Results 11 to 20 of about 13,316 (289)
Absolute isotopic abundance of terrestrial silver
Journal of Research of the National Bureau of Standards Section A: Physics and Chemistry, 1962 Isotopic abundance ratios are reported for a commercial silver nitrate, 13 samples of native silver, and 11 silver minerals of various compositions and from widely distributed deposits. Collateral measurements of known mixtures of nearly pure silver isotopes permit the determination of absolute abundance ratios.
Shields, William R. +2 more
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The Astrophysical Journal, 2023 We present the first isotopic abundances of both ^13 CO and C ^18 O in solar twin stars and test the results against several galactic chemical evolution (GCE) models with different nucleosynthesis prescriptions.
David R. Coria +5 more
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Frontiers in Astronomy and Space Sciences, 2021 Among presolar grains, oxide ones are made of oxygen, aluminum, and a small fraction of magnesium, produced by the 26Al decay. The largest part of presolar oxide grains belong to the so-called group 1 and 2, which have been suggested to form in Red Giant
S. Palmerini +11 more
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Sm and Gd Isotopic Shifts in Eucrites and Implications for Their Cosmic-Ray Exposure History
The Astrophysical Journal, 2023 The isotopic compositions of Sm and Gd in eight eucrites—five from a desert, Dar al Gani (DaG) 380, DaG 391, DaG 411, DaG 443, and DaG 480, and three from nondesert areas, Juvinas, Millibillillie, and Stannern—were determined to understand the cosmic-ray
Takaharu Saito +2 more
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Cold Deuterium Fractionation in the Nearest Planet-forming Disk
The Astrophysical Journal, 2023 Deuterium fractionation provides a window into the thermal history of volatiles in the solar system and protoplanetary disks. While evidence of active molecular deuteration has been observed toward a handful of disks, it remains unclear whether this ...
Carlos E. Romero-Mirza +9 more
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Neon in interior of the asteroid Vesta and comparison with the terrestrial planets
Journal of Asian Earth Sciences: X, 2022 We investigate the neon isotopic composition and elemental abundance in eucrites and diogenites and compare them with the inventories from interiors of the terrestrial planets.
Satvika Jaiswal +2 more
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AGB Stars and Their Circumstellar Envelopes. I. the VULCAN Code
Universe, 2021 The interplay between AGB interiors and their outermost layers, where molecules and dust form, is a problem of high complexity. As a consequence, physical processes like mass loss, which depend on the chemistry of the circumstellar envelope, are often ...
Sergio Cristallo +4 more
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Frontiers in Ecology and Evolution, 2023 Contemporary methods used to predict isotopic variation at regional scales have yet to include underlying distributions of the abundance of isotopic substrates.
John L. Berini +6 more
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Isotopic Abundances in Comets [PDF]
Symposium - International Astronomical Union, 1987 It is belived that the unprocessed material of the solar nebula may be preserved in comets. Thus the data concerning the chemical composition and the abundance of stable isotopes in these primitive bodies are of some importance in cosmological and cosmogonical context.
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Proceedings of the Indian Academy of Sciences - Section A, 1935 The relative abundance of the isotopes of platinum is estimated from an analysis of the microphotograms of the structure pattern of Pt I λ 3408·13 A (a3F4—z5D4°). Assuming a positive isotope shift, the isotopes of platinum with their relative abundance are as follows:— Mass Number .. 196 195 194 192 Relative abundance ..
Venkatesachar, B., Sibaiya, L.
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