三峡工程重庆库区消落区土地整理研究

通过对三峡工程重庆库区消落区土地整理的研究,从保护和整治生态环境、综合治理库岸、确保城(集)镇安全、缓解"人多地少"基础性矛盾、实现城乡统筹发展等几方面阐述了消落区土地整理的必要性。     

践行民生水务服务首都“三农”发展

水是生命之源、生产之基、生态之要.在城乡一体化发展新格局下,建设“民生水务、科技水务、生态水务”,加强基础设施建设,构建村镇安全供水、农业高效节水及水源保护等5大体系,为首都“三农”发展奠定坚实的水务保障.     

青山嘴水库工程创新移民安置方式效果和问题分析

水利工程移民安置,实行以"城镇安置化"和"城市宗地安置"的安置方式是云南移民安置的创新,是解决我国西部(云南、四川、西藏、贵州等地)地区水电发展与工程建设占地移民安置矛盾较为可行的一种安置方式、为当地移民群众乐于接受的安置方式。     

城市排水防涝综合规划治理研究

随着我国城镇化进程加快,城市内涝灾害频发,严重威胁着人民的生命财产安全和城镇安全,城市排水防涝综合规划治理已经成为人们关注的焦点。针对这一问题,阐述了目前城市排水防涝现状及主要存在的问题,介绍了城市雨水径流控制与资源化利用、城市排水管网系统规划和城市防涝系统规划等综合规划治理内容,并以某城市排水防涝规划治理作为典型案例进行分析,对城市排水防涝规划治理具有重要参考价值。     

城镇供水末端水质保障与改善技术探讨

饮用水水质问题得到人们越来越多的关注,饮用水安全保障不但涉及水源水、净水厂和市政管网系统,还包括城镇供水末端水质保障系统。研究、建立和完善城镇供水末端水质保障体系是城镇饮用水全流程多级屏障的重要组成部分,也是充分体现"从源头到龙头"总体目标的饮用水安全保障体系的终端核心。在分析现阶段城镇供水末端存在的水质和安全保障设施问题的基础上,提出了城镇供水末端系统的水质安全与保障的建议和措施。     

阿塔山水库下泄洪水对下游昆都仑河流域的影响分析

文章通过计算阿塔山水库不同频率洪水对应的最大下泄量,得出阿塔山水库在设防标准洪水内调洪减峰,可减轻下游河道和昆都仑水库的防洪压力,保证下游城镇安全。当阿塔山水库发生超标准洪水时,昆都仑水库大坝仍能安全运行。     

广东省农村供水现状分析与发展思考

农村供水是一项重大民生实事,事关人民群众的身体健康和生活福祉。该文结合农村供水现状数据精准核查工作和现场调研成果,对广东省农村供水现状进行分析总结,研究并分析现阶段亟待解决的突出问题,并进一步提出农村供水发展与思考,以期对全省新时期农村供水发展思路提供借鉴和参考。     

商南县城供水存在问题与对策

随着城市规模的不断扩大,商南县城的供水已经不能适应城市发展的需要.本文客观分析了商南县城供水存在的主要问题,对供水区的水文和地质情况进行了探讨.本着降低成本、节约、环保的目的提出了相应的解决办法,以便满足城区的生产、生活供水,促进地区经济发展.     

日本建成由河道外蓄水的前川坝

日本山形县为保护上山市不再遭受洪水威胁,建成分流方式的河道外蓄水水库。由于河流无合适坝址,而在上游通过水渠把洪水引入定侧支流的前川河上的前川水库蓄起来,从而保护了下游的城镇安全,并使上山温泉胜地得到实惠。     

北京市中心城再生水发展历程及"十二五"发展规划

本文通过对北京市中心城"十一五"之前以及"十一五"期间再生水利用事业的发展历程的总结,以及对其"十二五"规划的概括,阐述北京市中心城再生水发展所形成的格局、特点、效益与经验.同时,从再生水专业经营公司的角度,就供水观念、供水保障、再生水特性等影响供水安全性的要素等提出建议.     

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。