Papers by Author: Ji Jun Xiong

Abstract: The quality of designing structure and properties of sensor photoionization room，directly determines its weak signal detection sensitivity detection and effecting ionization chamber detection efficiency .The paper experiments on four factors of affect the sensitivity of sensor. The results show that: the signal intensity proportional to the area of the ionization chamber; signal intensity goes up with the increase of bias voltage, and with bias voltage into a square the relationship; signal strength was first increased and then decreased with the growth of the distance between electrodes; signal strength was first increased and then decreased. With the growth of light-driven power.

Abstract: A novel MEMS vector hydrophone with bionics structure was introduced in 2007. As the acoustic-electric transducer infrastructure has been optimized, the performance of the hydrophone has been greatly improved compared with the previous. This hydrophone calibration was finished in National Defense Underwater Acoustics Calibration Laboratory of China. According to test results, the sensitivity of the hydrophone is -165dB（including pre-amplification 20 dB）,The frequency response ranges from 20Hz to 2kHz (±5dB). And this hydrophone has a good directional pattern in form of "8"-shape.

Abstract: Piezoelectric thin films cantilevers with a central Si mass are designed for harvesting vibration energy applications. Through the theoretic analyzer and MATLAB simulation, the displacement, resonance frequency and maximum stress dependent of the different structure parameters of micro-power device are obtained. It shows that increasing the quality of mass and the length of microcantilever, decreasing the width and thickness of microcantilever can realize the low-frequency resonance and maximum power in actual design. The static and mode analysis of the theory model are done by using Ansys 11.0. The results can provide guidance for the design and fabrication process of micro power generator.

Abstract: (Pb,La)(Zr,Ti)O₃ antiferroelectric thick films were prepared on Pt (111)/ Ti/SiO₂/Si (100) substrates by a sol-gel process. The effects of single annealing and multistep annealing on the structures and electric properties of the films were investigated. The crystal orientation and structure of the antiferroelectric thick films were studied. The thick films by multistep annealing have higher (100)-preferred orientation than them by single annealing. The surface of the films was more smooth, compact and uniform by single annealing. The antiferroelectric nature of the (Pb,La)(Zr,Ti)O₃ antiferroelectric thick films by various sintering procedures was demonstrated by P(polarization)-E(electric field) and C(capactitance)-E(electric field). The temperature dependent of the dielectric constant and loss was measured under the frequency 1, 10, and 100 kHz and comparing with traditional signal annealing, the films have phase transition from antiferroelectric state to paraelectric state by multistep annealing.