Materials Literature
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The ability of CH3 groups to form helical chains of C–H‥π interactions with phenyl rings leads to polar stacking of trigonal octupolar networks in a substituted triazine, and therefore to three-dimensional non-centrosymmetry.
This paper is devoted to the study of resonant waveguide grating filters. It is shown that doubly periodic structures permit one to increase the angular tolerance of the filters without modifying the frequency linewidth. A theoretical study of such structures is presented and their response to an incident Gaussian bea…
A single chamber cell constructed from an yttria‐stabilized zirconia solid electrolyte with a nickel anode and a strontium‐doped lanthanum manganese oxide cathode can generate an electromotive force (emf) of and a power density of in a mixture of methane and air at a flow rate of and . The simultaneous additions of ga…
CdS (E=2.5 eV) nanoparticles were synthesized in reversed micelles and capped with materials of different band gaps and charge compensation ability: Cd(OH)2 (4.0 eV), ZnS (3.2 eV), and CdO (2.3 eV). The preparations allowed the examination and comparison of the efficiencies of confinement of the electron and hole by t…
The glnA gene in the domains Bacteria and Archaea encodes glutamine synthetase, a universally distributed enzyme that functions in ammonia assimilation and glutamine synthesis. We investigated the regulation and function of glnA in the methanogenic archaeon Methanococcus maripaludis. The deduced amino acid sequence of…
In contrast to normal conjugated oligomers, the stilbenoid squaraines 3a–d do not show a convergence of VIS/NIR absorption due to the extension of conjugation; the observed bathochromic effect in the beginning of the series is followed by a hypsochromic effect; this result seems to be characteristic for stilbenoid com…
An extremely fine active bending catheter devised for intravascular cerebral approaches is presented. A catheter with an outer diameter of /spl phi/1.5 mm and a total length of 1,500 mm has been developed. A shape memory alloy (SMA) wire is used as a bending actuator. In order to insert the catheter safely and rapidly…
Polymorphs of the charge transfer salt (bedt-ttf)4[(H3O)- CrIII(C2O4)3]·PhCN [bedt-ttf = bis(ethylenedithio)tetrathiafulvalene] which are either superconducting or semiconducting differ in the spatial distribution of Δ and Λ enantiomers of [Cr(C2O4)3]3– within the unit cell.
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTFormation of a Macrobicyclic Tris(disulfide) by Molecular Self-AssemblySuk-Wah Tam-Chang, Jeffrey S. Stehouwer, and Jinsong HaoView Author Information Department of Chemistry, University of Nevada, Reno, Nevada 89557 Cite this: J. Org. Chem. 1999, 64, 2, 334–335Publica…
Methods for iron loss reduction during manufacturing of wound-core distribution transformers are presented. More specifically, measurements taken at the first stages of core construction are effectively used, in order to minimize iron losses of transformer (final product). To optimally exploit the measurements (feedba…
IR spectroscopic results, combined with earlier crystallographic and spectroscopic evidence on Fe and Ru nitrosyl complexes, indicate that metastable η1-O and η2-NO linkage isomers are formed on low-temperature irradiation of the nitrosyl metalloporphyrins (OEP)Ru(NO)L (L = O-i-C5H11, SCH2CF3); the new compounds are s…
Phase transformation behaviour of the protonic layered tetratitanate, H2Ti4O9·nH2O, in air, water, methanol and ethanol has been investigated. H2Ti4O9·nH2O transformed in a series of steps to H2Ti8O 17 , monoclinic TiO2, anatase and rutile. All products retained fibrous morphology similar to that of K2Ti4O9 used as th…
Crystallization of the alkaline earth nitrates M(NO3)2·xH2O (M = Mg, x = 6; M = Ca, x = 4; M = Sr or Ba, x = 0) from an aqueous solution of either 15-crown-5 or 18-crown-6 resulted in complex formation in all cases. Thus, [Mg(H2O)2(15-crown-5)]3[NO3]6 and [Mg(H2O)5(NO3)]NO3·18-crown-6·H2O, [Ca(NO3)2(15-crown-5)], [Sr(…
The room-temperature high energy ball-milling technique was used to prepare nanophase Ce1-xZrxO2 (x=0; 0.2; 0.5; 0.8; 1) catalysts. The acid–base properties of these catalysts were investigated by means of adsorption microcalorimetry, using NH3 and CO2 as probe molecules. The catalytic activity for 4-methylpentan-2-ol…
La (1 – x) NiO (3 – δ) perovskites present high metallic conductivity and Pauli-paramagnetism, and could be used as electrodes in electrochemical devices such as SOFCs, PEMFCs and MCFCs. Additionally, due to its σ* conducting band, this material shows a very high electrocatalytic activity, particularly in oxygen reduc…
Silicate macroskeletons which have both templated mesoporosity and open-cell macrovoid structures have been prepared in monolithic form at near ambient temperatures from continuous metastable foams of non-ionic alkylpolyethylene oxide surfactants under aqueous, neutral pH reaction conditions.
In this work, standard characterization methods like hysteresis loops and C-V- measurements are used to distinguish the reversible and irreversible parts of the total ferroelectric polarization. Special attention has been given to the frequency dependence of the hysteresis loops-and the C-V-measurements. The frequency…
Abstract Soybean proteins recently have been considered as petroleum polymer alternatives in the manufacture of adhesives, plastics, and various binders. The objective of this work was to characterize the plastic performance of soybean protein components during molding processes. Two major soybean protein fractions, 7…
A new precursor technique for the carbothermal synthesis of nanocrystalline AlN powder has been developed. A precursor that contains an intimate mixture of nanocrystalline Al 2 O 3 and carbon has been synthesized by using a chemical pyrophoric reaction. The formation of AlN starts at 1473 K, and complete conversion ha…
Transition metal oxoborates are of interest for magnetic and optical properties. Crystals of many M II 2 M III O 2 BO 3 and M II M III OBO 3 materials can be grown from borate fluxes. In the Fe II -Fe III -B-O system, flux growth results in Fe 3 O 2 BO 3 crystals, but solid state reaction at higher temperatures has yi…