东太平洋地区DSDP573孔始新世末期的微玻璃陨石   总被引：5，自引：1，他引：5  

尹延鸿  万天丰  孙嘉诗 《海洋地质与第四纪地质》2001,21(4):37-42

通过研究 DSDP5 73孔的岩心样品 ,首次在该孔始新世与渐新世的界线地层含金属粘土层中发现了微玻璃陨石 ,且主要富集在其底部。一个样品 (5 g)中最多可达 12粒。这些微玻璃陨石主要呈球形、椭球形。用电子探针测试了其化学成分 ,Si O2 含量为 2 9.6 4%～ 5 8.93%,Al2 O3 为 3.42 %～ 2 0 .96 %,Fe O为 9.98%～ 2 9.5 5 %,Mg O为 4.32 %～ 16 .0 5 %,Ir为 0 .0 6 %～ 0 .81%。总体来说 ,微玻璃陨石的化学成分变化较大 ,可能与靶岩的成分变化较大有关。始新世末期北美微玻璃陨石场的展布方向约为 2 5 0°,这与太平洋板块运动方向改变所需要的矢量变化(2 45°)仅相差 5°,推测很可能是始新世末期陨星的撞击引起了太平洋板块在该时期的运动方向由 NNW突然变为NWW。  相似文献   

壳聚糖酶高产菌株的筛选和发酵条件的研究   总被引：6，自引：0，他引：6  

孙玉英  韩宝芹  刘万顺  张继泉  姚如永  彭睿 《中国海洋大学学报(自然科学版)》2007,37(2):266-272

从采集的土样中分离到1株产壳聚糖酶能力较强的菌株OU01,并对OU01进行了16S rDNA序列、形态及生理生化鉴定分析。16S rDNA序列分析表明该菌属于微杆菌属;该菌的形态特征与生理生化鉴定结果表明该菌与Microbacteriumsp.的相似性最高;因此将其初步鉴定为微杆菌属(Microbacterium)。同时对该菌的发酵条件进行了初步研究:该菌的最适培养基组成为(g/L):chitosan 10,(NH4)2SO420,MgSO4.7H2O 1.3,K2HPO4.3H2O 1.4,Glucose 1,Yeast extract 3,NaCl 5,起始pH=6.30。最适发酵温度为30℃,最佳发酵时间为96 h,在上述最优条件下,该菌株产酶达到118 U/mL。Microbacteri-umsp.OU01菌株为壳聚糖酶的研究和应用提供了新的来源。  相似文献   

富含半胱氨酸肠蛋白的研究进展     

陈燕  孙晨 《海洋科学》2020,44(6):148-151

富含半胱氨酸肠蛋白是一种含双锌指结构的小分子蛋白，其在锌离子转运、个体发育、免疫防御以及肿瘤发生等多种生理过程中发挥重要作用。作者主要对富含半胱氨酸肠蛋白的结构特点及其在发育和免疫方面的研究进展进行系统概述，并指出其相关作用机制尚待深入研究。  相似文献   

The European vision for oceans and seas—Social and political dimensions of the Green Paper on Maritime Policy for the EU     

Juan Luis Suárez de Vivero 《Marine Policy》2007

The EU Green Paper on Maritime Policy is the European response to the new generation of ocean strategies based on science, technology and innovation aimed at new objectives, such as the strengthening of security and access to new resources. The European character of the proposal is found in the presence of social, cultural and historical elements, what is called the “European vision”. The viability of a European vision of the oceans and the idea of maritime empire as an extension of the current concept of empire within the general context of emerging ocean strategies are the elements offered up for debate on this European Union initiative.  相似文献   

南海甲藻卡氏前沟藻的生长特性研究   总被引：1，自引：0，他引：1  

孙海燕  龙丽娟  吴军 《热带海洋学报》2006,25(6):68-71

从海南省三亚海域收集分离了甲藻卡氏前沟藻Amphidinium carterae藻种,并在实验室成功进行了人工培养,同时对其生长特性进行了研究。实验结果表明,接种初始的细胞密度对其生长率和最高细胞密度影响很小,实验室培养和大量养殖可以采取低密度接种;最适宜培养的环境条件盐度为34,温度为26℃,营养盐浓度为2K。在温度为18—30℃、盐度为26—42、K培养液浓度系列为1/16—2 K的条件下都可存活,最大指数期平均生长率为0.958分裂.d-1,获得的最大细胞密度为7.27×105cells.ml-1。实验结果与属温带的胶州湾同物种对比,表明该藻种生长特性与温带品系有明显差异。  相似文献   

1998年5-6月南海上混合层、温跃层 不同定义的比较   总被引：15，自引：0，他引：15  

贾旭晶  刘秦玉  孙即霖 《海洋湖沼通报》2001,97(1):1-7

本文根据混合层和温跃层的两种不同定义，对1998年南海南北部和西太平洋混合层和温跃层的定点观测资料进行了计算和分析，比较了不同定义确定的混层，温跃层的共同点和差异。在此基础上，得出南海和西太平洋的障碍层厚度。  相似文献   

黄河三角洲潮滩潮沟体系的分维特征   总被引：11，自引：2，他引：11  

孙效功  赵海虹  崔承琦 《海洋与湖沼》2001,32(1):74-80

利用分形分维方法对黄河三角洲潮滩和潮沟的地貌特征进行了定量研究。结果表明，潮滩和潮沟的分维值可以较好地反映潮滩潮沟的发育演化规律。随着时间的推移和潮沟潮滩的进一步发育，黄河三角洲潮沟的分维值呈逐渐增大的趋势，而潮滩的分维值则呈逐渐减小的趋势，两者在分维值的变化上存在着负相关关系。该研究为黄河三角洲潮滩发育时空谱系的建立和深入研究提出了一种新方法和新的定量指标。  相似文献   

随机海浪的列率谱分析研究     

孙孚  张书文 《海洋与湖沼》2001,32(5):547-550

首次将列率谱分析的方法引入到随机海浪的研究。根据不同环境条件下实验室资料，对列率谱与频率谱进行了比较。结果表明，列率频对频率谱高频部分有明显改善，特别对二倍频含能段的分辨具有明显的优越性。另外，列率谱具有计算速度快、简单易行、分辨率高等优点。  相似文献   

Impact of Two "El Niño" Events of Different Intensity on the Hypoxic Soft Bottom Macrobenthos off the Central Peruvian wast     

Juan  Tarazona  Wolf E.  Arntz Elba  Canahuire 《Marine Ecology》1996,17(1-3):425-446

Abstract. Monthly changes in the community structure of hypoxic soft-bottom macrobenthos have been studied at a station at 34 m depth in Ancón Bay (Peru) before and during two El Niño (EN) events. Of these events, 1982-83 is considered the strongest, and 1991–93 one of the most prolonged in the 20th century. On the oceanographic scale, EN 1982–83 ranges as "very strong", whereas EN 1991–93 ranges as "moderate".
The thermal anomalies at the station during EN 1982–83 (+ 7.8 °C) were almost twice those of EN 1991–93 (+ 4.1 °C). However, the community changes were not in all cases proportional to the extent of warming. Species numbers increased in a similar way (up to 24 species from near zero in each of the two events), but maximum faunal density was five times higher, and mean biomass was twice as high in 1982–83 compared with the event a decade later. Species diversity was slightly higher during EN 1982–83, whereas successional and trophic changes occurred on a broader scale during EN 1991–93. On the whole, the impact of the long-lasting event on the small soft-bottom macrofauna was not much weaker than that of the exceptionally strong event.
The authors discuss the mechanisms which may be responsible for the differences and similarities encountered in the benthic community dynamics during these two events. Both in the unusually strong and the unusually long EN, the community revealed a pattern of early biological response several months ahead of the onset of local warming which marks the official begin of EN. The question is addressed to what extent the increase of certain parameters in the benthic community could be used for predictive purposes.  相似文献   

PROPAGATION AND TRANSFORMATION OF NON-LINEAR WAVES ON UNIFORMLY SLOPING BEACHES Ⅰ. A SOLUTION FOR NON-LINEAR PROGRESSING WAVES     

孙孚 《海洋学报(英文版)》1987,6(1):8-19

Two-dimensional non-linear hydrodynamical equations are solved by using perturbation method and treating slopping beaches as bottom boundary conditions so that a kind of solution for nonlinear progressing waves is obtained. The first order of approximation is the same potential function as used by Biesel, and the second order is calculated numerically. Based on the solution, wave characteristics before breaking, especially the wave set-down, are discussed. It turns out that for the whole course of waves propagating from deep to shallow waters the theory proposed in this paper has a wider valid range of application than others.  相似文献