Materials Literature
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The reflectance of evaporated rhenium (Re) and tungsten (W) was measured in the wavelength region from 300 to 2000 Å. Re and W of 99.99% purity were evaporated with a 6-kW fine-focused electron gun and deposited on glass and fused-quartz plates of various temperatures ranging from 40 to 500°C. With Re, films of highes…
Studies have been made of the tempering at 400° and 600°C of h.c.p. and orthorhombic martensitic phases in alloys with up to 32 w/o tantalum, and of the retained β phase in higher tantalum alloys. Precipitation of the equilibrium β phase as disc-shaped particles with the Burgers orientation relation and with a habit p…
Abstract In non-aqueous systems, kaolinite can show, in addition to the physical interactions, considerable chemical activity. This study considers the chemical reactions that can occur at the kaolinite surface and explains these reactions in terms of acid-base interactions. In certain applications the chemical activi…
ESR spectra of the ScS and YS molecules in their ground 2Σ+ states were measured while trapped in solid argon or neon matrices at 4°K. g tensors and hyperfine structure constants for interaction with the metal nuclei were accurately derived, within the ambiguity of multiple matrix sites. Earlier ESR data on ScO were a…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTReaction of catechol with colloidal silica and silicic acid in aqueous ammoniaDennis W. BarnumCite this: Inorg. Chem. 1972, 11, 6, 1424–1429Publication Date (Print):June 1, 1972Publication History Published online1 May 2002Published inissue 1 June 1972https://pubs.acs.org/do…
A common objective in designing a postmortem type of plate-impact experiment is to be able to attribute the observable residual effects (such as residual strain, hardness, or dislocation density) primarily to the conditions which existed while the material was in a state of uniaxial strain. In the past it has generall…
In both pIants and animals the mechanism of ribosomal RNA synthesis is thought to be the same, yet genetic and biochemical evidence points to a dispersed origin along chromosomal DNA in plants
Structural, magnetic, and magneto-optic properties of Mn1−xTixBi films (0≤x≤0.2) prepared by a vacuum-evaporation technique are reported. The crystallographic structure and the order of phase transformations of unsubstituted MnBi films were not altered by Ti. Both low-temperature (LT) phase and quenched high-temperatu…
The effect of impurities on the critical interaction strength for the Mott transition has been investigated using an extension of the Gutzwiller approach to correlation in the metallic state. It is shown that the band narrowing due to impurities causes a reduction of the effective interaction necessary for the transit…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTStructure of tetra-n-propylporphine. Average structure for the free base macrocycle from three independent determinationsPenelope W. Codding and A. TulinskyCite this: J. Am. Chem. Soc. 1972, 94, 12, 4151–4157Publication Date (Print):June 1, 1972Publication History Published…
The normal spinel Fe[Cr 2 ]S 4 has been studied using the Mössbauer effect. Spectra have been collected over the temperature range 2–500 °K. Results are presented for the quantity [Formula: see text], the hyperfine field, and the isomer shift. We find that the magnetically split spectra can be fitted using a zero valu…
Abstract The synthesis and general physical characteristics of the perfluoroalkylene‐linked aromatic polyimides have been discussed in Part I. In this paper the hydrolytic, oxidative, and thermal stabilities of these polymers are compared with those of certain wholly aromatic polyimides. Comparative studies are also m…
Abstract Phosphatization of limestones on the Agulhas Bank, southern tip of Africa
Abstract As to the modes of inhibiting electrode processes, it belongs to the present tasks of the Working Party “Inhibitors” of the European Federation Corrosion first to elaborate valid formulations in definition, nomenclature and classification and second to present a review on methodology for investigating inhibit…
Abstract This paper describes the preparation of a series of novel perfluoroalkylene‐ and ether‐linked aromatic polyimides. Depending on the nature of the precursor diamine, the polyimides were prepared by either melt or solution techniques, the latter via the corresponding poly(amic acids). The polymers were characte…
The paramagnetic resonance spectrum of the iron oxygen-vacancy (${\mathrm{Fe}}^{3+}\ensuremath{-}{V}_{o}$) pair in the tetragonal $\frac{I4}{\mathrm{mcm}}$ phase of SrTi${\mathrm{O}}_{3}$ at 78 \ifmmode^\circ\else\textdegree\fi{}K is analyzed in detail. The spectra observed at $K$ band are fully accounted for using th…
Grain boundary sliding is necessary during diffusion creep to maintain continuity across the grain boundaries. In this paper it is shown, by use of a two-dimensional hexagonal array, that grain boundary sliding will contribute additional axial strain to the specimen as predicted by R. N. Stevens (1971). It is shown, h…
The X-ray patterns of two new smectic modifications (smectic D and Smectic E) are investigated. The D-modification is potically isotropic. A cubic structure is presumed. In the E-modification the pattern exhibits three sharp outer rings besides the inner irng, which points to a higher order compared withthe A, B and C…
Abstract Use of microprobe in analyzing mineralogical-textural relationships in fine-grained materials not readily studied by optical methods
Domain spacing in SmCo5 is observed to increase by a factor of 1.5 at 78 K as compared with the spacing at room temperature. This indicates a difference in domain wall energy, which may explain the experimentally found difference in coercive force.