Materials Literature
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The electron-phonon interaction matrix element is examined in a modified tight-binding approximation. It is found that the matrix element is proportional to the bandwidth and therefore very small for an extremely narrow band. Paradoxically, in the usual Bloch tight-binding approximation the same matrix element which i…
Ferroresonance is defined in a way corresponding to the more general expression "jump resonance." An analytical method called the incremental describing-function method is applied to the problem of ferroresonance in power systems for a certain class of problems. In general, the method is applicable when the conditions…
Addition of boron to atmospheric-pressure fuel-rich H2+ N2+ O2 flames seeded with alkali metals results in reductions in concentrations of free alkali metal atoms and in formation of negative boron-containing ions. The following enthalpy changes and equilibrium constants are inferred: Li + HBO2⇌ LiBO2+ H ΔH°0=–21 ± 20…
Dynamical behaviors of the soft mode in displacive-type ferroelectrics such as SrTiO 3 and BaTiO 3 are studied theoretically. (1) It is pointed out from the irreversible thermodynamical view point that the critical slowing-down appears directly through frequency, and not directly through damping as in order-disorder p…
Abstract It is known that liquid CS 2 when subjected to high pressure forms a stable solid polymer. Our studies revealed the existence of two distinct forms designated here A and B. Chemical evidence suggests that type A has the composition CS 2 and contains no free sulphur, while type B does contain free sulphur and…
Abstract not Available.
Abstract Phonon dispersion relations in KCl at 80°K have been determined using inelastic neutron scattering. The measurements have been performed mainly in the symmetry directions [100], [110], and [111], but also at some other points in the reciprocal space. More than one third of the phonons in all branches were als…
Abstract Reduction of uscharidin ( 19 ) with NaBH 4 gave a crystalline product C 29 H 42 O 9 which we formulate as β‐tetrahydro‐uscharidin ( 12 ), it was characterised as a crystalline tri‐O‐acetyl‐derivative 14 . The same compound 12 was obtained from calactin ( 18 ) and calotropin ( 18A ), thus confirming earlier re…
The appearance of “annealing hillocks” on heat treated aluminum films has been previously reported. Thin films of Al, deposited on passivated wafers, were annealed for various lengths of time in the temperature range 200°–500°C. The effects of grain size, alloying and surface passivation on hillock formation, were stu…
Abstract Measurements have been made of the F centre optical absorption function for all twenty alkali halides at seven temperatures between ≈ 5 and 300 °K. The measurements have been fitted with a shape function consisting either of an unsymmetrical Gaussian band or, for the halides of cesium, of three symmetrical Ga…
A study was made of the structural details of thin oxide films formed on the (100), (111), (110), and (311) of nickel. Oxidation temperatures ranged from 400° to 600°C, and the oxide films produced were between 25 and 500Aå thick. An x‐ray technique was utilized to measure the average strain in the films, the mosaic s…
The six-co-ordinated titanium(IV) compounds Ti(acac)2X2, where X = MeO, EtO, CF3CH2O, PriO, BunO, ButO, ½[OCH2CMe2CH2O], and Cl, have been studied in solution by infrared spectroscopy and variable-temperature n.m.r. All these compounds adopt the cis-configuration and undergo intramolecular rearrangement, and conventio…
Magnetic and structural studies on a pair of analogous copper(II) acetate and formate dimers suggest that metal-metal bonding is not important in explaining their antiferromagnetism.
Modest additions of sodium acetate, nitrate, iodide, or benzoate to MgCl 2 test solution boiling at 130°C are found to increase resistance to or inhibit stress corrosion cracking of 18‐8 stainless steel. The critical applied potential in MgCl 2 solution (−0.145v) above which, but not below, cracking occurs is shifted…
A new electric field controlled reflective optical storage effect has been discovered in mixed nematic-cholesteric liquid crystal systems. Ion motion produced by a dc electric field is used to emulsify the initially transparent mixture and give it a milky white appearance. This state remains after the dc signal is rem…
Abstract Polymer crystals are characterized by strong anisotropy of binding forces among units, i.e., the intrachain force constant f is much larger than the interchain force constant g . The anisotropic lattice is reduced to an isotropic one, in which each lattice point represents N * units (segment) along the chain…
The optical absorption in doped direct gap semiconductors in which the conduction band may be considered as a degenerate Fermi system is studied near the Burstein edge. The problem is treated within a simple model by the methods of perturbation theory taking into account the final-state interaction between conduction…
Abstract Modification of the carboxyl groups in hen's egg white lysozyme by the carbodiimide-nucleophile procedure developed in this laboratory has shown that all of the carboxyl groups except glutamic 35 can be modified under normal assay conditions. The presence of the substrate protects the aspartic acid residue 52…
Mössbauer spectroscopic data for a range of substituted alkyl- and aryl-tin(IV) compounds are presented. In presumably isostructural series of these and other compounds, the quadrupole splitting increases in the orders: alkyl ∼ aryl ∼ CHCH2 < C6Cl5∼ C≡CPh < C6F5∼ CF3 < SSnR3 < OSnR3, I < Br < Cl < F, and C6H5 < CHCH2…
The temperature dependences of electrical resistivity and thermal expansion were measured for face-centered cubic Fe 65 (Ni 1- x Mn x ) 35 ternary alloys. The electrical resistivity of ferromagnetic alloys ( x <0.3) decreases with increasing magnetic ordering. In contrast to this, the resistivity of antiferromagnetic…