Materials Literature
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The structural characteristics of four random network models of B2O3 glass are discussed, and their computed X-ray radial distribution functions are compared with experiment. A random network based on the boroxol ring hypothesis gives marginally the best agreement with the observed distribution function at low interat…
Partial ionic and electronic dc conductivities and compressional creep rate were measured for hot‐pressed poly crystalline AI 2 O 3 made from AI‐isopropoxide (AI 2 O 3 (II)). The undoped material was found to contain 1.5×10 18 cm −3 fixed valency acceptors (Mg). Properties of undoped material and material doped with F…
Abstract Uni‐ and biaxial stretching of poly(ethylene terephthalate) (PET) specimens of appropriate geometry at temperatures near the glass‐rubber transition may lead to non‐uniform deformation unless the draw ratio exceeds a critical value, the natural draw ratio, characteristic of the onset of strain hardening due t…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPhotoatropisomerization of "picket-fence" porphyrins and their metal complexesRuth A. Freitag, Janet A. Mercer-Smith, and David G. WhittenCite this: J. Am. Chem. Soc. 1981, 103, 5, 1226–1228Publication Date (Print):March 1, 1981Publication History Published online1 May 2002P…
Abstract The synergism in limiting oxygen index found in BPA carbonate–dimethylsiloxane block polymers (BPAC/DMS) is correlated with a rise in yield of pyrolytic char and an improvement in char oxidation resistance. These changes in turn are related to a peaking of fractional silicon retention in the char at a resin c…
Abstract— The formation of the cation radical of methyl viologen was established when an aqueous solution containing zinc‐meso‐tetraphenylporphyrintrisulfonic acid, methyl viologen and mercaptoethanol was irradiated by visible light. The reduction of methyl viologen has been studied kinetically and the reduction rate…
Abstract Organic compounds containing oxygen and nitrogen like alcohols and pyridine were readily incorporated into the bulk of heteropoly acids, while hydrocarbons such as butenes and benzene were adsorbed only on the surface. It was found in the dehydration of ethanol over H3PW12O40 that ethylene was yielded predomi…
Abstract The limiting oxygen index (LOI) has been determined for each of a large number of silicone‐containing resins, principally dimethylsiloxane (DMS) block polymers varying widely in DMS content and hard block type. A synergistic enhancement in LOI of varying strength is seen in several families of resins. For the…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTStepwise reduction of carbon monoxide to methane on a triosmium cluster face. Preparation and characterization of undecacarbonyl(methylene)triosmiumGuy R. Steinmetz and Gregory L. GeoffroyCite this: J. Am. Chem. Soc. 1981, 103, 5, 1278–1279Publication Date (Print):March 1, 1…
Two year sea water immersion tests were carried out at four North American sites on a wide range of austenitic stainless steels. Some of these steels were found to be completely free from crevice corrosion at all exposure sites. Immersion of the alloys in FeCl3 in the laboratory provided a more severe test of their cr…
Abstract The luminescence spectra of CaO and SrO activated with Pb 2+ or Bi 3+ ions show vibrational structure. The features in the spectra are discussed by considering the PbO (BiO ) octahedron as an isolated unit in the rocksalt lattice. The luminescence spectra of Tl + ‐activated CaO and SrO do not show vibrational…
The magnetic properties of a series of amorphous Pr1−xFex alloys (.45⩽x⩽ .90) prepared by spin melting are reported. Use of high purity constituents significantly increases the range over which Roentgen amorphous alloys can be obtained by this technique. The ratio of spontaneous to saturation magnetization (at 95 kOe)…
Abstract A new type of polyesterimide has been synthesized by polycondensation of a dicarboxylic acid containing an internal imide group with ethylene glycol. The dicarboxylic acid was synthesized by reacting aminobenzoic acid with trimellitic acid anhydride in N, N ‐dimethylformamide solution. Three isomeric (ortho,…
Abstract Blends prepared by mixing rubbers with plastics in the molten state have been known and used for a number of years. The stiffness of such blends vary widely with both the proportions of rubber to plastic and with material selection, even at equivalent rubber to plastic proportions. This report describes corre…
We present an accurate integral equation for the pair and triplet distribution functions of a simple classical liquid. The only approximation in the theory, the representation of the triplet distribution function, is improved systematically beyond the superposition approximation by a graphical resummation of the densi…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTMagnetic and spectroscopic properties of FeIIFeIII2(CH3CO2)6L3, L = water or pyridine. Direct observation of the thermal barrier to electron transfer in a mixed-valance complexChester T. Dziobkowski, James T. Wrobleski, and David B. BrownCite this: Inorg. Chem. 1981, 20, 3,…
Mechanically hard, electrically insulating (diamondlike) carbon thin films have been produced by low energy carbon ion beam deposition and by decomposition of butane gas. Deposition parameters are presented for these two methods. The ion beam films can be produced with or without a secondary discharge in the ion sourc…
Calculations are presented of the intensity of radiation scattered by a polydisperse system of spherical particles at finite concentrations where interparticle interference of the scattered waves becomes important. The results apply to small-angle (x-ray and neutron) scattering and to light scattering of a solution of…
The slow decay of NH+3 and NH+2 centers in ammonium sulfate produce a new, very stable, paramagnetic center that has been identified as NSO2−4. This center has g values of gx=2.012, gy=2.011, and gz=2.007 with the corresponding hfi constants Ax= Ay=0.0 and Az=25.2 G. No change in this center is observed on passage of…
Complex dielectric function ε (0, ω) and energy-loss function -Im [ ε (0, ω) -1 ] of the 3d transition metals (V, Cr, Fe and Ni) are calculated within RPA with the use of the energy values and the wave functions determined by the APW method in the energy range 0–40 eV and are compared with experiment. The theoretical…