2017网络广告市场规模:人工固氮的英文解释,及研究历史

来源:百度文库 编辑:中科新闻网 时间:2024/04/26 12:57:27
研究历史,,相关科学家,越详细越好~谢谢

英文我想应该是artificial nitrogen fixation, 或者human-fixed nitrogen,前者意思是人工固氮,后者是人工固定下来的氮,呵呵,听起来好像比较别扭。

相关的文章请参看以下:

1、人工固氮

工业上通常用H2和N2 在催化剂、高温、高压下合成氨

最近,两位希腊化学家,位于Thessaloniki的阿里斯多德大学的George Marnellos和MichaelStoukides发明了一种合成氨的新方法(Science,2Oct.1998,P98)。在常压下,令氢与用氦稀释的氮分别通入一加热到570℃的以锶-铈-钇-钙钛矿多孔陶瓷(SCY)为固体电解质的电解池中,用覆盖在固体电解质内外表面的多孔钯多晶薄膜的催化,转化为氨,转化率达到78%;对比:几近一个世纪的哈伯法合成氨工艺通常转化率为10至15%!他们用在线气相色谱检测进出电解池的气体,用HCl吸收氨引起的pH变化估算氨的产率,证实提高氮的分压对提高转化率无效;升高电流和温度虽提高质子在SCY中的传递速度却因SCY导电率受温度限制,升温反而加速氨的分解。

2、天然固氮

闪电能使空气里的氮气转化为一氧化氮,一次闪电能生成80~1500kg的一氧化氮。这也是一种自然固氮。自然固氮远远满足不了农业生产的需求。

豆科植物中寄生有根瘤菌,它含有氮酶,能使空气里的氮气转化为氨,再进一步转化为氮的化合物。固氮酶的作用可以简述如下:

除豆科植物的根瘤菌外,还有牧草和其他禾科作物根部的固氮螺旋杆菌、一些原核低等植物——固氮蓝藻、自生固氮菌体内都含有固氮酶,这些酶有固氮作用。这一类属自然固氮的生物固氮。

Nitrogen fixation is the process by which nitrogen is taken from its relatively inert molecular form (N2) in the atmosphere and converted into nitrogen compounds useful for other chemical processes (such as, notably, ammonia, nitrate and nitrogen dioxide).

Nitrogen fixation is performed naturally by a number of different prokaryotes, including bacteria, and actinobacteria certain types of anaerobic bacteria. Many higher plants, and some animals (termites), have formed associations with these microorganisms.

Biological Nitrogen Fixation
Biological Nitrogen Fixation (BNF) occurs when atmospheric nitrogen is converted to ammonia by a bacterial enzyme called nitrogenase. Microorganisms that fix nitrogen are called diazotrophs. The formula for BNF is:

N2 + 8H+ + 8e− + 16 ATP → 2NH3 + H2 + 16ADP + 16 Pi
Although ammonia (NH3) is the direct product of this reaction, it is quickly ionized to ammonium (NH4+). In free-living diazotrophs, the nitrogenase-generated ammonium is assimilated into glutamate through the glutamine synthetase/glutamate synthase pathway. Biological nitrogen fixation was discovered by the Dutch microbiologist Martinus Beijerinck.

Leguminous nitrogen-fixing plants
The best-known are legumes (such as clover, beans, alfalfa and peanuts,) which contain symbiotic bacteria called rhizobia within nodules in their root systems, producing nitrogen compounds that help the plant to grow and compete with other plants. When the plant dies, the nitrogen helps to fertilize the soil. The great majority of legumes have this association, but a few genera (e.g., Styphnolobium) do not.

Non-leguminous nitrogen fixing plants
Plants from many other families have similar associations, including:

Lobaria lichen and some other lichens
Mosquito fern (Azolla species)
Cycads
Gunnera
Alder (Alnus species)
Ceanothus (Ceanothus species)
Wax myrtle (Myrica species)
Mountain-mahogany (Cercocarpus species)
Bitterbrush (Purshia tridentata)
Buffalo berry (Shepherdia argentea)
Ironwood (Casuarina species), Sheoak (Allocasuarina species), and other genera in the Casuarinaceae

Chemical nitrogen fixation
Nitrogen can also be artificially fixed for use in fertilizer, explosives, or in other products. The most popular method is by the Haber process. Artificial fertilizer production has achieved such scale that it is now the largest source of fixed nitrogen in the Earth's ecosystem.