阶梯反射式光纤传感探头

本文从理化和实际上研究了一种阶梯反射式光纤传感探头，用平面和球面端光纤构成探头进行的试验结果表明，这种探头具有良好的光学补偿作用，同时，还有较宽的测量范围，并且其批量制造工艺容易控制，为这种探头的广泛应用奠定了良好的基础。     

反射式光纤温度传感器的研究

在分析了半导体吸收光能原理的基础上提出了一种新型的光纤温度传感器;它以半导体GaAs作为温度敏感元件,采用反射式探头结构,通过光纤传输,实现了测量现场探头和二次仪表的隔离,既避免了带电系统对探头中半导体器件的影响,又避免了测量现场高温工作环境对后续电子器件的影响;通过设置参考通道来减少光源波动以及光纤连接损耗等因素的影响,提高了测量精度;实验证明,在20～140℃的测量范围内精确度可达1℃,可用于电力系统的温度监测.     

光纤荧光矿物油浓度测量中氙灯与光纤的耦合

光纤荧光水中矿物油浓度测量系统以脉冲氙灯作为激发光源,激发光通过光纤束传输到测量探头并激发被测矿物油产生荧光,脉冲氙灯与光纤耦合效率的高低直接影响测量的灵敏度.分析了短弧脉冲氙灯与光纤直接耦合的耦合效率及其影响因素,介绍了FX-1160型脉冲氙灯与石英光纤采用透镜耦合的耦合器的设计.     

反射式光纤位移传感器

论述了反射式光纤位移传感器测量液位的原理，介绍了光纤探头的结构，对其工作原理作了理论性的分析。     

反射式强度补偿光纤角位移传感器研究

提出了一种基于三探头等间距排列结构的反射式光纤角位移传感器,实现具有强度补偿的大量程、高灵敏度角位移测量.理论分析了该传感器的强度补偿角位移测量机理,建立了数学模型得到角度传感调制函数的表达式;仿真分析了光纤探头端面距反射面距离h及探头旋转半径R对传感特性的影响;实验验证了单接收光纤角位移传感特性.结果表明:输出光强和角位移之间呈现较好的线性关系;距离h越大,传感灵敏度越高;R越小,灵敏度越低,但同时传感区间相对越大.     

光纤瞬态电场传感器的研究

为了对高压变电站内因开关操作而产生的空间瞬态电场进行有效的测量,研制了一套光纤瞬态电场传感器.采用球形探头将空间瞬态电场变换为瞬态电压,由置于探头内部的微型光发射机通过光纤把瞬态电压信号传输到远端的光接收机,解决了强电磁干扰环境内的瞬态电场的测量问题.     

Bragg光纤光栅法布里-珀罗应变传感器研究

提出了一种将Bragg光纤光栅(FBG)与全光纤法布里-珀罗传感器(FFPI)结合使用对静态应变进行高分辨率测量的新方法.选用中心波长基本相同的两个光栅组成的光纤法布里-珀罗传感器的反射谱具有光纤光栅和法布里-珀罗干涉仪的共同特性,因此可利用FBG的反射波长与应变漂移特性来粗测应变的范围,利用FFPI和伪外差解调法对精密测量应变的值,实现高分辨率的测量.通过实验测定,该系统对静态应变测量的分辨率达到了59.2nε.     

光纤麦克风的理论和实验研究

一种新型的反射式光纤麦克风,它利用反射式光纤传感探头实现声音对光的外调制.本文从理论和实验两方面研究了反射式光纤麦克风的可行性,并对研制的光纤麦克风系统进行了测试.利用成像原理得出了反射式光纤麦克风的光强度调制函数,根据薄膜振动理论得到了弹性膜片的固有频率和基频,Y型光纤耦合器的使用大大简化了传感器探头的结构.通过实验实现了光纤麦克风系统的预期功能.     

光纤光谱电化学传感器（FOSECS）的研制及应用

作者利用光纤传感器、恒电位电解法及直接电位法的各自特点集为一体,研究了使用方便,便于不同温度下测量,能随时响应电解电压、电极电位及光学信号的FOSECS,并将它用于光谱电化学研究和价态分析,结果均令人满意.1 FOSECS的研制及使用方法FOSECS的结构如图1所示.在工作池和参比池中各固定一大小相等的光纤探头,使探头之敏感膜可据测量对象不同加以更换.使用时向三个池中分别注入饱和KCI溶液,待测     

光纤传输LD推动系统的研究

本文介绍一种用光纤做光通道、激光二极管(LD)做激光源的光功率推动传感器的工作原理,微功耗测量探头的设计方法,脉冲位置调制中应用单根光纤分时双通道解决参考信号的设置,以及光反馈稳定光源等技术.上述措施使传光型光纤传感器的系统稳定性和精度等性能指标得到很大改善.由于被测信号也采用了光纤传输,使探头与仪表端只有光联接,所以本文介绍的光推动传感器可视为“准”全光学式的.     

Call for Papers The 6^th International Conference on Grid and Cooperative Computing

Recent years have seen rapid advances in various grid-related technologies, middleware, and applications. The GCC conference has become one of the largest scientific events worldwide in grid and cooperative computing. The 6th international conference on grid and cooperative computing (GCC2007) Sponsored by China Computer Federation (CCF),Institute of Computing Technology, Chinese Academy of Sciences (ICT) and Xinjiang University ,and in Cooperation with IEEE Computer Soceity ,is to be held from August 16 to 18, 2007 in Urumchi, Xinjiang, China.     

煤矿井下安全监控分站的设计及其仿真实现

为了设计一种具有低成本、低功耗、易操作、功能强且可靠性高的煤矿井下安全分站,针对煤矿安全生产实际,文章提出了采用MCS-51系列单片机为核心、具有CAN总线通信接口的煤矿井下安全监控分站的设计方案;首先给出煤矿井下安全监控分站的整体构架设计,然后着重阐述模拟量输入信号处理系统的设计过程,最后说明单片机最小系统及其键盘、显示、报警、通信等各个组成部分的设计;为验证设计方案的可行性与有效性,使用Proteus软件对设计内容进行仿真验证,设计的煤矿井下安全监控分站具有瓦斯、温度等模拟量参数超标报警功能和电机开停、风门开闭等开关量指示功能;仿真结果表明:设计的煤矿井下安全监控分站具有一定的实际应用价值.     

法律信息库系统

本文分析了法律数据库的结构和特点，介绍了采用面向对象设计方法和超文本数据库技术开发和实现法律信息库系统将作为重要网络资源之一为不同用户进行法律咨询服务。     

View-based model-driven architecture for enhancing maintainability of data access services

In modern service-oriented architectures, database access is done by a special type of services, the so-called data access services (DAS). Though, particularly in data-intensive applications, using and developing DAS are very common today, the link between the DAS and their implementation, e.g. a layer of data access objects (DAOs) encapsulating the database queries, still is not sufficiently elaborated, yet. As a result, as the number of DAS grows, finding the desired DAS for reuse and/or associated documentation can become an impossible task. In this paper we focus on bridging this gap between the DAS and their implementation by presenting a view-based, model-driven data access architecture (VMDA) managing models of the DAS, DAOs and database queries in a queryable manner. Our models support tailored views of different stakeholders and are scalable with all types of DAS implementations. In this paper we show that our view-based and model driven architecture approach can enhance software development productivity and maintainability by improving DAS documentation. Moreover, our VMDA opens a wide range of applications such as evaluating DAS usage for DAS performance optimization. Furthermore, we provide tool support and illustrate the applicability of our VMDA in a large-scale case study. Finally, we quantitatively prove that our approach performs with acceptable response times.     

International Journal of Automation and Computing Table of Contents

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Information for authors

正SCIENCE CHINA Information Sciences(Sci China Inf Sci),cosponsored by the Chinese Academy of Sciences and the National Natural Science Foundation of China,and published by Science China Press,is committed to publishing highquality,original results of both basic and applied research in all areas of information sciences,including computer science and technology;systems science,control science and engineering(published in Issues with odd numbers);information and communication engineering;electronic science and technology(published in Issues with even numbers).Sci China Inf Sci is published monthly in both print and electronic forms.It is indexed by Academic OneFile,Astrophysics Data System(ADS),CSA,Cabells,Current Contents/Engineering,Computing and Technology,DBLP,Digital Mathematics Registry,Earthquake Engineering Abstracts,Engineering Index,Engineered Materials Abstracts,Gale,Google,INSPEC,Journal Citation Reports/Science Edition,Mathematical Reviews,OCLC,ProQuest,SCOPUS,Science Citation Index Expanded,Summon by Serial Solutions,VINITI,Zentralblatt MATH.     

Erratum to: Fast global kernel fuzzy c-means clustering algorithm for consonant/vowel segmentation of speech signal

正Erratum to:J Zhejiang Univ-Sci C(ComputElectron)2014 15(7):551-563doi:10.1631/jzus.C1300320The original version of this article unfortunately contained mistakes.Algorithm 6 should be as follows:Algorithm 6 FGKFCM-F clustering Input:(1)X={x_1,x_2,…,x_N},,x_iR~d,i=1,2,…,N,the dataset;(2)C,1C≤N,the number of clusters;(3)ε0,the stopping criterion;     

Journal of Zhejiang University-SCIENCE C (Computers & Electronics) Total contents

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A pragmatic multi-method investigation of discrepant technological events: Coping,attributions, and ‘accidental’ learning

Discrepant technological events or situations that entail a problem, a misunderstanding or a difficulty with the Information Technology (IT) being employed, are common in the workplace, and can lead to frustration and avoidance behaviors. Little is known, however, about how individuals cope with these events. This paper examines these events by using a multi-method pragmatic approach informed by coping theory. The results of two studies – a critical incident study and an experiment – serve to build and test, respectively, a theoretical model that posits that individuals use a variety of strategies when dealing with these events: they experience negative emotions, make external attributions, and adopt engagement coping strategies directed at solving the event, eventually switching to a disengagement coping strategy when they feel they have no control over the situation. Furthermore, users’ efforts may result in ‘accidental’ learning as they try to overcome the discrepant IT events through engagement coping. The paper ends with a discussion of the results in light of existing literature, future opportunities for research, and implications for practice.