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	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：43/0 \| 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.
	Design and test of pointing mirror assembly for spaceborne remote sensing camera (EI CONFERENCE) 会议论文 OAI收割 2011 International Conference on Electronics, Communications and Control, ICECC 2011, September 9, 2011 - September 11, 2011, Ningbo, China 作者: Chen W. 收藏 \| 浏览/下载：35/0 \| 提交时间：2013/03/25 In order to ensure the surface figure of the pointing mirror (460mm long 290mm wide) in spaceborne remote sensing camera Silicon Carbide was selected as the mirror material. The form of composite triangular and rectangular and the combination of open and closed back was explored in the lightweight design. A new kinematic mount and flexible structure in axis is used to hold the mirror around the lateral surface. The structure can minimize distortions induced by coefficient of thermal expansion mismatch among the materials. This eliminates the bending of the integral mount under the weight of the mirror. Optical performance of the mirror was analyzed under gravity load and temperature load using finite element method. Predicted surface figure error based on the removal of bias tilt and power was calculated using an in-house Matlab script for mirrors. The pointing mirror assembly was tested using open loop servo control. And the surface figure was checked using interferometer. Surface figure accuracy is better than 1/30 ( 632.8nm rms). The results show that the kinematic mount induces minimal figure error on the optical surface. 2011 IEEE.
	Effect of additives on the properties of plasma electrolytic oxidation coatings formed on AM50 magnesium alloy in electrolytes containing K(2)ZrF(6) 期刊论文 OAI收割 Surface & Coatings Technology, 2011, 卷号: 206, 期号: 2-3, 页码: 455-463 F. Liu; D. Y. Shan; Y. W. Song; E. H. Han 收藏 \| 浏览/下载：26/0 \| 提交时间：2012/04/13 PEO coating Magnesium Anodizing Corrosion resistance Electrolytes electrochemical corrosion behavior microarc oxidation lightweight materials composite coatings ceramic coatings mg alloy az91d resistance silicate surface
	Corrosion behavior of the composite ceramic coating containing zirconium oxides on AM30 magnesium alloy by plasma electrolytic oxidation 期刊论文 OAI收割 Corrosion Science, 2011, 卷号: 53, 期号: 11, 页码: 3845-3852 F. Liu; D. Y. Shan; Y. W. Song; E. H. Han; W. Ke 收藏 \| 浏览/下载：21/0 \| 提交时间：2012/04/13 Magnesium SEM XRD XPS Oxide coatings microarc oxidation lightweight materials az91d films resistance silicate mao microstructure performance
	Research on automatic Hartmann test of membrane mirror (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 P. 收藏 \| 浏览/下载：31/0 \| 提交时间：2013/03/25 Electrostatic membrane mirror is ultra-lightweight and easy to acquire a large diameter comparing with traditional optical elements so its development and usage is the trend of future large mirrors. In order to research the control method of the static stretching membrane mirror the surface configuration must be tested. However membrane mirror's shape is always changed by variable voltages on the electrodes and the optical properties of membrane materials using in our experiment are poor so it is difficult to test membrane mirror by interferometer and null compensator method. To solve this problem an automatic optical test procedure for membrane mirror is designed based on Hartmann screen method. The optical path includes point light source CCD camera splitter and diffuse transmittance screen. The spots' positions on the diffuse transmittance screen are pictured by CCD camera connected with computer and image segmentation and centroid solving is auto processed. The CCD camera's lens distortion is measured and fixing coefficients are given to eliminate the spots' positions recording error caused by lens distortion. To process the low sampling Hartmann test results Zernike polynomial fitting method is applied to smooth the wave front. So low frequency error of the membrane mirror can be measured then. Errors affecting the test accuracy are also analyzed in this paper. The method proposed in this paper provides a reference for surface shape detection in membrane mirror research. 2010 Copyright SPIE - The International Society for Optical Engineering.
	Barium phosphate conversion coating on die-cast AZ91D magnesium alloy 期刊论文 OAI收割 Transactions of Nonferrous Metals Society of China, 2008, 卷号: 18, 页码: S344-S348 F. Liu; D. Y. Shan; E. H. Han; C. S. Liu 收藏 \| 浏览/下载：25/0 \| 提交时间：2012/04/13 barium phosphate conversion coating die-cast AZ91D magnesium alloy micro-cracks corrosion resistance lightweight materials corrosion-resistance
	Fabrication technique of large-scale lightweight SiC space mirror (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 作者: Zhang G.; Zhang G.; Zhang G. 收藏 \| 浏览/下载：20/0 \| 提交时间：2013/03/25 Silicon carbide (SiC) is a new type candidate material for large-scale lightweight space mirror. Its low thermal distortion high stiffness high optical quality and its dimensional stability are better than other traditional optical substrate materials such as ULE Zerodure Beryllium (Be) and so on. In this paper the lightweight silicon carbide space mirror blank was fabricated by reaction sintering. As a space born mirror material silicon carbide must be an optical grade ceramic. So we prepared the silicon carbide green body with gel-casting method. Then some carbon materials were supplemented into the green body which will bring reaction-sintering with silicon in a vacuum furnace during 1500-1600C ultimately the reaction bonded silicon carbide was made. The diameter of SiC space mirror blank we have made is 680mm. If expanding the size of the vacuum furnace bigger mirror blank can be obtained. The test results show that the mechanical and thermal properties of RB-SiC are excellent with bending strength of 350MPa fracture toughness of 4.1 MPa·m1/2 and coefficient of thermal expansion(CET) of 2.6710-6/K. The surface roughness(RMS) could be better than 3nm.