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1.
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   

2.
随着现代科学信息技术迅猛发展和广泛应用,我国测绘业已基本实现由传统模拟测绘技术体系向数字化、信息化测绘技术体系的跨越.地理信息是一种以采集、贮存、管理、分析和描述整个或部分地球表面空间地理分布有关数据的空间信息,已广泛应用于交通、电力、水利、农林、国土资源、环境保护、金融、电信、地质、矿产、城市建设、教育、人口、海洋以及军事等几十个领域.  相似文献   

3.
《机电设备》2007,24(3):I0007-I0007
法国船级社(BV)收购德国劳氏船级社(GL)已落下帷幕,收购失败.BV首席执行官曾强调,GL如果与BV合并,两大船级社将在世界各大船级社等机构中占据领先地位,这一地位在亚洲显得至关重要,大量投资将流向亚洲尤其是中国,以满足快速发展的船舶业市场.但是,GL汉堡总部对提高地位这一说法并不信服,因为自1994以来,GL已经在中国取得了稳固的市场地位,现在中国有50多家船厂已经拿到了超过350艘集装箱船、多功能船、散货船、油轮和化学品船的订单,而客户们信赖GL的质量保证、快速批准计划和可靠的技术支持.  相似文献   

4.
2008年4月3日上午。南通中远川崎船舶舾装码头彩旗飘扬,人头攒动,锣鼓喧天。全国政协副主席李金华、政协常委高俊良,交通运输部副部长徐祖远,江苏省副省长张卫国,中远集团总裁魏家福、党组书记张富生等集团领导,日本川崎重工株式会社副社长寺崎正俊以及南通市有关领导.日本川崎重工、中远造船工业公司和业界代表一百余人共同见证了中国首制1万标箱集装箱船——中远大洋洲轮命名交付仪式。  相似文献   

5.
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   

6.
耀思 《中国水运》2008,(4):12-14
党的十七大文件中第一次提到国家软实力问题。完成中华民族的伟大复兴,在于综合国力的全面提升,而综合国力既包括由经济、科技、军事实力等表现出来的“硬实力”,也包括以文化、意识形态吸引力体现出来的“软实力”。行业软实力是指一个行业以其自身的地位、作用和形象对社会产生的影响力、对公众产生的吸引力和对其他行业产生的仿效力。概括地讲,行业“软实力”包括三个要素,即理念先导力、精神感召力和舆论引导力,其中理念是先导,精神是动力,舆论是环境。  相似文献   

7.
公元前200多年,中国历史上演了有名的一幕:楚汉之争. 当时的情况是楚强汉弱,汉王刘邦连连吃败仗.可是刘邦是块牛皮糖、是个不倒翁,败了就逃,逃了又兜个圈子转回来,再打.楚王项羽受不了,对刘邦说:"不如我们一对一单挑,决个雌雄罢,免得天下百姓再为你我二人白白受苦了!"(愿与王独身挑战,以决雌雄,毋徒令天下父子为也.)刘邦笑了笑,答道:"吾宁斗智,不愿斗力."结果,力能拔山、气可盖世的楚霸王项羽,就这样慢慢被刘邦"耗"死了--流氓出身的刘邦成了汉高祖.  相似文献   

8.
The progress of economic globalization,the rapid growth of international trade,and the maritime transportation has played an increasingly significant role in the international supply chain.As a result,worldwide seaports have suffered from a central problem,which appears in the form of massive amounts of fuel consumed and exhaust gas fumes emitted from the ships while berthed.Many ports have taken the necessary precautions to overcome this problem,while others still suffer due to the presence of technical and financial constraints.In this paper,the barriers,interconnection standards,rules,regulations,power sources,and economic and environmental analysis related to ships,shore-side power were studied in efforts to find a solution to overcome his problem.As a case study,this paper investigates the practicability,costs and benefits of switching from onboard ship auxiliary engines to shore-side power connection for high-speed crafts called Alkahera while berthed at the port of Safaga,Egypt.The results provide the national electricity grid concept as the best economical selection with 49.03 percent of annual cost saving.Moreover,environmentally,it could achieve an annual reduction in exhaust gas emissions of CO2,CO,NOx,P.M,and SO2by 276,2.32,18.87,0.825 and 3.84 tons,respectively.  相似文献   

9.
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   

10.
As a novel type of foundation in beach and shallow sea,the bucket structure is especially suitable for complex conditionssuch as soft clay ground and the worse types of sea environments.In this paper, the bearing capacity of a multi-bucket structure isstudied by experiments with a single bucket and four-bucketfoundation in a saturated sand layer. Based on the experimentaldata and numerical analysis results, the bearing capacity behaviorand the bucket group effect are compared and analyzed.Furthermore, some influential factors, such as the soil type, theratio of length to diameter L/D, the ratio of the bucket spacing tothe bucket diameter S/D, and the bucket number are introduced andtheir effects on the multi-bucket structural capacity are investigatedThe vertical static capacity adjustment factor is introduced toevaluate the bucket group effects of the multi-bucket foundation.  相似文献   

11.
基于第3代数值海浪模型SWAN,采用自嵌套的方法提供谱型边界,对渤海"98.04"寒潮大风引起的风浪过程进行了数值模拟研究。将数值模拟结果与T/P卫星高度计观测资料和近岸浮标实测资料(波高和波向)进行了较为详细的比较,并分析了风浪要素的时空分布。结果显示风浪要素的模拟值与实测值吻合良好,表明SWAN模型能较好地再现渤海寒潮期间风浪的时空分布。  相似文献   

12.
海面粗糙度对于海洋工程、海气相互作用和军事海洋研究来讲非常重要,但由于海面粗糙度难以直接测量,因此只能通过间接计算得到。随着卫星微波遥感技术的发展,卫星高度计、散射计等为研究海面粗糙度提供了新的研究方法和研究渠道。作者利用T/P星1997-2000年的高度计反演得出的海面风场数据实现了对海面粗糙度的反演,并对太平洋海域(15°-30°N,135°-150°E)海面粗糙度进行研究,同时研究发现太平洋海面粗糙度在El-Nino、La-Nina期间有明显变化。  相似文献   

13.
An altimeter data assimilation scheme has been tested in the OCCAM (Ocean Circulation and Climate Advanced Modelling) global 1/4°, 36-level model using a twin experiment format. The Cooper and Haines displacement scheme is used. The method works well in most regions and depths. Currents and densities in the top 1000 m generally improve by over 50–70% after 5 months of sea level assimilation every 15 days. Below 1000 m, an error reduction of up to 50% is achieved. The errors remain low during a further 60-day run without assimilation. Diagnostics for the North Atlantic, the Tropical Pacific and the Antarctic Circumpolar Current are shown alongside the global averages.The main problems encountered were in weakly stratified regions of the Antarctic and Arctic seas. A scale selective filter is developed to avoid assimilating scales much larger than the local deformation radius, and this avoids the adverse assimilation effects in the southern oceans. A companion paper uses this scheme to assimilate TOPEX and ERS-1 altimeter maps.  相似文献   

14.
利用卫星微波遥感资料推算波浪极值   总被引:11,自引:0,他引:11  
应用已取得的T/P卫星高度计资料和ERS-1卫星散射记资料,计算和推算结果表明,推算的极值与实测的极值非常接近,差值小于0.4m。利用卫星微波遥感资料推算多年一遇的波高极值,方案是可行的,方法是可靠的,精度是可信的。  相似文献   

15.
The quality of numerical wave forecasts can be improved significantly by assimilating wave observations prior to the forecast. In the present study a technique for such assimilation is developed that exploits (a) the efficiency of a limited number of integral control variables, and (b) the effectiveness of variational (model-consistent) assimilation. The formal procedure is independent of the type of control variables and of the wave model (moreover, no adjoint wave model is required). In the present study, integral control variables are chosen to represent large-scale errors in the driving wind fields and uncertainties in the wave model. The assimilation technique is validated with observations of the ERS-1 satellite altimeter and two waverider buoys in two consecutive storms in the Norwegian Sea. The assimilation of the observations reduced the errors in the forecasted significant wave height at the buoy locations typically from 25% to 12%. For low-frequency waves the effect of the assimilation is similarly significant at one buoy location but marginal at the other buoy location.  相似文献   

16.
A simulation of the movement of spilled oil after the incident of the Russian tanker Nakhodka in the Sea of Japan, in January 1997, was performed by a particle tracking model incorporating advection by currents, random diffusion, the buoyancy effect, the parameterization of oil evaporation, biodegradation, and beaching. The currents advecting spilled oil were defined by surface wind drift superposed on the three-dimensional ocean currents obtained by the Geophysical Fluid Dynamics Laboratory modular ocean model (GFDL MOM), which was forced by the climatological monthly mean meteorological data, or by the European Center for Medium Range Weather Forecasts (ECMWF) daily meteorological data, and assimilated sea surface topography detected by satellite altimeter. A number of experiments with different parameters and situations showed that the wide geographical spread of oil observed is not explained by wind drift alone, and that including the simulated climatological currents gives better results. The combination of surface wind drift and daily ocean currents shows the best agreement between the model and observations except in some coastal areas. The daily meteorological effect on the ocean circulation model results in a stronger variability of currents that closely simulates some features of the nonlinear large-scale horizontal turbulent diffusion of oil. The effect of different parameterizations for the size distribution of model oil particles is discussed. Received for publication on July 26, 1999; accepted on Nov. 17, 1999  相似文献   

17.
A 1/32° global ocean nowcast/forecast system has been developed by the Naval Research Laboratory at the Stennis Space Center. It started running at the Naval Oceanographic Office in near real-time on 1 Nov. 2003 and has been running daily in real-time since 1 Mar. 2005. It became an operational system on 6 March 2006, replacing the existing 1/16° system which ceased operation on 12 March 2006. Both systems use the NRL Layered Ocean Model (NLOM) with assimilation of sea surface height from satellite altimeters and sea surface temperature from multi-channel satellite infrared radiometers. Real-time and archived results are available online at http://www.ocean.nrlssc.navy.mil/global_nlom. The 1/32° system has improvements over the earlier system that can be grouped into two categories: (1) better resolution and representation of dynamical processes and (2) design modifications. The design modifications are the result of accrued knowledge since the development of the earlier 1/16° system. The improved horizontal resolution of the 1/32° system has significant dynamical benefits which increase the ability of the model to accurately nowcast and skillfully forecast. At the finer resolution, current pathways and their transports become more accurate, the sea surface height (SSH) variability increases and becomes more realistic and even the global ocean circulation experiences some changes (including inter-basin exchange). These improvements make the 1/32° system a better dynamical interpolator of assimilated satellite altimeter track data, using a one-day model forecast as the first guess. The result is quantitatively more accurate nowcasts, as is illustrated by several model-data comparisons. Based on comparisons with ocean color imagery in the northwestern Arabian Sea and the Gulf of Oman, the 1/32° system has even demonstrated the ability to map small eddies, 25–75 km in diameter, with 70% reliability and a median eddy center location error of 22.5 km, a surprising and unanticipated result from assimilation of altimeter track data. For all of the eddies (50% small eddies), the reliability was 80% and the median eddy center location error was 29 km. The 1/32° system also exhibits improved forecast skill in relation to the 1/16° system. This is due to (a) a more accurate initial condition for the forecast and (b) better resolution and representation of critical dynamical processes (such as upper ocean – topographic coupling via mesoscale flow instabilities) which allow the model to more accurately evolve these features in time while running in forecast mode (forecast atmospheric forcing for the first 5 days, then gradually reverting toward climatology for the remainder of the 30-day forecast period). At 1/32° resolution, forecast SSH generally compares better with unassimilated observations and the anomaly correlation of the forecast SSH exceeds that from persistence by a larger amount than found in the 1/16° system.  相似文献   

18.
我国应用星载基站AIS系统研究   总被引:2,自引:0,他引:2  
杨倩 《中国海事》2011,(1):53-55
文中从分析我国海上运输的发展趋势及现有的监管技术存在的问题出发,结合国外的经验,提出了运用星载基站AIS技术来解决远海海域船舶的监管问题,并在此基础上阐述了星载基站AIS的优势及我国发展星载基站AIS的意义,最后提出了我国实现星载基站AIS应用的两种方案。  相似文献   

19.
本文提出了大卫星定位通信系统中采用四相扩频(Q-SS)技术,并沿用瑞士人给出的卫星转发器功率放大器的数学模型,推导了Q-SS信号通过卫星转发器后输出的表示式;通过进一步分析发现了采用Q-SS技术可以在信号解扩后完全消除三阶和五阶的互调干扰。  相似文献   

20.
简述了导航定位技术的发展过程以及几种主要的卫星导航定位系统。论述了卫星导航定位系统在现代军事上的应用及导航战的含义。最后,对导航战背景下的卫星导航定位技术所面临的挑战和应对措施进行了讨论。  相似文献   

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