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Zhai Z.-X.,Key Laboratory of Instrumentation Science & Dynamic Measurement | Zhang P.-Z.,Key Laboratory of Instrumentation Science & Dynamic Measurement
Hedianzixue Yu Tance Jishu/Nuclear Electronics and Detection Technology | Year: 2015

This paper presents a design of small multi-channel data acquisition recording system with FPGA-carrier SOPC system as the master core. Acquisition module expands channel to 128 by time division multiplexing technology. Storage module is NAND FLASH memory chip. Data is stored by DMA technology for NAND FLASH pipelining so that the storage at maximum speed. Test results show that the number of acquisition channel can be changed flexibly from 1 to 128 and acquisition frequency can also have a variety of choices. © 2015, Editorial Board of Nuclear Electronics & Detection Tech. All right reserved. Source


Chen Y.,State Key Laboratory for Electronic Measurenent Technology | Wang Z.,State Key Laboratory for Electronic Measurenent Technology | Wang Z.,Key Laboratory of Instrumentation Science & Dynamic Measurement | Li W.,Tianjin Jinhang Institute of Technical Physics
Hongwai yu Jiguang Gongcheng/Infrared and Laser Engineering | Year: 2016

The infrared spectrum of mixed gas got in the battlefield and complex environment results in overlapping and stagger of the primary and secondary peaks, so its feature extraction of qualitative recognition is particularly important. The infrared spectral data collected from a variety of chemical warfare agents and organic gases are high-dimensional data. Centralizing before reducing dimension was used for feature extraction to capture the essence of more information it contained. Since the infrared spectrum of the mixed gas was non-linear and non-Gaussian signal, this method regarded non-Gaussian as independence measure to separate each component as independent component. In order to meet real-time requirements, its iterative process was optimized based on the traditional fast independent component analysis (FastICA) algorithm and extreme learning machine (ELM) model was applied to quantitative analysis. Experiment results show that the iterations of optimized method reduces compared with the traditional method and mean square error of quantitative analysis is E=2.3926×10-4 and regression coefficient is R=0.999. And the optimized method improves the isolated efficiency of separating pure substances spectra from mixture substances without affecting the separate accuracy. © 2016, Editorial Board of Journal of Infrared and Laser Engineering. All right reserved. Source


Jin S.,Key Laboratory of Instrumentation Science & Dynamic Measurement | Jin H.,Key Laboratory of Instrumentation Science & Dynamic Measurement | Jin H.,Soochow University of China | Zhang Y.,Key Laboratory of Instrumentation Science & Dynamic Measurement | Chen C.,Key Laboratory of Instrumentation Science & Dynamic Measurement
Hanjie Xuebao/Transactions of the China Welding Institution | Year: 2015

The size of solder joints connecting the chip and PCB in electronic products is smaller and smaller. Solder joint is the part which most easily is to damaged in the process of mechanical vibration shock. In order to study the problem of anti-high g value impact of chip SMT solder joint, the test of anti-high g value impact of two flash chips SMT solder joint has been carried out by using Hopkinson bar laser interferometer. The flash chip is the core storage chip in dynamic parameter testing. Results show that the flash chip SMT solder joint can resist the impact of the 1.3×105 g acceleration under the condition of no repeated impact and the ability to resist shock acceleration amplitude of SMT solder joint decreases rapidly in the cumulative impact cases. ©, 2015, Harbin Research Institute of Welding. All right reserved. Source


Zhang R.,State Key Laboratory for Electronic Measurement Technology | Zhang R.,Key Laboratory of Instrumentation Science & Dynamic Measurement | Wang Z.-B.,State Key Laboratory for Electronic Measurement Technology | Wang Z.-B.,Key Laboratory of Instrumentation Science & Dynamic Measurement | And 6 more authors.
Guang Pu Xue Yu Guang Pu Fen Xi/Spectroscopy and Spectral Analysis | Year: 2015

Existing Photoelastic Modulator (PEM), whose optical path difference (OPD) is small, has strict requirements on the incident spot size and is poor in the aspect of light use efficiency under multiple reflections. What's more, Photoelastic Modulator based Fourier transform spectrometer (PEM-FTS) spectral resolution is relatively poor. Because there are these disadvantages in the PEM, this paper presents a method of large optical path difference whose PEM is based on micro trapezoidal photoelastic crystals. By improving the structure of photoelastic crystal, the PEM becomes micro trapezoidal octagonal structure. And two transmission surfaces are changed slightly into a certain angle. Therefore, the PEM improved can not only increase the optical path difference of the PEM, but also have less requirements on the incident spot size. Firstly, a detailed analysis of the maximum modulation optical path difference was made in this paper. Secondly, the equation of maximum optical path difference was deduced under any angle and any position of incident light, vibration displacement and stress distribution of PEM are analyzed by the way of COMSOL Multiphysics 4.3a. Again, a method was analyzed to find the best angle of incidence, combining with maximum optical path difference and energy efficiency. Then the large OPD's PEM is designed and processed, including two parts: photoelastic crystal and piezoelectric crystal. Moreover, ZnSe crystal is used as photoelastic crystal, and piezoelectric quartz crystal is used as piezoelectric crystal. With experiment analyzed by 632.8 nm He-Ne laser, the results show that under the same driving voltage, the optical path difference of the PEM improved is about 19.25 times bigger than the normal PEM, and the relative error is 1.3%. ©, 2015, Science Press. All right reserved. Source


Zhang R.,State Key Laboratory for Electronic Measurement Technology | Zhang R.,Key Laboratory of Instrumentation Science & Dynamic Measurement | Zhang R.,North University of China | Wang Z.,State Key Laboratory for Electronic Measurement Technology | And 8 more authors.
Hongwai yu Jiguang Gongcheng/Infrared and Laser Engineering | Year: 2015

Existing static wedge interferometer can not achieve zero optical path difference, thereby affecting the accuracy and speed of spectral inversion. Therefore, a method of achieving zero optical path difference by improving the wedge structure was put forward. By improving the structure of the inclined surface, the wedge can be achieved on the incident light interference signal which contains zero optical path difference. By deducing and analyzing the optical path difference of the arbitrary wedge position, and the formula of spectral inversion was deduced. Using Zinc Selenide (ZnSe) materials design and processing of the wedge, interference signal and the optical path difference was simulated, and the process of spectral inversion was simulated. The wedge was analyzed by experiments which used 10.64 μm laser. Result shows that the interference signal clarity, optical path difference can reach 1450 μm, and the relative error of experiment is 0.1%. ©, 2015, Chinese Society of Astronautics. All right reserved. Source

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