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。
In this paper the quantum limit of heat transport induced by ultrashort laser pulses is discussed. The new quantum heat transport equation is derived. The relaxation time tau and diffusion coefficient D^e are calculated.
The optical absorption spectra of \ensuremath{\pi} electrons are calculated for graphite and carbon nanotubes. Particular attention is paid to the processes contributing to the optical absorption as a function of the electron wave vector k and light polarization direction. The optical absorption amplitude around the K…
Single-walled carbon nanotubes coated with crystalline tin oxide by a simple chemical-solution route are reported. The room-temperature chemical treatment results in a nominally complete and uniform coating over the entire outer surface of singular nanotubes, nanotube bundles, and also fullerene-like nanoparticles. Th…
Carbon nanotubes (CNTs), due to their unique electronic and extraordinary mechanical properties, have been receiving much attention for a wide variety of applications. Recently, plasma enhanced chemical vapour deposition (PECVD) has emerged as a key growth technique to produce vertically-aligned nanotubes. This paper…
The effects of pH on the formation and microstructure of barium titanate (BaTiO3) prepared by a coprecipitation process have been investigated. After calcination of the precipitates at 800°C, pure BaTiO3 was formed in samples prepared from oxalic solutions with pH in the range 5-7, and the powders obtained exhibited s…
The determination of bifurcation of equilibrium in micromachined elastic structures with liquid interface is posed as nonlinear boundary-value problems associated with spatially distributed models involving fluid forces. Explicit nonlinear algebraic equations for determining the bifurcation points associated with micr…
Abstract In situ photochromic process in the monolayer of a photochromic spiropyran derivative without long alkyl chain, was investigated. The photochromism at the air/water interface under different surface pressures was studied by surface pressure‐area isotherms, surface pressure‐time curves, area‐time curves and Br…
Abstract Differently prepared Si 3 N 4 based ceramics were examined from different aspects of the tribological behaviour: Mechanical and microstructural characteristics have been studied investigating the possible effect of a post heat‐treatment process on the wearing properties. Vacuum tribometer was used for measuri…
In this paper we report the results of calculations of the energies associated with the segregation of boron on the [Formula: see text] surface. These calculations have been carried out using the plane wave pseudopotential density functional code fhi98md in a periodic slab formalism. The segregation energy is predicte…
The surface chemical behavior of clean uranium metal in a hydrogen atmosphere at 80°C and 120°C has been studied using XPS and thermodynamic calculation. The main product is uranium oxide rather than hydride uranium on the uranium surface after the exposure of uranium to extremely pure hydrogen, and the U4f 7/2 bindin…
Abstract Models for the crystal structure of cis ‐1,4‐poly(2,3‐dimethyl‐1,3‐butadiene) are elucidated by the joint use of molecular mechanics and WAXS. The chain conformation can be predicted by using different sets of potential functions. A model of crystal structure calculated by molecular mechanics has been refined…
This paper reviews methods available for mapping the distribution of fluid in incontinence pad materials to assist with evaluating existing products and developing new ones, and to provide data for building and validating predictive models. Specifically, the following technologies are considered and their strengths an…
The effect of unidirectional propagation of surface electromagnetic waves on the interface between an isotropic Faraday medium and isotropic optically inactive medium is predicted. Such waves can be excited when the intensity of an external magnetic field exceeds a certain threshold. Solutions to the dispersion relati…
Abstract Positively charged tetra(4‐N,N,N,N‐ trimethylanilinium) porphyrin (TAP) and negatively charged tetrakis(4‐sulphonatophenyl) porphyrin (TPPS 4 ) and their mixtures with dopa melanin in polyvinyl alcohol have been investigated. On the basis of the absorption and fluorescence spectra it has been established the…
Abstract The main problem in post‐consumer plastics recycling is due to the thermomechanical stress acting on the melt during the reprocessing operations. The macromolecules break because of the temperature and of the mechanical stress. The extent of degradation is then correlated to the level of mechanical stress whi…
The QUENCH06 test at Forschungszentrum Karlsruhe (FZK) selected to be the international standard problem (ISP) No. 45 by OECD/NEA has been analyzed by the IMPACT/SAMPSON code, a detailed analysis code for severe accidents in an LWR. The code has been used to perform blind and open phase analyses of the quench phenomen…
Propriedades termofísicas, difusividade térmica e calor específico, de soluções modelo similares a sucos, foram determinadas experimentalmente e ajustadas a modelos matemáticos (STATISTICA 6.0), em função da sua composição química. Para definição das soluções modelo foi realizado um planejamento estrela mantendo-se fi…
T em per at ure dependen ces ( 4{ 300 K ) of t he electron spin-lattice rela xation ha ve b een determined by electron spin echo techni que for free radicals in tw o polymeric systems : phenol-formald ehyde resin and p olyhydra zodi sulphide . T he dep endences are describ ed in terms of dynamics specic for amorphous…
Typical magnetically functionalized Al2O3/Ni nanocomposite materials were fabricated by pulse electric current sintering process. The rapid densification and various microstructures were accomplished with controlling PECS temperature. The PECSed Al2O3/Ni system exhibited peculiar mechanical and magnetic properties wit…
Abstract Solid materials contain impurities from manufacturing/cleaning processes which diffuse (out‐gas) to the exterior during exposure to vacuum, especially at elevated temperature levels. Materials like plastics and resins tend to disintegrate under space conditions. In addition to the above mentioned diffusion pr…