Materials Literature
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Morphological, x-ray crystallographic and x-ray topographic studies on many specimens grown in this laboratory lead to a consistent description of polytypism in vapour-phase grown ZnS. Crystal growth begins with the emerging of hexagonal 2H needles from the polycrystalline substrate. The needles thicken during the gro…
Bis-(4′-n-alkoxybenzal)-2-chloro-1, 4-phenylenediamines and bis- (4′-n-alkoxybenzal)-2-methyl-1, 4-phenylenediamines with different alkoxy groups have been synthesized. Similar compounds with fluoro, bromo and chloro groups replacing the alkoxy groups have also been prepared. All the compounds show a nematic liquid ph…
The crystal dynamics of sodium nitrite has been studied by coherent neutron inelastic scattering techniques. The normal modes of vibration propagating along the three principal symmetry axes in the crystal at 296°K have been measured. The results have been used to find the parameters of rigid ion models for NaNO 2 in…
The velocity of edge dislocations in 99.999% pure copper crystals has been measured as a function of stress at temperatures from 66°K to 373°K by means of a torsion technique. The range of resolved shear stress was 0 to 15 megadynes/cm2 for seven temperatures (66°K, 74°K, 83°K, 123°K, 173°K, 296°K, 373°K). Dislocation…
The Crystallization kinetics of molten polyethylene subjected to a constant shear stress were investigated theoretically and experimentally. The rate of crystallization depends on the difference of entropy (Δs) between the crystalline and molten state. The constant shear stress in the melt decreases Δs causing an abru…
Almost every kind of material and fabrication process now has to be used to meet the demands of ocean engineering, ranging as it does from hydrofoils to research submersibles, and from giant tankers to offshore drilling rigs. Some of the difficulties are obvious, for example when aircraft-like design procedures must b…
Abstract In the preparation of magnesium oxychloride cement from MgO and MgCl 2 .6H 2 O solution, MgO is sometimes replaced by partially calcined dolomite, MgO.CaCO 3 . In this paper, the suitability of dolomites for this purpose was studied by use of petrographic, d.t.a. and X ‐ray diffraction techniques. It is shown…
A technique has been developed for extracting one of the phases present in Ni-Co-Al-Ti-Cu-Fe permanent magnet alloys heat-treated to give optimum magnetic properties. Examination of such extracts by electron microscopy and electron-probe microanalysis has confirmed previously held theories that the precipitate is stro…
SUMMARY A new centric diatom, Microsiphona potamos gen. et sp. nov. (family Coscinodiscaceae), is described from the Little Miami River, Cincinnati, Ohio, where it occurred at cell densities ranging from 29 to 20,140/ml in surface grab samples during the period May 18–December 14, 1966, contributing an average of 11%…
The major features of the images of dislocation dipoles obtained by two-beam electron microscopy which enable dipoles to be identified and distinguished from other defects are discussed. The positions of stable equilibrium of dipoles in various f.c.c. and b.c.c. materials have been derived using linear anisotropic ela…
Transmission electron micrographs of replicas and glass chips mounted on carbon films can be obtained in the scanning electron microscope. The standard collection system is used and only slight modifications made to the specimen stage.
Photomicrographs are presented of a naval brass which has undergone dezincification, presumably by fresh water. Detailed analysis of them leads to the conclusion that dezincification must have occurred by the mechanism of redeposition of the copper.
The temperature dependences of the saturation magnetization sigma s and of the anisotropy K 1 were measured in single crystals of Mg x Mn y Fe 3-x-y O 4 , 0<or=x<or=0.63, y approximately=0.6. The magnitude and temperature dependence of the anisotropy contributions H 1 of Fe 2+ , Mn 3+ and Fe 3+ ions in B sites were fo…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTEffect of ring size on the stability of polyamine complexes containing linked consecutive ringsDavid C. Weatherburn, Edward J. Billo, J. Paul Jones, and Dale W. MargerumCite this: Inorg. Chem. 1970, 9, 6, 1557–1559Publication Date (Print):June 1, 1970Publication History Publ…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPreparation, properties, and structure of cuprous ammonium thiomolybdateW. P. Binnie, Michael J. Redman, and W. J. MallioCite this: Inorg. Chem. 1970, 9, 6, 1449–1452Publication Date (Print):June 1, 1970Publication History Published online1 May 2002Published inissue 1 June 1…
The varieties of compounds and solid solutions in which simultaneous ferroelectric properties and magnetic order have been demonstrated are reviewed and literature references are given. Materials investigated so far have contributed to fundamental understandings of processes in crystals and a variety of techniques and…
The variation of total loss under the tensile stress applied along the near [001] direction has been measured on the single crystals with (110) [001] orientation of 3% silicon-iron. It has been found that the total loss was greatly decreased with an application of stress. This effect is more remarkable when the orient…
1. A method is described for studying the peristaltic reflex in the guinea-pig or cat isolated colon, using a graded localized intraluminal stimulus consisting of a solid bolus.2. The method gives an easy evaluation of propulsive activity and makes it possible to record simultaneously the segmental activity of the cir…
The prospect that permanent magnets with previously unattainable coercivities and energy products might be made from cobalt-rare earth alloys has caused intense research efforts in the last three years. Alternative ways of preparing magnets from powders and by casting were demonstrated in several laboratories.(BH)_{\m…
Energy levels, linewidths, and oscillator strengths for trivalent neodymium ions in a commercial laser glass were determined from the fluorescence and absorption spectra. The spectra were composed of broad groups of overlapping lines and were deciphered from spectral variations produced by changes in glass temperature…