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).

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）。

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Heavy water gets its name because it contains deuterium, a form of hydrogen that has a neutron in its nucleus as well as the usual proton and thus weighs twice as much as the ordinary sort.

重水因含重氢而得名。重氢是氢原子的一种，其原子核中含有一枚中子，加之正常氢元素中的质子，重量为一般氢原子的两倍。

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The departing halide extracts a proton from the second water and the generated hydroxyl ligand reacts with the ethylene, while remaining in the coordination sphere of the metal.

分开的卤化物从第二个水分子得到一个质子，同时产生的羟基配合体与乙烯反应，留在了金属的配位区内。

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The energy stored in xylose splits water molecules, yielding high-purity hydrogen that can be directly utilized by proton-exchange membrane fuel cells.

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