相关概念视频
01:12Isotopes
65.9K
Elements have a set number of protons that determines their atomic number (Z). For example, all atoms with eight protons are oxygen; however, the number of neutrons can vary for atoms of the same element. The sum of the number of protons and the number of neutrons is the mass number (A). Atoms with the same atomic number but different mass numbers are called isotopes. Elements can have multiple isotopes, for example, carbon-12, carbon-13, and carbon-14.
An element's atomic mass, or weight,...
An element's atomic mass, or weight,...
65.9K
02:48Radioactive Decay and Radiometric Dating
42.2K
Radioactivity is a spontaneous disintegration of an unstable nuclide and is a random process, as all the nuclei in the sample do not decay simultaneously. The number of disintegrations per unit time is called the activity (A), which is directly proportional to the number of nuclei in the sample. The decay constant (λ) is an average probability of decay per nucleus in unit time.
42.2K
01:13Mass Spectrometry: Isotope Effect
5.1K
Most elements exist in nature as a mixture of isotopes. The isotopes differ in weight due to their respective number of neutrons. The molecular weight of a molecule is different depending on the specific isotope of its elements involved. As a result, the mass spectrum of the molecule exhibits peaks from the same fragment at multiple positions. The positions of these mass signals depend on the mass differences between isotopes. Furthermore, the intensity of these signals is dependent on the...
5.1K
01:25Applications Of NMR In Biology
4.8K
Nuclear magnetic resonance (NMR) spectroscopy is a very valuable analytical technique for researchers. It has been used for more than 50 years as an analytical tool. F. Bloch and E. Purcell formulated NMR in 1946 and won the 1952 Nobel Prize in Physics for their work. Biological macromolecules such as proteins, nucleic acids, lipids, and organic molecules including pharmaceutical compounds, can be studied using this versatile tool that exploits the magnetic properties of certain nuclei.
4.8K
01:28Isotopes and Radioisotopes
13.9K
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...
An isotope containing...
13.9K
01:11Applications of IR Spectroscopy: Overview
3.0K
The non-destructive nature and ability to provide valuable chemical information make IR spectroscopy a versatile technique with broad applications in various scientific and industrial fields. IR spectroscopy is commonly used to identify and characterize organic and inorganic compounds. It provides information about the functional groups present in a molecule and the bonding between atoms. This helps in the structural elucidation of compounds during organic synthesis, pharmaceutical research,...
3.0K
您也可能阅读
相关文章
通过共同作者、期刊和引用图与本文相关的文章。
排序
Same author
Pseudo-natural products: a decade of exploration and potential opportunity.
Natural product research·2026
Same author
Oxygen-17 NMR: a valuable and underexplored natural product opportunity.
Natural product research·2026
同位素在法医科学中的应用.
1Revvity, Inc., Waltham, Massachusetts, USA.
Journal of labelled compounds & radiopharmaceuticals
|March 28, 2025
概括
同位素提供了强大的法医工具,有助于从野生动物走私到假冒药物的调查. 本综述探讨了在各种法医科学领域的同位素应用,包括核法医和人工智能.
科学领域:
- 法医科学 法医科学 法医科学
- 分析化学 分析化学
背景情况:
- 同位素的概念在20世纪初出现,得到了重要的实验发现的支持.
- 同位素分析已成为各种科学学科的关键技术.
研究的目的:
- 审查同位素在法医科学中的多样化应用.
- 突出同位素比测量在法医调查中的作用.
主要方法:
- 对法医学中同位素应用现有文献的审查.
- 讨论同位素比测量技术和变化.
主要成果:
- 同位素适用于法医人类学,野生动物贩运,爆炸物,非法药物和假冒药品.
- 同位素分析对食品认证和核取证有价值.
- 人工智能 (AI) 正在成为基于同位素的法医分析的工具.
结论:
- 同位素分析为法医调查提供了一种通用而强大的方法.
- 未来的研究方向包括进一步整合人工智能和先进的分析技术.
