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。
Nanocomposites of montmorillonite mineral with poly-4-vinylpyridinium salts (1,2-form) the quaternized ionene polymer (1,6-form) and poly-4-vinylpyridine (neutral form) have been synthesized and characterized. Only one macromolecular sheet of poly-4-vinylpyridinium polyelectrolyte or the quaternized polyelectrolyte en…
X-ray diffraction analysis demonstrated that a PEN film annealed from 160 to 260 °C crystallizes in the α crystal form while crystallization of PEN directly from the melt results in the β crystal form when T c > 200 °C and in the α form at lower T c . Infrared spectra from PEN samples containing α, β, and amorphous ph…
Spin dependent single electron tunneling in a ferromagnetic double junction is investigated theoretically in the limit of incoherent sequential tunneling. The junction consists of a small nonmagnetic metallic grain with discrete energy levels, which is connected to two ferromagnetic electrodes. We have developed a new…
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTPreparation of Macroporous Metal Films from Colloidal CrystalsPeng Jiang, Joel Cizeron, Jane F. Bertone, and Vicki L. ColvinView Author Information Department of Chemistry, Rice University Houston, Texas 77005 Cite this: J. Am. Chem. Soc. 1999, 121, 34, 7957–7958Public…
The reversibility, specificity, stability, and scaling of signal response to analyte mass were quantified for a porous silicon-based optical interferometric biosensor. The sensor system studied consisted of a thin layer (5μm) of porous silicon modified with Protein A. The system was probed with various fragments of an…
Vacuum emission of ballistic electrons from Au-SiO 2 -Si structures has been investigated for oxide layers of various thicknesses d ox = 13-500 nm. In particular for very thick layers and high field strength 5 MV cm -1 we measure electron energies up to 200 eV, that is 80% of the maximum ballistic drive energy E ball…
The photochromism of spiro[cyclohexadiene-indolines], the reversible bond cleavage at the spiro-carbon resulting in a colored merocyanine, is affected by solvent polarity. Photoexcited intramolecular charge transfer within the preserved spiro form of the molecule is favored in polar solvents, explaining the drop in me…
In this paper, a Stoner-Wohlfarth approach to magnetic hysteresis is used as a model for a ferromagnetic composite rod consisting of single domain `grains' with random orientations embedded in a non-magnetic matrix. The rod is considered to be under torsional stress, which means that the rod at each point on its outer…
Fourier transform-infrared studies have been carried out on the non-stoichiometric Ni-Zr substituted barium hexaferrite synthesized through the citrate precursor method. We observed approximately 30 bands, almost twice as many as reported for stoichiometric samples. These are attributed to the shifting of the vibratio…
The composite structure of glow peak 5 in LiF:Mg,Ti (TLD-100), has been investigated using optical bleaching by 310 nm (4 eV) light. The decay of composite peak 5 and the growth of peak 4 are described by two exponential components of the same mean lives for both peaks. Using computerized glow curve deconvolution and…
To date most of the microelectromechanical system (MEMS) devices have been based on silicon. This is due to the technological know-how accumulated on the manipulation, machining and manufacturing of silicon. However, only very few devices involve moving parts. This is because of the rapid wear arising from high fricti…
Micro-organisms such as bacteria and yeasts form CdS to detoxify toxic cadmium ions. Frequently, CdS particles formed in yeasts and bacteria were found to be associated with specific biomolecules. It was later determined that these biomolecules were present at the surface of CdS. This coating caused a restriction in t…
ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTA General Mechanism for CO Oxidation on Close-Packed Transition Metal SurfacesChangjun Zhang, Peijun Hu, and Ali AlaviView Author Information School of Chemistry The Queen's University of Belfast Belfast BT9 5AG, U.K. School of Mathematics and Physics The Queen's Unive…
The fabrication of micropatterned TiO2 films on deep UV patterned self-assembled monolayers (SAMs) of phenylsiloxane is described. The patterned SAM was immersed in an acidic, aqueous TiF62- solution to directly deposit crystalline TiO2 (anatase) onto both hydrophobic (masked) and hydrophilic (irradiated) surface regi…
Crystal structures of ethylene−vinyl alcohol copolymers (EVOH) with various vinyl alcohol (VA) compositions have been determined on the basis of the X-ray diffraction data measured for the uniaxially and doubly oriented sample specimens. The unit cells of EVOH with a VA content higher than 27 mol % are monoclinic of t…
A monolayer ultrathin film of nitro-containing diazoresin (NDR) was fabricated on mica via a self-assembly technique. The adsorption of NDR on mica at different deposition times was monitored by determining the absorbance of the NDR. It was confirmed that the deposition is rapid and reaches saturation within 2 min. Th…
Polystyrene- block -poly(2-vinylpyridine) with different block lengths, viz., 190−190 and 800−860 monomer units, have been employed in order to obtain monodisperse Au nanoparticles, dispersed in a polypyrrole (PPY) matrix. In consonance with optical absorption spectra, the formation of a nanodispersion of Au has been…
The unsymmetrical dithienylethene photochrome 1a exhibits proton-gated photochromic properties as well as novel chemical reactivity. The dimethoxylated derivative 9a represents a light-triggered proton switch whose dissociation constant is increased by a factor of 16 upon photochemical cyclization to 9b. Such compound…
The synthesis of semiconducting nanocrystals of manganese oxide of controlled sizes and their manipulation to form ordered arrays is described. Nanocrystalline mixed-valent manganese oxides have been prepared as colloidal solutions via reduction of tetraalkylammonium (methyl, ethyl, propyl, and butyl) permanganate sal…
Carbon nanotubes (CNTs) have been proposed as excellent materials for the construction of new, precisely tailored ultrafiltration membranes and as promising fibres for the construction of new, stronger composite materials. In this paper classical molecular dynamics simulations are used to investigate the potential use…