在我们的宇宙中，底夸克的质量大约是顶夸克的两倍，造成中子比质子重大约0.1%。

In our universe, the down quark is about twice as heavy as the up quark, resulting in neutrons that are 0.1 percent heavier than protons.

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Jaffe和他的同事建立了一个类型的宇宙，其中底夸克比顶夸克轻，而质子比中子重1%。

Jaffe and his colleagues modeled one family of universes in which the down quark was lighter than the up quark, and protons were up to a percent heavier than neutrons.

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强核力的一部分也由中子提供，在大多数原子核内，中子比质子数量多，并且不带电荷。

Some of this force is also supplied by neutrons, which outnumber protons in most nuclei and have no electric charge.

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