Quantitative Detection of Superoxide Ions in Whole Blood of the American Alligator (Alligator mississippiensis)

WST-1 and nitroblue tetrazolium (NBT) were used to quantify production of superoxide ions by leukocytes of the American alligator in whole blood. Because of the difficulty of isolating healthy leukocytes in alligators, these compounds were employed in whole blood instead of leukocyte preparations commonly used in other studies. The detection of superoxide was concentration- and time-dependent and linear with serial dilutions of whole blood. WST-1 reduction was inhibited by superoxide dismutase, indicating that the reduction was due to the presence of superoxide. Light microscopy revealed that superoxide production occurred in leukocytes, with no detectable contributions from other blood components.     

AlNxOy thin films deposited by DC reactive magnetron sputtering

AlN_xO_y thin films were produced by DC reactive magnetron sputtering, using an atmosphere of argon and a reactive gas mixture of nitrogen and oxygen, for a wide range of partial pressures of reactive gas. During the deposition, the discharge current was kept constant and the discharge parameters were monitored. The deposition rate, chemical composition, morphology, structure and electrical resistivity of the coatings are strongly correlated with discharge parameters. Varying the reactive gas mixture partial pressure, the film properties change gradually from metallic-like films, for low reactive gas partial pressures, to stoichiometric amorphous Al₂O₃ insulator films, at high pressures. For intermediate reactive gas pressures, sub-stoichiometric AlN_xO_y films were obtained, with the electrical resistivity of the films increasing with the non-metallic/metallic ratio.     

Computational modelling of multi-material energetic materials and systems

ABSTRACT

In this paper, we present a systematic roadmap for developing a robust and parallel multi-material reactive hydrodynamic solver that integrates historically stable algorithms with new and current modern methods to solve explosive system design problems. The Ghost Fluid Method and Riemann solvers were used to enforce appropriate interface boundary conditions. Improved performance in terms of computational work and convergence properties was achieved by modifying a local node sorting strategy that decouples ghost nodes, allowing us to set material boundary conditions via an explicit procedure, removing the need to solve a coupled system of equations numerically. The locality and explicit nature of the node sorting concept allows for greater levels of parallelism and lower computational cost when populating ghost nodes. Non-linear numerical issues endemic to the use of real Equations of State in hydro-codes were resolved by using more thermodynamically consistent forms allowing us to accurately resolve large density gradients associated with high energy detonation problems at material interfaces. Pre-computed volume tables were implemented adding to the robustness of the solver base.     

Thickness effect on the band gap of magnetron sputtered Pb45Se45O10 thin films on Si

Oxygen doped PbSe thin films with different thickness were grown on the Si (100) substrates by magnetron sputtering, and characterized using scanning electron microscopy, energy dispersive X-ray spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy and physical properties measurement system. As the film thickness increased, the intensity of the (200) PbSe prominent diffraction peak increased, while the (220) peak almost vanished, indicating the primary growth direction. The change rate between the light and dark resistance increased with the film thickness, and the maximum of 64.76% was obtained. According to the density functional theory calculations and the experimental results, the band gap of the PbSe thin films decreased from 0.278 eV to 0.21 eV when doped with oxygen. Doping with oxygen during the deposition process is a viable way to prepare PbSe thin films with a tunable band gap. The band gap increased almost linearly with the lattice constant, confirmed by the calculated and experimental results.     

Thin-film multi-layer capacitors using Bi2Mg2/3Nb4/3O7 (BMNO) pyrochlore thin films via radio-frequency sputtering

Thin-film multi-layer ceramic capacitors (MLCCs) were prepared using high-dielectric constant Bi₂Mg_2/3Nb_4/3O₇ thin-films deposited at room temperature via radio-frequency magnetron sputtering. The multi-layer capacitors, in sizes 0402, 0603 and 1005, were well equipped with both inner and outer Cu electrodes. The capacitances of the bi-layer capacitors were twice that of the single-layer version in sizes 0402, 0603, and 1005. The 200 nm-thick Bi₂Mg_2/3Nb_4/3O₇ thin-films would be suitable for thin-film multi-layer capacitor applications.     

Crystallization and electrical properties of V2O5 thin films prepared by RF sputtering

V₂O₅ thin films were prepared under various conditions by using reactive RF sputtering technique. The microstructure and electrical properties of the films are have been investigated. X-ray diffraction data revealed the films deposited at low O₂/Ar ratio are amorphous. The orthorhombic structure of film improved after post annealing at 873 K. The microstructure parameters (crystallite/domain size and macrostrain) have been evaluated by using a single order Voigt profile method. Using the two-point probe technique, the dark conductivity as a function of the condition parameters such as film thickness, oxygen content and temperature are discussed. It was also found that, the behaviour of ρd versus d was found to fit properly with the Fuchs-Sondheimer relation with the parameters: ρ_o = 2.14 × 10⁷ Ω cm and ?_o = 112 ± 2 nm. At high temperature, the electrical conductivity is dominated by grain boundaries, the values of activation energy and potential barrier height were 0.90 ± 0.02 eV and 0.92 ± 0.02 V, respectively.     

射频辉光放电CH4等离子体一维流体动力学模拟

完整建立一个关于射频辉光放电CH₄等离子体的流体动力学模型.模型包括基于迁移-扩散近似的粒子平衡方程、电子能量平衡方程,共包含了20种粒子(环境气体粒子,激发态粒子,离子和电子)和49类化学反应(电子-中性环境粒子、离子-中性环境粒子、激发态粒子-激发态粒子(中性环境粒子)).结果表明,在强电场区域有较高的电子反应率系数;等离子体中除源气体CH₄外,H₂,C₂H₆,C₃H₈,C₂H₄和C₂H₂也有较高的密度含量;激发态粒子中,CH₃含量最高,密度约为10¹⁹m^-3;在较低放电压力时(如18 Pa),CH₅⁺在离子成分中密度含量最高,当放电压力较高时(如67Pa),C₂H₅⁺在离子成分中占主导地位;除C₂H₅⁺外,其它各离子和激发态粒子在极板上的粒子流量随功率的增大逐渐升高.     

The ferroelectric and ferromagnetic characterization of CoFe2O4/Pb(Mg1/3Nb2/3)O3-PbTiO3 multilayered thin films

The multiferroic (PMN-PT/CFO)_n (n = 1,2) multilayered thin films have been prepared on SiO₂/Si(1 0 0) substrate with LNO as buffer layer via a rf magnetron sputtering method. The structure and surface morphology of multilayered thin films were determined by X-ray diffraction (XRD) and atom force microscopy (AFM), respectively. The smooth, dense and crack-free surface shows the excellent crystal quality with root-mean-square (RMS) roughness only 2.9 nm, and average grain size of CFO thin films on the surface is about 44 nm. The influence of the thin films thickness size, periodicity n and crystallite orientation on their properties including ferroelectric, ferromagnetic properties in the (PMN-PT/CFO)_n multilayered thin films were investigated. For multilayered thin films with n = 1 and n = 2, the remanent polarization Pr are 17.9 μC/cm² and 9.9 μC/cm²; the coercivity H_c are 1044 Oe and 660 Oe, respectively. In addition, the relative mechanism are also discussed.     

Structural and optical properties of RF magnetron sputtered aluminum nitride films without external substrate heating

We report structural and optical properties of aluminum nitride (AlN) thin films prepared by RF magnetron sputtering. A ceramic AlN target was used to sputter deposit AlN films without external substrate heating in Ar-N₂ (1:1) ambient. The X-ray diffraction and high resolution transmission electron microscopy results revealed that the films were preferentially oriented along c-axis. Cross-sectional imaging revealed columnar growth perpendicular to the substrate. The secondary ion mass spectroscopy analysis confirmed that aluminum and nitrogen distribution was uniform within the thickness of the film. The optical band gap of 5.3 eV was evaluated by UV-vis spectroscopy. Photo-luminescence broad band was observed in the range of 420-600 nm with two maxima, centered at 433 nm and 466 nm wavelengths related to the energy states originated during the film growth. A structural property correlation has been carried out to explore the possible application of such important well oriented nano-structured two-dimensional semiconducting objects.     

Effect of C60 ion sputtering on the compositional depth profiling in XPS for Li(Ni,Co,Mn)O2 electrodes

The performance of a Li-ion cell strongly depends on the solid-electrolyte interface (SEI) on electrodes. The depth distribution of composition in SEI is normally determined by means of X-ray Photoelectron Spectroscopy (XPS) via Ar ion sputtering. Recently, a new kind of ion gun using C60 ions as sputtering source was introduced. In this report, a comparison between the effects of these two kinds of ion guns on the quantification of Li(Ni,Co,Mn)O₂ electrodes was made. It was found that the C60 ion gun is more suitable for analyzing the composition and chemical state of Li(Ni,Co,Mn)O₂ electrode since that it causes lower chemical damage in the superficial layer.