Materials Literature
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A review is given on the structural phase transition of hexagonal type BaTiO3 at 222 K and on the ferroelectric · ferroelastic phase transition at ∼ 70 K. X-ray studies and Raman studies have disclosed that an E2u phonon mode condenses below 222 K where crystal changes from hexagonal P63/mmc to orthorhombic C2221-D5 2…
A generalized approach based on numerical evaluation of the Fourier coefficients is used to determine the performance of three-phase phase-controlled thyrode AC voltage controllers. Balanced resistive and inductive loads of different power factors are considered. Various electrical properties are computed and compared…
We have investigated orientational behaviors of nematic liquid crystals of phenylcyclohexane derivatives and their solutions of Ti(OBu)4—AlEt3 catalyst under a magnetic field by means of optical transmission measurements. Magnetic field required to achieve an ultimate orientation of the liquid crystal is found to be 1…
Abstract The structures of conglomerate crystals, p-chlorobenzenesulfonic acid salt of l-alanine, p-toluenesulfonic acid salt of l-serine, and benzenesulfonic acid salt of l-leucine, were determined by X-ray analysis. The crystals are built up of repeating units consisting of two amine components and two acid componen…
The field dependence of magnetization, which is a serious handicap for a straightforward application of magnetizable materials in the process of basic field correction, is discussed. The principles for compensation of this dependence by an appropriate choice of magnetic material, the operating point on the hysteresis…
Abstract Thermosetting resins composed of triarylmethane structure were prepared by heating a mixture of a polycyclic aromatic compound and an aromatic aldehyde in the presence of an acid catalyst. The resin prepared from the mixture of pyrene and terephthalaldehyde exhibited scarcely any weight loss up to 530 °C unde…
Abstract Basic aluminium chloride gels and the crystalline salt AlCl 3 · 2 Al(OH) 3 · 6 H 2 O are thermally decomposed to an amorphous product in a first step at low temperatures. If the reaction gas is rapidly removed the amorphous decomposition product directly transforms to corundum at increased temperature. Starti…
An ultrastructural study of the embryonic and larval shell of Anodonta cygnea was carried out by light, polarization, and scanning electron microscopy, and X-ray diffraction analysis. A thin outer layer (cuticle), composed of β-keratin fibrils organized in parallel rows and enveloped by chitin material, was observed.…
The presence of degenerate graphite in heavy section ductile iron causes a significant decrease in its mechanical properties. In this paper, two types of degenerate graphite are classified: large non-spheroidal graphite and small chunky graphite. The formation processes of degenerate graphite have been investigated by…
We report experimental results on the kinetics of the electron-beam-induced reduction of WO3 by in situ high-resolution electron microscopy. Electron-beam irradiation of WO3 results in complete reduction to W. The process is surface-initiated through desorption of oxygen from the crystal surface, and the subsequent gr…
Abstract 10-Methylacridinium ion (AcrH+) is reduced efficiently by fatty acids (RCOOH) in the presence of a base in acetonitrile to yield 9-alkyl-10-methylacridan selectively under irradiation with visible light via photoinduced electron transfer from RCOO− to the singlet excited state of AcrH+.
Abstract Polyesterifications of adipic acid with ethylene glycol, 1,4‐butanediol, and 1,6‐hexanediol in the absence and presence of the foreign acid ( p ‐toluene sulfonic acid) as catalyst were carried out under constant reaction temperatures of 140–180°C (rather than at constant oil‐bath temperatures) and at ratios o…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSynthesis and crystal structure of bis[undecafluorodixenon(1+)] hexafluoronickelate(2-)Adolf Jesih, Karel Lutar, Ivan Leban, and Boris ZemvaCite this: Inorg. Chem. 1989, 28, 15, 2911–2914Publication Date (Print):July 1, 1989Publication History Published online1 May 2002Publi…
A method to determine the magnetizing characteristic of three-phase transformers is described. In the analysis, the measured currents and voltages generated during transformer switching are used. The magnetizing characteristic is calculated from the primary currents, rather than the current through the delta winding.&…
Cable-fed five-legged core grounded-wye-to-grounded-wye transformers can cause excessively high voltages in a power system. A typical per-phase equivalent does not adequately represent a five-legged core transformer for the steady-state or transient analyses required in investigating overvoltages. A three-phase equiva…
Absorption, emission, and excitation spectra of Ce-doped Gd2 SiO5 have been measured. The emission spectrum is decomposed into two Gaussian bands corresponding to the transitions from Ce3+ 5d 2 T2 to two 4f levels of 2 F7/2 and 2 F5/2 . It is found that the energy difference between ground 2 F5/2 and 2 F7/2 levels var…
The effect of adding molybdate ions to a chloride-containing solution has been studied at different stages of pit growth under potentiostatic control. There is a critical size below which already existing pits are passivated after molybdate addition. Molybdate thus appears to be more effective in reducing pit growth w…
Previous work on Ba2TiGe2O8 crystals has shown an unusual low-temperature (∼ 223 K on cooling, ∼ 273 K on heating) phase transition. Precession x-ray photographs on Ba2TiGe2O8 single crystals show an incommensurate modulation along b*, and, for the first time, also along a*. Single crystal intensity data confirm the a…
The defect structure model in the wustite phase is considered involving the 4:l cluster as a basic defect structure unit. Interactions between defects are considered in terms of the Debye‐Hückel theory for strong electrolytes. It has been shown that the available data on wustite nonstoichiometry fit well the 4:l clust…
TeGeSnAu thin films were studied for phase change type rewritable optical disk material. Addition of Au to TeGeSn thin film shortened crystallization time. The crystallization time of Te 60 Ge 4 Sn 11 Au 25 thin film was about 0.3 µs and was less than one 100th of that of Te 80 Ge 5 Sn 15 thin film. Formation of a sim…