Linear magnetic anomalies and tectonic development of the middle Okinawa Trough     

Liang Ruicai  Wu Jinlong  Liu Baohu  Wang Yong  Wang Shugong 《海洋学报(英文版)》2001,20(1):105-116

ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅＯｋｉｎａｗａＴｒｏｕｇｈ (ＯＴ) ,ｌｏｃａｔｅｄｎｏｒｔｈｗｅｓｔｏｆｔｈｅＲｙｕｋｙｕＴｒｅｎｃｈａｎｄｔｈｅＲｙｕｋｙｕｇｕｎｔｏ ,ｅａｓｔｏｆｔｈｅＥａｓｔＣｈｉｎａＳｅａｓｈｅｌｆ,ｉｓａｂａｃｋ ａｒｃｂａｓｉｎｂｕｌｇｅｄｔｏｔｈｅＲｙｕｋｙｕＴｒｅｎｃｈ .ＴｈｅＯＴｅｘｔｅｎｄｓｆｒｏｍＫｙｕｓｈｕｉｎｔｈｅｓｏｕｔｈｗｅｓｔｏｆＪａｐａｎｔｏｔｈｅＩｌａｎＰｌａｉｎｉｎｔｈｅｎｏｒｔｈｅａｓｔｅｒｎＴａｉｗａｎ ,Ｃｈｉｎａｉｎｔｈｅｓｏｕｔｈｗｅｓｔ…  相似文献   

热带地区积云对流的长期变化特征     

温之平  梁必骐 《热带海洋学报》1996,(3)

使用１９７９年１月至１９８４年１２月向外长波辐射（ＯＬＲ）资料，对热带地区积云对流的长期变化特征进行了研究。结果表明：热带地区积云对流活动存在显著的季节变化，冬季积云对流区主要是东西向，位于南印度洋和西太平洋的近赤道地区；夏季则北移至北印度洋和菲律宾附近的西太平洋地区。低纬地区积云对流活动存在明显的季节性位移，北印度洋地区的积云对流活动主要集中在５—１０月，７—８月位置最北；北半球热带西太平洋地区的积云对流活动则主要集中在６—１１月，８—９月位置最北。标准差分析表明，冬季北半球热带西太平洋、赤道中太平洋及热带印度洋东部地区积云对流的年际变化最明显。经验正交函数（ＥＯＦ）分析的主要空间型反映了赤道中太平洋、热带西太平洋、阿拉伯海和副热带西太平洋地区的积云对流活动存在一定的关系。结合遥相关计算还表明秋云对流存在４种遥相关型，即２种东西向偶极型涛动型、西太平洋型和北印度洋型。  相似文献   

鱼类寄生宫脂属线虫分种检索表     

李亮  徐真  李会敏  张路平 《海洋湖沼通报》2007,(Z1)

本文对宫脂属线虫的研究历史进行了简单的回顾,井论述了该属线虫分类中常用的一些形态学特征。依据2005年以前发表的有关宫脂属线虫的原始资料.分析了宫脂属线虫各种的形态学特征(主要包括:侧翼的有无,尾乳突的数目和分布.尾尖有无尾饰.肠盲囊和胃盲囊及食道的比值.交合刺的长度以及与体长的比值等),依据这些分类学特征编制了该属种的分类检索表。  相似文献   

渤海湾水环境氮、磷营养盐分布特点   总被引：10，自引：2，他引：10  

秦延文  孟伟  郑丙辉  雷坤  苏一兵  张雷 《海洋学报》2005,27(2):172-176

渤海是一个半封闭的陆架边缘海,主要由辽东湾、渤海湾、莱州湾及中央海区组成,面积为7.7×104 km2,平均水深18 m[1].近些年富含氮、磷营养盐的工农业废水的大量排放使得渤海湾营养盐结构发生了很大变化,同时导致渤海湾局部海域“赤潮”频繁发生.营养物质进入水体后,将会在水与沉积物之间发生迁移,其中一部分可以与钙、铁或铝络合形成沉淀,或吸附到矿物颗粒的表面而转移到沉积物中.近海沉积物可以看作营养物质的“蓄积库”.沉积物中营养物质的再生,对水体中营养盐的收支和营养盐循环动力学有着及其重要的作用[2].  相似文献   

The optimum control of thruster system for dynamically positioned vessels     

C. C. Liang  W. H. Cheng 《Ocean Engineering》2004,31(1):97-110

An offshore vessel with a dynamic positioning system (DP system) needs fast response to produce thrust to counteract the environmental forces acting on it for the purpose of maintaining its position and heading as close as possible to the working position. Therefore, quick and effective modulation of the thrust is the problem to determine the thrust and the rotation angle of the thruster devices of the ship. This paper presents an effective optimum control for a thruster system, using the sequential quadratic method to achieve economical and effective modulation of the thrust and the direction of the thruster. An optimum control study of a 2280 tons DP coring vessel with five rotary azimuth thruster marine positioning is studied in detail, which can quickly and exactly estimate the thrusts and angles of direction of all the thrusters. The results can provide a valuable thruster system for a dynamically positioned vessel.  相似文献   

Photoinduced toxicity single and binary mixtures of four polycyclic aromatic hydrocarbons to the marine diatom Skeletonema costatum   总被引：1，自引：0，他引：1  

MENG Wei  WANG Liping  ZHENG Binghui 《海洋学报(英文版)》2007,26(6):41-50

Diatom Skeletonema costatum Cleve is one of the main predominant phytoplankton species in the Changjiang Estuary in China. In order to provide some basic information for future assessment of the potential risk on phytoplankton communities in this estuary caused by polycyclic aromatic hydrocarbons(PAHs), this alga was selected as a representative to investigate the photoinduced toxicity of PAHs, in single and mixture. Four PAHs including three-ring phenanthrene and anthracene, four-ring fluoranthene and pyrene were tested in the laboratory. The single toxicity of each PAH on this microalga was compared with and without the simulated solar UV radiation. The results showed that this microalga was sensitive to PAH's photoinduced toxicity. Ratios of the 72 h median effect concentration obtained for fluorescent and UV light tests were about 8.4 for phenanthrene, 13.0 for anthracene, 6.5 for fluoranthene, and 5.7 for pyrene, indicating that UV light enhanced the PAH toxicity to this alga significantly. Under the fluorescent radiation (lacking UV), the dose-response curves based on chemical concentrations revealed that the order of toxic strength was fluoranthene greater than pyrene greater than anthracene greater than phenanthrene; while under the UV radiation (476 μW/cm2 for UVA, 6.5 μW/cm2 for UVB) it became fluoranthene approximately equaling anthracene greater than pyrene greater than phenanthrene, indicating that the UV light also changed its relative toxicity to this alga. The photoinduced toxicity of PAHs to the marine diatom S. costatum might be a synergistic effect of photosensitization reactions (e.g., generation of single-state oxygen) and photomodification (photooxidation and/or photolysis).The combined effects of six binary mixtures on the marine diatom S. costatum were investigated using the additive-index method. Four binary-mixtures (phenanthrene plus anthracene; phenanthrene plus pyrene; anthracene plus fluoranthene; anthracene plus pyrene) were found to be synergistic joint action mode, while two binary-mixtures (phenanthrene plus fluoranthene; fluoranthene plus pyrene) displayed antagonist, revealing a complex pattern of possible interactions. The combined action mode of PAHs might be related to various factors such as the mixture compounds, mixture ratios and test conditions, etc.  相似文献   

固定化鲅鱼乙酰胆碱酯酶的制备及部分性质测定   总被引：3，自引：0，他引：3  

孟范平  何东海  朱小山  马冬冬  杨正先  YANG Zheng-Xian 《中国海洋大学学报(自然科学版)》2005,35(6):1067-1071

酶的固定化是酶传感器制备过程中重要的1个环节.研究采用直接共价法固定鲅鱼乙酰胆碱酯酶（AChE）.制备方法为：0.1g CNBr活化的Sepharose 4B凝胶用1mmol/L的HCl充分溶胀后,与活力为10U的AChE溶液混合,于4℃下150r/min振荡8h.所制备的固定化酶活力回收率较高（96%）,对pH值和温度变化的适应能力均优于非固定化酶;在3个月保存期内,前者的活力损失13%,而后者的活力则下降89%.这说明固定过程能够大大提高AChE的抗逆性和保持酶活力的稳定,有利于酶传感器的制备.  相似文献   

海洋沉积物声速与物理参数的关系   总被引：4，自引：0，他引：4       下载免费PDF全文

卢博  梁元博 《海洋科学》1993,17(6):54-57

海洋沉积声速与物理性质密切相关，特别是含水量Ｗ和孔隙度Ｎ，它们在建立回归议程和预报沉积物性质中有所贡献。中国东，南海沿海沉积物的资料和数据表明：声速和声速比可以用来预报沉积物性质。  相似文献   

智能潜器的集成仿真系统     

庞永杰  徐玉如  尚游  彭良 《海洋工程》1997,(4)

本文介绍了智能潜器集成仿真系统的硬、软件结构．通过这一系统所展示的水下虚拟仿真环境能够在研究和开发智能潜器的控制体系结构、潜器载体的水动力学、信息融合和目标识别等工作中发挥巨大作用  相似文献   

南海尖峰海山多金属结壳地球化学   总被引：4，自引：5，他引：4  

梁宏锋  姚德  刘新波  梁德华 《海洋地质与第四纪地质》1991,(4)

南海尖峰海山多金属结壳富含30多种元素,其锰铁矿物主要由钡镁锰矿,δ-MnO_2和FeOOH·xH_2O组成。与其它海区的结壳相比,尖峰海山结壳富含Cu、Ni、Ba、Zn、Pb等元素,而Co、Ti、稀土元素(REE)、Sr等元素相对较贫。研究表明,HREE亏损,具明显的Ce正异常,较明显的Tb正异常和Yb负异常。这是氧化弱碱性海洋环境所致。结壳是水成作用的产物,它的形成受南海独特的古海洋环境所控制,海底火山热液作用,可能也是影响因素之一。  相似文献