东北地区发展高效节水灌溉的思考

自2011年开始,东北地区率先实施区域规模化高效节水灌溉,文章概述了东北地区高效节水灌溉的发展,分析了高效节水灌溉方式及适用性,对推进高效节水灌溉提出了几点思考。     

发展高效节水灌溉之哲学思考

灌溉的物质条件决定了灌溉方式这个意识选择;灌溉发展具有规律性,但任何一种灌溉方式都有其适用范围,都与周围各种条件和现实相联系,只有不断创造条件,才能有效推进高效节水灌溉发展;只有从失败中学习并依靠新的认识指导新的实践,才能循环往复推进灌溉事业的进步和提升.因此,应在实践中充分认识发展高效节水灌溉的艰巨性和曲折上升性,增强发展高效节水灌溉的自党性、支撑力和自信心,积极创造条件,因地制宜加快推进高效节水灌溉的健康发展.     

阳泉市农业节水灌溉现状及对策浅析

节水灌溉是节约农业用水、转变农业增收方式,使传统农业向优质高效农业转变的重大战略性举措。在新形势下,大力发展农业节水灌溉,充分发挥工程的最大效益,探索一条体现山区特色的节水灌溉新路子,对促进农业向现代化发展意义重大。介绍了阳泉市基本情况,分析了全市农业节水灌溉现状,针对目前存在的问题提出了相应的解决措施。     

滑县大力发展节水农业的新探索

节水灌溉技术是比传统的灌溉技术节约用水和高效用水的灌水方法、措施和制度等的总称。是否节约灌溉用水,用水是否高效是以单位作物产量总耗水量(从水源算起直到田间)多少来衡量。因为节水与否和高效与否,都是相对的概念,所以节水灌溉技术也是不断发展、不断提高的。本文主要针对我国现行的一些节水灌溉技术和滑县的节水灌溉现状,进行了对比研究和探索。     

探索高效节水灌溉发展之路推进蔗区经济发展方式转变

高效节水灌溉是广西蔗区经济发展方式转变的根本性措施.分析了崇左市江州区发展蔗区高效节水灌溉中“政企民合作共建”的主要做法,阐述了推行江州模式,发展高效节水灌溉应把握的主要问题.     

永济市高效节水及末级渠系建设项目必要性分析

介绍了当前永济市农业灌溉状况,分析了永济市目前灌溉方式存在的主要问题,根据灌溉现状得出高效节水及末级渠系项目建设的必要性,应当积极推广高效节水灌溉方式,减轻农业灌溉成本,节约地下水资源,有效补充地下水量。     

黑河中游张掖属区高效节水灌溉项目综合效果评价

为发现高效节水灌溉项目中存在的主要问题,选取黑河流域中游地区张掖属区高效节水灌溉项目为研究材料,设置项目准则层,构建评价体系,并采用项目现场实地调查、查阅水行政主管部门资料、访谈、入户调查等方式获取一手资料,应用层次分析法和模糊综合法评价高效节水灌溉项目综合效益.评价结果与实际调查相符,该评价体系可用于一般高效节水灌溉...     

南京市江宁谷里高效节水灌溉科技示范基地

项目主要取得了以下成果: (1)高效节水智能化灌溉系统开发,包括:高效节水智能化灌溉系统研发、高效节水灌溉网站研发、移动终端及APP软件研发. (2)高效节水灌溉展示基地及展厅建设,可进行多种作物、多种灌溉方式、多种灌溉设备、多种灌溉技术等的展示. (3)依托示范基地,开展宣传推广、科普教育、技术服务与培训.     

南乐县高效节水灌溉途径探索

南乐县地处华北平原,境内水资源短缺。探索南乐高效节水灌溉发展的新路子,需要综合考虑自然地理、水资源条件、经济社会发展水平以及农田水利发展现状及农业生产特点,因地制宜选择高效节水灌溉技术模式,科学确定管理措施,以寻求高效节水更大的发展空间,从而促进县域经济和社会的发展。     

杨丕龙副厅长赴樟树市督导检查高效节水灌溉项目建设

<正>根据江西省高效节水灌溉工程建设部门联席会议第一次会议安排部署,2016年12月29日,杨丕龙副厅长率农水处相关同志赴樟树市督导检查高效节水灌溉项目建设。杨丕龙一行现场察看了樟树市店下灌区低压管道灌溉工程,详细了解灌区阁山农业科技示范园高效节水灌溉工程建设情况,与园区项目负责人探讨产业发展与灌溉需求,与高效节水灌溉项目负责人研究产业灌溉方式、项目     

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。