Interannual variability in the biochemical composition of newly hatched larvae of the spider crab Maja brachydactyla (Decapoda,Majidae)

The spider crab Maja brachydactyla is an important commercial species in Europe and supports intensive fisheries in the NE Atlantic. A field survey was performed to assess long‐term and consecutive interannual (2005–2010) variation of the biochemical composition of newly hatched larvae of M. brachydactyla. Larval biochemical profiles differed significantly among years, with pronounced differences being recorded in 2010. Differences among batches of newly hatched larvae were mainly explained by the contribution of triacylglycerols and, to a lesser degree, by protein and lipid content. The use of different nutrition indices is discussed. The biochemical composition of newly hatched larvae from M. brachydactyla was highly variable, even though surveyed broodstock was obtained from the same local population and was always sampled during the same season. The unpredictable biochemical profiles of newly hatched larvae may condition their survival and recruitment. This largely overlooked aspect of larval variability should be considered in future fisheries management strategies and captive production of marine organisms that still rely on wild seeds.     

印度尼西亚海域潮波的数值研究

基于ROMS模式构建了模拟区域为(15.52°S-7.13°N,110.39°~134.15°E)水平分辨率为2′的潮波数值模式,分别模拟了印尼海域M2、S2、K1、O1四个主要分潮。模拟结果与29个卫星高度计交叠点上的调和常数进行比较,符合较好。M2分潮的振幅均方根差为3.4cm,迟角均方根差为5.9°;S2分潮的振幅均方根差为1.7cm,迟角均方根差为6.3°;K1分潮振幅均方根差为1.1cm,迟角均方根差为5.8°;O1分潮振幅均方根差为1.2cm,迟角均方根差为4.4°。M2、S2、K1、O1分潮向量均方根差分别为3.8cm、2.4cm、1.9cm和1.3cm,模拟结果的相对偏差在10%左右。根据计算结果分析了印尼海域的潮汐特征及潮能传播规律,结果显示:爪哇海以外的印尼海域主要为不规则半日潮区;全日潮潮能主要由太平洋传入印尼海域,而半日潮潮能则是从印度洋传入印尼海域。     

直驱式波浪能转换系统的研究和性能优化

A direct-drive wave energy conversion system based on a three-phase permanent magnet tubular linear generator （PMTLG） and a heaving buoy is proposed to convert wave energy into electrical energy. Sufficient experimental methods are adopted to compare the computer simulations, the validity of which is verified by the experiment results from a wave tank laboratory. In the experiment, the motion curves of heaving buoy are with small fluctuations, mainly caused by the PMTLG＇s detent force. For the reduction of these small fluctuations and a maximum operational efficiency of the direct-drive wave energy conversion system, the PMTLG＇s detent force minimization technique and the heaving buoy optimization will be discussed. It is discovered that the operational efficiency of the direct-drive wave energy conversion system increases dramatically after optimization. The experiment and optimization results will provide useful reference for the future research on ocean wave energy conversion system.     

Design of a hydraulic power take-off system for the wave energy device with an inverse pendulum

This paper describes a dual-stroke acting hydraulic power take-off （PTO） system employed in the wave energy converter （WEC） with an inverse pendulum. The hydraulic PTO converts slow irregular reciprocating wave motions to relatively smooth, fast rotation of an electrical generator. The design of the hydraulic PTO system and its control are critical to maximize the generated power. A time domain simulation study and the laboratory experiment of the full-scale beach test are presented. The results of the simulation and laboratory experiments including their comparison at full-scale are also presented, which have validated the rationality of the design and the reliability of some key components of the prototype of the WEC with an inverse pendulum with the dual-stroke acting hydraulic PTO system.     

Effect of under connected plates on the hydrodynamic efficiency of the floating breakwater

In this paper, the hydrodynamic efficiency of a floating breakwater system is experimentally studied by use of physical models. Regular waves with wide ranges of wave heights and periods are tested. The efficiency of the breakwater is presented as a function of the wave transmission, reflection, and energy dissipation coefficients. Different parameters affecting the breakwater efficiency are investigated, e.g. the number of the under connected vertical plates, the length of the mooring wire, and the wave length. It is found that, the transmission coefficient kt decreases with the increase of the relative breakwater width B/L, the number of plates n and the relative wire length l/h, while the reflection coefficient kr takes the opposite trend. Therefore, it is possible to achieve kt values smaller than 0.25 and kr values larger than 0.80 when B/L is larger than 0.25 for the case of l/h-1.5 and n=4. In addition, empirical equations used for estimating the transmission and reflection coefficients are developed by using the dimensionless analysis, regression analysis and measured data and verified by different theoretical and experimental results.     

The co-location of offshore windfarms and decapod fisheries in the UK: Constraints and opportunities

The offshore wind sector in the UK is expanding rapidly and is set to occupy significant areas of the coastal zone, making it necessary to explore the potential for co-location with other economic activities. The presence of turbine foundations introduces hard substrates into areas previously dominated by soft sediments, implying that artificial reef effects may occur, with potential benefits for fisheries. This review focuses on the possibilities for locating fisheries for two commercially important decapods, the brown crab Cancer pagurus and the European lobster Homarus gammarus, within offshore wind farms.Existing understanding of habitat use by C. pagurus and H. gammarus suggests that turbine foundations have the potential to act as artificial reefs, although the responses of these species to noise and electromagnetic fields are poorly understood. Offshore wind farm monitoring programmes provide very limited information, but do suggest that adult C. pagurus associate with turbine foundations, which may also serve as nursery areas. There was insufficient deployment and monitoring of rock armouring to draw conclusions about the association of H. gammarus with offshore wind farm foundations. The limited information currently available demonstrates the need for further research into the ecological and socio-economic issues surrounding fishery co-location potential.     

基于LAGFD-WAM海浪数值模式的海南万宁近海波浪能资源评估

利用1991—2010年的NCEP再分析风场驱动LAGFD-WAM海浪数值模式,通过数值后报方法,对海南万宁近海海域近20年的波浪场进行了逐时数值模拟,数值模拟结果和实测结果对比的一致性良好。在数值后报数据的基础上计算了万宁近海波浪能流密度和能流密度变异系数,并对其年内变化特点、区域分布特征和稳定性进行了分析。万宁近海年均波浪能流密度3—10 k W/m,属于波浪能资源可利用区和较丰富区。年内各月月均能流密度差别较大,12月波浪能资源最好,5月波浪能资源最差。秋季(9—11月)和冬季(12—2月)月均波浪能流密度分别为5—24 k W/m和6—29 k W/m,春季(3—5月)和夏季(6—8月)分别为3—7 k W/m和1—6 k W/m。地形对波浪能量的辐聚作用明显,受岬角、岛屿、海底陡坡等因素影响,大洲岛、白鞍岛周边、大花角附近及白鞍岛以北部分近岸区域形成波浪能富集区。除9月外,年内其他时段能流密度变异系数都在2.8以下,9月能流密度变异系数在3.0—5.9之间。     

海上试验场潮流能发电装置综合测试与评价方法分析(英文)

开展潮流能装置实海况试验、检测与评价方法研究,对海洋高科技成果的转化、海洋可再生能源开发提供了科学、有效的技术保障。文章通过对潮流能装置的功率输出特性、年发电量、能量转换效率三项核心指标进行分析,提出指标的测试内容和评价方法,为实现潮流能海上试验与测试场建设提供技术依据;并根据对海上风电场的研究,提出了海上试验场潮流能装置的电能质量测试与评估方法;给出潮流能装置安全准入的测试内容,全面评估试验场潮流能装置的运行状态。     

高原东南缘大气近地层湍能特征与边界层动力、热力结构相关特征

基于云南省大理2008年3、5、7月GPS加密探空试验时段(14和02时)资料,结合边界层铁塔综合观测资料,采用温度梯度法、逆温强度法和涡动相关法分别计算高原东南缘对流边界层(convective boundary layer,CBL)及稳定边界层(stable boundary layer,SBL)顶高度,通过计算获取感热通量、潜热通量、湍流动能、切变项以及浮力项与大气动力、热力过程垂直相关特征综合分析,可发现湍能方程中浮力项、感热、潜热通量与NCEP再分析资料计算获取的大气视热源相关特征显著,这某种程度反映了高原东南缘近地层大气湍流动量、热量输送对低层大气视热源Q_1的重要贡献。低层视热源Q_1亦表现出与湍能方程分量类似的日变化周期,此特征反映了高原东南缘大气热源变化与下垫面水热过程及其湍流输送日变化密切相关;浮力项与湍能等项对大气低层热源与涡动特征、热力混合结构的形成有重要作用;低层大气视热源、水汽汇均与边界层高度有显著相关,综合分析结果某种程度描述了青藏高原东南缘近地层湍流动量、热量输送状况与低层大气热源,热力混合边界层结构的综合相关物理图像,初步探索了高原东南缘对流活跃区大气湍流运动与大气动力、热力过程相互作用特征。研究表明近地层湍流通量变化某种程度可反映未来局地大气视热源垂直结构变化的"强信号"特征。本文上述研究结论也可启发我们进一步关注近地层湍流通量异常变化特征及其对局地降水过程大气热源结构演变的影响问题。     

基于灰色定权聚类的江苏省工业节能减排评价研究

采用灰色定权聚类分析法,对江苏省近年来的工业节能减排情况进行评价.结果表明：2000年以及2009-2011年的节能减排效果较好,2002-2008年的节能减排效果一般,2001年的节能减排效果较差.另外,还结合各项指标对评价结果进行分析,并有针对性地提出有关江苏省节能减排措施的建议.