Stream Function Wave Derived by Unified Variational Principle of Water Gravity Wave     

Fu Yuhua Senior Engineer  China Offshore Oil Production Research Center  P.O.Box  Beijing 《中国海洋工程》1997,(2)

Based on the linear wave,solitary wave and fifth order stokes wave derived by use of the Uni-fied Variational Principle of Water Gravity Wave(UVPWGW),this paper derives stream function wavetheory by using UVPWGW.This paper will handle the Kinematic Free Surface Boundary Condition(KFSBC)and Dynamic Free Surface Boundary Condition(DFSBC)directly and give the optimum solu-tion,instead of the conditions ∑(Q_(av)-Q_i)~2=min,and the related equations of stational condition.When the wave height H,period T and water depth D are given,the original stream function wave willbe determined,and can not be adjusted if it does not agree with the real case;in the present method,the ad-justment can be done by adding several constraint conditions,for example,the wave profile can be ad-justed according to the condition of accurate peak position.The examples given in this paper show that forthe original stream function wave,the DFSBC can be fairly well satisfied,but the KFSBC can not;howev-er,the stream function wave derive  相似文献   

基于自适应BP网络的涌潮波速计算模型     

廖迎娣  张玮 《海洋工程》2003,21(4):70-74

运用BP网络附加动量法和自适应学习速率法，建立神经网络模型，模拟计算涌潮波速。根据部分试验数据对网络进行训练，确定相关参数，建立涌潮波速计算模型，同时利用其余部分试验数据对模型进行检验，模拟结果与试验数据吻合较好，相关程度高，表明神经网络模型用于计算涌潮波速是合适的。  相似文献   

对虾、青蛤和江蓠三元混养效益的实验研究     

王大鹏  田相利  董双林  常杰  包杰  马甡  王继业 《中国海洋大学学报(自然科学版)》2006,36(Z1):20-26

通过海水陆基围隔实验,研究了凡纳滨对虾(Litopenaeus vannamei)与青蛤(Cyclina senensis)、菊花心江蓠(Gracilaria lichevoides)投饵混养的适宜配比、经济效益和生态效益。实验结束时对虾的体重、成活率和净产量分别为5.30~6.12g,62.96%~78.21%和1 065.0~1 367.6kg.hm-2。青蛤体重和净产量分别为6.85~7.15g,和51~328kg.hm-2。菊花心江蓠净产量为3 900~9 380kg.hm-2。混养系统的经济效益和生态效益均优于对虾单养。在本实验条件下,混养系统的最佳结构为凡纳滨对虾30ind.m-2,青蛤30ind.m-2,菊花心江蓠200g.m-2;其N,P绝对利用率分别为52.94%和26.09%。  相似文献   

Interannual Changes of the Winter to Early Spring Biomass and Composition of Mesozooplankton in the Kuroshio Region in Relation to Climatic Factors     

Kaoru Nakata  Sachiko Koyama 《Journal of Oceanography》2003,59(2):225-234

Interannual variations of biomass of major mesozooplankton groups (Cnidaria, Chaetognatha, Copepoda, Crustacea other than copepods, Tunicata) in the January to March period were examined in the slope, Kuroshio and offshore waters off the Pacific coast of western Japan (western region) from 1971 to 1988 and off central Japan (central region) from 1971 to 1989. The mean biomass for each year of most of the mesozooplankton groups was high in the early 1970s and tended to decrease (in the western region) or to have dropped to a lower level (in the central region) after the mid-1970s. Stepwise multiple linear regression analyses of the mean biomass for each year of each mesozooplankton group in the Kuroshio in both regions against climatic factors revealed that the biomass was related positively to wind speed. It is therefore considered that the nutrient supply to the upper layers limits the production of many of the mesozooplankton groups examined in the Kuroshio, even in winter. Similar relationships were also found for the biomass of Copepoda, non-copepod Crustacea and Tunicata in the offshore water in the western region. The percentage of copepods in the biomass in the central region seemed to decrease under high water temperature conditions, while that of Chaetgnatha tended to increase. Climatic factors thus largely influenced the interannual variations of biomass and composition of mesozooplankton in and near the Kuroshio during the winter to early spring period. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

Variation of underwater ambient noise observed at IORS station as a pilot study     

Bong-Chae Kim  Bok Kyoung Choi 《Ocean Science Journal》2006,41(3):175-179

The Ieodo Ocean Research Station(IORS) is an integrated meteorological and oceanographic observation base which was constructed on the Ieodo underwater rock located at a distance of about 150 km to the south-west of the Mara-do, the southernmost island in Korea. The underwater ambient noise level observed at the IORS was similar to the results of the shallow water surrounding the Korean Peninsula (Choi et al. 2003) and was higher than that of deep ocean (Wenz 1962). The wind dependence of ambient noise was dominant at frequencies of a few kHz. The surface current dependence of ambient noise showed good correlation with the ambient noise in the frequency of 10 kHz. Especially, the shrimp sound was estimated through investigations of waveform and spectrum and its main acoustic energy was about 40 dB larger than ambient noise level at 5 kHz.  相似文献   

Behaviour of Cyclopoid, Harpacticoid, and Calanoid Copepods from Coastal Waters of Taiwan   总被引：1，自引：0，他引：1  

Jiang-Shiou  Hwang Jefferson T.  Turner 《Marine Ecology》1995,16(3):207-216

Abstract. Cinematographic techniques were used to compare behaviour patterns of three cyclopoid, one harpacticoid, and two calanoid species of copepods from coastal waters of Taiwan. Behaviour was quantified in terms of allocation of time to swimming versus non-swimming behaviour, and behavioural transitions/minute. The different species of copepods exhibited different patterns of behaviour. Oithona nana and O. similis had long periods of inactivity punctuated by comparatively few transitions to intermittent leaps of motion. Oncaea venusta had a more jerky pattern of numerous small hops with frequent transitions between motion and rest. Macrosetella gracilis spent more time swimming than did the cyclopoids, but with fewer behavioural transitions than O. venusta , more like the Oithona species. Temora turbinala swam virtually continuously and transitions to non-swimming were rare. Undinula vulgaris var. taiwanicus frequently alternated between upward motion and sinking at rest, making a feeding current about a fourth of the time. There was considerable intraspecific variability between individual animals, but for reasons of experimental design, it was impossible to statistically test the significance of this variation. Differences in behaviour patterns between the different species are discussed within the context of what is known about the feeding ecology of these species from previous investigations.  相似文献   

Assessment of acoustic iterative inverse method for bubble sizing to experimental data     

Bok Kyoung Choi  Bong -Chae Kim  Byoung -Nam Kim  Suk Wang Yoon 《Ocean Science Journal》2006,41(4):195-199

Comparative study was carried out for an acoustic iterative inverse method to estimate bubble size distributions in water. Conventional bubble sizing methods consider only sound attenuation for sizing. Choi and Yoon [IEEE, 26(1), 125–130 (2001)] reported an acoustic iterative inverse method, which extracts the sound speed component from the measured sound attenuation. It can more accurately estimate the bubble size distributions in water than do the conventional methods. The estimation results of acoustic iterative inverse method were compared with other experimental data. The experimental data show good agreement with the estimation from the acoustic iterative inverse method. This iterative technique can be utilized for bubble sizing in the ocean.  相似文献   

34万吨级FPSO的中横剖面优化设计   总被引：4，自引：1，他引：4  

骆伟唐文勇  张圣坤范模 《海洋工程》2004,22(4):7-11,18

以中横剖面的面积最小为目标函数，应用自适应步长随机搜索法，对34万吨级FPSO中横剖面进行了优化设计，并将规范设计结果和优化设计结果进行了比较，优化效果较好。  相似文献   

Cod (Gadus morhua L.) migration speeds and transport relative to currents on the north-east Newfoundland Shelf     

Rose  G. A.; deYoung  B.; Colbourne  E. B. 《ICES Journal of Marine Science》1995,52(6):903-913

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Movements of cod (Gadus morhua L.) in relation to the tidal streams in the southern North Sea     

Arnold  G. P.; Walker  M. Greer; Emerson  L. S.; Holford  B. H. 《ICES Journal of Marine Science》1994,51(2):207-232

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