نتایج جستجو برای: niobium

تعداد نتایج: 3152  

2016
Jascha Bandemehr Matthias Conrad Florian Kraus

Single crystals of NbF4, niobium(IV) tetra-fluoride, were synthesized by disproportionation of Nb2F5 at 1273 K in a sealed niobium tube, extracted and studied by single-crystal X-ray diffraction. Previous reports on the crystal structure of NbF4 were based on X-ray powder diffraction data and the observed isotypicity to SnF4 [Gortsema & Didchenko (1965 ▸). Inorg. Chem. 4, 182-186; Schäfer et al...

2010
Yanbo Shi Ian Harvey Dominic Campopiano Peter J. Sadler

Ferric ion binding proteins (Fbps) transport Fe(III) across the periplasm and are vital for the virulence of many Gram negative bacteria. Iron(III) is tightly bound in a hinged binding cleft with octahedral coordination geometry involving binding to protein side chains (including tyrosinate residues) together with a synergistic anion such as phosphate. Niobium compounds are of interest for thei...

2003
Fakhili Gulo

SYNTHESIS AND CRYSTAL STRUCTURE OF CS3NB2BR9, A DINUCLEAR NIOBIUM CLUSTER. The niobium bromide cluster compound, Cs3Nb2Br9, was obtained by solid-state synthesis techniques in reaction of stoichiometric amounts of CsBr, Nb powder and NbBr5. It crystallizes in the hexagonal system with unit cell parameters a = 7.7183(2) Å, c = 18.3396(7) Å, space group P63/mmc, Z = 2. Its crystal structure was d...

2011
J. D. Splett D. F. Vecchia L. F. Goodrich

We compare methods for estimating the residual resistivity ratio (RRR) of high-purity niobium and investigate the effects of using different functional models. RRR is typically defined as the ratio of the electrical resistances measured at 273 K (the ice point) and 4.2 K (the boiling point of helium at standard atmospheric pressure). However, pure niobium is superconducting below about 9.3 K, s...

2017
Darí Cesarín-Sobrinho Aurélio Baird Buarque Ferreira José Carlos Netto-Ferreira

The catalytic properties of niobium(V) oxide (Nb2O5-CBMN) of different grades: amorphous, optical and ultra-pure, untreated or heat-treated at 400, 500, 700 and 900 ◦C were studied, before and after interaction with H2O2, by in situ Raman, FTIR-ATR and diffuse reflectance UV-Visible spectroscopy. The presence of different reaction sites for NbO7 and NbO8 type systems, which are directly related...

Journal: :The Journal of the Society of Chemical Industry, Japan 1971

Journal: :Dalton transactions 2012
Marco Bortoluzzi Nicola Guazzelli Fabio Marchetti Guido Pampaloni Stefano Zacchini

The synthesis and the spectroscopic characterization of fluoride-alkoxides of niobium and tantalum in the highest oxidation state are reported. Suspensions of MF(5) (M = Nb, Ta) in a chlorinated solvent reacted with up to three equivalents of ROSiMe(3) (R = Me, Et, Ph) to afford polynuclear derivatives and variable amounts of FSiMe(3). Thus MF(4)(OR) (R = Et, Ph) and MF(3)(OR)(2) were obtained ...

2009
Emiliano Pallecchi Sergey Ganichev Christoph Strunk Milena Grifoni Jascha Repp

2013
M. BastaniNejad Abdullah Mohamed A. A. Elmustafa P. Adderley Thomas Jefferson J. Clark P. Williams K. Surles-Law

This Article is brought to you for free and open access by the Mechanical & Aerospace Engineering at ODU Digital Commons. It has been accepted for inclusion in Mechanical & Aerospace Engineering Faculty Publications by an authorized administrator of ODU Digital Commons. For more information, please contact [email protected]. Repository Citation BastaniNejad, Mahzad; Abdulla Mohamed, Md.; E...

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