北黄海潮流、余流垂直结构及其季节变化

基于对2006年夏季与2007年冬季在123.51°E,38.00°N的各1个月潮流和水位观测数据的分析,发现夏季余流呈现两层结构,上层流向为西北,下层流向东南,并且当大潮日期附近,在跃层附近深度存在若干流速较强的水层;冬季余流除了个别层以外基本上均为西北向流入北黄海,从中可以看到风场改变所引发的异常增减水和强流出现。对潮流椭圆的分析表明,半日潮族分潮流的最大流向自夏季至冬季存在着顺时针的旋转,旋转角大约为16(°)～18(°),并且夏季半日潮族随深度顺时针,全日潮族逆时针旋转,而冬季基本上上下一致。     

噻唑烷酸对肝组织GSH含量的影响及其作用机制的研究

建立丁胱亚磺酰亚胺(L-Buthionine Sulfoximine,BSO)排空小鼠肝组织谷胱甘肽(Glutathione,GSH)模型,研究噻唑烷酸(N-acetyl-glucosamine-thiazolidine-4(R)-carboxylic acid,GlcNAcCys)提高肝组织GSH含量,保护肝脏免受外源性毒物、药物损伤的可能机制。正常对照组小鼠腹腔注射生理盐水,BSO组及GlcNAcCys不同剂量组小鼠注射BSO(6mmol/kg体质量,i.p.)。2 h后,正常对照组和BSO组注射生理盐水,GlcNAcCys低、中、高剂量组分别注射不同剂量的GlcNAcCys(200、4009、00 mg/kg体质量)。6 h后,用Ellman’s法测定肝匀浆总巯基(Total Sulfhydryl,T-SH)含量;荧光分光光度法测定GSH含量;用试剂盒检测肝匀浆中谷胱甘肽还原酶(Glutathione Reductase,GR)和谷胱甘肽-S转移酶(Glutathione S-transferase,GST)活性;RT-PCR法检测谷氨酰半胱氨酸连接酶催化亚基(Glutamyl-L-cysteine Ligase,GCL)基因表达。GlcNAcCys能够提高肝匀浆中T-SH和GSH含量,增强抗氧化酶GR、GST活性,RT-PCR结果显示,GlcNAcCys能够诱导GCL mRNA的表达。GlcNAcCys能够提高肝组织T-SH、GSH的含量,增强GST、GR酶活力,增强肝脏的解毒功能,保护肝脏免受毒性中间代谢物的损伤。GlcNAcCys提高肝组织T-SH、GSH含量的机制与其诱导GCLmRNA的表达有关。     

温度对赤潮异弯藻生长速率及细胞体积和生化组成影响的研究

在实验室条件下,研究了温度对赤潮异弯藻生长速率、细胞体积和生化组成的影响。结果表明,赤潮异弯藻在10~30℃之间均能正常生长,25℃时生长速率最高,25℃为其最适生长温度;赤潮异弯藻的细胞体积随着温度的升高大致呈逐渐减小的趋势,10℃时细胞体积最大(823.89μm3),25℃时细胞体积最小(387.98μm3)。进一步分析表明,赤潮异弯藻生长速率与细胞体积(对数值)呈显著的负相关关系(P0.05)。在10~25℃之间,赤潮异弯藻单个细胞的碳、氮含量随着温度的升高呈逐渐减少的趋势,其单位体积细胞的碳、氮含量却呈单峰变化(15℃时结果为峰值)现象;叶绿素a含量在单个细胞和单位体积细胞两个层次上随温度的变化趋势一致,即其在整个温度区间内随着温度的升高均呈逐渐增加的趋势。赤潮异弯藻细胞C∶Chl a和N∶Chl a随着温度的升高呈先减小后增加的趋势,均在10℃时最大,在25℃时最小。     

南海西北部沉积物捕获器中颗石藻通量和属种组成变化记录

本文利用沉积物捕获器回收的连续时间序列沉降颗粒物样品,研究了南海西北部海南岸外陆坡外缘海域颗石藻的通量和属种组成变化及其环境意义。研究发现,东亚夏季风引起的海南岸外上升流以及冬季风导致的混合层深度增加都会刺激该区域颗石藻的生长,其中夏季上升流的影响尤为显著。从颗石粒属种组成来看,Florisphaera profunda是南海西北部中深层(1 000m)水体中主要的颗石粒优势种,此外Emiliania huxleyi,Gephyrocapsa oceanica和Gephyrocaps ericsonii等属种含量也颇高。然而在将颗石粒折算成颗石球数量后,Emiliania huxleyi则成为主要优势种。沉积物捕获器中F.profunda的相对百分含量与颗石粒总通量呈显著的负相关,表明F.profunda的相对含量与总的颗石藻生产力有着密切联系。本结果对于利用沉积物中的颗石藻记录,尤其是F.profunda相对含量变化,恢复和重建古海洋环境尤其是古海洋生产力的研究提供了直接的理论证据。     

2009年冬、夏季南海北部超微型浮游生物的分布特征及其环境相关分析

2009年2月(冬季)和8月(夏季)在南海北部海域(nSCS)采用流式细胞术对聚球藻、原绿球藻、超微型光合真核生物3类超微型光合浮游生物和异养浮游细菌的丰度和碳生物量的时空分布特征进行了研究,并分析了其与环境因子之间的关系。结果表明,夏季聚球藻和原绿球藻的平均丰度高于冬季,超微型光合真核生物和异养浮游细菌的丰度反之,为冬季高于夏季。聚球藻、超微型光合真核生物和异养浮游细菌在富营养的近岸陆架海域丰度较高,而原绿球藻高丰度则出现在陆坡开阔海域。在垂直分布上,聚球藻主要分布在跃层以上,跃层以下丰度迅速降低;原绿球藻高丰度主要出现在真光层底部;超微型光合真核生物在水层中的高值同样出现在真光层底部,且与Pico级份叶绿素a浓度分布一致;异养浮游细菌在水体中的分布与聚球藻类似。这些分布格局的差异,取决于环境条件的变化和4类超微型浮游生物生态生理适应性的差异。在超微型光合浮游生物群落中,各类群碳生物量的贡献因季节和海域类型的不同而发生变化:聚球藻在夏季近岸陆架区占超微型光合浮游生物总碳生物量的41%,原绿球藻在陆坡开阔海成为主要贡献者(50%),超微型光合真核生物碳生物量以冬季为高(在近岸陆架区占比68%)。冬、夏季异养浮游细菌碳生物量均高于超微型光合浮游生物碳生物量。     

南黄海秋季浮游病毒丰度分布及其与宿主和环境因子的相关性研究

利用流式细胞仪对南黄海秋季浮游病毒丰度在水平分布和垂直分布上的特征进行了研究,并分析了浮游病毒丰度与异养细菌、微微型浮游植物等宿主丰度以及环境因子的相关性.结果表明,该海区秋季浮游病毒丰度在(2.22×106)-(1.60× 107)ind/ml之间,平均值8.32×106ind/ml.病毒丰度在调查海域的东北和中南部海域出现高值区,在西南部出现低值区,且浮游病毒丰度与异养细菌丰度的平面分布趋势较一致.在表层、中层和底层水体,浮游病毒丰度平均值分别为8.63×106、7.83×106、8.49×106ind/ml,表层和底层丰度无显著差异,但均高于中层(P＜0.05).相关性分析表明,浮游病毒丰度与异养细菌丰度、VBR呈显著正相关(P＜0.01),与微微型真核浮游植物丰度呈显著负相关(P＜0.05),与聚球藻、水深、水温、盐度、溶氧、叶绿素a浓度无明显相关性(P＞0.05).     

南黄海地震资料叠前去噪技术应用

南黄海盆地位于下扬子地台东北部,是一个由多期、多类型盆地叠加的复合残留盆地,平均水深约为50 m。工区内地震资料信噪比较低,干扰波类型较多,主要有涌浪、电缆和水鸟等产生的随机噪声,线性噪声和船干扰等相干噪声。通过系统分析噪声在振幅、频率方面的特征,以及噪声产生的机制,分别在不同域采用多种压制方法,主要采用分频分时振幅衰减技术去除异常振幅噪声,f-x域相干噪音方法压制低速线性噪声干扰,外部噪音模型法压制高速线性噪声,τ-p域切除法去除直达波干 扰,以及采用fxy域预测误差方法压制船干扰噪声等。通过以上叠前多域去噪技术方法,在尽量不损害有效信号的情况下,对南黄海地震数据的各种噪声进行很好的压制。     

Growth stimulation and inhibition of natural phytoplankton communities by model organic ligands in the western subarctic Pacific

The influence of organic ligands on natural phytoplankton growth was investigated in high-nitrate low-chlorophyll (HNLC) waters and during a phytoplankton bloom induced by a mesoscale iron enrichment experiment (SEEDS II) in the western subarctic Pacific. The growth responses of the phytoplankton in the treatments with iron complexed with model ligand were compared with those with inorganic iron or a control. Desferrioxamine B and protoporphyrin IX were used as models for hydroxamate-type siderophore and tetrapyrrole-type cell breakdown ligand, respectively. In the HNLC water, iron associated with protoporphyrin IX especially stimulated smaller phytoplankton (<10 μm) growth, 1.5-fold more than did inorganic iron. Surprisingly, only the addition of protoporphyrin IX stimulated small phytoplankton growth, suggesting that these cell breakdown ligands might be more bioavailable for them. The protoporphyrin IX’s stimulatory effect on small phytoplankton was not observed during bloom decline phase. The growth of phytoplankton was inhibited in the treatment with desferrioxamine B-complexed iron, suggesting its low bioavailability for the natural phytoplankton community. Its inhibitory effects were particularly pronounced in pico-eukaryotic phytoplankton. During the iron-induced bloom, the phytoplankton’s iron-stress response gradually increased with the desferrioxamine B concentration, suggesting that the competition for iron complexation between natural ligands and desferrioxamine B affected phytoplankton growth. However, the pico-eukaryotes did seem better able to utilize the desferrioxamine B-complexed iron during the bloom-developing phase. These results indicate that the iron bioavailability for phytoplankton differs between bloom-developing and bloom-decline phases.     

Response of bedload transport, submarine topography, and dune internal structures to typhoon processes off Dongfang coast in the Beibu Gulf

Bedload sediment transport was estimated by the SEDTRANS96 model based on three-day hydrodynamics data obtained off the Dongfang coast in the Beibu Gulf during Typhoon Ketsana in September 2009. Bedforms on the sea floor off the Dongfang coast and internal structures of a typical dune were interpreted to evaluate storm influences on individual dunes and the dune field. Results indicated that flow forcings and related bedload transport were both strengthened significantly due to Typhoon Ketsana. The measurements and modeling results, which mainly included three different stages, presented noticeable phasic variation. The three stages were dominated by tidal current (Period Ⅰ), tidal current combined with wind-induced waves (Period Ⅱ), and swells combined with tidal current and seaward flows (Period Ⅲ). This phasic variation could be a common trait of hydrodynamics due to typhoons moving westwardly to the south of Hainan Island and Beibu Gulf in South China Sea. Results indicated that the maximum bedload transport rate for every burst in Period Ⅲ was almost 100 times larger than that in Period I and was ten times larger than that in Period II. However, the short-term increase in bedload transport induced by storms like Ketsana did not change the long-term evolution of dune morphology. Evidence was given by the internal structures of a typical dune, which revealed renewed modification under subsequent moderate conditions after storm erosion. Instead, storms may influence at different scales and regional allocation of sand dunes in some large areas because changes of the sea floor in large scales can hardly be recovered. More surveys during and after storm passage are also needed to document the level of positive contribution to forward migration.     

天然气水合物勘查相关技术集成研发进展

天然气水合物作为21世纪新型潜在能源,在新一轮地质调查背景下,国家加大了天然气水合物勘查技术的研发投入。通过跟踪国外天然气水合物调查前沿技术,结合我国实际勘查需求,在对声学深拖探测系统、可控源海洋电磁探测技术、现场检测及原位监测等技术现状进行分析的基础上,开展了相应的研发工作,重点介绍了各技术装备研发工作进展及目前取得的阶段成果,并提出了下一步的工作要点。