Materials Literature
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Cultures of Myxococcus xanthus develop multicellular fruiting bodies when starved for carbon and nitrogen sources on an agar surface. Under these conditions of severe starvation, cultures rapidly accumulated a compound identified as guanosine tetraphosphate by chromatographic migration of the compound and of its major…
Extremely efficient decarbonylation of aromatic and aliphatic aldehydes has been accomplished catalytically under ambient conditions using solutions of bis(triphenylphosphine)(tetraphenylporphyrinato)-ruthenium(II).
Configurations without strain (as opposed to curvature) in a mesomorphic phase made of long thin rods (like hexagonal liquid crystals) are characterized by local frames of reference undistorted with respect to the ground state and by absence of splay deformation (div t = 0). These constraints lead to an important clas…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTQuantitative determination of surface composition of sulfur bearing anion mixtures by Auger electron spectroscopyN. H. Turner, J. S. Murday, and D. E. RamakerCite this: Anal. Chem. 1980, 52, 1, 84–92Publication Date (Print):January 1, 1980Publication History Published online…
Introduction. The purpose of this paper is to survey recent results related to the second part of Hubert's eighteenth problem (see Hilbert [1900]). This problem, which is concerned with tilings of Euclidean space by congruent polyhedra, will be stated below after the necessary terminology has been introduced. Although…
Abstict -The interacticn between synthetic polyners and the physical environnnnt , especially in tenis of the effects of oxygen and radiant ener , has been extensily studied and reported and thictly useful results haw been obtained by the use of experianntal techniquss of a kind vexy familiar to physical chemists. The…
Proper selection of polymer seal materials must consider restraints imposed by the application and the properties of available materials. Data and concepts presented enable the working vacuum technician to make an educated selection considering chemical and mechanical properties, outgassing, permeation, and nuclear ra…
The 60 Hz flashover performance of 230 kV and 500 kV long-rod polymer insulators is compared to standard ceramic suspension insulator strings under moderate ice conditions. The tests on clean and heavily pre-contaminated insulators were performed indoors to minimize the effects of wind and temperature variations. In g…
Perovskite type layer-structure compounds of the formulas (Cn H2n+1 NH3)2·MCl4 and NH3 (CH2)n NH3MCl4 (M = Cd, Mn, Cu, Fe, n = 1–18) exhibit a variety of structural phase transitions which are connected with the dynamics of the alkyl-ammonium or alkylenediammonium chains respectively. Two classes of phase transitions…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSynthesis and Characterization of Poly(glutaraldehyde). A Potential Reagent for Protein Immobilization and Cell SeparationShlomo Margel and Alan RembaumCite this: Macromolecules 1980, 13, 1, 19–24Publication Date (Print):January 1, 1980Publication History Published online1 M…
The α form of quinol crystallises in the rhombohedral space group R with 54 molecules in each unit cell of hexagonal dimensions a=b= 38.46(2), c= 5.650(3)Å, i.e. three times larger than the cell originally described by Caspari. There are therefore 3 molecules in each asymmetric unit. Two of these are involved in formi…
The influence of Mo on reversible temper embrittlement(RTE)of a low-alloy 2¼Cr-lNi steel with variableP and Mo contents was studied by establishing the relationships among the Charpy impact transition temperature shifts, the nominal P and Mo concentrations, and their intergranular concentrations as measured by Auger e…
The X-ray photoelectron spectra of a range of gold complexes with halide, phosphine, and thiol ligands is reported. Gold(I) and gold(III) complexes can readily be distinguished for each type of ligand. The use of this result is illustrated by following the decomposition of [NEt4][AuBr4] on exposure to the X-ray beam.…
Single crystals of poly(tetramethylene adipate) (PTMA,-[O-(CH2)4-O-CO-(CH2)4-CO]n-) have been prepared by precipitation from solution and by epitaxial deposition on suitable substrates. The crystals grown from solution exhibited two distinct morphologies: most of the crystals were diamond-or truncated diamond-shaped,…
Dose survival curves of lactate dehydrogenase irradiated under aerobic and anaerobic conditions show a sensitizing effect of oxygen for the inactivation of the enzyme. The oxygen effect in the radiolysis of lactate dehydrogenase was analysed by gel filtration and polyacrylamide gel electrophoresis. Under anaerobic con…
An infinite summation method is used to obtain the intrinsic photoemission spectrum of a conduction electron in the sudden limit. It is predicted that an electron at the bottom of the conduction band should have an asymmetry index comparable to that of a core electron and that the strengths of its plasmon satellites s…
The crystal structure of the title compound has been determined from three-dimensional X-ray diffractometer data. Crystals are triclinic, space group P, with Z= 2 in a unit cell of dimensions a= 12.027(6), b= 12.571(8), c= 8.690(5)Å, α= 96.04(5), β= 94.80(5), and γ= 68.20(5)°. The structure was solved by direct and Fo…
Abstract Aus einer Knudsenzelle verdampftes SiO reagiert mit O‐Atomen (Mikrowellenanregung) in einer Argonmatrix zu molekularem SiO 2 . Banden um 1400 cm −1 im IR‐Argon‐Matrixspektrum werden der asymmetrischen Valenzschwingung (ν 3 ) der Isotopenmoleküle Si 16 O 2 , Si 16 O 18 O und Si 18 O 2 zugeordnet. In einer Argo…
An X-ray diffraction method for determination of the degree of crystallinity of indomethacin was established, and the transition rate of indomethacin from amorphous to crystalline form was investigated. The transition of the amorphous form to crystalline form at 20°, 30°and 40°followed first-order kinetics and the Arr…
It has previously been shown that the ordinary liquid–glass transition is just one example of a class of “glass transitions” due to loss of equilibrium which may occur widely in metastable phases of condensed matter. In the present paper, glass-transition phenomena occurring in stable crystalline phases of SnCl2.2H2O,…