黄海陆架表层水温的低频振动     

周发琇  于慎余 《中国海洋大学学报(自然科学版)》1987,(4)

本文在对位于黄海南部陆架上的朝连岛站30年水温资料进行分析时发现,该站的表层水温有周期大于20个月的低频振动,其中以准两年周期和6年周期最显著。陆架水温的这种低频振动是对东亚季风异常的响应。这种低频振动在冬季与渤海冰情的变化同步;在夏季与黄海底层冷水团的强弱相关。同时,这种低频振动在对马暖流上也有一定的反映。  相似文献   

Fluctuations of peak energy and peak frequency of local wavelet energy spectrum for wind waves     

Wu Kejianl  Lou Shunli 《海洋学报(英文版)》1997,16(4):429-439

Ｆｌｕｃｔｕａｔｉｏｎｓ　ｏｆ　ｐｅａｋ　ｅｎｅｒｇｙ　ａｎｄ　ｐｅａｋ　ｆｒｅｑｕｅｎｃｙ　ｏ　ｌｏｃａｌ　ｗａｖｅｌｅｔ　ｅｎｅｒｇｙ　ｓｐｅｃｔｒｕｍ　ｆｏｒ　ｗｉｎｄ　ｗａｖｅｓTXＦｌｕｃｔｕａｔｉｏｎｓｏｆｐｅａｋｅｎｅｒｇｙａｎｄｐｅａｋ...  相似文献   

A Method of Coding and Decoding in Underwater Image Transmission     

程恩 《海洋通报(英文版)》2001,3(2)

A new method of coding and decoding in the system of underwater image transmission is introduced, including the rapid digital frequency synthesizer in multiple frequency shift keying,image data generator, image grayscale decoder with intelligent fuzzy algorithm, image restoration and display on microcomputer.  相似文献   

An integrated growth study for North Atlantic albacore (Thunnus alalunga Bonn. 1788)   总被引：1，自引：0，他引：1  

Santiago  J.; Arrizabalaga  H. 《ICES Journal of Marine Science》2005,62(4):740-749

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海洋立管复模态动力特性分析   总被引：1，自引：0，他引：1  

郭海燕  齐晓亮  娄敏 《中国海洋大学学报(自然科学版)》2006,36(6):991-994

考虑阻尼的影响,研究海洋立管的动力特性。通过分析管内流体及管外海洋环境荷载的共同作用,建立海洋立管涡激振动偏微分方程,进而得到立管动力特性方程,用复模态分析法求解动力特性方程得到立管考虑阻尼的自振频率。算例计算表明:考虑阻尼的立管自振频率略小于不考虑阻尼的立管自振频率;立管的自振频率随着内流流速的增加而减小,但内流流速不大时,影响较小;管道长度对立管的自振频率影响较大。  相似文献   

Turbulent dispersion in the ocean     

Chris Garrett   《Progress in Oceanography》2006,70(2-4):113

The mathematical framework for turbulent transport in the ocean is reasonably well established. It may be applied to large-scale fields of scalars in the ocean and to the instantaneous or continuous discharge from a point. The theory and its physical basis can also provide an interpretation of passive scalar spectra. Spatial variations in the rate of turbulent transfer can be related to the movement of the center of mass of a scalar and to a formulation in terms of entrainment. The relative dispersion of a scalar with respect to its center of mass and the streakiness of the concentration field within the relative dispersion domain need to be considered. In many of these problems it is valuable to think in terms of simple models for individual streaks, as well as overall statistical properties.  相似文献   

Baroclinic Buoyancy-Inertia Joint Stability Parameter     

Hideo Kawai 《Journal of Oceanography》2005,61(2):235-246

At present, the barotropic buoyant stability parameter has been derived from a vertical virtual displacement of a water parcel. The barotropic inertial stability parameter in the eccentrically cyclogeostrophic, basic current field was derived in 2003 from a horizontal cross-stream virtual displacement of a parcel. By expressing acceleration of a parcel due to a virtual displacement, which is arbitrarily sloping within a vertical section across the basic current, in terms of natural coordinates, we derived the vertical component of baroclinic buoyant stability parameter B ₂ ², the horizontal component of baroclinic inertial stability parameter I ₂ ², the baroclinic joint stability parameter J ², its buoyant component B ² and its inertial component I ². B ² is far greater than I ₂ ², and when neglecting relative vorticity except for vertical shear, a downward convex curve of J ² plotted against the slope of a virtual displacement follows a trend of B ² curve. If a parcel displaces along a horizontal surface or an isopycnal surface, however, B ² vanishes, and J ² becomes equal to I ². Actual parcel is apt to displace not only along the bottom slope, but also along the sea surface and an isopycnal interfacial surface, which is approximately equivalent to an isentropic surface, preferred by lateral mixing and exchange of momentum. Such actual displacement makes B ² vanishing, and grants I ² an important role. The present analysis of I ² examining effects due to curvature and horizontal and vertical shear vorticities are useful in deepening our understanding of baroclinic instability in actual oceanic streams.  相似文献   

投喂频率对南美白对虾(Penaeus vannamei Boone)生长、饲料利用及虾体组成影响的初步研究   总被引：5，自引：0，他引：5  

周歧存  郑石轩  高雷  齐雪娟 《海洋湖沼通报》2003,(2):64-68

本实验选用商品饲料饲养平均初体重为0．09g的南美白对虾，经过30d的生长实验，研究不同投喂频率对南美白对虾生长、成活以及饲料利用的影响。结果表明，随着投喂频率由3次／天增加到5次／天，南美白对虾的增重率、特定生长率和蛋白质效率显著提高，而饲料系数则显著降低，但当投喂频率由5次／天增加到7次／天时，南美白对虾增重率、特定生长率和蛋白质效率并无显著提高。对对虾全虾体主要组成成分的分析表明南美白对虾体主要组成成分并不受投喂频率增加的影响。  相似文献   

Comparing the modelled and measured target-strength variability of walleye pollock, Theragra chalcogramma     

Hazen  Elliott L.; Horne  John K. 《ICES Journal of Marine Science》2004,61(3):363-377

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Estimation of birthdates and catch-at-age using length frequency analysis (LFA), with application for skipjack tuna (Katsuwonus pelamis) caught in the Southwest Atlantic     

Andrade  Humber A.; Kinas  Paul G. 《ICES Journal of Marine Science》2004,61(5):798-811

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