Applied Mechanics and Materials Vols. 130-134

Abstract: Base on three dimension (3D) finite element method (FEM), a electromagnetic model for a power distribution transformer is established. The core loss, stray losses in structural components are simulated, the effects of magnetic shunts on tank losses are studied, then compared with experiments. The core loss, the decrease of stray losses when using magnetic shunts are in accordance with experiments. Studies indicate that tank loss is the most impartment part of stray losses in this model, magnetic shunts are effective in reducing stray losses.

Abstract: This paper reports a novel kind of solid micro-gyroscope, which is called piezoelectric micromachined modal gyroscope (PMMG). PMMG has large stiffness and robust resistance to shake and strike because there is no evident mass-spring component in its structure. This work focused on quantitative optimization of the gyroscope, which is still blank for such gyroscope. A set of quantitative indicators were developed to optimize the operation mode and corresponding device size was obtained. By FEM, the harmonic analysis was conducted to find the way to efficiently actuate the operation mode needed. At last, the Coriolis analysis was conducted to show the relation between angular velocity and differential output voltage by the Coriolis force under working condition.

Abstract: A novel Plasma generator is manufactured by Micro-hollow cathode discharge, and it will be used in industry as the contaminated gas disinfection devices. The power supply of the plasma generator is manufactured by high-frequency convertor technology with series-resonant power stage and parallel-load output. In order to improve the reliability of power supply, the mutual-lock circuit of two-switch device is designed. The effective modulation circuit is given in order to realize the many operation-modes of the plasma generator. The experimental results indicate that the power supply operates in resonant condition and realizes the zero current and zero voltage switching. The modulation circuit can adjust the operation-modes of the plasma generator, satisfying the demand of the plasma generator operation.

Abstract: Small scale high-voltage flyback charging circuit is the key unit of the initiating experiment device of slapper detonator, which converts the initiating energy from low voltage to high voltage and stores the energy in a high voltage capacitor. It is a highly nonlinear system, of which the research topic is the process of the establishment of the output voltage—an area which belongs to large signal transients. This has made the research of this topic difficult and progress slowly. In this paper, in order to study the characteristics as well as the rules of the charging process for the purpose of design optimization, the discrete time domain model of the flyback charging circuit is built and simulated. Experimental results are given and show that the model presented in this paper is instrumental for the optimization of the high voltage charging circuit.

Abstract: . Silicon carbide (SiC) SITs were fabricated using home-grown epi structures. The gate is a recessed gate - bottom contact (RG - B). We designed that the mesa space 2.7μm and the gate channel is 1.2μm. One cell has 400 source fingers and each source finger width is 100μm. 1mm SiC SIT yielded a current density of 123mA/mm of drain current at a drain voltage of 20V. A maximum current density of 150 mA/mm was achieved with Vd=40V. The device blocking voltage with a gate bias of-16 V was 200 V. Packaged 24-cm devices were evaluated using amplifier circuits designed for class AB operations. A total power output in excess of 213 W was obtained with a power density of 8.5 W/cm and gain of 8.5 dB at 500 MHz under pulse operation.

Abstract: In order to solve dynamic schedule problem brought by disturbance in steelmaking, the disturbance and corresponding method are classified. Man-machine cooperated method are brought out. Gantt chart is used to help man-machine cooperating, algorithm of conflict adjusting is used to ensure validity of dynamic schedule. Based all the work above, Man-machine schedule system is built in the end.

Abstract: We fabricated and analyzed the 10Gb/s EML TOSA packaged module. An optimized CPW feed line was employed for the module, and greatly improved the performance of the module compared to the module with the conventional CPW. With this optimized CPW feed line, a clear back to back (BTB) eye opening of optical output waveform with mask margin of 20% and extinction ratio was 10.45dB.

Abstract: We investigate behaviors of vehicles passing a controlled area with variable speed limits (VSL) before a tollgate. The traffic flow mathematical model is formulated based on optimal velocity model. The typical sketch of tollgate area is plotted and variable speed limit signs are set in the area to control the traffic flow speed for fear of accident and congestion. Simulations are carried out to examine the influence on traffic flow passing the controlled area with different number of the speed limit signs under open boundary condition. The simulations results show that more speed limit signs may reduce the risk of rear-end collision and the occurrence of the congestion in the tollgate area.

Abstract: This paper discusses the implementation of a new travel time estimation method in a regional demand forecasting model. The developed model considers implicitly the influence of signal timing as a function of main street and cross street traffic demands, although signal timing setting is not required as input. The application presented in this paper demonstrates that the developed model is applicable to a large network without the burden of signal timing input requirement. The results indicate that the application of the model can improve the performance of traffic assignment as part of the demand forecasting process. The model is promising to support dynamic traffic assignment (DTA) model applications in the future.

Abstract: Lots of information including vary raw materials components and mechanical properties should be involved in the electrode design process. It was very difficult to manage them. In this article, an effective solution by simulating the artificial design process of electrode was presented in the design of intelligent electrode design system (IEDS). That successfully realized series functions such as electrode formula management, electrode intelligent design. Shared file, named pipe, and file mapping were proposed to solve the communication problem between design module and prediction module which were developed by using different languages and platforms.