名詞 radioactivity:

1. the spontaneous emission of a stream of particles or electromagnetic rays in nuclear decay
   同義詞：radiation

1. A damaged reactor leaking radioactivity into the atmosphere.
   一座損壞的反應(yīng)堆向大氣中泄露出發(fā)射性物質(zhì)
2. Russian-born American nuclear physicist known for his work on radioactivity and genetic information as well as his books popularizing theories of physics.
   伽莫夫，喬治1904－1968俄國裔的美國核物理學(xué)家，因在射線遺傳信息方面的研究和有關(guān)普及物理理論的書籍而聞名于世
3. Relating to or caused by radioactivity.
   放射產(chǎn)生的關(guān)于放射性的或由放射性引起的

ra.di.o.ac.tiv.i.ty

n.（名詞）
Spontaneous emission of radiation, either directly from unstable atomic nuclei or as a consequence of a nuclear reaction.
自動放射：自動地發(fā)出輻射，直接源于不穩(wěn)定的原子核或是作為核反應(yīng)的結(jié)果
The radiation, including alpha particles, nucleons, electrons, and gamma rays, emitted by a radioactive substance.
輻射：由一種放射性物質(zhì)發(fā)出的輻射，包括α粒子、原子核、電子、和γ射線