Abstract: A sandwich device structure of MIM (metal/insulator/metal) is designed and its metal-insulator transition induced by an external electric field is investigated. VOx films were deposited on several different substrates by dc magnetic sputtering at room temperature. The device of Pt/VOx/Cu/Ti/SiO2/Si exhibited steady bipolar resistance switching behaviors between high resistive state (HRS) and low resistive state (LRS) with-0.4V/0.3V operation voltage (SET/RESET), while the devices of Pt/VOx/V/Cu/Ti/SiO2/Si, Pt/VOx/Al/Ti/SiO2/Si and Pt/VOx/Pt/Ti/SiO2/Si didn’t show this steady characteristic. From the comparison of these devices based on different substrates, the Schottky Emission model was quoted to explain this resistance switching characteristic in Pt/VOx/Cu/Ti/SiO2/Si device.
Abstract: In this paper a PLC control system is designed to control the sorting, transmission and loading/unloading in the manufacturing, in view of the defects of the relay control system which usually has poor reliability and bad flexibility in use. On the basis of the superior performance of PLC control system and the working principle of frequency converter, AC transducer drive technology is applied to achieve stable starting, reliable operation and low breakdown rate in the assembly line of manufacturing. In the design of the upper monitoring system, the functions of parameter settings, process monitoring and control, data processing, fault location can be well implemented via configuration software. The research work of this paper will lay a solid foundation for the design of material automatic sorting system based on the PLC controller.
Abstract: To measure the elasticity specificity of equivalent bio-materials with human skin's nature, the static-load pressing method for testing the elastic nature of the equivalent material for human skin is approached in this paper. And it is very important and useful to biomedicine science and engineering that evaluating correctly the mechanical property of the equivalent materials with human skin's nature.
Abstract: Ultrafine e grain amorphous silicon nitride (Si3N4) powders were produced via direct nitridation process of silicon powders in transport bed. The properties of the nitridation products, such as morphology, phase composition, chemical composition and structure, were examined using standard characterization techniques (SEM, XRD, FTIR, etc). The experimental results showed, in the case of silicon powders with particle size of 2.7μm, the conversion rate of silicon was 53.4% at reaction temperature of 1380°C and reaction time of 2.7minutes, and the products mainly comprised amorphous silicon nitride powders.
Abstract: The insulation material epoxy resin mean molecular weight to its solidification electrical performance influence is discussed. In view of the bisphenol A epoxy resin with different mean molecular weights, Finite Element Method (FEM) are introduced and electric field calculation equations are established to calculate the field distribution of basin insulator and its around region in GIS. Representative potential distribution curves are shown. The tangential and normal electric filed intensity maximum of basin insulator is calculated. The positions of electric field intensity maximum are also given.
Abstract: The Al2O3 films doped with Ce3 + were deposited on slides by the medium-frequency reaction magnetron sputtering process, to which the power is constant, Ar flow rate 70 sccm, O2 flow rate 25~45sccm and sputtering time 90min at room temperature. The relationship between the luminescent properties of Al2O3:Ce3 + films and the doped amount of Ce3 + in the films was studied. The presence of Ce3 + and stoichiometry of those films were determined. It was observed that the total luminescence intensity increases and the peak positions are strongly dependent on Ce3+ concentration in the films. The analysis of luminescent excitation spectra showed that the luminance is due to the Ce3+ concentration in the cerium chloride aggregate formed in the films.
Abstract: The plate butt welding tests have been carried out to the 2219 high-strength aluminum alloy material by utilizing the self-development compound high frequency pulse TIG power source, whose results show that the mechanical properties of the welding seam may be effectively enhanced by adding the high frequency pulse energy. Therefore, a acoustic emission sensing system was established to acquire the transmission effect of the high frequency pulse arc energy during the welding process; moreover, the influence on the welding seam microstructures by the compound high frequency pulse energy has been studied. The results show the following effects: the porosity number at the both sides of the welding seam fusion line may be decreased significantly by adding the high frequency pulse energy; The analysis to the high frequency pulse action mechanism has been carried out according to the above conclusions to provide the technology theory base for improving and enhancing the aluminum alloy welding joint performances.
Abstract: Usually there is a sliding between the contact surfaces of the connector, while the changes in temperature and humidity environment would affect the resistance of the connector contact materials. This paper studies the complicated effects of environment and sliding on the dynamic resistance of the contacts materials of Pd-Ni plated. Series of inspections and analytical research methods are introduced in this article. The surface morphology of specimens after damp heat cyclic test is observed by stereoscopic microscope and scanning electron microscope (SEM). Chemical constitution was examined by X-ray energy spectrum. The contact resistances were measured under the conditions of damp heat cycle by four-point method. The results show that the temperature and humidity environment and sliding has a more complex and significant impact on the performance of the contact materials than single-factors, and the tests are closer to the real working environment.
Abstract: An Improved High-Accuracy CORDIC (COordinate Rotation Digital Computer) algorithm for digital scan conversion is presented in this paper to enhance the accuracy and speed of coordinate conversion for Endoscopic Ultrasonography. Several optimization methods are carried out to make coordinate conversion implemented more exactly with fewer resources of FPGA. In the paper, the Cartesian coordinates are re-demarcated to save LE (Logic Element) resources of FPGA. The bit width of data, the scale factor correction and the convergence range are all optimized to improve the accuracy of the algorithm. Further more, a special processing for the near-field data is carried out to reduce the errors of digital scan conversion. With a full pipeline structure implemented on FPGA, the Improved High-Accuracy CORDIC algorithm is validated by both simulation and real-time ultrasound imaging experiment, making the accuracy enhanced and the image quality improved.