Oxygen freenitrogen pressure testing is now widely recommended.
现在广泛使用的是无氧氮气压力检测。
2
Within the nodules the bacteria convert freenitrogen to nitrates, which the host plant USES for its development.
根瘤内的固氮菌将游离氮转化为硝酸盐，被宿主植物在发育中利用。
3
The nitrogen Deoxo Vessel contains a fixed bed of free copper catalyst which removes oxygen from the nitrogen stream by oxidation of copper to copper oxides.