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针对传统的电能质量分析仪以硬件为核心,功能单一、成本高、数据处理慢等问题,该文采用软硬件相结合,借助于数据采集卡以LabVIEW软件为开发平台研发了风电场电能质量监测系统,通过数据采集卡采集风电场的三相交流信号,并对电压偏差、频率偏差、谐波、三相不平衡、电压波动等指标进行监测并分析给出风电场运行状态和风电场对电网的影响。系统实现了长期自动运行,实时测量分析、存储数据的功能,开发周期短,具有良好的可视化人机交互界面,便于修改系统的功能和规模,为用户提供了高度的灵活性和易用性。 相似文献
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表面肌电信号是肌肉收缩的同时伴随的一种电压信号,是一种复杂的表皮下肌电信号活动在皮肤表面处的时间和空间上综合得出的结果,能够反映出神经、肌肉的功能状态。正是其在相同肌群规律性和在不同肌群差异性,使得利用肌电信号作为人机接口来控制上肢康复机器人成为可能。本文的主要内容是肌电信号采集系统的设计,将从硬件电路以及软件设计两部分进行阐述。其中硬件电路主要由表面电极、信号调理、NI-USB-6210数据采集卡和上位机四部分组成;系统软件采用虚拟仪器开发平台LabVIEW编程,完成肌电信号实时采集、滤波处理、数据存储等功能。 相似文献
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介绍一种基于虚拟仪器LabVIEW的心电信号检测处理系统,阐明了虚拟仪器的基本概念及其在医学测量系统的应用,具体给出了心电信号放大、隔离电路的设计方案,借助数据采集DAQ卡PCI6070E实现对心电信号进行采集,通过图形化语言的编程对采集的心电数据进行分析、存储、共享。该系统可实现心电生理信号实时采集显示、心电信号HRV分析等功能,构造一套比较实用的心电虚拟仪器,对虚拟仪器在医学生物信号处理和医疗仪器开发方面有一定的参考价值。 相似文献
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在简要介绍心电信号数据采集系统的基础上,重点论述了12位逐次逼近式模/数转换芯片AD574的特性、工作原理及其在心电数据采集系统中的具体应用。详细地给出了AT89S51单片机与AD574的连接方案以及存储AD574处理结果的接口电路。利用12位并行的AD574芯片实现了高速、高精度的心电信号的A/D转换功能,电路通用性强,具有很好的实际应用参考价值。 相似文献
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变压器绕组匝间故障检测对于保证电力系统稳定运行有重要意义,由于变压器自身很容易遭受外界冲击,进而出现故障,为此应用负序电信号设计了一种新的变压器绕组匝间故障检测系统。在硬件上分别设计了故障信号转化模块和数据检测模块,选用HIEC APF滤波器作为数据采集装置,选择208系列变送器检测故障数据。软件部分利用负序电信号针对三相系统的特点对向量图进行数据处理,将三相数据相加,并分类不同的电力结构,针对电力系统内部故障进行数据检测操作,实现变压器内部故障检测。实验结果表明,设计系统具备很好地确定分布式参数分布状态的能力,当频率超过0.3 kHz时出现对称,表明变压器存在短路故障,故障越严重,变压器绕组匝间阻抗值和相关系数的变化越大。 相似文献
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以非接触式的电机转速测量方法为核心,基于虚拟仪器和LabVIEW设计了一种感应电机测试系统.该系统实现了同步、实时监测电机的转速、三相电压和三相电流等多路信号,并对采得的信号可实现实时存储、动态回放和分析处理以及图形打印等功能.通过部分试验测试表明了系统的功能和特点. 相似文献
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脑电能反映人脑的健康及认知活动状况,是脑疾病诊治及认知神经科学的重要参数。基于头皮脑电的脑电信号监测也是脑机接口的重要手段。该文开发一种基于柔性石墨烯干式脑电(EEG)电极和便携式无线终端的脑电采集系统。利用真空抽滤的方法制备了柔性聚酯纤维(织物)基底石墨烯织物电极,基于ADS1299模拟前端和超低功耗单片机设计实现了便携式低功耗无线脑电采集系统,能够实现脑电信号的采集、处理、存储和无线传输。对石墨烯电极的导电特性、耐久性、稳定性进行了测试并和商用氯化银电极进行了对比。结果表明,文中开发的石墨烯电极能够实现脑电信号的高信噪比精确采集,并且满足长期佩戴所需的耐摩擦性。与皮肤连续摩擦接触的测试结果表明,随着时间的推移,石墨烯电极本征阻抗及采集的脑电信号质量并没有发生明显变化。基于石墨烯电极的便携式无线脑电采集系统数据采集准确可靠,设计合理,运行稳定,能够满足便携式脑电采集设备的需要。 相似文献
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数据采集系统是海底原位监测系统的核心。为了实现对海底边界层进行微剖面数据采集,系统以ARM9为控制核心,MSP430为电源控制模块核心,基于Linux软件平台,集成了9台深海设备,采用双ARM冗余控制与数据存储设计。系统通过步进电机控制传感器框架在三个不同高度工作,从而实现了实时、自动化、稳定的微剖面数据采集与控制管理功能。 相似文献
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Michael Reilly 《半导体技术》2004,29(12)
DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system. 相似文献
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Thomas M.Trexler 《半导体技术》2004,29(5)
From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test. 相似文献
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The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation. 相似文献
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The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high. 相似文献
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Today, micro-system technology and the development of new MEMS (Micro-Electro-Mechanical Systems) are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible. 相似文献
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GU Min-fen LIANG Zhong-cheng WANG Ren-zhou DONG Xiang-mei ZHANG Pei-ming CHEN Jia-bi 《光电子快报》2008,4(2):150-152
Waveguide multilayer optical card (WMOC) is a novel storage device of three-dimensional optical information. An advanced readout system fitting for the WMOC is introduced in this paper. The hardware mainly consists of the light source for reading, WMOC, motorized stages addressing unit, microscope imaging unit, CCD detecting unit and PC controlling & processing unit. The movement of the precision motorized stage is controlled by the computer through Visual Basic (VB) language in software. A control panel is also designed to get the layer address and the page address through which the position of the motorized stages can be changed. The WMOC readout system is easy to manage and the readout result is directly displayed on computer monitor. 相似文献
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Qi-jiang Ran Pei-de Han Yu-jun Quan Li-peng Gao Fan-ping Zeng Chun-hua Zhao 《光电子快报》2008,4(4):239-242
This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel's. 相似文献
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The collinearly phase-matching condition of terahertz-wave generation via difference frequency mixed in GaAs and InP is theoretically studied. In collinear phase-matching, the optimum phase-matching wave hands of these two crystals are calculated. The optimum phase-matching wave bands in GaAs and lnP are 0.95-1.38μm and 0.7-0.96μm respectively. The influence of the wavelength choice of the pump wave on the coherent length in THz-wave tuning is also discussed. The influence of the temperature alteration on the phase-matching and the temperature tuning properties in GaAs crystal are calculated and analyzed. It can serve for the following experiments as a theoretical evidence and a reference as well. 相似文献
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Composition dependence of bulk and surface phonon-polaritons in ternary mixed crystals are studied in the framework of the modified random-element-isodisplacement model and the Bom-Huang approximation. The numerical results for Several Ⅱ - Ⅵ and Ⅲ- Ⅴ compound systems are performed, and the polariton frequencies as functions of the compositions for ternary mixed crystals AlxGa1-xAs, GaPxAS1-x, ZnSxSe1-x, GaAsxSb1-x, GaxIn1-xP, and ZnxCd1-xS as examples are given and discussed. The results show that the dependence of the energies of two branches of bulk phonon-polaritons which have phonon-like characteristics, and surface phonon-polaritons on the compositions of ternary mixed crystals are nonlinear and different from those of the corresponding binary systems. 相似文献
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An insert layer structure organic electroluminescent device(OLED) based on a new luminescent material (Zn(salen)) is fabricated. The configuration of the device is ITO/CuPc/NPD/Zn(salen)/Liq/LiF/A1/CuPc/NPD/Zn(salen)/Liq/LiF/A1. Effective insert electrode layers comprising LiF(1nm)/Al(5 nm) are used as a single semitransparent mirror, and bilayer cathode LiF(1 nm)/A1(100 nm) is used as a reflecting mirror. The two mirrors form a Fabry-Perot microcavity and two emissive units. The maximum brightness and luminous efficiency reach 674 cd/m^2 and 2.652 cd/A, respectively, which are 2.1 and 3.7 times higher than the conventional device, respectively. The superior brightness and luminous efficiency over conventional single-unit devices are attributed to microcavity effect. 相似文献