| 释义 |
> as lemmaselementary particle elementary particle n. now used in Physics spec. for any of a number of particles smaller than an atom (the leptons, mesons, and baryons) which are not known to be composed of any simpler particles and which are characterized by having a definite mass, a lifetime that is long compared with the interaction time, and well-defined electromagnetic properties, and are capable of an independent existence.< |