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.
非特定的代表某一种类的所有成员或其中一个的；不标志唯一存在的
Representing one or all of the members of a class; not designating a unique entity.
他克服了一个又一个的困难以后才得脱身。
He managed to cash in only after overcoming one difficulty after another.
