基于线阵CCD的图像采集系统设计

介绍了一种快速提取边缘特征信息的图像采集系统设计方法。该方法以C8051f060单片机为控制核心, 结合外围环形硬件电路实现对线阵CCD图像传感器的驱动,采用简单的预处理电路将两路CCD输出信号转变为一路可利用的视频信号,再利用单片机的A/D转换模块对视频信号进行模数转换和串口通信将数字图像数据发送到上位机等待后续处理。该系统电路设计较简单,集成度高,成本低,避免了以往设计方法的不足,通过实验结果表明：该系统具有较好的抗干扰性和稳定性,产生的驱动信号符合CCD工作需求,可以快速、高效完成对含有边缘特征信号的采集并实现高精度测量。     

采用AVR控制器的GPS授时与定位装置的设计与制作

本文以解析GPS的时间信息和位置信息为目标,通过使用嵌入式GPS模块和AVR控制器,设计和制作GPS授时与定位装置,实现时间信息和位置信息的解析和显示等问题。本文首先给出了基于GPS模块和AVR控制器的授时与定位装置的整体构架,然后对各个部分的 硬件进行详细设计,给出了硬件设计电路和软件设计框图。最后对所设计的基于GPS模块和AVR控制器的授时与定位装置进行实物制作,证明了设计内容的正确性和可行性,具有一定的实际应用价值。     

视频监控系统中双路视频字符叠加器设计与实现

根据视频信号字符叠加原理,针对现有设计不能图文并茂且叠加字符有限的不足,基于MB90092芯片提出一种同时实现两路字符叠加的设计方案.对该方案进行理论分析,并设计电路.通过实验,验证了方案的有效性和可靠性.     

基于单片机的自供电供暖温度智能调控装置

设计了一种自供电的供暖调控装置,其主要包括温差供电模块、电路控制模块、水流控制模块。本装置工作时,温差供电模块可利用暖气管道与室温的温差发电,以STC89C52单片机为核心的电路控制模块可实时监测室内温度,并能根据用户设定温度和室内实际温度驱动水流控制模块,以调控供暖管道水流量,从而达到调节室内温度的目的。     

基于CMOS图像传感器的微型无人机遥感系统设计

为了实现微小型无人机航空遥感,设计了一种基于CMOS图像传感器的微小型无人机的可见光遥感系统.系统采用CMOS图像传感器替代CCD,利用时序发生模块(Field-Prog Rammble Array,FPRA)实现了控制时序、数据缓存和硬件彩色插值,C8051F单片机作为主控核心,采用FLASH作为数据存储单元,设计了PAL制视频信号生成电路.介绍了所用CMOS图像传感器的特性,分析了Bayer颜色格式进行彩色插值恢复标准RGB颜色格式的硬件实现与软件算法.整个系统重量约20 g,功耗约2 W.在一款翼展800 mm的无人机上实现了遥感拍照,给出了处理后的拍照结果.     

高速Cameralink视频信号的光纤传输系统设计

针对目前常用的Cameralink视频信号的光纤传输方案系统结构过于复杂的问题,提出一种基于MAX9249/MAX9268的Cameralink视频信号的光纤传输方案。在发送端利用MAX9249实现Cameralink视频信号解串行化、编码、串行化,得到光模块驱动信号CML;在接收端利用MAX9268实现CML信号解串行化、解码、串行化,得到Cameralink视频信号,并对光收发模块的设计与选型作了详细阐述。用示波器抓取发送端和接收端高速串行信号的眼图,结果比较清晰,眼睛张开度大,发送端的Q因子为24.46,满足发送端大于12的要求,接收端Q因子为8.13,满足接收端大于6的要求。计算机采集的实时画面,经过10 min传输无明显可视的像素噪点,验证了该传输方案的可行性和有效性。     

基于TMS320DM642芯片的视频目标跟踪系统设计与实现

运动目标的检测与跟踪一直是在计算机视觉的研究领域占有重要位置,该技术被越来越广泛的应用到交通管理、军事、公共安全监控等领域中;文章主要研究基于TMS320DM642开发平台的视频运动物体目标的检测与跟踪,文章分为软硬件两部分进行设计,硬件部分主要包含视频采集模块、视频处理模块以及显示模块3个部分,通过CCD摄像头采集视频信号,接着将采集的模拟视频信号传输到SEED VPM642视频处理模块,在VPM642中通过高性能视频解码器TVP5150将模拟视频信号转换成BT.656格式的视频信号,并将该信号传输给DM642的视频接口;在系统软件部分,系统采用TI的DSP集成开发环境CCS2.2作为系统软件开发平台,最终在DM642视频图像处理平台上实现运动目标的实时检测与跟踪;实验结果表明,该文提出的算法移植和优化方法效果明显,可以在DSP开发平台上实现运动目标的实时检测与跟踪。     

一种用于fMRI的温度觉刺激装置的设计与验证

介绍了一种用于功能磁共振成像(f MRI)的温度觉刺激装置的设计与验证,该装置能够用于f MRI温度觉的脑功能研究,满足温度觉f MRI实验的自动化刺激要求.整个刺激装置设计了以微控制器为核心的控制电路,通过数据采集卡能够与上位机Lab VIEW软件进行数据通讯,并将获取的数据通过特定的串口协议传递给数字PID温控模块,实现对刺激端温度的精确调控.最后,使用该刺激装置对多名被试进行了温度觉的脑功能实验,实验结果验证了该设计的可行性.     

一种新的蔡氏电路设计方法与硬件实现

提出了一种基于蔡氏无量纲状态方程新的电路设计方法.首先对蔡氏无量纲状态方程各变量进行比例压缩变换、微分-积分转换和时间尺度变换.其次根据变换后的方程设计出各模块电路，再将各模块按方程中各状态变量的对应关系联结起来.整个电路只由反相加法器、积分器和反相器三大模块构成，电路结构对称.与现有其他的混沌电路设计相比，该方法具有三个主要特点：(1)直观性强，实现了电路的模块化设计，并总结出了这类混沌电路更一般的设计原理，具有普适性，可用于其他无量纲连续状态方程的电路设计；(2)由于采用了反相加法器，各个电路参数独立 关键词： 蔡氏电路 多项式 模块化设计 硬件实验     

LTD模块串联装置中部分模块不工作时的输出性能

基于10级模块串联的1 MV快脉冲直线型变压器驱动源装置,分别开展了1～3个模块在不充电或不触发时装置的整体输出参数测试。结果表明,在二极管负载阻抗基本不变的情况下,装置输出电流和电压降低的数值约为故障模块数与总模块数的比值。与所有模块正常工作时相比,脉冲上升时间分别增加10,22和32 ns,脉冲宽度分别增加13,23和48 ns。根据电路分析以及模块实际电参数建立了装置的等效电路模型,模拟得到的不同数量模块不工作时的输出电压变化趋势与实验结果基本一致,并利用电路模型对故障模块中开关两端的电压进行了模拟和分析。     

Guided-Wave Two-Dimensional Acousto-Optic Scanner Using Proton-Exchanged Lithium Niobate Waveguide

Two-dimensional scanning of a 0.6328 mum guided-light beam has been realized using noncolinear acousto-optic (AO) coplanar Bragg diffraction together with colinear AO guided-mode to substrate radiation-mode conversion in a Z-cut Xpropagation LiNbO3 proton-exchanged (PE) waveguide. The two surface acoustic (SAW) waves utilized are at the center frequencies of 500 and 200 MHz, propagating in the Y and X axes, respectively. Two-dimensional scanning of approximately 720 resolvable light beam spots, namely, 18 40 (horizontal vertical) scanning, has been demonstrated using a light beam of 1.0 mm aperture. The total number of resolvable beam spots can be greatly increased from 720 by simply utilizing SAW transducers of larger bandwidth and a light beam of greater aperture. It should also be possible to significantly increase the diffraction efficiency from 3 % by optimizing the parameters of the PE waveguide and the SAWs.     

Femtosecond Transform-Limited Pulse Generation by Compensating for the Linear Chirp of SPM Spectra in Dispersion Shifted Fibers

A simple technique of pulse compression, based on the linear chirp compensation of self-phase modulation (SPM) spectra in dispersion shifted fibers, is demonstrated. The optimization procedure is carried out, for a short span of a single-mode fiber, using a parabolic law, which describes the behavior of the squared output pulse width versus the pump peak power in the case of Gaussian pulses. The experimental results give a minimum pulse duration of 233 fs, which is in good agreement with the model. Shorter and coherent pulses, down to 90 fs, have been obtained by inserting an interference filter at the optical output.     

Effect ofγ-radiation on the spectral luminescence characteristics of impure cadmium tungstate crystals

Results of a study of the effect of γ-radiation on the spectral luminescence properties of cadmium tungstate crystals doped with silver, bismuth, and molybdenum cations are presented. Spectral characteristics of the nondnnnoped crystals are briefly described. Absorption and photo and X-ray luminescence spectra of the crystals taken before and after exposure to γ-radiation (5.5·10⁴ Gy) are compared. It is found that the spectral characteristics of the crystals doped with silver, bismuth, and molybdenum cations do not change markedly after the exposure. The relation between the type of impurity-induced defects, individual characteristics of the impurity cations, and the character of the effect of γ-radiation on the spectral luminescence properties of impure crystals is analyzed (preliminarily). Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 64, No. 1, pp. 55–60, January–February, 1997.     

Theoretical analysis and simulation of conjugate heights for dual-conjugate AO system in lidar

A multi-conjugate adaptive optics （MCAO） can offer a possibility of widening field of view （FOV） characterized by the isoplanatic angle, and the choose of conjugate height becomes a basic problem for MCAO, which influences the size of iosplanatic angle. Considering the application of lidar, the isoplanatic angle＇s expressions of two deformable mirrors （DMs） MCAO for uplink and downlink are deduced. The effects of conjugate heights for dual-conjugate AO are thoughtfully discussed, and the isoplanatic angles are further analyzed. The results show that the isopanatic angle varies with the conjugate height and reaches the maximum as the conjugate height is at the optimal altitude. Moreover, the optimal conjugate height changes with the propagation distance.     

Quick single-photon detector with many avalanche photo diodes working on the time division

Due to the limit of response speed of the present single-photon detector, the code rate is still too low to come into practical use for the present quantum key distribution (QKD) system.A new idea is put up to design a quick single-photon detector.This quick single-photon detector is composed of a multi-port optic-fiber splitter and many avalanche photo diodes (APDs).Au of the ports with APDs work on the time division and cooperate with a logic discriminating and deciding unit driven by the clock signal.The operation frequency lies on the number N of ports, and can reach N times of the conventional single-photon detector.The single-photon prompt detection can come true for high repetition-rate pulses.The applying of this detector will largely raise the code rate of the QKD, and boost the commercial use.     

Sorting of bending magnets for the SSRF booster

The Shanghai Synchrotron Radiation Facility(SSRF)booster ring,a full energy injector for the storage ring,is deigned to accelerate the electron beam energy from 150MeV to 3.5GeV that demands high extraction efficiency at the extraction energy with low beam loss rate when electrons are ramping.Closed orbit distortion(COD)caused by bending magnet field uniformity errors which affects the machine performance harmfully could be effectively reduced by bending magnet location sorting.Considering the affections of random errors in measurement,both ideal sorting and realistic sorting are studied based on measured bending magnet field uniformity errors and one reasonable combination of bending magnets which can reduce the horizontal COD by a factor of 5is given as the final installation sequence of the booster bending magnets in this paper.     

Improvement of four-wave mixing-based wavelength conversion efficiency in dispersion shifted fiber by 40-GHz clock pumping

40-GHz clock modulated signal as a pump to improve the efficiency of four-wave mixing (FWM)-based wavelength conversion in a 26.5-km dispersion shifted fiber (DSF) is investigated. The experimental results demonstrate that the conjugated FWM component has higher intensity with the clock pumping than that with the continuous-wave (CW) light pumping. The improvement of FWM-based wavelength conversion efficiency is negligible when the pump power is less than Brillouin threshold. But when the pump power is greater than Brillouin threshold, the improvement becomes significant and increases with the increment of pump power. The improvement can increase up to 9 dB if pump power reaches 17 dBm.     

Characterization of PolyA and PolyC mismatches by Raman spectroscopy

A.C mismatches are studied by Raman spectral characterization of PolyA, PolyC, and their equimolar complex in solution of 0.14 mol/L Na ,pH7.0.Experimental results show that A·C mismatches occur to be A/B (mainly A) conformers, and unlike Watson-Crick base pairing, this kind of mismatches is stabilized by only one hydrogen bond involving cytosine N4H2 and adenine N7.The formation of A·C complex makes the base stacking interactions much stronger, and conformation of the backbone more ordered, which leads to obvious Raman hypochromic effect with some shifts in corresponding bands.