Materials Literature
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Liquid crystals are usually not thought of as ‘simple’ liquids. Nevertheless, a surprising number of features of liquid crystals can be reproduced in computer simulations of very simple model systems, viz. hard ellipsoids of revolution and parallel spherocylinders. In particular, depending on the density and the shape…
A broad superconducting transition with an onset near 30 K is observed for La-Ba-Cu oxides in the measurement of magnetic susceptibility. The superconductivity is of bulk nature and reproducible after several heat cycles.
The iridium(III) anions trans-[IrL2Cl4]–[L = pyridine (py), PEt3, PEt2Ph, PEtPh2, AsEt3, AsMe2Ph, SMe2, or SeMe2] have been prepared and oxidised with chlorine to purple iridium(IV)trans-[IrL2Cl4]. Dark green trans-[IrL2Br4](L = py, PEt3, PMe2Ph, AsEt3, AsMe2Ph, or SMe2) were obtained similarly from trans-[IrL2Br4]– a…
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Potassium dihydrogen phosphate contains phosphate groups connected by hydrogen bonds. Different possible arrangements of the hydrogens result effectively in different orientations of the (H2PO4)− dipoles. Since these have the lowest energy when pointing along the axis of the crystal, there is a tendency toward spontan…
The paper presents a new process for nitrogen alloying austenitic steels beyond solubility limit in a pressurized electroslag remelting furnace using Si3N4 as nitrogen source. With the aid of this process it is possible to attain nitrogen percentages far beyond the solubility limit at atmospheric pressure. These high…
Following upon a preliminary examination of the dihydrogen phosphates of potassium and ammonium by O. Hassel‡ the structure of KH2PO4 has been examined in detail by S. B. Hendricks.§ Laue, rotation and powder photographs were employed in this last investigation, and, in the case of the rotation photographs, a correcti…
Divers OPX provenant de roches de haut grade métamorphique ou de péridotites ont été étudiés par microscopie électronique en transmission analytique. Les structures de défauts observées ont été comparées à celles produites par des déformations expérimentales (fluage à pression atmosphérique et déformation sous pressio…
Symmetrically tetra-substituted phthalocyanines with four quinone or porphyrin units attached have been synthesised and some of their spectroscopic properties are reported.
The calcite-aragonite transition has been experimentally investigated both under hydrostatic conditions and in the presence of deviatoric stresses. The calcite → aragonite experiments at high-pressure have been performed in a Griggs apparatus in the presence of deviatoric stresses whereas the aragonite → calcite exper…
An improved correlation between the binding energy of oxygen core electrons (Eb (Ols)) and the effective charge of the oxygen atom (qo) is proposed: Eb(01s) =4.23-qo +534.1.
Description Fight chapters describe testing procedures suitable for the measurement of dielectric properties of solid insulating materials. They explain why dielectric measurements are made, their specialized uses, and their limitations.
C. Bonnelle, Annu. Rep. Prog. Chem., Sect. C: Phys. Chem., 1987, 84, 201 DOI: 10.1039/PC9878400201
Abstract In the asymmetric epoxidation of homoallylic alcohols, a combination of zirconium tetrapropoxide, dicyclohexyltartramide, and t-butyl hydroperoxide was found to give good enantiomeric selectivities (up to 77% ee) especially for (Z)-homoallylic substrates.
The crystal and magnetic structures of the lamellar FexTiSe 2 (x = 0.25 and 0.48) antiferromagnets have been refined from neutron diffraction powder data at several temperatures ranging from 2 to 300 K. For both compounds, Ti is found to be substituted for 8 % of Fe so that the separation of the two metals is not comp…
Cyril Stanley Smith, Pauline Boucher, The Tiling Patterns of Sebastien Truchet and the Topology of Structural Hierarchy, Leonardo, Vol. 20, No. 4, 20th Anniversary Special Issue: Art of the Future: The Future of Art (1987), pp. 373-385
The diffusion coefficients of hydrogen and deuterium in commercially pure iron deformed and annealed under various conditions have been measured at temperatures between 283 and 318 K by an electrochemical permeation method. The temperature dependence of the diffusion coefficients of hydrogen (DH) and deuterium (DD) is…
The first water-soluble cryptophane (4) has been synthesized in three steps from cryptophane-A (1); (4) has been found to complex chloroform and dichloromethane strongly in D2O, with binding constants in the range 103–104 dm3/mol.
In order to immobilize Cs into pollucite structure, hydrothermal reactions of Cs with amorphous aluminosilicate (siliceous sinter) and with mixtures of low-quartz (silicastone) and Al(OH)3, were performed. In both cases, pollucite was formed in 5-N NaOH solution above 200°C for 10 min. Synthesized pollucite was solid…
Ethylene oxidation over well characterised Ag(111) surfaces has been investigated by temperature-programmed reaction measurements and by differential batch reactor studies at pressures up to 50 Torr. The influence of chlorine predosing on catalytic activity indicates that a chemisorbed atomic oxygen species is respons…