Applied Mechanics and Materials Vols. 336-338

Abstract: The ward calling system of a special radio frequency wireless transceiver chip transmission has been designed . This system avoids the trouble of wiring and reconstruction for traditional wired paging system. Combining the single address coding technology, SCM is used as controller, and the latest call bed number is storage automatically and is displayed circularity. Historical number is deleted by the delete key. This system enhances connection of the nursing station and the ward and improves the level of care. The system has a great practical value in the medical service system reform.

Abstract: In order to study the relation of temperature and focal plane and confirm the focal plane based on temperature and guarantee the imaging quality for space camera, the calibration system of temperature and focal plane was proposed. Firstly, the condition on temperature balance was analyzed. Secondly, the evaluation method of image was introduced. Thirdly, the system structure and operating principle were introduced. Finally, the system was designed. Experimental results indicate that the position of focal plane is decided by the average temperature of primary mirror when the temperature of space camera is in balance. The calibration error is no more than 0.051μm and satisfies the requirement of system design.

Abstract: For high energy short pulse discharge applications, like electromagnetic launchers or magnetic forming, mostly the thyristor technology is used. The presented thyristor switch assemblies using 125 mm wafer size are made to switch 62.4MJ stored energy into a load in very short time. The maximum transient peak current of 26 kilo-amperes peak for 20 ms with convection water and air cooling. For this presentation we concentrate on the Thyristor technology as this offer the highest current capability but are not in the position to switch-off any current. Some measures must be used to the pulse switch centered on Thyristor device, i.e., proper selection of the static and dynamic parameters of the thyristor, enough power for triggering the device, and efficient cooling of the device, which can make it possible to produce devices with high blocking voltage combined with very high current handling.

Abstract: In the performance testing for diesel engine, the load of power testing mostly used water resistance. The power generated by diesel engine all consumed by water resistance. The power and water wasted mostly by this way. Base on the existing mechanical energy recovery system means that the system adopt generator dragged by prime motor to generate recycle electricity, this paper introduces variable current energy recovery system. The power voltage inverts to 10kV voltage, and connects the power plants to the grid. Research shows that the system is low cost, energy saving. And it is achieved the ideal effect in power quality and economic benefit. At present, our company cooperates with a locomotive works for design and construction this system and ancillary plant.

Abstract: This paper has designed a secure electric vehicle charging pile control device according to such security problems as the traditional electric vehicle charging pile control devices transmission data can be illegally intercepted easily in electrical communication process. The electric vehicle charging pile control device has used advanced data encryption technology, increased secure storage unit, which can prevent transmission data being intercepted or falsified illegally in electrical communication process effectively, so as to ensure datas integrity and confidentiality. Therefore, it has great practical value.

Abstract: This paper presents the development of the PCBs functional tester and the application of matrix relay in this system. It is stressed on the structure of relay matrix switch and its basic control mode. A topology of cascaded relay switch network is also proposed. The relay matrix in switch networks can achieve flexible connections of I/O pins on the specific PCBs being tested with varies signal resources and output processing modules without any hardware changes in the different test flows, only by PLC program changes. Therefore, complex test wiring can be saved when interface varied, as well as the enhancement of systematic universality. .

Abstract: A new method for splitting drops on a piezoelectric substrate is presented. An interdigital transducer with the period of 144μm is fabricated on a 128° yx-LiNbO₃ piezoelectric substrate using microelectric technology. Intermittent surface acoustic wave is generated by an on-to-off radio frequency signal, which is applied to the interdigital transducer, and then radiates into a drop on the acoustic path of the piezoelectric substrate, leading to discontinuous acoustic streaming. A part of the drop is split due to inertia when the surface acoustic wave is suddenly disappeared. Red dye solution drops are demonstrated for fission experiments, and mixture operation of two drops is also implemented using the fission method. Results show that a drop can be split by help of surface acoustic wave, and the distance of two daughters is determined on the volume of the drop. The presented drop fission method provides a new sample preparation technique, which is helpful for microfluidic biochemical analysis in a microfluidic system.

Abstract: The analysis of the acoustic field distribution characteristics for the ultrasonic transducer array plays a very important role in both the optimization of the design parameters of the array and the improvement of image quality. In this paper, the acoustic analysis method based on spatial impulse response is studied for the linear MEMS ultrasonic transducer array. The spatial impulse response for the ultrasonic transducer array and the lateral ultrasonic radiation field for the transducer array are obtained by simulation and calculation, and the simulation results are analyzed, which has important implications on the further optimization of MEMS ultrasound transducer design parameters.

Abstract: The major technical difficulty of time domain reflectometry (TDR) based cable fault location lies in the accurate measurement of the time of flight (TOF). The measurement of such time intervals is realized by a digital counter together with a reference clock. Theoretical analysis is established to prove that the resolution can be refined to nanosecond by averaging the counting results from a massive number of repetitive measurements. A microcontroller is used to generate a repetitive step signal in order to perform the repetitive test. 8 MHz clock and 8-bit digital counter are used to measure the time of flight. Experimental results showed that the timing resolution of the counter method is improved to nanosecond using the mean of 30,000 times of measurement results. A portable prototype for cable fault location is made to verify such a configuration. Test results showed that the position of the cable fault can be located with error of less than 0.1m.

Abstract: Under high voltage and ferromagnetic condition, the optical fiber, as the new communication carrier, is widely used in power signal transmission. However, the interference rejection performance of optical-fiber transceiver, an important part of photoelectric conversion, has always been of great concerns. Whether the optical fiber transceiver works properly or not, will directly affect the quality of the whole communication network. This paper focuses on the time-domain and frequency-domain features of power ports and control ports under the strong transient electromagnetic disturbance. At the same time, this paper makes use of magnetic toroid to suppress electromagnetic interference (EMI). The results provide a reference for future anti-jamming design of optical-fiber transceivers.