Materials Literature
按标题、摘要、年份、主题和来源检索公开元数据。结果保留作者、摘要、分类与原始来源链接。
Abstract The influence of water and oxygen concentration on stress corrosion cracking of steels in liquid ammonia. Vapor phase cracking in water‐inhibited ammonia storage spheres is also discussed.
Fluoropolymers have become indispensable materials not only in the chemical industries as the pipe laying, the packing, the gasket etc. of the chemical plants, but also in the electrical industries as the electric line, the cable and so on, as a result of the application of their excellent heat resistance, chemical re…
An investigation is reported in which the thermal resistance of jute and jute-blend fabrics was measured by the double-plate method of BS4745. The relation between thermal resistance and thickness is shown to be linear. The relation between fabric conductivity and fabric packing factor is shown to follow Lee's equatio…
NASA goals for reusable space-based, high-performance orbit transfer vehicle propulsion systems have resulted in a need for oxygen/hydrogen engines which include lightweight, highly reliable, liquid oxygen pumps. The selection of ignition- and burn-resistant materials is a major factor in the design of a compact 75,00…
Abstract
U.v. irradiation of metronidazole (1-hydroxyethyl-2-methyl-5-nitroimidazole) in oxygen-free aqueous solution leads to rearrangement via a labile intermediate to N-(2-hydroxyethyl)-5-methyl-1,2,4-oxadiazole-3-carboxamide. The structure has been verified by crystallographic assignment of a 4-nitrobenzoate derivative.
Pearls have a premium on quality. The quality \ndifferences ate so subtle and discrete that even professionals \nin the pearl trade can make wrong judgements. \nThe value of pearls, on the one hand, is decided on bulk \nby weight and, on the other, by the quality of individual \npearls. Being a bio…
A phase transition between states of a nematic liquid crystal in a spherical drop was detected experimentally and described theoretically. This transition took place between states which differed solely in respect of the symmetry of a topological point defect (hedgehog) at the center of the drop. The transition occurr…
The physical contrast ratios (CRs) of an electrooptic switching element using a pyrimidine type ferroelectric liquid crystal (LC) was investigated. The electrooptic response of the element to the AC square wave voltages was shown to be strongly dependent both on the amplitudes and frequencies of the applied voltages.…
Potentiodynamic polarization techniques were used to determine characteristic pitting potentials for Alloy 800 in chloride and chloride-sulfate media. The effect of chloride concentration in the range of 0.001 to 1 M was investigated. Decreasing chloride concentrations resulted in noble shifts of the critical nucleati…
Abstract X‐ray diffraction, positron annihilation, electron microscopy and bulk density measurements are reported as a function of the degree of acetylation for a linters cotton. Heterogeneous reaction proceeds with a retention of ordered structure in the fibers. Substitution does increase the extent of disorder but i…
m e reactions of the w t a l s a l t s of a-isocyanoacetate e s t e r s with isothiocyanates and isccyanates =re examined.me e f f e c t s of mrliQing the reaction paramstem on t h e altcm of the reaction (Schem?I1 of methyl a-isocyanoacetate ( G I with phew1 isothiocyanate (21 have been studied, thus providing elhawe…
Abstract Copper surfaces were ground or polished to various surface roughnesses and analysed by WDS and EDS. Both K and L photons were analysed at the accelerating voltages 5, 15 and 45 kV. The influence of topography on the K‐peak intensity was negligible, while the L‐peak intensity was rather sensitive to the surfac…
The Frank elastic constant for twist deformation k 22, has been determined as a function of temperature for 5CB and compared with values cited in literature. The results, together with the values of the elastic constants for splay, k 11, and bend, k 33, which have been measured recently by Bradshaw et al. and the valu…
Corrosion control is usually implemented by alloy upgrading or material substitution, environmental modification or providing a protective barrier or sacrificial surface or both. Historically, the coatings approach has been the predominant first choice based on initial economics. Current and emerging coating technolog…
The disproportionation of neutral five-co-ordinate [Au(phen)(CN)2Br](phen = 1,10-phenanthroline) in dimethylformamide (dmf) gives a conducting solution from which two charged species, [Au(phen){(CN)0.92Br0.08}2]Br (1) and [Au(phen)(CN){(CN)0.82Br0.18}]·0.5trans-[Au(CN)2Br2]·0.5Br·phen (2), have been separated and char…
The thermomechanical relationship between mullite and a lithium aluminosilicate (LAS) glass‐ceramic has been studied by a technique of bimaterial dilatometry. The viscoelastic behavior of LAS was found to result in a temperature T rvsl below the glass‐transformation temperature T g at which the interfacial stresses be…
Wet granulation, using lactose as an excipient, is widely used in the pharmceutical industry. The use of micro-crystalline cellulose, as part of the excipient, may offer several advantages. The purpose of this work is to investigate the effect of ingredients and processing variables on granule quality. For these studi…
The two-dimensional degenerate Fermi gas of electrons interacting with phonons is considered. The basic mechanisms of momentum relaxation in such a system, associated with electron-phonon, phonon-phonon and electron-electron collisions, are shown to be qualitatively different from similar mechanisms in an ordinary thr…
EPR of Fe 3+ in distorted tetrahedral sites in single crystals of β-Ga 2 O 3 has been measured for the first time, and the second-order zero-field splitting (ZFS) parameters and principal axes directions were determined. The data for the sixfold coordinated Fe 3+ are in good agreement with results from the literature.…