大坝安全定期检查中的水下检查

指出第二轮水电站大坝安全定期检查水下检查的依据和目的，介绍检查设备、检查成果的提供，可作为该轮水下检查的参照。并且，回顾了若干水下检查设备历年实际使用情况。     

In Situ Quantum Efficiency of Lake Superior Phytoplankton

In situ quantum efficiencies were measured in Lake Superior over a 4-day period in 1978 and on one occasion in 1980. In 1980, experimental artifacts caused by exposing deep phytoplankton to elevated irradiances were minimized by the use of SCUBA divers. The trends of quantum efficiency with depth agreed well with theory. In the nutrient-limited upper portion of the euphotic zone, quantum efficiencies increased with depth, whereas in the light-limited lower portion of the euphotic zone, quantum efficiencies were relatively constant. Maximum quantum efficiencies calculated with downwelling irradiances ranged from 0.041 to 0.069 moles C fixed ? Einst abs^?1 with a mean maximum quantum efficiency of 0.0538 ± 0.0025 moles C fixed ? Einst abs^?1. Maximum quantum efficiencies in morning experiments ranged from 0.041 to 0.053 moles C fixed ? Einst abs^?1 and were slightly less than noon values, 0.057 to 0.067 moles C fixed ? Einst abs^?1. Correction for scalar irradiance would reduce all quantum efficiencies by 25%.     

How shark conservation in the Maldives affects demand for dive tourism

Shark-diving tourism provides important economic benefits to the Maldives. We examine the link between shark conservation actions and economic returns from diving tourism. A combined travel cost and contingent behaviour approach is used to estimate the dive trip demand under different management scenarios. Our results show that increasing shark populations could increase dive-trip demand by 15%, raising dive tourists’ welfare by US$58 million annually. This could result in annual economic benefits for the dive-tourism industry of >US$6 million. Conversely, in scenarios where shark populations decline, where dive tourists observe illegal fishing, or if dive operators lack engagement in shark conservation, dive trip demand could decrease by up to 56%. This decline causes economic losses of more than US$24 million annually to the dive tourism industry. These results highlight the dependence of the shark-diving industry on the creation and enforcement of appropriate management regimes for shark conservation.     

陇东黄土高原第四系潜水系统特征

陇东黄土高原第四系潜水系统分为黄土潜水系统和河谷潜水系统,黄土潜水系统又分为黄土塬区潜水、黄土丘陵区潜水。分析了黄土潜水系统和河谷潜水系统的赋存特征、补径排条件、动态特征等。结果表明:大气降水是黄土潜水的主要补给来源,潜水的TDS和总硬度年际间变化均不大,水质普遍较好,是该区居民的主要饮用水源;河谷潜水主要接受大气降水的垂直补给、地表水的入渗补给、沟谷潜水的侧向补给、灌溉回归水的补给及基底白垩系地下水的越流补给,潜水水质均较好,TDS一般小于1.0 g/L,是河谷区人畜饮用水和城镇供水的主要水源。     

论海岛潜水作为海洋旅游新业态

旅游是全球海岛发展的支柱产业之一,滨海旅游业作为海洋产业的组成部分,呈现多元化的发展趋势,潜水尤其是海岛潜水越来越得到游客青睐。潜水作为一种新兴的休闲娱乐方式,是传统海岛产业升级、滨海旅游业发展的重要抓手。在厘清海岛潜水产业的基本概念后,明确海岛潜水产业形成和发展的关键因素,通过对比分析国外海岛潜水产业发展的有益经验,总结我国产业发展存在的不足,建议通过突出地方立法并整合社会资源等政策来规范并促进海岛潜水行业的健康发展。     

塔贝拉水电站扩建工程水库深水探测技术研究

在简述深水水下机器人探测和混合气潜水技术的基础上,针对塔贝拉水电站叠梁门安装工程水下探测中水下情况不明、水深大、能见度低等特点,探索了水下机器人初探结合潜水员进行复杂作业的库底深水探测技术,并在叠梁门门槽淤积情况探测、门槽水下锈蚀状况与上方淤积体勘测、百米深水下清障和除锈除垢作业等方面成功应用。研究成果对水库和浅海水下探测工程具有借鉴意义。     

南昌县小兰工业园区东山电排站新站选型初探

通过详细地比较分析,可研阶段东山电排站新站拟采用2000ZDBX-100带行星齿轮减速机构的大型潜水电泵,为我国单机容量最大、转轮直径最大的潜水泵.此泵型具有装置效率高、节能、噪音小、占地面积少、美化环境、安装周期短等优点,在类似泵站选型中具有推广价值.     

Artificial Reefs as Recreational Scuba Diving Resources: A Critical Review of Research

This paper reports on the increasing practice of developing and promoting artificial reefs as sites for scuba diving tourism and recreation. A comprehensive definition of artificial reefs is presented that encapsulates the diversity of structures used by marine recreationists, particularly scuba divers, followed by a review of existing literature that specifically examines artificial reefs as a resource for the conduct of recreational scuba diving. Three main thematic areas were identified in the existing literature: social dimensions, socioeconomic impacts and environmental engineering. A typology of artificial reefs is offered to better describe and categorise artificial reef structures according to unit characteristics that may influence recreational use such as material used, appearance, complexity and cost. The paper presents a conceptual model that identifies the components of an artificial reef scuba diving experience and discusses the potential of artificial reefs to act as tourism resources and management tools to redistribute scuba diver numbers away from natural reefs. Directions for future research are suggested, emphasising collection of data on aspects of the artificial reef scuba diving experience to better inform marine resource management.     

水下封堵门技术在水口电站的创新再应用

采用水下安装浮体封堵门技术对水口水电站2号泄水底孔事故检修门槽进行封堵和修复后,重新改造利用原浮体封堵门又对位于大坝左岸的1号泄水底孔进行了封堵检修并获成功。该方法直接在水下利用浮式闸门封堵底孔进水口,形成旱地施工条件,并可重复利用,节省工期和造价,为大坝类似结构水下除险消缺找到了技术可行、安全可靠、经济有效的新方法、新工艺。     

灌北、善南泵站潜水贯流泵装置的水力特性研究

通榆河北延送水工程灌北泵站和善南泵站扬程低且年运行时间较长,为得到较高的泵装置效率,采用了单泵设计流量为10m3/s、叶轮直径为2m的卧式潜水贯流泵装置。采用三维湍流流动数值计算和模型试验的方法,分别对这种型式泵装置的内外水力特性进行了研究,表明卧式潜水贯流泵装置具有水流平顺、均匀和流道水力损失小的优点,水力性能十分优异。