海底电缆观测系统的研究现状与发展趋势   总被引：3，自引：0，他引：3  

马伟锋  崔维成  刘涛  胡震 《海岸工程》2009,28(3):76-84

随着世界各国对海洋研究和开发的高度关注，海底电缆观测系统越来越为人们所重视。首先简要介绍了海底电缆观测系统的定义及其发展史，并与其它海洋观测系统进行了对比，然后对各国海底电缆观测系统的发展现状进行了概述，指出了海底电缆观测系统的关键技术，最后讨论了海底电缆观测系统的发展趋势并给出相关建议。  相似文献   

海底管线表面压力分布的理论分析     

任兴月  拾兵  韩艳  杨立鹏 《海洋科学》2010,34(2):15-18

为了获取海底管线表面压力变化特征,基于固体边界层基本方程,利用摄动方法推导了管线表面压力分布解析式,并利用物理模型试验数据对理论公式进行了检验。经对公式系数做出适当调整,压力系数的计算公式能反映出边界层分离点前后的分布规律。  相似文献   

Petrography and geochemistry of the late Eocene–early Oligocene submarine fans and shelf deposits on Lemnos Island,NE Greece. Implications for provenance and tectonic setting     

A. Maravelis  A. Zelilidis 《Geological Journal》2010,45(4):412-433

Provenance and tectonic history of the late Eocene‐early Oligocene submarine fans and shelf deposits on Lemnos Island, NE Greece, were studied using sandstone framework composition, sedimentological data and sandstone and mudstone geochemistry. The resulting tectonic–sedimentological model is based on the late Eocene–early Oligocene Lemnos Island being in a forearc basin with the outer arc ridge as a major sediment source. Modal petrographic analysis of the studied sandstones shows that the source area comprises sedimentary, metamorphic and plutonic igneous rocks deposited in the studied area in a recycled orogenic environment. Moreover, within the above sediments, the minor occurrence of volcanic fragments suggests little or no influence of a volcanic source. Provenance results, based on major, trace and rare earth element (REE) data, suggest an active continental margin/continental island arc signature. All the samples are LREE, enriched relative to HREE, with a flat HREE pattern and positive Eu anomalies, suggesting that the processes of intracrustal differentiation (involving plagioclase fractionation) were not of great importance. Results derived from the multi‐element diagrams also suggest an active margin character, and a mafic/ultramafic source rock composition, while the positive anomaly of Zr that can be attributed to a passive continental margin source, is most likely associated with reworking and sorting during sediment transfer. Palaeocurrents, with a NE–NNE direction, indicate a northeast flow, towards the location of the late Eocene–early Oligocene magmatic belt in the north‐east Aegean region. Conglomerates are composed of chert, gneiss and igneous fragments, such as basalts and gabbros, suggesting this outer arc ridge as a likely source area. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

海底地下水和海水混合营养盐变化的模拟实验研究          下载免费PDF全文

张锋  翁焕新  陈力琦  季仲强  张志奇 《海洋学报》2010,32(3):167-175

1 引言 海底地下水排泄(submarine groundwater dis-charge,SGD)早在几世纪前就被发现,直到20世纪80年代,LOCIZ工作组成立并通过一系列的研究,让人们才逐渐认识地下水向沿海海域排泄是海岸带陆海相互作用的一个重要过程[1-2].近年来随着监测技术的发展,特别是同位素示踪剂技术的应用[3-4],已证实SGD是一个全球性的现象.  相似文献   

海底管线局部冲刷机理研究综述   总被引：1，自引：0，他引：1  

谷凡  周晶  黄承逵  李林普 《海洋通报》2009,28(5)

局部冲刷造成的悬空是海底管线失效的最大诱发因素。对均流及波浪作用下铺设在海床表面管线的局部冲刷起动机理、临界条件以及2D局部冲刷机理、流—管—土耦合机理和3D局部冲刷机理等做了分析和总结。  相似文献   

考虑阻尼海底悬跨段管道的动力特性及允许悬空长度   总被引：8，自引：0，他引：8  

杨新华  郭海燕娄敏 傅强 《海洋工程》2005,23(1):1-5

以海底悬跨段输液管道为研究对象,考虑管道结构阻尼、流体附加阻尼、管内流体流动及管道轴向力和压强的作用,对其进行受力分析,导出管道振动微分方程,进而得到管道动力特性方程。用Hermit插值函数对管道的动力特性方程进行离散得到有限元表达式,采用复模态分析法,求得管道的自振频率。为防止管道发生横向涡激振动,用约化速度作为控制条件,确定管道允许悬空长度。结果表明,管道允许悬空长度随着内流流速、轴向压力和管内压强的增加而减小,随着轴向拉力的增加而加大。  相似文献