Materials Literature
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The double decomposition of hafnium and titanium tetrakis tertiary amyloxides was used to produce high‐purity stoichiometric submicron HfTiO 4 powders. The particle size range was 50 to 400 Å. X‐ray diffraction of a 1:1 mixture, as‐prepared and heated to ∼750°C, indicated that the material is 95% orthorhombic HfTiO 4…
The preparation, microstructure, and properties of BaZrS 3 ceramics are described. The compound was prepared by heating either an equimolar mixture of BaS and ZrS 2 or BaZrO 3 alone in CS 2 gas. The reaction of the BaZrO 3 −CS 2 system was extremely rapid, as would be expected in an autocatalytic reaction caused by ve…
Epitaxial AlAs was grown on GaAs substrates, and polycrystalline AlAs films were deposited on quartz. The visible optical absorption edge indicated that the direct band gap was 3.5 eV while the indirect gap was 2.2 eV. Infrared interference fringes were measured and the high-frequency dielectric constant was determine…
Abstract Energy loss of the electron beam in the specimen affects the electron microscopical resolution, owing to chromatic aberration, and causes radiation damage by ionisation, heating and direct ejection of atoms. Measurements recently made of the energy loss in carbonaceous specimens confirm that the effect on ima…
This paper considers electrical discharge mechanisms as they occur across relatively dry zones on wet contaminated insulator surfaces. A mathematical model was assumed with constant surface resistivity, and constants were evaluated from experimental results obtained using a simple cylindrical geometry with a dry zone,…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTFurther studies of the thermal decomposition of europium hexacyanoferrate(III) and ammonium europium hexacyanoferrate(II)Patrick K. Gallagher and Betty PrescottCite this: Inorg. Chem. 1970, 9, 11, 2510–2512Publication Date (Print):November 1, 1970Publication History Publishe…
series gives 146541.56. The latter has been adopted though no explanation of the discrepancy has been found.
Abstract Potassium release rates from micas varying widely in type and composition were measured. A sodium tetraphenylboron solution was used as the extracting agent. Muscovites were found to be two orders of magnitude more stable than a naturally occurring phlogopite and biotite. Synthetic fluorphlogopite was as stab…
Studies were carried out to determine the feasibility of weaving triaxial fabrics (Doweave) in tight, low-porosity con figurations, and to investigate the stability and isotropy of triaxially woven fabrics. Detailed analyses of yarn motions required in triaxial weaving cycles disclosed no fundamental problems to preve…
The band motion (tunneling) of small polarons in thermally activated energy levels of molecules is postulated to be the conduction mechanism is some organic and biological semiconductors. The compensation law is derived from this model. The characteristic temperature is shown to be related to the Debye temperature.
Abstract Elektronenmikroskopische Präparate verändern sich während ihrer Untersuchung im Mikroskop durch Kontamination, Objektabbau und unmittelbare Strahlenschädigung. Diese Vorgänge wurden im Elektronenmikroskop bisher nur integral untersucht, etwa durch Bestimmung der zeitlichen Änderung der Massendicke des Präpara…
The recent sequence determination of histone F2b has allowed a detailed nuclear magnetic resonance study of the conformational changes and interactions of this protein with (a) increasing ionic strength, (b) increasing concentration and (c) change of pH. In all cases it has been found that a specific region of the pol…
Abstract Pyridoxal kinase catalyzes the formation of pyridoxal phosphate, a coenzyme required for many metabolic reactions. A 2000-fold purification of the enzyme from bovine brain has been achieved by a combination of ammonium sulfate fractionation, DEAE-cellulose chromatography, gel filtration, and affinity chromato…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTFixed-Bed Adsorption Kinetics with Pore Diffusion ControlR. S. Cooper and D. A. LibermanCite this: Ind. Eng. Chem. Fundamen. 1970, 9, 4, 620–623Publication Date (Print):November 1, 1970Publication History Published online1 May 2002Published inissue 1 November 1970https://pub…
The effect of free conducting particles (FCPs) on the voltage-insulating performance of a short length of transmission line was quantitatively studied over the pressure range 0 to 300 psig for nitrogen and 0 to 125 psig for SF6. The FCPs were selected aluminum filings deliberately inserted into the concentric cylindri…
The magnetic susceptibility of the ${({\mathrm{V}}_{1\ensuremath{-}x}{\mathrm{Cr}}_{x})}_{2}{\mathrm{O}}_{3}$ system ($0\ensuremath{\le}x\ensuremath{\le}1$) has been studied over the temperature range 4.2-1000 \ifmmode^\circ\else\textdegree\fi{}K. For $0\ensuremath{\le}x<0.035$, the susceptibility data clearly indi…
Abstract A diffusional model was established to study the kinetics of thermally‐induced solid state polycondensation of poly(ethylene terephthalate). Diffusion through solid polymer is the rate controlling step when temperature is higher than 210°C and particle size is no smaller than 100 mesh. The activation energy i…
Abstract Es wird über erste Versuche berichtet, elektronenmikroskopische Hellfeldaufnahmen schwacher Phasenobjekte nachträglich durch Anwendung von Rekonstruktionsmethoden rechnerisch zu korrigieren. Der interessierende Bildbereich wird von einem automatischen Photometer abgetastet und in digitaler Form repräsentiert.…
The angular distribution of ${\mathrm{O}}^{\ensuremath{-}}$ produced by electron bombardment of ${\mathrm{O}}_{2}$ has been measured in the electron energy range 5.75-8.40 eV. The results show a strong energy dependence and are consistent with the theory of O'Malley and Taylor if the final $\mathrm{O}_{2}^{}{}_{}{}^{\…
Thin parylene films have been prepared and are available in thicknesses to 0.025 μ. The parylene polymers are shown to be extremely uniform in thickness, have good gas barrier properties, and are relatively nonabsorbing throughout the entire soft x-ray region. Comparisons are made with commercially available Mylar, po…