Materials Literature
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In diffusion-controlled sorptive processes, Fick's second equation can be solved analytically only for special functional forms of an immobilization isotherm. The dissimilarity in the formal appearance of attainable solutions hides common features of physical behaviour. The rate processes can, however, be broadly char…
The structure change of tantalum on heating in air and oxygen was followed by X-ray diffraction. Numerous forms of Ta oxides have been identified. Ta-(O) (solid solution), TaO y , TaO z , δ-form and β-Ta 2 O 5 are formed in air at either atmospheric or reduced pressure. The nitrogen in the air is important for high te…
Stoichiometric crystals of and were grown by slowly cooling solutions of the polycrystalline apatites in fused or . While fluorapatite is hexagonal, optical and x‐ray observations indicate that has a monoclinic space group. All crystals of this compound are highly twinned. At about 200 °C a transition to a hexagonal p…
G. R. Penzer and G. K. Radda, Q. Rev. Chem. Soc., 1967, 21, 43 DOI: 10.1039/QR9672100043
Abstract To calculate the elastic constants, (C ij ), of the polyethylene (PE), Born's dynamical theory of long wave method has been used for a model of interatomic interactions representing inter‐ and intramolecular force fields. Among various types of interaction potentials between nonbonded atoms, two sets of H‐H,…
Abstract Impact strength and damping as functions of temperature have been compared for eight polymers with typical differences in damping behavior, viz., four methacrylate polymers, a polyphenylene oxide, a polycarbonate, a polyoxymethylene, and a rigid polyethylene. If a damping maximum is caused by a movement withi…
Iron foil specimens were anodically polarized by means of a potentiostat in , , and a sodium borate‐boric acid solution ( p H, 8.5). Both passive, active, and transpassive regions of the polarization curve were studied for each solution. The oxide films were examined while still in contact with the iron foil by select…
Abstract Refined expressions, amendable to experimental testing, for the equilibrium elastic strains in epitaxial overgrowths are derived, based on earlier theories by van der Merwe and Cabrera. Continuous films as well as isolated nuclei on substrates are considered.
A study has been made of all the known factors which limit the performance of high resolution (0.07 to 0.01 eV FWHM) monochromators. These limiting factors have been incorporated into design equations for the optimum (maximum current output) monochromator. The conclusions are tested by performance measurements on a pr…
Abstract A study has been conducted of the kinetics of the reaction of ether alcohols, primary and secondary methoxypropanols, with phenyl isocyanate in the presence of metal catalysts. The proximity of the methoxy and methyl groups to the hydroxyls had a significant effect on the reaction rates as did the type and co…
Abstract Die Bereichsstrukturen, die auf der Basisebene eines Kobalteinkristalls auftreten, wurden experimentell und theoretisch untersucht. Die Vielfalt der Erscheinungen läßt sich deuten, wenn man zu den bisher betrachteten Energietermen noch die magnetostriktive Eigenenergie hinzunimmt. Diese Energie beherrscht vor…
Abstract The properties of molecular weight fractions of linear polyethylene, encompassing the range 3 × 10 3 to 1.5 × 10 6 , which were isothermally crystallised at low undercooling at. atmospheric pressure, were studied. Marked changes in various thermodynamic and mechanical properties are observed with molecular we…
Silicon avalanche diodes have been mounted on diamond to achieve a continuous power density more than twice that achieved on copper. A pair of parallel connected wafers oa a single sample of diamond produced 4.7 watts of CW power at 13.3 GHz using a room temperature heat sink.
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Infrared spectra of pyrazole in the vapour and solid states and in solution are reported and discussed. From these, and by comparison with the spectra of N-deuterio-, 3-methyl-, and 3,5-dimethyl-pyrazole, and other simple five-membered heterocycles, a vibrational assignment is proposed.
Abstract When an amorphous polymer is stretched uniaxially, the chain molecules are oriented along the stretching direction. Orientation causes an anisotropy of the macroscopic physical properties with rotational symmetry about the stretching direction. The phenomenological treatment of the properties exhibited by a u…
An experimental study has been made of the hydrolysis of UN in water vapour+argon mixtures of controlled composition. The kinetics of reaction are followed gravimetrically and by estimation of the ammonia liberated. For powdered UN the reaction proceeds rapidly above ∼340°C. Some specimens hydrolyze completely to UO2,…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTMetal hydrides. Hydrogenation and isomerization catalystsLynn H. SlaughCite this: J. Org. Chem. 1967, 32, 1, 108–113Publication Date (Print):January 1, 1967Publication History Published online1 May 2002Published inissue 1 January 1967https://pubs.acs.org/doi/10.1021/jo01277a…
The effect of aniline and aniline derivatives on the electrochemical characteristics of iron in H 2 SO 4 has been studied using relaxation techniques. Armco iron corrosion was found to be inhibited primarily by an adsorption mechanism. However, evidence was noted which suggested a contribution from a “surface chelate.…
The thermal and X-ray analysis has been made of the decomposition of the trisoxalato-complexes potassium ferric oxalate, sodium ferric oxalate, and ammonium ferric oxalate. The reaction stoicheiometry is described, and the thermal properties of the ammonium complex have been compared with those of ferrous oxalate and…