Nanospherical titanium oxide with anatase structure was obtained at low temperature and normal pressure using a simple method of preparation. The dilute titanium (III) chloride solution was stirred at room temperature for several hours, and then ammonium hydroxide with hydrogen peroxide was added. A yellow gel TiO2·xH2O was obtained with nanodot shape and amorphous structure. Heated at 300 °C, it crystallized to pure anatase structure with nanospherical shape. The anatase particles prepared show good adsorption and photodegradation of Congo red solution under the sunlight. Materials were characterized by powder X-ray diffraction, thermal analysis, transmission electron microscope and UV spectroscopy. 相似文献
A Monte Carlo model considering the electron spin direction and spin asymmetry has been developed. The energy distribution of the secondary electron polarization and the primary energy dependence of the polarization from Fe are studied. The simulation results show that: (1) the intensity of the spin-up secondary electrons is larger thanvthat of thevspin-down secondary electrons, suggesting the secondary electrons are spin polarized; (2) the spin polarization of secondary electrons with nearly zero kinetic energy is higher than the average valance spin polarization, Pb=27% for Fe. With increasing kinetic energy, the spin polarization of the secondary electrons decreases to the value of Pu remaining constant at higher kinetic energies; (3) the spin polarization increases with an increase in the primary energy and reaches a saturation value at higher primary energy in both the Monte Carlo simulation and experimental results. 相似文献
The full energy distribution of backscattered electrons from the elastic peak down to the true-secondaty electron peak for heavy metals, Ta, W, Pt and Au, in Auger electron spectroscopy in the EN(E) mode has been studied with a Monte Carlo simulation method, which includes cascade-secondary-electron production. The simulation model is based on the use of a dielectric function for describing inelastic scattering and secondary excitation, and on the use of Mott cross sections for elastic scattering. A systematic comparison between the calculated and experimental spectra measured with a cylindrical mirror analyzer has been made for primary energies ranging from 1 to 5keV. Excellent agreement was obtained for these heavy metals on the backscattering background at primary energies in the keV region. A significant contribution of cascade secondary electrons to the measured spectra on the low-energy side was found. 相似文献
This paper studies the thermal behavior of a wireless powered micropump operated using thermo-pneumatic actuation. Numerical analysis was performed to investigate the temporal conduction of the planar inductor-capacitor (LC) wireless heater and the heating chamber. The result shows that the temperature at the heating chamber reaches steady state temperature of 46.7°C within 40 seconds. The finding was further verified with experimental works through the fabrication of the planar LC heater (RF sensitive actuator) and micropump device using MEMS fabrication technique. The fabricated device delivers a minimum volume of 0.096 μL at the temperature of 29°C after being thermally activated for 10 s. The volume dispensed from the micropump device can precisely controlled by an increase of the electrical heating power within the cut-off input power of 0.22 W. Beyond the power, the heat transfer to the heating chamber exhibits non-linear behavior. In addition, wireless operation of the fabricated device shows successful release of color dye when the micropump is immersed in DI-water containing dish and excited by tuning the RF power.
Grade 92 steel (9Cr-2W) is a ferritic-martensitic steel with good mechanical and thermal properties. It is being considered for structural applications in Generation IV reactors. Still, the irradiation performance of this alloy needs more investigation as a result of the limited available data. The irradiation performance investigation of Grade 92 steel would contribute to the understanding of engineering aspects including feasibility of application, economy, and maintenance. In this study, Grade 92 steel was irradiated by iron ion beam to 10, 50, and 100 dpa at 30 and 500 °C. In general, the samples exhibited good radiation damage resistance at these testing parameters. The radiation-induced hardening was higher at 30 °C with higher dislocation density; however, the dislocation density was less pronounced at higher temperature. Moreover, the irradiated samples at 30 °C had defect clusters and their density increased at higher doses. On the other hand, dislocation loops were found in the irradiated sample at 50 dpa and 500 °C. Further, the irradiated samples did not show any bubble or void. 相似文献
Iranian Polymer Journal - Hydrogels were produced from mixtures of polyvinyl alcohol (PVA), polyvinyl pyrrolidone (PVP), and acrylic acid (AAc) using γ-radiation at doses of 3, 7, and... 相似文献