海底裸置与埋置管线自沉过程对比研究     

唐丕鑫  杨树耕  宋艾恒  刘晓峰  徐蒙  王晗 《海洋工程》2015,33(2):89-96

海底管线是海洋油气输运系统的重要组成成分,其稳定性和安全性尤为重要。通过有限元软件ABAQUS,应用Mohr-Coulomb模型,模拟海底裸置与埋置管线自沉过程。通过平衡初始地应力,设置管土接触,考虑重力和浮力作用,进行土体固结分析,计算裸置与埋置管线的土体与管线竖直位移,并进行管线悬跨研究。计算结果显示,对于裸置管线,参数的改变使土体更容易发生塑性屈服,土体的竖直位移量更大;对于埋置管线,当管线埋深较浅、管线上方土体重量不大时,参数的改变使管线平均密度与周围土体密度相差越大土体越容易发生塑性屈服,土体的竖直位移量越大。当管线悬空时,悬跨长度过大易使管线两端支撑土体被压溃,管线易产生大变形而失稳,因此在管线安装与维护过程中,一定要采取措施降低悬跨长度,保证管线运营安全。  相似文献   

The influence of Stokes drift on oil spills: Sanchi oil spill case     

Yiqiu Yang  Yan Li  Juan Li  Jingui Liu  Zhiyi Gao  Kaixuan Guo  Han Yu 《海洋学报(英文版)》2021,40(10):30-37

Spilled oil floats and travels across the water’s surface under the influence of wind, currents, and wave action. Wave-induced Stokes drift is an important physical process that can affect surface water particles but that is currently absent from oil spill analyses. In this study, two methods are applied to determine the velocity of Stokes drift, the first calculates velocity from the wind-related formula based upon a one-dimensional frequency spectrum, while the second determines velocity directly from the wave model that was based on a two-dimensional spectrum. The experimental results of numerous models indicated that: (1) oil simulations that include the influence of Stokes drift are more accurate than that those do not; (2) for medium and long-term simulations longer than two days or more, Stokes drift is a significant factor that should not be ignored, and its magnitude can reach about 2% of the wind speed; (3) the velocity of Stokes drift is related to the wind but is not linear. Therefore, Stokes drift cannot simply be replaced or substituted by simply increasing the wind drift factor, which can cause errors in oil spill projections; (4) the Stokes drift velocity obtained from the two-dimensional wave spectrum makes the oil spill simulation more accurate.  相似文献   

AUV矢量推进水动力计算及水平回转操纵性试验          下载免费PDF全文

李雨田  雷敏  冯朝  韩用波 《数字海洋与水下攻防》2020,3(4):288-294

针对矢量推进模式下的 AUV 水动力性能和操纵性能,开展了 AUV 矢量推进水动力 CFD 计算, 对矢量推进水平回转操纵性进行了评估,加工了矢量推进样机,并进行湖上操纵性验证。理论计算和试验数据表明：矢量推进具备极高的低速操纵性,该研究为矢量推进在 AUV 上的应用提供了理论和技术基础。  相似文献   

淹没不整合型层序——一种特殊的加深淹没   总被引：1，自引：0，他引：1  

符颖  韩林 《海相油气地质》2007,12(3):15-20

淹没不整合型层序以其凝缩层直接覆盖于层序界面上,即凝缩层+高水位体系域层序类型为特征,以不含有任何暴露证据而区别于层序地层学定义的Ⅰ型和Ⅱ型层序界面,成为碳酸盐地层层序中的一种特殊类型的三级旋回层序界面。以淹没不整合型层序的特征描述、鉴别方法和实例分析阐述了淹没不整合是一种旋回层序的特殊类型即加深淹没型层序界面。这种淹没不整合型层序在油气运移方面起着重要作用。  相似文献   

海水冷冻预淡化系统的试验研究     

孙朋元  袁瀚  张继  孙坤元  庞海林 《中国海洋大学学报(自然科学版)》2021,51(3)

本文提出了一种基于冷冻脱盐的海水双级冷冻预淡化系统。该系统利用蒸发结晶器对海水进行冷冻,并通过振动分离与洗涤实现冰晶与卤水的分离,以此实现海水的初步脱盐,可作为反渗透淡化的预处理系统。同时,海水冷冻淡化过程中消耗的冷量可重新回收用于空调制冷,淡化成本得以有效降低。本文建立了海水双级冷冻预淡化系统的数学模型,获得了试验系统的关键设计参数,以此搭建了试验平台并完成了试验测试,并对海水双级冷冻预淡化系统进行了经济性分析。试验结果表明:经过海水冷冻预淡化系统,预淡化海水产量可维持在21~27 L/h之间;预淡化海水盐度可从35降低到约11;预淡化过程可回收总冷量7.91 kW;反渗透淡化总成本可降低约33%。  相似文献   

Revisiting the Relationship Between Urbanization and Economic Development in China Since the Reform and Opening-up     

LIANG Longwu  CHEN Mingxing  LU Dadao 《中国地理科学(英文版)》2022,(1):1-15

The relationship between urbanization and economic development has become a hot topic in the scientific community due to its great practical significance,and economic and social value.However,this relationship continues to change dynamically.In the new stage of urbanization,it is urgent to reveal the causal relationship quantitatively and diagnose the future direction systematically.Based on this,this paper calculates the contribution rate of China’s urbanization to economic development from 1978 to 2019 and uses the panel data cointegration test method to explore the causal relationship between urbanization and economic development in China.The study has three principal results.First,the contribution rate of urbanization to economic growth has maintained the overall growth trend from1978 to 2019,but the growth rate of urbanization’s contribution to economic growth has been relatively low since 2012.It is an important reason that the real estate sector has moved into a new stage of transformation.Second,the cointegration test shows that economic development is a significant factor in advancing urbanization and the urbanization is the product of economic development.Urbanization has a positive feedback effect on economic development,but this effect does not pass the 5%significance level test.The impulse response function shows that the impact of urbanization on economic development is relatively small and stable,indicating that it is limited that the boost of economic development by land-centered urbanization.Third,China’s urbanization and economic development have both shown rapid growth for some time,but their relationship is still the low level of coordination,which has also led to a downward trend in the contribution of new-type,people-oriented urbanization to economic growth in recent years.In the future,China’s urbanization and economy need to maintain relatively medium-low speed growth in the medium-long term,and we should boost the coordinated development of urbanization and economy from low level to high level.  相似文献   

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党星海  赵丽洁  孔令杰  韩博 《大地测量与地球动力学》2013,33(2):147-150

?????????????????????GPS ??????????????Ч???????????????GPS?????????????в???С???????????????????????????Ч?????????????????????????????  相似文献   

冀西安妥岭斑岩型钼矿成矿地质条件浅析   总被引：1，自引：0，他引：1  

李会恺  乔增宝  韩亮  鹿波  赵体群 《山东国土资源》2009,25(9):20-25

安妥岭钼矿位于燕辽钼（铜）成矿带南端,与附近的野弧斑岩型钼矿等具有相同的地质背景和成矿条件。文章阐述了古结晶基底、中生代岩体以及NNE、NW和近EW向构造与成矿的关系,提出安妥岭钼矿是在斑岩型矿床基础上,叠加了主要沿NW向构造发育的岩浆热液成矿作用所形成的具有复杂成矿系列的非典型斑岩钼矿床。  相似文献   

广州市制造业与生产性服务业协同集聚与空间相似性   总被引：1，自引：1，他引：0  

钟韵  赵蓓蕾  李寒 《地理科学》2021,41(3):437-445

基于企业微观大数据,从空间相似性的视角,运用核密度法、双变量空间自相关法和地理探测器等分析方法,对广州市6个制造行业和5个生产性服务行业的空间协同关系展开分析,在街镇尺度下从行业层面探讨生产性服务业与制造业在城市内部的协同集聚.研究发现:行业集聚中心的空间布局形态显示,广州的制造业与生产性服务业布局具有空间相似性.制造...  相似文献   

大型建筑设施物联网应用的探索     

张涵  易志辉  陈晓勇  徐超 《地理信息世界》2021,28(1):85-89

经过近30年的发展,我国桥梁健康监测系统研究与应用取得了可喜的进步,越来越多的大型桥梁开展自动化监测系统建设工作.然而目前部分监测系统均存在着重硬件、重单体、监测精度低等问题.本文结合国内外研究现状,在现有监测体系的基础上,构建了多因子、多维度桥梁健康监测体系,并提出了一种结合5G网络技术的集自动监测、巡检、养护、管理、预警和决策指挥于一体的桥梁健康系统,实现桥梁振动、位移、山体滑坡和地震等突发事件的实时报警,提供专家库一键式解决方案.  相似文献