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 up‐conversion photoluminescence (PL) in films of polyfluorene (PF) doped with metallated porphyrins is reported for the first time. The dependence of the up‐conversion process on the pump laser intensity and wavelength, the central metal moiety of the dopants, and the temperature is presented. Up‐conversion emissi…
We summarize our recent findings on how the current-driven magnetization switching in nanofabricated magnetic multilayers is affected by an applied magnetic field, changes of temperature, magnetic coupling between the ferromagnetic layers, variations in the multilayer structure, and the relative rotation of the layers…
This paper presents a theoretical study of the phenomenon of acoustic imaging by sonic crystals, which are made of two-dimensional regular arrays of rigid cylinders placed in parallel in air. The scattering of acoustic waves is computed using the standard multiple scattering theory, and the band structures are compute…
In this work we develop theoretical and numerical methods of calculation of a dynamic friction coefficient. The theoretical method is based on an adiabatic approximation which allows us to express the dynamic friction coefficient in terms of the time integral of the autocorrelation function of the force between both s…
We describe the use of self-assembled films of thiolated (dT)25 single-stranded DNA (ssDNA) on gold as a model system for quantitative characterization of DNA films by X-ray photoelectron spectroscopy (XPS). We evaluate the applicability of a uniform and homogeneous overlayer-substrate model for data analysis, examine…
Starting from the assumption that ferromagnetically correlated regions exist in manganites even in the absence of long-range magnetic order, we construct a model of charge transfer due to the spin-dependent tunnelling of charge carriers between such regions. This model allows us to analyze the temperature and magnetic…
We report absolute values for the radiative relaxation quantum yield of synthetic eumelanin as a function of excitation energy. These values were determined by correcting for pump beam attenuation and emission re-absorption in both eumelanin samples and fluorescein standards over a large range of concentrations. Our r…
We study domain patterns in cubic-tetragonal ferroelastics by solving numerically equations of motion derived from a Landau model of the phase transition, including dissipative stresses. Our system sizes, of up to ${256}^{3}$ points, are large enough to reveal many structures observed experimentally. Most patterns fou…
A biomolecule-assisted simple technique has been developed for the spontaneous ordering of the Bi2S3 nanorods into snowflakelike superstructures in high yield under microwave-hydrothermal conditions. In this method, glutathione (GSH) is used as both an assembling agent and a sulfur source. By controlling the molar rat…
Due to its high stacking fault energy, no deformation twin has ever been observed in coarse-grained Al. Recent molecular dynamic (MD) simulations predicted the formation of deformation twins in nanocrystalline (nc) Al. Here, we report transmission-electron-microscopic observations of two types of twins in nc Al proces…
Density-functional calculations for the (0001)-Zn surface of wurtzite ZnO are reported. Different stabilization mechanisms, such as metallization of the surface layer, adsorption of OH groups or O adatoms, the formation of Zn vacancies, and large scale triangular reconstructions are considered. The calculations indica…
An approach is presented for the atomistic study of phonon transport in real dielectric nanowires via Green's functions. The formalism is applied to investigate the phonon flow through nanowires coated by an amorphous material. Examples for a simple model system and for real Si nanowires coated by silica are given. Ne…
Remarkable surface wettability transition occurs with an inducement of ultraviolet (UV) for aligned ZnO nanorod films. The inorganic oxide films, which show super-hydrophobicity (left), become super-hydrophilic (right) when exposed to UV illumination. After the films are placed in the dark, the wettability evolves bac…
The dielectric dispersion of the solid solutions (Pb 1- x Ba x )(Zn 1/3 Nb 2/3 )O 3 and (Pb 1- x Sr x )(Zn 1/3 Nb 2/3 )O 3 with x =0.2 and 0.3 has been studied as a function of temperature for the frequency range 0.1 to 200 kHz. The variation in the relaxor nature between the studied compounds is discussed using the g…
Abstract Syndiotactic polystyrene (sPS) has various crystalline forms such as α, β, γ, and δ forms, and a mesophase depending on the preparation method. In this study, we focused on the mesophase with the molecular cavity of sPS, which is obtained by step‐wise extraction of the guest molecules from the sPS δ form. To…
Abstract Thermogravimetric analysis was used for a comparative investigation of the thermooxidative decomposition of ethylene vinyl acetate (EVA) copolymers with different vinyl acetate (VA) group contents. There were two stages of mass loss in this process. It was revealed that the apparent activation energies were c…
La modified Sr 0.8 Bi 2.2 Ta 2 O 9 (SLBT) thin films were fabricated on Pt/Ti/SiO 2 /Si substrates by metalorganic decomposition. All the films were annealed at 800°C using a rapid thermal annealing furnace. X-ray diffraction analysis indicated that single-phase layered perovskite SLBT ferroelectric thin films can be…
Abstract To suppress the repulsive interfacial energy between hydrophilic clay and a hydrophobic polymer matrix for polymer–clay nanocomposites, a third component of amphiphilic nature such as poly(ϵ‐caprolactone) (PCL) was introduced into the styrene–acrylonitrile copolymers (SAN)/Na‐montmorillonite system. Once ϵ‐ca…
The characteristics of Phenanthrenquinone (PQ) doped Polymethyl methacrylate (PMMA) for recording edge-illuminated holographic spectral filters for dense wavelength division multiplexing applications are evaluated. Filter design includes the effects of material absorption and apodization of the index profile. Rigorous…
Two new C-21 steroidal glycoside epimers, paniculatumosides A and B (1 and 2), based on a 13,14:14,15-disecopregnane-type skeleton, with neocynapanogenin B (3) and neocynapanogenin C (4) as two new aglycons, were isolated from the roots of Cynanchum paniculatum. Their structures were determined by spectral data interp…