深水防波堤堤心石级配调整试验

由于石料源头及堤心石堆场有限,造成堤心石堆高后细颗粒含量增加,堤心石质量难以满足合同及技术规范要求,因此,采取加强石料源头控制等措施以达到堤心石级配要求。为从根本上减少堤心料的筛分量,保证防波堤的施工进度,通过设置中间层、调整堤心石质量级配方法,进行相应断面模型试验验证,为防波堤工程的顺利实施提供技术支撑。     

规则波作用下组合式潜堤消浪性能试验研究

通过物理模型试验对梯形和矩形组合式潜堤的消浪性能进行研究,比较组合式潜堤与单排布置潜堤的消浪性能,分析堤顶水深、波高、间距及组合堤排数等因素对潜堤透射系数Kt的影响。试验结果表明:组合式潜堤的透射系数随着堤顶水深的增加而增加,随着波高的增大而减小;组合式潜堤排数越多消浪效果越好,可根据实际工程需要恰当地选择潜堤的布置排数。     

不规则波作用下潜堤透射系数的计算方法及统计分布

通过物理模型试验的方法,研究了不规则波作用下抛石潜堤的透射系数及堤后稳定波高的统计分布。潜堤采用梯形断面形式。通过因次分析,得出影响潜堤透射系数的因子为相对浸没深度(a/H)、相对宽度(B/H)、波陡(H/L)、相对水深(d/H)。根据物理模型试验的结果,得出潜堤前后的稳定波高及潜堤透射系数与主要影响因子的变化规律。其中影响潜堤透射系数最主要的因子为相对浸没深度(a/H)、相对宽度(B/H)。借助MATLAB数学软件平台,将数据进行回归分析,得出不规则波作用下潜堤透射系数的经验公式。最后,得出不规则波作用下潜堤后稳定波高的统计分布。     

桩基挡板透空堤与潜堤消浪特性数值计算研究

为改善港内水域平稳度,本文采用Fluent软件建立桩基挡板透空堤与潜堤的数值波浪水槽联合模型,在设计高水位及2年一遇波浪组合下,计算潜堤断面尺度(坡比、堤顶宽度、堤身高度)和潜堤位置变化的120组试验工况,研究潜堤的消浪特性,得到潜堤位于距透空堤1/6波长位置与潜堤高度2.5 m能够改善水域平稳度,满足堤后H4%波高均小于0.6 m。     

齿型构件混合堤翻坝水流力影响因素数值分析

齿型构件混合堤是长江深水航道一期工程中采用的一种新型混凝土构件混合堤,该新型结构尚处于研究初期阶段.为了解其受力特性、推广其在工程中的应用,基于CFX软件,对齿型构件混合堤翻坝水流力影响因素进行数值分析.结果表明,齿型构件混合堤翻坝水流力由动水压力及堤身前后静水压力差组成,随着入射流速、入射角度及相对堤高的增大,翻坝水...     

浅谈斜坡堤稳定性监测施工工艺

斜坡堤抛填时往往因不合理的施工顺序及速度而导致斜坡堤所处土层产生圆弧滑动,造成斜坡堤的破坏.本文结合洋山深水港四期工程大小乌龟联络堤稳定监测的经验,介绍斜坡堤稳定监测的方法,总结加载速率的确定方法及监测控制标准,可供类似工程参考.     

吴淞导堤监测技术及成果分析

吴淞导堤位于黄浦江下游端与长江口交界区域,引导两江交汇处水流及船舶航运.由于年代久远,水流冲刷、堤身沉降、堤面坍塌,出于吴淞导堤对于黄浦江航运的重要性,有必要对其进行监测,以便为其维护和整治提供依据.通过不同技术方法对吴淞导堤进行断面测量、水平位移、垂直位移、灯桩倾斜、裂缝和损坏等方面的监测,观察其稳定性和损坏程度.从观测成果分析,导堤整体处于稳定状态,损坏部位有所增大增多,有必要对导堤护坡进行整修.     

河口导堤工程对入海河流纳潮的影响及敏感性分析

以灌河口整治工程为例,采用大范围二维水动力数学模型,从定性、定量两方面分别研究了航道单纯疏浚工程及布置单、双导堤工程(结合疏浚)对潮汐动力为主河口地区入海河流纳潮量的影响,并就导堤高程对纳潮影响进行了探讨。研究结果表明,灌河口航道单纯疏浚工程会增加灌河纳潮量,增设单导堤后纳潮量将会进一步增加,而双导堤工程后,灌河的纳潮量既有可能增加也有可能减少,主要取决于导堤高程。就导堤高程对于灌河纳潮量的影响来说,东导堤高程位于低潮位及涨急附近潮位时最为敏感,而西导堤各级高程都较为敏感。方案比较显示,只要堤顶高程控制合理,灌河口双导堤工程实施以后可以保持灌河纳潮量基本不变。     

斜坡堤越浪流厚度及堤后次生波的试验研究*

通过断面物理模型试验,对于斜坡堤的平均越浪量、堤上越浪流厚度以及堤后次生波的波高、周期的变化情况等进行了较系统的研究,初步建立了堤上越浪流的厚度、堤后次生波的波浪透射系数、周期变化系数与无因次平均越浪量的关系.该成果可为工程实际及斜坡堤堤项越浪情况数学模型的参数调整提供依据.     

临淮岗复线船闸工程复建主坝、退建蓄洪堤总体方案

建设需按原等级复建主坝和城西湖蓄洪堤。经对地形及施工影响等方面的分析论证,确定了复建主坝沿现有坝轴线布置、退建蓄洪堤的轴线位置位于复线船闸南侧69m处。经对现状主坝、蓄洪堤方案及地形地质条件的分析论证,确定复建主坝和蓄洪堤采用均质土坝,坝身设置塑性砼防渗墙。     

In Political Seas: Engaging with Political Ecology in the Ocean and Coastal Environment

The world’s oceans and coasts are awash in a sea of politics. The marine environment is increasingly busy, changing, and a site of degradation, marginalization, injustice, contestation and conflict over declining resources and occupied spaces at local to global scales. Themes of political ecology, such as power and politics, narratives and knowledge, scale and history, environmental justice and equity, are thus salient issues to understand in ocean and coastal governance and management. This subject review examines research on these themes of political ecology in the ocean and coastal environment and reflects on how the insights gained might be applied to governance and management. Political ecology provides important insights into: the influence of power in ocean management and governance processes; the manner in which narratives, knowledge, and scale are used to legitimize and shape policies and management efforts; the effects of historical trajectories on present circumstances, options, and practices; and the nature of inequities and environmental injustices that can occur in the marine environment. Moreover, ocean and coastal researchers, practitioners, and decision makers ought to engage with the political processes and injustices occurring in the ocean. Moving from critical insights to constructive engagements will ensure that political ecology helps to plant seeds of hope in the Anthropocene ocean.     

设计模式在设备故障红外智能诊断软件中的应用

诊断软件由于其诊断对象的复杂性和诊断策略的多样性,为设计模式的使用提供了较大空间.将设计模式引入船用机电设备故障红外智能诊断软件的开发,并具体讨论了一些常见的模式如Adapter、Bridge、Strategy和Observer等在软件各个模块和环节中的应用.实验证明,设计模式的使用,简化、明晰了软件的结构,加强了软件的通用性、稳定性和灵活性,提高了软件的可理解性和可维护性,并使得丰富红外诊断软件的接口和功能变得更为容易,进一步拓宽了软件的使用范围.     

High-resolution surveys of the biogeochemistry of the New England shelfbreak front during Summer, 2002

We present the observations from a pair of field experiments at the New England shelfbreak front in June and August of 2002, each consisting of 14 cross-frontal surveys using the Lamont Pumping SeaSoar. Measurements of the front's physical, chemical, and bio-optical characteristics were made at high spatial and temporal resolution. The front, based on water-column hydrographic distributions, was found within a few km of the 200 m isobath during both cruises. We present here composite sections, based on averages of individual sections shifted in space to a common frontal location, of the cross-frontal distributions of these properties as a measure of the mean state of the front in both June and August. The observations show the familiar temperature, salinity, and density distributions of the summertime front, dominated by surface thermal heating. Nutrient and bio-optical distributions show the combined effects of water-mass exchange and biological processes. T, S, silicate, and phosphate distributions are suggestive of cross-frontal exchange of slope- and shelf waters, although transport mechanisms and pathways are not apparent. These properties, along with nitrate and optical measures of the suspended particle distributions, show vertical displacements of isopleths as the front is approached: property contours slope upwards toward the front from the shoreward side, and downwards toward the front from the seaward side. Again, actual water-movement pathways are not constrained by these suggestive patterns. Bio-optical distributions show elevated indicators of photosynthetic efficiency both seaward and shoreward of the front, but the front itself is a minimum in biomass. Accumulation of photosynthetic biomass appears to be controlled primarily by nitrate scarcity in waters within and above the pycnocline. At the base of the pycnocline, light limitation appears to be the controlling factor, although the base of the euphotic zone is deeper than the biomass maxima and the base of the pycnocline. Mechanisms explaining this phenomenon are unclear, but tenuous evidence suggests low stratification at the depth of the 1% light level may not allow phytoplankton to optimize for the low-light, high-nutrient conditions at depth. Cross-frontal differences in nutrient and bio-optical parameters, particularly in August, suggest distinct phytoplankton assemblages, and the presence of calcite-forming or nitrogen fixing groups to the community structure, especially in very shallow waters across the front and in pycnocline waters seaward of the front.     

面向复杂装备AR辅助维修的混合跟踪技术研究

装备维修是生产制造、作业运转的基础,特别是在船舶、航空等领域。由于在维修过程中装备结构复杂、维修人员经验技术不足和缺少直观维修手段导致容易导致维修效率低下和操作出错。因此,通过研究基于增强现实的装备维修方案,直观交互地进行维修作业,能够有效地提升维修的质量和效率。由于装备体型较大,结构复杂,给跟踪定位带来了新的困难,针对实际的工程需求,创新性地将主流方法进行结合,提出了多Marker和ORB-SLAM混合跟踪的方法。通过二次调整多Marker定位结果的动态权值,提高局部定位维修的精度和可靠性。分析比较现有的特征点算法,选择ORB-SLAM作为方案,实现全局的定位和导航,对维修过程给以指导,并设计开发装备诱导维修系统,为大型复杂设备地维修提供了通用解决方案。     

齿轮齿条爬升式升船机驱动系统运行可靠性分析

针对升船机运行可靠性问题,以齿轮齿条爬升式升船机驱动系统为研究对象,根据可靠性理论,在统计驱动系统运行维护数据的基础上,综合分析停机故障次数和故障检修停航时间对运行可靠性的影响,计算得出驱动系统及其部件的运行可靠度,提出提高驱动系统运行可靠性的建议:应高度重视驱动齿轮托架机构、电气传动设备、传感检测装置等机电设备的维护检修和优化完善,充分考虑设备检修的便利性;基于停机故障次数和故障检修停航时间的运行可靠度计算分析方法,能准确反映升船机的运行可靠性。     

船舶自动化电站模拟器系统

阐述了最新研制开发的船舶自动化电站模拟器主要组成及功能原理。其基本功能是:操作控制的模拟功能,机组的安全保护功能,电站、拖动系统仿真功能,教学考评功能,与整个轮机模拟器联网的扩展功能。电站监控系统具有配电屏面监视、机舱监控、电力系统实时监视及控制4部分功能,并有运行参数动态监视,报警的记录及打印功能。     

龙溪口航电枢纽防护区运行安全智能管控系统研究

针对传统防护区运行安全管理以人工为主、信息利用低、动态评估预警缺失等问题，结合龙溪口航电枢纽防护区运行安全管理的主要问题和需求，以创新运行管理模式、强化信息互联共享、提升智能管控水平为目标，构建集数据在线辨识、涝情监控预测、安全实时诊断、风险动态评估、预警响应决策于一体的多层次系统结构，提出涝情实时监控、涝情风险评估、防洪堤安全分析与风险评估等核心功能模块的实现路径和技术要求。研究成果可为全面提升龙溪口航电枢纽防护区防灾减灾能力和安全保障水平提供技术支撑。     

防波堤及护岸越浪研究综述

近年来防波堤越浪方面的相关研究,分别在越浪影响因素、越浪量计算公式推导论证、越浪数值模拟与越浪量标准4个方面进行归纳总结.已有成果表明:1)越浪影响因素的研究多是集中于常规因素,包括波高周期,堤顶高程,坡肩宽度,护面块体,而对水流、风速、波浪谱以及水的性质等其他因素研究相对较少;2)越浪量计算公式研究中主要集中在影响越...     

多因素数学模型在温州瓯江口浅滩围涂工程研究中的应用

建立了波浪、潮流、盐度、悬沙、底床冲淤等多种因素数学模型,在模型验证的基础上,对瓯江口温州浅滩围涂工程海区的波浪场、潮流场、盐度场、悬沙场、底床冲淤场进行了数值模拟研究,对温州浅滩围涂工程对瓯江泄洪、瓯江南北口分流比、乐清湾养殖业、瓯江口港口航道及状元岙深水区、南口口外滩地的影响进行了分析论证。分析研究结果表明,温州浅滩围涂工程是可行的。     

How much can public private partnership really do for urban transport in developing countries?

A few cities in some of the larger developing countries in Latin America and Asia have made increasing use of multi-year concessions or franchises, competitively awarded to private companies, for construction and operation of urban transport infrastructure and for provision of public transport services. In view of the strong prospective growth of developing-country cities with large transport needs, and the rise in the emerging economies of potential new sources of private capital, it is important to see how effective PPP has so far been in this area. The experience is analyzed principally by thorough comparative review of what has actually happened for some of the main users to date: Bogotá, Santiago, São Paulo, Seoul, and several cities in both China and India. Despite delays and mistakes that have been made in development of most of the projects, the overall results, already delivered and in prospect, are very positive and urban public transport is benefiting substantially, with significant side effects on poorer people's access to work and to services, air pollution levels and road accident rates. The widest and most important advantage of the PPP arrangements, as compared with more conventional short-term contracting, is found to be the innovations, technical and managerial, developed, and, in particular, the mutual capacity building of the countries' private and public sectors and their more effective interaction. The experience in the six countries covered suggests that other developing-country cities may be best assisted to develop sound urban transport PPPs more rapidly through provision of help on chosen items among 7 elements that have proved particularly crucial but sometimes weak in the projects reviewed: Civic consultation systems, Land-use/Transport strategic planning, Land/property market management, Monitoring systems, Progressive policies, Economic regulation, and Public institutional framework for PPPs.