流形上的空间密度聚类算法研究     

刘峰  刘希玉  刘弘 《中国海洋大学学报(自然科学版)》2007,37(4):681-684,626

研究流形上的聚类分析，针对基于密度的空间聚类引入了流形概念，提出1种基于流形的密度聚类算法，该方法将流形的概念与聚类相结合，可以适用于样本为复杂分布的聚类。文中通过实例证明此算法的有效性。  相似文献   

Ex situ target strength of rockfish (Sebastes schlegeli) and red sea bream (Pagrus major) in the Northwest Pacific   总被引：2，自引：0，他引：2  

Kang  Donhyug; Hwang  Doojin 《ICES Journal of Marine Science》2003,60(3):538-543

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The impact of salt water inflows on the distribution of polycyclic aromatic hydrocarbons in the deep water of the Baltic Sea     

Gesine Witt  Wolfgang Matthus 《Marine Chemistry》2001,74(4):246

Salt-water inflows into the Baltic Sea are important events for renewing the deep and bottom waters of the deep basins of the Baltic Sea. These events occur only at irregular intervals. The last strong event was in January 1993 followed by minor inflows in winter 1993/1994. As a result of these inflows, the deep water of the central Baltic basins was completely renewed.Based on extensive observations of polycyclic aromatic hydrocarbons (PAHs) in water, fluffy layer material and surface sediments between 1992 and 1998, the transformation of PAHs and the modification of their distribution in the Baltic deep water is discussed in connection with the spreading of the inflowing highly saline and oxygen-rich water along its pathway from the sills into the central basins. In the course of the inflows in 1993/1994, the PAH concentration in the deep water of the different basins increased significantly. The concentrations were elevated, at least by a factor of 2 and as much as seven to eight times (for the four-ring PAHs) compared to the previous and the following years. Two hypotheses for the causes were discussed: the inflowing salt water may have entrained more highly polluted surface water in the western Baltic Sea, or it may have entrained contaminated fluffy layer material or sediment particles along the route of transport.  相似文献   

Should total landings be used to correct estimated catch in numbers or mean weight-at-age?     

Lewy  Peter; Lassen  Hans 《ICES Journal of Marine Science》1997,54(3):462-470

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Strength Analysis of Turret Mooring Productive/Storage Tanker     

Zhang Shilian Jin Dexian Associate Professor 《中国海洋工程》1997,(3)

The longitudinal strength of turret mooring productive/storage tanker is studied.A numeri-cal example has been implemented according to the method presented in this paper to give practical il-lustration.From the results of the numerical example,it is concluded that the turret hole located near theforward of the amidships has small effect on the longitudinal strength of the ship hull.As for design ex-treme value of wave bending moment of storage tanker,statistic method is a more reasonablemethodology,especially with the consideration of the servere environmental conditions.The primary esti-mation of design section modulus of turret storage tanker can be determined by this design bending mo-ment.  相似文献   

欧式鳕鱼排的研制   总被引：2，自引：0，他引：2  

桑卫国  吴汉民  韩素珍 《海洋学研究》2002,20(1):55-59

以鳕鱼为原料 ,经过鱼糜制作、调味、速冻、切片、浸液、沾粉、二次速冻等工艺研制开发了欧式鳕鱼排。探讨了原、辅料和漂洗条件对产品质量的影响 ,测定了评价产品质量的感官、理化和微生物指标。  相似文献   

Consequences of growth variation in northern Baltic herring for assessment and management     

Rahikainen  Mika; Stephenson  Robert L. 《ICES Journal of Marine Science》2004,61(3):338-350

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海浪日最大波高序列的一种标度性质   总被引：1，自引：0，他引：1  

尉华  沈正 《海洋湖沼通报》1994,(4):1-8

应用重标度分析方法研究小麦岛海洋观测站１９６１－１９８０年二十年海浪日最大波高序列时发现，该序列并不是相互独立的，而是具有记忆性和持久性，详细的论证表明分式布朗运动模型是描述海浪日最大波高序列的一个较好的模型，同时，应用分式布朗运动模型我们找到了存在于海浪日最大波高序列中的一种标度性质－累积离差（ｔ）的统计自仿射性。  相似文献   

黄海多毛类异毛虫科初步研究     

赵晶  吴宝铃 《海洋科学进展》1991,(2)

本文对1987～1988年在山东省部分海岛底栖生物调查时发现的异毛虫科5个种进行了详细的描述并配有插图,其中一种为新亚种,另有3个种在我国为首次记录。  相似文献   

红罗非鱼引进繁殖育种及海水驯养研究     

常珠传  林华英  王道和  郭相平 《海洋科学》1989,13(5):44-48

作者对引进的红罗非鱼进行了生物学特性、繁殖育种及海水驯养等方面的试验研究,结果得出:①亲鱼的怀卵量与体长呈正相关(关系式为:Y=124.78L—588.8),在北方地区每年产卵3—4次,产卵量为怀卵量的1/2;②水温25—30℃,11—18d受精卵孵出鱼苗;③红罗非鱼不仅可在淡水中生存,且在自然海水和半咸水中均能生存,是海水养殖的优良品种;④红罗非鱼同虾混养,可提高鱼虾成活率,增大养成规格。  相似文献