Advanced Materials Research Vols. 753-755

Abstract: For the problem of inefficient data access of the SQLite embedded database on S3C2440 (ARM9)-based hardware platform, this paper puts forward a design to transplant it to a more advanced S3C6410 (ARM11)-based platform. Through comparative experiments, this program is proved to be able to meet the needs of accessing mass data on the process of developing embedded program.

Abstract: With the rapid improvement of people's living standard,computer has become a necessity in daily life, followed by a huge amount of keyboard. The traditional wireless illuminant keyboard brings convenience to the life,however also consumes more energy and causes environmental pollution . Based on this situation, we plan to design a new type of energy-saving illuminant keyboard, on the one hand it can use the travel of keyboard to drive the generator; On the other hand it takes advantage of the magnetic flux changes when pressing to generate electricity. In addition, it can use extrusion of fingers on the keyboard to generate electricity by the plated PVDF film .Ultimately achieving the effect of energy saving and convenient.

Abstract: According to the International Electrotechnical Commission issued IEC61000-4-2 testing standards, through the electrostatic discharge current waveform characteristics analysis and numerical experiment method, using exponential pulse signal and the damped sinusoidal signal to construct a new the ESD current expression. Using Laplace transform, established the ESD system mathematical model. According to the mathematical model, construct double second-order circuit model of the ESD system, and the simulation is carried out. The simulation results meet the IEC61000-4-2 standard, and verify the consistency of the ESD current expression, the mathematical model and the circuit model.

Abstract: Reactive power problem of PV station in distribution power system is discussed. Probability theory is introduced to calculate the expectation of active power, which is approximately used to replace the randomly changing output. Reactive output can be adjusted by changing some related parameters of the grid-connected PV system. Considering reactive power of PV station as control variables, a model with voltage level constraints of minimizing the active power loss is established and its optimal solution is figured out with IBCC (Improved Bacterial Colony Chemotaxis). Case calculation results show the validity of above-mentioned model and algorithm.

Abstract: Magnetic antenna has many advantages such as small volume, high SNR and no grounding needed. Especially in some special environment such as water, the superiority is more obvious. According to its basic principle, this article discusses the structure characteristics, pivotal parameter and fundamental devising thinking. Its operational principle is simple. There will be a response current when the magnetic line of flux passes through the hoop. Its resonance oscillation frequency is decided by the inductance and the electric capacity in the circuit. The coiling way and circle are the critical factors to its receiving feature except the permeability, the length and the thickness of magnetic material. The design must be sure impedance matching in order to keep the signal out in the most power.

Abstract: In the power conversion, power supply in parallel to increase capacity and reliability is a commonly used method; and the current ripple have a great impact on the size and weight of the power supply. DC-DC parallel power supply ripple in the buck circuit model based on analysis, Fourier series expansion of the current continuous state of a single DC power inductor current, commence on the series and parallel power simulation study. Analysis and simulation results show that interleaved parallel can effectively inhibit the output current ripple.

Abstract: Based on the fact that there is a good amplitude correlation between neighbour bins of a communication signal, we presented a new blind source separation method applied to the wireless communication. Since there is no complicated mathematic derivation in this method, it is relatively simple in theory. Furthermore, wavelet de-noising processing is proposed finally. It yields good results in the experiment and improves the performance of BSS system applied to the wireless communication. In addition, this method is robust and time saving.

Abstract: With the development of factory automation technology, Profibus-DP fieldbus and Modbus protocol has become the most widely used communication technology at home and abroad, but the choices which can accomplish the data conversion between these two devices is not enough. According to the Modbus RTU communication agreement for the use of frequency converter, the article provides a kind of communication interface based on Profibus-DP and the Modbus communication protocol conversion which mainly introduces its hardware and software design scheme, and expounds the dependability and real-time performance of the communication interface.

Abstract: With the rapid development of the car, the importance of car alarm system has been confirmed. In recent years, the car alarm system has been continuously improve and development,make the whole system which is complex and difficult to see clearly to clear and intuitive anti-theft system test bench,and then do research and experiment teaching, this is a good way to study. This article makes the car alarm system into a test bench, using network interconnection, microcomputer control, serial port communication and TCP/IP, intuitive shows its composition and working principle, provides the basis for teaching and research. In the study, crack the anti-theft system control problems, achieve the remote control, provide a great convenience for teaching research and teaching, etc.

Abstract: In order to overcome deterioration of heat transfer caused by two-phase flow and avoid flow separation, using volume expanding evaporator instead of steam-water separator to make integration and optimization between parabolic trough solar energy collection system and coal-fired power plant regenerative heating system. Then based on equivalent enthalpy drop method, it analyses the thermal economy about 300MW coal-fired unit to discuss the optimal integration solutions and works out the unit thermal economy variation tendency and the best back water position of the drain in volume expanding evaporator when the different stage extraction steam of coal-fired unit replaced by the exit steam of solar collection system super heater region. The results show that the whole third stage extraction steam replaced by solar heat and drain water in volume expanding evaporator returned back to 3 heater exit of coal-fired unit feedwater pipeline is the best scheme.