基本释义 n. 氮

常考释义 n. 氮

n. 氮(化学元素)【化】


1. But nitrogen is an unstable element.(TPO31-L4)


2. So the transfer of this nitrogen to the forest is important. (TPO52-L2)


3. Plants absorb this nitrogen which they need to grow. (TPO52-L2)


4. Now, salmon contain nitrogen.  (TPO52-L2)


n. 氮


1. The growth of organisms is dependent on the availability of nutrients, none of which is more important than nitrogen. (TPO53-P2)


2. Although there is an abundant supply of nitrogen in Earth’s atmosphere, it cannot be absorbed by plants unless it is “fixed,” or combined chemically with other elements to form nitrogen compounds. (TPO53-P2)


3. Nitrogen-fixing bacteria help tropical rain forest plants cope with the poor soils there by supplying them with needed nitrogen. (TPO53-P2)


4. Nitrogen fixation by free-living bacteria in tropical soils is also beneficial.(TPO53-P2)


5. But before we go into that, let’s look at the role of nitrogen fertilizer in modern farming. (TPO53-L2)


6. But these legumes also enriched the soil by converting nitrogen in the atmosphere into nitrates, a form of nitrogen that crops like wheat or corn could use as nutrient. (TPO53-L2)


7. They stored much of the surplus nitrogen during the time of the year when the runoff tended to be the greatest.(TPO53-L2)


8. And the excess nitrogen once trapped by these cover crops either washed away in the next big rain or went down into the groundwater and either way eventually ended up in the streams and the bay, and that as we said means more algae in the water and less oxygen for the fish and other aquatic life to breathe.(TPO53-L2)


9. Other kinds like rye and barley that hold the nitrogen and keep it from washing out of the soil during the months when that most likely to occur. (TPO53-L2)


10. The roots of these trees can absorb the excess nitrogen in the runoff before it reaches the streams. (TPO53-L2)


11. So the transfer of this nitrogen to the forest is important. (TPO52-L2)


12. The art of farming was careful soil selection, that is, knowing which soils were light and easily cultivable, could be readily turned with small hoes, and would maintain their fertility over several years' planting, for cereal crops rapidly remove nitrogen and other nutrients from the soil. (TPO52-P3)


13. The bacteria that legumes host within their root nodules (small swellings on the root) change nitrogen gas from the atmosphere into nitrogen compounds that plants are able to metabolize, a process, known as nitrogen fixation, that makes the soil more fertile.(TPO36-P1)


14. Two additional kinds of evidence support the hypothesis that petroleum is a product of the decomposition of organic matter: oil possesses optical properties known only in hydrocarbons derived from organic matter, and oil contains nitrogen and certain compounds believed to originate only in living matter. (TPO43-P2)


15. You see, horse manure, horse waste is rich in phosphorus and also nitrogen compared to normal soil.(TPO31-L4)


16. The soil from the Botai settlement sites was found to have high concentrations of phosphorus and low nitrogen concentrations, which is important since it suggests that what we’ve got is really old, not something added to the soil more recently.(TPO31-L4)


17. Wait. So if horses have been there recently, there’d still be lots of nitrogen in the soil.(TPO31-L4)


18. For example, how much nitrogen or magnesium there’s in the soil in one spot.(TPO29-L1)


19. The major difference is that Allende is depleted in the most volatile elements, like hydrogen, carbon, oxygen, nitrogen, and the noble gases, relative to the Sun. These are the elements that tend to form gases even at very low temperatures. (TPO22-P3)


20. When photons and light waves hit objects in our atmosphere, water droplets, oxygen and nitrogen molecules, dust particles and so on, (TPO19-L2)


21. A century earlier, Henry Cavendish had noted the existence of a residual gas when oxygen and nitrogen are removed from air, but its importance had not been realized. (TPO16-P2)


22. The three most important nutrient cycles are the nitrogen cycle, the carbon cycle and the one we are going to talk about today, the Phosphorus cycle. (TPO10-L3)


23. What about, well, you said that the nitrogen cycle is also an important nutrient cycle. (TPO10-L3)


24. And there is a lot of nitrogen in the atmosphere, so I was wondering, is there a lot of Phosphorus in the atmosphere, too? (TPO10-L3)


25. However, there’s just not a substantial amount of it there, like there is with nitrogen. (TPO10-L3)

90/5000 然而,那里的数量并不大,就像氮气一样。

26. These microbes enable the soil to have more nitrogen, which plants need to live and they remain quite active during the winter. (TPO9-L2)


27. Even nitrogen, which is a gas in its elemental state, is normally absorbed from the soil as nitrate ions. (TPO5-P1)


28. Soils are most commonly deficient in nitrogen and phosphorus. (TPO5-P1)