Materials Literature
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The Profile Analysis technique for neutron powder diffraction patterns has been used to show that the lowest temperature phase of barium titanate is rhombohedral R3m with cell angle α = 89.868 ± 0.004°at 77.4 K. The atomic displacements from the cubic perovskite positions are along [111], and have magnitudes of δ (Ba)…
The Onsager theory for the liquid crystal phase transition of a gas of hard rods is known to be accurate if the rods are long enough. In order to quantify the necessary length, the first correction term (the third virial coefficient) to the Onsager theory is estimated numerically. On the basis of a study of the behavi…
The peel strength of rubber and paint films has been measured over a range of peeling velocities using a dead weight method. At low peel rates the peel force is fairly constant but rises rapidly at higher peeling speeds. Experiments show that the peel strength is a function both of the energy of interfacial bonds whic…
The structure of the ferro electric phase of Triglycine Sulfate has been refined from neutron diffraction data. The hydrogen bonding scheme proposed by Hoshino, Okaya and Pepinsky2 has been confirmed. The short hydrogen bond between glycine II and glycinium III that has been postulated to cause the transition has been…
1. A Brief History. 2. Glass and Glass Fibres. 3. The Products and Manufacturing Processes. The products. An outline of the manufacturing processes. 4. Glass Manufacture. Glass compositions. Selection of raw materials for E glass manufacture. Handling, weighing, and mixing of raw materials into batch. Production of E…
~~~~~~~c~t;;m~+C~+ NAY-+ 3 and D-1-amino-2-propanol dehydrogenase F? D 1 amino-2-propanol + NA&. Each enzyme has been obtained in purified form free of the other; the nature of the reaction catalyzed by the latter dehydrogenase alone and in a coupled system with the former enzyme has been studied. The results provide…
The possibility of creation of a structure of two domains with mutually opposite directions of spontaneous polarization is considered. These domains are divided by a domain wall of metal conductivity with a concentration of free electrons or holes of about 1021 cm-3, the thickness of the conducting layer being about 1…
The method of nuclear microanalysis of stable oxygen isotopes by the reactions was used to investigate the mechanisms of growth, dissolution, and transport associated with oxygen during the formation of relatively thin (≤7000Aå) porous anodic layers on aluminum. The average charge associated with an oxygen ion fixed i…
Abstract The nucleating activity of a large number of nucleating agents for the crystallization of polyolefins is not based on a high surface free energy of the substrate or on epitaxy, or on a minimum particle size just compatible with the thickness of the crystallizing polymer lamellae, or on any persistance of crys…
Structure and properties of disclination lines and disclination points in nematic and cholesteric liquid crystals are reviewed. An equivalence between the directorfield of nematics and electrostatic or magnetostatic fields in two-dimensions is pointed out. Dislination lines can be classified in singular and non-singul…
The electrical conductivity of sintered specimens of CaO ‐ doped CeO 2 [ 0.1 – 16.0 m / o ( mole per cent ) ] was measured over the temperature range 700°–1500°C and from 1 to 10 −22 atm of oxygen. All specimens of CaO ‐ doped CeO 2 exhibited mixed conduction. Two limiting case regions were observed. At low temperatur…
Core binding energies of a number of nitrogen bases and their adducts with BF3 are reported, and interpreted using both ab initio and semi-empirical molecular orbital calculations. The binding energies are found to reflect the change in molecular charge distribution which occurs on formation of the B—N σ bond. The cor…
The system has been studied by a combination of polarization microscopy, using a hot stage, and X-ray diffraction analysis. The sequence of condensed phases occurring at room temperature with increasing concentration of disodium chromoglycate (DSCG) is: (i) a mesophase N; (ii) a mesophase M; (iii) crystalline solid so…
Single-crystal X-ray studies have shown the trishexamethyldisilylamides of scandium(III) and europium(III) to have unusual pyramidal three-co-ordinate structures.
Abstract We have studied the homogeneous hydrogenation of a series of unsaturated polymeric substrates with diimide formed from the thermal decomposition of p ‐toluenesulfonylhydrazide (TSH) at elevated temperatures (110 to 160°C) and in aromatic solvents. At a TSH/olefin ratio of 2.0, homopolymers of butadiene, polyc…
Abstract The structure of spherical droplets of nematic and cholesteric materials floating in an isotropic liquid is experimentally investigated by microscopic observation with polarized light. In nematic droplets either a star configuration or a bipolar configuration have been observed depending on the nature of the…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTProton magnetic resonance investigation of antiferromagnetic oxo-bridged ferric dimers and related high-spin monomeric ferric complexesGerd N. La Mar, G. R. Eaton, R. H. Holm, and F. Ann. WalkerCite this: J. Am. Chem. Soc. 1973, 95, 1, 63–75Publication Date (Print):January 1…
X-Ray photoelectron spectroscopy has been used to study a series of chromium–oxygen compounds. It has been shown that the ionisation energy of the chromium 2p electrons is dependent primarily on the oxidation state of the chromium metal ion, but that small perturbations may be attributed to changes in crystal structur…
Dielectric, piezoelectric and elastic constants have been measured in single domain KNbO3, and electrooptic r-coefficients are estimated. Results allow a thorough verification of Devonshire's theory for the orthorhornbic phase. Good agreement is found for the dielectric and piezoelectric properties whereas fitting the…
The acidity and the concentrations of metal and chloride ions in the solution within a pit were measured for some austenitic stainless steels using an artificial pit activated galvanostatically in 0.5N NaCl solution at 70 C (158 F). The pH and the chloride ion concentration changed in a range of pH -0.13 to 0.80 and 3…