某船坞南翼墙基岩水下控制爆破技术     

徐清明  穆旭 《海岸工程》1997,16(3):47-54

本文介绍的基岩水下爆破属临近重要建筑物的水下控制爆破。当岩石裂隙发育，且岩面有较厚的石碴覆盖层，其技术难度大，采取的诸如搭钢平台钻孔。塑料套管护孔，以及孔间、排间塑料导爆管雷管接力式微差起爆网路等措施，都是成功之经验，值得今后类似工程推广应用。  相似文献   

银川盆地中更新世以来的孢粉记录及古气候研究   总被引：8，自引：1，他引：8  

杨振京  刘志明  张俊牌  童国榜  阳小兰 《海洋地质与第四纪地质》2001,21(3):43-49

银川盆地中更新世以来的孢粉记录及据此所重建的古气候参数，揭示了该区中更新世以来的古气候演变特征，其演变经过了温湿→凉湿→温和→冷湿→温干→凉较湿→冷湿→温干→凉润→温较干→温干的变化，并与新疆地区，黄土高原以及深海δ^18O曲线进行了对比，结果表明，各地的古环境变化大致同步，该区由于位置靠西，邻近沙漠，最近地质历史时期的区域性干旱特色明显。  相似文献   

黄海海域陆相中生界油气远景   总被引：8，自引：1，他引：8  

李刚  陈建文  肖国林  温珍河  戴春山  龚建明  闫桂京 《海洋地质前沿》2003,19(8):7-11

黄海海域油气勘探已40余载，尚未实现油气突破，其找油前景引起石油地质学家的极大关注。根据前人的认识和最新研究成果，结合邻区油气地化资料，探讨了黄海海域中生界地层生、储、盖特征，特别是白垩系，它分布广，厚度大，烃源岩达到较好生油岩标准，并且生、储、盖组合理想，中生界是该区下部油气勘探首选目标。  相似文献   

Effects of cold eddy on phytoplankton production and assemblages in Luzon strait bordering the South China Sea   总被引：6，自引：0，他引：6  

Yuh-Ling Lee Chen  Houng-Yung Chen  I. -I. Lin  Ming-An Lee  Jeng Chang 《Journal of Oceanography》2007,63(4):671-683

The biochemical effects of a cold-core eddy that was shed from the Kuroshio Current at the Luzon Strait bordering the South China Sea (SCS) were studied in late spring, a relatively unproductive season in the SCS. The extent of the eddy was determined by time-series images of SeaWiFS ocean color, AVHRR sea surface temperature, and TOPEX/Jason-1 sea surface height anomaly. Nutrient budgets, nitrate-based new production, primary production, and phytoplankton assemblages were compared between the eddy and its surrounding Kuroshio and SCS waters. The enhanced productivity in the eddy was comparable to wintertime productivity in the SCS basin, which is supported by upwelled subsurface nitrate under the prevailing Northeastern Monsoon. There were more Synechococcus, pico-eucaryotes, and diatoms, but less Trichodesmium in the surface water inside the eddy than outside. Prochlorococcus and Richelia intracellularis showed no spatial differences. Water column-integrated primary production (IPP) inside the eddy was 2–3 times that outside the eddy in the SCS (1.09 vs. 0.59 g C m⁻²d⁻¹), as was nitrate-based new production (INP) (0.67 vs. 0.25 g C m⁻²d⁻¹). INP in the eddy was 6 times that in the Kuroshio (0.12 g C m⁻²d⁻¹). IPP and INP in the eddy were higher than the maximum production values ever measured in the SCS basin. Surface chlorophyll a concentration (0.40 mg m⁻³) in the eddy equaled the maximum concentration registered for the SCS basin and was higher than the wintertime average (0.29 ± 0.04 mg m⁻³). INP was 3.5 times as great and IPP was doubled in the eddy compared to the wintertime SCS basin. As cold core eddies form intermittently all year round as the Kuroshio invades the SCS, their effects on phytoplankton productivity and assemblages are likely to have important influences on the biogeochemical cycle of the region.  相似文献   

琉球群岛东部海区表层沉积物中浮游有孔虫分布及指示意义     

吴永华  程振波  石学法  李小艳  石丰登  鞠小华 《海洋地质与第四纪地质》2007,27(6):1-7

对琉球群岛东部海区123个表层沉积物样品中浮游有孔虫因子分析结果表明,浮游有孔虫组合在溶跃面以上表现为Globigerinoides ruber-Globigerinata glutinata组合,溶跃面以下为Globorotalia inflata-Neoglobo-quadrina pachyderma (dex.)组合,局部受黑潮影响区域黑潮标志种Pulleniatina obliquiloculata含量相对丰富,为Neogloboquadrina dutertrei-P.obliquiloculata组合;表层沉积物中浮游有孔虫的丰度及组合分布特征对于碳酸盐溶跃面深度及碳酸盐补偿深度有一定的指示意义。另外,碳酸盐保存特征研究表明,该区域现代碳酸盐溶跃面深度约为3100 m,碳酸盐补偿深度约为4300 m。  相似文献   

Effects of pulsed nutrient inputs on phytoplankton assemblage structure and blooms in an enclosed coastal area   总被引：6，自引：0，他引：6  

Sofie Spatharis  George Tsirtsis  Daniel B. Danielidis  Thang Do Chi  David Mouillot   《Estuarine, Coastal and Shelf Science》2007,73(3-4):807-815

The response of phytoplankton assemblage structure to terrestrial nutrient inputs was examined for the Gulf of Kalloni in the Northern Aegean Sea, a productive semi-enclosed coastal marine ecosystem. The study was focused on a typical annual cycle, and emphasis was placed on the comparative analysis between blooms developing after significant nutrient inputs from the watershed, and naturally occurring blooms. Baseline information was collected on a monthly basis from a network of stations located in the oligotrophic open sea and the interior and more productive part of the embayment. Intensive sampling was also carried out along a gradient in the vicinity of a river which was the most important source of freshwater and nutrient input for the Gulf. Phytoplankton assemblage structure was analyzed from 188 samples using diversity indices (Shannon and Average Taxonomic Distinctness), multivariate plotting methods (NMDS), multivariate statistics (PERMANOVA), and canonical correspondence analysis (CCA). Three characteristic assemblages were recognized: (1) an autumn assemblage developed under nutrient depleted conditions, having low diversity due to the dominance of two small diatoms, (2) a winter bloom of the potentially toxic species Pseudo-nitzschia calliantha occurring immediately after a nutrient peak and characterized by very low diversity, and (3) a naturally occurring early summer bloom of centric diatoms with relatively high diversity. The results of the study support the view that moderate nutrient inputs may have a beneficial effect on the functioning of coastal ecosystems, stimulating the taxonomic diversity through the growth of different taxonomic groups and taxa. On the other hand, a sudden pulse of high nutrient concentrations may greatly affect the natural succession of organisms, have a negative effect on the diversity through the dominance of a single species, and can increase the possibility of a harmful algal bloom development.  相似文献   

泉州湾海域表层沉积物矿物碎屑分布特征及其环境意义   总被引：4，自引：0，他引：4  

谷东起  边淑华  胡泽建  张绪良 《海岸工程》2003,22(2):22-30

对泉州湾13个表层沉积物样品进行了矿物碎屑定量分析．通过矿物分析，发现泉州湾不同站位的轻、重矿物组分、含量和表征存在差异．根据矿物的分布和组合特征．将耒州湾划分为4个组合区，不同组合区所处沉积环境是不同的．分析表明，研完区表层沉积物的碎屑矿物具有明显的亲陆性，物质来源主要为河流输砂和沿湾海岸侵蚀来砂，且其分布受物源、水动力条件和矿物物理性质等因素所控制。  相似文献   

厌氧沉积中有孔虫组合特征     

程广芬 《中国海洋大学学报(自然科学版)》1988,(1)

厌氧沉积的有孔虫组合中,底栖有孔虫主要由Bolivina诸种和Buliminella tenuata组成,同时含有少量厌氧标志种Suggrunda eckisi;浮游有孔虫中以Globigerrina bulloides和G.quingueloba为数较多。底栖有孔虫与浮游有孔虫数量相比,浮游有孔虫数量很少。  相似文献   

华南沿海地区全新世海平面变化特征     

李建生 《海洋科学》1994,18(3):68-71

１海平面变化特征１．１全新世中期海侵根据地层中所含硅藻属种雷州半岛海康南田乡一１５ｍ钻孔岩芯，含有丰富的硅藻，主要属种是①：具槽直链藻（Ｍｅｌｏｓｉｒａ　ｓｕｌｃａｔａ（Ｅｈｒ）Ｋｕｔｚ）、范氏回箱藻（Ｐｙｘｉｃｌｉｃｕｌａ　ｗｅｙｐｒｅｃｈｔｉｉＧｒｕｎ）、条纹小环藻（Ｃｙｃｌｏｔｅｌｌａｓｔｒｉａｔａ（Ｋｕｔｚ）Ｇｒｕｎ）、流水双菱藻（ＳｕｒｉｒｅｌｌａｆｌｕｍｉｎｅｎｓｉｓＧｒｕｎ）。上述硅藻主要是海相生活属种，今日南田乡已距离海岸线５ｋｍ。徐闻海安西侧一１８．５ｍ钻孔岩芯中的硅藻除上述属…  相似文献   

渤海中、南部表层沉积硅藻的定量分析   总被引：4，自引：0，他引：4  

程广芬  曹玉强 《中国海洋大学学报(自然科学版)》1991,(4)

对取自渤海中、南部海底表层的44个沉积物样品进行了硅藻分析。样品中共含硅藻20属41种,主要是潮间带、沿岸性底栖或浮游种类,其中尤以具槽直链藻Melosira sulc-ata和小环藻Cyclotella最多见。对本区的表层沉积硅藻用多元统计方法进行分区,共划分出三区、两亚区,井与其他海区进行了比较。  相似文献