Materials Literature
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Compressive strength of SiC and Al 2 O 3 is determined over a wide range in loading rate. The results are interpreted in terms of the tensile growth of axial microcracks, controlled by two distinct mechanisms. The first is a material‐dependent, thermally activated process operative at strain rates 10 2 s; the other is…
The influence of potential and nominal sea water velocity upon the nature of calcareous deposits formed upon a cathodic steel surface has been investigated. Specific attention was focused upon change with exposure time of the current density to maintain a prescribed cathodic potential and upon thickness of the calcare…
Abstract Measurements on the thermal expansivity α ∥ and α ⟂ (along and normal to the draw direction, respectively) have been carried out for a series of oriented polymers with widely different crystallinities (0.36–0.81) and draw ratios (1–20) and over large temperature ranges covering the major amorphous transitions…
Copolyesters (CPEs) prepared by the transesterification reaction between aromatic and aliphatic polyesters were hydrolyzed by Rhizopus delemar lipase. The susceptibility of CPEs to hydrolysis by this lipase dropped off rapidly during the initial stage of the transesterification reaction and increased gradually as the…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTNew approach to bonding in transition-metal clusters and related compoundsA. J. StoneCite this: Inorg. Chem. 1981, 20, 2, 563–571Publication Date (Print):February 1, 1981Publication History Published online1 May 2002Published inissue 1 February 1981https://pubs.acs.org/doi/1…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCharge-transfer diffusion rates and activity relationships during oxidation and reduction of plasma-polymerized vinylferrocene filmsP. Daum and Royce W. MurrayCite this: J. Phys. Chem. 1981, 85, 4, 389–396Publication Date (Print):February 1, 1981Publication History Published…
Abstract Group theoretic methods are used to list by c repeat and space group polytypes of mica with layer-number N ≤ 24, kaolinite and cronstedtite with N ≤ 12, and chlorite with N ≤ 6. General formulas are given to count the total number of polytypes of these minerals with any layer-number N .
Abstract Group-theoretic methods arising from Pólya's theory of counting are used to enumerate close-packings and polytypes of ZnS, CdI 2 , and SiC having layer-number N ≤ 50. The close-packings are further classified by space group. The barium ferrites of the form M N Y S with N = 2,4,6,8, lO and S ≤ 20 are enumerate…
It had been shown previously that the heat-stable polypeptide of the ATP-dependent proteolytic system of reticulocytes, designated APF-1, forms covalent conjugates with protein substrates in an ATP-requiring process. We now describe an enzyme that carries out the activation by ATP of the polypeptide with pyrophosphate…
A broad review of the physics of point defects, i.e. electrically active and neutral impurities and impurity complexes is given. Basic material science which is crucial for understanding the physics is summarized in an introductory section. It is followed by the detailed description of the novel measurement techniques…
The corrosion rate of copper in laboratory tests is shown to be a sensitive function of relative humidity, sulfur dioxide, hydrogen sulfide, ozone, hydrogen chloride, and chlorine concentrations. Observed indoor corrosion rates obey log normal statistics over the field population of this study. Also, the observed indo…
Abstract The crystal structure of a natural tobermorite from Zeilberg, Maroldsweisach, Germany (average formula Ca 2.2 5 [Si 3 O 7.5 s(OH) 1.5 ].-1H 2 O), is solved using the data obtained from an automatic diffractometer. For the structure determination only the sharp main reflexions are considered. The crystal data…
A fluorescent reagent, N ‐(1‐pyrenyl)iodoacetamide, was conjugated to rabbit skeletal muscle actin at the site of the most reactive sulfhydryl group, and fluorescence characteristics (excitation and emission spectra, quantum yields, lifetimes) of the conjugate were investigated. Associated with polymerization of label…
Luminescence-excitation spectra of the GR defect have been recorded at high resolution for an irradiated natural semiconducting diamond. Luminescence produced in the GR1 region was monitored while the wavelength of the exciting radiation was scanned over the GR1 and GR2-8 absorption systems and part of the ultraviolet…
Pressure-induced high-temperature superconductivity is observed in semiconducting ${({\mathrm{Sn}}_{x}{\mathrm{Eu}}_{1\ensuremath{-}x})}_{y}{\mathrm{Mo}}_{6}{\mathrm{S}}_{8}$, where $0<~x<~0.1$ and $y=1.0 \mathrm{and} 1.2$, having a carrier concentration \ensuremath{\simeq}${10}^{19}$/${\mathrm{cm}}^{3}$ at 4.2…
Starting from an atomistic sterical hindrance potential, translational and orientational motion of the N${\mathrm{O}}_{2}$ group in the deformable lattice are described. The reorientations of the N${\mathrm{O}}_{2}$ group in the paraelectric phase occur essentially by rotations around the crystallographic $\stackrel{\…
Dispersing coarse grains of Al2O3 in a fine-grained matrix of the same material a bending strength of about 500 MPa and fracture toughness of 8 MPa m1/2 are realized on conventionally as-sintered specimens. The improved mechanical properties of the bidisperse structure can be explained by residual stress initiated mic…
Complex admittance measurements are performed on high-purity ceramics prepared by means of the alkoxide synthesis and on less pure ceramics obtained from the citrate synthesis. The results on ceramic materials with grain sizes ranging from 0.4 to 20 μm are compared with those from a single crystal. The activation enth…
As an extension of Table 7.1.5B of International Tables for X-ray Crystallography [(1967), Vol. II. Birmingham: Kynoch Press], the possible stacking variants up to ten layers are arranged according to the percentage of hexagonal stacking. A method is given which allows one to calculate the number of possible stacking…
On the basis of the available force fields for the S8 ring the vibrational Raman intensities of an α-S8 single crystal and of a randomly oriented polycrystalline sample are interpreted in the frame of the bond polarizability model. The whole set of Raman tensors of the S8-molecular ring and of the single crystal inclu…