但是，相对于仅使用一个方法测试放射性衰变，研究人员测定时使用了三种元素，铅，钐，钕。
But rather than test the radioactive decay using just one method, the researchers used three, involving the elements lead, samarium and neodymium.
最为有名的就是铀- 238衰变为铅- 206的半衰期为45亿年，当然放射性铷和钐也同样对测算几十亿年前的物体的年龄很有用。
Most famously, uranium-238 decays into lead-206 with a half life of 4.5 billion years, though radioactive rubidium and samarium are also useful for dating things billions of years old.
铅同位素结果研究表明，穆家庄铜矿矿石铅和近矿围岩岩石铅具有富含放射性成因铅的特点。
Lead isotope research shows that lead in ores of Mujiazhuang copper deposit and near ore country rocks is characterized by being rich in radioactive lead.
目的通过对放射防护中可视面积对迷路口的剂量影响分析，为正确选择防护门铅当量提供参考依据。
Purpose Pass to analysis of relations between the eyeable area and radiate dosage at maze, provide a reference for right choice of the lead equivalent of the protection door.
沥青铀矿中的初始铅属地壳放射成因。
The initial lead in pitchblende belongs to radioactive origin from crust.
目的：检验低熔点铅挡块的制作是否符合常规放射治疗的要求及其质量保证和质量控制的方法。
Objective To detect whether the make of the low melting-point lead block coincides with the request of routine radiation treatment and check the quality control of this method.
具有高放射性异常铅的穆家庄铜矿床位于南秦岭造山带柞(水)山(阳)地区的泥盆系中。
The Mujiazhuang copper deposit with high radioactive lead isotope compositions is located in Zha-shan area of the South Qinling Orogenic Belt.
雅满苏组比企鹅山群富放射成因铅，也具有弱富集的特征。
The Yamansu Formation has more radiogenic lead than the Qi'eshan Group and also shows the weak enrichment character.
对于料位开关，检测器的支架总是高于放射源铅灌的支架。
For level switch, the bracket of the detector is always higher than the bracket of the shielding.
对于料位开关，检测器的支架总是高于放射源铅灌的支架。
For level switch, the bracket of the detector is always higher than the bracket of the shielding.
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