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- Abstract The discovery history of Polonium and Radium are briefly retrospected here at the 110th anniversary of these natural radioactive elements discovery. 摘要 在天然放射性元素钋和镭发现110周年之际，简要回顾了这两种元素的发现史.
- A naturally occurring or artificially produced radioactive element. 放射性元素自然产生或人为制造的放射性元素
- natural radioactive element 天然放射性元素
- Radium is a radioactive element. 镭是个放射性元素。
- Radium and uranium are radioactive elements. 镭和铀是放射性元素。
- Like Galileo, Cassini is powered by the natural decay of the radioactive element plutonium, which generates heat that is then converted to electricity. 如同伽利略号，卡西尼号的能源来自放射性元素钸的自然衰变，产生热后再转换成电。
- Polonium is a naturally radioactive metallic element. 钋是一种具有天然辐射性的金属元素。
- Polonium is a highly radioactive element and a metalloid. 钋是高放射性的元素,金属。
- Radium and uraniumare radioactive elements. 镭和铀是放射性元素。
- How many radioactive elements do you know? 你知道多少种放射性元素?
- An Investigation on Natural Radioactive Lev-els and Their Distribution in Liangshan Regi-on, Sichuan Province. 凉山州天然放射性水平及其分布
- Alpha particles are positively charged helium nuclei obtained from natural radioactive decay. 粒子是从天然放射性蜕变得到的带正电的氦核。
- As a product from the uranium disintegration, radon is a natural radioactive idle gas. 氡是天然放射性惰性气体,是铀系衰变链中的一个衰变产物。
- The decomposition of a radioactive element is the simplest example of a true first order reaction. 放射性元素的衰变是真正一级反应最简单的实例。
- This paper summarizes the quality assurance work of external exposure mea-surement for national survey of environmental natural radioactive level. 本文总结了全国环境天然放射性水平调查外照射测量的质量保证工作。
- A report is made on the results of analysis the content of natural radioactive nuclide in 33 samples of building stone commonly used in South Fujian. 报道闽南常用石材的33个样品中,天然放射性核素含量的分析结果,并按照国家有关石材产品分类标准进行划分。
- A naturally radioactive, silvery, metallic transuranic element, occurring in uranium ores and produced artificially by neutron bombardment of uranium. 钚：一种天然地放射性银色超铀金属元素，存在于铀矿中，对铀元素进行中子轰击而人工制成。
- No colour and no smell, arising from the decay of radium, is the only natural radioactive inert natural gas, the proportion is 7.5 times the air. 没有颜色也没有任何气味，由镭衰变而产生，是自然界惟一的天然放射性惰性气体，比重是空气的7.;5倍。
- KREEP rocks formed at the boundary of lunar crust and mantle, and natural radioactive thorium is one of the elements to demonstrate KRREP rocks distribution. 月球KREEP岩石形成于壳幔的分界层中,天然放射性元素Th是指示KREEP岩分布的主要元素之一。
- Radon and its daughters not only are the decay product of natural radioactive uranium series and thorium series, but also are one of natural radiation source. 氡及其子体是天然放射性系列中的铀系、钍系衰变产生的,是人类受天然辐射主要的来源之一。
