赤潮发生机理研究──海洋原甲藻的氮营养生理特征   总被引：17，自引：1，他引：17  

黄晓航  史冬梅  张京浦  刘海航  吴超元 《海洋与湖沼》1997,28(1):33-38

于１９９１年１月－１９９１年１２月，以不同浓度的硝态氮（２０，６０，２００，６００μｍｏｌ／Ｌ）研究对赤潮生物海洋原甲藻的生长和生化组成的影响，及其营养生理特性，结果表明，在氮浓度为２００和６００μｍｏｌ／Ｌ时，表现光合作用强，细胞生长快，指数生长期长，叶绿素含量高，提示了由原甲藻爆发引起的赤潮与海洋富营养化有直接关系，结果还表明，海洋原甲藻可以累积蛋白质和碳水化合物，当外界氮源不能满足生长需要时  相似文献   

应用遗传神经网格方法分析赤潮监测数据   总被引：1，自引：1，他引：1  

杨建强  高振会  孙培艳  石强  李钦亮 《海洋科学进展》2002,20(2):77-82

简要介绍了遗传神经网络方法的原理 ,探讨了应用遗传神经网络方法研究辽东湾海域丹麦细柱藻 (Leptocylindrusdanicus)赤潮与其环境因子之间的关系 ,计算了各环境因子对丹麦细柱藻赤潮的贡献。结果表明 ,温度、盐度、DIN的变化对研究海域丹麦细柱藻种群密度的增长有比较重要的影响 ,DIN是营养限制因子。遗传神经网络是分析赤潮监测数据的有效方法 ,值得进一步探索  相似文献   

Methodical series tests for fuller ship hull forms     

B. Della Loggia  L. Doria 《Ocean Engineering》1980,7(6):659-706

In recent years many fuller ship hull forms have been designed and constructed in various shipbuilding countries, but the data available for the development of the fuller forms are inadequate from the point of view of preliminary ship design. In this paper the authors describe how they have systematically tested vessel forms of block coefficients ranging from 0.80 to 0.90. The analysis and presentation of the test results have been made in such a manner that designers can produce hull forms like those of tankers and other bulk carriers quickly and reliably.  相似文献   

The Huelva (Spain) Tsunami-Ready Station and Its Interaction with Storm Emma (March 2018)     

Jue Lin-Ye  Begoña Pérez-Gómez  Enrique Álvarez-Fanjul  Javier García-Valdecasas 《Marine Geodesy》2020,43(5):509-539

Abstract

The sea level station operating since 1996 at Mazagón (Huelva, Spain) has been progressively upgraded to fit tsunami warning requirements, due to its location in one of the main regions at risk. Its radar water level sensor was complemented in 2017, with the addition of a pressure sensor. The performance of both sea level sensors and their response to sea level oscillations, at different frequencies, is assessed. Particular emphasis is put on the effect of extreme events, such as Storm Emma, when alternative methods to obtain 1-min data are tested, in contrast to the one based on arithmetic means. The overall differences are small, for the whole period of study (centered-root-mean-square-error below 1?cm, for 5-min, and hourly data; similar tidal parameters and sea level oscillations with periods between 30?s and 5?min). However, during Storm Emma, the pressure sensor presents sensibly lower readings than the radar, with the centered-root-mean-square-error rising to 80?mm on the March 2^nd 2018. A new method to compute 1-min data, based on medians, reduced this value to 10?mm for the same day.  相似文献   

近40a来海南岛南岸的相对海平面变化     

吴小根 《海洋科学》1997,21(1):56-60

根据海南岛榆林验潮站１９５４～１９９２年连续３９ａ潮位观测资料，经过统一基准面校正后，运用多种统计分析方法研究，得出近４０ａ来海南岛南岸的相对海平面变化呈上升趋势，相应的平均上升速率为０．６４ｍｍ／ａ，这一数值较近百年来１～２ｍｍ／ａ的全球海平面上升速率明显偏小，反映出同期海南岛南岸的地面是微弱抬升的。  相似文献   

Filters for linear sea-wave prediction     

M.R. Belmont  J.M.K. Horwood  R.W.F. Thurley  J. Baker 《Ocean Engineering》2006,33(17-18):2332-2351

Deterministic sea-wave prediction (DSWP) models are appearing in the literature designed for quiescent interval prediction in marine applications dominated by large swell seas. The approach has focused upon spectral methods which are straightforward and intuitively attractive. However, such methods have the disadvantage that while the sea is aperiodic in nature, the standard discrete spectral processing techniques force an absolutely periodic structure onto the resulting sea surface prediction models. As it is the shape of the sea surface that is important in such applications, particularly near the end of the domain which is important, the standard windowing techniques used in signal processing work to reduce leakage artifacts cannot be employed. This has necessitated the use of end matching methods that can be both inconvenient and may reduce the fraction of the time for which legitimate predictions are available. As a result, an investigation has been undertaken of the use of finite impulse response prediction filters to provide the necessary dispersive phase shifting required in DSWP systems. The present work examines the theoretical basis for such filters and explores their properties together with their application to both long and short crested swell seas. It is shown that wide band forms of such filters are only convergent in the sense of distributions having both infinite duration impulse responses and asymptotically divergent first derivatives. However, appropriate band limitation can produce useful finite impulse responses allowing implementation via standard discrete convolution methods. It is demonstrated that despite the prediction filters having a non-causal impulse response such filters can be used in practice due to a combination of the asymmetric nature of the impulse response and the fundamental nature of the prediction process. The findings are confirmed against actual sea-wave data.  相似文献   

基于神经网络的平底结构砰击压力预报   总被引：1，自引：0，他引：1  

陈震  肖熙 《海洋工程》2005,23(2):26-31,41

对利用神经网络预报平底结构入水砰击压力的方法进行了探讨。首先利用仿真软件计算各种情况下平底结构入水所产生的砰击压力，以此形成训练神经网络的数据集。其次利用数据集对三层反馈式网络进行了训练，讨论了不同隐含层节点数对该非线性系统的拟合能力，并且对梯度下降法、动量修正法和基于优化的LM算法的有效性和精度进行了比较，最后得出了适合平底结构入水砰击系统的网络结构。  相似文献   

1999年以来台湾及邻近海域7.5级以上强震前的条带现象     

张年明  郑健志 《台湾海峡》2005,24(4):426-432

中国台湾地区地处欧亚板块与菲律宾海板块之间,地震活动频繁．本文报道了 我国台湾地区及其邻近海域1985～2002年间5．5级以上地震的条带内外频度比分 布,并着重研究了1999—2002年中发生的3次7．5级以上地震前的条带现象．其结 果表明:台湾地区近期发生的3次7．5级以上大地震前,5．5级以上地震呈条带分 布．这些条带符合条带内地震个数Nin≥6的条件,符合条带内、外频度比Nin／(Nin Nout)≥75％的条件,也符合条带长宽比大于5的要求,只是与板内地震条带相比,条 带的长度较短．  相似文献   

利用归一化层速度预测和研究储层物性的方法     

李刚 《海洋地质与第四纪地质》2003,23(1):125-129

归一化层速度是对任意深度处的层速度进行归一化处理的一种速度形式，归一化处理的目的是把任意深度处的层速度转换为与深度无关的格式，归一化后层速度的横向变化主要取决于地层岩性，孔隙度等物性的变化，利用这一特点可以方便地利用已知钻井资料对其进行标定，比较简单地进行地层岩性，孔隙度等特性的预测。实际应用表明，其预测结果与钻井揭示吻合较好，预测效果令人满意。  相似文献   

粘土矿物去除赤潮生物的动力学研究   总被引：12，自引：3，他引：12  

俞志明  邹景忠  马锡年  王利峡 《海洋与湖沼》1995,26(1):1-6

于１９９２年４－９月进行粘土矿的絮凝赤潮生物（微型原甲藻）的动力学研究；考察粘土种类、浓度、第二组分（ＰＡＣＳ）和ＰＨ等因素对絮凝速率的影响，建立粘土矿物絮凝赤潮生物的动力学模型，从理论上分析和讨论各种因素的影响，并提出提高絮凝速率的方法和途径。结果表明，高岭土体系絮凝速率大于蒙脱土体系，其速率方程可用双分子反应来描述。其中，速率常数随絮凝过程发生变化；粒子间的相互作用能和作用半径是控制和影响絮凝  相似文献