deuterium fractionation barxâneš-e doteriom Fr.: fractionnement de deutérium The difference between the deuterium (D)/hydrogen (H) → abundance → ratio in an object with respect to that representing a standard or mean value for that type of objects. Same as → isotope fractionation of deuterium. In the gas phase chemistry many of the D fractionation reactions produce an excess of D atoms relative to → hydrogen atoms. Deuterium fractionation in → interstellar cloud cores, → protostars, and → Solar System bodies is frequently used to infer important aspects of their physical and chemical histories. For example, the → deuterium enhancement in the Earth's sea water, with respect to the cosmic abundance, has been interpreted as being due to → enrichment by → comet-like → planetesimals colliding with the young Earth. → deuterium; → fractionation. |
fractionation barxâneš Fr.: fractionnement 1) Any of various methods of separating the components of a mixture into
fractions of different properties. Verbal noun from → fractionate. |
isotope fractionation barxâneš-e izotopi Fr.: fractionnement isotopique A slight difference between the → abundances of → isotopes of the same → chemical element owing to → physical or → chemical → processes. It results in the → enrichment or → depletion of an isotope. Same as → isotopic fractionation. → isotope; → fractionation |
isotopic fractionation barxâneš-e izotopi Fr.: fractionnement isotopique Same as → isotope fractionation. → isotopic; → fractionation |