它们的目标是清理主系统的水，提供分离的停止，冷却的功能，水化学，装料及容量控制，补充水。
They are aimed at either cleaning the water in the primary system, providing separate shutdown cooling functions, water chemistry, charging and volume control, makeup water.
长期以来，研究人员已经了解到：温室气体通过对同温层的冷却作用，可以放慢破坏臭氧层的化学反应速度，因此也许会有助于臭氧层的恢复。
Researchers have long known that greenhouse gases might help the layer recover by cooling the stratosphere, which slows the rates of chemical reactions that destroy ozone.
生物学处理过程的另一个好处是它无需加热或冷却，而且无有毒化学品。
Another advantage of the biological system is that it requires no heating or cooling, and no toxic chemicals.
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