气下于一定温度将催化剂热再生，基本上可恢复催化剂的活性。

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Post-combustion, CO2 is removed from flue gas by passing it through a liquid amine which dissolves the CO2.

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This can be done by heating the gas (a thermal plasma) or passing an electric current through it (a non-thermal plasma).

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