消息
×
loading..
中国科学院机构知识库网格
Chinese Academy of Sciences Institutional Repositories Grid
机构
采集方式
内容类型
发表日期
学科主题
筛选

浏览/检索结果: 共8条,第1-8条 帮助

条数/页: 排序方式:
Structural design of large aperture rectangular mirror for space telescope (EI CONFERENCE) 会议论文  OAI收割
2nd International Conference on Civil Engineering and Transportation, ICCET 2012, October 27, 2012 - October 28, 2012, Guilin, China
作者:  
Li Z.;  Li Z.
收藏  |  浏览/下载:45/0  |  提交时间:2013/03/25
Structural design of large aperture mirror is one of the key technologies for space telescope development. To meet the requirements of high stiffness  strength and thermal dimensional stability  some factors such as support scheme  materials selection  lightweight design and flexible support design were taken into account. The three supports location of the mirror was determined according to the modal analytical solution. By adjusting the parameters of flexure hinge  influences of gravity  assembly stress and thermal stress on the mirror were reduced obviously. Finite element analysis (FEA) results indicate that the surface accuracy reach to rms10.2nm and 10.8nm under the gravity along optical axis direction and 5C uniform temperature rise respectively  the fundamental frequency of the mirror component is 268Hz. Dynamics test shows that the first order natural frequency is 256Hz  which shows an error less than 5% compared to FEA results. (2013) Trans Tech Publications  Switzerland.  
Comparison and simulation of subpixel imaging modes for linear CCD (EI CONFERENCE) 会议论文  OAI收割
2012 3rd International Conference on Information Technology for Manufacturing Systems, ITMS 2012, September 8, 2012 - September 9, 2012, Qingdao, China
作者:  
Li Y.;  He B.;  Li Y.;  Li Y.;  Li Y.
收藏  |  浏览/下载:40/0  |  提交时间:2013/03/25
Subpixel technique of linear CCD is effective to enhance the spatial resolution without increasing the focal length of optics and reducing the pixel size. To compare image quality of two main subpixel imaging modes  quincunx sampling and four-point sampling  a method to quantitatively evaluate image quality of subpixel based on MTF was proposed. The MTF of quincunx and four-point sampling modes were derived. Analytical results shows that theoretical limiting resolution of quincunx sampling and four-point sampling is improved to 1.4 and 1.86 times respectively  and MTF values at Nyquist frequency of two modes are increased by 0.1106 and 0.1679  respectively. MTFA in (0  0.5) of two subpixel imaging modes were calculated and results illustrates that four-point sampling offers much more improvement with image quality than quincunx sampling  at the cost of double amount of data. A model for simulating subpixel imaging using Matlab was established  and simulation results of spoke target verify the theoretical analysis. (2012) Trans Tech Publications  Switzerland.  
A fuzzy control method based on information integration for double inverted pendulum (EI CONFERENCE) 会议论文  OAI收割
2011 2nd International Conference on Digital Manufacturing and Automation, ICDMA 2011, August 5, 2011 - August 7, 2011, Zhangjiajie, Hunan, China
作者:  
Fan Y.
收藏  |  浏览/下载:66/0  |  提交时间:2013/03/25
This article proposes a new fuzzy controller based on information integration. The mathematical model of Linear double inverted pendulum has been studied and estabLished with dynamics analytical method and LQR theory is used to design the optimal Linear inverted pendulum controller  then  the integration technology is used to design the variable parameters self-tuning fuzzy controller. Thereby  the fuzzy controller input variable dimension and the number of fuzzy control rules have been extremely reduced. Two controllers are designed for inverted pendulum system control and the comparison simulation experiments have been done. The results show that the controllers can both reaLize good control  and the fuzzy controller has higher precision  faster response  better stabiLity and robustness. 2011 IEEE.  
A study of the axisymmetric thermal strain in a laser rod with longitudinal temperature rise 期刊论文  OAI收割
APPLIED THERMAL ENGINEERING, 2009, 卷号: 29, 期号: 14-15, 页码: 2927-2934
作者:  
Li, Zhigang;  Huai, Xiulan;  Wang, Li
收藏  |  浏览/下载:21/0  |  提交时间:2015/12/18
Modeling diffractive optical elements in hybrid systems with the effect of the material dispersion (EI CONFERENCE) 会议论文  OAI收割
Current Developments in Lens Design and Optical Engineering IX, August 11, 2008 - August 12, 2008, San Diego, CA, United states
作者:  
Zhang H.;  Liu H.;  Liu H.;  Liu H.;  Zhang H.
收藏  |  浏览/下载:16/0  |  提交时间:2013/03/25
The study on the near infrared spectrum technology of sauce component analysis (EI CONFERENCE) 会议论文  OAI收割
ICO20: Optical Information Processing, August 21, 2005 - August 26, 2005, Changchun, China
作者:  
Li S.;  Wang C.;  Chen X.;  Chen X.;  Chen X.
收藏  |  浏览/下载:37/0  |  提交时间:2013/03/25
The author  Shangyu Li  engages in supervising and inspecting the quality of products. In soy sauce manufacturing  quality control of intermediate and final products by many components such as total nitrogen  saltless soluble solids  nitrogen of amino acids and total acid is demanded. Wet chemistry analytical methods need much labor and time for these analyses. In order to compensate for this problem  we used near infrared spectroscopy technology to measure the chemical-composition of soy sauce. In the course of the work  a certain amount of soy sauce was collected and was analyzed by wet chemistry analytical methods. The soy sauce was scanned by two kinds of the spectrometer  the Fourier Transform near infrared spectrometer (FT-NIR spectrometer) and the filter near infrared spectroscopy analyzer. The near infrared spectroscopy of soy sauce was calibrated with the components of wet chemistry methods by partial least squares regression and stepwise multiple linear regression. The contents of saltless soluble solids  total nitrogen  total acid and nitrogen of amino acids were predicted by cross validation. The results are compared with the wet chemistry analytical methods. The correlation coefficient and root-mean-square error of prediction (RMSEP) in the better prediction run were found to be 0.961 and 0.206 for total nitrogen  0.913 and 1.215 for saltless soluble solids  0.855 and 0.199 nitrogen of amino acids  0.966 and 0.231 for total acid  respectively. The results presented here demonstrate that the NIR spectroscopy technology is promising for fast and reliable determination of major components of soy sauce.  
Study of dynamic response on a MOEMS 22 optical switch (EI CONFERENCE) 会议论文  OAI收割
Optical Transmission, Switching, and Subsystems II, November 9, 2004 - November 11, 2004, Beijing, China
作者:  
Wang G.;  Chen W.
收藏  |  浏览/下载:30/0  |  提交时间:2013/03/25
The MOEMS 22 optical switch with slant lower electrode and with torsion beam on silicon is designed and analyzed theoretically. Analytical formulae for the squeeze film damping coefficient and the squeeze film damping moment on the cantilever beam of the optical switch are derived. Based on the torsion dynamics theory  the technique and relative results are presented for analyzing the actuating voltage and the switch time. The optimized result of parameters is as: length  width and thickness of the torsion beam are 700  12 and 10 m  length and width of the cantilever beam are 1900 and 1000 m  length and width of the balance beam are 100 and 1000 m  shortest spacing between the upper and lower electrodes is 0.05 m  and highness of the lower electrode is 55 m  respectively. The actuating voltage is less than 10 V  and the switching time of Ton and Toff are 1.30ms and 1.25ms  respectively. The computed results show that the air squeeze film damping is an important factor for the study of dynamic response on MOEMS optical switch.  
Imaging quality analysis of KBA x-ray microscope working at grazing incidence (EI CONFERENCE) 会议论文  OAI收割
Optical Design and Testing II, November 8, 2004 - November 11, 2004, Beijing, United states
作者:  
Zhao L.
收藏  |  浏览/下载:27/0  |  提交时间:2013/03/25
In the latest 20 years  x-ray imaging technology has developed fast in order to meet the need of x-ray photo-etching  spatial exploration technology  high-energy physics  procedure diagnosis of inertial confinement fusion (ICF) et al. Since refractive index of materials in the x-ray region is lower than 1  and x-ray is strongly absorbed by materials  it is very difficult to image objects in the x-ray region. Conventional imaging methods are hardly suitable to x-ray range. In general  grazing reflective imaging and coding aperture imaging methods have been adopted more and more. In this paper  according to user's requirement  we have designed a non-coaxial grazing KBA microscope. The microscope consists of two sets of perpendicular spherical mirrors  each set includes two parallel mirrors. Taking it as an example  we have compiled an optical computing program for the non-coaxial grazing imaging systems so as to analyze and evaluate aberrations of KBA microscope. Thus it can help us to get an optimal comprehension of KBA x-ray imaging system. In the same time  the analytical results provide reliable foundation for evaluating imaging quality of KBA microscope.  
  • 首页
  • 上一页
  • 1
  • 下一页
  • 末页