Materials Literature
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EPR spectra at 9.1 and 30 GHz are reported for the iso-electronic ions Gd 3+ and Eu 2+ in glasses of composition 0.50 ZrF 4 , 0.20 BaF 2 , 0.055 AlF 3 , 0.045 LaF 3 and 0.10 NaF or LiF. The spectra are similar to the 'U' spectra familiar in many oxide glasses, indicating very low and disordered site symmetries with a…
The structural phase transition in GeTe has been investigated by neutron diffraction in the temperature range 295-716 K. Accurate positional and thermal parameters have been obtained as a function of temperature both in the rhombohedral hR2 phase(binary analogue of grey arsenic structure A7) and in the cubic CF8 phase…
Abstract The hydrogenation and dehydrogenation of cyclohexene has been studied in temperature-programmed and isothermal modes over oxide-supported Pt surfaces. The ratio of the rates of dehydrogenation: hydrogenation measured experimentally does not appear to correlate with that expected from standard thermodynamic fr…
Abstract A new R-matrix theory of electron-atom and electron-molecule scattering at intermediate energies is described. In this theory both the outer valence electron of the target atom or molecule and the scattered electron are expanded in terms of a continuum R-matrix basis. This enables target eigenstates as well…
A new variant of the usual x-ray standing-wave experiment, scanning the Bragg reflection in energy at normal incidence, is shown to be applicable to metal crystals without special precautions being taken to ensure high crystalline perfection. The structure of the Cu(111)(\ensuremath{\surd}3 \ifmmode\times\else\texttim…
The primary structure of human uromodulin, a 616-amino acid, 85-kilodalton glycoprotein with in vitro immunosuppressive properties, was determined through isolation and characterization of complementary DNA and genomic clones. The amino acid sequence encoded by one of the exons of the uromodulin gene has homology to t…
Nonuniform flux distributions in amorphous toroidal cores can result in anomalous eddy current losses. Amorphous toroidal cores were excited (by a sinusoidal magnetic flux) and the resulting core losses and local flux distributions measured. Though the overall core flux was sinusoidal, the local flux distribution was…
The wear rate of cast iron and the corrosion potential (Ecorr) and current (Icorr) were measured in sulphuric acid in order to study the mechanism of corrosive wear of cast iron. The corrosive wear rate of cast iron was found to reach a maximum at around 35 wt. percent sulphuric acid concentration and increase with lo…
Abstract In this study the apparent rate constant model was used to determine the mechanism of termination and other rate constants for free radical copolymerizations that are chemically controlled with no penultimate effect. The data required were the number average molecular weight and the conversion obtained at var…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPolyiodides of triethylenediamine: single-crystal resonance Raman spectra and x-ray structuresAndre D. Bandrauk, K. D. Truong, C. Carlone, and A. W. HansonCite this: J. Phys. Chem. 1987, 91, 8, 2063–2069Publication Date (Print):April 1, 1987Publication History Published onli…
Abstract The isotypic compounds SrPt 4 P 6 , SrPt 4 As 6 and BaPt 4 As 6 were found to crystallize with a Pyrite-type derivative structure (monoclinic, C2/c, Z = 4) in which one Sr or Ba atom per formula unit occupies the position of a P 2 or As 2 pair. BaPt 2 P 3 forms another Pyrite-type related structure (monoclini…
Reduced (4-O-methyl-D-glucurono)-D-xylan and nine methylglycosides related to this polysacharide were studied by dynamic and isothermal thermogravimetry. It could be stated from the results that the thermal stability of saccharides is increasing with increasing number of pyranose units. The models related to (4-O-meth…
Formation of fission gas bubbles heretofore has not been observed in uranium-aluminide fuels. Recent irradiations to record high burnups offered a possibility to determine the onset of fission gas bubble formation in this type of fuel. Present experimental evidence suggests that UAl2, UAl3, and UAl4 do not form fissio…
Abstract The activation energies for the racemization of the optically active diaryl selenoxides were estimated by the use of the 77Se NMR spectra of the diastereomeric diaryl selenoxides.
Abstract Successful new thermo‐crosslinking reactions of copolymers of various phenyl methacrylates by use of polyfunctional epoxy compounds were carried out in the film state at 100–150°C in presence of quaternary ammonium salts, quaternary phosphonium salts, tert ‐amines, or the crown ether dicyclohexyl‐18‐crown‐6/p…
Abstract Polymerization conditions of di‐ t ‐butyl fumarate and di‐trimethylsilyl fumarate were studied in detail. They cannot be polymerized by either anionic or coordination initiators, but radical and radiation polymerizations are successful. Characterization of poly(di‐ t ‐butyl fumarate), obtained thereby, with 1…
Mark E. Krejci, Rex L. Lowe, The Seasonal Occurrence of Macroscopic Colonies of Meridion circulare (Bacillariophyceae) in a Spring-Fed Brook, Transactions of the American Microscopical Society, Vol. 106, No. 2 (Apr., 1987), pp. 173-178
In a series of studies on the wettability of textile assemblies, apparent contact angles (ϕ) of wax-coated monofilament nylon and polyester mesh screens to water were measured to investigate the effect of the woven structure on the repellency of textiles. Expressions for the liquid-solid and liquid-air interfaces per…
As a model for a poly(methyl methacrylate ) chain which contains a head-to-head unit, the thermal degradation of tetramethyl 2,4,5,7-tetramethyloctane-2,4,5,7-tetracarboxylate has been studied. The meso compound degraded at 210º to give seven products which have been characterized by spectroscopic techniques and synth…
Measurements of the proton spin-lattice relaxation rate, ${T}_{1}^{\mathrm{\ensuremath{-}}1}$, reveal that the organic insulator copper phthalocyanine Cu(PC) is a highly one-dimensional Heisenberg system. ${T}_{1}^{\mathrm{\ensuremath{-}}1}$ diverges as ${\ensuremath{\omega}}^{\mathrm{\ensuremath{-}}1/2}$ down to 11.4…