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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
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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
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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
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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
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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
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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
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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
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京杭运河是我131南北向水上运输尤其是煤炭运输的大动脉,同时也承担了南水北调输水主干线的重任,具有极其重要的战略地位.微山船闸作为京杭运河Ⅱ级坝上唯一的通航枢纽,承担着京杭运河过Ⅱ级坝的所有货物运输量.为促进区域经济发展,保持京杭运河航运的畅通,充分发挥京杭运河国家水运主通道的作用,彻底消除安全隐患,从工程、环境、经济等角度探讨微山船闸的改扩建模式. 相似文献
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有限水深中垂直下潜弹性薄板的水波散射(英文) 总被引:1,自引:0,他引:1
The problem of water wave scattering by a thin vertical elastic plate submerged in uniform finite depth water is investigated here.The boundary condition on the elastic plate is derived from the Bernoulli-Euler equation of motion satisfied by the plate.Using the Green’s function technique,from this boundary condition,the normal velocity of the plate is expressed in terms of the difference between the velocity potentials(unknown)across the plate.The two ends of the plate are either clamped or free.The reflection and transmission coefficients are obtained in terms of the integrals’involving combinations of the unknown velocity potential on the two sides of the plate,which satisfy three simultaneous integral equations and are solved numerically.These coefficients are computed numerically for various values of different parameters and depicted graphically against the wave number in a number of figures. 相似文献
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CFD simulation of propeller and rudder performance when using additional thrust fins 总被引:2,自引:0,他引:2
HUANG Sheng ZHU Xiang-yuan GUO Chun-yu CHANG Xin 《船舶与海洋工程学报》2007,6(4):27-31
To analyse a possible way to improve the propulsion performance of ships,the unstructured grid and the Reynolds Average Navier-Stokes equations were used to calculate the performance of a propeller and rudder fitted with additional thrust fins in the viscous flow field.The computational fluid dynamics software FLUENT was used to simulate the thrust and torque coefficient as a function of the advance coefficient of propeller and the thrust efficiency of additional thrust fins. The pressure and velocity flow behind the propeller was calculated. The geometrical nodes of the propeller were constituted by FORTRAN program and the NUMBS method was used to create a configuration of the propeller,which was then used by GAMMBIT to generate the calculation model. The thrust efficiency of fins was calculated as a function of the number of additional fins and the attack angles. The results of the calculations agree fairly well with experimental data,which shows that the viscous flow solution we present is useful in simulating the performance of propellers and rudders with additional fins. 相似文献
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基于滑移网格技术计算螺旋桨水动力性能研究 总被引:2,自引:0,他引:2
基于RANS方程的CFD软件数值模拟螺旋桨定常和非定常的水动力性能.定常计算采用多重参考系MRF模型,分别采用标准k-ε的湍流模型,RNG k-ε湍流模型和Reliable k-ε湍流模型模拟在不同进速系数时的推力系数和转矩系数.将模拟的数值结果与试验值相比较,计算结果表明,采用Reliable k-ε湍流模型计算出的推力系数与转矩系数与试验值基本吻合,并以该结果为初始场,通过滑移网格技术,采用单机并行计算螺旋桨非定常水动力性能.相较于定常计算结果更加接近试验值,说明滑移网格技术具有更高的精准度,更加适用于计算螺旋桨的水动力性能. 相似文献
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为研究鳍的影响,建立了吊舱推进器的水动力性能的计算模型.计算了吊舱推进器安装和不安装鳍时的水动力性能,螺旋桨与吊舱及鳍之间的相互影响通过迭代计算加以考虑.采用基于速度势的基本积分微分方程,并采用双曲面元以消除面元间的间隙.采用Newton-Raphson迭代求解压力分布使得桨叶的随边满足压力库塔条件,用柳泽的方法求得物体表面的速度分布以避免数值求导的奇异性.无鳍.单鳍和双鳍的吊舱推进器水动力性能计算结果表明,附加鳍时吊舱推进器的螺旋桨推力增加,由于鳍上产生推力导致吊舱阻力减小.附加双鳍时的吊舱推进器水动力性能最好,附加单鳍时次之,无鳍时最低. 相似文献
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采用滑移网格技术,使用基于求解RANS方程的CFD软件数值模拟均匀流场中的螺旋桨非定常水动力性能.为了真正实现螺旋桨的旋转运动,在计算过程中采用定长多运动参考系模型计算出初始流场,再用滑移网格模型完成整个计算.数值计算得到的推力系数和转矩系数与实验结果吻合良好,验证了该方法应用于螺旋桨水动力性能研究的可行性. 相似文献
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CFD理论黏性流场中三维振动水翼的非定常水动力性能(英文) 总被引:1,自引:0,他引:1
The motion of the fins and control surfaces of underwater vehicles in a fluid is an interesting and challenging research subject.
Typically the effect of fin oscillations on the fluid flow around such a body is highly unsteady, generating vortices and
requiring detailed analysis of fluid-structure interactions. An understanding of the complexities of such flows is of interest
to engineers developing vehicles capable of high dynamic performance in their propulsion and maneuvering. In the present study,
a CFD based RANS simulation of a 3-D fin body moving in a viscous fluid was developed. It investigated hydrodynamic performance
by evaluating the hydrodynamic coefficients (lift, drag and moment) at two different oscillating frequencies. A parametric
analysis of the factors that affect the hydrodynamic performance of the fin body was done, along with a comparison of results
from experiments. The results of the simulation were found in close agreement with experimental results and this validated
the simulation as an effective tool for evaluation of the unsteady hydrodynamic coefficients of 3-D fins. This work can be
further be used for analysis of the stability and maneuverability of fin actuated underwater vehicles. 相似文献
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为了研究特种推进器导管桨在非定常下的水动力性能,本文提出一种基于重叠网格的方法,实现了导管桨旋转过程中的非定常水动力性能仿真高精度模拟。本文通过求解RANS方程,采用湍流模型Realizableκ-ε,借助新款计算流体软件STARCCM+,应用重叠网格技术和MRF模型分别计算了导管桨在非定常与定常时的水动力性能,分析了压力流场细节,并与已有试验值进行对比,验证了采用重叠网格技术和STAR CCM+流体软件应用于导管桨非定常和定常水动力性能计算的可靠性。研究结果表明,应用重叠网格技术获得的非定常水动力性能的计算精度更高,尤其是在螺旋桨的推力和扭矩方面。 相似文献
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