Materials Literature
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Abstract In this paper a method is described for the numerical evaluation of phonon widths and shifts due to three‐phonon processes in an anharmonic crystal. With this method the δ‐function and principal value restrictions on the frequencies of the phonons participating in the three‐phonon processes do not have to be…
Abstract Sorgfältig gereinigte Lactone polymerisieren mit anionischen Initiatoren (metallisches Natrium, Naphthalin‐Natrium, Aluminiumalkyle) schon bei Zimmertemperatur zu hochmolekularen Polyestern (M̄ bis 100 000 und höher). Besonders wirksam sind Aluminiumalkyl/Wasser‐Systeme. Bei der Polymerisation des β‐Propiolac…
Abstract By polymerizing phenyl or n ‐butyl isocyanate in various solvents in the presence of anionic catalysts such as lithium or sodium alkyls, crystalline polymers were obtained. For both polymers, the I.R. spectra, the X‐ray diffraction spectra and other physical properties are reported. The possible structures of…
Activation of orthophosphates of the type with copper gives an efficient phosphor in some cases. The brightest phosphors found are and , with an emission peak (with 2537Aå excitation) at 4150 and 4600Aå, respectively. The properties of orthophosphates of the type with two kinds of alkali earth or alkali metal ions, re…
D. J. Greenland, R. H. Laby and J. P. Quirk, Trans. Faraday Soc., 1962, 58, 829 DOI: 10.1039/TF9625800829
Abstract Biotite samples were treated with NaCl‐NaBPh 4 solutions and various methods of separating the precipitated K from the resulting mixture were evaluated. As a result, a boiling NH 4 Cl solution method was adopted for K extraction experiments with small samples and a foaming method was used in the preparation o…
Oxygen-18 exchange between gaseous oxygen and cadmium oxide crystals has been studied in the temperature range 630° to 855°C. Since isotope equilibrium is not instantaneously established at the crystal surface an appropriate solution for this particular diffusion problem has been given. In this way it is possible to e…
A method for calculating the anodic polarization curves of binary alloys from those of their components is presented. Heterogeneous alloys can be treated as simple galvanic couples, but homogeneous alloys are subject to a modification of Tammann's concept of surface enrichment. Potentiostatic anodic polarization curve…
Abstract Die Herstellung hochmolekularer amorpher Äthylen/Propylen‐Copolymerisate (Äthylen/Propylen‐Kautschuk = APK) mit Z IEGLER mischkatalysatoren aus Vanadiumoxychlorid und Äthylaluminiumdichlorid bzw. Äthylaluminiumsesquichlorid wird beschrieben. Ein frisch hergestellter Mischkatalysator hat eine sehr hohe Aktivit…
Abstract Both the glass transition temperature and the melting point of poly(vinyl chloride have been found to increase as the temperature at which the ample is polymerized is decreased). The glass transition temperature changes from about 70°C. for polymer prepared at 125°C. to about 100°C. for polymer prepared at −8…
The tensile behavior of sapphire whiskers was measured at temperatures ranging from 25–2030°C. At room temperature, the tensile strength of the whiskers is size dependent and varies from several hundred thousand psi to 1 500 000 psi. With increasing temperature the strength decreases and becomes less size dependent. T…
A synthetic crystal of mullre, 2A120 a . SiO 2, was studied by X-ray diffraction methods. The structure was found to be describable as the result of the following changes imposed upon the structure of sillmanre: re-distribution of silicon and aluminium of tetrahedral coordination into a random way over the same set of…
The elastic moduli of cadmium telluride at 25°C have been determined by measurement of ultrasonic wave velocities in the frequency range 40–300 Mc/sec. Preparation of the crystal specimens is described, and factors affecting the accuracy of results are considered. The question of possible piezoelectric stiffening and…
Durch Reduktion von Gemischen aus Platinmetallpulver und pulverförmigen Oxiden unedler Metalle mit Wasserstoff bzw. Ammoniak zwischen 900°C und 1200°C wurden folgende intermetallische Phasen erhalten: Pt3Al, Pt13Al3, Pt3Sc, Pt5Y, Pt5La; Pt15Be, Pt3Mg, Pt7Mg, Pt2Ca, Pt7Ca2, Pt5Ca, Pt2Sr, Pt3Sr, Pt5Sr; Pt7Li und Pt3Cr.…
D. C. Abbott, Analyst, 1962, 87, 286 DOI: 10.1039/AN9628700286
A high‐temperature oxide electrolyte galvanic cell of the type , , O 2 is described. Experimental data for reaction of oxygen with hydrogen‐water and methane‐water mixtures are given. Open‐circuit voltages for the hydrogen‐oxygen reaction are close to theoretical, and current‐voltage curves show that the output of the…
Recent experiments on the dc ionic conductivity of NaCl crystals doped with divalent cation impurities led to a re-evaluation of some of the basic constants for defect formation and motion in these crystals. The key parameter is the energy of motion εm of a cation vacancy. This parameter has been determined from the t…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTORDERING OF THE OCTAHEDRALLY COÖRDINATED CATION POSITION IN THE PEROVSKITE STRUCTUREFrancis Galasso and Wilda DarbyCite this: J. Phys. Chem. 1962, 66, 1, 131–132Publication Date (Print):January 1, 1962Publication History Published online1 May 2002Published inissue 1 January…
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The nature of the minimum energy configuration of jogs of various lengths in dislocations in face-centred cubic metals is studied. It is concluded that long jogs of various types are partially dissociated into intrinsic stacking-fault ribbons on close-packed planes, and that elementary jogs in dislocations in a range…