智能水质连续监测传感器网络系统

本文介绍了一种智能水质连续监测系统。通过先进的监测传感器,实时监测水质的各项参数,将数据通过网络上传至数据中心。本文的目标是构建一个系统,可以连续监测长距离河流水质参数的变化,能够克服现有方法的局限性,代替人力监测。该系统的主要内容包括系统设计和传感器模块。其中,系统设计包括系统功能分析、系统功能模块设计、接口和信息处理以及网络设计等,传感器模块包括光纤光栅传感器应用和传感器的接口设计。     

IHSMS-I型测量控制单元(MCU)功能及特点

IHSMS-I型测量控制单元可以根据工程需要组成总线网、星型网、环型网，或者混合型网络，可以通过有线、光线、无线组建通信网络1．智能化IHSMS-I型测量控制单元（MCU）是一通用测量系统。系统可根据不同现场环境和监测要求，通过操作面板或计算机现场或远程设置、修改传感器通道参数；     

基于无线传感器技术的水文监测系统设计

针对水文信息监测区域广、监测参数多以及传统水文监测系统所存在的问题,依据监测点的特点,利用ZigBee和GPRS技术,开发了基于无线传感器技术的水文监测系统,实现了水文参数的无线传输。ZigBee技术具有自组网、成本低、耗能少等特点,可以很好地解决水文监测系统设计中存在的问题。系统可将传感器采集到的温度、pH值和水位等参数通过ZigBee网络无线传输到监测中心,再通过GPRS模块的短信通信功能将报警信息发送至用户手机上,使相关人员实时掌握水情情况     

智能数据采集系统(IDAS)简介

IDA系统是Sinco公司近年来投入市场的新产品。IDA是智能数据采集的缩写。 该系统的主要器件有:传感器、多路模块,接口重发器、终端箱、I/R模块、电源、个人计算机、传感电缆、总线、各种雷击保护器、总线电源控制器、过压保护器、人工读数适配器及便携式读数显示器等。 多路模块把传感信号转换成数字形式并通过IDA总线将其传输到现场的个人计算机中。PC机将转换从工程单位中获得的数据并将其存入软盘。如果需要,PC机也可以分析比较输入数据来预置报警界限和发出警报。数据能打印、显示并能多次不断的从前置PC机反回到后置PC机。 前置PC机用于数据记录而后置机则用于数据分析,数据由调制解调器或软磁盘传输。 后置PC机负责数据库的数据归档,数据分析、绘图和生成报表。 美国田纳西州工程管理局(TVA)在方泰娜坝的监测中采用了IDAS,该系统运行良好,亦可用于滑坡和尾矿坝的监测。     

水电站水位测量系统中的无线传感技术研究与应用

本文提出了一种基于ZIGBEE无线传感技术的水位测量系统方案。首先给出了测量系统的系统构架和功能分析;其次,针对传感器节点和协调器节点进行了硬件方案设计;最后,详细介绍了网络节点中LPC2210与MC13192模块之间SPI通信流程和详细的软件实现过程。     

基于PC机的水电机组振动监测系统的开发

针对水电机组运行过程中因振动而引起故障这一问题，开发出了一种基于PC机的新型水电机组振动在线监测分析系统。该系统由PC机、专用数据采集箱、摆度、振动传感器及有关功能模块共同组成。重点讨论了系统的数据实时监测模块、振动分析模块、历史数据管理模块的问题，该系统能够连续地在线监测机组振动和摆度的变化过程，可以为机组检修及运行调度提供良好的依据和可靠的信息。     

GNSS变形监测预警系统在龙江水电站中的应用

为保障龙江水电站工程安全运行,引进GNSS技术对大坝及边坡进行实时变形监测。GNSS变形监测系统主要包括GNSS监测单元、供电单元、通信单元和监控中心单元。该系统可达到水平位移1mm、垂直位移2mm的监测精度,根据实测资料建立以变形速率为参数的监控指标,并在此基础上开发高精度三维实时监测与预警系统,为保障边坡安全稳定提供技术支撑。     

基于分布式光纤传感器的损伤监测研究

结构损伤的出现通常具有空间位置的任意性,使得传统的离散式传感器难以监测损伤的出现和发展,而分布式光纤传感器具有分布式、长距离、精度高和耐久性长等特点为大型复杂结构的分布式探测提供了可能。首先介绍了BOTDA分布式光纤传感技术与应变的关系,并论述了光纤传感器周围结构出现损伤变形时,传感器会监测到应变显著变化这一监测传感特性,然后制作了钢梁的裂缝损伤模型,应用BOTDA分布式光纤传感系统对梁在正常工作状态、单一裂缝和多裂缝工作状态进行了监测。结果显示,在裂缝损伤出现的位置,分布式光纤传感器监测到显著的应变变化,并可以准确定位损伤位置。通过对钢梁的损伤模拟的研究表明,在单一损伤和多损伤情况下,BOTDA光纤传感器可以准确有效的识别钢梁中裂缝的位置,能够实现复杂结构的分布式损伤监测。更多还原     

光纤光栅传感技术在水利监测中的应用

光纤光栅传感技术是国际上近十年发展起来的新型传感技术，既用光纤感测信号又用光纤传输信号，是以光纤为载体的传感技术的最杰出代表。目前该技术已经相对成熟，并成功地应用于多个相关行业。介绍了在光纤光栅技术平台上研制出的传感器的特点、工作原理及其在水利监测中的应用，着重于光纤光栅传感技术在水位遥测及大坝安全监测上的应用。     

瀑布沟水电站水管式沉降仪监测自动化系统的实施

针对瀑布沟水电站大坝安全监测测点多、分布广,人工监测耗时耗力的问题,介绍了该电站建设自动化监测系统的必要性。同时介绍了水管式沉降仪自动化系统的结构、组网方式、模块类型、测量方式、运行步骤及效果。     

地下厂房施工过程的三维非线性数值模拟分析

根据冗各电站地下厂房开挖支护的施工顺序,以隐式杆单元模拟锚杆,以壳单元模拟混凝土喷层,采用三维非线性有限元技术,对洞室群的开挖支护动态过程进行了模拟计算。通过三维非线性有限元计算分析得到:洞室群动态开挖过程中围岩应力变形的分布规律,围岩塑性区的发展规律,锚杆受力变化情况。计算结果表明:整个开挖过程中,洞周围岩位移变化规律正常,量值较小,塑性区主要分布在洞室周边,围岩稳定性较好;但在洞室交叉口处围岩的变形较大,出现较大范围的塑性区,在此基础上提出了支护措施优化方案,并对优化方案的效果进行了评价。     

Evaluation of freshwater mussel relocation as a conservation and management strategy

The relocation of unionacean mussels is commonly used as a conservation and management tool in large rivers and streams. Relocation has been used to recolonize areas where mussel populations have been eliminated by prior pollution events, to remove mussels from construction zones and to re-establish populations of endangered species. More recently, relocation has been used to protect native freshwater mussels from colonization by the exotic zebra mussel Dreissena polymorpha. We conducted a literature review of mussel relocations and evaluated their relative success as a conservation and management strategy. We found that 43% of all relocations were conducted because of construction projects that were forced to comply with the Endangered Species Act 1973 and that only 16% were monitored for five or more consecutive years. Most (43%) relocation projects were conducted from July to September, presumably a period when reproductive stress is relatively low for most species and the metabolic rate is sufficient for reburrowing in the substrate. The mortality of relocated mussels was unreported in 27% of projects; reported mortality varied widely among projects and species and was difficult to assess. The mean mortality of relocated mussels was 49% based on an average recovery rate of 43%. There is little guidance on the methods for relocation or for monitoring the subsequent long-term status of relocated mussels. Based on this evaluation, research is needed to develop criteria for selecting a suitable relocation site and to establish appropriate methods and guidelines for conducting relocation projects.     

基于模型试验的河床砂砾石层基本特性研究

为了经济可靠地确定深厚覆盖层的基本特性参数,以大渡河双江口水电站坝基河床砂砾石层基本特性研究为工程背景,进行大尺寸模型试验,研究河床砂砾石层的旁压模量和动探击数随密度、级配以及上覆压力的变化规律。根据室内模型试验结果,结合现场旁压试验及钻孔试验成果,推断出坝址区河床砂砾石相关层位的密度,并依此进行砂砾石室内力学试验,获得设计所需力学参数。研究成果可为深厚覆盖层基本特性测试提供新的方法。     

基于BP神经网络-马尔科夫链模型的隧道围岩位移预测

在隧道工程施工中,围岩位移预测起着很重要的作用。将BP神经网络-马尔科夫链模型引入到隧道围岩位移预测中来,通过对训练样本的学习,利用BP神经网络实现了对位移时间序列的滚动预测,同时得到了实测值与预测值的相对误差;在此基础上利用马尔科夫链对相对误差进行修正,有效地提高了预测结果的精度。并将该模型应用于某公路隧道拱顶下沉位移时序预测中,结果表明该模型具有精度高、科学可靠的特点,为隧道围岩变形的预测提供了新的途径。     

Short communication. Pipelines as a refuge for freshwater snails

In the lower River Murray, Australia, populations of gastropods have declined markedly over the past 40 years. Of the native fauna of about 18 species, only the ancylid Ferrissia petterdi remains common (but in patches), and another five species feature in sporadic local resurgences. Until recently the viviparid Notopala was thought to be extinct. The introduced physid Physa acuta is widespread, but in low numbers. The decline probably is associated with flow regulation, high turbidity and the introduction of common carp. Snail populations have persisted, however, in irrigation pipelines fed from the river, where they periodically cause blockages. This paper reports the discovery of the only known populaion of Notopala hanleyi in a pipeline where the inner wall accumulates microbial and other organic matter, providing high quality food for snails. In the Murray before regulation most of the periphytic biomass was probably microbial, as fluctuating water levels would have maintained littoral communities in a highly productive, early state of succession his postulated that, by stabilizing seasonal water levels, regulation has promoted the production of filamentous green algae, an inferior food source, and so displaced snail populations from the open aquatic environment.     

浙江省水域调查录入系统的设计和应用

浙江省水域调查录入系统将调查数据与电子地图相整合,对分类水域数据进行统计计算,并对输入数据进行合理性和完整性检查,得到调查范围内现有水域的详细数据,实现了水域调查数据输入、计算、统计和查询的数字化管理,提高了工作效率和工作质量,为各地下阶段水域保护规划编制和水域管理工作提供了数据支持。对该系统的设计原则、功能和技术设计等作了介绍。     

Automated system for removal and pneumatic transport of fly ash from electric precipitator hoppers

A system for removal and pneumatic transport of fly ash is examined, in which air pulses act on batches (pistons) of ash formed in a duct. Studies are made of the effect of several physical parameters on the force required to displace a piston of ash and these serve as a basis for choosing a system for removal and pneumatic transport of ash simultaneously from several hoppers of an electric precipitator. This makes it possible to separate the ash particles according to size without introducing additional components. Formulas are given for calculating the structural and dynamic parameters of this system and measurements of indirect dynamic parameters are used to calculate the input-output characteristics of the system. In order to optimize the system, configurations for summing several ducts into a single transport duct for pneumatic ash transport are proposed. Some variants of dry ash utilization and the advantages of producing of size-separated particles are considered. __________ Translated from élektricheskie Stantsii, No. 2, pp. 26–30 (2008).     

The flood pulse advantage and the restoration of river-floodplain systems

The ‘flood pulse advantage’ is the amount by which fish yield per unit mean water area is increased by a natural, predictable flood pulse. Evidence for this increase is presented from tropical and temperate fisheries. It is argued that increasing multispecies fish yield by restoring the natural hydrological regime is consistent with increasing production of other trophic levels and with restoration from ecological and aesthetic viewpoints. When applied to a river-floodplain system, this restoration would provide a large, self-sustaining potential for recreation, commercial exploitation, and flood control. An interim ‘natural flood pulse’ restoration approach is proposed for systems modified for navigation. This approach approximates the natural hydrological regime in a river reach and is intended as a first step in the long process of restoring the watershed.     

基于CT-连续加荷水泥乳化沥青混凝土细观损伤规律研究

利用CT技术对水泥乳化沥青混凝土的细观损伤过程进行实时扫描观测,获得了混凝土试件在连续加荷下的CT图像。通过采用直观分析法、CT数分析法、CT数与损伤变量关系3种方法分析表明,水泥乳化沥青混凝土的破坏过程可分为压密、扩容、裂纹扩展、破坏4个阶段,同时混凝土在受压过程中具有韧性,在极限荷载之前各断面处于压密和微扩容的强化阶段,极限荷载之后混凝土从损伤到破坏发展比较平稳。     

浅谈天湖水电站水轮机运行故障及处理措施

简述天湖水电站投运以来各种故障的表现形式，分析其原因，提出了相应的处理方法及措施，并对合理利用国内外设备提出建议。