نتایج جستجو برای: samarium compounds

تعداد نتایج: 227605  

Journal: :Eurasian Chemico-Technological Journal 2016

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه رازی - دانشکده علوم 1391

in this work, a novel and fast method for direct analysis of volatile compounds (davc) of medicinal plants has been developed by holding a filament from different parts of a plant in the gc injection port. the extraction and analysis of volatile components of a small amount of plant were carried out in one-step without any sample preparation. after optimization of temperature, extraction time a...

Journal: :Journal of Scientific Research 2023

An efficient, simple, and green four-component reaction for synthesizing 1,2,4,5-tetrasubstituted imidazoles is developed. In present work exploring the use of Samarium triflate as a heterogeneous catalyst aldehydes, aromatic amines, benzil, ammonium acetate. The current approach offers many advantages, such excellent yields, shortening time, reusability catalyst, mild conditions.

2017
Fuchang Peng Honglin Gao Genlin Zhang Zhongqi Zhu Jin Zhang Qingju Liu

Mixed phase TiO₂ nanoparticles with element doping by Sm and C were prepared via a facile sol-gel procedure. The UV-Vis light-diffuse reflectance spectroscopy analysis showed that the absorption region of co-doped TiO₂ was shifted to the visible-light region, which was attributed to incorporation of samarium and carbon into the TiO₂ lattice during high-temperature reaction. Samarium effectively...

Journal: :Science 2007
Richard W Carlson Maud Boyet Mary Horan

Isotopic variability in barium, neodymium, and samarium in carbonaceous chondrites reflects the distinct stellar nucleosynthetic contributions to the early solar system. We used 148Nd/144Nd to correct for the observed s-process deficiency, which produced a chondrite 146Sm-142Nd isochron consistent with previous estimates of the initial solar system abundance of 146Sm and a 142Nd/144Nd at averag...

Journal: :Inorganic chemistry 2001
J H Agondanou G A Spyroulias J Purans G Tsikalas C Souleau A G Coutsolelos S Bénazeth

The comparative X-ray absorption spectroscopy study of gadolinium and samarium bisporphyrinate complexes represented by the formulas Gd(III)H(oep)(tpp), Gd(III)(oep)(2), Gd(III)H(tpp)(2) and Sm(III)H(oep)(tpp), Sm(III)(oep)(2), Sm(III)H(tpp)(2) is reported. The XAFS spectra are recorded on the LURE-DCI storage ring (Orsay, France) in transmission mode on the microcrystalline samples at the Gd a...

Journal: :Science 2005
M Boyet R W Carlson

New high-precision samarium-neodymium isotopic data for chondritic meteorites show that their 142Nd/144Nd ratio is 20 parts per million lower than that of most terrestrial rocks. This difference indicates that most (70 to 95%) of Earth's mantle is compositionally similar to the incompatible element-depleted source of mid-ocean ridge basalts, possibly as a result of a global differentiation 4.53...

2010
Dan Zhao Lina Zhang Feifei Li

NaSm(PO(3))(4) has been prepared by solid state reactions. It belongs to type II of the structural family of M(I)Ln(III)(PO(3))(4) compounds (M(I) = alkali metal and Ln(III) = rare earth metal) and is composed of (∞)(PO(3))(n)](n-) polyphosphate chains with a repeating unit of four PO(4) tetra-hedra. The chains extend parallel to [100] and share O atoms with irregular SmO(8) polyhedra, forming ...

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