It is the 110 th anniversary of the discovery of natural radioactive elements,Polo- nium and Radium.
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。
With the development of science and technology,people known about the radioactive elements more and more.
随着科技的发展,人们对放射性元素的认识日益加深,普通百姓越来越关注放射性元素对生活的影响。
U and Th are radioactive elements.
U和Th是放射性元素,K、Fe、Mo、Mg和Zn是植物生长需要的必要营养元素。
The radon and its daughter elements are the decay products of the radioactive elements such as uranium and thorium and the important carcinogenic factor of causing the lung cancer.
氡及其子体是铀、钍等放射性元素产物，是引发肺癌的重要致病因子。
The field investigation opens out the secret of the harm by radioactive elements to the health of some villagers around Anshan.
通过实地调查,揭示了鞍山周边部分村民受放射性元素致害之迷。
The radioactive element distribution in the granulites and charnockites of the Precambrian basement of Yunkai,Western Guangdong,has been determined.
粤西云开前寒武纪基底的麻粒岩、紫苏花岗闪长岩和紫苏闪长岩的放射性元素分布具有明显的规律，Ｋ／Ｒｂ比值分别为１１７～２０２，９４～１２９，７８～８９，Ｔｈ／Ｕ比值分别为１５～３０，１１～２０，２５～７８，Ｕ的含量范围分别为０。
lead box for transportation of radio active element
放射性元素运输铅罐
the unknown radioactive element
不知名的放射性元素
Radium and uranium are radioactive elements.
镭和铀是放射性元素.
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
These artificial radio-elements behave in all respects like the natural radio-elements.
这些人造的放射性元素在各方面的表现和天然的放射性元素一样。
a radioactive element of the actinide series; found in uranium ores.
锕类的放射性元素，见于铀矿中。
cermet containing radioactive elements
含放射性元素的金属陶瓷
Half-life of radioactive element carbon-14 is 5730 year.
放射性元素碳-14的半衰期为5730年。
Other radioactive elements have been discovered since: actinium, radiothorium and mesothorium, ionium, etc.
自那以后发现的其他放射性元素有：锄、放射性钍和新针、镍，等等。
On the basis of distribution of radioactive elements and geological background , the theory equation of radon exhalation rate is derived from the decay rule of radioactive elements and gas diffusion.
根据放射性元素分布规律、地质背景及放射性元素衰变等，建立了计算氡析出率的理论公式。
any element having an atomic number greater than 92" (the atomic number of uranium); all are radioactive.
原子序数在以后（铀的原子序数）的元素，都是放射性元素。
The rate at which radioactive elements disintegrate varies from one element to another.
放射性元素的衰变速度随元素种类的不同而不同。
a radioactive element of the alkali-metal group discovered as a disintegration product of actinium.
一种碱金属属的放射性元素，是锕瓦解的产物。
dispersion, of ceramic products and mixtures containing radioactive elements
含放射性元素的陶瓷产品和混合物的分散体
a series of 15 radioactive elements with increasing atomic numbers from actinium to lawrencium.
15个从锕到铹的原子量递增的放射性元素。
The immediate product of the radioactive decay of an element.
继承元素某种元素放射性衰变的直接产物
The large number of radioactive isotopes among the heavy elements fit into three series.
重元素中的大量放射性同位素分属于三个系列。
a radioactive transuranic element; discovered by bombarding americium with helium.
一种放射性超铀元素，在用氦轰击镅时发现。