| 释义 |
半衰期bànshuāiqī放射性元素由于衰变而使原有量的一半成为其他元素所需的时间。放射性元素的半衰期长短差别很大,短的远小于一秒,长的可达许多万年。{half-life; period required for the radioactivity of a radioactive substance, due to disintegration, to fall to half of its original value. Radioactive elements vary enormously in their half-life, the shortest lasting less than one second, the longest tens of thousands of years.} |