黑鲷和青石斑鱼对气泡幕反应的比较     

赵锡光  何大仁  刘理东 《中国海洋大学学报(自然科学版)》1997,(1)

在室内水池中观察了黑鲷（Ｓｐａｒｕｓｍａｃｒｏｃｅｐｈａｌｕｓ）和青石斑鱼（Ｅｐｉｎｅｐｈｅｌｕｓａｗｏａｒａ）对孔径０．５ｍｍ、孔距５．０ｃｍ，空气压力０．２５ｋｇ／ｃｍ２固定气泡幕的反应。结果表明，气泡幕对两种海水鱼都有显著的阻拦作用，平均阻拦率分别为黑鲷７５．１％、青石斑鱼８２．４％。分析显示，气泡幕对两种鱼的阻拦率间无显著差异。在本实验中，该两种鱼对气泡幕均无明显的适应现象  相似文献   

小直径组合桩的波浪力实验分析   总被引：2，自引：1，他引：2  

王爱群  徐立论 《海洋湖沼通报》2002,(1):9-17

本文给出小直径孤立桩、两个桩和2×2个桩的波浪作用力实验结果。在波浪水槽中以0°,45°,90°三个波浪方向测量了各桩所受的纵向力和横向力,文中讨论了组合桩之间的干扰效应,给出了干扰系数随KC数和桩距的变化。  相似文献   

低围压水平下砂的排水行为(英文)   总被引：2，自引：1，他引：2  

杨少丽  Rolf Sandven  冯秀丽  林霖 《中国海洋大学学报(自然科学版)》2001,31(3):441-447

采用干样沉降法制备样品 ,选用静三轴仪对松砂和密砂样在 10 k Pa至 10 0 k Pa的低围压下的排水行为进行了实验研究 ,并对实验结果作了橡皮膜校正 ,在围压为 10 k Pa的密砂实验中 ,轴向应力的校正值可达到 12 %。实验研究表明低围压下松砂的剪胀性非常明显 ,且存在剪应力极值 ;围压越低 ,松砂和密砂的剪应力极值越小 ,达到最大剪应力所对应的剪应变越小。同时还表明低围压范围内相对密度不同 ,砂的应力应变特性不同 ;此外 ,低围压下砂的内摩擦角高于高围压下的值 ,从而在工程上应重视低围压水平下砂土工程参数的合理选取  相似文献   

北极海冰减少的气候效应研究   总被引：2，自引：0，他引：2  

魏立新  张海影 《海洋预报》2005,22(Z1):56-61

本文采用了OSU两层大气环流模式对特定的北极海冰进行数值模拟,研究北极海冰减少的气候效应.试验中海温一律取为气候平均值,北极海冰作为外强迫源影响大气,大气响应完全是环流内部调整的结果.本文对北极海冰减少后的大气环流特征进行了分析,特别是与中国的气温和降水之间的关系.  相似文献   

Mach Effect of Oblique Nonlinear Irregular Waves Interacting with Vertical Walls     

冯卫兵潘丽红  洪广文 《中国海洋工程》2004,18(2):299-306

Based on Hong‘s theory, previous random models, and a generalized expression suitable for FIT calculation, the interaction between irregular waves and vertical walls is numerically simulated. The results of simulation demonstrate that the wave energy changes with the incidence angle and the distance from the wall. Particularly, the Mach effect and the combined wave spectrum characteristics are analyzed in detail, which are significant in both theory and practice.  相似文献   

Wave runup on a concentric twin perforated circular cylinder     

K. Vijayalakshmi  S. Neelamani  R. Sundaravadivelu  K. Murali 《Ocean Engineering》2007,34(2):327-336

The regular wave interaction with a twin concentric porous circular cylinder system consisting of an inner impermeable cylinder and an outer perforated cylinder was studied through physical model and numerical model studies. The experiments were carried out on the twin concentric cylinder model in a wave flume to study the wave runup and rundown at the leading and trailing edges of the perforated cylinder. It was found that the maximum wave runup on the perforated cylinder is almost same as the incident wave height. The experimental results were used to develop the predictive formulae for the wave runup and rundown on the perforated cylinder, which can be easily used for design applications. The wave runup profiles around the perforated cylinder for different values of ka and porosities were studied numerically using Green's Identity Method. The results of the numerical study are presented and compared with the experimental measurements.  相似文献   

Ultimate strength of ship hulls under torsion     

Jeom Kee Paik  Anil K. Thayamballi  P. Terndrup Pedersen  Young Il Park 《Ocean Engineering》2001,28(8):51

For a ship hull with large deck openings such as container vessels and some large bulk carriers, the analysis of warping stresses and hatch opening deformations is an essential part of ship structural analyses. It is thus of importance to better understand the ultimate torsional strength characteristics of ships with large hatch openings. The primary aim of the present study is to investigate the ultimate strength characteristics of ship hulls with large hatch openings under torsion. Axial (warping) as well as shear stresses are normally developed for thin-walled beams with open cross sections subjected to torsion. A procedure for calculating these stresses is briefly described. As an illustrative example, the distribution and magnitude of warping and shear stresses for a typical container vessel hull cross section under unit torsion is calculated by the procedure. By theoretical and numerical analyses, it is shown that the influence of torsion induced warping stresses on the ultimate hull girder bending strength is small for ductile hull materials while torsion induced shear stresses will of course reduce the ship hull ultimate bending moment.  相似文献   

0516号热带风暴过程分析     

李孟植 《海洋预报》2007,24(3):40-45

利用气象海洋数据资料和卫星遥感图片,分析研究了2005年第16号热带气旋"韦森特"(VICENTE)的特征,从最先的初始扰动到自身环流的分裂发展重组过程,以至当时周围相对应的大气环流,发现该热带气旋活动过程具有很多特性。对其移动过程进行的综合分析表明,只要存在合适距离等一定有利的条件,弱的两个涡旋之间完全可以发生强的作用力,高空辐散场的抽气作用对气旋的发展有极好的作用,所得的结论可对今后的预报提供一些启示和参考。  相似文献   

透射射线的非线性效应     

夏冬明  王修田  蒋卫焱 《中国海洋大学学报(自然科学版)》2006,36(5):705-708

根据Snell定律提出了透射射线的非线性效应的概念,从理论上证明了当地震射线的轨迹在1个界面上为1条直线时在另1个界面上可为1条曲线;并进一步通过射线追踪实验证明:当地下介质为非水平层状介质时,即使对应于地面同一条直线段上的接收点,来自地下同一个界面上的反射点的轨迹仍可为一条曲线。  相似文献   

河口变形效应与涌潮的形成     

杜勇 《中国海洋大学学报(自然科学版)》1989,(3)

作者采用非线性潮波方程,假定河口的宽度B(x)和深度h(x)是任意可微函数,导出了涌潮发生的条件,并讨论了各种变形情况下涌潮的形成。得出结论是,在涌潮形成过程中起决定作用的是浅水非线性效应,而河口变形效应则是起促进作用的。  相似文献