平台障碍物对海气通量观测影响的数值分析

基于计算流体动力学模型（CFD）模拟了背景风风速为2 m·s-1、4 m·s-1、6 m·s-1下通量观测平台周围的风场分布,确定了不同风速下平台障碍物对观测影响最小的风向范围。发现风速不同,平台对背景风的影响范围不同,风速越大,平台对背景风的影响越大。运用涡动相关法计算不同风向条件下的湍流通量,定量分析由于平台干扰对海气通量计算的影响,发现选取迎风条件下的数据计算得到的海气通量会比实际偏低。     

Comparative Study on Collective Forest Tenure Reform and Water Rights System Reform in China

Collective forest tenure reform and water rights system reform are two types of resource system reform initiated by the Chinese government since the implementation of the reform and opening policy of the 1980s. Forest tenure reform has been completed and water rights system reform is ongoing. This study analyzes key points and problems with collective forest tenure reform and summarizes four typical successful reform measures and lessons that will have implications for the developing water rights system: the collective forest-cutting quota system, collective forest tenure compensation, collective forest tenure confirmation, and collective forest tenure trading center. A flexible water permission index, compensation measures in water rights trade, water rights approval, and various forms of water rights trading platforms are proposed as reform measures. This study fills a gap in comparative studies between two important resource system reforms in China and provides a reference for further reform and development of water rights systems locally and abroad.     

GIS技术下浙江省海洋灾害应急指挥平台的设计与实现

浙江省是海洋灾害多发的省份,为减少海洋灾害带来的损失,迫切需要建设一个海洋灾害应急指挥平台,本文介绍GIS技术下浙江省海洋灾害应急指挥平台的设计与实现。     

高速铁路GIS平台研究与实现

在铁路地理信息平台总体方案的基础上,以高速铁路为试点,研究建设高速铁路GIS平台。通过建设高速铁路专业专用地理信息数据,为铁路相关业务系统提供一种获取铁路专业专用地理信息数据的解决方案。同时,通过高速铁路GIS平台与业务系统的交互,进一步验证铁路地理信息平台总体方案中与铁路业务系统信息交互方案的可行性。文中给出了平台的逻辑架构设计、功能设计和空间数据组织模型设计,并简要介绍了平台实现过程中采用的3个关键技术。最后结合国内某高速铁路,实现了该平台的构建。     

智慧景区服务平台基础数据生产中的若干技术探讨

数据是智慧景区服务平台的核心与基础,服务平台要发挥其作用,首先要合理确定基础数据的内容和质量要求。本文以天地图·五大连池——智慧景区服务平台基础测绘工程项目为例,介绍了关于基础数据生产中的技术指标和规格,详述了总体技术路线及工艺流程,并对基础数据的质量控制进行了详细说明。     

Variations in architecture and cyclicity in fault-bounded carbonate platforms: Early Miocene Red Sea Rift,NW Saudi Arabia

The Early Miocene was a period of active rifting and carbonate platform development in the Midyan Peninsula, NW Saudi Arabia. However, there is no published literature available dealing with the detailed characterization of the different carbonate platforms in this study area. Therefore, this study aims to present new stratigraphic architectural models that illustrate the formation of different carbonate platforms in the region and the forcing mechanisms that likely drove their formation. This study identified the following features formed during active rifting: a) a Late Aquitanian (N4) fault-block hangingwall dipslope carbonate ramp, b) a Late Burdigalian (N7-N8) isolated normal fault-controlled carbonate platform with associated slope deposits, and c) a Late Burdigalian (N7-N8) attached fault-bounded platform with reef buildups, rimmed shelf developed on a footwall fault-tip within a basin margin structural relay zone that formed coinciding with the second stage of rifting. Variations in cyclicity have been observed within the internal stratigraphic architecture of each platform and also between platforms. High-resolution sequence stratigraphic analysis shows to be parasequences the smallest depositional packages (metre-scale cycles) within the platforms. The hangingwall dipslope carbonate ramp and the attached platform demonstrate aggradational-progradational parasequence stacking patterns. These locations appear to have been more sensitive to eustatic cyclicities, despite the active tectonic setting. The isolated, fault-controlled carbonate platform reveals disorganized stratal geometries in both platform-top and slope facies, suggesting a more complex interplay of rates of tectonic uplift and subsidence, variation in carbonate productivity, and resedimentation of carbonates, such that any sea-level cyclicity is obscure. This study explores the interplay between different forcing mechanisms in the evolution of carbonate platforms in active extensional tectonic regions. Characterization of detailed parasequence-scale internal architecture allows the spatial variation in syn-depositional relative base-level changes to be inferred and is critical for understanding the development of rift basin carbonate platforms. Such concepts may be useful for the prediction of subsurface facies relationships beyond interwell areas in hydrocarbon exploration and reservoir modeling activities.     

半潜式平台垂荡响应抑制措施研究

半潜式平台垂荡响应较大,对生产平台立管和采油树系统的选择、钻井平台钻杆升沉补偿装置等提出更高要求,增大了作业和维护成本。针对这一问题,在传统结构基础上提出了三种新的结构概念:1)在浮筒底部加垂荡板;2)沿立柱外延加垂荡板;3)改变立柱为变截面结构。通过数值分析对各平台模型水动力性能进行比较,结果表明,各新型结构对半潜式平台垂荡起到一定程度的抑制效果。由于在浮筒底部加垂荡板的方案效果比较突出,对该方案进一步做了优化和改进工作,并对平台在南海百年一遇波浪环境条件下的垂荡响应概率密度函数和响应极值进行了预报和对比研究。     

聚酯系缆损伤对绷紧式系泊系统动力响应影响的数值分析

由于聚酯缆绳具备优异的力学性能,促使以其为主体系缆的绷紧式系泊系统得以广泛应用和发展。但聚酯系缆具有复杂的黏弹性和黏塑性,且由于在安装和使用过程中可能产生不同程度的损伤,使得聚酯系缆的动刚度特性发生演变,从而对系泊系统的动力响应产生直接影响。以一系泊于1 020 m水深的Spar平台为例,运用ABAQUS软件建立了由聚酯缆绳组成的系泊系统有限元模型,并利用ABAQUS子程序将损伤缆绳动刚度经验公式进行导入计算,以更好地反映系缆真实的动刚度变化。基于该有限元模型,计算了在相同水流、波浪工况下,不同损伤度、不同损伤系缆的系缆张力历程和平台的横荡、纵荡位移响应,分析了不同损伤度、不同损伤系缆对系缆张力及平台位移的影响。这些成果对把握绷紧式系泊系统在聚酯系缆有损伤情况下的非线性动力响应及其安全应用具有重要的参考价值。     

基于海床基观测资料的辽东湾东部海流特征研究

基于海床基观测平台,对2010年秋季辽东湾东部海域的海流开展连续观测,并运用谱分析和调和分析方法对该海域的潮流和余流特征进行研究。结果表明:辽东湾东北部潮流属于规则半日潮流;而中东部和东南部两站潮流属于不规则半日潮流。三个站位优势分潮流均为M2分潮,并呈往复流特征;其最大流速介于38~55 cm/s之间,流向为东北-西南,最大流速发生时刻随深度增加而提前。最大可能潮流流速介于91~142 cm/s,流向与岸线走向大致平行。秋季辽东湾东部沿岸余流整体较弱,流向以西南向为主,从北往南三站余流流速分别约为3~5 cm/s,3 cm/s和2~5.5 cm/s。     

Study of Seabed Pullout Resistance on a Quadrate Foundation Using Adaptive Time-Stepping Method

We developed a solid-fluid analysis procedure that can simulate the seabed pullout resistance based on two adaptive time-stepping methods. One is heuristic time stepping, and the other is based on the truncation error estimation in temporal discretization. The pullout resistance is investigated through experiments and numerical simulations. The results show that the proposed adaptive stepping methods can deal with the un-convergence problems caused by the time increment and can improve the calculation efficiency. The base suction, related to the area of the negative pore water pressure, is generated under the structure and provides the pullout resistance.