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1.
In 2019 a Scientific Research&Demonstration Platform was deployed near islands and reefs in South China Sea by a joint research group of 7 institutes and universities in China.It is a simplified small model of a two-module semi-submersible-type VLFS.The test on site has continued for more than one and half years since then for long-term observations to validate the developed key technologies for design and behavior predictions of floating structures deployed near islands and reefs.An integrated information system was set up to continuously collect and inspect the data of the encountered waves,structure responses,connector forces,mooring line forces,anti-corrosion status of the platform,the performance efficiencies of a floating breakwater nearby and a wave energy converter attached on the breakwater.In this paper,the status of the on-site measurements and validations of the key technologies are briefly described.  相似文献   

2.
《中国水利》2008,(10):1-2
北京时间2008年5月12日14时28分,四川省汶川县发生里氏8级大地震. 地震发生时,全国除吉林、黑龙江和新疆维吾尔自治区没有震感外,其他省、自治区、直辖市和周边许多国家都有不同的震感,我国四川、重庆、甘肃、陕西、云南、青海、宁夏等地震感强烈,破坏特别严重的地区达10万平方公里.  相似文献   

3.
同志们: 全国违规水电站清查整改工作座谈会就要结束了,上午胡四一副部长作了一个非常重要的讲话,全面肯定了清查整改工作成绩,对下一步工作提出了明确的任务要求并进行了全面部署;国家安监总局王力争副司长通报了全国一季度安全生产情况,传达了国务院领导同志关于安全生产工作的最新指示,提出了下阶段安监部门进一步配合水利部门做好违规水电站清查整改工作的意见和建议;国家电监会吴晔副处长提出了进一步理顺体制机制,加强市场监管,从根本上消除违规水电站的意见;福建、湖南、广东、广西、重庆水利厅(局)和贵州铜仁地区水利局介绍了他们的做法和经验,会议还就贯彻胡四一副部长的讲话精神、进一步做好清查整改工作进行了讨论,大家提出了许多好的意见和建议.应该说,这次会议时间虽短,但开得紧凑,效果很好.  相似文献   

4.
近几年郊外游玩成为都市人热衷的休闲项目之一,尤其是冬季滑雪.目前仅北京周边郊区就有大小规模不等的滑雪场13家,分布在密云、怀柔、延庆、昌平、顺义等郊区县.  相似文献   

5.
各省、自治区、直辖市及计划单列市、副省级会城市、新疆生产建设兵团发展改革委、经贸委(经委),国家电网公司、南方电网公司、中国华能集团公司、中国大唐集团公司、中国国电集团公司、中国科学院、中国工程院:  相似文献   

6.
本文对辽宁省农村水电发展的现状及存在的问题进行了分析,从行业自身、市场和社会、生态环境等方面进行研究,提出建议.  相似文献   

7.
通过阐述水务信息化建设的重要意义,分析目前潮白河供水管理所信息化建设的现状和存在问题.针对实际情况,提出信息化建设的方法和建议.  相似文献   

8.
地震诱发的堰塞湖   总被引:1,自引:0,他引:1  
堰塞湖是一种自然界经常发生的自然现象。主要是在一定的地质与地貌条件下,由于火山喷发物、滑坡体、泥石流、冰川堆积物等形成的自然堤坝横向阻塞河谷后,造成上游段壅水而形成的湖泊.随着成因的不同可分为火山堰塞湖、冰川堰塞湖等。其中.由于地震引发河道两侧山体滑坡或崩塌、滑坡体或崩塌体落人河道形成拦水堤坝、河水聚集成湖的现象称为地震堰塞湖。  相似文献   

9.
在先秦诸子中,兵家是最受诸侯欢迎的一家。历史为兵家提供了驰骋的舞台;而战争,则为兵家提供了锻造的熔炉。春秋战国之际,一大批军事家走上历史的前台。但大浪淘沙,有兵圣之誉者,唯孙子一人。  相似文献   

10.
与博弈投骰、登高远游、泛舟湖上、吹箫抚琴、吟诗作画、饮酒狂舞等娱乐活动相比,玩抚自己多年搜集的历代珍玩实在是充满静谧雅趣的消遣,它可使人心畅神怡,  相似文献   

11.
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。  相似文献   

12.
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.  相似文献   

13.
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。  相似文献   

14.
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。  相似文献   

15.
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.  相似文献   

16.
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。  相似文献   

17.
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。  相似文献   

18.
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).  相似文献   

19.
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.  相似文献   

20.
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。  相似文献   

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