Materials Literature
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Phosphoglycerate mutase of Bacillus subtilis was purified to apparent homogeneity. It specifically required manganese ions for stability and activity, but it does not need 2,3-diphosphoglycerate as cofactor; the Km for Mn2+ is about 4.5 micrometer. Enzyme activity was inhibited by heavy-metal ions, 2,3-butanedione, an…
The diffuse-cone model, developed on the basis of the existence of orientational disorder in smectic phases, is valid for all smectic A and C phases, and also, with appropriate modifications, for all other smectic phases. The fundamental angular parameter is not the optical tilt angle τ, but the preferred molecular ti…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTElectrochemical oxidation of some mesocyclic dithioethers and related compoundsGeorge S. Wilson, Dale D. Swanson, Jacob T. Klug, Richard S. Glass, Michael D. Ryan, and W. Kenneth MuskerCite this: J. Am. Chem. Soc. 1979, 101, 4, 1040–1042Publication Date (Print):February 1, 1…
Abstract It is shown that under conditions of uniaxial creep the fracture of high density polyethylene can be categorized as one of three types, depending upon the magnitude of the applied load, molecular architecture, and environment. When subjected to relatively large loads, the specimens neck and then fracture almo…
Cathodoluminescence of Sm 3+ , Eu 3+ , and Yb 3+ in is known to be enhanced by a trace of Tb 3+ or Pr 3+ . Nd 3+ , Gd 3+ , Dy 3+ , Ho 3+ , Er 3+ , and Tm 3+ show similar enhancement of efficiencies by addition of Tb 3+ or Pr 3+ . For an electron beam with a current density of about 10 −4 A/cm 2 , in a raster of about…
Abstract Alkylammonium ion exchange on mixed-layer minerals gives detailed information about the variation of cation density in succeeding interlayer spaces. Three mixed layer samples from Japan (supplied by Dr. H. Kodama) were investigated. Their nearly 1:1 interstratification is based on regularly alternating high-…
The nature of the interface between anodically grown oxide films and gallium arsenide substrates was studied using Raman backscattering. Room-temperature spectra of GaAs covered with as-grown anodic films as well as anodized samples dried under nitrogen at 250°C showed only the first-order longitudinal (LO) and transv…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPreparations and properties of nitrosyl complexes of iron tetramethylcyclam. X-ray structures of [Fe(C14H32N4)NO](BF4)2, a S = 3/2-1/2 spin-equilibrium complex, and [Fe(C14H32N4)(NO)(OH)](ClO4)2.CH3CNKeith D. Hodges, R. G. Wollmann, S. L. Kessel, D. N. Hendrickson, D. G. Van…
Abstract The three isomorphic forms of collagen present in muscle have been located by indirect immunofluorescence using collagen type specific antibodies. Type I collagen was located in the epimysium and perimysium, type III primarily in the perimysium as fine lace‐like fibres, and type V virtually confined to the en…
Abstract The steady state demixing of an initially homogeneous oxide solid solution (A, B)O in an oxygen potential field is studied theoretically and experimentally. In case that D A > D B ≫ D 0, the crystal is shifted with respect to the oxide lattice system toward the higher oxygen potential and is enriched in A…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTElectronic spectroscopy of polyatomic molecules by low-energy, variable-angle electron impactAron. Kuppermann, Wayne M. Flicker, and Oren A. MosherCite this: Chem. Rev. 1979, 79, 1, 77–90Publication Date (Print):February 1, 1979Publication History Published online1 May 2002P…
Abstract The texture and the pore size distribution of a set of styrene divinylbenzene copolymers, prepared by suspension polymerization with various compositions and various amounts of ethyl‐2‐hexanoic acid as diluent, have been studied using nitrogen adsorption‐desorption isotherms, mercury porosimetry, and scanning…
The crystal structures of a number of globular proteins are currently available. An analysis of the distribution of side-chains among different allowed conformations in these proteins has been carried out. The observed conformations of individual residues are discussed on the basis of well-known stereochemical criteri…
Collagenous substrates are reported to promote the accumulation of extracellular matrix materials by epithelia in culture. Glycosaminoglycan (GAG) metabolism is compared in secondary cultures of mouse mammary epithelial cells maintained on plastic or type I collagen gel substrates. The incorporation of 35SO42- into GA…
Abstract A model is presented in which the appearance of displacive phase transitions is explained by short‐range internal forces. Electrically charged or uncharged parts of the structure are squeezed out of symmetrical positions and thus lead to a symmetry‐lowering and to phase transitions of ferroelectric or pure st…
Abstract Resonance and pre‐resonance Raman spectra are presented for the 1:1 and 3:1 solid complexes of perylene with tetracyanoquinodimethane (TCNQ). Selective resonance enhancement was observed for perylene. A study of the frequency dependence of the Raman intensities shows that, although these are weak complexes, c…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTFar-infrared spectra of ammonium, potassium, rubidium, and cesium metavanadatesShinji Onodera and Yusaku IkegamiCite this: Inorg. Chem. 1979, 18, 2, 466–468Publication Date (Print):February 1, 1979Publication History Published online1 May 2002Published inissue 1 February 197…
Abstract Data are presented on the second order Raman spectrum of rutile TiO 2 for various scattering geometries, at room and liquid N 2 temperatures. The results of a standard critical point analysis (i) allow the most important addition processes at low energies to be identified, (ii) indicate the importance of matr…
The rotational behavior of the ammonium groups in the high-temperature cubic phase of the perovskite NH4ZnF3 has been investigated, using incoherent quasielastic neutron scattering. The measurements were carried out for various wave vector transfers between 0.68 and 5.52 Å−1 and for temperatures between the transition…
In this paper a survey is given of some ultrastructural properties of synthetic hydroxyapatite. The preparation method by which single crystals with a length in the range of 0.1-3.0mm and a defined purity and stoïchiometry can be produced is given. Two groups of materials are considered in detail: carbonate-rich (grea…