排序方式: 共有13条查询结果,搜索用时 33 毫秒
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太浦闸监控系统与远程传输网络 总被引:3,自引:3,他引:0
介绍了太浦闸监控系统的监控网络、闸门控制、安全监测和视频监视等部分的体系架构与具体实现,以及远程传输网络的总体架构与基于iFIX平台网络信息发布的实现。 相似文献
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南通节制闸闸门自动控制系统设计 总被引:1,自引:1,他引:0
以南通节制闸为应用背景,介绍了液压启闭闸门自动控制系统的设计方法,给出了系统的三级网络结构及相应的操作控制功能。 相似文献
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本文采用系列模型试验方法,对瓯江二桥主桥墩局部冲刷问题进行了研究。试验结果表明主桥墩最大冲刷深度与上游径流量及主桥墩轴线走向有关:对径流为百年一遇洪水流量,主桥墩轴线走向与水流流向一致时,其最大冲刷深度为11.69m;主桥墩纵轴线与流向夹角为20°时,最大冲刷深度为14.81m。试验得到施工围堰局部冲刷与流量的关系,得出最大冲刷深度,并提出围堰局部冲刷的防护措施。 相似文献
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伶仃洋为弱潮河口,潮差较小,平均潮差为0.86~1.69 m,最大潮差为2.29~3.36 m.伶仃洋潮汐动力远远强于径流动力,潮流是塑造和控制滩槽格局的主要动力因素.通过伶仃洋河口潮流物理模型试验,研究港珠澳大桥建设对伶仃洋河口潮流动力环境的影响.研究结果表明:港珠澳大桥的建设对潮底动力环境影响的范围和强度表现为东部人工岛附近较强,西部桥区附近相对较小;近桥局部区域潮位及流场的变化比较明显,远离桥轴线5 000 m以外区域变化较小. 相似文献
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港珠澳大桥横跨伶仃洋河口,该水域南北长75 km,东西宽约50 km,模拟总水域面积大于2 100 km2.针对此类型的桥梁潮流物理模型设计,桥墩桩群处理是关键问题之一.对于小尺度单桩如仅按几何相似比尺进行设计,则无法满足阻力相似,因此本模型在满足潮流运动相似原则的基础上,充分考虑大桥桩群总阻力相似的方法进行概化处理,并经过水流试验验证.结果表明该物理模型桩群概化处理和边界控制合理,较好地模拟了大桥建设对水流运动影响,为跨海特大型桥梁模型设计提供了切实可行的有效方法. 相似文献
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风速变化具有随机性、间歇性等不确定性特征,导致风力发电机出力的不确定性,从而影响风电场的稳态运行。为了表达和处理电场中风速和风力发电机出力的不确定性信息,利用区间方法建立了风电场风速不确定性和风力发电机出力不确定性区间模型,并提出了风电场区间潮流分析算法。以青岛某实际风电场的运行数据为基础进行算例分析,验证了所提出的模型和算法的有效性,表明了定量分析风力发电机出力不确定性对风电场稳态运行的影响具有应用价值。 相似文献
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The strongest change in Meiyu periods in the mid-lower Yangtze Basin (MLY) since 1885 occurred in the late 1970s: a stage of weak Meiyu from 1958 to 1978 abruptly transformed into a stage of plentiful Meiyu from 1979 to 1999. The average Meiyu amount of the latter 21 years increased by 66% compared with that of the former 21 years, accompanied by a significant increase in the occurrence of summer floods in the MLY. This change was closely related with the frequent phenomenon of postponed Meiyu ending dates (MED) and later onset dates of high summer (ODHS) in the MLY. To a considerable degree, this reflects an abrupt change of the summer climate in East China. Further analysis showed that the preceding factors contributing to inter-annual changes in Meiyu in the two 21-year stages delimited above were also very different from each other. The causes of change were associated with the following: China’s industrialization has greatly accelerated since the 1970s, accompanied by an increase in atmospheric pollution and a reduction of the solar radiation reaching the ground. The sand area of North China has also expanded due to overgrazing. The enhanced greenhouse effect is manifested in warm winters (especially in February). Meanwhile, the January precipitation of the MLY has for the most part increased, and El Ni?o events have occurred more frequently since the late 1970s. A correlative scatter diagram consisting of these five factors mentioned above clearly shows that the two stages with opposite Meiyu characteristics are grouped in two contrasting locations with very different environmental (land-atmosphere) conditions. It is quite possible that we are now entering a new stage of lesser Meiyu, beginning in 2000. 相似文献