Treatment of Hydrodynamic Loading for Random Sea State     

Anjan Sarkar  Suhail Ahmad  T. K. Datta M. Tech. Student Assistant Professor 《中国海洋工程》1996,(3)

- In order to employ cost effective frequency domain analysis for off-shore structures treatment of hydrodynamic loading is essential. Drag and inertia dominated, resonating and antiresonating cases under random sea states are analyzed to highlight the implications and relative merits of four salient linearization techniques.  相似文献   

东太平洋沉积物U的地球化学   总被引：4，自引：0，他引：4  

刘季花  梁宏锋 《海洋地质与第四纪地质》1996,16(1):59-67

本文对地矿部“海洋四号”科学考察船１９８７－１９８９年在东赤道太平洋ＣＣ区所取得的２７个深海表层沉积样品进行Ｕ的地球化学分析，探讨了Ｕ在深海沉积中的地球化学行为，结果表明，不同类型沉积的Ｕ含量不同，平均值由大至小的次序的含沸石粘土（２．１６×１０＾－６），硅质粘土（１．９５×１０＾－６），硅质软泥（１．６５×１０＾－６），钙质硅质粘土（１．５９×１０＾－６），在同类型沉积中Ｕ的分散性较大；Ｕ在区域  相似文献   

西沙礁序列的磁性地层学研究   总被引：3，自引：0，他引：3  

张明书  周墨清 《海洋地质与第四纪地质》1996,16(3):61-65

利用西沙群岛西琛一井３３０ｍ以上井段的１４９块岩心标本，用美国２－Ｇ型超导磁力仪进行了古地磁测定，获得了一个从更新世至中新世晚期包括布容，松山，高斯和吉尔伯特四个极性时及若干亚极性的磁性地层柱，为礁序列的划分对比，提供了新的依据。  相似文献   

Two new species of Lecithochirium LUKE, 1901(Trematodes: Hemiuridae)     

Liu Shengfa 《台湾海峡》1996,(4)

1.Lecithochiriumfukenensissp.nov.(Fig.1)(Basedon6wholemounts)ThisspiceswascollectedinthestomachofTrichiurushaumelafromXiamenandNan'ao.Bodydividedintosomaandecsoma.Soma1,31~3.48×0.426~1.05(2.69×0.737),ecsoma0.22~0.80(0.448)longwhenprotruded,usuallycomple…  相似文献   

The abyssal bounty fan and lower Bounty Channel: evolution of a rifted-margin sedimentary system     

R. M. Carter  L. Carter 《Marine Geology》1996,130(3-4):181-202

The Bounty Channel and Fan system provides the basis for a model for deep-sea channel and fan development in a rifted continental margin setting. The sedimentary system results from an interplay between tectonics (fan location; sediment source), turbidity currents (sediment supply), geostrophic currents (sediment reworking and distribution) and climate (sea level, and hence sediment supply and type). Today, sediment is shed from the collisional Southern Alps, part of the Pacific/Indo-Australian plate margin, and passes east across the adjacent shelf and into the Otago Fan complex at the head of the Bounty Trough. Paths of sediment supply, and locations of sediment deposition, are controlled by the bathymetry of the Bounty Trough, with axial slopes as high as 37 m/km (2°) towards the trough head, diminishing to around 3.5 m/km (0.2°) along the trough axis. The Bounty Fan is located 800 km further east, where the Bounty Channel debouches onto abyssal oceanic crust at the mouth of the Bounty Trough. The Bounty Fan comprises a basement controlled fan-channel complex with high leveed banks exhibiting fields of mud waves, and a northward-elongated middle fan. Channel-axis gradients diminish from 6 m/km (0.35°) or more on the upper fan to less than 1 m/km (<0.06°) on the lower fan. Parts of the left bank levee and almost the entire middle fan are being eroded and re-entrained within a Deep Western Boundary Current (DWBC), which passes along the eastern New Zealand margin at depths below 2000 m. The DWBC is the prime source of deep, cold water flow into the Pacific Ocean, with a volume of ca. 20 Sv and velocities up to 4 cm/s or greater. The mouth of the Bounty Channel, at a depth of 4950 m at the south end of the middle fan, acts as a point source for an abyssal sediment drift entrained northward under the DWBC at depths below 4300 m. The Bounty Fan probably originated in the early to middle Neogene, but has mostly been built during the last 3 Myr (Plio-Pleistocene), predominantly as climate-controlled sedimentary couplets of terrigenous, micaceous mud (acoustically reflective; glacial) and biopelagic ooze (acoustically transparent; interglacial), deposited under the pervasive influence of the DWBC.  相似文献   

一种新的海洋风场反演中风向模糊排除方法研究     

林明森  郑淑卿 《台湾海峡》1996,15(3):243-254

本文给出了一种从ＳＡＳＳ测量的后向散射强度手数据中反演出大尺度海洋风场的新方法。计算结果与Ｐｅｔｅｈｅｒｙｃｈ等利用ＳＡＳＳ表面风分析的结果比较在风向上是吻合的，在风速上本文所得结果更宇海面赵实风速。上述结果说明本文所采用的多解排除对两波束散射计探测海面风场的反演是成功的。  相似文献   

应用六氯化苯测年法对厦门港现代沉积速率的测定   总被引：2，自引：0，他引：2       下载免费PDF全文

林敏基  李木荣  许永水 《海洋与湖沼》1993,24(3):325-331

岩芯柱样用静力岩芯采样器于1986年采自福建省厦门港一九龙江口海域。通过对这些岩芯柱样中六氯化苯(BHC)的垂直分布状况和生物扰动类型的分析,应用 S_R=D_(BHC-D_(mix)/Y的计算模式,获得了这些岩芯的现代沉积速率数据。将这些数据、方法与原理完全不同的~(210)Pb放射性同位素测年法同岩芯测年数据比较,其结果在数据和数量级上有一定可比性。初步认为,再经进一步探索和改进,BHC测年法有可能应用于近岸河口港湾几十年来现代沉积速率的测定而与其它测年法互为补充。  相似文献   

Propulsive performance of three naturally occurring oscillating propeller planforms     

Pengfei Liu  N. Bose 《Ocean Engineering》1993,20(1)

A numerical method, the quasi-vortex-lattice method (QVLM), was applied to predict the propulsive performance of three naturally occurring oscillating propellers. These were cetacean flukes for a fin whale (Balaenoptera physalus); white-sided dolphin (Lagenorhynchus acutus); and white whale (Delphinapterus leucas). The fin whale's flukes had the highest aspect ratio (6.1) and moderate sweep angle (31°); the white-sided dolphin's flukes had the highest sweep angle (47°) and lowest aspect ratio (2.7); and the white whale's flukes had moderate aspect ratio (3.3) and the lowest sweep angle (28°). In the numerical simulations, the planforms were assumed to be rigid both in chordwise and spanwise directions, and to be oscillating harmonically in an irrotational, incompressible fluid. Calculation and comparisons of propulsive efficiency and thrust coefficient vs advance ratio for each of the planforms were made in three cases: varied heave amplitude; different pitching axis positions; and varied angular amplitude of pitch.  相似文献   

Distribution of chlorophyll a and diatom in the sea ice of the Weddell Sea, Antarctica     

Chen Xingqun  Gerhard Dieckmann 《海洋学报(英文版)》1991,10(1):161-166

Diatoms are major primary producers of microbial biomass in the Antarctica. They are found in the water and sea ice. The distribution, abundance of the ice diatoms and their relation to the environmental factors inside and outside the ice have been studied for its special role in the Antarctic Ocean ecology. In this paper we describe the abundance, distribution and composition of diatom assemblages in  相似文献   

Spatial and temporal variation of water mass mixing characteristic in the East China Sea     

Miao Yutian  Yu Honghua 《海洋学报(英文版)》1991,10(4):511-523

On the basis of the observation data of Kuroshio since 1984 and relative historical data in the East China Sea, spatial and temporal variation of water mass mixing characteristic in the observation area is analysed. The main results are as follows.  相似文献