南黄海夏季微微型浮游植物丰度的分布

2008年8月中韩合作对南黄海生态系统进行了整体调查,调查站位共计37个。利用流式细胞仪测定了南黄海微微型浮游植物丰度,结合理化环境因子,分析了它们在夏季南黄海的分布特征。所测微微型真核浮游植物丰度平均值为1.9×103个/mL,最大值为2.4×104个/mL;聚球藻丰度平均值为5.3×104个/mL,最大值为5.1×105个/mL;从河口近岸到南黄海中部的宽阔海域,随着环境因子的变化,微微型浮游植物在各海区的分布明显不同,表现为河口近岸区域丰度大,离岸丰度小的特点;各站位丰度垂直分布主要趋势是上大下小,在跃层突出。根据分布趋势,聚球藻可分为两种垂直分布类型,微微型真核浮游植物分为三种。这些分布差异源于长江冲淡水和黄海冷水团的影响。     

虾夷扇贝毒素对Hela细胞凋亡诱导作用的初步研究

以Hela细胞为研究对象,通过四氮唑蓝(MTT)比色法、光学显微镜观察、Giemsa染色以及DNA凝胶电泳,研究了几种产YTXs的赤潮藻种多边舌甲藻(Lingulodinium polyedrum)CCMP1931,具刺膝沟藻(Gonyaulax spinifera)CCMP409,网状原角藻(Protoceratium reticulatum)CCMP2776粗提液对细胞的凋亡诱导作用,并通过LC-MS/MS分析各粗提液的成分及毒性大小。结果表明:CCMP1931、CCMP409、CCMP2776均对Hela细胞有毒性作用,能引起细胞凋亡事件,同时,分析其毒素成分发现,3种藻均能产生YTX及其衍生物,且相对毒力大小为CCMP2776CCMP1931CC-MP409。     

Numerical and Experimental Study of Blockage Effect Correction Method in Towing Tank

When a ship model test is performed in a tank, particularly when the tank is small and the ship model is relatively large, the blockage effect will inevitably occur. With increased ship model scale and speed, the blockage effect becomes more obvious and must be corrected. In this study, the KRISO 3600 TEU Container Ship(KCS) is taken as a model and computational fluid dynamics techniques and ship resistance tests are applied to explore the mechanism and correction method of the blockage effect. By considering the degrees of freedom of the sinkage and trim, the resistance of the ship model is calculated in the infinite domain and for blockage ratios of 1.5%, 1.8%, 2.2%, and3.0%. Through analysis of the free surface, pressure distribution, and flow field around the ship model, the action law of the blockage effect is studied. The Scott formula and mean flow correction formula based on the average cross sectional area are recommended as the main correction methods, and these formulas are improved using a factor for the return flow velocity correction based on comparison of the modified results given by different formulas. This modification method is verified by resistance test data obtained from three ship models with different scale ratios.     

Upper Miocene–Pliocene provenance evolution of the Central Canyon in northwestern South China Sea

Provenance studies of the Central Canyon, Qiongdongnan Basin has provided significant insights into paleographic and sedimentology research of the South China Sea (SCS). A suite of geochemical approaches mainly including rare earth elemental (REE) analysis and detrital zircon U–Pb dating has been systematically applied to the “source-to-sink” system involving our upper Miocene–Pliocene Central Canyon sediments and surrounding potential source areas. Based on samples tracing the entire course of the Central Canyon, REE distribution patterns indicate that the western channel was generally characterized by positive Eu anomalies in larger proportion, in contrast to the dominance of negative values of its eastern side during late Miocene–Pliocene. Additionally, for the whole canyon and farther regions of Qiongdongnan Basin, the number of samples bearing negative Eu anomalies tended to increase within younger geological strata. On the other hand, U–Pb geochronology results suggest a wide Proterozoic to Mesozoic age range with peak complexity in Yanshanian, Indosinian, Caledonian and Jinningian periods. However in detail, age combination of most western samples displayed older-age signatures than the eastern. To make it more evidently, western boreholes of the Central Canyon are mainly characterized with confined Indosinian and Caledonian clusters which show great comparability with mafic-to-ultramafic source of Kontum Massif of Central Vietnam, while eastern samples largely bear with distinguishable Yanshanian and Indosinian peaks which more resemble with Hainan Island. Based on geochemistry and geochronology analyses, two significant suppliers and sedimentary infilling processes are generated: (1) the Indosinian collision orogenic belt in central-northern Vietnam, Indochina has ever played significant role in Central Canyon sedimentary evolution, (2) Hainan Island once as a typical provenance restricted within eastern Central Canyon, has been enlarging its influence into the whole channel, even into the farther western regions of Qiongdongnan Basin.

     

太平洋徐福海山富钴结壳稀土元素和铂族元素赋存状态研究

利用等离子体发射光谱法、等离子体质谱法以及相态分析手段,对太平洋徐福海山富钴结壳稀土和铂族元素地球化学特征、赋存状态及富集机制进行研究。结果表明,富钴结壳稀土和铂族元素明显富集,其稀土总量为1 842～2 854 μg/g,铂族总量为144～1 180 ng/g,老壳层中稀土和铂族元素含量明显高于新壳层,这可能与老壳层发生磷酸盐化作用有关。轻稀土元素含量明显高于重稀土元素含量,呈现Ce正异常而Eu无异常,具有明显Ce富集特征。铂族元素之间发生了明显分异作用,PPGE含量明显高于IPGE,表现出明显Pt正异常而Pd负异常,具有明显Pt富集而Pd亏损特征。稀土元素赋存状态显示,新壳层中稀土元素主要赋存于铁氧化物相,其富集比例为65.40%～70.05%,老壳层中稀土元素主要赋存于残渣态,富集比例为62.27%～65.77%,这可能与残渣态中磷酸盐有关。铂族元素赋存状态显示,新壳层和老壳层中铂族元素都主要赋存于铁氧化物相,其富集比例为63.66%～69.51%,残渣态(29.20%～34.68%)对铂族元素也有一定的富集能力。富钴结壳稀土和铂族元素的富集推测为铁氧化物胶体粒子的吸附作用,受海水氧化性环境影响,可溶性Ce³⁺和Pt²⁺分别被氧化成不溶性Ce⁴⁺和Pt⁴⁺,沉淀被吸附到铁氧化物相中,从而造成富钴结壳稀土和铂族元素的富集。     

Shear Strength and Dilatancy of Calcareous Sand in the South China Sea

The shear strength and dilatancy of typical uncemented calcareous sand from the South China Sea are investigated by soil lab tests. According to drained triaxial tests at various relative densities and confining stresses, it is found that the constant volume friction angle is approximated as 39° and the traditional Bolton’s equations can be modified to estimate the peak friction angle and dilation angle. The reliability of the equation proposed for the peak friction angle is verified in terms of calcareous sands from more onshore and offshore sites worldwide, while the errors of the predicted dilation angles scatter in a relatively large range. Totally, the dilation angles of sands in the South China Sea are estimated by the equation presented with an error of ±30%. The peak friction angle measured by the undrained is similar to that by the drained tests as the relative density smaller than 60%, while the former is slightly lower for denser samples.

     

莆田围填海工程对岸线变迁及海岸环境的影响研究

文章运用 ArcGIS10.5软件的DSAS模块的端点变化率、线性回归率等算法,以莆田市 1984年、1994年、2004年、2010年、2014年和2019年6个时期的google遥感影像图（Landsat卫星）为数据源,分析莆田30余年来围海、填海工程及其他岸线类型的变迁过程。结合历史文献资料研究发现:①1984—2004年,围填海工程基本以围海养殖和围海盐业生产为主,胜利、澄峰、后海、东峤围海垦区占围海工程90%以上;②2004—2014年,填海造地工程飞速发展,临港产业园、妈祖城、东吴港区、石门澳等大面积区域性填海面积约60 km2,约占全市填海面积的93%;③近5年来,大批围海工程转产转型,围海面积逐年减少,生态修复岸线和砂质岸线迅速增长,海岸保护能力不断升级。莆田围填海工程建设提升了莆田海洋经济社会的发展水平,增加了海洋经济产值,适应了城市发展需求,但海岸保护功能降低、纳潮量减少、生物多样性损伤、水质恶化等海洋生态环境问题日益突出。随着生态海堤、蓝色海湾等海洋修复工程的实施,改善了海岸防护工程的功能体系,提升了海岸带生态环境自适应能力,为推进海岸带生态修复工程的实施提供科学依据。     

人工鱼礁区三种习见肉食性软体动物营养生态位研究

以小黑山岛人工鱼礁区为研究区,利用稳定同位素技术分析该海域三种习见肉食性软体动物长蛸（Octopus minor）、短蛸（Octopus fangsiao）和脉红螺（Papana venosa）的营养生态位,进而判断物种种间关系。分析结果显示：食物来源范围由大到小依次为长蛸、脉红螺、短蛸,其中长蛸食物来源包含短蛸食物来源范围,但脉红螺与两种蛸类食物来源无交叉;营养级由高到低依次为长蛸、短蛸、脉红螺。长蛸与短蛸营养生态位重叠比例较高,存在明显的竞争关系,与短蛸相比,长蛸营养级更高,食物来源范围更广,在竞争中处于优势地位;脉红螺的营养生态位与两种蛸类无重叠,其营养级比两种蛸类更低且无捕食或竞争关系。     

智利大西洋鲑养殖业的成功经验及启示

智利作为海水养殖大国,海水养殖总量一直位于世界前列,其中大西洋鲑养殖业是智利渔业的支柱产业,其成功发展离不开政府的支持、健全的法律体系保障、成熟的产业体系和先进的养殖技术等。文章主要采用描述性统计分析和对比分析的方法,在总结智利大西洋鲑养殖经验的基础上,针对我国海水养殖业存在的问题提出提高苗种质量、完善法律制度保障、提高组织化程度以及重视技术创新等一系列建议,以期促进我国海水养殖业的发展。