In this study the whole work was divided into three aspects: study on pollution and its cleaning of hollow fiber membrane used in bubble free aeration;

本研究分为三个部分：对无泡曝气中空纤维膜的膜污染与清洗的研究；

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The relationship between hydraulic condition and bubble point of bubble free aeration, as well as the effects of hydraulic condition and air pressure on aeration were also discussed.

对中空纤维膜无泡曝气进行了试验研究，考察了中空纤维膜的高效曝气性能，探讨了水力条件与无泡曝气泡点的关系，以及水力条件和曝气压强对曝气效果的影响。

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The slush is compacted by an unknown mechanism, and solid, bubble-free ice is formed from water high in soluble organic substances.

半融雪通过一种未知的物理过程被压实，而固态、无气泡的冰是由富含可溶性有机物的水形成的。

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Keep the windows closed and the air-conditioning on, giving you an allergen free bubble.

FORBES: Six Brands to Consider and Six Suggestions of What to Do When February Flowers Bring March Allergies

Bubble messages are free to record, but you need to pay (at least airtime) to listen to them.

FORBES: Magazine Article

I've seen a couple of law review articles discussing the conflict between free speech rights and this electioneering bubble for individual voters.

NPR: Can Your Clothes Keep You From Voting On Election Day?