三峡工程对库区水流水质影响预测

利用开发的三峡水库整体一维水流水质数学模型，对三峡水库建成前后的水流水质变化趋势进行预测分析。重点介绍三峡工程建成后，库区水流条件巨大变化对污染物输移转化特性和水质分布的影响。预测结果表明，三峡工程建成后，三斗坪水位175m条件下，回水区断面平均流速比建库前减小4倍左右，平均有机污染物自净降解速率和大气复氧速率比天然河道状况减小1倍。由于污染物在库区滞留时间成倍延长，有机污染物排入水库后的自净降解总量较天然河道状况增大，因而，建库后加水区内断面平均有机污染物浓度较天然河道状况明显下降，但是，断面平均溶解氧浓度与天然河道状况相比也明显降低，对于守恒类污染物，建库前后水质变化不大。因此，三峡工程对库区水质影响有利也有弊。     

官厅水库水质污染状况及趋努分析

根据近10年官厅水库上游河道与库区的水质变化情况,结合相关水质超标项目,进行水库水质污染状况分析,预测未来供水水质状况与水库水质发展趋势,并提出解决办法.     

南水北调中线水源区水质预报方法研究

提出了对丹江口水库水质进行预报的方案。首先对水源区的污染物总量进行准确测算,其次对进入库区的水量进行预报,最后根据预报水量和预测的污染物总量,采用水库水质数学模型计算预报日期的污染物含量,从而预报坝前水质状况。     

官厅水库水质污染状况及趋势分析

根据近10年官厅水库上游河道与库区的水质变化情况，结合相关水质超标项目．进行水库水质污染状况分析，预测未来供水水质状况与水库水质发展趋势，并提出解决办法     

丹江口水库水体中微量有机污染物种类初探

丹江水库是南水北调中线工程的水源地，其水质优劣对工程效益有直接影响，长江流域水环境监测中心首次采用色－质联用仪，分别于１９９５年枯水期和丰水期，对丹江口水库水体中的微量有机污染物，进行了初步探查，基本掌握了丹江口水库微量有机物污染分布状况及库区主要污染物种，为库区及水源地的水控制与水资源保护及规划提供了极为重要的科学依据。     

镇北水库入库污染物分布规律及保护对策

无论是点源还是非点源的污染物最终都将通过入库河流，地表散流及库区面的降水、沉降载入水库，通过水质监测和水质模拟，分析了入库污染物的分布规律。根据镇北水库水资源保护规划目标，论述了保护水库水质的措施。     

东风水库水质分析及治理建议

本文依据《地表水环境质量标准》(GB 3838—2002),采用《地表水环境质量评价办法(试行)》对东风水库库区以及入库河流的水质现状进行评价,结果表明,东风水库水质达到地表水Ⅲ类标准,满足饮用水水质要求。分析得出了导致东风水库水质变化的主要污染物指标、污染物排放特征以及水质的变化趋势,可为下一步的水库水生态修复提供理论依据,结合近年来的治理工作经验,辩证施策地提出了东风水库水质保护的治理建议。     

大伙房水库水源保护对策研究

本文针对目前大伙房水库库区水量减少及入库口水质恶化的现状,利用水质模型进行了水库环境容量计算,制定了污染物削减计划,最后提出了具体保护对策和措施。     

数学模型在水质预测中的应用

拟建石佛寺水库位于辽河干流，属大型水利工程。在水库及下游河道水质主要污染物预测中，首次采用一维多点源稀释自净数学模型和完全混合式数学模型，定性、定量地模拟预测水库建成后水质变化规律。本数学模型适合辽河水系特点，较以往的数学模型更为合理和适用     

非恒定流下泄对金沙水电站库区水质影响研究

金沙水电站为日调节电站,为研究日内各时段库区水质受上游观音岩水电站非恒定流下泄及金沙水电站反调节影响的分布和变化规律,采用数值模拟的方法对金沙水电站库区水质进行预测,选取典型断面,分析得出水库高水位运行时水质较好、低水位时水质较差的变化规律,并提出优化电站调度运行过程、开展污染源治理等措施对库区水质进行保护。     

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。