Materials Literature
按标题、摘要、年份、主题和来源检索公开元数据。结果保留作者、摘要、分类与原始来源链接。
Electronic and structural properties of a hypothetical material, silicon nanotubes, are examined through first-principles calculations based on density functional theory. Even considering that Si nanotubes have never been observed, this paper attempts to establish the theoretical similarities between Si and C, like ba…
In metal nanoparticles the resonance wavelength of light-driven collective electron oscillations is determined by the particle shape. This shape dependence can be used for optical data storage by spectral coding. In this way the storage density can be increased by at least a factor of 5 compared with that for conventi…
Recent advances in the theory of polarization and the development of linear-scaling methods have revitalized interest in the use of Wannier functions for obtaining a localized orbital picture within a periodic supercell. To examine complex chemical systems it is imperative for the localization procedure to be efficien…
Size effects in cupric oxide nanocrystals, synthesized using a novel electrochemical route, having average diameters of about 4 and 6 nm, are probed by x-ray photoelectron spectroscopy. Cu---O bond ionicity was found to increase with reduction in nanocrystallite size. Formation of pure CuO phase was confirmed from x-r…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPhotoalignment of Liquid-Crystal SystemsKunihiro IchimuraView Author Information Chemical Resources Laboratory, Tokyo Institute of Technology, 4259 Nagatsuta, Midori-ku, Yokohama 226-8503, Japan Cite this: Chem. Rev. 2000, 100, 5, 1847–1874Publication Date (Web):April 15, 20…
The extracts of six plants selected on the basis of folk-medicine reports were examined for their antibacterial effects against eight pathogenic bacteria. The results showed that n-butanol extract of Calotropis procera proved to be the most effective against the bacteria tested using the paper disc diffusion method. T…
Macroscopic orientation of self-organized supramolecular polymeric materials has been demonstrated by oscillatory shear flow using in-situ small-angle X-ray scattering (SAXS). In the case when a homopolymer poly(4-vinylpyridine) and pentadecylphenol molecules are stoichiometrically complexed to form comb copolymer-lik…
A grafted weak polyelectrolyte brush has been prepared by the incorporation of one block of a diblock copolymer inside a latex particle. The preformed brush shows a maximum in its hydrodynamic layer thickness radius as a function of added salt. Beyond 0.025 M NaCl, the data can be fitted to the scaling relationship fo…
Phosphonate binding sites in guanidine and ammonium surface-functionalized silica xerogels were prepared via the molecular imprinting technique and characterized using solid-state 31 P MAS NMR. One-point, two-point, and nonspecific host−guest interactions between phenylphosphonic acid (PPA) and the functionalized gels…
We present a novel and simple method for generating micron-scale annular structures formed from polystyrene- b -poly(methyl methacrylate) (PS- b -PMMA) diblock copolymer on a silicon oxide substrate. This method is based on prewetting of the underlying substrate with a minor polar solvent before spin-casting of the di…
Thin films of polypyrrole (PPY) were deposited on alumina particles using hexanoic acid adsorbed on the particles as a template. The formation of the template on alumina was confirmed through studies of the adsorption of hexanoic acid at various pH values. The adsorption results could be fitted to the Langmuir adsorpt…
The methyltrioxorhenium(MTO)-catalyzed oxidation of silanes to silanols and the epoxidation of various olefins by aqueous 85% H(2)O(2) proceed in high yields and excellent product selectivities (no disiloxanes, diols) in the presence of the zeolite NaY. The oxidative species is located inside the 12-A supercages. This…
The synthesis and characterization of iron-containing MCM-41 porous silica using the exchange method of the template with the iron salts FeCl 3 ·6H 2 O and (Fe 3 Ac 6 O·3H 2 O)NO 3 is reported. Proper conditions under which the exchange reactions can be accomplished without destroying the lattice structure of the pare…
The synthesis and electrochemistry of a series of tetrathiafulvalene (TTF) and dithia-crown-TTF derivatives attached with one or two disulfide group(s) 7a-f are reported. The self-assembled monolayers (SAMs) of these TTF disulfides on gold were prepared and characterized by reflection-absorption infrared spectroscopy.…
In this work we have determined, on a series of 0.5% Pd/C catalysts, the palladium particle sizes by the following physical techniques: (i) X-ray diffraction (XRD) line broadening (LB) method, associated with the Rietveld method, (ii) small-angle X-ray scattering, and (iii) transmission electron microscopy. The cataly…
We have utilized X-ray absorption fine structure (XAFS) spectroscopy to investigate the local atomic and electronic structure of iron incorporated into electrodeposited nickel hydroxide films. We found that cathodic codeposition from a solution containing Fe(II) and Ni(II) ions results in iron occupying Ni lattice sit…
Brownian dynamics simulations of perfect dendrimers up to the sixth generation have been performed under the influence of simple shear flow. Hydrodynamic and excluded volume interactions have been taken into account explicitly. The onset of shear-thinning is observed to occur at lower shear rates for larger dendrimers…
We study the dynamics of the glass formers toluene and glycerol below the glass transition temperature T g by means of 2 H NMR techniques. Whereas for toluene a slow β-process is observed in dielectric spectroscopy, this process is not discernible in glycerol. We demonstrate that standard 1D and 2D NMR experiments can…
ADVERTISEMENT RETURN TO ISSUEPREVNoteNEXTLight-Scattering Study of a Zwitterionic Polycarboxybetaine in Aqueous SolutionAizhen Niu, Der-Jang Liaw, Hui-Chuan Sang, and Chi WuView Author Information Department of Chemistry, The Chinese University of Hong Kong, Shatin, N. T., Hong Kong; Department of Chemical Engineering…
The chemisorption properties of NO on the oxidized TiO 2 (110) surface have been investigated using both experimental and theoretical methods. The results of temperature-programmed desorption measurements indicate that for NO exposures less than 1.1 × 10 14 molecules/cm 2 NO adsorbs weakly and desorbs at ∼127 K. The t…