Materials Literature
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A chemical method for preparing cadmium sulfide nanocrystals over silica surfaces is reported. This is a one-step synthetic method involving the chemical degradation of alkyldithiocarbamato complexes of cadmium in the presence of submicrometric SiO 2 particles. The X-ray powder diffraction patterns of the SiO 2 @CdS n…
The changes in magnesium ferrite, MgFe 2 O 4, due to high-energy milling in a stainless steel vial have been investigated by Mössbauer spectroscopy, X-ray diffraction, electron microscopy, and thermal analysis. The milling process reduces the average crystallite size of MgFe 2 O 4 to the nanometer range. Prolonged mec…
An ultrathin composite film containing both polyoxometalate anion [PMo12O40]3− (PMo12) and a planar binuclear phthalocyanine, bi-CoPc, has been prepared by the electrostatic layer-by-layer self-assembly method. UV-vis measurements revealed regular film growth with each four-layer {PMo12/bi-CoPc/PSS/PAH} adsorption. Th…
This paper reports the synthesis, crystal structures, and magnetic properties of a series of lanthanide complexes with nitronyl nitroxide radicals of general formula [[Ln(III)(radical)(4)] x (ClO(4))(3) x (H(2)O)(x) x (THF)(y)] (1-4) and [Ln(III)(radical)(2)(NO(3))(3)] (5, 6) [Ln = La (compounds 1, 3, 5) or Gd (compou…
A double-chain alkyl lipid with an isoquinoline-containing headgroup was derived from l -glutamide. This worked as an organogelator in benzene, cyclohexane, a cyclohexanes−ethanol mixture, and so forth. Transmission electron microscope observation showed that the gelation was brought about through the formation of a f…
Understanding of the damping of fast magnetization precession in ferromagnetic materials is important for technological applications, in particular for the development of fast magnetic memories. We use first-principles electronic structures together with the model of ``breathing Fermi surface'' to calculate the magnet…
We report on an experimental study of adsorption isotherm of nitrogen onto porous silicon with noninterconnected pores open at one or at both ends in order to check for the first time the old (1938) but always current idea based on Cohan's description which suggests that the adsorption of gas should occur reversibly i…
Ab initio phonon calculations for the nonpolar reference structures of the (001), (110), and (111) ${\mathrm{PbZrO}}_{3}/{\mathrm{PbTiO}}_{3}$ [1:1] superlattices are presented. The unstable polar modes in the tetragonal (001) and (110) structures are confined in either the Ti- or the Zr-centered layers and display tw…
We present the first analytical study of stability loss and evolution of domain structure in inhomogeneous ferroelectric samples for exactly solvable model. The model assumes a short-circuited capacitor with two regions with slightly different critical temperatures Tc1 > Tc2, where Tc1-Tc2 << Tc1, Tc2. Even a tiny inh…
Catalysts comprising manganese-porphyrins carrying cyclodextrin binding groups are able to perform hydroxylations with substrate selectivity and regio- and stereoselectivity and high catalytic turnovers. The geometries of the catalyst/substrate complexes override intrinsic substrate reactivities, permitting attack on…
The microscopic mechanism leading to stabilization of cubic and tetragonal forms of zirconia (ZrO$_2$) is analyzed by means of a self-consistent tight-binding model. Using this model, energies and structures of zirconia containing different vacancy concentrations are calculated, equivalent in concentration to the char…
Strong enhancement of the two-photon absorption of organic molecules near silver nanoparticle fractal clusters has been observed and has been exploited to yield composite materials with very strong two-photon absorption and two-photon-excited fluorescence properties. Measurements on cluster films coated with chromopho…
A dithienylethene (DTE)-porphyrin (P)-fullerene (C(60)) triad molecule in which intramolecular photoinduced electron transfer is controlled by the photochromic DTE moiety has been prepared. Irradiation of the molecule with visible light gives the open form of the dithienylethene (DTEo). Excitation of the porphyrin giv…
We report the synthesis of the first well-documented example of a cyano-bridged single-molecule magnet. An assembly reaction parallel to that employed in producing the trigonal prismatic [(Me(3)tacn)(6)MnCr(6)(CN)(18)](2+) (Me(3)tacn = N,N',N"-trimethyl-1,4,7-triazacyclononane) cluster affords K[(Me(3)tacn)(6)MnMo(6)(…
A simple synthetic route for the preparation of high-quality CdSe/ZnSe core/shell nanocrystals without the use of any pyrophoric organometallic precursors is presented. Effective surface passivation of monodisperse CdSe nanocrystals is achieved by overcoating them with a ZnSe shell, applying zinc stearate as a zinc so…
The crystal structure of YgbM (EC1530) (Fig. 1), a glyoxylate induced protein from Escherichia coli, has been determined and refined to 1.63 Å by multiple-wavelength anomalous dispersion (MAD) method. YgbM is encoded by DNA bases 2862259–2863035 and belongs to a protein family of Pfam-B_7694.1 The gene is clustered wi…
Photochemical behavior of polyethylene, polystyrene and polymethylmethacrylate films containing dibenzoylmethanatoboron difluoride was investigated. It was observed that during UV irradiation of polyethylene films the monomer fluorescence of the complex (λ max=450 nm) transforms into excimer fluorescence (λ max=535 nm…
Designers employ a number of strategies in choosing material and processes. The choice can be based on engineering analysis, identifying candidates that best meet the mechanical, thermal, electrical and economic constraints of the design. It can be based on past experience, accessed through a questionnaire-based selec…
We define and prove properties of the consensus shape for a family of proteins, a protein-like structure that provides a compact summary of the significant structural information for a protein family. If all members of a protein family exhibit a geometric relationship between corresponding alpha carbons then that rela…
Magnetization, resistivity, thermal expansion, thermopower, and neutron powder diffraction data are presented for the perovskite manganite ${\mathrm{Pr}}_{0.7}{\mathrm{Ba}}_{0.3}{\mathrm{MnO}}_{3}.$ A distinct ferromagnetic insulating state, similar to that observed in the ${\mathrm{La}}_{0.88}{\mathrm{Sr}}_{0.12}{\ma…