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1.
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.  相似文献   

2.
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。  相似文献   

3.
《机电设备》2007,24(8):I0005-I0005
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%.  相似文献   

4.
《机电设备》2007,24(4):I0010-I0011
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.  相似文献   

5.
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,  相似文献   

6.
张成  袁兵 《集装箱化》2008,19(2):24-27
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  相似文献   

7.
<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  相似文献   

8.
美国海岸警备队港口长官(COTP)或口岸当局(OCMI)对存在缺陷的船舶,根据缺陷的严重性,决定对这些船舶采取控制行动来保证船舶、港口和环境的安全,至于控制的程度、范围以及当局的执行力则和这些缺陷的本性一致.  相似文献   

9.
Global strength is a significant item for floatingproduction storage and offloading (FPSO) design, and steel weightplays an important role in the building costs of FPSO. It is the maintask to consider and combine these two aspects by optimizing hulldimensions. There are many optional methods for the globalstrength analysis. A common method is to use the ABS FPSOEagle software to analyze the global strength including the rulecheck and direct strength analysis. And the same method can beadopted for the FPSO hull optimization by changing the depth.After calculation and optimization, the results are compared andanalyzed. The results can be used as a reference for the futuredesign or quotation purpose.  相似文献   

10.
重力式码头工程的预制构件一般重量较大,在批量大、规格多的情况下,选择何种搬运工艺,涉及场地布置、设备选用、施工操作人员的劳动强度、搬运效率和经济合理等一系列问题.采用2台轨道电动平车组合搬运3000~5000kN方块的工艺,为重力式码头的构件搬运开辟了新的途径,在港口水工建筑施工中具有广阔的应用前景.  相似文献   

11.
在以VAXlab计算机为主机的小型通用动力学半实物仿真系统上对某型水下航行器的运动进行了半实物仿真。给出了半实物仿真系统的基本组成和工作原理,讨论了水下航行器运动的仿真模型和实时积分算法。结果表明,该仿真系统结构合理,精度高,可靠性好,所采用的控制方案可使其满足使用要求,达到了预期的目的。  相似文献   

12.
This paper examines the stereotypic image of the American merchant seaman. The persistence of this stigma has made attempts at higher social status for seamen problematic. A typology of seamen is constructed on the basis of two dimensions: primary identification either with seaman subculture or shore-side society; and response to the stigma of the occupation. Ninety-five interviews were conducted with seamen, union officials, and relatives of seamen. Participant observation is used to supplement the data obtained in the interviews.  相似文献   

13.
国新 《中国船检》2007,(2):42-44
最近,国家发改委和长江三峡通航管理局多次发出通告,强调在整个完建期内,煤炭船凭证过闸政策不变,沿江航运企业煤炭运输船舶通过三峡船闸,仍需有国家发改委颁发的通行证。但是上有政策,下有对策,这个明显带有计划经济影子的票证制度,在无所畏惧的21世纪的川江船户中遭到了多种方式的化解。作为三峡工程全部完成前的一个必经阶段,完建期内过闸需暂时性的单线运行,需要相关管理部门和企业都能以最大的合作精神,顽强地挺过这段艰难时期。  相似文献   

14.
Traditional liner carriers, operating in the highly competitive commercial environment of the last few years, have attempted to lower the marginal cost of each box carried. Technological improvements in both construction and propulsion systems have led to a steady growth in carrying capacity. Ships of 600+ TEUs are now in service and, as a result of this trend, have displaced 'smaller' ships from the major east-west trades. The more competitive environment of these trades has in turn led to a redeployment of ships in the 2500+ TEU range to the north-south trades. The result has been a rapid increase in north-south capacity, including feeder services and falling freight rates. Despite the current excess supply in shipping and historically low freight rates, significant developments in technology have created opportunities for new fast containerships. The paper analyses the key economic factors in the differentiation of the new fast ship technology from the traditionally designed containerships and demonstrates the potential financial viability to owners of these new 'greyhounds'.  相似文献   

15.
钹式水听器体积小,灵敏度高,但其接收性能不够稳定,接收频带较窄.为了克服这些弱点,对其结构进行改进.运用双片陶瓷并联代替单片陶瓷,并缩小陶瓷半径.再通过有限元仿真实验和水池实验,对改进前后的钹式水听器进行测试,结果表明,改进后的钹式水听器接收性能更加稳定,接收频带也明显增加,同时其灵敏度依然较高.  相似文献   

16.
This paper examines one sector of the economy of an LDC, namely, port investment and planning, and considers the ways in which some of the arguments concerning choice of technology in LDCs apply to this sector.  相似文献   

17.
该文介绍了无人潜器UUV(UnmannedUnderwaterVehicle)光学引导回收技术方面最新的研究结果 ,提出了回收过程的光学引导系统的模型 ,给出了不同光源配置条件下的光学引导系统仿真结果及其精确性和可靠性。这些仿真结果也可以帮助建立一个光学引导和控制模式。  相似文献   

18.
本轮国际金融危机和全球经济增长明显放缓给我国水运业带来了重大影响,肮运形势急转直下,航运业进入低迷期。今年是我国水运行业应对危机、克服难关的关键一年。  相似文献   

19.
NIR不期而至     
对于很多人来说,NIR仍然是一个比较陌生的术语。何为NIR?NIR即New Inspection Regime,是于2011年1月1日起正式运行的巴黎备忘录新的PSC检查机制。  相似文献   

20.
This paper examines one sector of the economy of an LDC, namely, port investment and planning, and considers the ways in which some of the arguments concerning choice of technology in LDCs apply to this sector.  相似文献   

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