某船坞南翼墙基岩水下控制爆破技术     

徐清明  穆旭 《海岸工程》1997,16(3):47-54

本文介绍的基岩水下爆破属临近重要建筑物的水下控制爆破。当岩石裂隙发育，且岩面有较厚的石碴覆盖层，其技术难度大，采取的诸如搭钢平台钻孔。塑料套管护孔，以及孔间、排间塑料导爆管雷管接力式微差起爆网路等措施，都是成功之经验，值得今后类似工程推广应用。  相似文献   

闽南：台湾浅滩渔场变性水团的初步分析     

何发祥 《海洋湖沼通报》1994,(3):18-25

根据聚类方法，对闽南－台湾浅滩渔场变性水团进行划分，本海区共有６个变性水团。讨论各个变性水团在不同季节消长变化规律。  相似文献   

长江口及济州岛邻近海域温、盐、密度的跃层现象     

孙日彦  周培强  赵继胜 《中国海洋大学学报(自然科学版)》1990,(1)

本文根据CTD观测资料,分析了研究海区的温、盐、密度跃层的分布与变化,讨论了逆温逆盐层的分布区域,并从跃层角度出发,分析了深层水的涌升,黄海冷水团的上边界以及台湾暖流在东海北部的影响范围。  相似文献   

Relative molar mass distributions of chromophoric colloidal organic matter in coastal seawater determined by Flow Field-Flow Fractionation with UV absorbance and fluorescence detection     

Martin Hassellv 《Marine Chemistry》2005,94(1-4):111

A new method for the characterization of chromophoric colloidal organic matter in seawater has been applied to samples from the Baltic Sea, Kattegatt and Skagerrak seas. Size fractionation of the sample by Flow Field-Flow Fractionation and measurement of the fluorescent and UV absorbing properties of the individual size fractions result in a relative molar mass distribution (RMM) of the optical properties. The RMM distributions have been used to estimate number and weight average relative molar masses, and polydispersity indices. At least two sources of coloured organic matter were identified from the ratio of fluorescence to UV: the Baltic surface water and the Skagerrak deep water. The dominating processes were mixing and dilution, but processes such as photo bleaching of fluorescence are also believed to be important. The RMM distribution derived from UV detection (1150–1300 Dalton) increased with increasing salinity while that derived for fluorescence (1500–1250 Dalton) decreased with increasing salinity. The specific UV absorbance taken as a proxy of the aromaticity of the chromophoric organic material showed decreasing trend with both increasing salinity and increasing UV derived weight average relative molar mass. Increasing polydispersity of the colloidal material was also observed as a function of salinity.  相似文献   

An alternative approach to the structural motion analysis of wedge-beam offshore structures supporting a load     

J. S. Wu  K. -W. Chen 《Ocean Engineering》2003,30(14):1791-1806

For convenience of dynamic analysis, some offshore structures such as fixed-type platforms are often modeled as the wedge beams supporting tip lumped masses. It is well-known that, due to the effect of the surrounding water, the natural frequencies of a beam in air (or dry beam) are different from those of the same beam immersed in water (or wet beam). However, if the natural frequencies and the associated mode shapes of a dry beam are calculated by taking account of the “added mass” for the immersed beam, then the last natural frequencies and mode shapes will be equal to the corresponding ones of the wet beam. Based on the last concept, the closed form solutions for natural frequencies and the associated mode shapes of the dry beam were determined first, then the partial differential equation of motion for the wet beam was transformed into a matrix equation by using the expansion theorem and the foregoing closed form solutions of free vibration responses for the dry beam. Solving the last matrix equation will give the required natural frequencies and the associated mode shapes of the wet beam. The formulation of this paper is available for the fully or partially immersed double tapered beams with either circular, square or rectangular cross-sections. The taper ratio for width and that for depth may be equal or unequal. The numerical results of this paper were compared with the existing results or the finite-element-method results and good agreement was achieved.  相似文献   

The Formation and Circulation of the Intermediate Water in the Japan Sea   总被引：1，自引：0，他引：1  

Jong-Hwan Yoon  Hideyuki Kawamura 《Journal of Oceanography》2002,58(1):197-211

In order to clarify the formation and circulation of the Japan/East Sea Intermediate Water (JESIW) and the Upper portion of the Japan Sea Proper Water (UJSPW), numerical experiments have been carried out using a 3-D ocean circulation model. The UJSPW is formed in the region southeast off Vladivostok between 41°N and 42°N west of 136°E. Taking the coastal orography near Vladivostok into account, the formation of the UJSPW results from the deep water convection in winter which is generated by the orchestration of fresh water supplied from the Amur River and saline water from the Tsushima Warm Current under very cold conditions. The UJSPW formed is advected by the current at depth near the bottom of the convection and penetrates into the layer below the JESIW. The origin of the JESIW is the low salinity coastal water along the Russian coast originated by the fresh water from the Amur River. The coastal low salinity water is advected by the current system in the northwestern Japan Sea and penetrates into the subsurface below the Tsushima Warm Current region forming a subsurface salinity minimum layer. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

舟山渔场及其邻近海域水团的季节特征   总被引：5，自引：0，他引：5  

张启龙  王凡  赵卫红  唐晓晖 《海洋学报》2007,29(5):1-9

根据2001年夏季和2002年冬季两次现场调查所收集的CTD和营养盐资料,利用模糊聚类分析法,对舟山渔场及其邻近海域水团的季节特征进行了分析.结果表明,舟山渔场及其邻近海域水团的配置、分布范围、温盐特性和营养盐含量都有明显的季节特征.其中,冬季在全海域共有3个水团(江浙沿岸水、台湾暖流表层水和黄海混合水),而夏季则存在4个水团(江浙沿岸水、台湾暖流表层水、台湾暖流深层水和黄海混合水);冬季,江浙沿岸水的分布范围较小,温度偏低,盐度略高,营养盐偏高,而夏季,其分布范围较大,温度偏高,盐度偏低,营养盐偏低;冬季,台湾暖流表层水北伸最强,厚度最厚,温度最低,盐度最高,硅酸盐和硝酸盐偏高,而夏季,则北伸最弱,厚度最薄,温度最高,盐度最低,硅酸盐和硝酸盐偏低;台湾暖流深层水是一个季节性水团,它含有较丰富的营养盐;黄海混合水的分布范围和营养盐含量也都呈现出明显的季节特征.  相似文献   

Numerical simulation of the hydrodynamic behaviour of submerged plane nets in current     

Yu-Cheng Li  Yun-Peng Zhao  Fu-Kun Gui  Bin Teng 《Ocean Engineering》2006,33(17-18):2352-2368

The aim of this paper is to investigate the shape and tension distribution of fishing nets in current. A numerical model is developed, based on lumped mass method to simplify the net. The motion equation is set up for each lumped mass. The Runge–Kutta–Verner fifth-order and sixth-order method is used to solve these simultaneous equations, and then the displacement and tension of each lumped mass are obtained. In order to verify the validity of the numerical method, model tests have been carried out. The results by the numerical simulation agree well with the experimental data.  相似文献   

应用卫星遥感边缘效应解译冬季黄海的水团配置     

刘宝银  苏育嵩 《中国海洋大学学报(自然科学版)》1989,(1)

作者提出叶绿素是海洋浮游植物生物量的一个重指标,在两水系交汇的锋区,由于浮游植物大量繁殖,叶绿素富集,处于高生产力状态。同步获取黄海叶绿素在富集带及邻近外区的分布,可以确定水团边界。对此,作者根据卫星图象经几何纠正后,通过与黄海叶绿素a的边缘效应信息及区域分布态势比较并解译,将冬季黄海的水团划分为八种。本文还引证了遥感与其它常规资料佐证。  相似文献   

东海西北部水团分析及与渔场的关系     

刘树勋  韩士鑫  魏永康 《中国海洋大学学报(自然科学版)》1989,(Z1)

作者用聚类分析法划分浅海水团,目的在于克服大洋水团分析法进行分析所遇到的一些困难,它在根据不同海区特点确定临界值与检验值时有较大的灵活性。本文讨论了浅海变性水团与中心渔场的关系。结果表明,东海底层冷水、东海表层水和大陆沿岸水对渔业生产有重要影响。  相似文献