Materials Literature
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The oxidation of vinyl and silyl enol ethers with aqueous hydrogen peroxide was first achieved by the use of peroxotungstophosphate (PCWP) as the catalyst. For example, the oxidation of 1-ethoxy-1-octene with a stoichiometric amount of 35% H(2)O(2) in the presence of PCWP (0.5 mol %) in a mixed solvent of methanol and…
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTLow-Temperature Synthesis of Aluminum Sulfide as the Solvate Al4S6(NMe3)4 in Hydrocarbon SolutionRudolf J. Wehmschulte and Philip P. PowerView Author Information Department of Chemistry University of California Davis, California 95616 Cite this: J. Am. Chem. Soc. 1997,…
A bisphthalocyanine lutetium derivative substituted with benzo-15-crown-5 subunits, [(15C5) 4 Pc] 2 Lu ( 1 ), has been shown to form sandwich complexes with cations such as potassium ion, the complexes further form pillarlike aggregates. Light scattering studies have been carried out as a function of the ratio [K + ]/…
New aliphatic polycarbonates derived from trimethylene carbonate ( 1 ) (TMC, 1,3-dioxan-2-one),have been prepared by ring opening polymerization. The synthesis is achieved by using new aluminum alkoxide initiators which allow for the incorporation of controlled functionality in the resulting polymer. The synthesis of…
Multidimensional transition-state theory was used to simulate methane jump motions in glassy atactic polypropylene at 233 K in the limit of small methane concentrations. Transition states were found with respect to both penetrant and polymer degrees of freedom, using all generalized coordinates associated with atoms i…
As a model for the splitting of pyrimidine base pair defects by DNA photolyase, the uracil dimer and its anion radical have been studied by ab initio HF and MP2 methods. A transition state and an intermediate of the uracil dimer anion radical cleavage reaction have been located. The activation barrier for breaking the…
A study was undertaken of hydrogen accumulation on grain boundaries, at inclusions, and near a kneaded notch tip; the susceptibility for blistering; and hydrogen-induced cracking (HIC) of tubular steels (API C90). Results showed the accumulation coefficients of hydrogen on the grain boundaries, various inclusions, and…
<div class="htmlview paragraph">For meeting 21st-century exhaust emission standards for HD diesel engines, new methods are necessary for reducing NOx and PM emissions without increasing fuel consumption. The stratified diesel fuel-water-diesel fuel (DWD) injection in combination with exhaust gas recirculation (E…
Diamond metal-insulator-semiconductor diodes and field-effect transistors (MISFETs) have been prepared using CaF2 gate insulator and nondoped (in some cases, boron was doped) diamond homoepitaxial films. The resultant capacitance-voltage (C-V) curves and drain current-drain voltage (ID−VD) curves strongly depended on…
In the past few years neutron-scattering experiments have shown very intriguing stripe correlations of spins and holes in hole-doped ${\mathrm{La}}_{2}{\mathrm{NiO}}_{4}$ and ${\mathrm{La}}_{2}{\mathrm{CuO}}_{4}$. As yet, no x-ray-diffraction experiment has confirmed the neutron results and the topic is still controve…
The R –curve for Si 3 N 4 −40 wt% TiN composites was estimated by the indentation‐strength method and compared to that of monolithic Si3N4 with duplex microstructure. Both materials exhibited rising R ‐curve behavior. The Si3N4‐TiN composites, however, displayed better damage tolerance and higher resistance to crack g…
Liposomes have been proposed as potential vehicles for drug therapy targeted to solid tumors, in particular, because of the increased permeability of these tumors to macromolecules. The recent development of Stealth
The low-temperature nesting instability in the quasi-two-dimensional organic conductor, ${\mathrm{\ensuremath{\alpha}}\ensuremath{-}(\mathrm{B}\mathrm{E}\mathrm{D}\mathrm{T}\ensuremath{-}\mathrm{T}\mathrm{T}\mathrm{F})}_{2}{\mathrm{RbHg}(\mathrm{SCN})}_{4},$ has been investigated by ${}^{13}\mathrm{C}$ NMR. Below 12 K…
Abstract A hexagonal mesostructured aluminophosphate was successfully synthesized from the mixture of Al(OiPr)3, 85% H3PO4, tetramethylammonium hydroxide, hexadecyltrimethylammonium chloride, and water.
ADVERTISEMENT RETURN TO ISSUEPREVCommunication to the...Communication to the EditorNEXTPhotomechanical Response in Monolayered Polymer Films on Mica at High HumidityTakahiro Seki, Keisuke Tanaka, and Kunihiro IchimuraView Author Information Research Laboratory of Resources Utilization, Tokyo Institute of Technology, 4…
A number of substituted manganese phthalocyanines ( PcMn ), which are easily soluble in organic solvents, have been synthesized with good yields (up to 76%) and high purity. PcMn with manganese +2 oxidation state without axial ligands was obtained for the first time and thoroughly characterized. It was shown that PcMn…
Previous work has used small-area and imaging XPS to show that differential charging in bulk insulators develops as a result of non-uniform x-ray flux across the surface, causing lateral differential charging. Charging in heterogeneous samples can be further affected by the local sample environment and sample mounting…
Spo0F is a secondary messenger in the "two-component" system controlling the sporulation of Bacillus subtilis. Spo0F, like the chemotaxis protein CheY, is a single-domain protein homologous to the N-terminal activator domain of the response regulators. We recently reported the crystal structure of a phosphatase-resist…
A method is presented to estimate the excess chemical potential of solutes in dense polymer microstructures with a combination of the thermodynamic-integration approach and Widom's particle insertion from MD runs under constant NVT conditions on an atomistic level. The results obtained for pure water systems show good…
Numerical simulations are conducted to examine the effect of randomness in the bubble packing on the local elastic properties of a foam. We find that the response to a small-amplitude strain is spatially inhomogeneous: there are regions (of several bubbles) where bubbles shift their positions in order to prevent disto…