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浏览/检索结果: 共3条，第1-3条 帮助 限定条件 发表日期：2009     已选(0)清除 条数/页：5101520253035404550556065707580859095100   排序方式：请选择作者升序作者降序题名升序题名降序发表日期升序发表日期降序提交时间升序提交时间降序 Modeling and analysis of dialyte-lens auto-focusing technology for theodolite (EI CONFERENCE) 会议论文 2008 International Conference on Optical Instruments and Technology: Optoelectronic Measurement Technology and Applications, November 16, 2008 - November 19, 2008, Beijing, China Wu L.-T.; Qiao Y.-F.; Wu D.-K.; Cai S. 收藏  |  浏览/下载：14/0  |  提交时间：2013/03/25 In order to realize real-time auto-focusing for theodolite  lens-apart method was designed with the corresponding math model built and analyzed. An Object beam splitted after the first image surface of the theodolite traveled through two dialyte lens and then was imaged on CCD. The distance between two spots when exactly focused was set as the calibration value  and the relationship between defocus distance and spot offset was given. The influence of tracking center shift and divergence angle etc. on focusing accuracy was analyzed. Compared with the traditional focusing method  this scheme has a higher accuracy  faster calculation  higher tolerance for environment temperature and a simpler construction. The experiment result exhibited a resolution higher than 0.056mm  which shows a bright engineering application prospect for this method. 2009 SPIE.   Estimation algorithm of mobile OFDM CFOs based on step-size (EI CONFERENCE) 会议论文 2009 International Conference on Information Engineering and Computer Science, ICIECS 2009, December 19, 2009 - December 20, 2009, Wuhan, China Lin L.; Qiao Y.-F.; Su W.-X. 收藏  |  浏览/下载：20/0  |  提交时间：2013/03/25 In order to maintain orthogonality among subcarriers for mobile OFDM  a CFOs step-size estimation model is established to avoid severe performance degradation caused by ICI  and algorithmic stability  step-size parameter  the error of CFOs estimate and etc are investigated. First  after an averaging window algorithm is introduced  the mathematic model of step-size estimation algorithm is obtained through step-size parameter and time-varying CFOs. Then  based on the results of MATLAB simulation  the determination of step-size parameter  the advantages of step-size algorithm and precision are discussed. Finally  time sequence plots of added CP  interleaver and subcarrier modulation with VHDL are presented. Experimental results indicate that the maximum of CFOs errors is 0.00987 in 3 variance interval  when mobile velocity is 400 km/h  according with verdicted principle that in order for the ICI effects to be negligible  the error of CFOs estimation must be accurate within 1-2% of the subcarrier spacing  and programs can correctly implement on circuit board. 2009 IEEE.   A sensitive solid-phase time-resolved fluorescence immunoassay apparatus (EI CONFERENCE) 会议论文 International Symposium on Photoelectronic Detection and Imaging 2009: Laser Sensing and Imaging, June 17, 2009 - June 19, 2009, Beijing, China Wang Y.-L.; Song K.-F.; Zhang W.-L.; Li J.-L. 收藏  |  浏览/下载：25/0  |  提交时间：2013/03/25 In the device  a He-Ne laser of flash frequency 1-20 Hz was adopted as exciting light source  and three key technical problems have been solved successfully in order to enhance the detecting sensitivity and measuring stability of the device for time-resolved fluorimmunoassays(TRFIA) [1]. The first one is to design optimum exciting optical system  so that the exciting light beam excite the sample most effectively. The second one is to have a project spectrum filter which can reduce the affection of the background light to the photomultiplier tube and also ensure influence of the stray light and mixed diffusion light to the sample fluorescence to the least  the sample fluorescence through the integrating sphere and come to the grating monochromator  The right wavelength will be chosed through changing the angle of incidence of the grating monochromator. The third one is to simulate the principle of sample averaging of BOXCAR averager. In the device  SCM was used as primary controller and CPLD was used as timing controller. Through the preparation process  signal-to-noise ratio(SNR) will be improved  also adjust delay time  ampling frequency and sampling number arbitrarily. By testing  the sensitivity is 10-12mol/L(substance marked by Eu3+)  examination repeat is &le2.5%  examination linearity is from 10 -8mol/L to 10-12mol/L  correlation coefficient is 99.98%(p&le0.01). The instrument is advanced for ultrasensitive detection of antigen and antibody  and solve the tumor  genetic variation  the virus protein detection. 2009 SPIE.