Materials Literature
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The tracer diffusion coefficients of 22 Na and 86 Rb and electrical conductivity were measured in a series of 0.56(Na, Rb) 2 S.0.44SiS 2 glasses as a function of the Rb/Na ratio and temperature. The data were used to calculate the Haven ratio as a function of the Rb/Na ratio. The Haven ratio at 149.6°C increases from…
Order–disorder transitions occurring in the Ag 2 SO 4 –K 2 SO 4 system were investigated by reaction kinetics, thermal analyses, X-ray diffraction, and electrical conductivity techniques. Solid–liquid and solid–solid phase diagrams are reported.The conductivity data in the high temperature phase of the solid resemble…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPicosecond photodissociation of six-coordinate iron(II) porphyrinsDabney White Dixon, Christine Kirmaier, and Dewey HoltenCite this: J. Am. Chem. Soc. 1985, 107, 4, 808–813Publication Date (Print):February 1, 1985Publication History Published online1 May 2002Published inissu…
Nitrooctaethylporphyrins readily undergo nucleophilic aromatic substitution in the presence of HCl or HBr. In the presence of methoxide, nucleophilic addition to give a porphodimethane occurs, followed by autoxidation to the methoxyporphyrin. Unlike the nitrated complexes, the chlorosubstituted porphyrins exhibit redo…
Experiments in which a long vertical, heated wire is surrounded by concentric annuli of a melt and its crystalline solid show that the convection state changes from a stable unicell surrounded by a stationary cylindrical solid–liquid interface, to a complex time-dependent flow surrounded by a rotating, helical solid–l…
We report the feasibility of x-ray scattering studies of freely suspended strands of discotic liquid crystals of triphenylene hexa-n-dodecanoate (HATH) and of hexa-alcoxy derivatives of triphenylene (HET11). With use of a pin and cup configuration, we are able to grow strands, which are stable for days, of diameter >…
Kristallines Silber(III)‐oxid , das bei −20°C längere Zeit beständig ist, wurde durch anodische Oxidation von AgCIO 4 , AgBF 4 oder AfPF 6 (nicht AgNO 3 ) in wäßriger Lösung erhalten. Definiertes Ag 2 O 3 war bisher nicht bekannt. Es interessiert als möglicher Bestandteil der Anoden in Zink/Silberoxid‐Primärzellen. Na…
An undisturbed site under forest cover near Breton, Alberta was chosen to study the characteristics of a typical Gray Luvisol. Smectite and to a lesser extent mica were dominant in the clay fraction of the Bt. This horizon contained higher levels of organic C, pyrophosphate-extractable Fe and Al and dithionite-citrate…
The root growth of an Al sensitive barley (Hordeum vulgare L.) was used to evaluate the influence of surface applied amendments on the properties of an acid subsoil. Soil columns were packed with 10 cm of A horizon over 45 cm of an acidic Bt horizon from a Gilpin silt loam. Prior to planting of the barley the columns…
We present the results of Monte Carlo simulations of the equation of state of hard ellipsoids of revolution with axial ratio's a/b = 3, 2.75, 2, 1.25, 0.8, 0.5, 0.3636 and 0.3333. We identify four distinct phases, viz. isotropic fluid, nematic fluid, ordered solid and plastic solid. In all cases the thermodynamic phas…
High resolution replica materials are routinely used in scanning electron microscopy. A systematic evaluating procedure for replica combinations is proposed which details fourteen points to be recorded. These points include quantitative and qualitative information useful when assessing a replica combination for a part…
In this study, the glass transition temperature is determined from thermal expansion measurements in a series of glass compositions prepared by bulk fusion of a phosphosilicate matrix to which oxides of boron, germanium, or arsenic are added. On a per‐molar basis, addition of boron was observed to be the most effectiv…
Abstract Research relevant to the understanding of polymer–metal adhesion led us to an oxygen Auger (KLL) study on metal oxide surfaces. This was done in order to analyse the ionicity and strength of ‘Lewis sites’ on oxide surfaces grown on metals as compared to their bulk metal oxide counterparts. Following some sugg…
A generalized model of plain woven fabric is proposed, based on a more realistic approximation of yarn bending behavior than that previously used. Peirce's rigid thread model is a special case. Approximate formulae for calculating the ratio of crimp height to thread spacing and weave angle are developed.
The intensity and spectrum of light scattered by a nematic liquid crystal of positive dielectric anisotropy (5CB) in the presence of an ac squarewave electric field have been measured. The results for the twist-bend mode agree well with the theory developed by the Orsay Group and lead to satisfactory values for elasti…
The differences in frictional forces acting between fabrics woven from filament yarns are dependent on the morphology of the fabrics and the rubbing direction. When one fabric is moved across a second stationary fabric and the projecting yarn waves of one of the fabrics is rubbed perpendicular to the yarn axes orienta…
This paper describes the change in the partial discharge (PD) characteristics due to the growth of electrical trees in insulating materials under the application of an AC voltage. An electrical tree consists of branch-like dielectric breakdown paths. Investigation of a number of characteristic PD parameters shows that…
The synthesis of ribbons of a highly conducting, undoped organic polymer by the pyrolysis of 3,4,9,10-perylene-tetracarboxylicdianhydride is described. The conductivity is not decreased upon exposure to selected donor or acceptor dopants, suggesting that the high observed conductivity is not due to a charge-transfer c…
The complex ( C U H A P ~ ~ ) ~ V O ( C ~ O ~ ) ~ ~ ~wHhe~re OC-uH~A/Pe~nC is~ (NH,N~’-NetOhy~le,ne bis(0-hydroxyacetophenone iminato)) copper(II), was synthesized and its crystal structure solved at room temperature. It crystallizes in the orthorhombic system, space group P212121. The lattice constants are a = 20.928…
Abstract If the binary transition metal oxide Co 1‐δ O is exposed to an oxygen potential gradient, a steady state flux of cation vacancies from the high to the low potential and a corresponding flux of cobalt cations in the opposite direction are induced. Thereby, the crystal as a whole moves to the side of the higher…