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	Astronomical image restoration through atmosphere turbulence by lucky imaging (EI CONFERENCE) 会议论文 OAI收割 3rd International Conference on Digital Image Processing, ICDIP 2011, April 15, 2011 - April 17, 2011, Chengdu, China 作者: Zhao J.; Wang J.; Zhang S. 收藏 \| 浏览/下载：28/0 \| 提交时间：2013/03/25 In this paper we develop a lucky imaging system to restore astronomical images through atmosphere turbulence. Our system takes very short exposures on the order of the atmospheric coherence time. The rapidly changing turbulence leads to a very variable point spread function (PSF) and the variability of the PSF leads to some frames having better quality than the rest. Only the best frames are selected aligned and co-added to give a final image with much improved angular resolution. Our system mainly consists of five parts: preprocessing frame selection image registration image reconstruction and image enhancement. Our lucky imaging system has been successfully applied to restore the astronomical images taken by a 1.23m telescope. We have got clear images of moon surface and Jupiter and our system can be demonstrated to greatly improve the imaging resolution through atmospheric turbulence. 2011 Copyright Society of Photo-Optical Instrumentation Engineers (SPIE).
	Application of Moldflow in gas-assisted injection molding (EI CONFERENCE) 会议论文 OAI收割 2011 International Conference on Mechatronics and Materials Processing, ICMMP 2011, November 18, 2011 - November 20, 2011, Guangzhou, China Zi K. M.; Chen L. H. 收藏 \| 浏览/下载：28/0 \| 提交时间：2013/03/25 Gas-assisted injection molding(GAIM)is a new kind of plastic processing technique. It is one of the most important developments in the injection molding industry. GAIM has many advantages such as lower injection pressure lower warpage better surface quality lower material consumption and shorten molding cycle time etc. MPI/Gas module of Moldflow software can be used to simulate the GAIM process to optimize the whole molding process. In this study the FM new truck interior ceiling handle was analyzed in GAIM process based on the MPI/Gas module. The simulation results showed the gas penetrating time the contours of plastic layers thickness fraction of the parts and the gas volume fraction changing with time. The results can help technicians to determine the optimum process of the melt injection and the gas injection to ensure the final quality of the parts. 2011 Trans Tech Publications.
	Study on experiment of grinding SiC mirror with fixed abrasive (EI CONFERENCE) 会议论文 OAI收割 4th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Advanced Optical Manufacturing Technologies, November 19, 2008 - November 21, 2008, Chengdu, China 作者: Wang X.; Zhang X.-J.; Wang X.; Wang X. 收藏 \| 浏览/下载：23/0 \| 提交时间：2013/03/25 A brand-new technology for manufacturing SiC reflecting mirror that is different from the traditional method is adopted which is called as fixed abrasive surfacing technology. Not only the new method achieves better mirror quality with bigger diamond in diameter quickly but also because of the fixed motion between the abrasive and workpiece and it will be good for surface finishing. During experiment material removal characteristic which is on SiC under certain rotation speed and pressure by W7 W5 W3.5 W1.5 pellets has been tested. Through those removal curves we come to a conclusion that the technology not only has a higher removal rate but also has much more stability. In addition the surface roughness experiment is mentioned. In the first stage we achieved a mirror with surface roughness 42.758nm rms with W7 pellets. The surface roughness is descending as we change pellets with smaller diamond in diameter . At the end of experiment a smooth surface with roughness 1.591nm rms has been achieved after using W1.5 pellets. Experiment results indicate that the technology which manufactures SiC reflecting mirror with fixed abrasive is able to replace the traditional slurry abrasive completely in certain finishing phase and also has a great foreground in application. 2009 SPIE.
	Configuring an electrostatic membrane reflector with potentials exerted on distributed electrodes (EI CONFERENCE) 会议论文 OAI收割 2009 IEEE International Conference on Mechatronics and Automation, ICMA 2009, August 9, 2009 - August 12, 2009, Changchun, China 作者: Zhang P.; Shi G. 收藏 \| 浏览/下载：19/0 \| 提交时间：2013/03/25 Electrostatic membrane reflector (EMR) is very promised for optical quality application with the merits of utra-lightweight and flexible. Configuring a circular membrane reflector with electrostatic potentials exerted on distributed electrodes can approximatively produce a parabolic shape. A 300mm EMR (made from polyimide) stretched by distributed electrodes below is designed and the number of concentric electrodes needed for membrane shape forming is analysed. First based on an analytical solution of Poisson's equation determine the membrane control matrix by finding influence functions of 3 concentric electrodes and 6 control points on membrane surface in order to compute the needed voltages exerted on the distributed electrodes by the method of least-squares fitting. Then the final shape solved by finite element analysis with ANSYS is contrasted with the paraboloid and deviates greatly when the central displacement of membrane is beyond 2.5mm but in this range increasing the number of electrodes and control points will get a better shape. The corresponding errors are analyzed and the control method is concluded. Only using the integrated method of analytical computation numerical analysis and experiment the membrane shape of certain central displacement can be exactly predicted and controlled. 2009 IEEE.
	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：21/0 \| 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.