If you travel by bus in Sao Paulo,Brazil these days your vehicle may be powered by hydrogen fuel cells.
VOA: special.2009.09.07
I'm going to write it like this three moles of hydrogen which is a gas one bar 100 degrees Celsius.
我会写成这样:,三摩尔氢分子,气体,1巴,100摄氏度。
Let's look at the energetics of one of those electrons crashing into a hydrogen atom inside the gas tube.
我们一起来考察一下,其中的一个电子的能量,在阴极射线管中,撞击到氢原子上。
It contains forms of hydrogen and oxygen that can mark, or label, these elements within body water.
VOA: special.2011.07.27
HBr So for example, if I want to look at HBr there's a simple case, right, hydrogen bromine.
如果我想研究,这是个简单的例子,溴化氢。
One shows the remains of a dying star four thousand light years away which has thrown off a cloud of glowing hydrogen gas.
VOA: special.2009.09.30
So what we can actually directly compare is the dissociation energy or the bond strength of nitrogen versus hydrogen.
因此实际上我们可以直接进行比较,对氮分子与氢分子的离解能,或键的强度。
The bus uses a hybrid system that combines the hydrogen fuel cells with high power batteries.
VOA: special.2009.09.07
There's not actually chemical covalent bonds that are formed but it's a non-covalent interaction, usually dominated by hydrogen bonding.
所以配体和受体之间不生成共价键,这是一种非共价化合反应,它们通常以氢键相联
But not everyone sees the hydrogen fuel cell bus as the hope of the future.
VOA: special.2009.09.07
And, if we wanted to try to fit, say, hydrogen, into this scheme that we have, we have to do what?
如果我们想要让他们符合我们的原理比如氢气,我们需要怎样?
Mister Zundt says a hydrogen bus will last an average of twenty years, while a diesel bus can be used for five to eight years.
VOA: special.2009.09.07
But it is interesting. Let's just, for an order of magnitude say what happens for ground state electron in atomic hydrogen?
但行星模型其实挺有趣的,按照重要的先后顺序,我们来猜想一下,氢原子中的基态电子会发生些什么?
The city's urban transportation system recently launched the first of up to five hydrogen buses.
VOA: special.2009.09.07
And, even Cavendish, one of the things that he observed was that hydrogen could be combusted to produce water vapor.
甚至卡文迪许都观察到了,氢气燃烧,会产生水蒸气。
The action of oil and natural gas created hydrogen sulfide in the limestone.
VOA: special.2009.12.07
If we take hydrogen peroxide in the liquid state, it can break down to form water and oxygen.
如果我们有一些液态的过氧化氢,它会分解成水和氧气。
He regretted that work was being done to develop the hydrogen bomb.
VOA: special.2009.06.14
So in addition to having these two carbon bonds, we actually also have four carbon hydrogen bonds in addition to our carbon-carbon bonds.
在这碳碳之间的键以外,我们还有四个碳氢键,除了我们的碳碳键外。
Hydroxyl is the combination of one hydrogen atom and one oxygen atom.
VOA: special.2009.09.30
It is a double column, You can see, it starts with hydrogen and goes to mercury in ascending order of atomic mass.
双纵栏,你们看到,从氢开始,然后到水银,按原子质量的升序排列。
The project hopes to export hydrogen fuel cell buses in the future.
VOA: special.2009.09.07
In contrast, the dissociation energy of a bond for hydrogen, and molecular hydrogen is everywhere around us, we see 432 kilojoules per mole.
相反,氢分子在我们周围到处都是,一个氢分子的离解能,是432千焦每摩尔。
The hydrogen sulfide reacted with oxygen in rainwater moving through the rock.
VOA: special.2011.04.11
So if I tell you that the energy for single hydrogen atom is negative 13 12 kilojoules per mole.
如果我告诉大家单个氢原子的能量,是负的,1312,千焦每摩尔。
Water is made of one oxygen atom and two hydrogen atoms.
VOA: special.2009.09.30
I mean, you would expect that the group one, absent hydrogen, would be the ones that would have the least.
我想,你们可能认为第一主族,没有氢,而氢应该是最小的。
They both worried about the possible use of a hydrogen bomb.
VOA: special.2009.06.14
He has two electrons here with the same set of quantum numbers. B but these are two separate hydrogen atoms.
因为我写了两个量子数,一样的电子,但这是在两个不同原子中啊。
In the early 1850s, Angstrom, up at the University of Uppsala in Sweden was conducting experiments on atomic hydrogen.
在19世纪50年代的头几年,阿姆斯特朗,那时还在瑞典的乌普萨拉大学里,做了一个有关氢原子的实验。
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