Materials Literature
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A practical electro-optic page composer has been constructed from single crystal gadolinium molybdate, Gd2(MoO4)3. The characteristic 'ferroelectric-ferroelastic' effect in Gd2(MoO4)3 is based on the existence of bistable states of the optic plane which can be rotated 90° by the application of an electric field E3 or…
A simulation of the development of rolling texture in f.c.c. polycrystals has been performed, assuming that the deformation mechanism is multiple {111} 〈110〉 slip. The predicted crystallite orientation distribution functions for 40% and 80% reduction are in fair agreement with the experimentally determined texture of…
Abstract Tetraphenylporphiniron(II) was synthesized and isolated in a pure state. The iron(II) porphin was in the state of S=2. The spin state of iron(II) porphin varies with the axial ligand field. Oxygeneous axial ligands such as tetrahydrofuran and dioxane gave an intermediate spin state (S=1), while nitrogeneous l…
It is experimentally demonstrated in a new and direct manner that electroluminescence in thin films of ZnS: Tb3+ is excited by the direct impact of hot electrons on the Tb3+ ions. The scheme consists of monitoring as a function of applied voltage across the structure studied-a ZnS: Tb3+, Ta2O5 sandwich-the ratio of fl…
Thermal transition enthalpy changes (ΔHf) were investigated in intact and soluble collagen from a variety of sources and species utilizing differential scanning calorimetry. Results indicated that the ΔHf determinations were not dependent on sample size, method of preparation, or sample purity. The ΔHf values for inta…
The recently reported permanent poling effects in triglycine sulphate (TGS) containing some α-alanine additive is further investigated by pyroeiectric and dielectric measurements. The probable role of an L-alanine molecule in the lattice of TGS is examined in terms of the atomic motions normally required to reverse th…
The Raman spectra of the soft-phonon behavior in the ferroelectric transition in SbSI is studied by means of a new technique in which the phase transition is induced by hydrostatic pressure. The crystal temperature is maintained constant and the ferroelectric transition is created by a linear shift of the Curie temper…
The crystal structure of Bi3TiNbO9, a two-layer member of the Bi4Ti3O12 family, has been refined from x-ray and neutron diffraction data. Bismuth titanium niobate is orthorhombic, space group A21am, with a = 5.431, b = 5,389, c = 25.050 Å, and Z = 4. Distortions from the prototype structure include sizeable shifts alo…
Abstract The flame retardation mechanisms for cellulose treated with systems based on aromatic phosphates and phosphoramides have been investigated through pyrolysis studies on cellulose and related model compounds. Pyrolysis of cellulose treated with phosphates or phosphoramides proceeds through formation of cellulos…
Y2O3 : Yb : Er and Gd2O3 : Yb : Er are efficient phosphors that emit red light when excited by the absorption of ir radiation. A number of processes are important in suppressing the green emission normally seen in erbium-ytterbium double-doped phosphors, and in emphasizing the often weak red emission. These processes…
Simplified structural models for mullite were investigated, and ir frequencies were calculated for the simplest model which gave the theoretical number of ir‐active frequencies compatible with the observed spectrum. This model, which consists of independently vibrating structural units, gives plausible frequency assig…
Beta alumina (Na 2 O·11 Al 2 O 3 ) with addition of MgO, NiO, ZnO, CuO and CaO, respectively, together with Na 2 O are sintered. Ionic conduction of Na + and X-ray diffraction of these samples are investigated. Additions of above divalent ions, except for Ca 2+ , increase the amount of Na + in β-alumina, leading to an…
Abstract The radiation damage of electron irradiated organic compounds (paraffin, tetracene) was investigated in the temperature range 300 - 4 K. The radiation damage was measured by the decrease of diffraction intensities or the contrast of extinction contours. The damage of the crystals at 4 K required considerable…
Variations in the thermal expansion coefficients, elastic moduli, and fracture strengths of Li 2 O‐SiO 2 glass‐ceramics were determined as a function of nucleation treatment and volume fraction of crystals present. Strength enhancement was attributed to a decrease in the mean free path between crystals as crystallizat…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTDimerization of a copper(II)-phthalocyanine dye in carbon tetrachloride and benzeneAlan R. Monahan, James A. Brado, and Allen F. DeLucaCite this: J. Phys. Chem. 1972, 76, 3, 446–449Publication Date (Print):February 1, 1972Publication History Published online1 May 2002Publish…
Mutants of Escherichia coli and Salmonella typhimurium were selected on the basis of their spontaneous leakage of ribonuclease I. The mutants also leaked several other periplasmic enzymes into the medium during active growth but did not leak the intracellular enzymes glucose-6-phosphate dehydrogenase or phosphoglucose…
X-ray diffraction patterns of 14 substances have been studied in non-oriented samples in the smectic modification sA, sC, and sB. In all three modifications a sharp reflexion was found at small angles. At large angles a diffuse reflexion was found in the modifications sA and sC, and a sharp reflexion in the modificati…
In this article we propose a variational approach to the study of nonlinear elastic solids in which magnetization is constant in magnitude. The emphasis is placed upon the application of the different invariances used in modern continuum mechanics: Euclidean invariance, objectivity, and material symmetry. In Part I, a…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCrystal structures of tetratellurium(2+) tetrachloroaluminate and heptachlorodialuminate, Te42+(AlCl4-)2 and Te42+(Al2Cl7-)2Thomas W. Couch, Donald A. Lokken, and John D. CorbettCite this: Inorg. Chem. 1972, 11, 2, 357–362Publication Date (Print):February 1, 1972Publication…
From the Department of Surgery and Department of Biochemistry and Biophysics at the University of California, San Francisco, California 94122