基于FPGA的红外图像仿真注入系统

设计了一种新的图像注入系统来实现PC机仿真图像到红外处理系统的直接传输。首先,该系统利用USB2.0接收PC机对外场实测数据仿真得到的BMP格式文件,用FPGA控制由两个SDRAM组成的缓冲模块进行图像缓存,然后通过Camera Link接口传送出去。系统数据缓存采用乒乓操作,避免了数据处理时无法持续接收而丢失有效数据的现象。测试时用图像采集卡进行图像采集并显示。结果表明,该系统具有速度快、实时性好、稳定性高等特点,可替代光电跟瞄设备进行仿真训练及设备的动态检验。     

基于FPGA的红外图像仿真注入系统

设计了一种新的图像注入系统来实现PC机仿真图像到红外处理系统的直接传输。首先,该系统利用USB2.0接收PC机对外场实测数据仿真得到的BMP格式文件,用FPGA控制由两个SDRAM组成的缓冲模块进行图像缓存,然后通过Camera Link接口传送出去。系统数据缓存采用乒乓操作,避免了数据处理时无法持续接收而丢失有效数据的现象。测试时用图像采集卡进行图像采集并显示。结果表明,该系统具有速度快、实时性好、稳定性高等特点,可替代光电跟瞄设备进行仿真训练及设备的动态检验。     

基于单片机的霍尔效应实验数据采集和显示系统的研发

介绍了一种基于单片机的数据采集、传输和显示系统,该系统是以大学物理实验中的霍尔效应测磁场实验为基础,阐述了其结构、功能、硬件及软件的设计过程。本系统采用单片机通过R232协议和PC机进行通信,通过A/D转换模块、STC89C52RC单片机主控模块、串口通信、数据处理和显示等模块来实现一种高效的数据采集、传输和显示,该系统在实验教学中具有一定的应用前景和商业价值。     

基于ZigBee的矿井环境监测系统设计

针对矿井环境恶劣、干扰严重和传统信号有线传输的现状,设计了基于ZigBee无线传感器网络的矿井环境监测系统;系统由井下ZigBee传感器终端节点、路由器、协调器和井上监测上位机构成,其中传感器终端节点对井下瓦斯、一氧化碳、温度等信号进行采集,利用ZigBee无线组网技术将信号送给井上PC机,井上管理人员通过PC机能够随时掌握井下设备和环境的状况;与传统的信号有线传输监测方法相比,该系统低功耗、低成本、抗干扰;实验结果表明,该系统运行稳定可靠,精度高,具有一定的实用性和推广价值。     

蓝牙技术在大型镜面能动磨盘加工中的应用研究

利用蓝牙无线通信方式解决大型光学镜面加工中对能动磨盘的控制。该方法利用单片机控制蓝牙模块，采用基于HCI层的单片机对蓝牙模块控制的方法及PC机端通过RS232接口连接蓝牙模块互相配合，实现PC机与能动磨盘之间的通信。单片机根据蓝牙HCI层协议对蓝牙接收和发送数据进行处理。在蓝牙传输协议的基础上给出了应用于镜面能动磨盘加工中的软硬件实现方案。该技术克服了现在使用导电环带来的易磨损、成本高的缺点，对降低加工成本，减少复杂的工业布线有很大的意义。可以替代其他镜面加工中的导电环来进行控制数据传输，也可应用在其他无线串行通信领域。     

一种便携式多生理参数采集系统的设计

本文设计了一种便携式多生理参数采集系统。该系统可以实现对人体呼吸、指脉、动作、皮电、血压、心电等六个体征参数的采集;该系统利用串口转USB传输可以实现采集到的人体生理参数与PC间的相互传输,测量结果和分析报告可以在PC 机进行实时显示和存储或者可以通过Internet向远程医疗服务中心进行数据的上传、备份、分析与反馈。所以,利用该系统可以实现对人体体征参数实时、连续的采集与监测。     

BEPCⅡ束流损失探测系统及其初步应用

束流寿命是衡量储存环性能的重要参数,它直接影响到储存环能否正常运行.采用束流损失探测系统通过探测束流损失的地点,可以为分析束损原因、优化机器参数和提高束流寿命提供依据.介绍了北京正负电子对撞机重大改造工程(BEPC Ⅱ)束流损失探测系统的基本情况:前端束流损失探测器输出的脉冲信号送到下位机进行处理,通过CAN总线将所有的下位机连接到位于本地站的前端PC机,此PC机再通过以太网与中控室的PC机或工作站进行数据通讯,最终实现对束流损失的实时监测、数据存储,并能对历史数据进行处理,达到实时显示全环束损分布的目的.文章最后还简要介绍了整个系统在BEPC Ⅱ调束过程中的初步应用.     

基于GPRS的下水道气体远程监测系统设计

为了提高城市下水道气体监测的实时性和可靠性,本文设计了基于GPRS的下水道气体远程监测系统。该系统主要包括前端气体采集模块、GPRS数据无线传输模块、数据接收模块及监控中心;气体采集模块由气体传感器和数据采集单片机组成;单片机实时采集气体传感器中的数据,并将采集到的数据通过GPRS无线传输模块进行实时上传;数据接收模块把接收到的数据传送至监控中心服务器,由服务器对数据进行处理、显示、存储和统计等。通过对18个监测点的监测实验效果表明,该系统运行稳定可靠,能实现对下水道气体远程采集、无线传输和实时监测的目的。     

BEPCⅡ束流损失探测系统及其初步应用

束流寿命是衡量储存环性能的重要参数, 它直接影响到储存环能否正常运行. 采用束流损失探测系统通过探测束流损失的地点, 可以为分析束损原因、优化机器参数和提高束流寿命提供依据. 介绍了北京正负电子对撞机重大改造工程(BEPCⅡ)束流损失探测系统的基本情况: 前端束流损失探测器输出的脉冲信号送到下位机进行处理, 通过CAN总线将所有的下位机连接到位于本地站的前端PC机, 此PC机再通过以太网与中控室的PC机或工作站进行数据通讯, 最终实现对束流损失的实时监测、数据存储, 并能对历史数据进行处理, 达到实时显示全环束损分布的目的. 文章最后还简要介绍了整个系统在BEPCⅡ调束过程中的初步应用.     

新型生物医药实验用低温冷冻干燥机的研制

本课题设计的低温冷冻干燥机以液氮为低温冷源,通过电加热器加热液氮使之汽化,通过控制气体的压力,压出液氮。液氮被压出后流入硅油池的换热器同硅油进行充分换热。在硅油池底部布置一个电加热盘,通过调节加热量,精确控制硅油温度。特制的不锈钢搁板浸入硅油池中进行硅油浴,能够实现良好的传热。测控制系统由上位PC机与下位可编程控制器和数据采集模块共同组成,在PC机上可设置控制参数并进行监控,温度曲线可程序控制,数据采集模块能够自动采集、存储、上传各项数据,数据可以在PC机上处理。     

Self-organization of five species in a cyclic competition game

Cyclic competition game models, particularly the “rock–paper–scissors” model, play important roles in exploring the problem of multi-species coexistence in spatially ecological systems. We propose an extended “rock–paper–scissors” game to model cyclic interactions among five species, and find that two of the five can coexistent when biodiversity disappears, which is different from the “rock–paper–scissors” game. As the number of fingers is five, we named the new model the “fingers” game, where the thumb, forefinger, middle finger, ring finger, and little finger cyclically dominate their subsequent species and are dominated by their former species. We investigate the “fingers” model in two ways: direct simulations and nonlinear partial differential equations. An important finding is that the number of species in a cyclic competition game has an influence on the emergence of biodiversity. To be specific, the “rock–paper–scissors” model is in favor of maintaining biodiversity in comparison with the “fingers” model when the variables (population size, reproduction rate, selection rate, and migration rate) are the same. It is also shown that the mobility and reproduction rate can promote or jeopardize biodiversity.     

Contrastive analysis on tone between Putonghua and Taiwan Mandarin

The differences of the pitch and duration of Chinese syllables between Putonghua （PTH） and Taiwan Mandarin （TM） were studied. The speech materials to be used are not only isolated syllables, but also sentences. The results reveal that： For the isolated syllables, T1 and T2 in TM are influenced by Minnan dialect, therefore their pitch are lower than those in PTH. T3 is fall-rise in PTH, while it is fall in TM. Moreover, the syllable duration sequence for different tone is T3〉T2〉T1〉T4 in PTH, while it is T1〉T2〉T3〉T4 in TM. For the syllables in sentences, T2 is mid-rise in PTH, while it is mid-level in TM. And the T3 is longer than T4 but shorter than T1 or T2 in PTH, while it is the shortest in TM. Furthermore the effects of prosodic phrase boundary on duration for different tones are almost the same in PTH, but the lengthening part of T1 or T2 is longer than that of T3 or T4 in TM.     

Experimental study on downstep in Chinese intonation

Downstep in pitch contour of Chinese Putonghua is examined using subtly designed sentences by controlling tone combinations. The results show both automatic and nonautomatic downstep phenomena exist in Chinese. In non-automatic downstep, low tones compress downwards the pitch range of the following syllables. and the main influence of downstep is on topline. Low tone not only lower the topline behind it, but also raise the high tones before it, the effects are compatible with each other. In automatic downstep, the topline of pitch contour in intonational phrase is presented as a linear downtrend, but it differs among speakers due to the effect of personal stress practice. In comparison with downstep phenomenon in other tone or non-tone languages, the downstep ratio in Chinese is not constant, and the domain of downstep is not limited within the adjacent tones.     

Abelian-Higgs phase of SU(2) QCD and glueball energy

It is shown that SU(2) QCD admits an dual Abelian-Higgs phase, with a Higgs vacuum of a type-Ⅱ superconductor. This is done by using a connection decomposition for the gluon field and the random-direction approximation. Using a bag picture with soft wall, we presented a calculational procedure for the glueball energy based on the recent proof for wall-vortices [Nucl. Phys. B 741(2006)1].     

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.     

Signal generation in an isotropic medium in scanning electron acoustic microscope

Based on the research in Ref. [5][Materials Science and Engineering, 1989; A122： 57 63], an improved model of heat source is set up, the different modes of Lamb wave in an isotropic sample generated by a chopped electron beam at frequency f are obtained with integral transform and normal function expansion method, and the output signal of PZT coupled at the back surface of the sample is found out. The generation mechanism of SEAM （Scanning Electron Acoustic Microscopy） signal is discussed. It shows that the SEAM is a near field imaging technique with high spatial resolution and its best lateral spatial resolution is about 2√2α （α is the radius of the focused electron beam）. Some of experimental results of SEAM images are presented in the paper and it shows that the spatial resolution of SEAM is better than 0.5 μm and smaller than the thermal diffusion length of the sample. Therefore the character of near field imaging in SEAM is also proved experimentally.     

High efficiency filtering using two-dimensional photonic crystal coupled cavity structures

Transmission spectra of coupled cavity structures (CCSs) in two-dimensional (2D) photonic crystals (PCs) are investigated using a coupled mode theory, and an optical filter based on CCS is proposed. The performance of the filter is investigated using finite-difference time-domain (FDTD) method, and the results show that within a very short coupling distance of about 3λ, where λ is the wavelength of signal in vacuum, the incident signals with different frequencies are separated into different channels with a contrast ratio of 20 dB. The advantages of this kind of filter are small size and easily tunable operation frequencies.