分层水体对表层辐照度比影响的蒙特卡罗分析

众多海洋观测数据表明,在真光层深度范围内,海水固有光学特性和光学有效组分的剖面分层分布是广泛存在的,而很多遥感反演模型的建立基于均一分布假设,尤其是在经验模型的建立中,往往只利用某一深度或各深度平均的光学有效组分浓度与水体光谱的统计关系。文章通过模拟平静水面水下光的辐射传输,分别研究了叶绿素、无机悬浮物浓度垂直分布结构对水下辐照度比的影响,并对比了两类分层水体权重函数等效浓度计算式及相应水下辐照度比,结果表明,对于分层水体,透射深度和层化强度是影响等效浓度值计算误差的主要因素,透射越深,表层层化越强,水体层化对水下辐照度比的影响就越大,但其计算误差也越大。Gondon等效浓度计算结果比较接近实际值,而Zaneveld计算式则高估了分层水体的等效浓度值。     

福建沿海地区水资源紧缺问题及其解决途径

本文针对福建沿海地区存在的水资源紧问题,通过对福沿海地区水资源数量,供需平衡的分析探讨了水资源紧缺问题存在的主要原因,并结合水资源利用的现状特征,进一步深入评述了现状利用中存在的问题,最后从可持续利用水资源的角度出发,重点讨论解决途径。     

褐菖鲉(Sebastiscus marmoratus)幼鱼生物学表型对体质量的影响效应

探究影响水产养殖动物体质量的关键生物学表型性状组合,进而揭示其体质量增长对策,对指导水产养殖动物的种质甄别与科学养殖具重要现实意义。随机选取象山西沪港海域板式网箱内养殖3个月的褐菖鲉幼鱼同生群个体60尾为研究对象,以全长(X₁)、体长(X₂)、体宽(X₃)、体高(X₄)、头宽(X₅)、侧线长(X₆)、尾柄高(X₇)、体质量(BW)、净体质量(NW)、内脏质量(W₁)、肠质量(W₂)、肝质量(W₃)、胃质量(W₄)、鳃质量(W₅)、心质量(W₆)为生物学测定指标,采用多元分析方法定量研究了体尺性状和称量性状对体质量的影响效应。结果表明:(1)经统计,所涉称量性状测定值较体尺性状更显离散,两者变异系数的波动范围分别为38.27%~89.86%和13.86%~17.78%,排序分别为W₄>W₁>W₆>W₂>W₅>W₃>NW>BW和X₃>X₄>X₆>X₅>X₂>X₇>X₁;经计算,消化脏器与内脏间的质量比呈W₃>W₄>W₂ (P<0.05);(2)相关分析显示,所涉体尺性状和称量性状均与BW呈极显著相关(P<0.01),两者相关系数波动范围分别为0.414~0.990和0.899~0.961,排序分别为NW>W₃>W₁>W₆>W₅>W₂>W₄和X₁>X₄>X₂>X₅>X₆>X₃>X₇;(3)经通径分析,被保留的称量性状组合和体尺性状组合的直接作用排序分别为NW>W₃>W₂>W₄>W₆和X₄>X₅>X₆>X₇;经决定程度分析和复相关分析,称量性状组合对BW的总决定系数和复相关指数均为0.989,体尺性状组合则均为0.961;(4)经偏回归分析,分别获得了基于称量性状组合和体尺性状组合的BW估算方程。研究结果可为褐菖鲉速生型种质遴选与科学养殖提供参考。     

海三棱藨草(Scirpus mariqueter)根系低分子量有机酸对根际沉积物重金属生物有效性的影响

应用等离子光谱仪(ICP)与高效液相色谱仪(HPLC)分别对海三棱藨草根际沉积物中重金属(Cu、Pb、Zn和Cd)不同化学形态含量和植物根系分泌物中常见低分子量有机酸进行了季节跟踪测定,分析了有机酸(柠檬酸、草酸、酒石酸、苹果酸、甲酸和乳酸)含量与重金属化学形态(可交换态、碳酸盐结合态、铁锰氧化物结合态、有机结合态和残渣态)的季节相关性。结果表明,柠檬酸、草酸和苹果酸含量与Cu和Pb的除残渣态外的其它4种形态含量呈正相关性,表明其能提高Cu和Pb生物有效性,与Zn的所有形态含量呈负相关性,降低了生物有效性;酒石酸、甲酸和乳酸含量与Cu和Pb的可交换态含量呈负相关性,而与其它形态含量相关性不明显,降低了生物有效性。与Zn的除残渣态外的其它4种形态含量呈正相关性,提高其生物有效性。而上述所有有机酸与Cd的各种化学形态相关性不明显。表明其对Cd的生物有效性影响不大。     

Performance investigation of a two-raft-type wave energy converter with hydraulic power take-off unit

Raft-type wave energy converter (WEC) is a multi-mode wave energy conversion device, using the relative pitch motion to drive its hydraulic power take-off (PTO) units for capturing energy from the ocean waves. The hydraulic PTO unit as its energy conversion module plays a significant role in storing large qualities of energy and making the output power smooth. However, most of the previous investigations on the raft-type WECs treat the hydraulic PTO unit as a linear PTO unit and do not consider the dynamics of the hydraulic circuit and components in their investigations. This paper is related to a two-raft-type WEC consisting of two hinged rafts and a hydraulic PTO unit. The aim of this paper is to make an understanding of the dynamics of the hydraulic PTO unit and how these affect the performance of the two-raft-type WEC. Therefore, a combined hydrodynamic and hydraulic PTO unit model is proposed to investigate and optimize the performance of the two-raft-type WEC; and based on the simulation of the combined model, the relationships between the optimal power capture ability, the optimal magnitude of the hydraulic PTO force and the wave states are numerically revealed. Results show that an approximately square wave type hydraulic PTO force is produced by the hydraulic PTO unit, which causes the performance of the two-raft-type WEC not to be sinusoidal and the energy capturing manner different from that of the device using a linear PTO unit; moreover, there is an optimal magnitude of the hydraulic PTO force for obtaining an optimal power capture ability, which can be achieved by adjusting the parameters of the hydraulic PTO unit; in regular waves, the optimal power capture ability as well as the optimal magnitude of the hydraulic PTO force normalized by the wave height presents little relationship with the wave height, mainly depends on the wave period; in irregular waves, the trends of the optimal power capture ability and the normalized optimal magnitude of the hydraulic PTO force against the peak wave periods at different significant wave heights are generally identical and show a good correlation. All means that the hydraulic PTO unit of the two-raft-type WEC can be tuned to the wave states, and these would provide a valuable guidance for the optimal design of its hydraulic PTO unit.     

极区冰基拖曳式海洋剖面浮标系统低功耗设计与实现

针对极区冰基拖曳式海洋剖面浮标长期稳定获取极区水文和气象数据的工作需求,进行了浮标系统的低功耗方案设计。该方案基于超低功耗51系列微处理器,根据最低功耗工作模式与最短工作时间原则,采用高效的电源管理机制对浮标系统各个部分的能量消耗进行合理的分配与管理,并应用了Argos卫星通讯模块ARGOS-3 PMT-RFM的BPSK调制低速数据传输模式,可有效降低浮标系统的整体能耗。该浮标在北极冰站上长达1年的运行情况表明该系统工作稳定,所采用的低功耗能量管理方案实现了浮标系统长期连续观测的需求。该浮标的成功试验和推广应用有助于极地研究人员更准确地分析海冰变化过程。     

Analysis of bycatch in the South African midwater trawl fishery for horse mackerel Trachurus capensis based on observer data

The South African midwater trawl fishery targets adult horse mackerel Trachurus capensis. The bulk of the catch is taken by a single freezer-trawler, the biggest fishing vessel operating in South African waters. As fishing takes place off the south coast in ecologically sensitive areas, there are concerns about the potential impacts of this fishing operation on non-target species. Fishing behaviour and bycatch of this fishery from 2004 to 2014 were investigated by analysing observer records with regard to catch composition, volume and temporal and spatial patterns. The midwater trawl fishery was estimated to have caught 25 415 tonnes annually, with a bycatch of 6.9% of the total catch, by weight. There are species overlaps with various fisheries, namely the demersal trawl, small-pelagic, line, shark longline and squid fisheries, yet the total bycatch estimates from this fishery are generally small relative to catches taken in the target fisheries. Bycatch species with the highest average annual catches were chub mackerel Scomber japonicus, redeye roundherring Etrumeus whiteheadi, ribbonfish Lepidopus caudatus and hake Merluccius spp. Large-fauna bycatch species included sunfish Mola mola as well as a number of CITES II- and IUCN-listed species, such as Cape fur seal Arctocephalus pusillus, dusky shark Carcharhinus obscurus, smooth hammerhead shark Sphyrna zygaena and thresher sharks Alopias spp. The 97.9% observer coverage is high and the 6.9% bycatch rate low compared to other South African fisheries; however, due to the large size of the individual hauls (average of 46.3 t), the average sampling rate of 1.56% is low. Our analyses suggest that bycatch in the South African midwater trawl fishery has been lower than in other South African fisheries and similar fisheries elsewhere, but due to the combination of high catch volumes and low sampling rates, estimation errors for rare species are high and there is a substantial risk of incidental unmonitored bycatch of rare large fauna and aggregations of small fauna. This could be mitigated by spatio-temporal management of this fishery, to avoid fishing in high-risk areas, and the introduction of an electronic monitoring programme.     

脊尾白虾(Exopalaemon carinicauda)体长和体重遗传力的估计

构建了脊尾白虾(Exopalaemon carinicauda)49个全同胞家系, 包括28个半同胞家系, 分别测定了30日龄和50日龄个体的体长和体重。利用SPSS软件的一般线性模型(GLM)过程, 计算表型变量的方差组分, 估计体长和体重性状的遗传力。结果表明, 脊尾白虾30日龄和50日龄体长的遗传力估计值分别在0.14—0.35和0.07—0.31之间, 脊尾白虾30日龄和50日龄体重的遗传力估计值分别在0.12—0.23和0.14—0.33之间; 雄性遗传方差组分均显著大于雌性遗传方差组分, 说明雄性遗传方差组分存在显著的父本效应。经过t检验, 父系半同胞、母系半同胞方差组分估计的遗传力均未达到显著水平, 全同胞方差组分估计的遗传力达到极显著水平。因此可以认为基于全同胞方差组分估计的遗传力是对脊尾白虾两个生长阶段体长和体重狭义遗传力的无偏估计值。本研究结果表明脊尾白虾体长和体重性状属于中度遗传力, 选择育种对于脊尾白虾早期生长的改良具有较大潜力。     

Quantitative characterization of connectivity and conductivity of sandstone carriers during secondary petroleum migration,applied to the Third Member of Eocene Shahejie Formation,Dongying Depression,Eastern China

Studies on migration pathways remain qualitative, albeit extensive quantification of migration forcing. In this study, hydrocarbon carriers are defined as carrier units and their corresponding carrier beds for the Third Member of Eocene Shahejie Formation in the Dongying Depression, Bohai Bay Basin, eastern China, on the basis of their lithofacies and physical properties, spatial relationships, and data availability; secondary migration conduits are then quantified. A carrier unit is defined as a stratigraphic unit that contains microscopically porous and permeable carrier beds and is covered by regional seals. The carrier beds are macroscopically and physically connected to each other within a carrier unit and are hydrodynamically connected during secondary migration. A method of quantifying sandstone carrier units using common physical properties is developed. First, a carrier unit containing potential carrier beds is identified on the basis of lithofacies and their lateral changes. Second, physical connectivity of sandstone carrier beds is assessed on the basis of percolation theory. Third, the hydrodynamic connectivity of a sandstone carrier unit is analyzed using effective parameters that may reflect the hydraulic circulation in the carrier unit. Last, the conductivity of a sandstone carrier bed is quantitatively characterized using appropriate physical property parameters. The results for sandstone carrier units in the Third Member of the Shahejie Formation are used in numerical models addressing Pleistocene secondary migration. The model results explain the discovered accumulation and hydrocarbon shows well; and the model predictions on exploration targets have been confirmed by drilling.     

基于图像技术的胶州湾浮游动物优势种体型参数与生物量转换关系研究

利用ZooScan图像扫描技术,建立胶州湾浮游动物优势种中华哲水蚤和强壮箭虫体长、面积和体积与干重之间的回归关系.比较了不同季节、不同参数之间的差异.结果表明,不同月份的回归关系之间无显著差异,在三个体型参数中,面积拟合生物量的程度最好,是利用图像方法估算生物量最佳参数.中华哲水蚤和强壮箭虫体型-生物量转换关系可以分别表示为:lgDW=1.611gA+ 1.69,lgDW=1.541gA+l.32.