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- Practically all industriall important cationics are fatty nitrogen compounds and many are quaternary nitrogen compounds. 实际上工业中所有的重要阳离子表活剂都是含氮化合物，其中许多是季铵盐类化合物。
- Air consists chiefly of nitrogen. 空气主要由氮气组成。
- Nitrogen forms most of the Earth's air. 地球上空气的大部分成分是氮气。
- quaternary nitrogen 季氮
- The lamp is full of gaseous nitrogen. 灯里充满了气体氮。
- Nitrogen forms about 78% of the earth's atmosphere. 氮约占地球大气的百分之七十八。
- The Quaternary sediments are largely undeformed. 第四纪的沉积物大部分未变形。
- Cationics are usually quaternary ammomium salts. 阳离子表面活性剂通常为季铵盐类。
- Design of quaternary Schmitt circuits. 四值施密特电路设计。
- IS THERE REALLY QUATERNARY GLACIATION ON LUSHAN? 庐山真的有第四纪冰川吗?
- Will you sunder nitrogen from air? 你能从空气中把氮气分离出来吗?
- Nitrogen is the most commonly used gas. 氮气是最常用的气体。
- Sample gas tubes are flushed with nitrogen. 采气管得用氮气吹扫。
- The main reservoir of nitrogen is the atmosphere. 氮的主要蓄存库是大气层。
- What is the percentage of nitrogen in air? 空气中所含的氮的比例是多少?
- Fast neutrons are also captured by nitrogen. 快中子也可以被氮吸收。
- Nitrogen forms four-fifths of the atmosphere. 氮气占空气的五分之四。
- Nitrogen forms about four-fifths of the atmosphere. 氮约佔大气的五分之四。
- The cover rocks are marine mudstone from Pliocene to Quaternary. 储层发育有砂岩、灰岩（礁灰岩）、基岩等。
- What is the content of the crude nitrogen. 污氮的含氧量是多少?
