生活饮用水中"红虫"杀灭初步研究

我国一些城市的水源地以及给水厂水池中,甚至在用户端的水龙头中都曾经发现"红虫"的存在,严重影响了饮用水的水质.在天津市市区收集到3处用户水龙头放出的"红虫",在对该种"红虫"进行了实验室条件下的初步生物学研究的基础上,对其成虫进行了实验室条件下的杀灭试验研究.分别研究了不同温度(10℃、20℃、30℃)条件下,不同余氯对"红虫"成虫的杀灭效果;并且初步研究了光照、基质等环境影响因子对杀灭效果的影响.     

常温下生物陶粒反应器中亚硝酸型硝化的试验研究

采用生物陶粒反应器,研究了常温下亚硝酸型硝化的实现过程。试验结果表明,在水力负荷0．6m／h,气水比(3-5):1,水温20-25℃,进水CODCr负荷1．91-5．59kg／(m3·d),氨氮负荷0．77-1．33kg／(m3·d)的条件下,生物陶粒反应器对氨氮的平均去除率可达到80．91％,出水中亚硝酸氮占到亚硝酸氮和硝酸氮总和的90％以上。对生物陶粒反应器中各种不同无机氮化合物沿程变化的研究进一步表明,在反应器中实现了稳定的亚硝酸盐积累。对影响亚硝酸型硝化的各因素进行了分析,认为溶解氧控制是常温下反应器实现亚硝酸型硝化的最关键因素。     

温度对强化混凝-悬浮填料床生物氧化工艺运行的影响

利用中试装置分别研究了冬季低温(7～15 ℃)、水温回升(14～22 ℃)和较高水温(27～32 ℃)等条件下的工艺运行效果.结果表明当生物段HRT为3.3～6 h、预处理PAC投加剂量30 mg/L、填料投配率30%的条件下,温度对CODCr、SS、TP的处理效果影响很小,对生物硝化和反硝化的影响较大.当水温为7～13 ℃时,出水NH3-N平均在7.84 mg/L,TN的去除率只有18.4%;而水温20 ℃以上,出水NH3-N浓度＜1 mg/L;TN的去除率达到50%.低温时污水经过组合工艺处理后,出水的氮、磷仍能达到＜城镇污水处理厂污染物排放标准＞(GB 18918-2002)一级B标准.     

拉萨河下游水温变化特征及其影响因子分析

以拉萨河下游1956—1982年水温、气温及流量资料为基础,利用累计距平和滑动平均法分析了水温变化特性及变化趋势,并分析了水温对气温及流量变化的响应关系。结果表明:1拉萨河下游河段水温沿程升温率为1.0~2.8℃/100 km,研究河段的下游段因气温升高,且多为分汊型河道,故水温显著升高,研究站点间春季水温温差较大,冬季水温温差较小;2研究河段年均水温为7.3~8.4℃,夏季水温变幅大于冬季的;320世纪50年代中期到60年代中期水温降温率为-0.74℃/10 a,60年代中期到70年代初期水温升温率为0.47℃/10 a,70年代初期到80年代初期水温倾向率为0.005℃/10 a;4多年平均水温高于多年平均气温,同时期内水温的变化趋势与气温的相同,与流量的相反。     

鲤鱼胚胎发育与温度和溶氧的关系

试验模拟了黄河径流条件(温度和溶氧)对黄河表征性鱼类——鲤鱼受精卵发育的影响。结果表明:鲤鱼受精卵发育与温度和溶氧关系密切。在设置的温度梯度内(16℃,20℃,24℃,28℃),鲤鱼受精卵出膜时间与水温呈负相关,孵化的合适水温范围为20℃～24℃,孵化率较高(64.43%～76.97%)。水体中溶氧较为充足时,约6.28mg/l～6.75mg/l,鲤鱼胚胎正常发育。不同溶氧浓度对受精卵发育影响差异不明显,但当水体中溶氧不足时(约小于5.01mg/l),则严重影响鲤鱼受精卵正常孵化。     

混凝土壩施工中的綜合性混凝土預冷工厂

混凝土壩的冷却,随着我国水利建设的发展,逐渐成为施工中的一个重点问题。作者在有关埋设水管冷却一文(参考资科1)中,曾指出近十余年来世界各国筑壩的趋势是较多的采用在混凝土拌制成熟料前对拌和水及骨料的预冷,与局部采用埋设水管冷却相配合。我国近几年的水壩建设,从佛子嶺壩夏季施工中对砂石料喷水降温及拌和水内加冰(在气温34°～38℃,水温29°～33℃时加冰,将水温降至14°～22℃,使混凝土的出机和入仓温度,由不作上述措施的32°～34℃,降至28°～31℃)开始预冷,到最近     

高岩温发电引水隧洞支护结构全过程温度场分析

针对我国西北地区出现的高岩温引水发电隧洞,以布伦口—公格尔水电站的高岩温引水发电隧洞为背景,基于施工过程仿真,以110℃,90℃和60℃的初始岩温、5℃和10℃运行水温对引水发电隧洞全过程温度场分布规律的影响进行研究,揭示围岩不同初始温度场和设计运行水温对高岩温引水隧洞全过程温度场分布影响规律。结果表明初始岩温越高,支护结构内外温差越大;受运行低水温冲击作用,运行初期支护结构1d内出现了高速率的降温,严重影响支护结构安全性;设计运行水温对支护结构温度场分布有一定影响。     

秦岭细鳞鲑较高温度下仔稚鱼培育

本研究采用集中孵化,分组驯养的方法对秦岭细鳞鲑在较高水温下从孵化到仔稚鱼发育过程和日常管理及饵料做了研究。在较高温度下,秦岭细鳞鲑从受精卵孵化至卵黄囊消失的整个过程速度较快,所需积温为471.2℃.d,略少于正常值。鱼苗出膜后开始投喂不同饵料至其发育到3.5cm大小,采用活饵与人工配合饵料交替投喂有利于仔鱼开口,后期换用人工配合饵料有利于疾病控制和驯化。     

二滩水库温度原型测试定位误差初探

由于大型深水水库测船定位困难,水温、流速测量只能采用动船测试方法。为确保测船在一定摆动范围内量测之水温满足测验精度要求,需研究船舶定位、测时及环境温度对测验精度的影响。本文在所研究的水库中央选一50m×50m试验区,采用差分GPS定位技术分成编号为1-28的正方形网格,随机测量每网格的水温。试验结果表明采用船舶测试水库同一断面水温,在施测始末环境温度差值小于6℃,必须在2h内完成;当施测始末环境温度差值大于6℃时,水库断面水温测试应在更短时间内完成。船舶摆动振幅在25m内,可以保证测试的水温满足精度要求。     

UBF厌氧反应器处理印染退浆废水的试验研究

研究上流式厌氧生物滤池反应器(UBF)处理难降解印染退浆废水,试验结果表明,在中温(35℃±3℃)条件下,用混合酸调节pH值,在水力停留时间为8 9h、CODCr负荷率为13 1kg/(m3·d)情况下,CODCr去除率达到了68%。     

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。     

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。     

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.     

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。