针对高氟地区农村饮水安全工程建设管理的思考

本文通过分析我国高氟地区饮水现状,总结了该地区饮水工程出现的建设、管理问题,通过分析对比现有技术特点,提出了解决高氟地区饮水工程问题的建议和对策,对于高氟地区饮水安全工程的长效运行有积极意义。     

塔里木盆地西部地区氟分布规律及成因分析

通过对塔里木盆地西部部分地区含氟量超标致病及地表水、地下水及土壤中氟分布进行勘察,找出高氟水的分布规律,并分析出氟离子富集原因,为保护塔里木盆地水资源及防病改水提供可靠依据。     

大庆地区地下水中氟的迁移转化机理研究

通过大量的调查试验工作，对大庆地区地下水中氟的来源、分布、迁移转化机理，以及氟浓度变化趋势等方面进行了分析，表明氟在地下水系统中具有明显的空间分布规律，铁、锰、钙、ＰＨ值是影响氟存在与迁移的重要因子。     

北京大兴区第四系地下水氟分布特征及成因分析

北京大兴地区西南部第四系地下水氟含量普遍超标,严重制约区域供水。通过取样化验,分析了研究区高氟地下水的分布特征和分布范围。综合区域水文地质、地貌、地质构造、地层岩性及水化学等方面特征,分析了高氟水的成因,认为浅层高氟水的形成机理属于F-蒸发浓缩富集型,而深层高氟水中的氟则是来自于基底富氟白云岩。研究成果对区域供水井的设计施工,以及保障区域供水安全具有现实社会意义。     

临汾市尧都区氟离子分布状况及形成原因

阐述了地下水中氟离子含量与氟本身的特性及地质、地貌、水文地质、人为因素的关系,分析了临汾市尧都区氟离子形成的原因,针对不同地区氟离子形成原因,提出了相应的解决方法:高氟区可采用集中供水方式;东部黄土台地区应采取打井或调水方式提供低氟水,最后提出治理含氟工业废水的方法。     

辽宁地区高氟水处理技术研究

长期饮用高氟水可以引起地方性氟中毒,而氟超标水无法通过简单水处理来作为农村供水水源,因此研究高氟水地区水处理技术模式对实现农村饮水安全具有极其重要的意义。总结辽宁地区农村饮水安全工程建设以来存在的氟超标问题,选取合适的技术路线,形成适宜辽宁地区农村饮水安全氟超标工艺。     

山西农村饮水高氟水问题及处理措施分析

探讨了山西高氟水形成原因及其对饮用者的危害,提出解决山西农村饮水高氟水问题的必要性和高氟水处理面临的挑战,结合山西省实际情况,分析了高氟水处理的改水源工程措施和水质处理措施所适应的条件和地区,为高氟水地区开展改水降氟提供决策依据。     

黑龙江省农村饮水型氟化物超标情况调查分析

为查明黑龙江省地下水水源氟化物分布、超标及改水效果等情况,对黑龙江省集中供水工程地下水水源水质检测结果进行了分析。研究结果表明,我省农村饮水型氟超标地区分布在肇东市、安达市、梅里斯区3个市(区)、23个乡镇、127个行政村、336个自然屯。肇东市氟超标地区分布在6个乡镇、39个行政村、84个自然屯。安达市氟超标地区分布在14个乡镇、82个行政村、245个自然屯。梅里斯区分布在3个乡镇、6个行政村、7个自然屯。水源改水前氟化物浓度1.50～5.44mg/L。改水后氟化物浓度低于1.10mg/L,氟化物指标达标。通过降氟改水工作,全省饮水型氟超标问题得以全面解决。     

HAP-F新型饮用水除氟设备的试验研究

羟基磷灰石(HAP)作为一种新型除氟材料,其除氟性能稳定且除氟吸附容量大。利用HAP-F除氟工艺,采用气水联合反冲洗实现机械磨损再生处理的方法,研发适合中国农村地区使用的除氟设备。通过对HAP-F除氟设备在各种工况及参数模式运行下的试验研究,总结出适合中国农村高氟水地区的HAP-F除氟设备的最佳运行模式,以达到降低成本、高效除氟、循环利用、节约水源的目的。简要介绍了HAP-F新型饮用水除氟设备的研发,及最佳运行模式的试验研究。     

电渗析与反渗透技术在沧州农村分质供水中的除盐降氟效果分析

河北东部平原靠近渤海的沧州地区,由于浅层地下水苦成,深层地下水高氟,农村饮用水质严重不达标。为了改善饮水状况,近年来该市采用电渗析与反渗透技术进行除盐、降氟,实施农村分质供水,大大提高了人们的生活饮用水质量。通过两种除盐、降氟技术的应用实例,分析比较了两种技术设备的水质处理效果,为进一步推广应用提供技术参考。     

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.     

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.     

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。     

Desiccation and recolonization of phytobenthos in a regulated desert river: Colorado River at Lees Ferry,Arizona, USA

We tested the recolonization of the phytobenthic community in the tailwaters of Glen Canyon Dam following long- and short-term experimentally induced desiccation. The response of Cladophora glomerata, Oscillatoria spp., miscellaneous phytobenthos species and periphyton was studied over 18 weeks using three treatments: (1) undisturbed control cobbles from the submerged zone; (2) cobbles desiccated and replaced into the submerged zone; and (3) cobbles desiccated and replaced into the varial zone. Periphyton density and compositional response resulting from these treatments were also examined. Desiccation treatments were significantly different in biomass from controls throughout the study. The biomass of desiccated and replaced river cobbles averaged <30% of the controls for C. glomerata and periphyton during the 18-week recolonization period. In contrast, the biomass of the control Oscillatoria and miscellaneous phytobenthos species averaged only 3 and 50% of that in the desiccation treatments, respectively. Cladophora, the dominant alga, comprised 77% of the phytobenthic biomass. A significant positive relationship between discharge, Cladophora and periphyton biomass was present in all treatments, while there was a negative relationship with discharge for Oscillatoria and miscellaneous phytobenthos species. There was a significant inverse correlation, as well as a pattern of separate biomass dominance, between C. glomerata and Oscillatoria. Cladophora was the dominant phytobenthos species on cobbles below the baseflow and Oscillatoria was dominant on cobbles in the varial zone. In general, the Cladophora biomass decreased under intermittent drying conditions, while Oscillatoria declined under permanently wet conditions. Diatom composition was not significantly different between treatments; however, their density was lower on desiccated cobbles. Diatom density on desiccated cobbles in the submerged and varial zones averaged 69 and 42% of that of the controls, respectively. Recovery and maintenance of benthic resources are hindered by fluctuating flow regimes driven by electricity and irrigation requirements. Repeated desiccation of the phytobenthos has major effects on the bottom-up interactions in the Colorado River ecosystem. © 1998 John Wiley & Sons, Ltd.