基于单片机的炭黑复合导电材料的电阻-温度测量系统

以AT89S51单片机为核心,采用热电偶放大器芯片AD595,设计炭黑复合导电材料的电阻-温度测试系统,实现了电阻和温度的测量.介绍系统的硬件结构和软件设计方法,特别是温度和电阻的采集和显示过程.实验结果表明,设计的系统能够方便准确地测量电阻和温度的变化,测量数据验证了炭黑复合导电材料的PTC特性.     

基于低温冷冻治疗仪的温度测量方法

采用热电偶信号放大器AD595结合K型热电偶温度传感器,设计基于低温冷冻治疗仪的热电偶测温电路;实现了冷端自动补偿、温度曲线升降功能;测量电路结构简单、成本较低,具有较强的实用性。     

新型温度采集系统的设计与实现

温度测量在工业生产和科学研究中应用较广,并且通常需要同时测量多路温度信号。AD595是K型热电偶专用芯片,具有低阻抗电压、冷端补偿、断线报警的特点。AD595结合多路选择开关和USB数据采集卡,上位机软件利用图形化编程语言Labview编制,可以实现多路温度传感器信号的实时显示及存储。     

4款低成本精密热电偶放大器

热电偶系统可提供精确而可靠的温度测量和控制功能,经济有效,并且温度测量范围较宽。然而,为了实现良好的测量性能,冷结补偿和高增益精度精密放大器是必不可少的。ADI公司的热电偶放大器AD8494、AD8495、AD8496和AD8497专门针对此问题而开发,具有片内冷结补偿功能,可根据环境温度的变化自动调整热电偶输出。相对于类似的分立解决方案。此特性可大大简化设计过程并降低系统成本。     

基于AD8302芯片的新的幅相测量系统

介绍了利用美国AD I公司AD8302芯片测量RF/IF幅度和相位差的一种幅相测量系统。由于该芯片将精密匹配的两个对数检波器集成在一块芯片上,因而可将误差源及相关温度漂移减小到最低限度,可用于GSM(全球移动通信系统)、电力系统的阻波器、结合滤波器等领域。给出了该芯片的工作原理、模式及典型应用;介绍了该芯片在电力阻波器测试仪中的应用以及测量幅度、相位差、阻抗计算的方法。     

太阳能发电机控制系统的温度采集电路设计

介绍了一种基于AD7606多路K型热电偶温度采集电路的设计,采用斯特林太阳能发电控制系统,运用热电偶与AD转换芯片AD7606组成温度采集电路,将采集好的数据经单片机进行数据处理后传送给上位机。实验结果表明,文中设计功能稳定、精度高,分辨率高的温度测量要求,达到了技术指标。     

AD8295：仪表放大器

ADI推出高集成度的精密仪表放大器前端AD8295，适合工业与仪器仪表应用。在单个4×4mm芯片级封装内，AD8295仪表放大器集成了一个顶级仪表放大器、两个可配置的运算放大器和两个精密微调匹配电阻，可为工业过程控制、精密数据采集系统、医疗仪器仪表设备及惠斯登电桥测量等应用提供集成前端。     

ADI公司的放大器节省电路板空间并降低设计复杂性，适合工业与仪器仪表设备

Analog Devices，Inc．最新推出高集成度的精密仪表放大器前端——AD8295，与同类放大器解决方案相比，仪占用50％的电路板空间，适合工业与仪器仪表应用。在单个4mm×4mm芯片级封装内，AD8295仪表放大器集成了一个顶级仪表放大器、两个可配置的运算放大器和两个精密微调匹配电阻，可为工业过程控制、精密数据采集系统、医疗仪器仪表设备及惠斯登电桥测量等应用提供集成前端。     

大动态范围水声声压信号监测系统设计

采用软件可编程增益放大器和单片机控制实现了水声声压信号的数字式测量与监控。利用两级可编程增益放大器AD526芯片级联的方法实现宽动态范围电压信号的量程调整。通过单片机反馈控制系统调整前级放大器的倍数．使电压真有效值测量芯片AD536A工作于最优工作区间。根据当前A／D转换芯片的采样值和前级放大倍数进行运算以实现对声压信号的测量。实验结果表明：该系统电压测量动态范围可以达到68dB,频率响应范围为0-100kHz,能够满足水声信号的测量要求。     

热电偶冷端补偿器LT1025及其应用

简要介绍了凌特公司生产的微功耗热电偶冷端补偿芯片LT1025的原理及其应用。在温度测量时．该芯片可用于对各种热电偶的冷端进行温度补偿，且在较广泛的温度范围内具有较高的补偿精度。     

Resolution Enhancement Technology:Integrated Process Solutions using OPC

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.     

Cost-effective test solutions for smart card and other integrated flash applications

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.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

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.     

An improved parallel thinning algorithm with two subiterations

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.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

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.     

Development of the readout system for waveguide multilayer optical card

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.     

Study of waveguide coupling efficiency in hybrid silicon lasers

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.     

Collinear phase-matching study of terahertz-wave generation via difference frequency mixed in GaAs and Inp

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.     

Effects of the alloy compositions on the phonon-polaritons in ternary mixed crystals

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.     

New insert layer structure OLEDs

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.