Reliability-Based Optimal Design for Very Large Floating Structure     

张淑华 《中国海洋工程》2003,17(1)

1 .ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅａｐｐｒａｉｓａｌｏｆａｇｏｏｄｄｅｓｉｇｎｆｏｒａｖｅｒｙｌａｒｇｅｆｌｏａｔｉｎｇｓｔｒｕｃｔｕｒｅ(ＶＬＦＳ)ｔｈａｔｗｉｌｌｓｅｒｖｅｉｎａｓｐｅｃｉ ｆｉｅｄｏｃｅａｎａｒｅａｒｅｑｕｉｒｅｓｔｈａｔｔｈｅｓｔｒｕｃｔｕｒａｌｓｙｓｔｅｍｂｅｅｃｏｎｏｍｉｃａｌｌｙｄｅｓｉｇｎｅｄ ,ｔｈｅｒｅｑｕｉｒｅｍｅｎｔｓｆｏｒｉｔｓｆｕｎｃｔｉｏｎｂｅｓａｔｉｓｆｉｅｄａｎｄｔｈｅｓｔｒｕｃｔｕｒｅｋｅｅｐｓｓｔａｂｌｅｉｎｉｔｓｗｈｏｌｅｓｅｒｖｉｃｅｐｅｒｉｏ…  相似文献   

中国近海鱼类生活史型与生态学参数地理变异   总被引：11，自引：0，他引：11  

罗秉征 《海洋与湖沼》1992,23(1):63-73

根据1985－1986年东海北部近海调查材料及其它有关文献，对43种鱼计74个种群或群体的生活史选择型及其生态参数进行了比较研究。结果表明，分布于我国近海的主要鱼类大多偏于r选择型。对r－K选择鱼种的资源特征及其对捕捞的反应作了阐述。各鱼种的种群生态学参数在种间和空间分布均表现出地理变异。  相似文献   

周期浅析     

战淑芸  杨淑瑞 《海洋预报》1992,9(4):47-51

本文分析了滑动平均的数据处理方法对周期分析结果产生的影响。提出了过程变量同号积分的数据处理方法,并对亚洲西风指数序列进行了试验分析。分析结果表明,周期的长短与振幅的大小有密切关系,亚洲逐日西风指数的周期振荡具有明显的季节特征。  相似文献   

Simulations of Annual Cycle of Phytoplankton Production and the Utilization of Nitrogen in the Yellow Sea     

Tian?TianEmail author  Hao?Wei  Jian?Su  Changsoo?Chung 《Journal of Oceanography》2005,61(2):343-357

A nutrient dynamic model coupled with a 3D physical model has been developed to study the annual cycle of phytoplankton production in the Yellow Sea. The biological model involves interactions between inorganic nitrogen (nitrate and ammonium), phosphate and phytoplankton biomass. The model successfully reproduces the main features of phytoplankton-nutrient variation and dynamics of production. 1. The well-mixed coastal water is characterized by high primary production, as well as high new production. 2. In summer, the convergence of tidal front is an important hydrodynamic process, which contributes to high biomass at frontal areas. 3. The evolution of phytoplankton blooms and thermocline in the central region demonstrate that mixing is a dominant factor to the production in the Yellow Sea. In this simulation, nitrate- and ammonium-based productions are estimated regionally and temporally. The northern Yellow Sea is one of the highly ranked regions in the Yellow Sea for the capability of fixing carbon and nitrogen. The annual averaged f-ratio of 0.37 indicates that regenerated production prevails over the Yellow Sea. The result also shows that phosphate is the major nutrient, limiting phytoplankton growth throughout the year and it can be an indicator to predict the bloom magnitude. Finally, the relative roles of external nutrient sources have been evaluated, and benthic fluxes might play a significant role in compensating 54.6% of new nitrogen for new production consumption.  相似文献   

Seasonally Hypersaline Estuaries in Mediterranean-climate Regions     

J.L. Largier  J.T. Hollibaugh  S.V. Smith 《Estuarine, Coastal and Shelf Science》1997,45(6):789-797

Data collected in three Californian estuaries indicate that hypersaline conditions exist during the dry summers typical of a Mediterranean climate. The generalised seasonal and longitudinal hydrographic structures are described and explained. It is argued that this seasonal hypersalinity is common and that it represents a major class of estuaries. The observed accumulation of salt indicates surprisingly long residence times in small basins which have free exchange with the ocean. This semi-isolation of the inner basin leads to a large build-up or severe depletion of nutrients, pollutants and plankton in these systems. Of concern are the trends to increase pollutant loading in the same systems that are experiencing an increase in residence times owing to freshwater extraction in the watershed.  相似文献   

浒苔(Enteromorpha prolifera)生活史的初步研究   总被引：39，自引：0，他引：39  

王晓坤  马家海  叶道才  陈孝德 《海洋通报》2007,26(5):112-116

通过实验室培养实验,全面地观察描述了浒苔生活史各个阶段的发育情况。雌雄异体的配子体成熟后,放散双鞭毛的配子,雌雄配子结合成合子进而发育成孢子体,配子也可以进行单性生殖发育成膜状的配子体。孢子体成熟放散四鞭毛的游孢子,游孢子固着后,可直接发育成配子体。其生活史是单倍体的配子体与二倍体的孢子体相互交替的同形世代交替。雌雄配子具有正趋光性,易大量聚集,结合后同游孢子一样都呈负趋光性。  相似文献   

Excess CO2 and pHexcess in the Intermediate Water Layer of the Northwestern Pacific     

Andrey Andreev  Makio Honda  Yuichiro Kumamoto  Masashi Kusakabe  Akihiko Murata 《Journal of Oceanography》2001,57(2):177-188

Excess CO₂ and pH_excess showing an increase in dissolved inorganic carbon and a decrease in pH from the beginning of the industrial epoch (middle of the 19th century) until the present time have been calculated in the intermediate water layer of the northwestern Pacific and the Okhotsk Sea. It is concluded that: (1) The Kuril Basin (Okhotsk Sea) and the Bussol' Strait areas are characterized by the greatest concentrations of excess CO₂ at isopycnal surfaces due to the processes of formation and transformation of intermediate water mass. (2) The largest difference in excess CO₂ concentration between the Okhotsk Sea and the western subarctic Pacific (about 8 µmol/kg) is found at the = 27.0. (3) The difference in excess CO₂ between the western subarctic Pacific and subtropical regions is significant only in the upper part of the intermediate water layer ( = 26.7–27.0). (4) About 10% of the excess CO₂ accumulation in the subtropical north Pacific is determined by water exchange with the subarctic Pacific and the Okhotsk Sea.  相似文献   

Cod migration patterns in relation to temperature: analysis of storage tag data   总被引：1，自引：0，他引：1  

Stensholt  Boonchai K. 《ICES Journal of Marine Science》2001,58(4):770-793

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动荷载作用下海底粉土的孔压响应及其动强度   总被引：5，自引：0，他引：5  

冯秀丽  叶银灿  马艳霞  林霖 《中国海洋大学学报(自然科学版)》2002,32(3):429-433

本文选用近海分布较广的粉土为研究对象 ,利用室内动三轴试验结果 ,找出动荷载作用下粉土的动应力应变关系 ,分析模拟波浪荷载作用下粉土中的孔压响应、临界循环次数 ,确定波浪作用下粉土的应力状态、破坏临界循环次数 ,判断不同深度处的粉土发生液化的可能性及发生液化所需要的时间 ;研究粉土在动荷载作用下的强度降低 ,为海上工程设计和施工提供科学依据。  相似文献   

黄、渤海无机氮的收支模式初探   总被引：8，自引：1，他引：8  

王保栋  单宝田  战闰  藏家业 《海洋科学》2002,26(2):33-36

根据黄、渤海无机氮的收支状况，首次提出了黄、渤海无机氮的稳态收支模式。模式研究结果表明，大气沉降、陆源输入和海底输入的无机氮通量分别占黄、渤海无机氮浮游植物总需求量的3%、4%和12%。无机氮的外部输入约占总需求量的1/5，其他部分则由水柱中的内部再循环（再生）供给。  相似文献