氘氢的一种同位素，在其原子核内有一个质子和一个中子，其原子重量为2。014 An isotope of hydrogen with one proton and one neutron in the nucleus having an atomic weight of2.014.
费密子一种如电子、质子或中子等自旋为半整数的基本粒子，具有一种使得不可能有多于一个的粒子占有任何一个特殊的量子力学态的量子力学对称性 A particle, such as an electron, a proton, or a neutron, having half-integral spin and obeying statistical rules requiring that not more than one in a set of identical particles may occupy a particular quantum state.
核子质子或中心，尤指作为原子核的一个组成部分 A proton or a neutron, especially as part of an atomic nucleus.
