Multipole expansions for wave diffraction and radiation in deep water

A multipole expansion of the velocity potential is described for two- and three-dimensional wave diffraction and radiation problems. The velocity potential is expressed in terms of a series of multipole potentials. The wave terms and the local disturbance terms are represented by separated multipole potentials. Floating bodies and submerged bodies are treated in the same way. This approach differs from that of some other authors, who considered floating bodies and submerged bodies separately and derived entirely different multipoles. Semi-analytical solutions for a circular cylinder in two-dimensional motions are given. It is found that the local disturbance decays rapidly and steadily. The general application of the multipole expansion to arbitrary geometries is also presented, based on a method coupling multipoles to a boundary integral expression. Numerical results for several floating and submerged cylinders are presented.     

Dynamic Analysis of a Single-Column Platform (II)

This paper describes the study of a single-column structure used as well-head platform. In order to check the reliability of computation theory and programme, model tests have been carried out. The paper introduces the conclusion of tests and the dynamic properties of single-column platform are obtained.     

锶诱导的氧化胁迫对叉鞭金藻(Dicrateria inornata)的影响

采用不同浓度的锶胁迫方法研究了叉鞭金藻生长、叶绿素、MDA含量及三种抗氧化酶SOD、CAT、GPX活性的变化。结果表明，在实验设计的各种Sr^2 浓度内叉鞭金藻均能生长，但Sr^2 浓度较高时生长受到不同程度的抑制，细胞数量比对照组分别减少15．9％和51．0％；叉鞭金藻中叶绿素含量随着Sr^2 浓度的升高而降低，呈负相关关系；叉鞭金藻中MDA含量在较低Sr^2 浓度下稍呈下降趋势，但与对照组相比并无显著差异，而在23．04mmol／L Sr^2 浓度时是对照的1．25倍；低Sr^2 浓度时，叉鞭金藻中蛋白质含量没有大的变化，当浓度超过5．76mmol／L时则引起蛋白质含量下降；叉鞭金藻中抗氧化酶SOD在低Sr^2 时分别降低12．5％、7．5％和9．5％，高Sr^2 时显著升高，为对照组的85．7％；CAT、GPX活性在低Sr^2 浓度时差别不大，但当浓度为23．04mmol／L时升高显著，比对照组分别增加了19．8％和74．4％。     

东营城区高精度三维地震采集方法研究

根据东营城区内建筑物较多，环境干扰较大，地下构造复杂，断裂非常发育，目的层埋藏深，资料信噪比较低的特点，以地震老资料和钻井资料为基础，建立地震地质模型，利用射线追踪技术选取合适的观测系统参数。充分利用卫星数字地图，没计了灵活多变的观测系统，采用可控震源与炸药震源配合使用方法，及时对城区内地下面元的覆盖次数、方位角和炮检距的分布进行质量监控，利用现场处理系统对资料进行及时分析，提高了地震资料品质。所获得的东营城区高精度三维地震采集资料显示，其浅中层分辨率和中深层信噪比都有了明显改善，取得了良好的地质效果。     

遥感与GIS支持下的海洋渔业空间分布研究——以东海为例

基于海洋渔业多年来生产实践所表明的海洋渔场与海洋水文要素密切相关性,将研究区的遥感融合信息与生产数据进行GIS空间配准,同时建立了诸多要素数据的空间聚类模式,利用该模式提取了水文信息和中心渔场信息相关联的空间分布规律的隐伏信息,由此阐述了实现海洋渔业现代化,应用空间遥感融合信息和GIS支持下指导海洋渔业生产的渔情预报有着重要意义.     

太平洋表层海温的年代际变化

众所周知，ENSO(El Nino/ Southern Oscillation)是发生在热带太平洋的年际时间尺度上最强的气候信号，与 El Nino (La Nina)相应的正(负)海温距平(SSTA)主要分布于赤道中东太平洋地区(Rasmusson et al.，1982)。相对于热带太平洋的年际ENSO现象，人们注意到北太平洋海平面气压(SLP)存在更长周期的年代际变化(Trenberth et al.，1994)，有人认为这与北太平洋的表层温度(SST)变化有关(Latif et al.，1994)，也有人认为与热带SST的异常关系更为密切(Jacobs et al.，1994)。20世纪80年代后的ENSO事件和20世纪60，70年代有明显的差别(Wang，1995)，20世纪90年后El Nino发生频数增加，并且在1997和1998年出现了20世纪最强的一次Nino事件(McPhaden，1999)。 因此，不论是作为大气年代际变化可能的一个驱动因子，还是作为年际ENSO的背景场，从整体上了解太平洋SST的年代际时间尺度上的时、空变化特征都是十分重要的。     

Study on copper complexing ligand concentrations in several China’s coastal waters

Copper complexing ligand concentrations in the Daya Bay, Qingdao coast, Jiaozhou Bay, South China Sea and Huanghe Estuary waters were determined by the anodic stripping voltammetry technique. The distribution regularity and the relationship with other parameters were discussed. The results were as follows: Copper complexing ligand concentrations of the South China Sea were a little higher than those of other sea areas, and they were apparently higher than those of the ocean. Compared with the subsurface layer (SSL) in the sea surface microlayer copper complexing ligand concentrations showed an enrichment phenomenon, of which the mechanism is similar to dissolved organic matter. The metal complexing ligand concentration profiles of the South China Sea showed that the value in the sea surface was the highest, then it decreased with depth accruing, and a higher value appeared at the bottom. Copper complexing ligand concentrations were higher than those of cadmium and lead. Ligands in each sea area exhibited a complicated property. In short, the distribution regularity of copper complexing ligand concentrations in China' s coastal waters was consistent with that of other regions in the world. Meanwhile, the positive relationship between the copper complexing ligand concentrations and biological oxygen demand, chemical oxygen demand, dissolved organic carbon, and viscosity were found clearly.     

假单胞菌(Pseudomonas sp.cn4902)磷酸甘油磷酸酯酶基因克隆与鉴定

采用随机克隆、功能筛选、逐次排除和同源比较的基因克隆新策略进行克隆假单胞菌(Pseudomonas sp．cn4902)磷酸甘油磷酸酯酶基因的研究。结果表明，该结构基因长819bp，与铜绿假单胞菌的磷酸甘油磷酸酯酶基因的核苷酸一致性达61．5％，氨基酸同源性为56．2％。该基因已输入GenBank数据库，收录号AF348165。将该基因转化大肠杆菌，受体菌在含NaCl 1．0mol／L的培养基中甘油含量升高2．9倍，最终菌浓度提高3．6倍。可见这是一个与生物耐盐性相关的主基因，以其转化、培育耐盐农作物的前景十分光明。     

“数字海底”系统建模中的关键技术研究

基于“数字海底”系统的理论基础研究和在海底科学应用中的具体实践,提出了“数字海底”的涵义、系统组成和体系结构,对空间数据管理技术、基于XML的WebGIS空间数据表达技术、复杂海底三维建模技术、多源信息的一体化集成显示技术、虚拟现实技术等“数字海底”系统建模中的关键技术进行了探讨,为从事海底资源研究和开发的人员提供各个层次的参考或帮助.     

A General Linear Wave Theory for Water Waves Propagating over Uneven Porous Bottoms

Starting from the widespread phenomena of porous bottoms in the near shore region, considering fully the diversity of bottom topography and wave number variation, and including the effect of evanescent modes, a general linear wave theory for water waves propagating over uneven porous bottoms in the near shore region is established by use of Green‘s scond identity. This theory can be reduced to a number of the most typical mild-slope equations curreutly in use and provide a reliable research basis for follow-up development of nonlinear water wave theory involving porous bottoms.