Materials Literature
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Proton-induced absorption over the 280-700-nm region and growth of that coloring with increasing dosage of proton radiation were determined for three Schott glasses used as focusing elements in the International Ultraviolet Explorer. It was found that the absorption spectra for each glass can be fitted with three Gaus…
Rossmann and Argos [J. Mol. Biol. 109, 99–129 (1977)] observed that each of the two lobes which border the sugar binding cleft of yeast hexokinase contains a similar structural unit of five β-sheet strands and three α-helices. The strands are in the same order and two helices in each unit are on the outside of the mol…
(VSiW1 1O4 0)n− complexes exhibit two kinds of redox systems, those of vanadium (VV-VIV and VIV[sbnd]VIII) and those of the ligand. Electron transfers between the vanadium and the ligand are observed by change in the pH. Electronic spectra are discussed with regard to two types of electronic transitions, intervalence…
Threshold switching has been observed and studied in thin films of NbOx (x?2) in the sandwich configuration and in a single-crystal device having both a gap and sandwich configuration. The recovery curve has been determined by measuring the reswitching voltage after a specific zero-voltage interruption time. Data indi…
ADVERTISEMENT RETURN TO ISSUEPREVArticleProtoporphyrin IX: some recent researchKevin M. SmithCite this: Acc. Chem. Res. 1979, 12, 10, 374–381Publication Date (Print):October 1, 1979Publication History Published online1 May 2002Published inissue 1 October 1979https://pubs.acs.org/doi/10.1021/ar50142a004https://doi.org/…
A mechanical model of the 2/2-twill weave is presented in order to investigate the tensile properties of this weave under biaxial extension. The theory predicts that the compressional deformations of the warp and the weft at their cross-over point produce a superior effect on the tensile properties of the weave, espec…
A critical review is presented of all published data on phase transformation in zirconium and its alloys. Topics discussed include: The α → β transformation; factors affecting the stability of α and β zirconium; transformations in the β-phase including ω-phase formation, eutectoidal decomposition and strain induced tr…
Kirkendall void formation, which has hitherto prevented the use of the external diffusion technique for the manufacture of practical multifilamentary superconducting composites, can be suppressed by using solution anneals to eliminate sites for heterogeneous void nucleation.
The compositional dependence of the Urbach tail of Ge x Se 1- x compounds was measured in the range 0≤ x ≤0.4. The slope of the Urbach tail of Ge x Se 1- x compounds varies greatly with Ge content. It has a maximum at about x =0.3 and a minimum at the stoichiometric composition GeSe 2 . This specific dependence of the…
In Salmonella typhimurium and Escherichia coli, elongation factor Tu (EF-Tu) is methylated as shown by its incorporation of labeled methyl residues from [methyl-3H]methionine. Analysis of the nature of the methyl-containing residues by protein hydrolysis, followed by paper chromatography and high voltage electrophores…
The relationships h1 = h0 + Δhn and n = Δh−1(h1 − h0) [Gabe (1969). In Crystallographic Computing, edited by F. R. Ahmed. Copenhagen: Munksgaard], establishing the correspondence between the crystal indices h1 and the segment indices n of a given reflection, can be used to generate the reflections in the unique set, d…
The overall characteristics of the composites cured with a number of newly synthesized, tertiary aromatic amines compare favorably to those of resins polymerized with commonly used accelerators. Maximum compressive and tensile strength for the composites are obtained only over a narrow concentration range of accelerat…
The developing velocities of the positive and negative corona streamers on insulating plates have been measured by using the dust figure technique at low pressure in air. By applying nanosecond time pulses from 10- to 50-nsec duration to a needle point where the insulating plate is sandwiched in between the needle and…
Abstract Mössbauer spectra of 9 glauconite samples from Upper Cretaceous and Lower Tertiary strata in the South Island of New Zealand contain a broad shoulder due to low intensity absorption continuous between 1.0 and 2.5 mm/sec when the absorber is at room temperature; the shoulder is absent, and sharp peaks are appa…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTElectronic ground-state properties of tetranuclear hexa-.mu.-hydroxo-bis(tetraamminechromium(III))bis(diamminechromium(III)) chloride. A spectroscopic and magnetochemical studyHans U. Guedel, Urs Hauser, and Albert FurrerCite this: Inorg. Chem. 1979, 18, 10, 2730–2737Publica…
Abstract The charge density distribution among different classes of a series of reduced charge mont-morillonites is heterogeneous as in the parent Camp Berteau clay. In addition, charge reduction proceeds inhomogeneously. Up to 20% differences in charge density can be accounted for by aikyl chains extending at the edg…
High-resolution transmission electron microscopy using axial beam illumination was carried out on vacuum-deposited WO 3 , TiO 2 , and MoO 3 films. In as-deposited WO 3 films thinner than 100 Å and films heated at 350°C for 2∼5 h which gave rise to amorphous haloes in electron diffraction, crossed fringe-like structure…
Abstract The dielectric spectra of BaTiO 3 single‐domain and polydomain tetragonal crystals with 180° domain structure are investigated over the wide range of frequencies 10 3 to 10 10 Hz. It is shown that the dielectric permittivity ε 33 of the single‐domain crystals has three regions of dispersion including two regi…
Pedogenic palygorskite is formed in oases soils in the eastern province of Alhasa. The pedogenesis of palygorskite is indicated by the fact that this clay mineral could not be detected in an ancient red bed (Miocene or Pliocene) believed to be the soil parent material. This pedogenic palygorskite is forming at the exp…
The corrosion of metals in the aqueous environments of body fluids involves the setting up of electrochemical corrosion cells. The corrosion produced by these cells is controlled by thermodynamic and kinetic factors. The thermodynamic factors determine the corrosion tendencies; the kinetic factors determine the rate.…