Materials Literature
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To improve the biocompatibility of silicon-based implantable micro- and nanodevices, and to tailor silicon surfaces for controlled cell immobilization, well-defined functional polymer-Si(111) hybrids, consisting of nearly monodispersed poly(2-hydroxyethyl methacrylate [P(HEMA)] with covalently coupled collagen and tet…
We constructed ultraviolet (UV) photodetectors using thin films of silicon nanoparticles as active media. The Si nanoparticle films are electrodeposited at room temperature on Si p-type substrates. Uniform silicon nanoparticles of 1-nm diameter are dispersed from Si wafers using electrochemical etching. The nanopartic…
Molecular dynamics simulations of model miscible polymer blends consisting of 1,4-polybutadiene (PBD) (slow component) and PBD chains with reduced or eliminated dihedral barriers (fast component) have been performed in order to study the influence of blending on segmental relaxation processes in the fast component. We…
Stoichiometric BaTiO3 ceramics fabricated from sol-gel-derived powders and sintered at temperatures ⩽1100°C are highly insulating and electrically homogeneous. At higher sintering temperatures, samples gradually lose oxygen and the conductivity increases as a consequence. The latter phenomena are very sensitive to the…
The coercive field $({E}_{c})$ of $\mathrm{Pb}({\mathrm{Zr}}_{0.55}{\mathrm{Ti}}_{0.45}){\mathrm{O}}_{3}$ film was experimentally observed showing a paraboliclike relationship with grain size $d$. The curvature of ${E}_{c}\ensuremath{-}d$ increased as the film thickness decreased. A phenomenological theory was develop…
The evolution of the domain structure in lead zirconate titanate ceramics in the course of polarization fatigue is investigated by piezoresponse force microscopy. It is found that fatigue results in a strong modification of the domain structure. The domain patterns initially consisting of mainly 180° domains split int…
Reduction of [(triphos)NiCl2] (1) with an excess of NaBH4 in THF produces the paramagnetic Ni(I) complex [(triphos)Ni(eta2-BH4)] (2). X-ray crystallography shows 1 to be a square-planar Ni(II) species in which the phosphine ligand is bidentate, whereas 2 has pseudotetrahedral geometry at the Ni(I) center, with a tride…
The time-dependent morphology development in a segmented polyurethane, which was prepared by the reaction of equimolar amounts of 1,4-phenylene diisocyanate ( p PDI) and poly(tetramethylene oxide)glycol of 〈 M n 〉 of 975 g/mol, was investigated. No chain extender was utilized during the synthesis, and the resultant mo…
We report the enhanced thermoelectric properties of PbTe alloyed with antimony telluride (Sb2Te3). The resistivities and absolute values of the Seebeck coefficient for PbTe alloyed with Sb2Te3 increase while the thermal conductivities decrease with rising temperature. A maximum figure of merit, ZT, of 1.17 has been ac…
Successful reconstruction of large-diameter blood vessel in humans has been demonstrated using the tissue engineering technique, but improvement in patency of small-diameter bioartificial vascular graft remains a great challenge. This study reports that granulocyte colony-stimulating factor (G-CSF) can enhance in vivo…
Polycrystalline nickel based superalloys are prone to grain boundary attack by atmospheric oxygen either in the form of time dependent intergranular cracking during dwell time within a low cycle fatigue loading spectrum, known as hold time cracking, or in the form of intercrystalline oxidation at higher temperatures.…
This paper provides an overview of the mechanisms of high frequency (HF) loss in shielded power cables and discusses the challenges in the measurements of cable material properties at HF.
In order to clarify thermodynamic relationships of the various phases of KNbO 3 , enthalpies of formation for cubic ( P m 3 m ), tetragonal ( P 4 m m ), orthorhombic ( B m m 2) and rhombohedral ( R 3 m ) phases of KNbO 3 were calculated using a plane-wave pseudopotential method within a density functional formalism. T…
Haloalkane dehalogenases are enzymes that catalyze the cleavage of the carbon-halogen bond by a hydrolytic mechanism. Genomes of Mycobacterium tuberculosis and M. bovis contain at least two open reading frames coding for the polypeptides showing a high sequence similarity with biochemically characterized haloalkane de…
We report a detailed density functional theory (B3LYP) analysis of the gas-phase H2O2 formation from H2 and O2 on Au3, Au4+, Au5, and Au5-. We find that H2, which interacts only weakly with the Au clusters, is dissociatively added across the Au-O bond, upon interaction with AunO2. One H atom is captured by the adsorbe…
We studied the supramolecular comb−coil block copolymers formed by stoichiometric complexations of an amphiphilic surfactant, dodecylbenzenesulfonic acid (DBSA), with the poly(2-vinylpyridine) (P2VP) blocks in a linear polystyrene- block -poly(2-vinylpyridine) (PS- b -P2VP) and a nonlinear block−arm star copolymer of…
We report the realization of a low-temperature aqueous pathway for the chemical synthesis of zinc oxide (ZnO) nanowires with low defect density and their room-temperature ultraviolet lasing behavior at low pump fluence. The concentration of solutes determined not only the size of individual nanowires, which influences…
A new synthesis procedure has been developed to prepare Au−Ag alloy nanoparticles inside glassy SiO 2 film matrix. Two successive overlapping coating layers were prepared on glass substrate using Au- and Ag-incorporated inorganic−organic hybrid silica sols, respectively. The concentrations of the Au and Ag (3 equivale…
Negative charge carrier transport has been investigated in the columnar mesophases of 2,3,6,7,10,11-hexahexylthiotriphenylene (HHTT), (the best-known conducting discotic liquid crystal because of its high bulk hole mobility) using the time-of-flight method. It was shown that fast electron transport takes place in the…
Alloy 22 (UNS N06022) is a Ni-Cr-Mo-W alloy developed for corrosion resistance in a variety of aggressive environments. Because of its excellent corrosion resistance, Alloy 22 was selected as a candidate container material for the disposal of high-level nuclear waste at the proposed repository at Yucca Mountain, Nevad…