beta particle

1. Any of three processes of radioactive disintegration in which a Beta particle is spontaneously emitted by an unstable atomic nucleus in order to dissipate excess energy.
   某些不稳定原子核为耗散其过剩能量而自发发射一个β粒子的三种放射性衰变过程的统称。
2. Alpha and beta particle radiation is lower energy and can often be blocked by just a sheet of paper.
   α和β粒子辐射的能量较低，一页纸片便可以阻挡住它们。

noun

1. a high-speed electron or positron emitted in the decay of a radioactive isotope