相关实验视频
Updated: Jul 12, 2026

10:42
Preparing an Isotopically Pure 229Th Ion Beam for Studies of 229mTh
Published on: May 3, 2019
在 Mare tranquillitatis 表面材料中发现的和同位素
概括
来自阿波罗11号月球样本的比以前研究过的任何都更古老,更有放射性. 这种月球的领先作用为早期太阳系和行星形成过程提供了洞察力.
科学领域:
- 地质化学 地质化学
- 宇宙化学 宇宙化学
- 行星科学 行星科学
背景情况:
- 同位素分析对于理解行星的形成和进化至关重要.
- 由于其保存,月球样本为早期太阳系提供了独特的见解.
研究的目的:
- 为了确定阿波罗11号飞船中的同位素组成和的年龄.
- 将月球与地球和石进行比较,以了解其起源和影响.
主要方法:
- 同位素比率分析 (206Pb/204Pb,207Pb/204Pb,208Pb/204Pb). 这是一个非常简单的方法.
- 与石岩和陆地的同位素数据进行比较.
- 计算-等离子年代和U-Pb,Th-Pb比率.
主要成果:
- 阿波罗11号的具有独特的,高度放射性同位素特征 (206Pb/204Pb/207Pb/204Pb/208Pb/204Pb = 1/99.6/69.0/117.1).
- 确定了207Pb/206Pb年龄为4.7±0.1亿年,这表明它是古代形成的.
- 观察到高 (238U/204Pb > 90) 和 (232Th/238U = 3.9 ± 0.1) 缩,耗尽.
结论:
- 阿波罗11号飞船罚款中的比任何已知的陆地放射性更古老,并且比之前报告的石更放射性.
- 这些发现表明,在这个月球材料的形成过程中,和U和Th的缩和丰富显著地减少了.
- 这些数据支持在月球样本中观察205Pb灭绝的自然放射性的潜力.
相关概念视频
Isotopes and Radioisotopes
In the early 1900s, English chemist Frederick Soddy realized that an element could have atoms with different masses that were chemically indistinguishable. These different types are called isotopes — atoms of the same element that differ in mass. Isotopes differ in mass because they have different numbers of neutrons but are chemically identical because they have the same number of protons. Soddy was awarded the Nobel Prize in Chemistry in 1921 for this discovery.
An isotope containing more...
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Nuclear Transmutation
Nuclear transmutation is the conversion of one nuclide into another. It can occur by the radioactive decay of a nucleus, or the reaction of a nucleus with another particle. The first manmade nucleus was produced in Ernest Rutherford’s laboratory in 1919 by a transmutation reaction, the bombardment of one type of nuclei with other nuclei or with neutrons. Rutherford bombarded nitrogen-14 atoms with high-speed α particles from a natural radioactive isotope of radium and observed protons being...

