Materials Literature
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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…
Infrared spectra of natural, synthetic and heat treated orthopyroxene samples belonging to the enstatite-ferrosilite join were investigated in the range 70–1400 cm −1 . Correlations of the wavenumber shifts and line broadening systematics with the thermodynamic mixing properties were found. Wavenumber shifts of the hi…
Multifunctional molecular glasses are versatile tools for organic optoelectronics. Their optical waveguide properties are of increasing interest. By using photopatterned molecular azo glass gratings, optical waves within multilayer devices can be controlled, optically excited, and brought to resonance.
A new approach to one-dimensionally organize the quantum dot Au 55 (PPh 3 ) 12 Cl 6 is described by using poly(vinyl-pyrrolidone) (PVP) molecules as templates. AFM investigations indicate chemisorption of the nanoclusters at the surface of the polymers. Using Langmuir−Blodgett techniques, networks of cluster-loaded po…
This short paper summarizes the preparation and optical characterization of the Eu3+ (X=0.2,0.5,1.0,1.5 & 2.0 mol%) doped 60ZnO+20B2O3+(20-X) SiO2 glasses from the measurement of their excitation and luminescence spectra at the room temperature. Dependence of red emission performance upon the excitation wavelengths in…
The bonding of N(2) to the five-coordinate complexes [FeX(depe)(2)](+), X = Cl (1a) and Br (1b), has been investigated with the help of X-ray crystallography, spectroscopy, and quantum-chemical calculations. Complexes 1a and 1b are found to have an XP(4) coordination that is intermediate between square-pyramidal and t…
Moeloite is a new lead-antimony sulfosalt, Pb 6 Sb 6 S 14 (S 3 ), discovered in the Ceragiola marble quarry, near Seravezza town (Tuscany, Italy). Associated minerals are: sulphur, pyrite and enargite. It crystallizes as very thin needles and soft plumose aggregates of flexible thin fibres with a metallic lustre. Unde…