Materials Literature
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The analysis of the phase behavior of a smectic A (SA) elastomer reveals a nematic phase existing within a small temperature range below the isotropic state. Stress-optical measurements in the pretransformational regime of the isotropic state indicate smectic as well as nematic fluctuations yielding a critical exponen…
While theoretical and experimental efforts have thoroughly addressed microphase-ordered AB diblock copolymer blends with a parent homopolymer (hA or hB) or a second block copolymer, surprisingly few studies have considered comparable ABA triblock copolymers in the presence of hB or an AB diblock copolymer. In this stu…
The radial, circular, and axial components /spl sigma//sub r/, /spl sigma//sub /spl phi//, and /spl sigma//sub x/, of the residual stress tensor in amorphous wires made by quenching in rotating water are derived from the classical elasticity theory on the assumption that the density decreases from the wire surface (r=…
The second-order nonlinear-optical coefficients of CsLiB6O10 have been absolutely determined for visible-to-ultraviolet second-harmonic wavelengths. The measurements were made by use of the wedge technique at the fundamental wavelengths of 0.532, 0.852, and 1.064 µm. The following values were obtained: d36=0.92 pm/V a…
Nanocrystalline carbon films possessing a prevailing diamond character are deposited by a direct current glow discharge chemical vapor deposition method using a 9:91 vol % methane to hydrogen gas mixture. In the present work the evolution and properties of nanodiamond films deposited by this method onto silicon substr…
The water-gas shift (WGS) reactor is a key component in fuel processors, but existing WGS catalysts are unsuitable for transportation applications, since the iron-chrome catalysts used at high temperatures are relatively inactive, and the copper-based catalysts used at low temperature tend to degrade under the severe…
Aqueous solutions of boehmite and hydrofluoric acid (HF) were used to prepare homogeneous mixtures of alumina and aluminum fluoride. Calcination at temperatures as low as 1000°C resulted in the formation of well‐defined hexagonal‐shaped α‐alumina platelets. Containment of the aluminum fluoride by covering the calcinat…
Dynamic holographic gratings were investigated with thin films of polymer azobenzene liquid crystals by periodic induction of photochemical nematic-to-isotropic phase transition. On irradiation of writing beams (488 nm), multiple diffraction beams of a reading beam (633 nm) were immediately observed. The first-order d…
In order to determine the effects of hydrogen peroxide on electrochemical corrosion potential (ECP) of type 304 stainless steel (SUS304), ECPs were measured using a high temperature, high pressure water loop with polytetrafluoroethylene (PTFE) inner liner at controlled hydrogen peroxide concentration. It is observed t…
Porous layers fabricated by anodic etching of n-GaP substrates in a sulfuric acid solution were studied by electron microscopy and cathodoluminescence (CL) microanalysis. The morphology of porous layers was found to depend strongly upon the anodization conditions. When the etching process starts at the initial surface…
Immobilization of acid phosphatase (ACP) in mesoporous or, more generally, nanoporous silica has been accomplished via the sol-gel reactions of tetramethyl orthosilicate in the presence of ACP and of D-glucose (DG) as a nonsurfactant template, which is subsequently removed by water extraction after the formation of na…
The direct proportionality relation between the boson peak maximum in glasses ${\ensuremath{\omega}}_{b}$ and the Ioffe-Regel crossover frequency for phonons ${\ensuremath{\omega}}_{d}$ is established. For several investigated materials ${\ensuremath{\omega}}_{b}=(1.5\ifmmode\pm\else\textpm\fi{}0.1){\ensuremath{\omega…
The emission bands of the 4.2, 3.2 and 2.6 nm sized ZnS:Eu2+ nanoparticles are peaking at 670, 580 and 520 nm, respectively. The emission of the 4.2 nm sized nanoparticles originates from the recombination of the Eu2+-bound exciton, while the emission of the 3.2 and 2.6 nm sized nanoparticles is from the Eu2+ intra-io…
A crystallographic interpretation of a possible transition mechanism from the wurtzite to the NaCl type is given. For this purpose, different atoms in the structures of both types are replaced by like ones, resulting in lonsdaleite-type configurations and in cubic primitive lattices, respectively. The atomic arrangeme…
We present a systematic study on the adsorption of NO and CO in Cu−ZSM-5, using an ab initio embedded cluster methodology at the B3LYP level of theory. We found that the effects of the cluster size and Madelung potential are small for adsorption energies of CO and NO. For adsorption of CO, the calculated binding energ…
Carbon nanotubes (CNTs) are grown vertically aligned on Fe catalytic particles deposited on a silicon oxide substrate at temperatures ranging from 550 to 950 °C by thermal chemical vapor deposition of acetylene. All CNTs have a bamboolike structure in which the curvature of compartment layers is directed toward the ti…
The simultaneous interaction of methyl radicals (CH3) and atomic hydrogen (H) with the surface of amorphous hydrogenated carbon (a-C:H) films is investigated by using quantified radical beam sources. The growth and/or erosion of the films during the interaction of the H and CH3 radical beam with the surface is monitor…
PURPOSE: To assess the renal tolerance of 1.0 mol/L gadobutrol as an electrically neutral contrast agent at magnetic resonance (MR) imaging in patients with impaired renal function. MATERIALS AND METHODS: Twenty-one patients with impaired renal function were enrolled in this prospective randomized study and classified…
We have studied the feasibility of doped eutectic SbTe alloys for practical application in digital video recording (DVR) rewritable phase-change media for high-numerical-aperture (NA=0.85) and blue-wavelength (λ=405 nm) recording. Remaining issues such as thermal cross-erase in land/groove recording and the thermal st…
The present paper investigates the oxidation kinetics of BN-ZCM composite ceramics in the temperature range of 1473K-1773K. Oxidation experiments with powder and plates of BN-ZCM composite ceramics have been carried out in air. Oxidation kinetics, products and structures of BN-ZCM have been examined and discussed. The…