Xiao Lv

An Approach for Detecting Illegal Load in Wireless Power Transfer System

In wireless power transfer (WPT) system, detection of illegal load especially the metallic illegal load is necessary to protect the system safety due to the high frequency electromagnetic. This paper presents an efficient and easily-realized method based on energy channels for detecting the legitimacy of load in WPT system. The method is designed that the load at a given frequency to carry out on-off modulation and the primary part demodulation to judge the legitimacy of the load according to the energy equilibrium equations. To realize the proposed method, the relation between primary DC(direct current) input current and secondary load resistance have been analyzed. Therefore, the final detection method is set up which is only required sampling the frequency of DC input current to avoid complex system modeling and requirements of high speed sampling system. Finally experiment and simulation have verified the method which is much efficient and easily-realized for detecting the legitimacy of load accurately.

Research of Mining High Power 802.11n Access Point

This paper designs and implements an IEEE 802.11n based mining high power access point to improve the disadvantages of low throughput, low communication distance which are met in current mining communication systems. By adding high power design to transmitting and receiving path, this design can get over more than 190Mbps throughput in lab testing, and can achieve more than 2km outdoor communication distance. Test results show that the mining high power access point is more suitable for mining application.

An IEEE 802.11n Based Multi-Channel MAC Protocol for Underground Metal Mine Wireless Network

At present, wireless communication networks obtain preliminary application in underground metal mines, but the problems of anti-interference ability and communication capability generally exist. With regard to this situation, this paper proposed an IEEE 802.11n based multi-channel MAC protocol (MC-MAC), which supports multi-channel dynamically switching by evaluating real time channel packet received rate. MC-MAC can improve wireless networks’ data throughput, anti-interference ability, and communication reliability. To evaluate the practical performance of MC-MAC, This paper designed and implemented an wireless access point based on IEEE 802.11n as testing platform, experimental results show that MC-MAC can provide 193Mbps physical links rate and improve network anti-interference ability effectively, it is suitable for underground metal mine applications.

Preparation and characterization of CdTe/Porous silicon system

We report the structural and photoluminescence properties of CdTe/Porous silicon (PS) composite system prepared by chemical vapor deposition. The XRD pattern accord with the standard pattern of cadmium telluride of the samples was evaluated and the morphology of CdTe particles was characterized by scanning electron microscopy. The composite sample gives a strong luminescence and the mechanism of photoluminescence with CdTe/PS has also been discussed.

Preparation and Characterization of ZnS/ZnO Compound Grown on Porous Silicon Substrate Using CVD Method

We have investigated the morphology and photoluminescence (PL) of Zinc Oxide (ZnO) and Zinc sulphide (ZnS) compound grown on porous silicon at room temperature. Under different excitation wavelengths (320 nm, 340nm, 370 nm), the photoluminescence (PL) spectra of PS-ZnS-ZnO composites were different, and at 550nm there is a strong photoluminescence peak. Energy dispersive spectroscopy (EDS) has been carried out to evaluate the existing of ZnO/ZnS compound. In addition, the scanning electron microscopy (SEM) observation shows that the morphology of the PS-ZnS-ZnO composites was well grown on porous silicon.

Porous Silicon Immunosensor for Label-Free Detection of SpaA

A novel immunosensor based on porous silicon (PSi) for antigen detection was reported in this paper. The antigen (SpaA) and the specificity of the antibodies are employed as the target and the probe in our laboratory, respectively. The immunosensor structure was prepared using bioconjungation. After the antigen-antibody reaction, the red shift of the reflection spectrum of the immunosensor increases in proportion to the concentration of SpaA. The sensitivity of this immunosensor is 41nm/ µg•ml-1 and the detection limit is 2.44×102pg•ml-1, they are better compared with our previous work by using this method. Controlled experiments were also presented with non-immune antibody and the results show that this immunosensor possesses high specificity.

Improved Photoluminescence from Ar+ and N+ Ions Co-Implanted Porous Silicon

We have measured photoluminescence of porous silicon which is electrochemically prepared on single crystal silicon wafer with co-implantation of Ar+ and N+ ions. The results show that the photoluminescence intensity of porous structure of co-implanted silicon was enhanced that we attribute these to the enhanced formation of porous silicon microstructure induced by ion implantation and from the analysis by scanning electron microscopy, it is demonstrated that the different density of the pores with different doses ion implantation