Materials Literature
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The temperature dependence of dielectric properties and electrical conduction of $({\mathrm{Sr}}_{1\ensuremath{-}1.5x}{\mathrm{Bi}}_{x}){\mathrm{TiO}}_{3} (0.0133<~x<~0.133)$ was measured from 10 to 800 K. Three sets of oxygen vacancies related dielectric peaks (peaks A, B, and $C)$ were observed. These peaks co…
Combining electron diffraction, x-ray diffraction, and high-resolution electron microscopy techniques, a structural model for the cobaltite $``{\mathrm{Ca}}_{3}{\mathrm{Co}}_{4}{\mathrm{O}}_{9}''$ has been found. This compound is a misfit-layered oxide consisting in two monoclinic subsystems with identical a, c, and \…
Our continuing study of the mechanism of flammability reduction of polymer−layered-silicate nanocomposites has yielded results for polypropylene- graft -maleic anhydride and polystyrene−layered-silicate nanocomposites using montmorillonite and fluorohectorite. Cone calorimetry was used to measure the heat release rate…
Data on a new class of inorganic incommensurate intergrowth suprastructures, viz., layered misfit compounds, are surveyed and systematised. Physical properties of misfit suprastructures are discussed. Possible mechanisms of the effects of the electronic structure and incommensurability on the structural elements of su…
En este trabajo se realiza una revisión acerca del estado actual de los materiales compuestos de matriz metálica habitualmente utilizados en la industria aeronáutica y automotriz. Normalmente, son materiales de base aleaciones ligeras (Al, Ti o Mg) reforzados con fibras o partículas. En esta revisión se repasan las di…
The dielectric behavior of the supercooled aqueous solutions of propylene gylcol, glycerol, poly(vinylpyrrolidone) (PVP), and poly(ethylene glycol)s of different molecular weights has been examined at different concentrations in the frequency range of 10 6 − 10 -3 Hz. Differential scanning calorimetric measurements ha…
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTToroidal Droplet Formation in Polymer-Dispersed Liquid Crystal FilmsGerald H. Springer and Daniel A. HigginsView Author Information Department of Chemistry, Kansas State University Manhattan, Kansas 66506 Cite this: J. Am. Chem. Soc. 2000, 122, 28, 6801–6802Publication…
A new methodology to study the second-order nonlinear optical coefficients of organic materials was developed. The combination of oriented crystal growth (epitaxy or grapho-epitaxy) with grazing incidence X-ray diffraction and second harmonic ellipsometry gives an overview of the relations between the molecular hyperp…
The reactions of Q[Au(acac) 2 ] (Q = N(PPh 3 ) 2 (PPN; a ), NPr 4 ( b ); acac = acetylacetonato) with terminal alkynes of the type HC⋮CC 6 H 4 R-4 in a 1:2 molar ratio affords the complexes Q[Au(C⋮CC 6 H 4 R-4) 2 ] (R = NO 2 ( 1 ), C 6 H 4 NO 2 -4 ( 2 ), ( E )-CH CHC 6 H 4 NO 2 -4 ( 3 )). The same alkynes react with […
This volume compiles information from physics, metallurgy, and mechanical and electrical engineering to epitomize the fundamental characteristics of flat rolling steel. Flat Rolling Fundamentals is drawn from in-depth analyses of metal properties and behaviors to technologies in application. The book provides a full c…
This paper presents the first electrochemical study of Ni(II) secochlorins, chlorophin, and homoporphyrins and demonstrates the influence of macrocycle-rigidity on the site of electroreduction. Oxidations and reductions were investigated by cyclic voltammetry. The measured electrode potentials were found to be depende…
Palladium colloid with a narrow particle size distribution is formed in the reduction of PdCl 4 2- by hydrogen in aqueous solution, using sodium citrate as stabilizer. The absorption spectrum of the Pd particles depends on their content of chemisorbed hydrogen atoms. In the absence of hydrogen, the absorption maximum…
Diatoms are a key component of marine ecosystems and are extremely important for the biogeochemical cycling of silica and as contributors to global fixed carbon. However, the answers to fundamental questions such as what diatoms can sense in their environment, how they respond to external signals, and what factors con…
A CoFe Prussian blue analogue Rb 1.8 Co 4 [Fe(CN) 6 ] 3.3 ·13H 2 O was synthesized, which presents an important photomagnetic effect. The electronic structure and the local structure of the ground and of the excited states have been investigated. X-ray absorption spectroscopy measurements at the Co and Fe L 2,3 edges…
We have studied the competitive epoxidations of olefins with cis - and trans -stilbenes and with cyclooctene and trans -stilbene in iron porphyrin complex-catalyzed epoxidation reactions by H 2 O 2, tert -butyl hydroperoxide ( t -BuOOH), and m -chloroperoxybenzoic acid ( m -CPBA) in protic solvent (i.e., a solvent mix…
We present a theoretical approach to calculate the {\it local} absorption spectrum of excitons confined in a semiconductor nanostructure. Using the density-matrix formalism, we derive a microscopic expression for the non-local susceptibility, both in the linear and non-linear regimes, which includes a three-dimensiona…
We reported a systematic change in the average magnetic relaxation rate, after the application and removal of a 5 T magnetic field, in a polycrystalline sample of La0.5Ca0.5MnO3. Magnetic relaxation measurements and magnetization versus field curves were taken from 10 K to 160 K. The long time behavior of the relaxati…
Coiled-coil motifs provide simple systems for studying molecular self-assembly. We designed two 28-residue peptides to assemble into an extended coiled-coil fiber. Complementary interactions in the core and flanking ion-pairs were used to direct staggered heterodimers. These had "sticky-ends" to promote the formation…
A novel molecular triad, representing an artificial reaction center, was synthesized via linking a fullerene moiety to an array of two porphyrins (i.e., a zinc tetraphenyl porphyrin (ZnP) and a free base tetraphenyl porphyrin (H 2 P)). In this ZnP−H 2 P−C 60 triad, the ZnP performs as an antenna molecule, transferring…
A new experimental method is presented using fluorescein dye to determine the spatial and temporal variations of the liquid volume fraction in aqueous foams. This method is used for quantitative studies of liquid redistribution ( drainage ) in three types of experiments: forced, free, and pulsed drainage. Characterist…