仿鱼尾潜器推进系统的水动力分析   总被引：21，自引：3，他引：21  

苏玉民  黄胜等 《海洋工程》2002,20(2):54-59

以开发适用于小型潜器的仿生操纵与推进系统为研究背景 ,对金枪鱼的月牙形尾鳍进行水动力分析。文中将金枪鱼的尾鳍处理为在做横移和摇摆的耦合运动的同时 ,以某一匀速向前运动的月牙形刚性尾翼。计算中应用了双曲面元和压力库塔条件 ,利用面元法计算分析该三维尾翼的非定常水动力性能。探讨了前进速度、横荡和摇首的幅度、频率及其相位差对推进性能的影响  相似文献   

On the radiation and diffraction of linear water waves by an infinitely long rectangular structure submerged in oblique seas   总被引：1，自引：0，他引：1  

Y.H. Zheng  P.F. Liu  Y.M. Shen  B.J. Wu  S.W. Sheng 《Ocean Engineering》2007,34(3-4):436-450

The radiation and diffraction of linear water waves by an infinitely long rectangular structure submerged in oblique seas of finite depth is investigated. The analytical expressions for the radiated and diffracted potentials are derived as infinite series by use of the method of separation of variables. The unknown coefficients in the series are determined by the eigenfunction expansion matching method. The expressions for wave forces, hydrodynamic coefficients and reflection and transmission coefficients are given and verified by the boundary element method. Using the present analytical solution, the hydrodynamic influences of the angle of incidence, the submergence, the width and the thickness of the structure on the wave forces, hydrodynamic coefficients, and reflection and transmission coefficients are discussed in detail.  相似文献   

Current-influenced depositional provinces, continental margin off Cape Hatteras, identified by petrologic method     

Daniel Jean Stanley  Harrison Sheng  Douglas N. Lambert  Peter A. Rona  David W. McGrail  J.Stacy Jenkyns 《Marine Geology》1981,40(3-4):215-235

Analyses of DSRV “Alvin” core samples on the Cape Hatteras margin indicate major textural and compositional changes at depths of about 1000 and well below 2500 m. The distribution patterns of petrologic parameters correlate well with water mass flow and suspended-sediment plumes measured on this margin by other workers. Our study also shows: (a) vigorous erosion and sediment transport at depths of less than 400 m resulting from the NE-trending Gulf Stream flow; (b) deposition, largely planktonic-rich sediment released from the Gulf Stream, on the upper- to mid-slope, to depths of about 800–1200 m; (c) winnowing, resuspension and deposition induced by periodically intensified slope currents on the mid-slope to uppermost rise, between about 1000 and 2500 m; and (d) prevailing deposition on the upper rise proper (below 2500 m), from transport by the SW-trending Western Boundary Undercurrent. Sediments moved by bottom currents have altered the composition and distribution patterns of material transported downslope by offshelf spillover; this mixing of gravity-emplaced and bottom-current-transported sediment obscures depositional boundaries. Moreover, reworking of the seafloor by benthic organisms alters physical properties and changes erodability of surficial sediments by bottom currents. Measurement of current flow above the seafloor and direct observation of the bottom are insufficient to delineate surficial sediment boundaries. Detailed petrologic analyses are needed to recognize the long-term signature of processes and define depositional provinces.  相似文献   

6个虾种基因组DNA多态性分析   总被引：2，自引：0，他引：2  

许玉德  孙晟 《海洋科学》2001,25(1):9-11

采用RAPD方法检测了罗氏沼虾（Macrobrachium rosenbergii)、绿须虾（Aristeus virilis)、长毛对虾（Penaeus penicillatus)、日本对虾（P.japonicus)、斑节对虾（P.monodon)和周氏新对虾（Metapenaeus joyneri)等6个虾种的基因组DNA的多态性。用20个随机引物扩增得到492个DNA片段，根据这些片段的共享度计算出遗传距离并构建系统树。所得结果从DNA水平上反映出虾类在科属种不同分类阶元亲缘关系的远近，并为虾类现行的分类系统提供了分子生物学依据。  相似文献   

海上矿石运输最优船队的组建     

董胜 《中国海洋大学学报(自然科学版)》1997,(2)

针对海上矿石运输，介绍了一种完成定量任务并能使投资费用最少为目标的最优船队组建方法，同时对易变参数进行了灵敏度分析，使决策更加科学化  相似文献   

日本列岛东部海域发现未知海流     

苏方 《海洋信息》2001,(1)

日本海洋科学技术中心最近发表观测报告宣布,在日本列岛东部海域发现见了过去未曾观测到的强大海流。 报告说,这股海流的位置在流经日本列岛南部的暖流以北250公里处,由东向西,与暖流呈相反方向,流速达3.5节(1.852公里)每小时。据悉,这股暖流是科学家们于本月初通过观测浮标的位移而发现的。该中心认为这一发现颇有意义,并表示将进一步研究这股海流对渔业资源及二氧化碳吸收量等的影响。  相似文献   

I(L)值完全诱导空间     

方进明  岳跃利  刘刚 《中国海洋大学学报(自然科学版)》2001,31(6):960-964

作者引入 I(L)值完全下半连续映射 ,研究其性质。利用 I(L)值完全下半连续映射定义I(L)值完全诱导空间 ,给出 I(L)值完全诱导空间的拓扑基的表达形式 ,证得两个 I(L)值完全诱导空间的映射是连续映射的充分必要条件 ,并建立了乘积空间的 I(L)值完全诱导空间与 I(L)值完全诱导空间的乘积空间的联系  相似文献   

A new type of Shipboard Meteorological Satellite Receiving-processing System   总被引：1，自引：0，他引：1  

Xie Simei  Hao Chunjiang  Zou Bin  Jing Qiyi  Liao Xiaohong  Sheng Xiaowen  Zhang Canrong 《海洋学报(英文版)》2000,19(1):35-46

INTRODUCTIONTheSMSRPSisstalledontheshipnavigatingovertheseaandreceivessatellitecloudmapsatanytimetoprovidereliablereal-timedataofmeteorologyandocean.Itisanimportantequipmentforsafeguardofshipnavigation.Chinahasthousandsofoceanicships.Butalmostallships,withonlyveryfewexception,arenotstalledbySMSRPS.Thecausesareasfollows:1.Thetechniqueisverycomplicated.2.Thedevelopmentcostisveryhigh.3.Ifweintroduceforeignequipment,thecostistooexpensive.4.Foreignequipmentanditssoftwarearecompletelyclo…  相似文献   

卵形鲳鲹早期卵子发生显微及超微结构的研究   总被引：4，自引：1，他引：4  

方永强  戴燕玉  洪桂英 《台湾海峡》1996,(4)

本文研究了卵形鲳鲹早期卵子发生的显微与超微结构特点。研究结果表明在1～2龄鱼卵巢中卵原细胞进入首次成熟分裂前期的结构特点，3～4龄鱼才开始进入小生长期，文中讨论了此鱼性腺成熟的年龄以及如何加速性腺发育，为人工繁殖提供科学依据。  相似文献   

A thermal centroid or a mass centroid?     

Mingqiang Fang 《Journal of Oceanography》2006,62(5):759-766

This study reveals the physical backgrounds of the geometric centroid and the thermal centroid of the Western Pacific Warm Pool (WPWP) and points out their differences. The geometric centroid (actually a very close approximation to the mass centroid) anomaly of the surface WPWP correlates more closely with the Niño-3 region sea surface temperature anomaly (Niño-3 SSTA, an important indicator of El Niño/La Niña events) than the surface thermal centroid. Taking the WPWP depth (or heat storage) into account, the “real” mass or thermal centroid of the WPWP might correlate better with the El Niño/Southern Oscillation (ENSO) signals.  相似文献