重水之所以重是因为水中氢的重量是普通氢的两倍（它的原子核中有一个质子和一个中子，而不仅仅是一个质子）。
Heavy water is heavy because the hydrogen in it weighs twice as much as ordinary hydrogen (it has a proton and a neutron in its nucleus, instead of just a proton).
说清楚，这是原子氢的1s原子轨道。
This is the 1s. And, just to be clear, this is the 1s atomic orbital in atomic hydrogen.
是氢的键更短，还是氮与氮的三键更短？
Is a hydrogen bond shorter, or is a nitrogen-nitrogen triple bond going to be shorter?
应该是氢的还是氮的？对，应该是氮的。
Is it going to be hydrogen or nitrogen? Yup, it's going to be nitrogen.
氢的优势是其结构非常简单：一个电子环绕一个质子。
The advantage of hydrogen is its unrivalled simplicity: one electron circles a single proton.
这类白矮星中有着重元素痕迹者，大多也会有氢的痕迹。
Among this group, most of those with traces of heavy elements also have traces of hydrogen.
到那时纯镁可用作燃料(其能量密度大约是氢的十倍)。
The pure magnesium can then be used as a fuel (its energy density is about ten times that of hydrogen).
最好的核聚变材料有两种，即氢的同位素——氘和氚。
The best fuels for fusion are two types, or isotopes, of hydrogen - deuterium and tritium.
其中放置了一个更微小的氘(氢的一种同位素)燃料丸。
It contains a tiny pellet of fuel made from an isotope of hydrogen called deuterium.
而分解出氢的效率以重量计算可比其它太阳能热制程的效率高出一个数量级。
The gravimetric hydrogen production rate exceeds that of other solar-driven thermochemical processes by more than an order of magnitude.
一群强大的巨型恒星点燃蔷薇星云的中心，来自电离氢的红光使其绚丽夺目。
The center of the Rosette Nebula, which glows with the red light of ionized hyrdorgen, is fueled by a central cluster of powerful giant stars.
氘是氢的同位素，在地球上的海洋中广泛存在，其质量较重，很难逃离金星大气。
Deuterium is a heavier form of hydrogen that is common in Earth's oceans and that would have too much mass to escape Venus' atmosphere.
储存氢的另一方法是在燃料箱中放点东西，增加氢分子能够附着的内表面总面积。
Another way to store hydrogen is to put something inside the tank which increases the total internal surface area to which the molecules of the gas can cling.
研究人员希望能找到一个类似的基于生物的系统来执行该进程的另一半，氢的生产。
The researchers hope to find a similar biologically based system to perform the other half of the process, the production of hydrogen.
他们说：这可能造成“提坦”卫星上乙炔的缺失和靠近卫星表面氢的耗尽，那里是微生物生活之处。
This would result in a lack of acetylene on Titan and a depletion of hydrogen close to the moon's surface, where the microbes would live, they said.
虽然廉价的燃料电池及其他转换氢发电的技术已经相当先进，但现在还没有廉价的大量生产氢的方法。
Although cheaper fuel cells and other technology needed to convert hydrogen to power are fairly advanced, there is currently no way to cheaply generate the large quantities of hydrogen needed.
科学家用到了一种叫离子显微镜的仪器，来比较月球岩石上氢的含量与重氢含量（重氢比普通氢多带有一个中子）。
The researchers used what’s called an ion microscope to compare the amount of normal hydrogen in the moon rocks to the amount of the hydrogen isotope deuterium, which carries an extra neutron.
为了使蓝杆菌51142更有效的工作，伦兹建议对其进行基因改造，使其包含更有效的氢化酶，以减少氢的损失。
51142 work better, Lenz suggests genetically modifying the bacterium to contain a more efficient hydrogenase enzyme, so less hydrogen is lost.
其它日本汽车制造商已经开始着手制造燃料电池汽车，这种汽车通过氧和氢的化学反应来发电，而这种化学反应的副产品只有水。
Other Japanese automakers have been working to create fuel cell cars, which produce electricity through a chemical reaction between hydrogen and oxygen, with water the only by-product.
无论如何，μ介子氢的兰姆位移更加依赖于质子的半径，因为相对电子更加重的μ介子靠近或者时不时进入质子本身的时间也更多。
However, in muonic hydrogen the Lamb shift is much more dependent on the proton radius because the much heavier muon spends more time very near to – and often within – the proton itself.
千万年以来，人类的主要燃料是木头，燃烧木头的过程中，碳和氢的比率是10比1。相比较而言，煤在燃烧过程中这个比率是2比1，而石油的比率则是1比2。
Humanity's main fuel for eons was wood, which has a carbon-to-hydrogen ratio of 10 to 1 when burned; by comparison, that ratio is 2 to 1 for coal and 1 to 2 for oil.
燃料电池是一种利用某种燃料（举例：氢）和氧化剂通过电化学过程产生电能的装置。
A fuel cell is a device that uses a source of fuel, such as hydrogen, and an oxidant to create electricity from an electrochemical process.
宝马氢能7系虽然暂不出售，但它是推动氢能替代燃料的里程碑。
The BMW hydrogen 7 is not for sale, but is considered to be a milestone in bringing forward hydrogen as the sustainable fuel for individual transportation.
最终情况很有可能是——氢燃料电池取代现在无所不在的内燃机。
Eventually, it is hoped, fuel cells running on hydrogen will take the place of the ubiquitous internal combustion engine.
研制这款Riversimple城市汽车的公司宣布，该车证明了氢动力汽车技术业已成熟，可以量产汽车，而无需再等10年。
The company behind the Riversimple urban car claim the new model proves hydrogen automotive technology is ready for roll-out now rather than in 10 years' time.
此外，由于有太阳能电源以及氢能源电池组，它完全能够自给自足而不需要任何形式的地面电能补给。
Also, it's totally self-sustained, thanks to a solar energy and hydrogen fuel cell combo, and it doesn't require any kind of input from the ground.
当作为燃料的氢消失，且聚变过程减缓时，重力就导致恒星向内坍缩。
When the hydrogen used as fuel vanishes, and fusion slows, gravity causes the star to collapse in on itself.
恒星聚缩时甚至继续升温，这个过程燃尽了残存的氢，并导致恒星外层向外膨胀。
As the star condenses and compacts it heats up even further, burning the last of its hydrogen and causing the star's outer layers to expand outward.
从理论上讲，氢燃料电池驱动的汽车是无污染的，但由于氢难以廉价、大量地生产，这种汽车在普及方面打了折扣。
Vehicles powered by hydrogen fuel cells are, in theory, pollution-free but their popularity has been compromised by the difficulty of generating hydrogen cheaply and plentifully.
从理论上讲，氢燃料电池驱动的汽车是无污染的，但由于氢难以廉价、大量地生产，这种汽车在普及方面打了折扣。
Vehicles powered by hydrogen fuel cells are, in theory, pollution-free but their popularity has been compromised by the difficulty of generating hydrogen cheaply and plentifully.
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