Materials Literature
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The degradation mechanisms of four polyolefins of differing molecular weight were studied by thermogravimetric analysis in order to identify the material properties which facilitate the extraction of ceramic injection molding vehicles. Three weight‐loss processes were identified and the corresponding activation energi…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCrystal structure and magnetic susceptibility of the dinuclear manganese(IV) complex Mn2O2(pic)4.cntdot.MeCN (picH = picolinic acid)Eduardo Libby, Robert J. Webb, William E. Streib, Kirsten Folting, John C. Huffman, David N. Hendrickson, and George ChristouCite this: Inorg.…
Intermetallic compounds with compositions in the vicinity of Al0·6 (Cu, Zn), (Li, Mg)0·3, namely the so-called R, Z, C and τ phases, have been selected for structural studies because of their presumed relation with the Al-Cu-Li quasicrystal. Neutron diffraction data strongly suggest unicity for short- and medium-range…
The anodic current‐voltage characteristics of P silicon which are obtained in electrolyte in the conditions corresponding to porous layer formation are studied in detail and analyzed according to an elementary model which accounts for the depletion layer at the silicon surface and the Helmholtz layer in the electrolyt…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSelf assembly and dioxygen reactivity of an asymmetric, triply bridged diiron(II) complex with imidazole ligands and an open coordination siteWilliam B. Tolman, Avi Bino, and Stephen J. LippardCite this: J. Am. Chem. Soc. 1989, 111, 22, 8522–8523Publication Date (Print):Octo…
Fluorescein-labeled dextrans (FITC-D) from 3 to 5000 kDa (Stokes' radii from 1 to 40 nm) were used to study influx from the plasma into the peritoneum and efflux from the peritoneal cavity into the plasma in normal and ascites tumor-bearing mice and in mice whose peritoneal vessels had been rendered hyperpermeable by…
The fundamental aspects of the structure, the energies of the formation and of the activation of domain walls are summarized for several one-dimensional model systems. The effect of discreteness of atomic lattices on the activation energy of domain wall is described. The motion of walls will be also mentioned.
The first polyoxomolybdates with an MoIINO instead of an MoIV O group are compounds 2 and 3. They were obtained by reductive nitrosylation of complex 1 with hydroxylamine in methanol. Pentamolybdate 2 is transformed into hexamolybdate 3 upon dissolution, for example in CH2Cl2. The structures of both title compounds ar…
By using the recently developed alternating-gradient magnetometer, that combines very high sensitivity and measurement rapidity, we have made observations of magnetic aftereffect in ferromagnetic films of a few atomic layers. These Co films have a perpendicular easy axis due to a large interface anisotropy and square…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTMechanism of reactions of hydrogen peroxide and hydroperoxides with iron(III) porphyrins. Effects of hydroperoxide structure on kineticsTeddy G. Traylor and Joseph P. CicconeCite this: J. Am. Chem. Soc. 1989, 111, 22, 8413–8420Publication Date (Print):October 1, 1989Publicat…
Grinding induces resiual stresses and cracks at and near the surfaces of ceramic workpieces. The residual stresses in several ground ceramics are measured using the curvature method. Four‐point bend tests are conducted to measure the fracture strength of the ground specimens. A fracture mechanics analysis includes the…
The binding of analogues of the 7-methylguanosine-containing cap, m7GTP and m7GpppG, to eIF-4E from human erythrocytes as a function of pH, temperature, and ionic strength is described. From the pH-dependent binding of m7GTP and m7GpppG to eIF-4E, a new model describing the nature of the cap.eIF-4E interaction is prop…
The improvement of mechanical properties of Al 2 O 3 /SiC whisker composites has been studied with emphasis on the effects of the whisker content and of the hot‐pressing temperature. Mechanical properties such as fracture toughness and fracture strength increased with increasing whisker content up to 40 wt%. In the ca…
A method is described for determining an effective, depth dose consistent bremsstrahlung spectra for high-energy photon beams using depth dose curves measured in water. A simple, analytical model with three parameters together with the nominal accelerating potential is used to characterise the bremsstrahlung spectra.…
Films of various iron oxides including FeO, Fe3 O4 , and α-Fe2 O3 were formed on the α-Al2 O3 (0001) surface by a reactive vapor deposition method and characterized by x-ray diffraction and conversion electron Mössbauer spectroscopy (CEMS). The formation range for each phase was determined as a function of the substra…
The three-dimensional structure of a mutant of the aspartate aminotransferase from Escherichia coli, in which the active-site lysine has been substituted by alanine (K258A), has been determined at 2.8-A resolution by X-ray diffraction. The mutant enzyme contains pyridoxamine phosphate as cofactor. The structure is com…
Abstract Bismaleimide polymers offer a thermostability that fills in the gap between epoxies and high temperature polyimides. Bismaleimides of the new generation overcome traditional problems of brittleness and difficult processing. The property transpositions from these tougher, hot‐melt processable resins to the cor…
Abstract The venting and control strategies of a Magnesium Grignard formation reaction were assessed by theoretical predictions of the exotherm and the reaction rate, by simple laboratory measurements of the self heat rate, and by Leung's simplified equations and SAFIRE evaluations, based on DIERS methods. SAFIRE comp…
Abstract A viscous traction interfacial viscometer was constructed to study a mineral oil‐water‐emulsifier system. The effect on interfacial viscosity of the synthetic emulsifiers Span 80 and Pluronic L42 were investigated, along with the bioemulsifier produced by the yeast Torulopsis petrophilum. In the case of the s…
We report a high-resolution x-ray scattering study of the nematic--smectic-A transition around the tricritical point in mixtures of heptyloxypentylphenylthiobenzoate and octyloxycyanobiphenyl. Unusually large susceptibility and correlation length critical exponents are observed; this is explained as a clear example of…