共查询到20条相似文献，搜索用时 78 毫秒
1.
自70年代中期以来,随着大陆架(CS)、专属经济区(EEZ)和专属渔业区(EFZ)等海洋制度的建立,邻国重叠区域之间划定边界问题显得日益迫切。这种发展在有关海洋边界划定的几乎所有方面的大量文章中表示出来,然而却有一个方面未受到重视,那就是渔业在海洋边界划定中的作用。 相似文献
2.
3.
4.
本文简要描述了国际海洋边界划定与目前状况，其内容包括海洋边界划定，边界划定与海洋法，世界海洋区域及美国、俄罗斯划界概况和专属经济区与大陆架等问题。文章呼呈我国应加速海洋立法过程，尽快划出专属经济区与大陆架边界。 相似文献
5.
6.
长江口深水航道数学模型信息系统研究 总被引：3，自引：0，他引：3
利用GIS二次开发软件ArcView，完成数学模拟所需的计算网格生成及线边界法中地形数据提取的优化。集成ArcView、Visual Basic及长江口潮流数学模型，实现了数值模拟计算成果的三维可视化及实时互动的动态演示。所开发的长江口数学模型信息系统能根据整治工程需要，提交各类工程数据库。 相似文献
7.
控制圆柱体或翼型的行波壁会抑制大规模的分离流动，进而减少阻力。鱼类在游动过程中经常出现行波壁，而行波壁对鱼类游动性能的影响机制尚不清楚。以金枪鱼游动为基础，耦合行波壁，采用锐利界面浸没边界法(IBM)解决摆动过程带来的大变形运动边界问题。结果表明：行波壁的出现改变了金枪鱼体后涡的形成和发展，进而改变了摩擦阻力和压差阻力的分布；耦合行波壁使得摩擦阻力的波动幅值增加，压差阻力有所减小，从而降低了金枪鱼游动过程的阻力。研究的行波壁减阻机制可应用于提高仿生机器鱼的性能，随着智能材料的发展，该机制将在仿生机器鱼的研制中体现其现实意义。 相似文献
8.
一种新的波浪变形三维数值模式──0-1混合型边界元 总被引：4，自引：0，他引：4
为提高边界元法模拟三维波场波浪变形的数值计算精度,借鉴常数元和线性元剖分方式、波势函数及波势函数法向导数对单元节点设定的各自适应性,提出了一种新的单元剖分模式──0-1混合型边界元,以控制和减缓由于计算误差累计而造成的波浪数值计算上的“横向振动”,借此结合边界元法的分区模式可实现较大范围的波场线性波浪变形计算,并为时域内的波浪非线性变形计算提供时间步长的数值保证. 相似文献
9.
10.
垂直梯度法与最优分割法确定温跃层边界的比较分析 总被引：2，自引：2，他引：0
垂直梯度法是跃层示性特征计算中普遍使用的方法,但在某些情况下并不能很好地描述海洋要素的跃变特征.针对垂直梯度法的不足,引入水团分析中的最优分割法,对典型剖面,以及边界型、逆变型、多层型等几类特殊剖面的跃层边界分别进行了计算,并对垂直梯度法与垂直梯度法的计算结果进行了比较分析,结果表明最优分割法确定的跃层边界更为合理.通过对两种方法确定的中国近海温跃层的整体分布进行比较分析,证明了最优分割法能够弥补垂直梯度法在计算深海与浅海过渡区中的跃层时遇到的标准不匹配问题,较好地保持跃层的连续性. 相似文献
11.
SONG Zhiyao XUE Hongchao YAN Yixin
Doctor Senior Engineer College of Harbor Waterway Coastal Engineering Hohai University 《中国海洋工程》1999,(4)
To deal with the problems concerning the shore boundary,moving boundary and engineeringboundary which are encountered frequently in 2D tidal current simulation by the finite difference method,theconcept of line boundary is introduced and studied here,and then the line boundary technique in common useis proposed in this paper.Analysis of some calculation cases shows that this technique is practical,effective,and simple in 2D tidal current simulation involving different boundaries. 相似文献
12.
基于Ｐｅｄｌｏｓｋｙ（１９８７）的线性Ｍｕｃｋ边界层模型,引入一随纬向空间变化的侧摩擦系数ＡＨ（ｘ）,以探讨该参数对西边界流的强化结构的影响。结果发现,在风应力和内区解保持不变的情况下,适中线性变化的ＡＨ（ｘ）会使西边界层内的向北急流和其靠内区一侧的逆流均得到加强。文中还给出摩擦应力、相对涡度及平均动能向涡动能的转化率在西边界层内的分布情况。 相似文献
13.
本文采用分子动力学方法研究了在剪切载荷作用下,Cu(100)扭转晶界对Cu柱屈服强度的影响.模拟结果发现,在加载过程中,低角度扭转晶界形成的位错网发生位错形核与扩展,位错之间的塞积作用提高了Cu柱的屈服强度;对于高角度扭转晶界,晶界发生滑动降低了Cu柱的屈服强度.同时发现,随着扭转角度的增加,Cu柱的屈服强度先增大,当扭转角度大于临界角度时,Cu柱的屈服应力逐渐减小.这表明剪切载荷作用下,两种不同的机理主导Cu柱的屈服,对于小于临界角度的扭转晶界,Cu柱的屈服由晶界位错形核和扩展机理主导,对于大于临界角度 相似文献
14.
An improvement on the simulation of outgoing waves on a time dependent numerical model for water wave propagation in the nearshore region is presented. The governing equations consist of a system of first order partial differential equations (PDEs), the equation of continuity and the equation of motion. A comparative study of first order radiation boundary conditions (BCs) and first order radiation BCs combined with sponge layers is presented for cases where outgoing waves leave the numerical domain of calculation through the open boundary. A reduction of spurious reflections from the numerical open boundaries can be obtained with an irrelevant increase in terms of computational cost. 相似文献
15.
王莉萍 《中国海洋大学学报(自然科学版)》1991,(3)
利用多复变函数的理论,证明多复变解析函数在多圆柱区域上标准形式的Riemann—Hibert边值问题可解的充要条件,并给出解的表示式,并利用解析变换,导出多复变解析函数的一般Riemann—Hilbert边值问题的可解性。 相似文献
16.
If the upstream boundary conditions are prescribed based on the incident wave only, the time-dependent numerical models cannot effectively simulate the wave field when the physical or spurious reflected waves become significant. This paper describes carefully an approach to specifying the incident wave boundary conditions combined with a set sponge layer to absorb the reflected waves towards the incident boundary. Incorporated into a time-dependent numerical model, whose governing equations are the Boussinesq-type ones, the effectiveness of the approach is studied in detail. The general boundary conditions, describing the down-wave boundary conditions are also generalized to the case of random waves. The numerical model is in detail examined. The test cases include both the normal one-dimensional incident regular or random waves and the two-dimensional oblique incident regular waves. The calculated results show that the present approach is effective on damping the reflected waves towards the incident wave boundary. 相似文献
17.
Computational Techniques of 2D Tidal Flow in Estuaries and Bays 总被引：1，自引：0，他引：1
Xin Wenjie
Senior Engineer River Harbour Department Nanjing Hydraulic Research Institute Nanjing 《中国海洋工程》1995,(4)
- Some problems in the numerical calculation of tidal flow in estuaries and bays, such as distribution bed roughness, relationship between model moving boundary and water volume balance, remedy of certain shortage under open boundary conditions, smooth transfer of the controlling message for the inner boundaries of nested model, can not be solved usually by means of the fundamental equations and computing mode adopted in the numerical model, but can be done by the measures which not only satisfy the physical features but also are convenient for operation. Based on the calculated samples of some areas of Modaomen, Lingdingyang and Huangmaohai of the Pearl River Estuary, and Shuidong Bay (a typical barrier- lagoon tidal channel) in Guangdong Province, method and process of calculation for the above mentioned problems are briefly presented in this paper. 相似文献
18.
If the upstream boundary conditions are prescribed based on the incident wave only, the time-dependent numerical models cannot effectively simulate the wave field when the physical or spurious reflected waves become significant. This paper describes carefully an approach to specifying the incident wave boundary conditions combined with a set sponge layer to absorb the reflected waves towards the incident boundary. Incorporated into a time-dependent numerical model, whose governing equations are the Boussinesq-type ones, the effectiveness of the approach is studied in detail. The general boundary conditions, describing the down-wave boundary conditions are also generalized to the case of random waves. The numerical model is in detail examined. The test cases include both the normal one-dimensional incident regular or random waves and the two-dimensional oblique incident regular waves. The calculated results show that the present approach is effective on damping the reflected waves towards the incident wave boundary. 相似文献
19.
20.
消除"不规则频率"的非连续高阶元方法 总被引：2，自引：0，他引：2
针对使用边界元法计算波浪与结构物相互作用时所出现的“不规则频率”现象，采用连续高阶元和部分非连续高阶元对通过修改积分区域所获得的边界积分方程进行离散，有效地消除了“不规则频率”现象的发生。波浪作用下的截断圆柱所受到的水平波浪力和垂向波浪力的数值计算结果验证了该方法的有效性，同时考虑了非连续单元配置点的选择及单元划分数目对消除效果的影响。 相似文献