Wave Decay and Its Characteristics in Surf Zone     

Gu Jialong Shen Xianrong Professor  Hohai University  Nanjing Engineer  The Investigation  Design Institute  Bureau of Communications of Zhejiang Province  Hangzhou 《中国海洋工程》1991,(2)

In accordance with the similarity between breaking waves and hydraulic jumps, the expressions for estimating wave decay and wave energy dissipation in the surf zone are derived based on the fundamental equations of fluid mechanics. Using the numerical solution of cnoidal wave theory, the various kinematic properties of waves in the surf zone, including the relative wave crest height, wave energy, and radiation stress are discussed. The values calculated with the method proposed in this paper are in good agreement with the experimental data gained by other researchers. The present expressions can be used in the studies of sediment transport on gently sloping beaches, especially on muddy beaches.  相似文献   

珠江口沉积物酸挥发性硫化物与重金属生物毒性的研究     

杨永强  陈繁荣  张德荣  张凌  吕莹 《热带海洋学报》2006,25(3):72-78

研究了2003年10月采于珠江口5个站位的沉积物剖面酸挥发性硫化物(AVS)和同时提取的重金属(SEM:Pb,Zn,Cu,Cd,Ni)。其中,站位1、2位于中滩,其沉积物的AVS含量变化范围较小,为0.25—4.06μmol.g-1;站位3、4位于西滩,其沉积物的AVS含量变化范围较大,为0—26.09μmol.g-1。中滩和西滩沉积物的AVS含量均随深度增加。西滩表层沉积物的AVS含量接近于零,这可能与该水域较强的底层流和沉积物的再悬浮作用有关。站位5位于珠江口外侧,其表层沉积物的AVS含量相对较高,且垂向变化较小,可能是还原性沉积物间歇性再悬浮后重新沉积的结果。站位1、2和5沉积物中同时提取的重金属含量大体在0.95±0.2μmol.g-1范围内,随深度增加略呈下降趋势;而西滩沉积物重金属含量相对较高,为1.43—2.42μmol.g-1,且在一定深度范围内随深度增加呈明显下降的趋势,表明珠江口西滩沉积物中的重金属污染有加重的趋势。对AVS/SEM摩尔比值和单个金属的毒性效应研究显示,珠江口内尤其是西滩的表层沉积物存在重金属污染,对其中生活的底栖生物具有潜在的毒性效应。  相似文献   

钢筋混凝土梁结构断裂损伤诊断方法     

周尚志  王丽华刘瑛 《海洋工程》2005,23(4):47-51

提出一种基于BP神经网络的结构破损诊断方法,该方法以结构破损前后柔度的变化作为破损诊断网络输入,为了解决由于系统响应样本数据空间分布不均匀对网络收敛速度及网络诊断影响问题,对网络训练样本采用广义空间格点进行了交换,模拟算例及应用实例均表明,本文方法能准确诊断结构破损位置与破坏程度,是一种有效的结构破损诊断方法.  相似文献   

凡纳滨对虾生物学及养殖生态学研究进展   总被引：32，自引：0，他引：32  

王兴强  马甡  董双林 《海洋湖沼通报》2004,(4):94-100

凡纳滨对虾原产于太平洋沿岸水域秘鲁北部至墨西哥桑诺拉一带。1988年由张伟权教授引进我国。本文对国内外凡纳滨对虾生物学及养殖生态学的研究进行了总结，提出了凡纳滨对虾养殖生态学今后研究的方向。  相似文献   

中国鱼类名录ⅩⅢ——鲽形目、纯形目、海蛾鱼目、鮟鱇目     

李明德  张世禄王迎 《海洋通报》2003,22(6):56-62

鲽形目3亚目8科51属142种。鲀形目2亚目9科57属143种。海蛾鱼目1科2属3种，鮟鱇目3亚目11科23属41种。  相似文献   

Action of Cnoidal Waves on Vertical Walls     

Qiu Dahong  Zang Jun  Jia Ying Academician of the Chinese Academy of Sciences  Professor  the State Key Laboratory of Coastal  Offshore Engineering 《中国海洋工程》1996,(2)

Based on the 2nd order cnoidal wave theory, the characters of shallow water standing waves and their action on vertical walls are studied in this paper. The theoretical expressions of the wave surface elevation in front of and the wave pressure on the vertical wall are obtained. In order to verify the theoretical results, model tests were made in the State Key Laboratory of Coastal and Offshore Engineering at DUT. For the wave surface elevation in front of the wall and the wave forces on the wall at the moment when the wave surface at the wall surface goes down to the bottom of the wave trough, the calculated results coincide quite well with the experimental results. For the wave forces on the wall at the moment when the wave surface at the wall surface goes up to the top of the wave crest, the theoretical expressions are modified by the experimental results. For the convenience of practical use, calculations are made for the wave conditions which usually occur in enginering practice by use of the inves  相似文献   

Dynamic Response Analysis of Interaction System of R.C. Gravity Single-Leg Platform     

Cao Guoao Shen Yilei Dr.Professor  Tongji University  Shanghai Shanghai College of Architectural  Municipal Engineering  Shanghai 《中国海洋工程》1991,(1)

In this paper, the responses of the interaction system of R.C. gravity single-leg platform to seismic excitation are mainly analysed. A set of nonlinear equations for the interaction system are established by using the wave, one is the soil-structure interaction and the other is the fluid-structure interaction. The seismic response of the interaction system is analysed for the influence of the asymmetric structure, fluid action, etc. with the input of seismic SH waves in any direction. The numerical results are given for a simple example.  相似文献   

The behaviour of ⁵⁹Fe in marine microhabitat     

Cai Fulong  Chen Ying  Xu Pi''an  Oiu Manhua 《海洋学报(英文版)》1989,8(3):423-429

Under the artificial condition the 59Fe morphology in sea water, its concentration in sediment and phytoplankton, its distribution and metabolism in tissue organs of marine animals were studied. The results showed that the morphology of 59Fe was in a particulate state in sea water. The adsorption rule of 59Fe by three kinds of sediments was similar. The concentration ability of 59Fe by phytoplankton was very strong. The critical concentration organs of S9Fe by marine animals were viscera. The gross radioactivity of 59Fe was mainly concentrated in protein. The concentration factor of 59Fe by DNA was the highest one. After excretion experiment, 59Fe of all the tissue organs was not detected. Small part of59Fe remained in the organic acid and protein state. There was a redistribution process in sediment for59Fe.  相似文献   

Study of zooplankton ecology in Zhejiang coastal upwelling system-Zooplankton biomass and abundance of major groups   总被引：1，自引：0，他引：1  

He Dehu  Yang Guanming  Fang Shaojin  Shen Weilin  Liu Hongbin  Gao Aigen  Huang Shuxin 《海洋学报(英文版)》1988,7(4):607-620

The studied area is a shallow water area that belongs to the East China Sea continent shelf. The distribution of zooplankton biomass is higher inshore than offshore. The maximum abundance is in the inshore edge of the centre of upwelling, which is the superposed area of the salinity front and temperature front, due to the fact that the mixture of three different waters has brought about a concentration of nutrients. The herbivorous Euphausia, Copepoda and Tunicata are the major groups of the abundant area. Tunicata possess the possibility to compete against other kinds of herbivorous zooplankton. This means that there is negative correlation between the distribution of Tunicata and that of Copepoda and Euphausia. The positions of maximum areas of zooplankton biomass, phytoplankton individual and the concentration of phosphates and chlorophyll-a overlap one another. In the centre of upwelling, zooplankton can not adapt itself to the environment of lower temperature and less oxygen even with rich nutrient  相似文献   

温度、pH对缢蛏(Sinonovacula constricta)消化酶活力的影响   总被引：8，自引：0，他引：8  

范德朋  潘鲁青  肖国强  马甡  董双林 《海洋湖沼通报》2003,(4):69-73

本文研究了温度、pH对缢蛏(Sinonovacula constricta(Lamarck))三种主要消化酶(蛋白酶、淀粉酶和纤维素酶)活力的影响。结果表明：当温度在5～75℃之间时，蛋白酶、纤维素酶和淀粉酶的最适温度分别为为55℃、45℃和65℃；在不同的pH范围内，蛋白酶的最适PH值为9．2，淀粉酶的最适PH值为6．3和7．7，纤维素酶的最适PH值为5．2。缢蛏的淀粉酶和蛋白酶活力较大，纤维素酶活力极微。  相似文献