分布式光纤测温系统在石油测井中的应用

重点论述了观察井测温在油田开采中的重要性和所面临的问题,介绍了分布式光纤温度传感(DTS)技术原理以及在油田温度监测中的应用.最后展望了光纤分布式测温传感器在油田测试中的应用前景.     

基于光频域反射技术的光纤传感网络研究

研究基于光频域反射技术的光纤传感网络,提升待监测对象温度与应变的测量精度。在光频域反射技术基础上引入光纤Bragg光栅技术,构建具有分立式与分布式的两层混合式光纤传感网络;分立式光纤传感网络层利用光纤Bragg光栅技术解调光栅放射光中心波长变化量,获取待监测对象温度值;分布式光纤传感网络层通过计算光纤瑞利散射的光谱平移量实现应变的连续分布式传感,利用频域干涉测量法,计算光纤传感器中心波长变化量,获取待监测对象应变值。同时两层混合式光纤传感网络利用傅立叶插值后的互相关法提高光谱平移量的光谱分辨率,提升光纤传感网络的测量精度。实验证明:所研究光纤传感网络测量的中心波长值与实际温度值、应变值拟合程度高,测量精度高。     

基于主动加热方法的隧道积水分布式光纤传感器

针对目前隧道积水事件及积水范围监测需求,研发了两种新型隧道积水传感器,提出了基于分布式温度传感(DTS)的隧道积水分布式感测方法。通过将传感光缆按二维平面螺旋封装方式提高了传感器的空间分辨率,利用主动加热方法,显著提高了水-气界面传感光缆的温度差异,进而实现对积水事件和积水范围的识别。通过室内模型试验,对传感光缆的性能及影响因素进行了研究。结果表明,研发的两种传感器均具有较高的空间分辨率,由于螺旋Ⅰ型的环间距更小,其空间分辨率及定位精度均高于螺旋Ⅱ型;在多种典型工况下两种传感器均可以准确识别积水的水-气界面,定位误差均小于10 cm;适当增大加热温度可以提高传感器的定位精度,50℃加热工况时的定位精度明显优于35℃和20℃。     

分布式Raman测温系统在隧道中的应用

由于隧道半密闭的结构特殊性,有火情发生时高温和浓烟会对隧道设施和人身安全造成极大的伤害,因此监测隧道温度的分布特点对于火灾预防和及时扑灭具有重要意义。分布式温度监控系统由DTS下位机、多模传感光纤和温度解调上位机软件组成。文中介绍了分布式温度监控系统的工作原理与系统结构,说明了斯托克斯(Stokes)光和反斯托克斯(Anti-Stokes)光强的温度解调方式,将分布式Raman测温系统应用于隧道测温,通过搭建分布式温度监控系统解调得到整个隧道准确的实时温度变化情况,给出了昆玉高速山心坡隧道现场实测数据。从实际温度曲线可以看出,解调出来的温度与实际温度相差基本一致,可以应用于隧道测温现场,对隧道温度进行实时监测。     

分布式光纤传感器开关柜温度监测探讨

阐述了分布式光纤温度传感器的工作原理,根据电力设备温度监测的特点,探讨了用于高压开关柜温度在线监测的传感系统方案。设计了基于全分布式和准分布式光纤传感技术的高压开关柜温度监测系统,比较了不同监测系统的特点,指出了适用于电力系统高压开关柜温度测量的方法。     

基于光纤传感技术在边坡监测中的应用研究

FBG和BOTDR是两种最具代表性的分布式光纤传感技术,国内外工程界都已开展了将这两种技术用于边坡滑坡监测的尝试。FBG通过测量其反射光波长的变化获得应变和温度信息,BOTDR通过检测后向布里渊散射的频移实现分布式应变、温度信息的获取。分别介绍了FBG和BOTDR传感技术,并给出了针对国内某边坡滑坡监测的分别基于FBG和BOTDR的技术方案。     

基于物联网技术的广播电视高空天馈线温湿度监测解决方案

通过对物联网的无线传感等技术的研究,提出利用RFID无线传感设备对广播电视行业高空天馈线温度进行监测的解决方案,简化了传统的高空监测布线施工的困难,提高监测效果。     

煤矿井壁冻结温度场监测系统

根据分布式光纤温度监测系统的工作原理,分析其应用于冻结壁温度场监测的可行性,对冻结壁温度场监测系统的组成、监测数据的处理和光缆布设方案进行研究,设计的分布式光纤煤矿井壁冻结温度场监测系统实现了0.5m的连续测温空间分辨率,温度分辨率为0.1℃,并应用于冻结壁温度场的温度监测.与传统的单总线温度传感测温系统的测温数据对比,其具有测量温度值准确、数据量大、系统稳定性高和布设更加方便等优点.     

基于脉冲激光器的电动汽车锂电池温度在线监测

为提高锂电池温度在线监测能力，通过双路解调方案构建分布式拉曼光纤温度测试系统，采用外部触发方式，实现相互协调的工作状态。温度测试结果表明，常温状态下系统各通道距离10 m范围的温度精度达到±1℃。经过8次测试后温度值误差均在0.17℃内，表明系统常温条件下可以保持良好的稳定性，满足设计条件。该系统能够满足锂电池的测温要求，能够对锂电池局部温度异常情况进行准确反馈，有效预防锂电池各类事故。10 m传感距离内行程误差最大值只有2 m,符合锂电池测温要求。模拟试验测试结果表明，该系统能够对故障进行准确辨别与定位，表明系统具备优异的分布式测试性能。DTS系统可以达到±1 m的分辨能力，可以快速响应锂电池故障引起的温度变化。     

基于FBG和光频域反射技术的混合式光纤传感网研究

基于光纤Bragg光栅技术和光频域反射(OFDR)技术 ,构建了一个具有分立式传感子层和分布式传感器子层的双层结构混合式光纤传感网络。 在分立式传感子层中,FBG用于实现温度参量的传感;在分 布式传感子层中,采用OFDR方法解调光纤中的瑞利散射信息从而获得分布式的应 变参量。整个传感 网络共用同一个宽光谱可调谐激光光源,分立式子层和分布式子层两者协同工作,实现应变 和温度两个参 量的高精度测量,其中应变分辨率达到0.75με,温度分辨率达到 ±1℃。本文构建的传感网络为构建大容量、 大规模、多参量、高空间分辨率和高测量精度的光纤传感网络提供了一种有益探索。     

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.     

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.     

Teleportation of an arbitrary unknown N-qubit entangled state under the controlling of M controllers

A new quantum protocol to teleport an arbitrary unknown N-qubit entangled state from a sender to a fixed receiver under M controllers(M < N) is proposed. The quantum resources required are M non-maximally entangled Greenberger-Home-Zeilinger (GHZ) state and N-M non-maximally entangled Einstein-Podolsky-Rosen (EPR) pairs. The sender performs N generalized Bell-state measurements on the 2N particles. Controllers take M single-particle measurement along x-axis, and the receiver needs to introduce one auxiliary two-level particle to extract quantum information probabilistically with the fidelity unit if controllers cooperate with it.     

Diode-end-pumped Nd:YVO4/LBO lasers with 4.2W continuous-wave output at 457 nm

A continuous-wave (CW) 457 nm blue laser operating at the power of 4.2 W is demonstrated by using a fiber coupled laser diode module pumped Nd: YVO4 and using LBO as the intra-cavity SHG crystal With the optimization of laser cavity and crystal parameters, the laser operates at a very high efficiency. When the pumping power is about 31 W, the output at 457nm reaches 4.2 W, and the optical to optical conversion efficiency is about 13.5% accordingly. The stability of the out putpower is better than 1.2% for 8 h continuously working.     

Call for Papers

正Wireless Body-area Networks The last decade has witnessed the convergence of three giant worlds:electronics,computer science and telecommunications.The next decade should follow this convergence in most of our activities with the generalization of sensor networks.In particular with the progress in medicine,people live longer and the aging of population will push the development of wireless personal networks     

Call for Papers—Feature Topic,Vol.12,No.7,2015

正Information Centric Networking Information-Centric Networking(ICN) is an emerging direction in Future Internet architecture research,gaining significant tractions among academia and industry.Aiming to replace the conventional host-to-host communication model by a data-centric model,ICN treats data content as the first