Materials Literature
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We have prepared hydrogenated single-wall and multiwall carbon nanotubes, as well as graphite, via a dissolved metal reduction method in liquid ammonia. The hydrogenated derivatives are thermally stable up to 400 °C. Above 400 °C, a characteristic decomposition takes place accompanied with the simultaneous formations…
We examine the behavior of the D-band feature in the Raman spectra of single-walled carbon nanotube (SWNT) bundles, observed between 1250 and $1450 {\mathrm{cm}}^{\ensuremath{-}1},$ as a function of the laser excitation energy. We used three SWNT samples with different diameters, and show that the D-band behavior of S…
The Raman spectra of a wide range of disordered and amorphous carbons have been measured under excitation from 785 to 229 nm. The dispersion of peak positions and intensities with excitation wavelength is used to understand the nature of resonant Raman scattering in carbon and how to derive the local bonding and disor…
beta-Ketoacyl-[acyl carrier protein (ACP)] synthase forms new carbon-carbon bonds in three steps: transfer of an acyl primer from ACP to the enzyme, decarboxylation of the elongating substrate and its condensation with the acyl primer substrate. Six residues of Escherichia coli beta-ketoacyl-ACP synthase I (KAS I) imp…
Three tetrameric cobalt(II)-pseudohalide complexes have been structurally and magnetically characterized. Compounds 1 and 2 are isomorphous and exhibit the general formula [Co2(dpk-OH)(dpk-CH3O)(L)(H2O)]2A2-4H2O where dpk = di-2-pyridyl ketone, L = N3(-) and A = BF4(-) for 1, and L = NCO(-) and A = ClO4(-) for 2. The…
Metal and oxygen core-level Auger and photoemission spectra have been measured for ultrathin epitaxial films of $\ensuremath{\alpha}\ensuremath{-}{\mathrm{Cr}}_{2}{\mathrm{O}}_{3}$ and $\ensuremath{\alpha}\ensuremath{-}{\mathrm{Fe}}_{2}{\mathrm{O}}_{3}$ on Pt(111). The binding-energy shifts of monolayer films relative…
Spiders spin multiple types of silks that are renowned for their superb mechanical properties. Flagelliform silk, used in the capture spiral of an orb-web, is one of the few silks characterized by both cDNA and genomic DNA data. This fibroin is composed of repeating ensembles of three types of amino acid sequence moti…
Anionic surface initiated polymerization (SIP) was investigated to improve the stabilities and grafting densities of polymers on clay. This is a challenge because of the difficulties with the anionic polymerization mechanism and the presence of adventitious H2O molecules in silicates and clay. Our results showed the l…
In this article, we report the fabrication of highly ordered TiO 2 nanowire arrays by anodic oxidative hydrolysis of TiCl 3 within a hexagonal close-packed nanochannel alumina (NCA). The single-crystalline anatase TiO 2 nanowires with diameters about 15 nm and lengths about 6 μm are obtained after annealing at 500 °C.…
Synchrotron-based high-resolution photoemission, conventional X-ray (Mg Kα) photoemission (XPS), X-ray absorption near-edge spectroscopy (XANES), and first-principles density-functional calculations have been used to study the electronic properties of a Ce 0.8 Zr 0.2 O 2 mixed-metal oxide. The results of density-funct…
X-ray diffraction study of multiwalled carbon nanotube (MWNT) grown by arc discharge in hydrogen atmosphere is presented. It is found that the thermal-expansion coefficient along the radial direction of MWNT is widely distributed in a range from $1.6\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}5} {\mathrm{K}}…
In our own work, we have recognized the benefits of Scheme 15 for the detection of mono-and bicyclic aromatic hydrocarbons. We have modified the rim of P-CD with an azamacrocycle, which ligates Eu3+ ion as the reporter site [405]. Tethered at only one nitrogen, the azacrown of 82 is able to swing away from the bottom…
The structures of the hexagonal Frank--Kasper phases F and K, which have been described in terms of the aggregation of clusters, are interpreted as modulated crystal structures. They are basically composed of two close-packed layers with ordered atomic vacancies rotated by 90 degrees to each other about their normal.
Following the explosion of Delta 241 (IIR-1) on January 17th, 1997, the failure investigation board concluded that the Graphite Epoxy Motorcases (GEM's) should be inspected for damage just prior to launch. Subsequent investigations and feedback from industry led to an Aerospace Corporation proposal to instrument the e…
Abstract Cadmium sulfide thin layers in polycrystalline solar cells are produced by chemical bath deposition (CBD). This process produces wastes containing ammonia and cadmium. These two chemicals must be recovered, and if possible recycled, from an environmental and economic point of view. A process has been implemen…
The crystal structure of a layered compound Sc(2)B(1.1)C(3.2), scandium boride carbide (M(r) = 140.43), has been re-refined as a commensurate composite crystal using 1795 single-crystal X-ray diffraction intensities with I > 2 sigma(I) collected by Shi, Leithe-Jasper, Bourgeois, Bando & Tanaka [(1999), J. Solid State…
We study the submonolayer diffusion of hard disks and rodlike molecules on smooth surfaces through numerical simulations and theoretical arguments. We concentrate on the behavior of the various diffusion coefficients as a function of the two-dimensional (2D) number density rho in the case where there are no explicit s…
Abstract A series of binary oxide‐supported ruthenium catalysts with zinc oxide as a component of the support was prepared. Zinc oxide was a major component of the support, the other component was lanthanum oxide, zirconium oxide, chromium oxide, barium oxide, gallium oxide, strontium oxide, calcium oxide or magnesium…
We present an optical study of the influence of both the flexoelectric effect and surface polarization on a hybrid-aligned nematic cell using the half-leaky guided mode technique. Tilt angle profiles, obtained from fits of experimental data (reflectivity curves) taken under applied voltages, are compared with the ones…
We have analyzed the experimental evidence of charge and orbital ordering in La0.5Sr1.5MnO4 using first principles band structure calculations. Our results suggest the presence of two types of Mn sites in the system. One of the Mn sites behaves as an Mn3+ ion, favoring a Jahn-Teller distortion of the surrounding oxyge…