共查询到20条相似文献,搜索用时 187 毫秒
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本文研究12脉冲矩形脉冲断开(GTO)、电压源逆变站(VSI)在分接少容量(10-15%)高压直流电力上的应用;简单评价并联多端直流系统(MTDC)的控制方式。VSI和线路换流逆变站(LCI)的特性比较表明,GTO VSI对分接应用具有某些技术优点,为了证明这点,利用直流系统电磁暂态程序进行了详细的数字模拟。接入GTO VSI的高压直流系统在各种计划和非计划扰动下的模拟特性证明,小容量并联分接GT 相似文献
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GIS在南非水资源管理中的应用 总被引:1,自引:0,他引:1
GIS在南非水资源管理中的应用D·R.麦克佛森主题词水资源利用,水资源管理,数据库,计算机应用,管理自动化,南非前言近年来,南非共和国开始将地理信息系统(GIS)应用到水系分析、水井分布图的绘制、解决水用户之间的纠纷以及研究植树造林等方面。在这个人口... 相似文献
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万安水电站采用六氟化硫气体绝缘变电站(简称GIS)。结合万安水电站的实际情况,对于按地开关的运用进行了分析。分析认为,快速接地开关(FES)对保护GIS内部故障尚存在问题.故对变电站线路侧按地开关的选型进行了论证,提出了将FES改型为维修型接地开关(ES)的依据。此外,设计还提出了将接地开关的接地体与外壳绝缘的要求,这对主导电回路的通流能力的判断、绝缘电阻测量等均提供了方便。 相似文献
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地理信息系统(GIS)春强大的地理数据管理和空间分析操作能力,为水文学提供了辅助建模工具,本文讨论了应用GIS建立水文模型的些基本问题,包括水文地理数据描述和存储方式、水文遥感监测数据的应用、水文模拟机制及水文模型的系统集成方式。 相似文献
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给水管网图形信息系统的研究 总被引:6,自引:1,他引:5
本文介绍了给水管网图形信息系统(GPGIS)的设计思想、总体结构及关键技术;阐述了利用AUTOCAD的二次开发功能开发GPGIS系统时,应考虑的几个问题:图形管理、属性信息管理及图形与属性信息的链接。对GPGIS系统中专业化的水力平差计算,管网故障分析等功能进行了说明。 相似文献
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MAPGIS软件是中国地质大学(武汉)信息工程学院研制开发的适合中国国情的地理信息系统(GeographicInformationSystem)。其系统的含义是研究计算机技术和空间地理分布数据的结合,通过一系列操作和分析方法为地球科学、环境科学和工程... 相似文献
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安康水电站330、110kV高压电器设备均采用六氟化硫(SF6)全封闭组合电器(GIS)。330kVGIS主接线为双母线,共有9个间隔,其中进线4个、出线3个、母联1个、PT1个;110kVGIS主接线为双母线,共有9个间隔,其中进线2个、出线5个、母联1个、PT1个。该设备投产10年来,通过对设备运行中出现的问题的处理和检修,积累了一定经验,如:充气阀门、GIS壳体、测压管道泄漏,GIS设备损坏等,并对设备的运行和检修工艺流程进行了总结。可供有关单位参考。 相似文献
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GIS在水资源综合开发中的应用 总被引:7,自引:1,他引:6
在论述地理信息系统GIS的概念及其特点的基础上,详细描述了GIS在水资源开发领域的应用,GIS以其直观,形象,高效的工作方式,多样化的信息来源和强大的处理空间数据的能力,被越来越多地应用到水资源的开发领域。从80年代后期至今,GIS在水资源开发中的应用从较为简单的防洪GIS发展到现在的水资源规划,水环境,水土保持、水利工程规划与管理等各个方面,尤其是在洪涝灾害防治工水资源规划设计方面成效显著,大大 相似文献
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将地理信息系统与水深遥感技术结合运用 ,可实现将水下地形图数字化及数字高程模型的生成与叠合分析 .当应用到海岸工程中 ,可得到工程所处水域不同时段、不同冲刷深度 (或淤积厚度 )的冲淤分布和冲淤量 . 相似文献
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Groundwater management and development by integrated remote sensing and geographic information systems: prospects and constraints 总被引:15,自引:3,他引:12
Madan K. Jha Alivia Chowdhury V. M. Chowdary Stefan Peiffer 《Water Resources Management》2007,21(2):427-467
Groundwater is one of the most valuable natural resources, which supports human health, economic development and ecological
diversity. Overexploitation and unabated pollution of this vital resource is threatening our ecosystems and even the life
of future generations. With the advent of powerful personal computers and the advances in space technology, efficient techniques
for land and water management have evolved of which RS (remote sensing) and GIS (geographic information system) are of great
significance. These techniques have fundamentally changed our thoughts and ways to manage natural resources in general and
water resources in particular. The main intent of the present paper is to highlight RS and GIS technologies and to present
a comprehensive review on their applications to groundwater hydrology. A detailed survey of literature revealed six major
areas of RS and GIS applications in groundwater hydrology: (i) exploration and assessment of groundwater resources, (ii) selection
of artificial recharge sites, (iii) GIS-based subsurface flow and pollution modeling, (iv) groundwater-pollution hazard assessment
and protection planning, (v) estimation of natural recharge distribution, and (vi) hydrogeologic data analysis and process
monitoring. Although the use of these techniques in groundwater studies has rapidly increased since early nineties, the success
rate is very limited and most applications are still in their infancy. Based on this review, salient areas in need of further
research and development are discussed, together with the constraints for RS and GIS applications in developing nations. More
and more RS- and GIS-based groundwater studies are recommended to be carried out in conjunction with field investigations
to effectively exploit the expanding potential of RS and GIS technologies, which will perfect and standardize current applications
as well as evolve new approaches and applications. It is concluded that both the RS and GIS technologies have great potential
to revolutionize the monitoring and management of vital groundwater resources in the future, though some challenges are daunting
before hydrogeologists/hydrologists. 相似文献
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Zhang Ji-sheng Wang Bo Jeng Dong-sheng Liu Philip L. -F. Dong Ping 《水动力学研究与进展(B辑)》2010,22(1):126-131
The phenomenon of wave-seabed-structure interactions have occurred in the marine environment with a coastal permeable (or partially permeable) structure, which has attracted great attention from coastal engineers involved in the design of marine structures. In this study, a porous seabed model based on Biot’s consolidation equation and pore-elastic theory is integrated into the COBRAS wave-structure model. This integrated model is verified by the laboratory experiments. Some dominant factors affecting the wave motion and its induced seabed response are examined by using this model, including wave parameters and structure properties.
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数字化测绘技术是伴随着计算机、网络技术的发展及测绘仪器的智能化而兴起的一门新兴的测绘技术。目前我国工程测绘的手段和方法产生了深刻的变化,特别是由于全球定位系统( GPS)、地理信息系统( GIS)、摄影测绘与遥感( RS)以及数字化测绘和地面测绘先进技术的发展,并且工程测绘的服务领域也相应进一步延伸,而且正朝着测绘数据采集和处理的自动化、实时化和数字化方向发展。文章针对数字化测绘技术在工程测绘中的应用进行探讨,并结合相关的案例进行了概括性阐述。 相似文献
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This study presents a novel application of marine geoelectromagnetic technique, in an attempt to delineate freshwater extension of the coastal sub-aquifers beneath the SE Mediterranean Sea, along central Israel. The novel marine Ex-Bz time domain electromagnetic (TDEM) geophysical method was applied, demonstrating high sensitivity to the presence of sub-seafloor electrically resistive structures up to several kilometers offshore (shallow marine environment). The study included 19 marine measurements located offshore between Ashdod in the south to Tel-Aviv in the north, where a previous onshore study detected fresh groundwater below seawater intrusion at the coast line. The offshore measurements were conducted to distances of up to 3 km from the shoreline. It was found that the lower sub-aquifer contains fresh groundwater (resistivity >10 Ω-m) to a distance of 2.8 km offshore along the 30 km strip, and is probably constrained by lateral geo-facial changes. 相似文献
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水文学模型与水力学模型耦合进行流域洪水模拟可以更加精细地反映流域洪水的产生和运动过程。用现代计算机信息管理、遥感技术(RS)、信息可视化和地理信息系统(GIS)等技术,实现水文学和水力学模型的耦合。采用了数据—模型—应用三层结构的总体集成结构,通过模型应用过程的模块化处理和数据有效交换,建立了基于RS和GIS的集数据处理、模拟、参数率定和预报调度功能于一体的综合计算平台。 相似文献