Materials Literature
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Silica mesoporous thin films have been synthesized with a self-assembling process using cetyltrimethylammonium bromide as an organic template and tetraethyl orthosilicate as the silica source. Mesoporous films with Pm 3 n cubic phase have been obtained and the films have been thermally treated in air with a progressiv…
Lattice parameters and the structural phase transition of La(0.68)(Ti(0.95),Al(0.05))O(3) have been investigated in situ in the temperature range 301-689 K by the synchrotron radiation powder diffraction (SR-PD) technique. High-angular-resolution SR-PD is confirmed to be a powerful technique for determining precise la…
Collagen prolyl 4-hydroxylases catalyze the hydroxylation of -X-Pro-Gly- sequences and play an essential role in the synthesis of all collagens. They require Fe(2+), 2-oxoglutarate, molecular oxygen and ascorbate, and all vertebrate collagen prolyl 4-hydroxylases are alpha(2)beta(2) tetramers. The alpha-subunits conta…
Theoretical spectra for the magneto-optical Kerr effect have been obtained for the Heusler-related alloys AuMnSb and AuMnSn, and repeated calculations are performed for the isostructural PtMnSb phase. Using experimental lattice constants, our calculations predict a Kerr rotation exceeding −1° in the 0.5–0.8 eV region…
The epitaxial requirement for the selection of metastable arogonite among the polymorphs of calcium carbonate has been studied. Under calcite‐favorable conditions, the critical epitaxial strain with aragonite‐type inorganic substrates was found to be in the range 5–7 %. The Figure shows aragonite “fuzz” grown on SrCO…
The structural and electronic properties of Eu 3+ -doped Y 2 O 3 films coated on spherical alumina nanoparticles are studied using transmission electron microscope, x-ray diffraction, and laser spectroscopic techniques. It is observed that the coated films crystallize at temperatures higher than 600°C and may be compl…
We examine the linear elasticity of the bcc and gyroid phases of block copolymer melts with self-consistent field theory (SCFT). Linear elastic moduli for single crystals are predicted by calculating the free energies for slightly deformed crystal structures. Predicted Voight and Reuss bounds for the shear modulus of…
Abstract A series of novel rod–coil diblock copolymers on the basis of mesogen‐jacketed liquid‐crystalline polymer were successfully prepared by atom transfer radical polymerization from the flexible polydimethylsiloxane (PDMS) macroinitiator. The hybrid diblock copolymers, poly{2,5‐bis[(4‐methoxyphenyl)oxycarbonyl]st…
Single-crystalline diamond nanoparticles (∼5 nm in scale) have been deposited onto molybdenum needles (with radii <100 nm), and their effects on field emission behavior were measured. Combined transmission electron microscopy observations, field emission measurements, and diamond depositions allowed for direct…
Transparent sol-gel hybrid films doped with erbium tris 8-hydroxyquinoline were prepared using methyltriethoxysilane, vinyltriethoxysilane, and phenyltrimethoxysilane as precursors. We obtain a strong 1.53-μm Er3+ luminescence with a wide full width at half-maximum and no thermal quenching. Comparison of absorption of…
The adsorption of long flexible chains from dilute solution is studied by Monte Carlo simulation of a coarse-grained bead-spring model, and the results are interpreted in terms of phenomenological theories, using both mean field approaches and scaling concepts. It is shown that the surface excess, i.e., the integral o…
A series of Pb(Zr,Ti)O3 (PZT) films with tetragonal/rhombohedral multilayered structures has been grown on Pt/TiO2/SiO2/Si substrates by rf magnetron sputtering at a relative low temperature. All the films comprise 12 periodicities of Pb(Zr20Ti80)O3/Pb(Zr80Ti20)O3 in constant thickness of 40 nm, but the layer thicknes…
Multilayer VOx films are reported to improve the infrared (IR) detecting characteristics for application as an IR active layer in a microbolometer. Multilayer VOx films formed from the V2O5/V/V2O5 thin film structure showed some advantages in electrical property control and more effective formation of typically unstab…
Recent experiments have found a bent-core liquid crystal in which the layer chirality alternates from layer to layer, giving a racemic or "antichiral" material, even though the molecules are uniformly chiral. To explain this effect, we map the liquid crystal onto an Ising model, analogous to a model for chiral order i…
Glucose isomerase from Streptomyces rubiginosus was crystallized in two forms: I222, with one molecule of 44 kDa in the asymmetric unit, and P2(1)2(1)2, with two unique molecules. The I222 structure is known, but the P2(1)2(1)2 form has not been solved before. X-ray diffraction data for the P2(1)2(1)2 form were collec…
Study of the hexameric and allosterically regulated citrate synthases (type II CS) provides a rare opportunity to gain not only an understanding of a novel allosteric mechanism but also insight into how such properties can evolve from an unregulated structural platform (the dimeric type I CS). To address both of these…
The hydrolysis of a phosphate ester can proceed through an intermediate of metaphosphate (dissociative mechanism) or through a trigonal bipryamidal transition state (associative mechanism). Model systems in solution support the dissociative pathway, whereas most enzymologists favor an associative mechanism for enzyme-…
FeCo−SiO 2 nanocomposite films on silica glass substrates were prepared by the sol−gel method and characterized by X-ray diffraction, transmission electron microscopy, Rutherford backscattering spectrometry, extended X-ray absorption fine structure spectroscopy, and magnetic susceptibility measurements. FeCo alloy nan…
Thin films of poly(bisphenol A- co -decane) (BA-C10) were isothermally crystallized at different temperatures. The lamellar structures and branching during crystallization were observed in real time at different temperatures by an atomic force microscope equipped with a high-temperature heater accessory. Our observati…
The electron-stimulated production of ${\mathrm{D}}_{2}$ from amorphous solid ${\mathrm{D}}_{2}\mathrm{O}$ deposited on Pt(111) is investigated as a function of film thickness. The ${\mathrm{D}}_{2}$ yield has two components that have distinct reaction kinetics. Using isotopically layered films of ${\mathrm{H}}_{2}\ma…