Materials Literature
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The charge density distribution has been determined for a transition metal cyanide, RbMn[Fe(CN)(6)], by means of the maximum entropy-Rietveld method combined with the highly angularly resolved synchrotron radiation x-ray powder diffraction at SPring-8 BL02B2. We directly observed a charge transfer from the Mn site to…
Reduction of the interfacial friction for the contact of a silicon oxide surface with sodium borosilicate in aqueous solutions has been accomplished through the adsorption of poly(L-lysine)-graft-poly(ethylene glycol) on one or both surfaces. Spontaneous polymer adsorption has been achieved via the electrostatic attra…
Three unsymmetrical ditopic hexadentate ligands coded for the recognition of trivalent lanthanide ions have been synthesized, L(AB), L(AC), and L(BC), where A represents a benzimidazole-pyridine-benzimidazole coordination unit, B a benzimidazole-pyridine-carboxamide one, and C a benzimidazole-pyridine-carboxylic acid…
Getting under the surface of aging: The bulk structure of copper nanoparticles can be tailored during the preparation by exploiting known structure–activity relationships. Ageing of freshly precipitated precursors leads to characteristic phase transitions and enables control of microstrain and particle size (see pictu…
We present a unified view of the transport properties of small polarons in the Holstein model at low carrier densities, based on the dynamical mean-field theory. The nonperturbative nature of the approach allows us to study the crossover from classical activated motion at high temperatures to coherent motion at low te…
The Protein Data Bank (PDB; http://www.pdb.org) is the primary source of information on the 3D structure of biological macromolecules. The PDB's mandate is to disseminate this information in the most usable form and as widely as possible. The current query and distribution system is described and an alpha version of t…
Temperature dependence of blinking in SERS (surface enhanced raman scattering) signal, which is abrupt repeated intensity and peak frequency fluctuation, was studied. It was found that the blinking observed at room temperature (RT) was suppressed by cooling to 77 K for one-third to one-fourth of the particles and reco…
Hierarchical self-assembly: Oligo(p-phenylenevinylene)s with pendant diamino triazine moieties can self-assemble through hydrogen-bonding interactions to give hexameric rosettes (see picture, left). These rosettes further organize into large supramolecular tubules (right) with perfect space filling.
Ultrathin films of polystyrene were deposited on the surfaces of carbon nanofibers using a plasma polymerization treatment. A small percent by weight of these surface-coated nanofibers were incorporated into polystyrene to form a polymer nanocomposite. The plasma coating greatly enhanced the dispersion of the nanofibe…
The Macromolecular Structure Database (MSD) group (http://www.ebi.ac.uk/msd/) continues to enhance the quality and consistency of macromolecular structure data in the Protein Data Bank (PDB) and to work towards the integration of various bioinformatics data resources. We have implemented a simple form-based interface…
Recent theoretical work suggested the possibility of constructing a super-resolution diffraction-free lens by using a negative refractive index medium (NRIM). The key proposition is that evanescent waves can be greatly enhanced by increasing the thickness of the NRIM. We report here experimental evidence that confirms…
The charge doped into a semiconductor in a field effect transistor (FET) is generally confined to the interface of the semiconductor. A planar step at the interface causes a potential drop due to the strong electric field of the FET, which in turn is screened by the doped carriers. We analyze the dipolar electronic st…
We report on the photodetecting properties of a ZnO-based thin-film transistor (TFT) that has been fabricated on a SiO2/p-Si substrate by rf magnetron sputtering at room temperature. Our ZnO-based TFT exhibited a saturation current level of about 6.5 μA under a gate bias of 40 V, decent electron mobility of 0.1 cm2/V…
We report a Raman scattering study of polycrystalline CaCu$_3$Ti$_4$O$_{12}$ (CCTO) under pressure up to 5.32 GPa. The pressure dependence of several Raman modes was investigated. No anomalies have been observed on the phonon spectra thereby indicating that the T$_{h}$ (Im$\bar 3$) structure remains stable for pressur…
The electronic band structure of yttrium sesquicarbide Y2C3(Pu2C3 structural type) reported by Akimitsu et al. (2003) as a novel 18-K superconductor is investigated using the first-principle full-potential LMTO method and compared with those of yttrium mono- and dicarbide: cubic YC and 4-K superconductor YC2 (CaC2 str…
A high valent MnVO porphyrin dimer is prepared by peracid oxidation of an MnIII dimer under basic conditions at room temperature (see scheme; mCPBA=m-chloroperbenzoic acid). The addition of an acid to a solution of the MnVO complex results in quantitative dioxygen evolution. Water and/or hydroxide ions are the sourc…
Monolayer gold islands with a thickness of one or a few monolayers on an FeO(111) substrate are found to exhibit identical CO adsorption behavior as large gold particles (see picture). This result suggests that particle thickness does not play a significant role in CO adsorption, and therefore size effects seen for th…
BRENDA (BRaunschweig ENzyme DAtabase) represents a comprehensive collection of enzyme and metabolic information, based on primary literature. The database contains data from at least 83,000 different enzymes from 9800 different organisms, classified in approximately 4200 EC numbers. BRENDA includes biochemical and mol…
All materials undergo some degree of compaction or expansion when exposed to radiation. Multi-component materials are more susceptible to this effect than single-component materials (e.g., fused silica). Nonetheless, the much lower expansion characteristics of multi-component materials -- such as the ultra-low expansi…
Abstract The ultrasonic degradation of poly(vinyl acetate) (PVAc) solutions was carried out in dioxan at 25, 30, 35, 40, and 45 °C to investigate the effects of the temperature and solution concentration on the rate of degradation. The kinetics of degradation were studied by viscometry. The calculated rate constants i…