1. Background 2. Elements, Nuclides, and Stable Isotopes 3. The Mass Spectrometer and Isotope Ratio Measurement 4. Isotope Fractionation 5. Temperature and Fractionation 6. Stable Isotopes in the Hydrologic Cycle 7. O in Minerals and Rocks 8. C and Carbon Cycling 9. N Cycling in Watersheds 10.S and the Sulfur Cycle 11. Chlorine and Bromine Isotopes 12. Light Lithophile Elements: δLi and δB Glos...

The pH-dependent hydrogen isotope exchange reaction between gaseous isotopes and medium isotopes and hydrogenation of the carbonyl compounds have been investigated with water-soluble bis(mu-thiolate)(mu-hydride)NiRu complexes, Ni(II)(mu-SR)(2)(mu-H)Ru(II) {(mu-SR)(2) = N,N'-dimethyl-N,N'-bis(2-mercaptoethyl)-1,3-propanediamine}, as functional models for [NiFe]hydrogenases. In acidic media (at p...

We studied firstly the ground state properties of C-isotopes using a deformed Hartree-Fock (HF)+ BCS model with Skyrme interactions. Shallow deformation minima are found in several neutron−rich C-isotopes. It is shown also that the deformation minima appear in both the oblate and the prolate sides in 17C and 19C having almost the same binding energies. Secondly, we carried out shell model calcu...

Chemical, biological, and physical processes lead to distinctive "isotopic signatures" in biological materials that allow tracing of the origins of organic substances. Isotopic variation has been extensively used by plant physiological ecologists and by paleontologists, and recently ecologists have adopted the use of stable isotopes to measure ecosystem patterns and processes. To date, animal p...

The separation of isotopes in space and time by gas-surface atomic diffraction is presented as a new means for isotopic enrichment. A supersonic beam of natural abundance neon is scattered from a periodic surface of methyl-terminated silicon, with the ^{20}Ne and ^{22}Ne isotopes scattering into unique diffraction channels. Under the experimental conditions presented in this Letter, a single pa...

The reaction of CO2 hydration/dehydration controls the oxygen isotopic composition in both carbonate minerals and atmospheric CO2 through the exchange of oxygen isotopes with water. The use of O as an environmental indicator typically assumes isotopic equilibrium, namely full oxygen isotope exchange between CO2 and water. Clumped isotopes is a new isotopic tracer that is used in both CaCO3 and ...

Neutron-rich Zr and Mo isotopes were populated as fission fragments produced by the 238Usa, fd fusionfission reaction. The level schemes of these nuclei have been extended beyond the first band crossing region, which can be ascribed to the h11/2 neutron pair alignment. The spin alignment and signature splitting for the nh11/2 orbitals in term of triaxiality is addressed. The crossing frequency ...

a three-step selective photo-ionization for gd155 and gd157 isotopes by pulsed laser wasevaluated numerically. due to large thermal neutron absorption cross sections, these two isotopes innatural gadolinium are good candidates as burnable poison to control reactivity early in the fuel cycleand allow extended fuel burn up. rate equations have been used to calculate the dynamics of the isotopepop...

for more than half a century isotopes have been employed as a powerful tool in studying various aspects of water resources in a largenumber of countries. however, in developing countries like iran the application of such techniques is in its infancy. the first research iniran was carried out in 1975 to identify the source of saline groundwaters in south iran, and the first national conference o...