Nitrogenfixed by legume root nodules accounts for 40% of total biological nitrogen fixation.
豆科植物的根瘤固氮占生物固氮总量的40%。
2
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.
氮气脱氧罐中装有一个游离铜催化剂的固定床，通过将铜氧化成氧化铜把氧气从氮气中脱除。
3
Results show that four major influence factors of pulverized coals NO static emission amount are carbon content, fixed carbon content, nitrogen content and ash content respectively.