Plants are the main source of atmospheric oxygen.
大气中的氧主要是由植物产生的。
Usually, atmospheric oxygen content is about 20%, carbon dioxide containing about 0.03%.
通常，大气中的氧气含量约为20%，二氧化碳约含0.03%。
As atmospheric oxygen levels fall, less oxygen will dissolve in seawater, depleting levels slightly.
由于大气中氧气含量的减少，较少的氧气溶于海水，使得海水中的含氧量轻微的减少。
As far as we can tell Earth's atmospheric oxygen has remained at about 20 percent for hundreds of millions of years.
据我们所知，地球大气中20%左右的氧含量已保持了亿万年之久。
They have a particular interest in the jumps in the level of atmospheric oxygen seen about 2.4 billion years ago and 600m years ago.
在24亿年前和60000万前年大气中氧的水平的变化方面，他们有一个特殊的兴趣。
The cure-inhibition effect of the atmospheric oxygen usually causes the surface stick of the cold-cured unsaturated polyester resin.
由于空气中氧的阻聚效应，而经常引起室温固化不饱和聚酯树脂表面发粘。
It is a car that stores hydrogen on board, and, mixing the hydrogen and atmospheric oxygen in the fuel cell stack, creates electricity, said Mittleman.
这种汽车可以将氢储存在车上，然后将氢和大气中的氧气在电池箱中混合，产生电力。
In the older rocks below these glacial deposits are detrital uraninite and pyrite two minerals considered evidence for very low levels of atmospheric oxygen.
这些冰河沉积物下方的较老岩层，是沥青铀矿与黄铁矿碎屑；这两种矿物被认定为大气中氧气极为稀少的证据。
The dry conditions and lack of atmospheric oxygen mean that the stuff has not rusted, says Geoffrey Landis of NASA's Glenn Research Center in Cleveland, Ohio.
俄亥俄州克里夫兰市美国国家航空航天局格伦研究中心的杰弗里．兰迪斯说，火星环境干燥，而且大气中缺乏氧气，这意味着那里的铁没有生锈。
In the history of biological and geochemical evolution, oxygen rise is a critical event. Some crucial evolutionary steps were linked to the elevated atmospheric oxygen.
在生物和地球化学进化史上，氧气的出现是一个关键的历史事件，代谢方式的改变直接促进了高等生命的进化。
Remember the 1980s, when it seemed the Amazon rain forest wasn't long for this world — and that humanity was threatened as atmospheric oxygen levels correspondingly declined?
记得上世纪80年代，亚马逊雨林似乎很快就要在世上消亡了，但难道这会导致大气中的氧含量相应下降，进而使人类受到威胁？
Once photosynthesis had raised atmospheric oxygen levels high enough, the ozone layer formed, meaning that it was then possible for living things to venture onto the land.
一旦光合作用上升了大气氧气成水平足够高，臭氧层被形成，意味，它是然后可能为生存事冒险土地。
If life exists, scientists expect the planet's rays to be embedded with tell-tale chemical fingerprints of atmospheric molecules, such as oxygen and methane.
如果生命存在，科学家们希望这个行星上的光线能够嵌入大气层分子的化学指纹位移指示器，像氧气、甲烷一类的气体。
To get a feel for what this would mean, bear in mind that the amount of oxygen in a given volume of air changes with atmospheric pressure, and the local pressure changes with the weather.
要了解这将意味着什么？给定体积的空气中的含氧量是随着大气压变化而变化的，而当地的气压又是随天气变化的。
With low-oxygen waters currently producing abouthalf of the ocean's net nitrous oxide, we could see an additionalsignificant atmospheric increase if these 'dead zones' continue toexpand.
目前低氧水域产生的一氧化二氮占海洋一氧化二氮净产出的一半，如果这些“死水区”继续扩大，我们将看到大气中的一氧化二氮会有更加显著的增加。”
Atmospheric carbon dioxide has been orders of magnitude above current levels and oxygen has ranged down to near zero.
大气二氧化碳一直数量级超过目前水平和氧气的交易区下降到接近零。
Next is what they call a bladder of oxygen that's an inflatable sac, filled with oxygen, to simulate atmospheric pressure.
下一个我们讲的是氧气气囊是一种可充气的气囊，为了模仿大气压力。
An oxygen chamber is designed to allow someone to breathe in 100% oxygen instead of the low concentration humans breathe in regular atmospheric conditions.
氧气舱的设计意图，是为了人能够在百分之百是氧气的环境中呼吸，而非在常规大气条件下呼吸。
Sulfur isotope studies demonstrate that sulfur was derived from the mantle, and oxygen isotope analyses reveal that the fluid of the deposit was a mixed source of magmatic water and atmospheric water.
同位素研究表明，矿层中硫来源于地幔，而氧同位素则显示其成矿过程有大气降水的参与。
The method of liquid oxygen oxidation of chlorotoluene mixture was choosen to synthesize chlorobenzoic acids, and the reactions were carried out under atmospheric pressure.
本文在研究氯甲苯混合氧化合成氯苯甲酸工艺时，采用氧气液相催化氧化法，反应压力为常压。
Inhalation of pure oxygen at atmospheric pressure or less can cause pulmonary irritation and edema after 24 hours.
在大气压或更低气压下吸入纯氧，24小时后会导致肺刺激和水肿。
Some of them, such as nitrogen, oxygen, argon, neon, and so on, may be regarded as permanent atmospheric components that remain in fixed proportions to the total gas volume.
其中一些气体，如，氮，氧，氩，氖等，作为空气的永久组成成分，总是以固定的比例存在于大气中。
Methods This device accesses oxygen storage devices in the original pipeline which absorbs oxygen in the atmospheric with the second grade pressure reducer.
目的：对经二级减压器吸氧的管路进行改进，以降低吸氧阻力。
In this thesis, the heterogeneous reactions of SO_2 with oxides, atmospheric particles and mixtures were studied in the presence of oxygen.
大气颗粒物与大气化学成分的多相反应这一课题属于前沿课题。
Qingzang Railway is in the district of high elevation and low atmospheric pressure. The passenger cars running in the district should be supplied with oxygen to ensure safety of passengers.
青藏铁路处于高海拔、低气压地区，在此区间运行的客车需供氧以保证旅客的安全。
Qingzang Railway is in the district of high elevation and low atmospheric pressure. The passenger cars running in the district should be supplied with oxygen to ensure safety of passengers.
青藏铁路处于高海拔、低气压地区，在此区间运行的客车需供氧以保证旅客的安全。
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