冰盖下两层流体水波与可渗透起伏海床的作用(英文)

The scattering problem involving water waves by small undulation on the porous ocean-bed in a two-layer fluid,is investigated within the framework of the two-dimensional linear water wave theory where the upper layer is covered by a thin uniform sheet of ice modeled as a thin elastic plate.In such a two-layer fluid there exist waves with two different modes,one with a lower wave number propagate along the ice-cover whilst those with a higher wave number propagate along the interface.An incident wave of a particular wave number gets reflected and transmitted over the bottom undulation into waves of both modes.Perturbation analysis in conjunction with the Fourier transform technique is used to derive the first-order corrections of reflection and transmission coefficients for both the modes due to incident waves of two different modes.One special type of bottom topography is considered as an example to evaluate the related coefficients in detail.These coefficients are depicted in graphical forms to demonstrate the transformation of wave energy between the two modes and also to illustrate the effects of the ice sheet and the porosity of the undulating bed.     

厦门港叫板高雄港

近年来，受各种因素的影响，海峡东岸高雄港的国际集装箱中转港和世界大港地位受到挑战，尤其是来自西岸厦门港的威胁。本文从高雄和厦门两港的地理位置出发，对两港的港航条件、外部环境和吞吐量格局进行了比较分析。     

以科学发展观为指导打造长江黄金水道

学习贯彻十七大精神，对于动员拿党全国各族人民，存以胡锦涛同忠为总书记的党中央坚强领导下，高举中国特色社会主义伟大旗帜，奋力夺取全面建没小埭社会新胜利、圩创中国特色礼会主义事业新局而，具有重大现实意义和深远历史意义。长汀航道各级党组织要把组织学习和贯彻落实十七大精神作为当前和今后一个时期的首要政治任务，迅速把干部职工的思想和行动统一到全会精神上来，     

散货集装箱化的成因及发展趋势

0引言近年来全球集装箱运量的年增长率基本维持在10%以上,据初步统计2007年全球集装箱运量达1.3亿TEU,港口吞吐量达4.7亿TEU。随着集装箱制造、装卸工艺的改进,适箱货物的范围也在不断扩大。20世纪90年代,美国就开始采用集装箱运     

打造民族知名品牌的三一港口机械——访三一港口机械公司彭国成总经理

<正>众所周知,三一重工股份有限公司是一家享有盛誉的上市公司,曾连续4年上榜中国最具价值品牌,是工程机械行业内的标志性企业之一。作为中国最具科研实力的工程机械制造商,三一重工拥有国家级技术中心、博士后工作站,并承接有国家863课题,取得专利400多项。三一重     

2007IEEE机电一体化与自动化国际会议开幕

由国家自然科学基金、王宽诚基金、美国电气电子工程师学会(IEEE)和日本香川大学等资助,哈尔滨工程大学承办的"2007IEEE机电一体化及自动化国际会议"8月6日在哈尔滨市香格里拉饭店开幕.来自中、美、日、韩、加等27个国家和地区的500余名代表出席会议,其中有近200名国外代表,国防科工委副主任金壮龙,黑龙江省委常委、省科技厅厅长孙尧出席大会并致辞.会议共收到来自33个国家和地区的投稿论文1861篇.经过国内外专家的严格审阅和定稿,最终录用701篇,采用率不到37%.     

海一鸥游艇公司携日本洋马公司共拓中国市场

海一鸥游艇有限公司是代理销售国外知名船艇并提供相关服务及设施的专营公司.海一鸥游艇有限公司注册于上海,分别在北京、大连、青岛、深圳设有分公司,在广州设有分销商.     

科学家发现红海正在裂变

美国、英国、埃塞俄比亚等多国科学家目前透露,位于非洲东北部与阿拉伯半岛之间的红海正在发生分裂,数百万年之后可能将产生一个新的海洋,而非洲大陆也将分成两部分.这个研究成果证实了目前普遍认同的大陆板块构造学说.     

青春无悔——记中远集团十大杰出青年杨成才

杨成才，从大学毕业分配至中波轮船股份公司，仅用短短7年时间就成长为中波公司最年轻的优秀轮机长。扎实深厚的理论功底，刻苦钻研的探索精神，踏实肯干的工作作风以及对远洋运输事业的热爱与执着，是他快速脱颖而出的源泉。他曾先后荣获全国交通系统青年岗位能手，中央企业知识型先进职工，第三届中远集团十大杰出青年等荣誉称号。     

军工科技档案保密工作存在问题及对策

军工科技档案是武器装备研制单位在从事军工科技活动中形成的原始记录,是重要的国家和国防科技财富,是军队列装技术和国防储备技术的重要信息源.做好军工科技档案保密工作事关党和国家的根本利益,事关军队的安危,事关军工科技事业发展的全局,我们一定要从政治和战略的高度,充分认识此项工作的极端重要性.     

航海风险识别、评估和控制

因航运业高速发展和海员职业流动性加快,导致全球高级船员紧缺,已引发高级船员提升周期缩短、航海经验不足等现象。航海事故造成人员伤亡、财产损失和污染海洋环境等已严重威胁公共安全,航海事故预防和风险控制越来越受到人们关注。船舶海上事故频发,与船员对海上风险,尤其是船员对人为因素与事故的关系的认识不足有关。通过重点介绍航海风险,提高船员对本船和自身存在的风险意识,采取相应的防范措施。     

现代工程测量技术发展浅谈

电子计算机技术、微电子技术、激光技术、空间技术等新技术的发展与应用,以及测绘科学技术的进步,为工程测量技术进步提供新的方法和手段.阐述现代工程测量仪器的发展状况,介绍与展望地面测量仪器和CPS定位等空间技术在工程测量中的应用和发展.     

Characteristics of low-frequency motions of ships moored inside ports and harbors on the basis of field observations

In order to understand characteristics of low-frequency motions of ships moored inside ports and harbors, analysis on actual cargo handling logbook of stevedoring services company, including events of interruption of cargo handling, and countermeasure for ship mooring problems are investigated by field observations at two ports and numerical simulation on moored ship motions. First model port concerns with interruption of cargo handling due to the low-frequency motions. Second model port relates to a resonant effect of long-period waves or harbor oscillations, and its countermeasure by mooring system. From the investigation, it is confirmed that the low-frequency motions of ships are induced by a resonance between surge motions and long-period waves or harbor oscillations and an asymmetry in the mooring system, and affect safe ship mooring and operation efficiency of cargo handling in ports and harbors significantly.     

桥梁防撞设施物理模型试验

物理模型试验是预报防撞设施所受撞击力及优化设计方案的主要方法之一。结合杭州湾大桥柔性防撞设施及东海大桥独立式防撞体设计方案,阐述了船—防撞体撞击试验的基本原理、方法、试验方案及相关试验结果。提出了柔性防撞系统的优化方案。试验结果表明,该方案经济有效,可供预报类似桥梁防撞设施撞击力时参考。     

船用五螺杆泵低噪声工艺技术

本文通过对现有的某船用五螺杆泵的频谱特征和振动特性进行分析,找出主要振动噪声源,通过改进进口流道面积,并对现有的螺杆加工工艺进行研究和优化改进,改进后的设计通过样机的制造,并经过试验对比分析,进一步验证方法的可行性和预期减振效果。     

基于字节流数据包的舰船控制系统数据交互技术

本文结合舰船机电控制系统特点和测控技术领域PLC和Labview两者优点,基于字节流数据包的数据灵活性,设计PLC和Labview通信数据包模型,并遵循模块化程序设计原则完成通信接口程序设计,解决舰船机电系统集中控制器和人机接口数据交互的描述问题和通信接口程序通用性问题。最后,通过实例验证设计的数据包模型和通信接口程序能够实现数据快速可靠安全的交互。该技术可应用于舰船综合监控系统和类似系统的软件开发。     

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.     

Collaborative Integrated Management in Canada's North: The Role of Local and Traditional Knowledge and Community-Based Monitoring

The objective of this article is to take stock of integrated management in the Canadian North, assessing its contribution to the advancement of knowledge and practice regarding the role of indigenous knowledge and community-based monitoring. This is done in three steps. (1) The Beaufort Sea, designated a Large Ocean Management Area under Canada's Oceans Action Plan, is used as an example of a consultative planning process, with special attention to indigenous peoples. (2) How specifically can indigenous knowledge contribute to integrated management? The problem of Arctic marine food web contamination is used to illustrate the strengths and limitations of traditional ecological knowledge and its relationship to science. (3) The discussion of community-based monitoring relies on Voices From The Bay study involving the Inuit and Cree of Hudson and James Bay, and Inuit observations of climate change study in the Canadian western Arctic. The examples together address integrated coastal management and the health of ocean ecosystems, showing how stakeholder participation and knowledge helps widen the range of knowledge to understand and help monitor environmental change.     

BIM技术在航道建设中的作用

航道工程具有施工工期长、施工影响因素多等特点。在航道工程的设计、施工、维护的各个阶段,随着对精细化管理的需求日趋提高,传统的实施方法已不能满足工程的强度与精度要求。从航道工程和BIM的特性入手,探讨了BIM技术在航道工程设计、施工、维护等各阶段的应用。在保证设计合理性的前提下,可通过BIM模型完成设计意图的表达与传递,从而保证航道工程的施工质量,以及后续维护阶段航道整治建筑物安全、稳定地发挥其作用。     

Towards a seascape typology. I. Zipf versus Pareto laws

Two data analysis methods, referred to as the Zipf and Pareto methods, initially introduced in economics and linguistics two centuries ago and subsequently used in a wide range of fields (word frequency in languages and literature, human demographics, finance, city formation, genomics and physics), are described and proposed here as a potential tool to classify space–time patterns in marine ecology. The aim of this paper is, first, to present the theoretical bases of Zipf and Pareto laws, and to demonstrate that they are strictly equivalent. In that way, we provide a one-to-one correspondence between their characteristic exponents and argue that the choice of technique is a matter of convenience. Second, we argue that the appeal of this technique is that it is assumption-free for the distribution of the data and regularity of sampling interval, as well as being extremely easy to implement. Finally, in order to allow marine ecologists to identify and classify any structure in their data sets, we provide a step by step overview of the characteristic shapes expected for Zipf's law for the cases of randomness, power law behavior, power law behavior contaminated by internal and external noise, and competing power laws illustrated on the basis of typical ecological situations such as mixing processes involving non-interacting and interacting species, phytoplankton growth processes and differential grazing by zooplankton.