Materials Literature
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The X-ray crystal structure of a uridine vanadate-ribonuclease A complex has been determined at 1.3 A resolution. The resulting structure includes all 124 amino-acid residues, a uridine vanadate, 131 water molecules, and a single bound 2-methyl-2-propanol. Side chains of 11 surface residues showing discrete disorder w…
Films of Ti dioxide, mixed Ti–Ce oxide, and Ce dioxide were produced by reactive dc magnetron sputtering. Electrochemical lithiation was probed by chronopotentiometry, cyclic voltammetry together with optical transmittance recording, and impedance spectroscopy. Evidence was found for inserted electrons being accommoda…
Using ab initio methods, the position and the orientation of a CO 3 2- impurity in a hydroxyapatite lattice is studied. The CO 3 2- ion is oriented in a plane that makes an angle of 7° with the crystallographic c axis. The carbon atom and two oxygen atoms occupy positions close to the axis, whereas the third oxygen is…
The geometries and second-order nonlinear optical properties of the four conformers of donor−acceptor-substituted calix[4]arene molecules are investigated by means of semiempirical quantum-chemical techniques. The evolution of the second-order polarizability β is analyzed with respect to changes in conformation and th…
Diethylaminoethyl–chitin (DEAE–chitin) was synthesized by introducing DEAE groups onto the C(6)–OH in chitin. DEAE–chitin was N-deacetylated by heating in aqueous 10% sodium hydroxide containing sodium borohydride to prepare the diethylaminoethyl–chitosan (DEAE–chitosan). In addition, DEAE–chitin was quaternized with…
We report the Ni ${\mathrm{L}}_{2,3}$-edge magnetic circular dichroism (MCD) measurements of ferrimagnetic ${\mathrm{Zn}}_{\mathrm{x}}$${\mathrm{Ni}}_{1\mathrm{\ensuremath{-}}\mathrm{x}}$${\mathrm{Fe}}_{2}$${\mathrm{O}}_{4}$ (x=0.0, 0.26, 0.50, and 0.75). The Ni MCD asymmetry ratio was found to decrease with increasin…
We have investigated the order-disorder phase transition in Cu-Al-Be alloys close to the eutectic composition. X-ray diffraction measurements have been performed to characterize the ordered structure and to follow the evolution of the degree of long-range order with temperature. Results show that the transition is fir…
Quenching of Er/sup 3+/ ions by homogeneous energy-transfer upconversion in high-concentration erbium-doped silica glasses has been theoretically investigated, The results indicate that at Er/sup 3+/ concentrations of 1.0-2.0/spl middot/10/sup 26/ m/sup -3/ or below, the kinetic limit of strong migration is not reache…
Reflective twisted nematic displays where the output polarizer is eliminated are analyzed and demonstrated. The absence of the rear output polarizer has many advantages, including much higher brightness and higher resolution. In this article, we examine the solution space for the design of such reflective displays. Bo…
Abstract A systematic study has been made on the influence of doped rare‐earth metal ions (Er 3+ and Nd 3+ ) on the molecular interaction present in thin films fabricated from chitosan‐acetic acid solutions (chitosan/HAc). FT‐IR spectroscopy (including NIR, MIR and FIR) coupled with X‐ray photoelectron spectroscopy (X…
Equilibrium binding of Thermomonospora fusca E3, E4 and E5, the E3 binding domain (CBDE3), and Trichoderma reesei CBHI on Avicel PH102 and bacterial microcrystalline cellulose (BMCC) was studied. The maximum adsorption levels, Eb,m, for all four cellulases and the binding domain were 9–30 times higher on BMCC than on…
Regiorandom and regioregular head to tail coupled poly(3-butylthiophenes), poly(3-octylthiophenes) and poly(3-dodecylthiophenes) have been synthesized by direct oxidation of 3- n -alkylthiophenes using FeCl 3 as oxidant and by regiospecific dehalogenation of 2-bromo-3- n -alkylthiophenes. NMR characterizations indicat…
Monoecious, bisexual and unisexual clones of Achnanthes longipes were isolated from the Black Sea and studied in laboratory culture. Clones differed in their growth characteristics : in monoecious clones the cells formed tufted aggregations while in other clones they were more dispersed. Bisexual and unisexual clones…
All articles of this category 2,3,9,10-Tetrakis(3,3-dimethyl-1-butynyl)phthalocyanine and 2,3,9,10-tetramethoxyphthalocyanine were prepared by the condensation of a "half" phthalocyanine intermediate (prepared from 4,5-bis(3,3-dimethyl-1-butynyl)phthalonitrile or phthalonitrile) with phthalonitrile and 4,5-dimethoxyph…
We have studied the behavior of confined ultrathin films of a simple model system in which the fluid and wall particles were modeled as Lennard-Jones rare gas atoms by Monte Carlo simula-tions. We have used a new (Grand isoforce) statistical ensemble in these simulations, with which it is possible to simulate thin fil…
Cumene hydroperoxide (CHP) is normally produced by the cumene oxidation process. Severe fire and explosion incidents have occurred in oxidation and concentration processes due to the thermal instability of CHP. In this study, we used DSC and ARC thermal analysis techniques to measure the runaway thermokinetic data. Da…
Abstract— This paper analyses the validity of the fracture mechanics approach to hydrogen assisted cracking in metals on the basis of K ‐dominance over both the stress‐strain state and the accumulation of hydrogen in the fracture process zone. Stress‐strain assisted diffusion of hydrogen is considered as the rate cont…
One-dimensionally oriented thin crystals of a phenylene oligomer, p -sexiphenylene (6P), are grown on the poly( p -phenylene) (PPP) film prepared by the friction-transfer method. The 6P molecules tend to grow epitaxially on the (001) planes of alkali halides and the molecular axis is parallel to the <110> direct…
The effects of grain size on the tribological behavior of alumina were investigated. Alumina specimens with three different grain sizes, namely 4, 8, and 14 m, were used as pins and disks in a flat‐pin wear test in which the apparent contact area was maintained constant during the test. In contradiction with previousl…
The macroscopic magnetic properties of magnets strongly depend on the microscopic magnetisation processes and the microstructure of the magnets. Whereas ideally homogeneous magnetic materials exhibit a relatively simple and well understood magnetisation behaviour, more complex materials such as two phase composites or…