isotope fractionation
31Isotopic labeling — (or isotopic labelling) is a technique for tracking the passage of a sample of substance through a system. The substance is labeled by including unusual isotopes in its chemical composition. If these unusual isotopes are later detected in a… …
32Donald J. DePaolo — is an American professor of geochemistry in the Department of Earth and Planetary Science at the University of California, Berkeley and Associate Laboratory Director for Energy and Environmental Sciences at the Lawrence Berkeley National… …
33Фракционирование химических элементов в земной коре — Возможно, эта статья содержит оригинальное исследование. Добавьте ссылки на источники, в противном случае она может быть выставлена на удаление. Дополнительные сведения могут быть на странице обсуждения. (11 мая 2011) …
34Dole effect — The Dole effect describes an inequality in the ratio of the heavy isotope 18O (a standard oxygen atom with two additional neutrons) to the lighter 16O, measured in the atmosphere and seawater. This ratio is usually denoted δ18O. It was noticed in …
35Natural abundance — In chemistry, natural abundance (NA) refers to the abundance of isotopes of a chemical element as naturally found on a planet. The relative atomic mass (a weighted average) of these isotopes is the atomic weight listed for the element in the… …
36Thermal ionization — In thermal ionization, also referred to as surface ionization, chemically purified material loaded onto a filament which is then heated to cause some of the material to be ionized as it boils off the hot filament. Filaments are generally flat… …
37100,000-year problem — The 100,000 year problem is a discrepancy between past temperatures and the amount of incoming solar radiation, or insolation, which grows and shrinks periodically on a 100,000 year (100 ka) timescale.Due to variations in the Earth s orbit, the… …
38MÉTÉORITES — Les météorites sont des objets naturels venant de l’espace et atteignant la Terre. Bien qu’elles aient été signalées dès l’Antiquité, la première des chutes de pierres bien observée, et dont il existe encore des échantillons, est celle qui est… …
39Oxygen-18 — Full table General Name, symbol Oxygen 18,18O or Ω Neutrons 10 Protons 8 …
40Protein mass spectrometry — A mass spectrometer used for high throughput protein analysis. Protein mass spectrometry refers to the application of mass spectrometry to the study of proteins. Mass spectrometry is an important emerging method for the characterization of… …
