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夜光表上的发光体不止一种。有的含有放出甲种射线的同位素,如鐳和釙;有的含有只放出乙种射线的同位素,如氚、碳~(14)、硫~(35)、氪~(85)、锶~(90)、钜~(147)和铊~(204);有的根本不含放射性物质,只含有能发磷光的硫化鋇等。許多放出甲种射线的同位素同时又放出丙种射綫。有的发光体是含有几种放射性物质混合物的。由此可見,各补发光体的理化性质很不相同,对人体是否有危害,不能一概而論。甲种射綫的穿透力很弱。乙种射綫大部或全部破手表的玻璃擋住。丙种射线虽然能穿透玻璃和皮肤,但是,它的体外照射剂量随着距离增加而大大下
There are more than one kind of luminous body on the luminous watch. Some contain isotopes emitting a type of radiation, such as radium and cesium; others contain isotopes emitting only gamma rays, such as helium, carbon-14, sulfur35, helium85, and thorium. 90), 钜 ~ (147) and 铊 ~ (204); some do not contain radioactive substances, only containing phosphorescent osmium sulphide and so on. Many isotopes that emit a type of radiation emit gamma rays at the same time. Some light emitters contain a mixture of several radioactive substances. It can be seen from this that the physicochemical properties of the supplemental luminophors are very different and they are not harmful to the human body and cannot be generalized. A type of ray penetration is weak. Most of the B rays are blocked by the glass of the broken watch. Although the gamma ray penetrates the glass and the skin, its external irradiation dose greatly decreases with distance.