检索结果-南通市图书馆

Analysis and design of CW-LD pumped stable Q-switched laser

在线全文

学校读者我要写书评

暂无评论

通信学报 2004年第12期25卷 171-175页

作者： HUANGXiu-jian SUIZhan LIMing-zhong LIUYong-zhi LIXin SchoolofOptic-electronicinformation Univ.ofElectronicScienceandTechnologyofChinaChengdu610054China／／LaserFusionResearchCenterofCAEEMianyang621000China LaserFusionResearchCenterofCAEEMianyang621000 China SchoolofOptic-electronicinformation Univ.ofElectronicScienceandTechnologyofChinaChengdu610054China SchoolofElectricalEngineering Univ.ofElectronicScienceandTechnologyofChinaChengdu610054China

A high power continuous wave (CW) laser diode (LD) pumped acousto-optic Q-switched Nd:YVO4 laser is presented. A short pulse at the 1064 nm is obtained. With a repetition rate of 50 kHz,the maximum average output power of 5.72 W is achieved. The optical conversion efficiency and the slope efficiency are up to 28% and 32.4% respectively. At the repetition rate of 10 kHz and the pulse width of 16.3ns, the maximum single pulse energy of 286 μJ and the peak power of 13kW are acquired. The laser can be used as a signal source in the free-space optical communication. The output signal agrees with the modulate signal well.

关键词：固体激光器 CW-LD 激光器二极管光量开关激光信号源声光Q开关

DETECTION ON MICRO-DOPPLER EFFECT BASED ON LASER COHERENT RADAR

在线全文

学校读者我要写书评

暂无评论

Journal of Electronics(China) 2012年第1期29卷 56-61页

作者： SunYang ZhangJun Factory704ofNavy Qingdao266109China InstituteofOpto—electronicinformation YantaiUniversityYantai264005China

A laser coherent detection system of 1550 nm wavelength was presented, and experimen- tal research on detecting micro-Doppler effect in a dynamic target was developed. In the study, the return signal in the time domain is decomposed into a set of components in different wavelet scales by multi-resolution wavelet analysis, and the components are associated with the vibrational motions in a target. Then micro-Doppler signatures are extracted by applying the reconstruction. During the course of the final data processing frequency analysis and time-frequency analysis are applied to analyze the vibrationM signals and estimate the motion parameters successfully. The experimental results indicate that the system can effectively detect micro-Doppler information in a moving target, and the tiny vibrational signatures also can be acquired effectively by wavelet multi-resolution analy- sis and time-frequency analysis.

关键词： Micro-Doppler effect Laser coherent radar Multi-resolution analysis Time-frequencyanalysis

Travelling Waves in a Compressible Mooney-Rivlin Rod

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Shanghai University(English Edition) 2001年第4期5卷 282-286页

作者： YUFeng LUOJing－guo 等 DeparmtentofMathematics CollegeofSciencesShanghaiUniversityShanghai200436China DepartmentofPhoto－electronicinformation＆ElectronicEngineering TianjinInstituteofTechnologyTianjin300

This article deals with waves in a circular cylindrical rod composed of a compressible Mooney Rivlin material. All kinds of travelling waves and the conditions for their existence are studied by using the method of ... 详细信息

关键词： travelling wave hemoclinic orbit heterclinic orbit

High pulse energy femtosecond large-mode-area photonic crystal fiber laser

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2008年第23期53卷 3741-3745页

作者： SONG YouJian HU MingLiet ZHANG Chi CHAI Lu WANG ChingYue Ultrafast Laser Laboratory College of Precision Instruments and Opto-electronics Engineering Key Laboratory of Opto-electronicInformation Science and Technology of Ministry of Education Tianjin University Tianjin 300072 China

A high pulse energy femtosecond fiber laser based on a large-mode-area photonic crystal fiber is demonstrated. A segment of Yb-doped single-polarization large-mode-area photonic crystal fiber with extremely low nonlinearity is explored as gain media of this fiber laser, resulting in intrinsically environmentally stability. The fiber laser is based on a linear cavity with dispersion compensation free configuration, and the stable mode-locking is obtained by a semiconductor saturable absorber mirror (SESAM). The fiber laser directly generates 2.5 W of average power at a repetition rate of 51.4 MHz, corresponding to a single pulse energy of 50 nJ. The output pulse duration is 4.2 ps, which is dechirped to 410 fs after extracavity dispersion compensation. The nonlinear absorption of SESAM determines the pulse shaping at low output power, while the mode-locking mechanism is under the balance between spectrum broadening from self-phase-modulation and gain filtering at the high output power.

关键词：光晶体纤维光纤激光器脉冲能耗大模式纤维

Microfluidic-based single cell trapping using a combination of stagnation point flow and physical barrier

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Sinica 2016年第3期32卷 422-429页

作者： Miao Yu Zongzheng Chen Cheng Xiang Bo Liu Handi Xie Kairong Qin Department of Biomedical Engineering Faculty of ElectronicInformation and Electrical Engineering Dalian University of Technology Dalian 116024 China Department of Electrical and Computer Engineering National University of Singapore Singapore 117576Singapore Western Reserve Academy Hudson OH 44236 USA

Single cell trapping in vitro by microfluidic device is an emerging approach for the study of the relationship between single cells and their dynamic biochemical microenvironments. In this paper, a hydrodynamic-based microfluidic device for single cell trapping is designed using a combination of stagnation point flow and physical *** microfluidic device overcomes the weakness of the traditional ones, which have been only based upon either stagnation point flows or physical barriers, and can conveniently load dynamic biochemical signals to the trapped cell. In addition, it can connect with a programmable syringe pump and a microscope to constitute an integrated experimental *** is experimentally verified that the microfluidic system can trap single cells in vitro even under flow disturbance and conveniently load biochemical signals to the trapped cell. The designed micro-device would provide a simple yet effective experimental platform for further study of the interactions between single cells and their microenvironments.

关键词： Single cell trapping Microfluidics Stagnation point flow Physical barrier Hydrodynamic tweezers Dynamic biochemical signal

Open-circuit voltage analysis of p-i-n type amorphous silicon solar cells deposited at low temperature

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2011年第8期20卷 403-407页

作者： Ni Jian Zhang Jian-Jun Cao Yu Wang Xian-Bao Li Chao Chen Xin-Liang Geng Xin-Hua Zhao Ying Institute of Photo-electronics Thin Film Devices and Technique of Nankai University Key Laboratory of Photo-electronics Thin Film Devices and Technique of Tianjin Key Laboratory of Photo-electronicInformation Science and Technology of Ministry of Education (Nankai University) Tianjin 300071 China

This paper identifies the contributions of p-a-SiC：H layers and i-a-Si：H layers to the open circuit voltage of p-i-n type a-Si：H solar cells deposited at a low temperature of 125℃. We find that poor quality p-a-SiC：H films under regular conditions lead to a restriction of open circuit voltage although the band gap of the i-layer varies widely. A significant improvement in open circuit voltage has been obtained by using high quality p-~SiC：H films optimized at the ＂low-power regime＂ under low silane flow rates and high hydrogen dilution conditions.

关键词： amorphous silicon solar cell low temperature open-circuit voltage

A novel algorithm of adaptive IIR lattice notch filter and performance analysis

在线全文

学校读者我要写书评

暂无评论

Journal of Shanghai University(English Edition) 2007年第5期11卷 485-489页

作者：秦鹏蔡萍 School of electronicinformation and Electrical Engineering Shanghai Jiaotong University Shanghai 200030 P. R. China

A novel adaptive algorithm of IIR lattice notch filter realized by all-pass filter is presented. The time-averaged estimation of cross correlation of the present instantaneous input signal and the past output signal is used to update the step-size, leading to a considerably improved convergence rate in a low SNR situation and reduced steady-state bias and MSE. The theoretical expression for steady-state bounds on the step-size is derived, and the influence factors on the stable performance of the algorithm theoretically are analyzed. A normalized power factor is then introduced to control variation of step-size in its steady-state bounds. This technique prevents divergence due to the influence of large power input signal and improves robustness. Numerical experiments are performed to demonstrate superiority of the proposed method.

关键词： lattice notch filter adaptive algorithm cross correction steady-state bounds normalized power factor.