Materials Literature
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Crystal structural parameters (21 positional parameters and nine isotropic Debye-Waller factors) of the intermediate phase of hexagonal barium titanate (h-BaTiO3) have been refined by a structure analysis method using convergent-beam electron diffraction (CBED); this method was developed by Tsuda & Tanaka [Acta Cryst.…
Nonoxidative activation of methane was carried out over Ag/ZSM-5 catalysts, prepared by the wetness impregnation method, and the catalysts were characterized by various techniques. Theoretical calculation was further employed to clarify the reaction mechanism of methane coupling over the catalysts. Ag + ions were foun…
We present a simple and computationally efficient classical atomistic model of silica in which the silicon and oxygen are simulated as hard spheres with four and two association sites, respectively. We have performed isobaric-isothermal Monte Carlo simulations to study the mechanical and phase behavior of this model.…
Very strong electronic communication, manifested in a K(C) value of ca. 10(9), has been found in a system of three compounds separated by one electron oxidation where each compound contains two metal-metal bonded Mo(2)(n+) units linked by a dimethyloxamidate anion, CH(3)N(O)C-C(O)NCH(3)(2)(-). The Mo-Mo distances incr…
The localized, sustained delivery of growth factors for wound healing therapy is actively being explored by gene transfer to the wound site. Biocompatible matrices such as bovine collagen have demonstrated usefulness in sustaining gene therapy vectors that express growth factors in local sites for tissue repair. Here,…
Abstract The new meta ‐oxoborates γ‐ RE (BO 2 ) 3 ( RE = La ‐ Nd) (≡ RE B 3 O 6 ) were obtained as colourless (La, Ce), light green (Pr) and pale violet (Nd) crystalline powders by the reaction of CeO 2 , Pr 6 O 11 , or RE 2 O 3 ( RE = La, Nd) and B 2 O 3 in a Walker‐type multianvil apparatus under high‐pressure/high‐…
Abstract The solid‐state structure and properties of homogeneous copolymers of propylene and 1‐octene were examined. Based on the combined observations from melting behavior, dynamic mechanical response, morphology with primarily atomic force microscopy, X‐ray diffraction, and tensile deformation, a classification sch…
This study introduces a new train of thought regarding the growth of well-arrayed nanowires. To reduce how defects such as grain boundary affect subsequent growth of the nanowires, the epitaxial buffer layer should be carefully chosen. The titanium nitride (TiN) buffer layer facilitates the growth not only of the arra…
We have developed carbon nanotube (CNT) vias consisting of about 1000 tubes. The total resistance of the CNT via was measured as three orders of magnitude lower than the current flows in parallel through about 1000 tubes. There is no degradation observed for 100 hours at the via current density of 2/spl times/10/sup 6…
Abstract The cluster compounds K 10 Zn 4 Sn 4 S 17 , K 10 Mn 4 Sn 4 S 17 , K 10 Fe 4 Sn 4 S 17 , K 10 Co 4 Sn 4 S 17 , Cs 10 Cd 4 Sn 4 S 17 and K 10 Zn 4 Ge 4 S 17 are described. The structures of these compounds, refined by single‐crystal X‐ray diffraction techniques, contain the discrete cluster [M 4 M′ 4 S 17 ] 10‐…
Abstract A multistage scheme has been developed for the structure prediction of viable clusters, where a genetic algorithm is implemented within the first stage to generate approximate structures that can be refined via direct energy minimisation techniques in a later stage. Inclusion and exclusion zones, regions of s…
Molecular beam scattering techniques were employed to investigate the adsorption/reaction of NO with an atomic oxygen covered Au(111) surface to form nitrogen dioxide, NO 2 . Results suggest that at temperatures above T s ≈ 200 K, the NO 2 production is limited by NO surface lifetime on O/Au(111); at temperatures belo…
The electronic structure and dielectric screening of finite-length armchair carbon nanotubes are studied in view of their technical applications. For this purpose, a self-consistent tight-binding method, which captures the periodic oscillation pattern of the finite band gap as a function of tube length, is applied. We…
We have synthesized thin multiwalled carbon nanotubes (t-MWNTs) using a catalytic chemical vapor deposition (CCVD) method with FeMoMgO catalyst. The number of tube walls were 2∼6 with the corresponding diameters of 3∼6 nm. We obtained high production yield of over 3000 wt % compared to the weight of the supplied catal…
Abstract Summary: The pyrazinoquinoxaline‐based conjugated polymers poly(2,7‐diphenylpyrazino(2,3‐ g )quinoxaline‐3,8‐diyl‐1,4‐phenylene) (PZQP) and poly(2,7‐diphenylpyrazino(2,3‐ g )quinoxaline‐3,8‐diyl‐2,5‐thiophene) (PZQT) have been synthesized and characterized. PZQP and PZQT have optical band gaps of 2.44 and 1.7…
Abstract Correlations among the three components, δ d 2 (dispersion), δ h 2 (hydrogen‐bonding), and δ p 2 (polar) that make up the Hansen solubility parameter equation, δ o 2 = δ d 2 + δ h 2 + δ p 2 , have been analyzed for a large number of organic solvents. A relationship is found that enables δ h and δ p to be esti…
The $\mathrm{Sr}$ and $\mathrm{SrO}$ monolayers on $\mathrm{Si}(001)$ and the ${\mathrm{SrTiO}}_{3}∕\mathrm{Si}(001)$ interface have been simulated by means of total energy minimization within the density functional theory formalism and the generalized gradient approximation form of exchange-correlation potential. It…
The amphiphilic and self-polymerizable monomer 1,8-dihydroxymethyl-1,3,5,7-octatetrayne (DHMOTY) was prepared and dispersed in water by itself or with the help of phenyl trimethylamine hydroxide. Accordingly, cross-linked poly(1,8-dihydroxymethyl-1,3,5,7-octatetrayne) (polyDHMOTY) nanospheres were produced due to spon…
Au(2)H(-) was recognized and confirmed as a minor contamination to typical photoelectron spectra of Au(2) (-), produced by laser vaporization of a pure Au target using an ultrahigh purity helium carrier gas. The hydrogen source was shown to be from trace H impurities present in the bulk gold target. Carefully designed…
Abstract Recent developments in the field of solid state synthesis have given us access to synthesis conditions that range from effective negative pressures of about ‐1 GPa to high positive values exceeding 10 or even 100 GPa. Thus, it becomes necessary to explore not only the landscape of potential energy, but also t…