Materials Literature
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We compute the anharmonic shift of the phonon frequencies in MgB2, using density functional theory. We explicitly take into account the scattering between different phonon modes at different q-points in the Brillouin zone. The shift of the E2g mode at the Gamma point is +5 % of the harmonic frequency. This result come…
Optical absorption and transverse Kerr effect spectra, resistivity and magnetoresistance of La$_{1-x}$Sr$_{x}$CoO$_3$ ($x=0.15, 0.25, 0.35$) films have been studied. The temperature dependencies of the optical and magneto-optical properties of the films exhibit features, which can be attributed to the transition of th…
Extensive density-functional theory calculations, and taking into account temperature and pressure, afford a comprehensive picture of the behavior and interaction of oxygen and Ag(111), and provides valuable insight into the function of silver as an oxidation catalyst. The obtained phase diagram reveals the most stabl…
We describe experiments that probe the response to a point force of 2D granular systems under a variety of conditions. Using photoelastic particles to determine forces at the grain scale, we experimentally show that disorder, packing structure, friction and texture significantly affect the average force response in gr…
We demonstrate highly efficient spin injection at low and room temperature in an AlGaAs/GaAs semiconductor heterostructure from a CoFe/AlOx tunnel spin injector. We use a double-step oxide deposition for the fabrication of a pinhole-free AlOx tunnel barrier. The measurements of the circular polarization of the electro…
Dielectric studies are described aimed at providing an understanding of the charge storage and transport of an epoxy resin containing TiO/sub 2/ nanoparticles. Comparative results for conventionally filled composites are given, and the results discussed in terms of the underlying physics. It is shown that nanometric f…
The actuation of a single-wall carbon nanotube (CNT) mat, an electrically conducting polyaniline (PAn) film and a composite of these two materials has been investigated in NaNO 3 (1 M), NaCl (1 and 3 M) and HCl (1 M) solutions. The expansion and contraction patterns of the PAn, CNT and CNT/PAn samples are similar in t…
For electrical machine designers, core loss data are usually provided in the form of tables or curves of total loss versus flux density or frequency. These can be used to extract the loss coefficients of the core loss formulas. In this paper, three currently available formulas are discussed and compared with the loss…
A kinetic Monte Carlo method was used to simulate the diffusion of reptating polymer chains across the interface. A time-resolved fluorescence technique conjunction with direct energy transfer method was used to measure the extend of diffusion of dye labeled reptating polymer chains. The diffusion of donor and accepto…
Single-walled carbon nanotubes have been cyclopropanated under Bingel reaction conditions, and the functionalized nanotubes have been characterized by atomic force microscopy using "chemical tagging" techniques.
The recent accumulation of large amounts of 3D structural data warrants a sensitive and automatic method to compare and classify these structures. We developed a web server for comparing protein 3D structures using the program Matras (http://biunit.aist-nara.ac.jp/matras). An advantage of Matras is its structure simil…
In acidic solution between pH 6 and 2.5, protons react reversibly and selectively in the presence of preadsorbed oxygen at the sidewall of aqueous dispersed single-walled carbon nanotubes suspended in sodium dodecyl sulfate. This reactive complex, which protonates the nanotube sidewall, reversibly diminishes absorptio…
Recent demonstrations of negative refraction utilize three-dimensional collections of discrete periodic scatterers to synthesize artificial dielectrics with simultaneously negative permittivity and permeability. In this paper, it is shown that planar, two-dimensional L-C transmission line networks in a high pass confi…
In addition to alkanethiols and phosphine derivatives, alkylamines have been investigated as capping agents in the synthesis of organically dispersible gold nanoparticles. However, reports pertaining to gold nanoparticle derivatization with alkylamines are relatively scarce and their interaction with the underlying go…
Left-handed (LH) materials, first introduced theoretically in Veselago (1968), have spurred considerable excitement since the demonstration of their practical realizability. The unique properties of these metamaterials, verified by full-wave analysis in Caloz et al. (2001), are promising for a diversity of optical/mic…
We observe infrared laser excited photoconductivity from a single carbon nanotube incorporated as the channel of an ambipolar field-effect transistor (FET). Electron−hole pairs are generated within the nanotube molecule, and the carriers are separated by an applied electric field between the source and drain contacts.…
The chemical reduction of graphite oxide (GO) to graphite by either NaBH 4 or hydroquinone and also its surface modification with neutral, primary aliphatic amines and amino acids are described. Treatment of GO with NaBH 4 leads to turbostatic graphite that upon calcination under an inert atmosphere is transformed to…
The fortran program ESPript was created in 1993, to display on a PostScript figure multiple sequence alignments adorned with secondary structure elements. A web server was made available in 1999 and ESPript has been linked to three major web tools: ProDom which identifies protein domains, PredictProtein which predicts…
Double-decker phthalocyanine complexes with Tb3+ or Dy3+ showed slow magnetization relaxation as a single-molecular property. The temperature ranges in which the behavior was observed were far higher than that of the transition-metal-cluster single-molecule magnets (SMMs). The significant temperature rise results from…
SWISS-MODEL (http://swissmodel.expasy.org) is a server for automated comparative modeling of three-dimensional (3D) protein structures. It pioneered the field of automated modeling starting in 1993 and is the most widely-used free web-based automated modeling facility today. In 2002 the server computed 120 000 user re…