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An experimental study on "flower" wave induced by thermocapillary convection and single point surface deformation features for thin fluid layers in open annular pool 会议论文  OAI收割
Beijing, China, September 23, 2013 - September 27, 2013
作者:  Zhang L(张丽);  Duan L(段俐);  Kang Q(康琦)
  |  收藏  |  浏览/下载：22/0  |  提交时间：2018/11/08
The effect of backlash nonlinear on resonance frequency of electric actuator transmission system (EI CONFERENCE) 会议论文  OAI收割
3rd IEEE International Conference on Advanced Computer Control, ICACC 2011, January 18, 2011 - January 20, 2011, Harbin, China
Han X.; Ge M.; Bai Y.; Jia H.; Ge W.
收藏  |  浏览/下载：23/0  |  提交时间：2013/03/25
In order to study the effect of backlash nonlinear on resonance frequency of electric actuator transmission system  then  Finally  in the premise of meeting the stability  the dynamic equilibrium equation of transmission system with backlash is established  it makes dynamic simulation analysis for the transmission system based on virtual prototype technology  it establishes balanced equation of dynamics system with backlash  the effect of backlash on system natural frequency and resonance frequency  and the theoretical values and simulation values are compared. Theoretical analysis and simulation results show that the theoretical analysis is basically consistent with simulation results when it is zero backlash  and does some theory research and dynamic analysis of backlash nonlinearity and system natural frequency and resonance frequency. First  and the error of theoretical analysis and simulation results is within 10%. Therefore  according to describing function to theoretically model the backlash nonlinear  it can be concluded that considering the transmission system theoretical analysis of backlash nonlinearity is feasible  the relation between describing function and the amount of backlash and input amplitude is analyzed  and it is much closer to the actual system with instructive significance. 2011 IEEE.  
Dynamic coupling analysis and modeling for stabilized platform of rolling-pitching seeker (EI CONFERENCE) 会议论文  OAI收割
2011 International Conference on Electric Information and Control Engineering, ICEICE 2011, April 15, 2011 - April 17, 2011, Wuhan, China
作者:  Liu H.;  Liu H.;  Liu H.
收藏  |  浏览/下载：12/0  |  提交时间：2013/03/25
Missile's attitude change will be delivered to visual axis through stabilized platform during maneuvering flight  and the missile vibration will be an interference source to visual axis stabilization. In order to solve this problem  the coupling relationship between missile attitude and visual axis is obtained by Coordinate transformation. When the seeker stably tracks a target  the angular velocity of visual axis in inertial space is zero  so the relative angular velocity of roll axis and pitch axis can be derived for servo control. According to Oura dynamics equation  the dynamic models of roll axis and pitch axis were established and kinetic equations of two axises were obtained. The dynamic models can provide theoretical basis to developing research of servo control system and structural optimization design of stabilized platform. Finally  some measures could reduce the dynamic coupling between the framework was given. 2011 IEEE.  
The research and implementation of the method of the Photoelectric theodolite simulation (EI CONFERENCE) 会议论文  OAI收割
2010 3rd International Conference on Advanced Computer Theory and Engineering, ICACTE 2010, August 20, 2010 - August 22, 2010, Chengdu, China
作者:  Li Y.;  Lu M.;  Li Y.;  Li Y.;  Li Y.
收藏  |  浏览/下载：16/0  |  提交时间：2013/03/25
Experiments of second harmonic generation output in pulsed TEA CO 2 laser (EI CONFERENCE) 会议论文  OAI收割
High-Power Lasers and Applications V, October 18, 2010 - October 19, 2010, Beijing, China
作者:  Li D.
收藏  |  浏览/下载：54/0  |  提交时间：2013/03/25
It is always the hot subject to realize the output of high-power laser in the range of 3-5m wavelength. This rang of wave band has greatly important applications in military because it located in the atmosphere window. Generally there are two ways to obtain this range of laser wavelength. One way is through optical parameter oscillation (OPO) from shorter laser wavelength and the other is through second harmonic generation (SHG) from longer laser wavelength. Firstly  the comparison between tow nonlinear crystals ZnGeP2 and AgGaSe2 is conducted for their nonlinear coefficient and damaging threshold in theory. The theoretical results show that the crystal AgGaSe 2 is more suitable for the SHG of pulsed TEA CO2 laser. When using pulsed TEA CO2 laser with wavelength of 9.3m to pumping AgGaSe2 SHG crystal  the wavelength of 4.65m is obtained. In the condition of repetition rate 100Hz  the upmost output power of single pulse is up to level of 1W  which corresponding efficiency of SHG is about 6%. The experimental results show that the polarization of laser beam has greatly influence on the SHG output of the crystal. Under the radiation of 3MW/cm 2 from fundamental wave and the right position for maximal SHG output in the crystal  when polarization of laser beam rotates 4.5  the SHG output of energy decrease about 30%. The research of this paper will make a foundation for further development of mid-infrared laser. 2010 Copyright SPIE - The International Society for Optical Engineering.  
R&D of comprehensive evaluation system of ecological environment in Tarim River basin 会议论文  OAI收割
2010 International Conference on Management and Service Science, MASS, Wuhan, China, 2010
Bao; An-Ming1; 2; Liu; Hai-Long3; Chen; Yun-Hao1; Xi2
收藏  |  浏览/下载：23/0  |  提交时间：2011/08/23
Analysis of laser jamming to satellite-based detector (EI CONFERENCE) 会议论文  OAI收割
International Symposium on Photoelectronic Detection and Imaging 2009: Laser Sensing and Imaging, June 17, 2009 - June 19, 2009, Beijing, China
作者:  Guo L.-H.;  Guo R.-H.;  Wang S.-W.
收藏  |  浏览/下载：29/0  |  提交时间：2013/03/25
The reconnaissance satellite  communication satellite and navigation satellite used in the military applications have played more and more important role in the advanced technique wars and already become the significant support and aid system for military actions. With the development of all kinds of satellites  anti-satellite laser weapons emerge as the times require. The experiments and analyses of laser disturbing CCD (charge coupled detector) in near ground have been studied by many research groups  but their results are not suitable to the case that using laser disturbs the satellite-based detector. Because the distance between the satellite-based detector and the ground is very large  it is difficult to damage it directly. However the optical receive system of satellite detector has large optical gain  so laser disturbing satellite detector is possible. In order to determine its feasibility  the theoretical analyses and experimental study are carried out in the paper. Firstly  the influence factors of laser disturbing satellite detector are analyzed in detail  which including laser power density on the surface of the detector after long distance transmission  and laser power density threshold for disturbing etc. These factors are not only induced by the satellite orbit  but dependence on the following parameters: laser average power in the ground  laser beam quality  tracing and aiming precision and atmospheric transmission. A calculation model is developed by considering all factors which then the power density entering into the detector can be calculated. Secondly  the laser disturbing experiment is performed by using LD (laser diode) with the wavelength 808 nm disturbing CCD 5 kilometer away  which the disturbing threshold value is obtained as 3.5510-4mW/cm2 that coincides with other researcher's results. Finally  using the theoretical model  the energy density of laser on the photosensitive surface of MSTI-3 satellite detector is estimated as about 100mW/cm2  which is largely exceed the disturbing threshold and therefore verify the feasibility of using this kind of laser disturbing the satellite-based detector. According to the results. using the similar laser power density absolutely saturate the requirements to laser disturbing satellite-based detector. If considering the peak power of pulsed laser  even decrease laser average power  it is also possible to damage the detector. This result will provide the reliable evidences to evaluate the effect of laser disturbing satellite-based detector. 2009 SPIE.  
Heterogeneous architecture-based software reliability estimation: Case study (EI CONFERENCE) 会议论文  OAI收割
3rd International Conference on Convergence and Hybrid Information Technology, ICCIT 2008, November 11, 2008 - November 13, 2008, Busan, Korea, Republic of
Wei Y.; Shen X.-H.
收藏  |  浏览/下载：28/0  |  提交时间：2013/03/25
With growing system complication  multiple structures are constructed in software  instead of single architecture style. As a result  the traditional architecture-based models that have considered only homogeneous software behaviors are not suitable to the complex system. In this paper a heterogeneous architecture-based model is presented. In order to verify the practicability  we apply the model to estimate the system reliability of the astronautics payload communication and monitoring system (APCMS). Multiple structures are constructed in the system  i.e.  sequence  parallel and fault-tolerance. The study results demonstrate that the model is accurate when compared to the actual reliability. Theoretical research must be applied on actual systems to understand their applicability and accuracy. 2008 IEEE.  
Research on the support structure of the primary mirror of large-aperture telescope (EI CONFERENCE) 会议论文  OAI收割
3rd International Symposium on Advanced Optical Manufacturing and Testing Technologies, AOMATT 2007: Large Mirrors and Telescopes, July 8, 2007 - July 12, 2007, Chengdu, China
Yang W.; Jingxu Z.
收藏  |  浏览/下载：27/0  |  提交时间：2013/03/25
Large-aperture telescope can be used in surveying battlefield  researching landform  searching object  real-time monitoring  imaging  detecting and identifying spatial targets and so on. A large-aperture telescope for achieving high resolution power is designed to monitor spatial target and image in real time. Real-time monitoring plays an important role in military conflicts. The orbit parameter of object  quantity  geometrical shape parameter and so on can be obtained by detect spatial target. With the development of optical technology  people require larger aperture in optics-electronic (OE) system. By increasing optical aperture  the ability of collecting light and resolution power in the system can be enhanced. But the support structure of the primary mirror of large-aperture telescope will be a very difficult problem. With the increase of primary mirror aperture  the weight of the primary mirror will become larger than before. The root mean square (rms) of the primary mirror is affected by many factors  such as deadweight  deformation of heat  environment and so on. Due to the primary mirror of telescope is an important component of telescope system. By reducing the weight of primary mirror  precision of the system is ensured. During the designing phase  one can consider the supporting project of the primary mirror synthetically and analyze it roundly according to technical requirement of optical system and the effect factors. The final structural design can be reasonable. In an astronomical telescope  the surface of reflector is an important part for collecting dark radiation of celestial bodies. Its surface shape will have an effect on collecting efficiency of telescope radiant energy directly. So the rms must be very high. Optical system of large aperture  small wavelength and small focus can receive maximal light intensity. For ground-based optical astronomical telescope  the design proposed in the paper can satisfy the requirement of the possible minimum atmosphere seeing at astronomical observatory site and exert the use efficiency of the telescope adequately. So the accuracy of the traditional surface of reflector can assure that 90% of all the light energy can be focused on within the angle diameter range of the minimum atmosphere seeing  then 100% of light energy should be focused on the angle diameter range of minimum atmosphere seeing. Because the rms of mirror is very high  precise surface machining and accurate the support of mirror are very important tasks during designing and manufacturing the telescope. In the paper  various support techniques of a large-aperture telescope primary mirror are discussed and a 3.5 meter telescope system at the Starfire Optical Range (SOR) overviewed simply  which was operated by the Directed Energy Directorate of the Air Force Research Laboratory  Kirtland AFB  NM  USA from the ground-based O-E system for the observations of spatial target. We also analyze Theoretical elastic deformation of the Steward Observatory 2.3 meter mirror is analyzed.  
Optical fiber transmission of Q-switdied Nd:YAG pulses of 10MW peak power: Mechanism of damage to the fiber (EI CONFERENCE) 会议论文  OAI收割
2nd International Symposium on Advanced Optical Manufacturing and Testing Technologies - Advanced Optical Manufacturing and Testing Technologies, November 2, 2005 - November 5, 2005, Xian, China
作者:  Wang L.;  Zhang Y.;  Chen W.;  Tang Y.;  Wang L.
收藏  |  浏览/下载：30/0  |  提交时间：2013/03/25
This paper presents theoretical analysis and experiment results of four different fibers transmitting 10MW peak power Nd: YAG laser pulse. The main factors limiting to optical fiber transmission of high power laser pulse is pointed  including air breakdown at focus area and surface damage of optical fiber. The theory of air breakdown and the fiber coupling conditions is described briefly. The results of study to the transmission properties and damage conditions are presented on the basis of four different types of optical fibers. The results of the experiments are further analyzed in the aspects of transmitting efficiency  air breakdown and surface damage. The local and foreign optical fibers  with plastic-cladding and silica-cladding  and step- index and graded- index fibers are tested separately in the experiments. The experiments showed that the imported fibers are able to transmit up to 10MW peak power laser pulse with no any visible damage  while energy density at the fiber output end surface is 3.54GW/cm2. For local fibers  damage on the input surface of both plastic-cladding and silica-cladding  step-index fibers was found obviously. The column damage to the graded index fiber was also found and investigated in the research. Damage mechanisms of fiber at high peak power laser pulses are summarized. High quality finishing of fiber end surface will improve damage threshold tremendously. The conclusion of the study is that transmitting Q-switched Nd:YAG pulses of 10MW peak power is feasible for the domestically made fibers if their end surfaces are properly processed.