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。
Amorphous nitrogenated carbon films are prepared in a dual electron cyclotron resonance-radio frequency plasma from a mixture of methane and nitrogen gas. A marked variation of electronic properties and microstructure of the films as a function of nitrogen concentration is observed from Fourier transform infrared (FTI…
Ab initio electronic structure calculations, based on density-functional theory within the generalized gradient approximation, on ${\mathrm{LaSr}}_{2}{\mathrm{Mn}}_{2}{\mathrm{O}}_{7}$ are reported. The bulk electronic structure shows a gap in the minority-spin channel, while the Fermi energy lies at the bottom of the…
Anisotropic thermal diffusivity is examined in a cross-linked silicone elastomer deformed in simple elongation. Thermal diffusivity both parallel and perpendicular to the stretch direction is measured using an optical technique called forced Rayleigh scattering. The thermal diffusivity is found to increase linearly wi…
Acrylate monomers bearing side chains terminated in sulfur pentafluoride (−SF 5 ) groups have been synthesized. These monomers have been copolymerized into films with the conventional aliphatic acrylic monomer 2-hydroxyethyl methacrylate (HEMA) using neat cast mixed monomer films and photoinitiation. Depth-dependent s…
The frequency dependence of the interlayer conductivity of a layered Fermi liquid in a magnetic field that is tilted away from the normal to the layers is considered. For both quasi-one- and quasi-two-dimensional systems resonances occur when the frequency is a harmonic of the frequency at which the magnetic field cau…
Anionically polymerized six-arm star polystyrene samples with weight-average molecular weights M w of 5.6 × 10 4 −3.2 × 10 6 were studied by light scattering and viscometry in cyclohexane at different temperatures to determine their z -average mean-square radii of gyration (〈 S 2 〉 z ), second and third virial coeffic…
Radiative recombinations in amorphous ${\mathrm{Si}}_{1\ensuremath{-}x}{\mathrm{N}}_{x}:\mathrm{H}$-based nanometric multilayer structures have been studied by stationary and time-resolved photoluminescence measurements at room temperature. Such structures show higher photoluminescence efficiency than reference bulk a…
Ferroelectric BaTiO3 thin films have been fabricated on SrTiO3(001) substrate using pulsed laser deposition. In order to investigate the phase transition behavior of the thin films, we have conducted high-temperature x-ray diffraction in the process of heating and cooling. Lattice constants, degree of c-axis orientati…
The pressure–volume–temperature (P–V–T) properties of a number of metallocene-produced polyolefins were measured experimentally at 10 MPa ≤ P ≤ 200 MPa and 30°C ≤ T ≤ 220°C in a dilatometer-type P–V–T apparatus. These included ethylene copolymers typical of linear low density polyethylene, with several α-olefins as co…
Dumbbell-shaped ABA triblock copolymers composed of benzyl ether dendrons and polystyrene as the A and B blocks, respectively, were prepared using 2,2,6,6-tetramethylpiperidinyl-1-oxy (TEMPO) -mediated “living” free-radical polymerization. A new bis-dendritic unimolecular initiator, compound 3, was employed to study t…
The electrical transport properties of single-wall carbon nanotubes are shown to be strongly influenced by the presence of transition-metal impurities derived from the catalyst introduced to stimulate their growth. Data on thermoelectric power and electrical resistance in the temperature range 10--400 K were obtained…
The local structure around adsorbed carbon atoms on Ni(100) has been determined at low coverage as well as in the 0.5 monolayer $(2\ifmmode\times\else\texttimes\fi{}2)p4g$ ``clock'' reconstruction by scanned energy mode photoelectron diffraction. At low coverage, there is no radial strain of the Ni atoms surrounding t…
Ethylene−styrene interpolymers (ESIs) are viewed as random copolymers of ethylene and ethylene−styrene dyads. The amorphous ESIs offer an approach to characterizing polyethylene without the constraints imposed by the inevitable crystallinity. Large strain, nonlinear stress relaxation and recovery of ESIs were studied…
Nitrogenation for the intermetallic compounds such as MFe 2 (M = Ti, Zr, Nb, and Mo) or M‘Fe (M‘ = Ti and V) and the subsequent hydrogenation for the resulting interstitial metal nitrides were carried out to characterize their nitrogen storage properties by heating in a NH 3 −H 2 mixed gas or N 2 gas at 450−500 °C for…
The conduction behavior at high current density at room temperature and above of polyaniline (PANI) films doped with HCl and camphor sulfonic acid (HCSA), respectively, is reported. It is found that the current density deviates strongly from the linear relation with the electric field in high current density region, a…
Raman spectroscopy is applied to the study of the structure of polycrystalline silicon films. The analysis of the transversal optical phonon Raman line shows its complex structure consisting of two dominant contributions, centered at about 519 and 517 cm−1 and attributed to two dominant groups of grains with different…
Samples of poly( p -phenylene sulfide) obtained by different thermal and/or mechanical treatments are found to exhibit the same crystal structure. Conformational and packing analysis performed by molecular mechanics have given the lowest energy conformation of the polymer chain in the crystal state and the lowest ener…
Crystallization of polyethylene terephthalate and i-polypropylene in nonisothermal conditions is studied by means of differential scanning calorimetry. Measurements, carried out at several constant cooling rates, are interpreted in terms of a new theory1,2 that takes into account effects related to a transient, nonste…
Extended x-ray-absorption fine-structure has been utilized to measure the composition dependence of the Ge-Ge and Ge-Si bond lengths in both crystalline and amorphous ${\mathrm{Ge}}_{x}{\mathrm{Si}}_{1\ensuremath{-}x}$ alloys. Utilizing a new sample preparation technique, transmission measurements were performed over…
The hole effective-mass Hamiltonian for the semiconductors with wurtzite structure is given. The effective-mass parameters are determined by fitting the valence-band structure near the top with that calculated by the empirical pseudopotential method. The energies and corresponding wave functions are calculated with th…