Materials Literature
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In acetone and at subambient temperature, manganese complexes of 1,4,7-trimethyl-1,4,7-triazacyclononane-catalyse the selective oxidation of many alkenes and styrenes to epoxides with an efficient use of H2O2; the regio- and chemo-selectivity resemble those of manganese-porphyrin catalysts.
No abstract available.
Synthetic and X-ray structural details, optical and vibrational spectroscopic, and thermal properties of the materials [(CH 3 ) 4 N] 2 M 2 Ge 4 S 10 (where M = Cu, Ag), are described for the first time. Rietveld PXRD full-profile structure refinements of [(CH 3 ) 4 N] 2 M 2 Ge 4 S 10 reveal a novel open-framework arch…
The synthesis of carbon nanotubes filled with silver, gold, and gold chloride is described. The resulting materials have been studied by high-resolution electron microscopy, X-ray powder diffraction, and energy-dispersive spectroscopy (EDS). The EDS data were obtained using a high-resolution electron microscope equipp…
A parametric model has been developed to predict the performance of body armor systems under impact by a chunky steel projectile of arbitrary mass, shape, impact velocity, and impact obliquity. The model, which is based on a six-dimensional non linear regression analysis of extensive test data for Kevlar 29, is capabl…
Tissue engineering has recently attracted a great deal of attention for its potential in repairing, reconstructing, regenerating, or replacing tissues in damaged or diseased organs. A number of tissues and organs have already been investigated using this approach, including cartilage, liver, skin, bone, tendon, ureter…
Nanometer-sized silicon particles have been produced by ultrasonic dispersion of thin sections of porous silicon (PS) in organic solvents. The particles have been characterized by HRTEM (high-resolution transmission electron microscopy), FTIR (Fourier transform infrared) spectroscopy, and fluorescence spectroscopy. HR…
The temperature-programmed reduction of three Pd−Cu/KL-zeolite bimetallic catalysts has been studied using X-ray absorption near edge spectroscopy (XANES) and infrared spectroscopy with the probe molecule CO. We show that complete alloying with electronic perturbation of both components (with respect to their metallic…
We studied the molecular dynamics of vanadyl−chelate complexes covalently attached to the surface of cascade polymers, dendrimers. The rotational correlation times of the ion−chelate complex were determined from computer simulations of their EPR spectra. The chelate 2-(4-isothiocyanatobenzyl)-6-methyldiethylenetriamin…
ABSTRACT Edible films using wheat gluten as the structural matrix with or without different lipid components and pure lipid films were tested for sorbic acid retention properties. A diffusion mechanism following Fick's first law was identified. An experimental procedure was developed for determining the diffusivity co…
We study the slippage of a highly viscous polymer melt ( P monomers per chain) on a solid substrate grafted by a few smaller chains in the mushroom regime ( N monomers per chain, grafting density ν). The friction is provided by the sliding motion of the P chains of the “skin” (thickness R p = P 1/2 a ) which are entan…
The use of adjustable-speed drives requires transformers capable of withstanding high levels of harmonic currents under normal operating conditions. Experience has been that overheating problems are much more common with dry-type transformers than with liquid-filled transformers. Transformer insulation life is determi…
We report here a prototype material for the sustained catalytic decontamination of mustard analogues with the ultimate goal being the fabrication of self-decontaminating clothing. H 5 PV 2 Mo 10 O 40 ( 1 ) can be supported on carbon cloths as well as powders, with 1 /Ambersorb 572 being the best material (high catalyt…
We have examined the structural changes in the boron−oxygen network that result from chemical modification of glassy boron oxide by potassium oxide. By means of boron-11 dynamic angle spinning (DAS) NMR and Raman spectroscopies, we have identified changes in the structure resulting from conversion of three-coordinate…
Monovalent cations activate the pyridoxal phosphate-dependent reactions of tryptophan synthase and affect intersubunit communication in the alpha2beta2 complex. We report refined crystal structures of the tryptophan synthase alpha2beta2 complex from Salmonella typhimurium in the presence of K+ at 2.0 angstrom and of C…
We have investigated the structure of five disilicate glass compositions K 2 O·2SiO 2, (Na 0.25 K 0.75 ) 2 O·2SiO 2, (Na 0.50 K 0.50 ) 2 O·2SiO 2, (Na 0.75 K 0.25 ) 2 O·2SiO 2, and Na 2 O·2SiO 2 using 2D 17 O Dynamic Angle Spinning (DAS) Nuclear Magnetic Resonance (NMR). The nonbridging and bridging oxygen sites can b…
The synthesis, electrochemistry, spectroscopy, and structural characterization of two high-valent phenyl sigma-bonded cobalt corroles containing a central cobalt ion in formal +IV and +V oxidation states is presented. The characterized compounds are represented as phenyl sigma-bonded cobalt corroles, (OEC)Co(C(6)H(5))…
ADVERTISEMENT RETURN TO ISSUEPREVCommunication to the...Communication to the EditorNEXTAn Efficient Rhodium(I) Initiator for Stereospecific Living Polymerization of PhenylacetylenesYasuhisa Kishimoto, Tatsuya Miyatake, Takao Ikariya, and Ryoji NoyoriView Author Information ERATO Molecular Catalysis Project, Research D…
We use scaling arguments to determine the patterns that form when Y-shaped AB copolymers are grafted onto a flat surface. One “arm” of the Y is an A homopolymer, and the other arm is an incompatible B chain, and the short “stem” tethers the entire copolymer to the surface. We investigate the behavior of the brush form…
This study focuses on interfacial bonding between intergranular silicon carbide particles and an alumina matrix, to determine the creep inhibition mechanism of alumina/ silicon carbide nanocomposites. It is revealed that the silicon carbide/alumina interface possesses much stronger bonding than the alumina/alumina int…