منابع مشابه
Tuning the Clock : Uranium and Thorium
We obtain age estimates for the progenitor(s) of the extremely metal-poor ([Fe/H = −2.9) halo star CS 31082-001, based on the recently reported first observation of a Uranium abundance in this (or any other) star. Age estimates are derived by application of the classical r-process model with updated nuclear physics inputs. The [U/Th] ratio yields an age of 13±4 Gyr or 8±4 Gyr, based on the use ...
متن کاملEvolution of uranium and thorium minerals
The origins and near-surface distributions of the ~250 known uranium and/or thorium minerals elucidate principles of mineral evolution. This history can be divided into four phases. The first, from ~4.5 to 3.5 Ga, involved successive concentrations of uranium and thorium from their initial uniform trace distribution into magmatic-related fluids from which the first U4+ and Th4+ minerals, uranin...
متن کاملConfigurational analysis of uranium-doped thorium dioxide
While thorium dioxide is already used industrially in high temperature applications, more insight is needed about the behaviour of the material as part of a mixed-oxide (MOX) nuclear fuel, incorporating uranium. We have developed a new interatomic potential model, commensurate with a prominent existing UO2 potential, to conduct configurational analyses of uranium-doped ThO2 supercells. Using th...
متن کاملAlpha-recoil thorium-234: dissolution into water and the uranium-234/uranium-238 disequilibrium in nature.
The rate of ejection of alpha-recoil thorium-234 into solution from the surface of zircon sand gives an alpha-recoil range of 550 angstroms. The alpha-recoil thorium-234 atoms ejected into the groundwater may supply excess uranium-234. In pelagic sediments, ejected alpha-recoil thorium-234 may contribute to the supply of mobile uranium-234 in the sedimentary column.
متن کاملa study of the fifth child and ben in the world by doris lessing in the light of julia kristevas psychoanalytic concepts
این مطالعه به بررسی عوامل روانشناختی کریستوادردو رمان دوربس لسینگ،فرزندبنجم و بن دردنیای واقعی می بردازد.موفقیت یا شکست کاراکترهادر تکمیل شکست تتیزی یه کمک بدر وهم از مهم ترین دغدغه محقق می باشد.به بررسی تحلیل روانشناختی تمامی کاراکترها خصوصا بن برداخته و به دنبال نشانه هایی از جامعه شیشه ای کریستوا می باشد.
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ژورنال
عنوان ژورنال: Journal of Geography (Chigaku Zasshi)
سال: 1956
ISSN: 0022-135X,1884-0884
DOI: 10.5026/jgeography.65.1