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Chinese Academy of Sciences Institutional Repositories Grid
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The investigation of point defect modes of phononic crystal for high Q resonance (EI CONFERENCE) 会议论文  OAI收割
2011 16th International Solid-State Sensors, Actuators and Microsystems Conference, TRANSDUCERS'11, June 5, 2011 - June 9, 2011, Beijing, China
作者:  
Liu J.;  Liu J.;  Liu J.;  Li F.
收藏  |  浏览/下载:21/0  |  提交时间:2013/03/25
Evaluation of the operating range for ground-based infrared imaging tracking system (EI CONFERENCE) 会议论文  OAI收割
International Symposium on Photoelectronic Detection and Imaging 2011: Advances in Infrared Imaging and Applications, May 24, 2011 - May 24, 2011, Beijing, China
作者:  
Zhang Z.-D.
收藏  |  浏览/下载:49/0  |  提交时间:2013/03/25
Ground-based infrared imaging tracking system (GIITS) is of great importance for aerial target warning and guard. The operating range is one of the key performance specifications  on the other  which should be calculated  calculate the radiation power received on the detector in order to analysis whether the output signal meets the detection requirements or not  analyzed and studied during the whole GIITS design process. The operating range is mostly influenced by a few factors  without considering the effect of the background radiation. By improving of the traditional method  including atmospheric attenuation  a new operating range calculation model of the GIITS was established based on two requirements. One is that the image size of observed target should meet the requirement of the processor signal extraction. The number of the pixel occupied by target image should be more than 9. The other is that the signal noise ratio (SNR) of the GIITS should not be less than 5 to meet the requirements of the target detection probability and spatial frequency. The SNR calculation equation in form of energy is deduced and the radiation characteristic of the observed target and background are analyzed. When evaluate the operating range of the GIITS using the new method  the performance of GIITS and feature of target and background. This paper firstly makes analysis and summarization on the definite localizations of the traditional operating range equation of the GIITS. The localizations are mainly in two aspects. On one hand  we should successively calculate two operating range values according to two requirements mentioned above and choose the minimum value as the analytic result. In the end  the dispersion of the image and the effect of image dispersion are not considered in the traditional method  an evaluation of operating range for fighter aircraft is accomplished as an example. The influence factors in every aspect on operating range were explored by the calculated result. The new operating range calculation model provides the theoretical basis for the design and applications as well as the comprehensive evaluation of a GIITS. 2011 Copyright Society of Photo-Optical Instrumentation Engineers (SPIE).  
Attenuation of lateral propagating light in sea ice measured with an artificial lamp in winter Arctic 期刊论文  OAI收割
COLD REGIONS SCIENCE AND TECHNOLOGY, 2010, 卷号: 61, 期号: 1, 页码: 6-12
作者:  
Zhao, J. -P.;  Li, T.;  Barber, D.;  Ren, J-P;  Pucko, M.
收藏  |  浏览/下载:32/0  |  提交时间:2015/07/20
Far-field focusing of laser beam based on digital image processing techniques (EI CONFERENCE) 会议论文  OAI收割
Optoelectronic Imaging and Multimedia Technology, October 18, 2010 - October 20, 2010, Beijing, China
作者:  
Zhao S.;  Tian Y.-Z.;  Liu L.-S.;  Guo J.;  Zhang H.-Y.
收藏  |  浏览/下载:28/0  |  提交时间:2013/03/25
In order to lead the laser beam transmit in the atmosphere convergently  an experiment of laser focus at the distance of 450m and 300m has been operated in the outdoor place. The actual manipulations are as follows: Firstly  the laser was collimated by a beam expander  then the near-parallel laser beam was transmitted with a Galileo telescope system  and the distance between the concave lens and the convex lens can be tuned through a precise displacement platform  so the focus of the system changed due to the tiny displacement of the concave lens. Secondly  the average power of the laser spot can be measured using power meter  the power is 47.67mW and the standard deviation is 0.67mW while the focal length is 450m. Thirdly  the energy distribution was found through the laser beam analyzer. The spot images were saved using the beam analyzer  then the saved image can be processed with Matlab software afterwards. The function named EDGE and Sobel operator was used in the pre-processing of the saved image  then method of median filter was used in the course of image de-noising and 53H filter was adopted in the signal analysis. The diameter of laser spot was obtained by the method above  the diameter is 5.56mm and the standard deviation is 0.24mm. The spot center excursion is 0.56mm  it is 10.43% of the total diameter of the laser spot. At last  the key factors of the energy dissipation in the focusing system can be summarized as follows: restriction of the diffraction limit  attenuation in the atmosphere  geometrical aberration of optical system  and the diffraction limit and the geometrical aberration are significant in the three factors above  so we can reduce the impact of the both factors during the design of optical system. The reliable referenced data of the system design can be acquired through the primary experiment research. 2010 SPIE.  
Linearity measurement for image-intensified CCD (EI CONFERENCE) 会议论文  OAI收割
5th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Optical Test and Measurement Technology and Equipment, April 26, 2010 - April 29, 2010, Dalian, China
作者:  
Zhang L.;  Zhao Y.;  Zhao Y.;  Zhao Y.;  Yan F.
收藏  |  浏览/下载:34/0  |  提交时间:2013/03/25
To the characteristic of the ultraviolet CCD (UV ICCD)  technique of the linearity measurement of the UV ICCD camera is studied based on the theory of radiometry. Approach of linearity measurement is discussed  and a kind of measurement system of the UV ICCD has been developed based on the method of neutral density filter. It is very important that the transmittance of the filter is independent of the wavelength in the method of neutral density filter. Black metal screen mesh with different transmittance is used in our system  and calibration of the filters' transmittance in different working positions has been done. Meanwhile  to assure the uniform of the received radiation on the target of the detector at any test points  an integrating sphere is placed behind the neutral filter to balance light. The whole measurement system mainly consists of a deuterium lamp with high stabilization  the attenuation film with transmission  integrating sphere  optical guide and electro-shift platform. Auto control is realized via special software during the test. With this instrument  the linearity of the UV ICCD was measured. Experimental results show that the nonlinearity of the UV ICCD under fixed-gain is less than 2% and the uncertainty of measurement system is less than 4%. 2010 Copyright SPIE - The International Society for Optical Engineering.  
Electrically-controlled near-infrared chiroptical switching of enantiomeric dinuclear ruthenium complexes 期刊论文  OAI收割
chemical communications, 2009, 期号: 12, 页码: 1529-1531
Li D; Wang ZY; Ma DG
收藏  |  浏览/下载:267/76  |  提交时间:2010/05/27
Variation in downwelling diffuse attenuation coefficient in the northern South China Sea 期刊论文  OAI收割
CHINESE JOURNAL OF OCEANOLOGY AND LIMNOLOGY, 2008, 卷号: 26, 期号: 3, 页码: 323-333
Wang, GF; Cao, WX; Yang, DT; Xu, DZ
收藏  |  浏览/下载:23/0  |  提交时间:2011/07/03
基于傅里叶变换的光纤探头光谱特性校正方法的研究 期刊论文  OAI收割
光谱学与光谱分析, 2005, 卷号: 25, 期号: 4, 页码: 541, 543
孟宪江; 张铁强; 施伟杰; 申铉国
收藏  |  浏览/下载:1229/223  |  提交时间:2009/09/18
Towards the improvement of attenuation range and response time of electrochromic polymer-based variable optical attenuators 期刊论文  OAI收割
OPTICAL MATERIALS, 2004, 卷号: 27, 期号: 2, 页码: 265-268
作者:  
Zhang, JD;  Yu, HA;  Wu, MG;  Wang, ZY
  |  收藏  |  浏览/下载:14/0  |  提交时间:2019/04/09