radioactive series

Radioactive series: Any of four sets of unstable heavy atomic nuclei that undergo a series of alpha decay and Beta decay until a stable nucleus is achieved.

放射性系：四组不稳定的重原子核，通过一系列α衰变和β衰变直至达到稳定的核为止。

A proof of the secular equilibrium formula in radioactive cascade decay series

放射性递次衰变系列中长期平衡公式的证明

The E-factor method for solving the equations of succesive decay in a radioactive series

放射性递次衰变方程的E因子解法

In this survey, the surface γ dosage, radioactivity specific activity, uranium and thorium series equilibrium, the content of radioactive element of three kinds of typical Chinese zircon mineral has been analyzed, and the component and radioactivity of zircon in Wanning, Hainan Province tested.

调查分析了我国3个典型矿区锆英砂堆放表面γ剂量、放射性比活度、铀系和钍系平衡状况以及放射性元素含量；测定了我国海南万宁矿区锆英砂的组成及放射性。

Heavy-ion 14~ C can not only be directly emitted by three radioactive series ( 238~ U, 235~ U and 232~ Th), but can also be produced by neutrons of the spontaneous fission and α-decay interacting with matter.

由于铀，钍、锕三系能直接发射微量重离子~（14）C，以及自发裂变中子和α-衰变与物质发生核相互作用，也可产生~（14）C。

The results showed that the range of beta ray with the maximum energy in natural radioactive series is longer than thickness of a piece of decorative materials.

结果发现：由于天然放射系中最大能量b粒子的射程大于单块饰材，不能用表面b辐射水平进行无损检测判断；

In the processing and utilization of rare-earth minerals, radioactive thorium series is in radioactive equilibrium basic state in raw ore, concentrate and mineral processing tailings, but in the rare earth products, enrichment, Ce-rich slag and smelting waste, the thorium series is non-radioactive state.

在稀土矿物在加工利用中，原矿、精矿和选矿尾矿中，放射性钍系基本处于放射性平衡状态，但在稀土产品、富集物、富铈渣和冶炼废渣中，钍系处于非放射性状态。

The numerical methods used in analysing the experimental decay data of synthesizing a new heavy neutron rich isotope 239 Pa are studied, and its half life is obtained by analysing the decays of a radioactive series for the first time.

根据合成239Pa实验的特定条件，利用递次衰变关系首次确定了丰中子新核素239Pa的半衰期。

Determination of the half life for a new nuclide 239 pa by analyzing the decays of a radioactive series

利用递次衰变关系确定新核素~（239）Pa的半衰期