The time necessary for the disappearance of half the atoms, called the half-life, is a fundamental characteristic of each radio-element; 原子消失一半所需的时间,即半排出期,是每一种放射性元素的基本特征。
The Research for Primary Treatment of City Waste Waste Water by using Plastic Tube Containing Low-Component Radio-Element 利用低剂量放射管处理城市污水