Materials Literature
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Using finite difference calculations in continuum equations and using deterministic kinetic equations for calculations in a discrete lattice, the problem of the asymmetry, related to the strong concentration dependence of the diffusion coefficient in the diffusional mixing of binary multilayers, was investigated assum…
Previous studies have reported the existence of a green photoluminescence (PL) band in oxygen-deficient silica glass when exposed to ultraviolet (UV) light. Oxygen deficient defects (Eδ′) were thought to be the origin of this PL band. In this article, we describe the characteristics of a green PL band in oxygen-surplu…
Crystals of triglycine sulphate (TGS) doped with orthonitroaniline (ONA) irradiated with different doses of gamma-radiation were used to investigate gamma-radiation effect on electrical and optical parameters. The absorption coefficient and the reflectance were measured and hence the extinction coefficient, the optica…
The electrical behavior of commercial ZnO varistor devices has been examined with voltage contrast microscopy and point contact dc electrical measurements. Nonlinear voltage‐dependent behavior has been observed across both of the major crystalline boundary types present in the system: Bi 2 O 3 layer containing ZnO gra…
Three novel quaternary selenoarsenates could be synthesized by the solventothermal reaction of [AsSe 3 ] 3 - anions with AgBF 4 in the presence of the respective alkali metal cation. Orange crystals of K 3 AgAs 2 Se 5 ·0.25MeOH ( I ) are formed after reaction in MeOH at 130 °C for ∼2 h. Its structure is built up of ψ-…
Abstract The title compound, a new terphenoquinone derivative, shows a dynamic redox behavior upon cyclic voltammetry and a reversible, photochemical-thermal isomerization between the quinone and diradical forms, both phenomena involving restricted conformational change.
This work studies the ternary Si-C-N phases ${\mathrm{SiC}}_{2}{\mathrm{N}}_{4}$ and ${\mathrm{Si}}_{2}{\mathrm{CN}}_{4},$exploiting an analogy between the NCN and O groups. Starting from the molecular model of ${N,N}^{\ensuremath{'}}\ensuremath{-}\mathrm{bis}(\mathrm{trimethylsilyl})\ensuremath{-}\mathrm{carbodiimide…
Poly(3-hydroxyalkanoate)-g-poly(ethylene glycol) crosslinked graft copolymers are described. Poly(3-hydroxyalkanoate)s containing double bonds in the side chain (PHA-DB) were obtained by co-feeding Pseudomonas oleovorans with a mixture of nonanoic acid and anchovy (hamci) oily acid (in weight ratios of 50/50 and 70/30…
Serendipity has been a major player in most dye discoveries, and phthalocyanines are no exception. The true account of their discovery in 1928 is given using information provided by one of the individuals involved (Ron Greig). One of the inventors, Drescher, after making a key observation as to the nature of the insol…
It has been shown before by (31)P NMR that Ras bound to the nonhydrolyzable GTP analogue guanosine 5'-O-(beta, gamma-imidotriphosphate) (GppNHp) exists in two conformations which are rapidly interconverting with a rate constant of 3200 s-1 at 30 degrees C [Geyer, M., et al. (1996) Biochemistry 35, 10308-10320]. Here w…
Abstract Mechanisms by which organic bases are adsorbed on hydrated smectite surfaces were investigated. Three Ca-saturated reference smectites (Otay, SPV, and Panther Creek) were dispersed in distilled water containing 5 μmol of pyridine or 3-butylpyridine. The pH was adjusted to between 7.5 and 3 using 0.01 M HCl. A…
Infrared spectroscopy is used to investigate the electronic structure and charge carrier relaxation in crystalline films of ${\mathrm{CrO}}_{2}$ which is the simplest of all half-metallic ferromagnets. Chromium dioxide is a bad metal at room temperature but it has a remarkably low residual resistivity $(<5 \ensurem…
Abstract Some A 2 + B 3 and A 3 + B 3 reagent pairs have been used for the direct polyamidation reaction leading, besides the network formation, to hyperbranched aramid structures. Depending on the chosen experimental conditions, variable amounts of a sol fraction having close similarities with the hyperbranched arami…
As type IX collagen is a minor cartilage component, it is difficult to purify sufficient amounts of it from tissues or cultured cells to study its structure and function. Also, the conventional pepsin digestion used for fibrillar collagens cannot be utilized for purifying type IX collagen, because it contains several…
Fumed silica is a synthetic amorphous silicon dioxide produced by burning silicon tetrachloride in an oxygen-hydrogen flame. Surface areas range from 50 up to 400 m2/g. Using particle sizing techniques, fumed silica shows micro-sized particles leading to surface areas markedly lower than expected. Fumed silica appears…
Four kinds of polyetherimides with different diamines were prepared and used to improve the toughness of bismaleimide resins composed of bis(4-maleimidediphenyl)methane and o,o′-diallyl bisphenol A. Dynamic mechanical analysis and scanning electron microscopy were used to characterize the phase structure of the modifi…
To elucidate the process and mechanism of the prograde conversion of saponite to chlorite through corrensite, the microstructures of a series of chlorite-smectite (C-S) mixed-layer samples from Kamikita, northern Japan were examined by high-resolution transmission electron microscopy using both lattice and structure i…
Optical spectroscopy and theory demonstrate that photon excitation of the positively charged anion vacancies ${(F}^{+}$ centers) at 5.0 eV in neutron-irradiated MgO crystals releases holes that are subsequently trapped at V-type centers, which are cation vacancies charge compensated by impurities, such as ${\mathrm{Al…
Instead of the conventional sol‐gel process in which heat treatment is used to form a dense composite film after dipping/withdrawing a substrate into/from the sol, a new sol‐gel process incorporating ultraviolet (UV) irradiation at ambient temperature has been attempted to improve the alkaline corrosion resistance of…
In order to scale up medium-chain-length polyhydroxyalkanoate (mcl-PHA) production in recombinant microorganisms, we generated and investigated different recombinant bacteria containing a stable regulated expression system for phaC1, which encodes one of the mcl-PHA polymerases of Pseudomonas oleovorans. We used the m…