Electron energy loss spectra in conjunction with near-edge fine structures of purely stoichiometric niobium monoxide (NbO) and niobium pentoxide (Nb2O5) reference materials were recorded. The structures of the niobium oxide reference materials were checked by selected area electron diffraction to ensure a proper assignment of the fine structures. NbO and Nb2O5 show clearly different energy loss...

A series of niobium and tantalum imido complexes with mono-anionic ortho-metallated acetophenone imine ligands have been prepared and characterized using NMR spectroscopy, mass spectrometry and elemental analysis. These low symmetry complexes are produced with only one or two structural isomers in all cases and display interesting correlations between the steric bulk of the ligands employed and...

Transition metal oxides are considered as prototype models of reactions involving oxidative processes [1]. In this way, the detailed understanding of their electronic and molecular structure is of great interest in the prediction of their catalytic behavior and chemical reactivity toward inert organic molecules which are of industrial interest. In particular, it is possible to highlight the sel...

the equilibrium constant of adduct formation between some triorganotin chloride of the type r3sncl (r=c6h5, p-ch3c6h4, n-ch3)ch2)3, c6h5-ch2 and lewis bases cl¯, br¯, and i¯, were measured in 50% v/v ethanol-water solvent spectrophotometrically. the average equilibrium constant values for the systems studied shows the following acceptor trend of tin(iv) in the triorganotin chlorides: p-tolyl > ...

Characteristics of the anion conductance of muscle fibres from green sunfish have been determined. The membrane conductance of fibres from sunfish acclimated to 25 and 7 degrees C was linearly related to the extracellular chloride concentration. The chloride conductance exhibited a pH dependence which was adequately described by the titration of an acidic site with a pKa of 5.3 in 25 degrees C-...

Measurements at 8.6 GHz on TM mode superconducting niobium cavities have been carried out at SLAC in an attempt to establish definitive conditions for reproducibly attaining high peak electric and magnetic fields and high residual &Is. Four cavities, processed by techniques which insure thepresence of an oxi& layer on the niobium surface before final high temperature outgassing, have given peak...

The far-infrared vibrational spectra for charged vanadium clusters as well as charged and neutral niobium clusters have been measured size specifically using farinfrared multiple photon dissociation. The ground state energy and vibrational spectra of a large number of stable and metastable structures for each of these sizes and systems have also been calculated using densityfunctional theory (D...

The study discusses the microstructure and mechanical properties of eight tested 0.3 % C -30 % Ni 18 % Cr cast steels stabilized with niobium and titanium after annealing in the cycle of 900 °C / 300 h. The niobium content in the cast steels varied from 0.0 to 2.0 % and that of titanium from 0.0 to 1.2 % by weight. Microstructure was examined using both light microscope and a scanning electron ...

Aim. Strontium salts are effective and selective anti-irritants for chemically induced sensory irritation associated with stinging, burning, or itching. The aim of the present study was to determine the cytotoxic and/or proliferative effects of strontium chloride on fibroblast cell culture. Method. A mouse connective tissue fibroblast cell line, L929 (ATCC cell line, NCTC clone 929) was culture...

Niobium and tantalum carbide clusters have been isolated in the gas phase and irradiated with intense tunable infrared (IR) light. Stable neutral clusters are selectively ionized and subsequently detected in a mass spectrometer. By tuning the IR frequency, infrared multiphoton absorption spectra are obtained for a whole range of clusters. These mass-selective IR spectra lead to insights into th...