Materials Literature
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Mössbauer spectra of the polycrystalline form of the square planar compound α,β,γ,δ-tetraphenylporphinato–iron (II) have been observed at a variety of temperatures. Analysis of the resulting spectra yield a positive electric field gradient interaction with quadrupole splitting ΔE=1.51 mm/s (4.2 K) and 1.52 mm/s (300 K…
An electronegativity scale is derived for the noble and transition metals, based on their electron-band theory description. The tendency of $d$-band electron and hole states to hybridize is used to estimate the propensity for a particular metal to gain or lose $d$-electron count and this, in turn, is used to provide t…
Ultraviolet optical absorption, emission, and excitation spectra are presented for 14-MeV neutron-irradiated high-purity crystalline ${\mathrm{Al}}_{2}$${\mathrm{O}}_{3}$. Low-temperature polarized excitation spectra for the 3.8-eV luminescence correlated well with polarized absorption at 4.8 eV (both polarizations) a…
Experimental results are reported on S-state ions incorporated into PbFCl-type tetragonal single crystals. The spin Hamiltonian parameters of these ions are determined and correlated with structural and physico-chemical properties of the studied compounds. The experimental b 2 0 spin Hamiltonian parameters vary linear…
Abstract The synthesis of sterically hindered 1,1′, 3,3′‐tetraethylbenzimidazolotriazatrimethine cyanine dyes, their electron absorption spectra and that of their photo‐products (inverse photochromism) is described. Kinetic data of the thermally reversed reaction of the photo‐bleached compounds are given. The differen…
Crystals of a nearly one-dimensional salt, CsMn${\mathrm{Br}}_{3}$, which have been doped with trivalent neodymium, exhibit emissions from both ${\mathrm{Nd}}^{3+}$ and ${\mathrm{Mn}}^{2+}$. At room temperature the emission from ${\mathrm{Nd}}^{3+}$ is strikingly intense, much stronger than the ${\mathrm{Mn}}^{2+}$ em…
Abstract Six different segmented copolyether‐esters based on polybutyleneterephthalate as the hard and oligotetramethylene oxide glycols as the soft segments were studied. The weight fraction of the hard segments varied between 0.26 and 0.72 and the soft segment had an average molecular weight of either 1000 or 2000.…
Abstract A number of diacylperoxides, peroxydicarbonates, peresters and dialkylperoxides with various substituents were chosen to investigate their homolytic decomposition under pressures of up to 3000 bar and high temperatures of up to 200°C, discontinuously in steel autoclaves, in an optical high pressure cell and i…
We report results from x-ray experiments on mixtures of N-($p$-hexyloxybenzylidene)-$p$-aminobenzonitrile (HBAB) in N-$p$-cyanobenzylidene-$p$-$n$-octloxyaniline (CBOOA); very recent microscopic observations on mixtures of cyanohexyloxybiphenyl in cyanooctyloxy-biphenyl are in agreement with these results. The evidenc…
Abstract EPR parameters for atomic hydrogen in three nonequivalent special positions at the twofold axis of the monoclinic structure of brazilianite, formed by X-ray irradiation at room temperature, are reported. The g-factors are practically isotropic and close to the free electron value, but the hyperfine splittings…
Conference Article| December 01 1978 Conformational Stability of Lactate Dehydrogenase from Bacillus thermus-aquaticus SUSAN LAKATOS; SUSAN LAKATOS 1Department of Enzymology, Institute of Biochemistry, Hungarian Academy of Sciences, H-1502 Budapest, P.O.B. 7, Hungary Search for other works by this author on: This Site…
Conference Article| December 01 1978 Citrate Regulation of NADP+-Specific Isocitrate Dehydrogenase of Aspergillus niger MICHAEL MATTEY; MICHAEL MATTEY 1Department of Biochemistry, University of Strathclyde, Glasgow G4 0NR, Scotland, U.K. Search for other works by this author on: This Site PubMed Google Scholar ISABELL…
Detailed luminescence and lifetime data are presented for the mixed crystal system Al2xGa2(1−x)O3:Cr3+, where x=0, 0.02, 0.20, 0.35, 0.98, 1.0. The experimental data, obtained under broadband excitation at 77 K and 4 K, indicate that our pressure-grown microcrystalline samples all have the corundum (α-Al2O3) structure…
Some basic considerations of clay mineralogy suggest that potassium chloride, which is readily available in Israel from the Dead Sea, may significantly improve the engineering properties of heavy clay. This paper describes the results of a laboratory investigation into the effect of potassium chloride on the engineeri…
This paper describes tracking and ignition phenomena of distribution cable and sheet specimens of polyvinyl chloride (PVC) resin on the basis of experimental results obtained by a test method conforming to the IEC tracking test method. Also, the processes of tracking associated with the ignition and combustion of PVC…
Abstract Kaolinite is synthesized in approximately the same time in three temperature ranges: (1) from 200–250° to 350–400° (hydrothermal processes); (2) from 120 to 175° (semihydrothermal ones); (3) at ordinary temperature. It is thus evident that the rate process cannot be explained by the Arrhenius equation only, b…
Abstract In‐plane mechanical properties, coefficients of thermal and hygroscopic expansion, and dimensional changes due to stress relaxation were measured as a function of direction in one, three, and five‐mil polyimide films. Although these films were made by a casting process, they exhibited significant anisotropy i…
Abstract The chemical and electrical stabilities of 7,7,8,8‐tetracyanoquinodimethane (TCNQ) salts composed of neutral TCNQ (TCNQ ˆ ), anion radicals of TCNQ(TCNQ − ·), and polycation polymers were studied by measuring their electronic spectra and resistivities (ρ). The results of spectral and chemical analyses confirm…
Résumé Les analyses thermiques (A.T.P. et A.T.D.) de la palygorskite ont été réalisées entre 20 et 900° La palygorskite contient trois types d'eau nettement différenciés par leur rôle dans la structure. Cependant, les analyses thermiques indiquent un chevauchement des domaines de température où ces diverses molécules…
A model for intergranular crack growth is developed in which atoms are deposited preferentially in a zone ahead of the crack tip. The crack remains sharp provided the length of the diffusive plating zone is much larger than the crack width. The crack velocity depends on a high power of the applied stress. Instabilitie…