Materials Literature
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We investigate the zero-temperature phase diagram and spin-wave properties of a double exchange magnet with on-site Hubbard repulsion. It is shown that even within a simple Hartree -- Fock approach this interaction (which is often omitted in theoretical treatments) leads to qualitatively important effects which are hi…
Abstract In contrast to λ-(BETS)2MCl4 (M = Fe, Ga) with superconducting (Ga) or π–d coupled antiferromagnetic insulating (Fe) ground states, λ-(BEST)2MCl4 (M = Ga, Fe) are semiconducting at ambient pressure despite of the close similarity of the crystal structures. There exists another triclinic modification of BEST c…
Interference in the Fresnel regime of periodic structures creates a wide variety of intricate diffraction patterns. The diffraction patterns from both amplitude and phase gratings can bear a strong resemblance to the grating itself, or have much more complex structures. In this paper, we discuss a general approach for…
Two quantum chemistry theoretical models in the gas phase at the density functional theory B3LYP/LACVP(d) level of calculation are proposed to rationalize the hydrazine oxidation by cobalt(II) phthalocyanine (Co(II)Pc). This oxidation reaction involves the net transfer of four electrons. These theoretical models that…
Influence of the vacancy concentration on the Li conductivity of the (Li(1-x)Na(x))(0.2)La(0.6)TiO(3) and (Li(1-x)Na(x)(0.5)La(0.5)TiO(3) perovskite series, with 0 < or = x < 1, has been investigated by neutron diffraction (ND), impedance spectroscopy (IS), nuclear magnetic resonance (NMR), and Monte Carlo simulations…
A stable trapped hydrogen atom in X-ray-irradiated beta-tricalcium phosphate (beta-Ca3(PO4)2, beta-TCP) was successfully detected at room temperature. This hydrogen atom is stable at ambient temperature for several months. Hyperfine structure of the hydrogen atom and superhyperfine structures of the two phosphorus ato…
A recently developed method of synthesizing organic−inorganic hybrid (nano)particles using a nonhydrolytic sol−gel route is reported. A range of silsesquioxane particles with diameters in the range ca. 0.1−2.0 μm has been prepared by reacting organotrichlorosilane precursors with dimethyl sulfoxide, used both as an ox…
Functionalization at the focal point of hyperbranched polyester was achieved using a series of amines and a postsynthetic reaction utilizing an activated p-nitrophenyl ester unit. An element of dense packing was also detected, as evident from differences in levels of incorporation between linear and bulky reagents.
3-Keto-l-gulonate 6-phosphate decarboxylase (KGPDC) and d-arabino-hex-3-ulose 6-phosphate synthase (HPS) are members of the orotidine 5'-monophosphate decarboxylase (OMPDC) suprafamily [Wise, E., Yew, W. S., Babbitt, P. C., Gerlt, J. A., and Rayment, I. (2002) Biochemistry 41, 3861-3869], a group of homologous enzymes…
We have found experimentally the IR-induced second harmonic generation (SHG) in glasses possessing different degrees of electron-phonon interactions. For the investigations, we have chosen As(1)(-)(x)()Bi(x)Te(3)-CaBr(2)-PbBr(2) (0 < x <1) glasses. General formalism is based on consideration of fifth-order nonlinear o…
We report a route to the fabrication of unique flowerlike polymer superstructures with uniform petals at the nanoscale. In this method, polymer/zeolite composite is first prepared by loading corresponding monomer and initiator into the channels of the host zeolite with the aid of supercritical (SC) CO2, followed by th…
A novel molecular based magnet of three-dimensional (3-D) cyanide-bridged bimetallic assembly, [{(323)Ni}3{FeIII(CN)6}2]n x 2nH2O where 323 = N,N'-bis(3-aminopropyl) ethylenediamine, was synthesized and structurally characterized. The compound crystallizes in the orthorhombic space group Pbca with a = 15.6560 A, b = 1…
Transient-state kinetics by its inherent nature can potentially provide more directly observed detailed resolution of discrete events in the mechanistic time courses of enzyme-catalyzed reactions than its more widely used steady-state counterpart. The use of the transient-state approach, however, has been severely lim…
Reverse Monte Carlo (RMC) modelling is now widely used for obtaining structural models of amorphous materials that are in quantitative agreement with available experimental structure data. In the case of ion conducting glasses it has been possible to determine the distribution and local environment of the mobile ions.…
We report a study of the displacive phase transition in SrTiO 3 using neutron total scattering with analysis by the reverse Monte Carlo method. The resultant configurations have been analysed in terms of bond distance and bond angle distribution functions, and using recently developed methods based on geometric algebr…
[reaction: see text] Four kinds of bispyridinio-appended gamma-cyclodextrin (gamma-CD) were prepared to make a molecular flask for controlling the stereoselectivity of photocyclodimerization of 2-anthracenecarboxylate. When the photocyclodimerization of 2-anthracenecarboxylate was carried out in the presence of A,E-bi…
Liquid anhydrous sulfuric acid forms molecular "shells" wrapped around single-walled carbon nanotubes (SWNTs). Temperature-dependent X-ray scattering from aligned acid-swollen fibers shows that crystallization of the bulklike acid surrounding the structured shells is templated by the aligned SWNTs, while the structure…
We have studied the compatibility of various catalysts for ethylene and ethanol chemical vapor deposition (CVD) syntheses of single-walled carbon nanotubes (SWNTs) on Si substrates. A strong selectivity between the catalyst elemental species and carbon source was found; SWNT yield for Fe (Co) catalysts was much higher…
Oxidized individual single-walled carbon nanotubes and amine polymers have been assembled into 11-32-nm-thick well-ordered conductive films. The films show highly anisotropic electrical conductivity, which is dominated by the nanotubes in the horizontal plane and by polymer-mediated tunneling in the vertical direction…
The peripheral functionalization of amine-terminated fourth-generation poly(amidoamine) (PAMAM) with thiophene dendrons and the preparation of dendrimer-encapsulated metal nanoparticles are described. Interesting nanoparticle stabilization and energy-transfer properties were observed with these hybrid materials. The s…