Materials Literature
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Defects that produce strong local field enhancement are discussed. They are especially harmful because they do not produce partial discharges detectable in usual factory control tests. Typical examples for such defects are electrode protrusions, floating conducting particles, and the tips of electrical trees. Charge i…
Abstract CdS sols stabilized by sodium hexametaphosphate or poly‐phosphate‐15 were fractionated in a column of sephacryl gel and the fractions investigated by electron microscopy and spectrophotometrically. A linear relationship between the logarithm of the particle size and the elution time was observed. The method m…
Abstract Quantitative analysis by X-ray powder diffraction (XRD) pro-edures is difficult even for simple, well-characterized solid phases. The intrinsic chemical variability of minerals adds a measure of uncertainty to results, and sample-to-sample variations in preferred orientation, commonly encountered with micas a…
Two methods are described for interfacing the finite-element method, used to calculate the electric field structure for a known charge distribution, with the method of characteristics, used to calculate the charge distribution for a known electric field structure, so as to obtain self-consistent descriptions of electr…
To demonstrate the generality of the chevron structure in ferroelectric liquid crystal (FLC) cells, an optical micrograph is presented, which shows a series of defect lines clearly indicating this structure. The generality is understood as a direct manifestation of the smectic layer undulation playing an important rol…
The three-dimensional structure of omega-amino acid:pyruvate aminotransferase from Pseudomonas sp. F-126, an isologous alpha 4 tetramer containing pyridoxal 5'-phosphate (PLP) as a cofactor, has been determined at 2.0 A resolution. The diffraction data were collected with a newly developed Weissenberg camera with a Fu…
The use of Pt–Rh-based three-way catalysts for automotive exhaust-gas control stimulated us to study various Pt–Rh alloy surfaces: well defined single-crystal surfaces and SiO2-supported catalysts. For the sake of comparison data were also obtained for pure Pt and Rh single-crystal surfaces and catalysts. The surface…
Measurements and analysis of contaminant samples from a nuclear power station which has suffered flashovers due to wind-swept salt spray are presented. The results of a program of laboratory tests on artificially contaminated porcelain station insulators, with and without a room temperature vulcanized (RTV) silicone r…
Spin-coupled theory has been applied to the π electrons of the heteroaromatic molecules borazine and boroxine. Benzene is also reconsidered with more elaborate calculations than were used in previous work. The spin-coupled description of benzene, with semi-localized orbitals, is the same as that found previously. The…
A comprehensive investigation was carried out to explore the micro-mechanisms associated with the evolution of deformation microstructure and texture in Ni-Fe alloys during rolling. X-ray diffraction, electron back-scatter diffraction (EBSD) and Mössbauer spectroscopy as well as simulation methods involving crystal pl…
Monolayer assemblies of several phthalocyanine derivatives, e.g. copper tetrakis(n-butoxycarbonyl)phthalocyanine, showing highly anisotropic absorption spectra have been obtained.
Abstract
Rapidly solidified phases in Al–Cu–M ternary alloys ranging from 15 to 20 at%Cu and 10 to 20%M were found to change, with the group number of transition metal M, in the sequence of an amorphous phase for Y, La, Ti, Hf or V, followed by an icosahedral (I) phase for Cr, Mn, Fe, Ru or Os, a decagonal (D) phase for Co or…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCentrosymmetric crystals as host matrices for second-order optical nonlinear effectsI. Weissbuch, M. Lahav, L. Leiserowitz, G. R. Meredith, and H. VanherzeeleCite this: Chem. Mater. 1989, 1, 1, 114–118Publication Date (Print):January 1, 1989Publication History Published onli…
Here we discuss the statistical mechanics of polydisperse liquid crystal systems. Three different kinds of liquid crystal systems are treated: nematic order in thermotropic Maier-Saupe-like systems and in lyotropic Onsager-like rod systems, and smectic order in a perfectly aligned hard rod fluid. In the first two case…
The photophysical properties of a new series of tripyrroledimethine-derived ‘expanded porphyrins’(‘texaphyrins’) are reported; these compounds show strong low energy optical absorptions in the 730–770 nm spectral range as well as a high triplet quantum yield, and act as efficient photosensitizers for the production of…
A principal goal of the field of conducting polymers is to strive for advances in materials quality that will enable the exploration of the intrinsic electrical properties. In this context, we summarize the requirements for achieving high performance conducting polymers with electrical conductivities greater than that…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSynthesis of substituted pyrroles via zirconocene complexes of iminesStephen L. Buchwald, M. Woods Wannamaker, and Brett T. WatsonCite this: J. Am. Chem. Soc. 1989, 111, 2, 776–777Publication Date (Print):January 1, 1989Publication History Published online1 May 2002Published…
Polypyrrole (PPy) and poly-N-methylpyrrole (PMPy) films have been prepared on electrodes in NaCl, polystyrenesulphonate (PSS), and dodecylsulphate (ROSO3–) electrolytes. The redox-switching of these coatings has been studied, mainly in NaCl electrolytes. At various electrode potentials the coated electrodes were withd…
All articles of this category 2-Oxo-5,6-dihydro-1,3-dithiolo[4,5- b ][1,4]dithiin ( 4 ) was prepared in four steps from cheap starting materials in high overall yield. Coupling of 4 with trimethyl phosphite in toluene gave bis(ethylenedithio)tetrathiafulvalene ( 5 ; BEDT-TTF; 2,2′-bi-5,6-dihydro-1,3-dithiolo[4.5- b ][…