晚第四纪冲绳海槽北段CaCO3含量的时空变化及其控制因素

对取自冲绳海槽北段的6个沉积岩心进行了CaCO3含量、粒度和铀系同位素分析，结合氧同位素数据和海槽其他钻孔的相应结果，探讨了冲绳海槽北部晚第四纪以来CaCO3含量的垂向与横向变化特征。结果表明，冲绳海槽北段沉积总体上表现为全新世CaCO3含量高、晚更新世CaCO3含量低的“大西洋型”碳酸盐演化特征，但冲绳海槽北段和中部的碳酸盐演化特征并不一致，海槽内西坡、槽底和东坡的不同部位其演化特征也存在较大差异。碳酸盐含量的变化与沉积物粒度特征密切相关，晚第四纪冲绳海槽碳酸盐演化的时空差异是多种因素相互作用的结果。     

锶诱导的氧化胁迫对叉鞭金藻(Dicrateria inornata)的影响

采用不同浓度的锶胁迫方法研究了叉鞭金藻生长、叶绿素、MDA含量及三种抗氧化酶SOD、CAT、GPX活性的变化。结果表明，在实验设计的各种Sr^2 浓度内叉鞭金藻均能生长，但Sr^2 浓度较高时生长受到不同程度的抑制，细胞数量比对照组分别减少15．9％和51．0％；叉鞭金藻中叶绿素含量随着Sr^2 浓度的升高而降低，呈负相关关系；叉鞭金藻中MDA含量在较低Sr^2 浓度下稍呈下降趋势，但与对照组相比并无显著差异，而在23．04mmol／L Sr^2 浓度时是对照的1．25倍；低Sr^2 浓度时，叉鞭金藻中蛋白质含量没有大的变化，当浓度超过5．76mmol／L时则引起蛋白质含量下降；叉鞭金藻中抗氧化酶SOD在低Sr^2 时分别降低12．5％、7．5％和9．5％，高Sr^2 时显著升高，为对照组的85．7％；CAT、GPX活性在低Sr^2 浓度时差别不大，但当浓度为23．04mmol／L时升高显著，比对照组分别增加了19．8％和74．4％。     

Scaling analysis of deposition from turbidity currents

Many oil-bearing sedimentary deposits are formed by the settling of particles from turbidity currents. Modeling sedimentary processes that form these turbidites enables the calculation of properties such as extent, depth, porosity and permeability of hydrocarbon-bearing reservoirs. This paper estimates the extent and thickness of turbidites from the initial conditions of the turbidity flow. This is achieved by the application of scaling analysis of the partial differential equations that govern the dynamics of and deposition from turbidity currents. We apply the results of scaling analysis to five modern submarine fans. The predicted and actual values of the dimensions of the fan deposits match well. We then compare the derived results against tabulated sizes of ancient turbidites. The comparisons are good as long as we correctly identify the flow regimes in which the deposition took place. The good agreements observed in the two cases show that the estimates obtained using scaling analysis can provide useful first-guess values for the dimensions of the deposits.     

冲绳海槽北部表层沉积物中底栖有孔虫分布及其与海洋环境的关系

对1999年6月采自冲绳海槽北部的62个表层沉积物样品进行了底栖有孔虫分析。研究表明，该区属种多为中外陆架和上部陆坡常见底栖有孔虫，其中Cibicides pseudoungerianus在研究区域内广泛分布。底栖有孔虫群落明显受研究区水团的制约，该区底栖有孔虫Q型因子分析反映的4个组合分别对应不同的水团影响：组合1以Cibicides pseudoungerianus、Uvigerina sp.、Ammonia ketienziensis、Textularia pseudocarinata为主，代表陆架混合水团影响环境；组合2以Uvigerina peregrina、Beregrina、Bulimina mexicana、Bulimina submarginata、Globocassidulina subglobosa为主，代表黑潮暖流中层水影响下的环境；组合3以喜营养分子Bulimina marginata和Bolivina robusta为主，代表冷涡沉积和上升流沉积区的环境；组合4以Cibicides pseudoungerianus、Globocassidulina subglobosa为主，代表了对马暖流水团影响下的环境，其中水团的氧含量水平和营养状况是影响底栖有孔虫组合变化的主要因素。底栖有孔虫的丰度从西往东依次出现两个丰度高值带，一个位于研究区西部100—140m水深的陆架区，另一个位于400—600m水深的上陆坡，后者可能反映了冲绳海槽大陆坡普遍发育的陆坡上升流现象。     

南海南部晚中新世的放射虫及其环境探讨

南海是东亚古季风产物的主要沉积盆地，保存着比陆地更加完整和连续的沉积记录。详细分析了ODP1143号钻井晚中新世的放射虫化石群，主要根据标志种Diartus petterssoni,D.hughesi和Stichocorys delmontensis等的分布特征，分别建立了南海南部晚中新世的RN6，RN7和RN8等3个放射虫化石带，并讨论了其地层年龄。探讨了以地层中放射虫的丰度变化特征等在南海南部作为东亚古夏季风活动替代性指标的可能性，初步说明东亚古夏季风可能早于8．7Ma B.P．出现，约在8．24Ma B.P.强化达到高峰，认为与印度季风的出现几乎同步或略早。     

冲绳海槽北部表层沉积物中的钙质超微化石及其环境特征

为探讨冲绳海槽表层沉积物中钙质超微化石的分布规律及其影响因素 ,对海槽北部槽坡区 ( 2 9°5 8.33′— 31°31 .2 3′N ,1 2 7°39.5 5′— 1 2 8°5 9.61′E) 34个表层样品进行了分析和研究。共发现 35种钙质超微化石 ,其中优势种为Gephyrocapsaoceanica、Emilianiahuxleyi和Florisphaeraprofun da ;G .oceanica、E .huxleyi等的百分含量变化和特征属种U .tenuis的出现 ,表明该区钙质超微化石组合面貌与东海外陆架相似 ,和东海及南海都属于北太平洋中央水团组合。G .oceanica的含量与海水营养盐存在一定的关系 ,但两者之间并不存在明显的正相关性 ;暖水分子U .irregularis、U .sibogae和O .fragilis的较高含量和冷水分子G .caribbeanica和Calcidiscusleptoporus的较低含量 ,进一步反映该区钙质超微化石的分布受到黑潮及对马暖流的影响 ,其中温度、盐度和表层海水结构性质 ,如海水透明度等因素可能为主要控制因素。     

Effects of chemical ecological adjustment and control experiment on phytoplankton community in the Aoshan Bay

There is a low nutrient level in the Aoshan Bay. In June 1999, the chemical adjustmentand control experiment was made in the Aoshan Bay. Following tracts investigation was carried out before the experiment and on the 1st, 2nd, 4th, 5th, 6th and 45th day/after the experiment. While the variance of amount of phytoplankton, the replacement of superior species and the species composition of phytoplankton were researched. The results show that the amount of phytoplankton in the Aoshan Bay rises gradually after the experiment. Ceratium macroceros Cleve of pyrophyta was the dominant species before the experiment, its dominant index was 37.7％. Six days after the experiment, its dominant index dropped to 17.6％ . Meanwhile the dominant index of Asterionella japanics Cleve rose from 7.1％ to 39.2％ , it became the first dominant species. Forty-five days after the experiment, the amount of phytoplankton in the Aoshan Bay was 5.15 to 137.32 times more than that in 1997.     

脱盐处理对钢样-砂浆界面微观结构的影响

运用扫描电镜(SEM)和X-射线衍射(XRD)技术研究了电化学脱盐处理对钢样-砂浆界面微观结构的影响。试验结果表明，经电化学脱盐处理后，钢样-砂浆界面的微观形貌特征与组成发生了明显的变化。     

科学大洋钻探与深部生物圈

从深海钻探计划(DSDP)在20世纪70年代最早提出海洋沉积物中细菌活动性的证据到90年代大洋钻探计划(ODP)获得了令人信服的海底深部生物的存在证据，并成为即将启动的综合大洋钻探计划(IODP)的一个优先研究领域，深部生物圈成为科学大洋钻探近年来最为重大的发现之一，同时它也将有效地促进地球科学和生物学等其他学科的交叉。     

Fatigue Behavior of Plain Concrete Under Biaxial Compression: Experiments and Theoretical Model

The effects of different lateral confinement stress on the fatigue behavior of and cumulative damage to plain concrete are investigated experimentally. Eighty 100 mm x 100 mm x 100 mm specimens of ordinary strength concrete are tested under constant- or variable-amplitude fatigue loading and lateral confinement pressure in two orthogonal directions. A fatigue equation is developed by modifying the classical Aas-Jakobsen S-N equation for taking into account the effect of the confined stress on fatigue strength of plain concrete. The results of variable-amplitude fatigue tests indicate that the linear damage theory proposed by Palmgren and Miner is unreasonable in the biaxial stress state. A nonlinear cumulative damage model that could model the effects of the magnitude and sequence of variable-amplitude fatigue loading and lateral confinement pressure is proposed on the basis of the evolution laws of the residual strains in the longitudinal direction during fatigue tests. The residual fatigue life predic