Design of ship's bow form by potential-based panel method

A surface panel method treating a boundary-value problem of the Dirichlet type with the free surface is presented to design a three-dimensional body corresponding to a prescribed pressure distribution. The free surface boundary condition is linearized with respect to the oncoming flow, and computed by four-point finite difference scheme. Sample designs for submerged spheroids and Wigley hull are carried out to demonstrate the stable convergence, the effectiveness and the robustness of the method. The design of a 5500TEU container carrier is performed with respect to reduction of the wave resistance. To reduce the wave resistance, calculated pressure on the hull surface is modified to have the lower fluctuation, and is applied as a Dirichlet type dynamic boundary condition on the hull surface. The designed hull form is verified to have the lower wave resistance than the initial one not only by computation but also by experiment.     

Assessment of the effects of hydrocarbon contamination on the sedimentary bacterial communities and determination of the polar lipid fraction purity: Relevance of intact phospholipid analysis

This in situ study reports on the relevance of intact phospholipids as new biomarkers and highlights the limits of the classical fatty acid analysis after the hydrolysis of the polar lipid fraction. The analysis of polar lipid fractions revealed significant contributions of marine macrophytes with either non-phospholipid compounds (sulfoquinovosyl diacylglycerol) or with both non-bacterial phospholipid classes (phosphatidylcholine) and non-bacterial phospholipid molecular species (some molecular species of phosphatidylglycerol). The analysis of intact phospholipids showed also the predominance of gram-negative bacteria in sediments whereas the analysis of fatty acids alone cannot confirm such information. Lastly, as regard to the effects of petroleum hydrocarbons on the sedimentary bacterial communities, we observed a higher degree of saturation of the fatty acyl chains of the phospholipids extracted from sediment exposed to a massive and chronic crude oil contamination. Such a result was interpreted as an adaptive response resulting in higher membrane rigidity of the bacterial communities.     

On the estimation of mooring line characteristic resistance for reliability analysis

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.     

一种评价重金属污染对大型海藻毒性效应的新方法

提出一种监测污染物对大型海藻毒性效应的新方法。该方法仅需将在有害环境中生长或２的大型海藻置于一封闭的、经０．４５μｍ膜过滤的海水体系中,在一定条件下培养１ｈ（设白、黑二瓶）,之后测定白、黑二瓶ＰＨ值并设计其差值△ＰＨ,再同样测定对照组白、黑二瓶ＰＨ差值△ＰＨ,计算△ＰＨ／△ＰＨ,则此计算值可用来代表相对光合作用速率,并用于评价毒性效应大小,另外,还较详昼地论证了该方法的水化学依据。     

海洋微藻中若干活性物质的开发现状与展望

海洋微藻的开发应用是近几年国内,外的研究热点之一,预计在本世纪末和下世纪半有更大的发展。本文概述了开发利用海洋微藻生产β－胡萝卜素,不饱和脂肪酸,蛋白质及其他生物活性物质的国内,外研究现状与展望。     

Corrected Formula of Bed Resistance Coefficient for Plane Numerical Simulation of Tidal Current

By means of a logarithm law for the velocity profile,a corrected formula of bed resistancecoefficient,which involves many factors such as gradient of still water depth,variation of surfaceelevation,flow direction,and so on,is derived from the 3D governing equations of tidal current by aver-aging over the whole water depth.Theoretical analysis and application have shown that the 2D plane tidalcurrent numerical model would be more reasonable and could be applied to steep bottom topographywhen the corrected bed resistance coefficient is used,therefore the results of reproduction simulation andengineering calculation would be more scientific and reasonable.     

浅海桶形基础平台抗拔力与抗倾稳定分析

平台在海上受风、浪、流、冰等水平载荷作用产生倾斜 ,而土壤粘接力、摩擦力和土抗力是平台的抗拔和抗倾力 ,桶基平台应满足抗拔、抗倾稳定的要求 ,以保证平台的整体稳定性。讨论了桶基平台受水平力作用时 ,桶形基础的破坏模式及其计算方法 ,阐述了抗倾稳定计算方法     

海水仔稚鱼脂类营养研究进展

近年来国外海水仔稚鱼脂类营养研究取得了重要进展。作者从海鱼鱼卵和早期仔稚鱼阶段的脂肪酸成分、海水仔稚鱼饥饿时脂肪酸的保存、海水仔稚鱼脂类的消化、吸收和运输、饲料中磷脂的作用和影响、饲料磷脂与甘油三酯的效率、饲料的必需脂肪酸、必需脂肪酸的定量需要、高度不饱和脂肪酸以及EPA和DHA比例的重要性等方面综述脂类营养对海水仔稚鱼生长的影响     

辽宁海洋生态系统恶化的经济学阐释

文章在辨析和定义海洋生态系统概念的基础上,分析辽宁海洋生态系统的恶化态势,主要体现在过度捕捞导致的海洋生物资源衰退,陆源污染、养殖污染和油类污染导致的海洋水体环境污染以及填海造地和海岸侵蚀等导致的海岸生态系统弱化。进而,从公地悲剧理论、环境库兹涅茨理论、外部性理论和产权理论4个维度做出具体的经济学阐释,阐明海洋生态系统恶化态势与经济开发行为之间的关系。