Materials Literature
按标题、摘要、年份、主题和来源检索公开元数据。结果保留作者、摘要、分类与原始来源链接。
The electronic energy band structure, density of states (DOS) and charge density contour of KNbO 3 in the paraelectric cubic phase have been studied using the full-potential linearized augmented plane wave method within the generalized gradient approximation for exchange and correlation. The band structure shows an in…
Carbon nanotubes have attracted great interdisciplinary interest because of their unique structure and properties. However, carbon-nanotube research is challenged by several problems, such as: i) mass production of material, ii) control of length, diameter, and chirality, and iii) manipulation for use in diverse techn…
Here we report the synthesis of vancomycin (Van)-capped Au nanoparticles (Au@Van) and their enhanced in vitro antibacterial activities. Au@Van presumably acts as a rigid polyvalent inhibitor of vancomycin-resistant enterococci (VRE). It also has unexpected activity against an E. coli strain. Our results suggest that g…
Abstract Using Slater–Koster tight‐binding calculations, we found that, due to the coexistence of the π–σ electron hybridization and the inter‐tube interactions, the electronic properties of the rope formed by small‐radius metallic zigzag single‐walled carbon nanotubes (SWNTs) have some unique characters: for the rope…
This article discusses the mechanism of nematic liquid crystal alignment in stretched porous polymer films. The polymer films were formed by extreme stretching of an isotropic porous polyolefin, such that the draw ratio was 12:1. A 6-μm-thick porous film with a high porosity coefficient of 92% revealed fine string-sha…
Abstract The Raman spectra of β‐GeS 2 , β‐GeSe 2 , and SnGeS 3 crystals have been investigated as a function of temperature (18 to 300 K) at ambient pressure, and as a function of hydrostatic pressure, up to 4.9 GPa, at room temperature. Our aim was to separate the phonon–excitation–driven (“explicit”) and the thermal…
Abstract Chalcogenide glasses belonging to the Ge x S 94 − x Bi 6 system (14 ≤ x ≤ 28.33 at%) have been prepared from high purity constituent elements. Thin films of the same materials have been deposited by vacuum thermal evaporation. Optical absorbance measurements have been performed on the as‐deposited films. The…
Once spilled into soils, dense nonaqueous phase liquids (DNAPLs) such as chlorinated solvents migrate deep into the subsurface because of their high density. Their downward migration typically continues until capillary forces balance gravitational forces or until essentially impermeable strata are reached. Efforts to…
The structure and morphology of nanosized Cu islands grown by sputter deposition on clean SiO2 substrates and Ti-underlayered SiO2 substrates are investigated using transmission electron microscopy. On SiO2, spherical Cu islands with a random crystalline orientation are formed, whereas on Ti/SiO2, semispherical island…
Transparent ferroelectric strontium–barium niobate (SBN) doped silica nanocomposites were prepared via a modified sol–gel process. Their structural properties were characterized by x-ray diffraction and Raman spectroscopy. It was found that by annealing the nanocomposites at temperatures between 600 and 800 °C, pure t…
A method to study temperature dependent thickness variation of thin films has been developed based on angle and energy dispersive x-ray reflectivity (EDR) techniques. The data analysis scheme developed for this method combines both energy and angle dispersive x-ray reflectivity (ADR) profiles. The ADR technique provid…
We study the phase resonances in metallic compound gratings. The diffraction problem is solved by means of the modal method and the surface impedance boundary condition. The response of gratings made of various metals is analysed. Curves of specular efficiency, field amplitude and phase inside the grooves are shown an…
The magnetic order resulting from an indirect exchange between magnetic moments provided by the spin-polarized hole gas in the metallic phase of a ${\mathrm{Ga}}_{1\ensuremath{-}x}{\mathrm{Mn}}_{x}\mathrm{As}$ double layer structure is studied via Monte Carlo simulation. The exchange is calculated to the second order…
Adsorption of ${\mathrm{NH}}_{3}$ and ${\mathrm{BBr}}_{3}$ (and their decomposed fragments) onto B and N sites of $c\ensuremath{-}\mathrm{BN}(111)$ and $h\ensuremath{-}\mathrm{BN}(101\ifmmode\bar\else\textasciimacron\fi{}0),$ has been theoretically investigated using DFT calculations under periodic boundary conditions…
Abstract Fluorescence measurements on Er ions in Y 2 O 3 thin films have been analyzed with crystal‐field Hamiltonians of C 2 and C 3 i symmetries including J ‐mixing effects. Crystal‐field parameters have been determined based on the Racah theory, that minimize the rms deviation between calculated and experimentally…
Abstract The temperature dependence of thermal, morphological, and rheological properties of amphiphilic polyurethanes was examined with differential scanning calorimetry (DSC), wide‐angle X‐ray scattering (WAXS), small‐angle X‐ray scattering (SAXS), rheological measurements, and Fourier transform infrared spectroscop…
Pt/(Ba 0.7 Sr 0.3 ) TiO 3 ( BST)/YBa 2 Cu 3 O 7− x (YBCO ) capacitors on SrTiO3 substrates were fabricated. The temperature and field dependence of the leakage current of Pt/BST interface were studied in the temperature range from 100 K to 320 K and in an electric field up to 3 MV/cm. For a middle electric field (&…
Molecular chirality, and the chiral symmetry breaking of resulting macroscopic phases, can be topologically imprinted and manipulated by cross-linking and swelling of polymer networks. We present a new experimental approach to stereo-specific separation of chiral isomers by using a cholesteric elastomer in which a hel…
Mechanisms of cross relaxation (3H4, 3H6→3F4, 3F4) in Tm3+ -doped PbO−Bi2O3−Ga2O3−GeO2 glass were analyzed. The energy gap between the absorption (3H6→3F4) and emission (3H4→3F4) spectra was approximately 600 cm−1. A large decrease in cross relaxation rates at low temperatures indicated that cross relaxation is contro…
Mechanical properties, such as flexural strength, fracture toughness and ductility, and superconducting properties, T c , J c and H irr , are crucial for industrial applications of high- T c oxide superconductors. However, oxide superconductors have the intrinsic brittleness of the perovskite structure, thus the stren…