ARXPS-analysis and morphology of sputtered nanocrystalline TiC/SiC coatings

ARXPS (angle resolved X-ray photoelectron spectroscopy) measurements are used to obtain informations about surfaces and grain boundaries. Data acquired from nanocrystalline carbidic hard coatings have been employed to establish structural models. Magnetron-sputtered coatings of TiC, SiC and TiC/SiC were examined. In such coatings, partly defective TiC nanocrystallites are surrounded by interfacial carbide. This excess carbon shows a binding state similar to that of doped graphite or fullerenes. X-ray amorphous SiC is found in the residue. On top of sputtered SiC coatings, less oxide and graphite is found as compared to TiC/SiC or TiC coatings.     

(NH4)2MoS4在活性炭上浸渍过程的研究:Ⅱ.干燥机理及模型

（ＮＨ＿４）＿２ＭｏＳ＿４在活性炭上浸渍过程的研究Ⅱ．干燥机理及模型秦慧芳，张成芳，陆岗，俞丰，朱子彬（华东理工大学无机化工研究所，上海２００２３７）２３７）关键词硫代钼酸铵，活性炭，干燥，钼分布，干燥模型负载型催化剂的活性组分在载体上的分布，受浸渍...     

Spin-relaxation and magnetoresistance in FM/SC/FM tunnel junctions

The effect of spin relaxation on tunnel magnetoresistance (TMR) in a ferromagnet/superconductor/ferromagnet (FM/SC/FM) double tunnel junction is theoretically studied. The spin accumulation in SC is determined by balancing of the spin-injection rate and the spin-relaxation rate. In the superconducting state, the spin-relaxation time τ_s becomes longer with decreasing temperature, resulting in a rapid increase of TMR. The TMR of FM/SC/FM junctions provides a useful probe to extract information about spin-relaxation in superconductors.     

Multivalued differential equations on closed convex sets in Banach spaces

New derivation results for integrands and multifunctions via the Lipschitzean approximations are obtained. Applications to multivalued differential equations on closed convex sets are presented.     

Spectral pattern recognition of improved voice quality

The self-organizing map (a neural network) was applied to the spectral pattern recognition of voice quality in 34 subjects: 15 patients operated on because of insufficient glottal closure and 19 subjects not treated for voice disorders. The voice samples, segments of sustained /a/, were perceptually rated by six experts. A self-organized acoustic feature map was first computed from tokens of /a/ and then used for the analysis of the samples. The locations of the samples on the map were determined and the distances from a normal reference were compared with the perceptual ratings. The map locations corresponded to the degree of audible disorder: the samples judged as normal were overlapping or close to the normal reference, whereas the samples judged as dysphonie were located further away from it. The comparison of pre- and postoperative samples of the patients showed that the perceived improvement of voice quality was also detected by the map.     

Temperature dependence of magnetization in nanocrystalline FeCoZr alloy

The temperature dependence of magnetization of a nanocrystalline Fe₆₀Co₃₀Zr₁₀ alloy annealed at various temperatures to varying crystal sizes was investigated down to 5 K in the field range up to 5 T. The fitting procedure gave T^3/2 as the leading term irrespective of the crystal size. We suggest that the increase of the coefficient by this term for smaller crystals may be connected to an increased relative volume of their surface.     

Measurements and simulations of particle dispersion in a turbulent flow

A particle imaging technique has been used to collect droplet displacement statistics in a round turbulent jet of air. Droplets are injected on the jet axis, and a laser sheet and position-sensitive photomultiplier tube are used to track their radial displacement and time-of-flight. Dispersion statistics can be computed which are Lagrangian or Eulerian in nature. The experiments have been simulated numerically using a second-order closure scheme for the jet and a stochastic simulation for the particle trajectories. Results are presented for non-vaporizing droplets of sizes from 35 to 160 μm. The simulations have underscored the importance of initial conditions and early droplet displacement history on the droplet trajectory for droplets with large inertia relative to the turbulence. Estimates of initial conditions have been made and their effect on dispersion is quantified.     

SpecTool: a knowledge-based hypermedia system for interpreting molecular spectra

Summary A hypermedia environment was designed to set up a collection of reference data, reference spectra and computational tools. The system may serve as an aid for the combined interpretation of molecular spectra. This paper describes the context dependent presentation of the pieces of information.     

Electrochemical reduction of Bi2Sr2Ca1Cu2O8 superconductor single crystals

Single crystals and polycrystalline pellets of the high-temperature cuprate superconductor Bi₂Sr₂Ca₁Cu₂O₈ were doped at room temperature by electrochemical reduction at > 95% Coulombic efficiency using lithium dopant ions in propylene carbonate electrolyte. Cyclic voltammetry and potential step measurements on single crystals suggest an unusual reduction mechanism, with a diffusion coefficient for Li⁺ in the c-axis direction of bulk superconductor of ca. 3 × 10⁻¹¹ cm²s⁻¹. Sintered pellets of polycrystalline powder could be doped more rapidly, with an apparent diffusion coefficient of 7 × 10⁻⁸ cm²s⁻¹. X-ray susceptibility analysis show extensive disordering occurs on heavy Li doping, with a first-order transition from a crystalline/superconducting to an amorphous/non-superconducting phase. Single, crystals of Bi₂Sr₂Ca₁Cu₂O₈ exhibited a color change on reduction from metallic gray to golden bronze. The reduced material was highly air-sensitive, forming a hydroxide surface film on exposure to ambient atmosphere.