中国科学院机构知识库网格系统: 检索

Modelling of the electric field assisted capillarity effect used for the fabrication of hollow polymer microstructures (EI CONFERENCE) 会议论文 OAI收割
2012 13th International Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Microsystems, EuroSimE 2012, April 16, 2012 - April 18, 2012, Cascais, Portugal
Tonry C.; Patel M.; Bailey C.; Desmuliez M. P. Y.; Cargill S.; Yu W.

收藏 | 浏览/下载：93/0 | 提交时间：2013/03/25

Electric Field Assisted Capillarity (EFAC) is a novel process which has the potential for the single step fabrication of hollow polymer microstructures. The process has been shown to work experimentally on a microscale level using Polydimethylsiloxane (PDMS). The process makes use of both the electrohydrodynamics of polymer at a microscale and the voltage enhanced capillary force exerted on the polymer. This paper discusses the results of a two-dimensional numerical simulation of this process. The results presented use a patterned master electrode producing encapsulated microchannels in the polymer. The simulations demonstrate how the differing contact angles between the polymer and the walls of the master electrode affect the thickness of the top surface of the formed microstructures. It also specifies the conditions necessary for the successful fabrication of such microstructures. 2012 IEEE.

Research on computer control strategy for optical electric tracking system (EI CONFERENCE) 会议论文 OAI收割
2011 IEEE International Conference on Mechatronics and Automation, ICMA 2011, August 7, 2011 - August 10, 2011, Beijing, China
作者: Li M.

收藏 | 浏览/下载：23/0 | 提交时间：2013/03/25

In this paper mathematic model and computer control strategy for optical electrical tracking system have been researched and discussed. First the system's structure and its work process have been analyzed. Second according to the system's moving law the system's mathematic model has been built. As to the computer control strategy trigger guiding two closed loop PID control method as well as compound control method have been applied to satisfy the tracking accuracy. Third we apply the bilinear transformation to get the digital system and the sample time is 800Hz. The simulation results indicate that the maximum tracking error can be limited to less than 0.5 and the regulator time can be 0.04s. Then the control project resonance frequency should be more than 200Hz and the sample frequency should be more than 400Hz to meet the control accuracy requirement. So we can conclude that the system indexes such as swiftness high accuracy as long as real time have been satisfied. And the requirement of mechanical property has been present which is very useful to mechanical working. 2011 IEEE.

Optimum design of the carbon fiber thin-walled baffle for the space-based camera (EI CONFERENCE) 会议论文 OAI收割
International Symposium on Photoelectronic Detection and Imaging 2011: Space Exploration Technologies and Applications, May 24, 2011 - May 26, 2011, Beijing, China
Yan Y.; Gu S.; An Y.; Jin G.

收藏 | 浏览/下载：14/0 | 提交时间：2013/03/25

The thin-walled baffle design of the space-based camera is an important job in the lightweight space camera research task for its stringent quality requirement and harsh mechanical environment especially for the thin-walled baffle of the carbon fiber design. In the paper an especially thin-walled baffle of the carbon fiber design process was described and it is sound significant during the other thin-walled baffle design of the space camera. The designer obtained the design margin of the thin-walled baffle that structural stiffness and strength can tolerated belong to its development requirements through the appropriate use of the finite element analysis of the walled parameters influence sensitivity to its structural stiffness and strength. And the designer can determine the better optimization criterion of thin-walled baffle during the geometric parameter optimization process in such guiding principle. It sounds significant during the optimum design of the thin-walled baffle of the space camera. For structural stiffness and strength of the carbon fibers structure which can been designed the effect of the optimization will be more remarkable though the optional design of the parameters chose. Combination of manufacture process and design requirements the paper completed the thin-walled baffle structure scheme selection and optimized the specific carbon fiber fabrication technology though the FEM optimization and the processing cost and process cycle are retrenchment/saved effectively in the method. Meanwhile the weight of the thin-walled baffle reduced significantly in meet the design requirements under the premise of the structure. The engineering prediction had been adopted and the related result shows that the thin-walled baffle satisfied the space-based camera engineering practical needs very well its quality reduced about 20% the final assessment index of the thin-walled baffle were superior to the overall design requirements significantly. The design method is reasonable and efficient to the other thin-walled baffle that mass and work environment requirement is requirement harsh. 2011 SPIE.

Grayscale control algorithm based on optokinetic nystagmus (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
Chen Y.-S.; Gao H.-B.; Su W.-X.; Wang M.

收藏 | 浏览/下载：22/0 | 提交时间：2013/03/25

In order to reduce trailing phenomenon for moving image in FPD (Flat Panel Display) Then Finally grayscale control algorithm is proposed that simulates CRT (Cathode Ray Tube) grayscale rendition process. First based on algorithm derivation implemented main program with VHDL (Very-High-Speed Integrated Circuit Hardware Description Language) is presented and specific rendition process is described. Experimental results indicate image quality is evidently improved and proposed algorithm reduces trailing phenomenon nearly 90% after the reason of trailing phenomenon for moving image is introduced algorithm realization steps and compared experiment results of traditional and proposed FPD grayscale control algorithm are discussed when FPD displays moving image work processes of human eyes are illuminated and grayscale rendition of a pixel is obtained according with eyes reflection mechanism and programs can correctly implement on circuit board. 2010 IEEE. when seeing moving image on CRT and FPD

1D-KBA microscope using double-periodic multilayer (EI CONFERENCE) 会议论文 OAI收割
Advances in X-Ray/EUV Optics and Components IV, August 3, 2009 - August 5, 2009, San Diego, CA, United states
作者: Wang Z.; Wang X.; Wang X.; Wang X.; Wang Z.

收藏 | 浏览/下载：11/0 | 提交时间：2013/03/25

To study the action of shock wave in CH target one-dimensional grazing incidence KBA microscope for 4.75keV energy was set up. Because of strong absorption in air 4.75keV energy microscope can just work in vacuum. Accordingly the alignment and assemblage will be very complicated and difficult. A special multilayer method using double periodic multilayer was proposed to solve this problem. This multilayer has high reflectivity not only for 4.75keV X-rays but also for 8keV X-rays at the same grazing incidence angle. It means 1D-KBA microscope has the same light trace for different working energies. Therefore we can implement the alignment and assembly of 4.75keV system by the help of 8keV X-rays. Because 8keV X-rays is very easy produced by X-ray tube and has strong transmittability in air the alignment and assemblage process became relatively easy. By now we have finished the alignment experiment at 8keV and obtained imaging results. The performance is about 2-3m resolution in 250m field of view. It is coincide with the calculation. 2009 SPIE.

The automatic photoresist coating machine on the spherical surface (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: Li Y.; Li Y.; Li Y.; Li Y.; Wang H.

收藏 | 浏览/下载：21/0 | 提交时间：2013/03/25

The photoresist coating is an important micro machining process widely applied in engineering. The formed film should be uniform and enough thin to assure the quality of final pattern whose line width is micrometer or nanometer. It is more difficult to process it on the spherical surface than on the flat. In this work mathematic model of film thickness on the spherical surface is proposed by using hydromechanics. The key factors that influence the film thickness are obtained from the analysis of coating process. Then the rational parameters which be controlled by the automatic photoresist coating machine can be final set up according to the result of the coating experiments. And the accuracy analysis of the key part which is used for the main process is performed by the error analytics. This machine not only makes the whole coating process automation but also monitors the film quality in real time. It is adequate for aspheric surface also. 2009 IEEE.

Monte Carlo simulation of light propagation in human tissue models (EI CONFERENCE) 会议论文 OAI收割
3rd International Conference on Bioinformatics and Biomedical Engineering, iCBBE 2009, June 11, 2009 - June 13, 2009, Beijing, China
作者: Wang Z.; Wang L.; Wang L.; Wang L.; Wang Z.

收藏 | 浏览/下载：35/0 | 提交时间：2013/03/25

In this paper in order to be more sensitive to the volumetric changes of capillaries in the skin the photon propagation process in human brain tissue and skin tissue with various source and detector separation distances were simulated based on the Monte Carlo method. The human brain model and the skin model that were used in our experiments have five layers and seven layers the separation distance of source and detector should be approximately eight millimeters. Future work was discussed at the end of the paper. 2009 IEEE. respectively. The backscattered intensity from every layer of the human tissue model was obtained by marking the deepest layer that every photon can reach. The simulation results of brain model indicated that the source-detector separation distance should be selected at three centimeters for studies on the actions of the brain nerve cells

Application of CMOS APS star tracker with large FOV in attitude and angular velocity determination (EI CONFERENCE) 会议论文 OAI收割
Advanced Sensor Systems and Applications III, November 12, 2007 - November 14, 2007, Beijing, China
Lu D.; Guang J.; Shaoju W.; Tao C.

收藏 | 浏览/下载：30/0 | 提交时间：2013/03/25

The paper deals with the spacecraft attitude determination problem using a new kind of star tracker with large FOV based on CMOS APS. Star tracker has been developed since 1970s and proved to be the most accurate sensor ever used in the spacecraft attitude determination systems. But the traditional CCD star tracker also has some disadvantages such as small FOV high power consumption low sample rate and low working angular rate limit which prevent the use of CCD star tracker in attitude large angle maneuvering process. The new kind of star tracker based on CMOS APS has no such disadvantages and is more applicable on modern low-cost agile small satellites. Its higher sample rate and working angular rate limit over traditional CCD star tracker make it more adapt for spacecraft angular velocity determination. Because of the large FOV of the star tracker the mathematical model of traditional CCD star tracker with a small FOV is not appropriate. So a new mathematical model was quoted to fit the star tracker with a large FOV. An alternative adaptive algorithm was also introduced in the paper. It can help the EKF algorithm work lacking of accurate covariance of the observation noise. An optimal estimation algorithm was used to estimate the angular velocity directly from the star tracker measurements. Mathematic simulation results indicate the CMOS APS star tracker can give accurate attitude information and estimated angular rate. The method can be used as the chief attitude determination system design of low-cost satellite without gyros or be used as a backup strategy in the event of gyro failures to enhance the reliability of the attitude determination system.

Modeling and analysis of a supply-assembly-store chain 期刊论文 OAI收割
EUROPEAN JOURNAL OF OPERATIONAL RESEARCH, 2007, 卷号: 176, 期号: 1, 页码: 275-294
作者: Zhao Xiaobo; Xu, Deju; Zhang, Hanqin; He, Qi-Ming

|

收藏 | 浏览/下载：32/0 | 提交时间：2018/07/30

supply chain mixed model assembly line Markov chain work-in-process inventory service level

Study of microsphere plate photomultiplier tube (EI CONFERENCE) 会议论文 OAI收割
ICO20: Remote Sensing and Infrared Devices and Systems, August 21, 2005 - August 26, 2005, Changchun, China
作者: Wang X.; Li Y.; Li Y.; Li Y.; Li Y.

收藏 | 浏览/下载：32/0 | 提交时间：2013/03/25

The photomultiplier tube (PMT) that can work in different wavelength is an important detector device in remote sense technology. Microsphere plate using glass beads 50to 70m in diameter sintered together is the core component of the microsphere plate photomultiplier tube It is a novel two-dimension electron multiplier. The electrons gain for a single plate is about 1017 and do not have the phenomenon of ion-feedback. Furthermore the fabrication process is very easy. In this paper much interest was put on the microsphere plate photomultiplier tube. Based on the analyses from the theory and the experiment result we point out the key technology for fabricating PMT is how to obtain glass beads with narrow range in diameter and how to sinter the glass beads with a sufficient pylome. Factors affect the gradating technology and sintering process along with the solution to them is presented. In the last the structure scheme and technological characteristic for fabricating microsphere plate photomultiplier tube were given. The pulse rising-time of MSP-PMT is below 400ps suitable to the detection of high-speed pulse. As easy to be fabricated and has great advantage over MCP multiplier in the ratio of performance to price the microsphere plate photomultiplier tube is a promising dim-light detector.