Materials Literature
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ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCarbon-13 and deuterium NMR spectroscopy of high-spin manganese(III) porphyrin halide and pyridine complexesHarold M. Goff and Andrew P. HansenCite this: Inorg. Chem. 1984, 23, 3, 321–326Publication Date (Print):February 1, 1984Publication History Published online1 May 2002P…
Abstract Aus KSn bzw. RbSn entstehen durch direkte Oxydation K 2 Sn 2 O 3 bzw. Rb 2 Sn 2 O 3 bei 320°C bzw. 410°C die bislang unbekannten „Tieftemperaturformen”︁ (a = 8,4100(8)Å bzw. a = 8,6368(8)Å), isotyp mit kubischem K 2 Pb 2 O 3 . Bei höherer Temperatur (510 bzw. 520°C) entstehen die bekannten Hochtemperaturforme…
The electrical conductivity of Li‐doped Cr 2 O 3 was investigated as a function of PO 2 , temperature, and dopant content. Results show that the electrical conductivity remains almost unchanged with decreasing P O 2 in the high‐P O 2 region but decreases rapidly at low P O 2 . A second phase was found in samples which…
By means of high-angle double-crystal X-ray diffractometry (HADOX), lattice constant measurements with a relative accuracy of better than one part in 106 have been made of SrTiO3 single crystals grown by the Verneuil method. An analysis of the temperature dependence of the lattice constants below the transition temper…
Abstract The dielectric properties of miscible blends of poly(vinyl chloride) (PVC) and poly(α‐methyl‐α‐n‐propy‐β‐propiolae‐tone) (PMPPL) have been investigated at different temperatures above and below T g . The results were analyzed using the Cole‐Cole representation and lead to the conclusion that this mixture does…
A general theory of a vibrating magnetometer pick-up system employing extended circular coils is outlined in the point magnetic dipole approximation. Systems based upon cylindrical and toroidal coils are discussed in more detail with some attention focused on the ability of the systems to measure simultaneously all co…
Mechanical and dielectric strengths were measured for BaTiO 3 , ceramics at room temperature. The results were evaluated in terms of Weibull statistics, and a clear analogy between the mechanical and dielectric strength distributions was found.
Abstract A green smectitic mineral from Jordan with 16% Cr 2 O 3 (almost 22% on an ignited basis) has been shown by chemical, X-ray, electronoptical, electron microprobe, infrared and thermoanalytical evidence to be an iron-free volkonskoite of composition: 1·06 M + (Si 7·39 Al 0·61 )(Cr 2·20 Mg 2·52 )O 20 (OH) 4 . Th…
Abstract The procedure for synthesizing proto-imogolite (an acid-soluble hydroxy-aluminium orthosilicate complex) and imogolite (a tubular aluminosilicate mineral) was used to produce ferruginous aluminosilicates over a range of Al/Fe ratios to determine whether Fe 3+ can be incorporated in the imogolite structure. An…
When describing clay minerals of natural origin one often has to take into account the possibility that they contain other phases, e.g. iron oxides and hydroxides which may form a ‘coating’ on the clay mineral itself or occur as physically inseparable ultra-fine particles. These iron oxyhydroxides are sometimes diffic…
Abstract A new and simple enzymatic assay for measuring D-mannose in serum is described. Endogenous glucose is eliminated from serum by use of glucose oxidase (EC 1.1.3.4) and catalase (EC 1.11.1.6). D-Mannose concentration is calculated from the increase in NADH formation after mannosephosphate isomerase (EC 5.3.1.8)…
Existence of the ferroelectric phase in AgNbl-xTaxO3 solid solutions was confirmed. Temperature of the ferroelectric phase transition decreases from 348K for AgNbO3 to 140K for AgNb0.4Ta0.6O3 with increasing Ta concentration. Investigations of spontaneous polarization Ps, total pyroelectric coefficient pt and dielectr…
The pressure-temperature phase diagram of tetramethylammonium tetrachloromanganate {N(CH 3 ) 4 } 2 MnCl 4 was determined by dielectric measurements. As pressure increases the normal phase (I) to incommensurate phase (II) transition temperature (19.7°C at 0 MPa) increases. The region of commensurate phase with c =2 c 0…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTKinetics and mechanism of the reaction between phenyl isocyanate and alcohols in benzene mediumS. Sivakamasundari and R. GanesanCite this: J. Org. Chem. 1984, 49, 4, 720–722Publication Date (Print):February 1, 1984Publication History Published online1 May 2002Published iniss…
Citrate transport in Salmonella typhimurium involves inducible periplasmic components. Two forms of a tricarboxylate-binding protein, C1 and C2, were isolated, in high yield, from the periplasm of a cyclic AMP phosphodiesterase mutant. These immunologically cross-reactive Mr = 29,000 proteins were crystallized using a…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTDegradation of chain molecules. 2. Thermodynamically induced shear degradation of dissolved polystyreneM. Ballauff and B. A. WolfCite this: Macromolecules 1984, 17, 2, 209–216Publication Date (Print):February 1, 1984Publication History Published online1 May 2002Published ini…
Abstract Water‐ground Phlogopite micas were classified into narrow particle‐size distributions containing flakes with well‐defined diameters and thicknesses in order to evaluate the influence of particle size and flake aspect ratio on the mechanical properties of mica‐filled polypropylenes, For the purposes of compari…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTRegioselective functionalization of heterocyclic rings: synthesis and reactions of 1-methyl-2-(trimethylsiloxy)pyrrole and 2-(trimethylsiloxy)thiopheneMariella Fiorenza, Gianna Reginato, Alfredo Ricci, Maurizio Taddei, and Pasquale DembechCite this: J. Org. Chem. 1984, 49, 3…
Recently, interlayer exchange-coupling constants in solids of compounds $[\mathrm{N}{\mathrm{H}}_{3}{(\mathrm{C}{\mathrm{H}}_{2})}_{n}\mathrm{N}{\mathrm{H}}_{3}]\mathrm{Cu}{\mathrm{Br}}_{4}$, with $n=3 \mathrm{and} 4$, have been measured by Drumheller et al. Following our earlier theoretical analysis of such compounds…
The temperature dependence of the soliton density ${n}_{s}$ derived from the dielectric data in ${\mathrm{Rb}}_{2}$Zn${\mathrm{Cl}}_{4}$ is compared with the one obtained from nuclear-magnetic-resonance measurements and x-ray scattering data. The finite value of ${n}_{s}$ at the "lock-in" transition ${T}_{c}$ and the…