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   

On the estimation of mooring line characteristic resistance for reliability analysis     

Roberto Montes-Iturrizaga  Ernesto Heredia-Zavoni  Francisco Silva-Gonzlez 《Applied Ocean Research》2007,29(4):239-241

The main aim of this work is to derive a correct formulation for the characteristic resistance of a mooring line segment with lognormally distributed component resistances and substitute an equation proposed by Vazquez-Hernandez et al. [Vazquez-Hernandez AO, Ellwanger GB, Sagrilo LVS. Reliability-based comparative study for mooring lines design criteria. Appl Ocean Res 2006; 28(6):398–406] in a paper published in this journal, which is not correct. The mooring line is considered as a series system and the resistances of individual components of a line segment are statistically independent and identically distributed; furthermore, the case of normally distributed component resistances is also discussed. A comparison with the corresponding equation proposed by DNV-OS-E301 is given. Results show that the formula proposed by Vazquez-Hernandez et al. [Vazquez-Hernandez AO, Ellwanger GB, Sagrilo LVS. Reliability-based comparative study for mooring lines design criteria. Appl Ocean Res 2006; 28(6):398–406] overestimates quite significantly the characteristic resistance of a mooring line segment.  相似文献   

Parameter identification of a compliant nonlinear SDOF system in random ocean waves by reverse MISO method     

R. Panneer Selvam  S. K. Bhattacharyya   《Ocean Engineering》2001,28(9):33

The determination of the drag and inertia coefficients, which enter into the wave force model given by Morison's equation, is particularly uncertain and difficult when a linear spectral model is used for ocean waves, and the structure is compliant and has nonlinear dynamic response. In this paper, a nonlinear System Identification method, called Reverse Multiple Inputs–Single Output (R–MISO) is applied to identify the hydrodynamic coefficients as well as the nonlinear stiffness parameter for a compliant single-degree-of-freedom system. Four different types of problems have been identified for use in various situations and the R–MISO has been applied to all of them. One of the problems requires iterative solution strategy to identify the parameters. The method has been found to be efficient in predicting the parameters with reasonable accuracy and has the potential for use in the laboratory experiments on compliant nonlinear offshore systems.  相似文献   

Applied hydrodynamic wave-resistance computation by Fourier transform     

Jorge D'Elia  Mario A. Storti  Sergio R. Idelsohn 《Ocean Engineering》2002,29(3):261-278

An applied Fourier transform computation for the hydrodynamic wave-resistance coefficient is shown, oriented to potential flows with a free surface and infinity depth. The presence of a ship-like body is simulated by its equivalent pressure disturbance imposed on the un-perturbed free surface, where a linearized free surface condition is used. The wave-resistance coefficient is obtained from the wave-height downstream. Two examples with closed solutions are considered: a submerged dipole, as a test-case, and a parabolic pressure distribution of compact support. In the three dimensional case, a dispersion relation is included which is a key resource for an inexpensive computation of the wave pattern far downstream like fifteen ship-lengths.  相似文献   

非线性共轭梯度法在东海黑潮流计算中的应用   总被引：4，自引：0，他引：4  

陈红霞  袁业立  刘娜  曲媛媛 《海洋学报》2003,25(6):31-38

基于现有的几种海流计算方法,根据与P矢量法相同的动力特性和内在假设,对海流计算提出了一种简单、高效、易扩展、适用范围广的新方法:非线性共轭梯度法.利用1989年4月以来的"中日黑潮合作调查研究"6个航次的CTD资料,对东海黑潮流区域应用非线性共轭梯度法进行了海流计算.通过与船载ADCP实测结果比较表明,非线性共轭梯度法是可行的.  相似文献   

In-Situ Observation of Fluid Mud in the North Passage of Yangtze Estuary, China   总被引：1，自引：0，他引：1  

李九发  万新宁何青应铭  时连强S.M.Hutchinson 《中国海洋工程》2004,18(1):149-156

Observations of fluid mud were made in the lower North Passage of the Yangtze Estuary in February 2000, on 10 -11 August 2000, on 30 - 31 August 2000 (after two strong typhoons), on 21 - 24 August 2000 (neap tide) and on 3 -6 September 2000 (mean tide) respectively. In situ data show that the fluid mud in this area consists of fine cohesive sediment (median size 7.23 μm). The formation and movement of fluid mud varied during the neap-spring and flood-ebb tidal cycle. Observations suggest that fluid mud phenomena in this area may be categorised in a three-fold manner as slack water, storm and saltwedge features. The thickness of the fluid mud layer of slack water during the neap tide ranged from 0.2 to 0.96 m, whereas during the mean tide, the thickness ranged from 0.17 to 0.73 m, and the thickness of the fluid mud layer was larger during slack water than at the flood peak. Shoals cover an area of 800 km^2 with a water depth smaller than 5 m. Erosion of these extensive intertidal mudflats due to storm action provides an abundant sediment source. This is particularly significant in this estuary when the tidal level is lower than 5 m. The lower North Passage is a typical zone of saltwater wedging, so the saltwedge fluid mud has the most extensive spatial range in the estuary.  相似文献   

日本鳗鲡早期阶段耳石日生长轮形成的周期   总被引：7，自引：0，他引：7  

李城华  沙学绅 《海洋与湖沼》1995,26(4):408-413

于1990年4月从江苏太湖搜集日本鳗鲡亲鱼暂养在天津滨海虾场8t玻璃钢水槽中，经人工催熟催产后孵出仔鳗，对孵出仔鳗连续取样；于1989年4月在长江口采集白仔鳗，观察和比较二者的耳石生长轮形成。结果表明，（1）人工繁殖仔鳗耳石第一个生长轮是在孵出后第一天形成的，轮纹形成具有24h周期性；仔鳗孵出后生长天数与生长轮数关系的回归方程以y=0．23＋0．91x表示，其中，x为孵出后的天数，y为生长轮数;在人工繁殖仔鳗耳石上没有观察到“孵化标记”轮。（2）白仔鳗耳石中心核与“孵化标记”轮之间存在日生长轮。（3）人工繁殖仔鳗与白仔鳗耳石中心核同第一个生长轮比较表明，前者小于后者。  相似文献   

近海海面上水汽向上输送的季节性差异     

陈绍鑫 《海洋湖沼通报》1994,(2):202-207

本文分析了雷达观测结果，发现近海海面上的水汽向上输送随季节而变化，由于季节的变化和不同的天气情况，海表面大气现象在雷达中有不同的显示，根据这些显示得到了不同的信息，由此而得出春秋两季海表面水汽向上输送量的不同。  相似文献   

利用地质雷达探测青岛港木质高桩码头承台完整性   总被引：1，自引：0，他引：1  

单红仙 《海岸工程》1997,(4)

利用EKKO－100型探地雷达对青岛港木质高桩码头承台完整性进行探测，结合现场钻探、孔内波速测试、岩样分析测试，进一步对码头的工程性状进行了分析和评价。  相似文献   

青岛浮山野生花卉种质资源   总被引：2，自引：0，他引：2  

李宝华  张建福 《海洋湖沼通报》1996,(4):74-84

本文简要叙述了青岛浮山野生花卉的种类、生长环境、园林用途及开花结果日期，为把这些野生花生花卉引进城市园林提供科学依据。  相似文献