四种基本力（万有引力、电磁力、强核力和弱核力）中的每一种都有一个理论上的旋钮。
Each of the four fundamental forces (gravity, electromagnetism, and the strong and weak nuclear forces) has a kind of theoretical knob.
之后会出现强核力占主导作用的短距效应，进而，原子聚合成为氦。
This allows a short-range phenomenon called the strong nuclear force to take over and causes the nuclei to merge and form helium.
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.
和宇宙中的其他三种力(电磁力、弱核力、强核力)相比，重力就微弱得多了，所以引力波很难被观测。
Compared with the other three forces in the universe (electromagnetism, the weak nuclear force and the strong nuclear force), gravity is relatively feeble, making gravitational waves hard to detect.
尽管目前有了很多关于核力，核子-核子相互作用甚至是强相互作用的理论，但是各种理论或模型都或多或少地存在一些困难。
At present, though there are many theories about nuclear power and nucleon-nucleon interaction, more difficulties exist in both of these theories or models more or less.
尽管目前有了很多关于核力，核子-核子相互作用甚至是强相互作用的理论，但是各种理论或模型都或多或少地存在一些困难。
At present, though there are many theories about nuclear power and nucleon-nucleon interaction, more difficulties exist in both of these theories or models more or less.
应用推荐