Materials Literature
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Abstract Small angle X‐ray scattering measurements were made on samples of polycarbonate (PC) and poly(methyl methacrylate) (PMMA) containing crazes. A sharp, well pronounced maximum in the scattering intensity was observed in the direction perpendicular to the draw direction. The distribution of scattered intensity a…
This Letter investigates the phonon scattering in Si${\mathrm{O}}_{2}$ glass at frequencies above 100 GHz by phonon spectroscopy with superconducting tunnel junctions. By analyzing the frequencies of the scattered phonons with two independent techniques, evidence is obtained for strong inelastic phonon scattering in g…
This Letter represents a theory of transport in random metal alloys which focuses on certain model-independent features of the electron-phonon dynamics which have been previously neglected. It is found that the adiabatic phonon approximation breaks down in the high-resistivity regime producing an anomalous negative te…
Article Verfeinerung der Kristallstruktur des Silberperchlorats AgClO4 was published on November 1, 1979 in the journal Zeitschrift für Kristallographie - Crystalline Materials (volume 149, issue 1-4).
It has long been known that thin films of cholesteric liquid crystals subject to a shear will exhibit a blue shift in the color that they reflect. In this article a molecular structure that could explain this shift is postulated. Using Mauguin’s continuum model of a cholesteric liquid crystal, the governing electromag…
Abstract Les spectres vibrationnels des phases Na 4 SnO 4 , Na 4 PbO 4 et K 4 SnO 4 ont été étudiés pour la première fois. Ils caractérisent des groupements tétraédriques XO 4 isolés. Les attributions des fréquences IR et Raman ont été effectuées par analyse du groupe facteur. Les constantes de forces, calculées à par…
Abstract Hot stretching experiments for an atactic polystyrene have been performed in the temperature range 125 to 180°C, at various elongation rates and with different times of application of the orienting field. Mechanical properties of the oriented samples, including Young's modulus, yield strain and stress, ultima…
The measurements of magnetostriction and anisotropy of r.f. sputtered amorphous Gd1−xCox thin films are reported. Both were measured in the range of composition x=0.667–0.835 using cantilever-capacitance method. The perpendicular anisotropy Ku and saturation magnetostriction λs reach extremal values in the vicinity of…
L-Fucose dehydrogenase [EC 1.1.1.122] was isolated from a rabbit liver extract and purified about 390-fold with a yield of approximately 13%. The purification procedures included treatment with protamine, ammonium sulfate fractionation, treatment with acid, DE-32 celluose colum chromatography, gel filtration on Sephad…
Abstract Tetrachlorothallates MTlCl 4 (M=K, Rb and NH 4 ) crystallizing in the tetragonal CaWO 4 type were obtained by crystallization from highly concentrated aqueous TlCl 3 solutions containing small amounts of MCI. The structural parameters of NH 4 TlCl 4 were determined from single-crystal data. The indates MInCL…
X‐ray diffraction measurements were used to determine the equilibrium phases for Na 2 O·y(Al 1 ‐ x Fe x ) 2 O 3 _ m in air for values of x from 0.05 to 0.6 and values of y from 2.5 to 9. The β“ ‐alumina structure was the only single phase observed. At 1400°C, the β” single‐phase region extends for 3.5< y < 7.5 a…
The discharge capacity of a porous iron electrode is controlled by either the extent of interparticle neck growth achieved during sintering or the amount of surface area retained following sintering. The mode of capacity control is related to the density of the electrode.
Thermal stability criteria capable of explaining Thoma's observations that bias-induced reversible switching transitions in inhomogeneous thin insulating and semiconducting films occur at a critical value of local power density are developed and analyzed. One model, based on a relation between the temperature and heat…
The aberration theory of diffraction gratings has been studied by means of geometric optics. No restrictions are imposed on the form of the grating surface, the pattern of the grooves in the grating surface, and the position of the object. Furthermore, the image plane is not limited to one normal to the principal ray.…
Abstract Stereoselective syntheses of the two optically active pheromones of ants, (+)-(E)-4,6-dimethyl-4-octen-3-one (manicone) and (+)-(E)-2,4-dimethyl-2-hexenoic acid, and of β-sinensal and (E)-β-farnesene are described in which allylic thiolcarbamates readily derived from allylic alcohols via the [3,3]sigmatropic…
Second order transitions are discussed for compounds of the heavy rare earths and yttrium with cobalt. The calculated Curie temperatures agree well with those observed and an analogy is established between the effect of rare earth additions and of pressure. First order transitions in critical fields and at critical te…
This paper describes an improved method of predicting the breakdown voltage and volt-time characteristic of wood-porcelain combinations. The model accounts for the different voltage waveshapes that stress each element of the combination. The integration method is used to evaluate the breakdown and the time to breakdow…
Experiments are described in which the orientation and curl of fibre segments in some random, parallel, and cross-laid fabrics were examined with a scanning electron microscope (SEM). A technique for the measurement of these parameters that consists in the enlargement of the SEM photomicrographs to obtain traces of fi…
Abstract Wax migrates from the bulk of a rubber article to its surface to form a physical barrier to ozone attack. The extent of migration depends upon the solubility/mobility characteristics of the specific wax under a given set of environmental conditions. Factors which influence migration include time and temperatu…
Abstract Raw materials selection and method of synthesis determine the type of branching in a commercial branched fatty acid. The type of branching plus the isomer distribution, the normal chain/branched chain ratio, the chain length distribution, and the purity of the acid determine the physical properties of commerc…