Materials Literature
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The phase diagram of the system Ga-Se has been determined by the differential thermal analysis (DTA). The main features of the diagram are as follows: (1) the melting point of GaSe is 938±3°C and Ga 2 Se 3 is 1005±3°C. (2) the monotectic transition occurs at 915°C in the lower composition region than 50 at.%Se. (3) th…
Abstract The crystal structure of polyisobutylene was determined by x‐ray analysis. The orthorhombic cell, with a = 6.88 Å, b = 11.91 Å, c (fiber axis) = 18.60 Å (space group: P 2 1 2 1 2 1 − D ), contains two molecular chains each consisting of eight monomeric units in the fiber identity period. The chain conformatio…
The factors which determine the resolution and sensitivity of electron spectrometers are discussed. Various types of instruments commonly used in X-ray or ultraviolet photoelectron spectroscopy are reviewed, mainly from an electron-optical point of view. The influence of fringing fields and preretardation on resolutio…
Abstract Novel aromatic diamines have been prepared which contain an ordered sequence distribution of thermally stable, flexible, or rigid units. The synthesis of these materials involves a nucleophilic displacement reaction in aprotic solvent with, for example, the alkali metal salt of p ‐aminophenol, optionally, the…
Abstract Near infrared absorption and emission spectra due to the transitions 2 T 2 ↔ 2 E of the Cu 2+ ion in cubic ZnS have been measured at 4K. The distinct vibronic sidebands of the absorption spectrum exactly correspond to various critical point energies of TA, TO, and LO lattice modes, whereas the structure of th…
α-Al2O3:Ti3+ (300 ppm) at 10 K shows a broad fluorescence spectrum peaked at 14 380 cm−1 with a progression of small shoulders on the high energy side. At 16 216.1 and 16 178.3 cm−1 are two sharp zero phonon transitions from the Jahn-Teller distorted 2Eg to B3/2 and E1/2, respectively, of the ground term 2T2g. Two Eg…
Summary The clay mineralogy of two red‐black soil toposequences on basic igneous rocks in Kenya has been investigated. Besides some illite and amorphous material kaolinites predominate in the slope soils (ultisols) whereas smectites are the main clay minerals in the soils of the depressions (vertisols). The kaolinites…
This paper presents experimental results on the statistical properties of ac and dc breakdown field strength of compressed SF6. The experiment is performed on four gaps of different electrode area, ranging from 0.2 cm2 to 3000 cm2. Patterns of breakdown characteristics are classified into four categories depending on…
Electron microscopic and powder x-ray diffraction studies of small crystals of the lac repressor protein provide evidence on its molecular shape and subunit structure which in turn suggests a possible mode of repressor-operator interaction. The crystals are probably orthorhombic space group P222(1) with unit cell dime…
Abstract Study of 13 oolite samples from Great Salt Lake, Utah by means of X-ray analysis, staining for aragonite with Feigl's solution, and the use of scanning and petrographic microscopes show that aragonite makes up all or more than 90% of the carbonate mineralogy of the samples. This new evidence, combined with th…
Abstract Samples of bentonite, illite, and kaolinite clays were studied for their Zn fixation properties under various pH levels, alternate wetting and drying conditions, and incubation at moisture saturation. Bentonite and illite fixed significant quantities of Zn under wetting and drying. Fixation was directly relat…
Two-component interpenetrating polymer networks (IPN) of the SIN type (simultaneous interpenetrating networks) were prepared from three different polyurethanes and two epoxies. The linear prepolymers were combined in solution, together with crosslinking agents and catalysts, films cast, and subsequently chain extended…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTBiphenol-A Polycarbonate Immersed in Organic Media. Swelling and Response to StressR. P. Kambour, C. L. Gruner, and E. E. RomagosaCite this: Macromolecules 1974, 7, 2, 248–253Publication Date (Print):March 1, 1974Publication History Published online1 May 2002Published inissu…
Energy spectrum of exciton polaron is studied with the dynamical CPA (coherent potential approximation), which is introduced for inelastic scattering by Einstein phonons at every lattice site. The coherent potential at energy E is determined by the potentials at energies apart from E by integral times the phonon energ…
The critical dynamical behavior of the pseudospin-phonon coupled system has been investigated in connection with the structural phase transition of molecular crystals. Based on Onsager's equation of motion, explicit expressions for three correlation functions, spin-spin correlation, phonon-phonon correlation and spin-…
Diffraction studies have enabled the deformation structure of 1T TaS2to be interpreted in terms of charge density waves arising from a Kohn anomaly. There is good agreement between the observed periodicity of the lattice distortion and the value predicted from a Fermi surface based on recent band structure calculation…
The temperature dependence of the rate of growth of Na 2 B 4 O 7 from its melt was determined between 1° and 192°C of undercooling. The maximum rate of growth was 2000 μm/min at 57°C of undercooling. Analysis of the growth data indicated that growth could occur by a screw dislocation mechanism over the entire range of…
Powders of 300-grade maraging steel have been produced by two different atomizing processes and consolidated by hot isostatic pressing, extrusion, hot rolling, or a combination of these methods. The tensile properties of the PM alloys were equivalent or superior to those of the conventionally cast and forged alloys, b…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSynthesis of closo-1,7-dicarbadodecarbone(12) from nido-2-carbahexaborane(9)Richard R. Rietz and M. Frederick. HawthorneCite this: Inorg. Chem. 1974, 13, 3, 755–756Publication Date (Print):March 1, 1974Publication History Published online1 May 2002Published inissue 1 March 1…
This paper is composed of five sections. Section III analyzes the Butler-type and flat-plate lenses of the accelerating lens system in the scanning electron microscope (SEM) using a field-emission gun. Section IV presents the result of an analysis of some new accelerating lens systems when three anodes are present. Th…