Nitrogen， which accounts for 78 per cent of the volume of air and exists in the form of a single substance， is a colourless， non-toxic and odourless inert gas. It has been widely used in food preservation， grain storage， metal heat treatment， petrochemical industry， aerospace technology， glass industry and many other fields.

1， the chemical nature of nitrogen is very stable， can replace the inert gas for welding metal protective gas.

2、Often some valuable and rare painting pages and scrolls are kept in the cylinder filled with nitrogen， so that the moths can be smothered in the nitrogen.

3、Filling it into the electric bulb can prevent the oxidation of tungsten filament and slow down the volatility of tungsten filament， and prolong the service life of the bulb.

4， the use of nitrogen to make food in a dormant and anoxic state， slow metabolism， you can get a good pest control， mould and deterioration effect， many areas of our country also apply nitrogen to save food， can also be used to save fruits and other agricultural by-products.

5， the treatment of tuberculosis "artificial pneumothorax"， is also the nitrogen into the chest cavity of tuberculosis patients， compression of the foci of the lung lobes， so that it can rest.

6、Use of liquid nitrogen to produce low temperature， to save the sperm of good breeding livestock， storage and transport around， and then used for artificial insemination after thawing.

7， the use of liquid nitrogen to cool the scalpel， it becomes "cold knife". Doctors use "cold knife" to do surgery， can reduce bleeding or no bleeding， after surgery， the patient can recover faster.

8， the use of liquid nitrogen for the treatment of skin diseases. This is because the gasification temperature of liquid nitrogen is -195.8 ℃， therefore， used to treat superficial skin diseases is often very easy to make the lesions of the skin necrosis， shedding.

9， nitrogen can also be used for professional racing， NOS nitrogen acceleration system， the effect is obvious， as long as you press and hold， the engine power immediately burst.

10， nitrogen is "the basis of life"， it is not only the raw material for the manufacture of chlorophyll crops， but also the raw material for the manufacture of proteins crops， according to statistics， within a year， to take more than 40 million tonnes of nitrogen from the soil.