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自从1895年倫琴第一次发现了X射线之后,一系列的天然放射性元素接踵发现。1934年,约里奥一居里夫妇又发现了人工合成的放射性物质。到今天,天然的和人工合成的放射性元素,已不下千余种之多了。随着原子能在工业、衣业以及医学科学等部门的广泛应用,放射性物质与人们生活的关系愈来愈加密切。所以,人们对放射线的危害和防护知识就不能不关心了。什么是放射性?放射有那些?大家知道,一切物质都是由分子组成的,而分子又是原子构成的,原子的主要部分是原子核。原子核中的粒子,时时刻刻在不断地运动,
Since Roentgen first discovered X-rays in 1895, a series of natural radioactive elements have been discovered. In 1934, Joliot and his family discovered a synthetic radioactive material. Today, natural and synthetic radioactive elements are no less than a thousand species. With the wide application of atomic energy in industries, clothing, and medical science, the relationship between radioactive materials and people’s lives has become increasingly closer. Therefore, people’s knowledge of radiation hazards and protection cannot be ignored. What is radioactivity? What about radiation? Everybody knows that everything is made up of molecules, which are made up of atoms. The main part of atoms is the nucleus. The particles in the nucleus are constantly moving,