太平洋凸缘微玻璃陨石的研究     

彭汉昌  刘正坤  庄世杰 《海洋与湖沼》1992,23(6):642-646

于1985年,一颗独特的凸缘微玻璃陨石被发现于采自北太平洋(9°33′N,167°00′W;水深4928m)深海沉积物中。使用各种分析方法对它的显微特征、微结构和化学成分进行了研究。结果表明,太平洋凸缘微玻璃陨石的形态和结构与达尔文的凸缘澳大利亚石(或玻璃陨石)和查普曼的人造凸缘玻璃陨石相似,从而揭示了玻璃陨石和微玻璃陨石的凸缘结构是由空气动力消融作用的产物。这一研究具有重要的理论和实际意义。  相似文献   

Semi-Probabilistic Evaluation of System Redundancy for Existing Offshore Structures     

Zhang Shengkun Chen Kaisheng Mu Yang Professor 《中国海洋工程》1995,(1)

In this paper, a new definition of structure system redundancy is proposed in view of the various measures for structure redundancy. By introducing the terms of structure system failure at the mechanism level and equivalent reliability index, the safety for existing offshore platforms can be evaluated by the semi-probabilistic method presented in this paper. Some numerical examples are given and satisfactory results have been obtained.  相似文献   

牙鲆种群动态及其资源管理     

朱鑫华 《海洋与湖沼》1992,23(3):270-279

本文根据1980—1986年间鱼类生物学参数测定,结合体长分布资料的模拟分析,研究黄、渤海区牙鲆种群年龄结构、死亡动态以及在不同年龄和死亡率条件下世代资源生物量变化的规律。模型分析结果表明,当F=1.0和t_c=6.0a时,单位补充量最大群体产量为1492g。由此认为,现阶段牙鲆资源利用的最佳策略是通过增殖放流,增加资源补充;同时应适当控制捕捞压力,减少渔具对幼鱼资源的破坏并增设繁殖保护区,以追求最大持续产量。  相似文献   

Measurements of higher harmonic wave forces on a vertical truncated circular cylinder     

S.Y. Boo   《Ocean Engineering》2006,33(2):219-233

Wave forces on a vertical truncated circular cylinder in Stokes waves with the wave slopes ranging from 0.06 to 0.24, are measured in a wave tank. The higher harmonic wave forces are compared with the available values from theories of the FNV (Faltisen–Newman–Vinje) model and Varyani solution. The first harmonic horizontal forces measured are much larger than the theoretical values from the FNV model, while the first harmonic vertical forces are well predicted by the Varyani theory. It was also found that the FNV model significantly overpredicts the second harmonic horizontal forces in high frequency waves, but under predicts the third harmonic forces. The differences between the actual measurement and the theory, in the second and third harmonic horizontal forces, become smaller at low wave frequencies as the wave slope increases. In addition, the transverse instabilities in the incoming waves with high wave slope were observed, which is due to the nonlinear modulation. Measurements were, thus, carried out before the instability occurred.  相似文献   

Ekman螺线的动力学结构     

纪文君  王卫强 《台湾海峡》2002,21(3):340-343

介绍了Ekman螺线的动力学结构 ,分析研究了风应力及海水内部的动量传递形式 .结果表明 :动量传递方向与海流方向成 45°左偏 .这对于研究海洋内部的动力结构是有意义的 .  相似文献   

舟山沿海单齿螺（Monodonta labio）种群的年龄结构,生物量与生长特征     

王一农  王旭华 《海洋湖沼通报》1995,(1):54-60

本文报导了采自舟山沿海单齿螺种群的年龄结构、生物量与生长。自然种群的单齿螺年龄组成以１＾＋和２＾＋龄占优势，壳高、壳宽、壳口高、厣径、体重等生长参数的回归关系良好，单齿螺的生长完全可以用壳高来表示。单齿螺以第一、二年生长最快。采捕季节可定在四、五月间，采捕规格应在壳高１６ｍｍ以上。  相似文献   

Vertical Distribution of Meiobenthos in Bathyal Sediments of the Eastern Mediterranean Sea: Relationship with Labile Organic Matter and Bacterial Biomasses     

Roberto  Danovaro  Mauro  Fabiano  Giancarlo Albertelli  Norberto Della  Croce 《Marine Ecology》1995,16(2):103-116

Abstract. Quantitative information on the vertical distribution of meiofaunal abundances and biomass were obtained from samples collected at 3 bathyal stations in the Eastern Mediterranean Sea located at the same depth but characterized by different food supply. Vertical distribution patterns of nieiofauna were investigated in relation to the biochemical composition of the sediment organic matter (proteins, carbohydrates, and lipids) and compared to benthic bacterial standing stocks. No significant relationship between bacteria and meiofauna was found, whereas a significant relationship between protein and lipid concentrations and total meiofauna density was observed. These data suggest that labile organic matter. considered as material readily aVdihbk to benthic consumers, may be an important factor regulating meiofaunal abundance and vertical distribution in deep-sea sediments.  相似文献   

Dynamic Analysis of a Single-Column Platform (II)     

Lian Gan  Ni Kan  Hu Kai Guo Dawei . Professor  Senior Engineer  Marine Design & Research Institute of China  Shanghai . Senior Engineer  Marine Design & REsearch Institute of China  Shanghai . Engineer  Marine Design & Research Institute of China  Shanghai 《中国海洋工程》1992,(4)

This paper describes the study of a single-column structure used as well-head platform. In order to check the reliability of computation theory and programme, model tests have been carried out. The paper introduces the conclusion of tests and the dynamic properties of single-column platform are obtained.  相似文献   

A Note on Soil Structure Resistance of Natural Marine Deposits   总被引：1，自引：1，他引：1  

洪振舜刘松玉  刘志方 《中国海洋工程》2004,18(2):321-326

It has been well documented that natural normally-consolidated marine soils are generally subjected to the effects of soil structure. The interpretation of the resistance of soil structure is an important issue in the theory study and engineering practice of ocean engineering and geotechnical engineering. It is traditionally considered that the resistance of soil structure gradually disappears with increasing stress level when the applied stress is beyond the consolidation yield stress. In this study, however, it is found that this traditional interpretation of the resistance of soil structure can not explain the strength behavior of natural marine deposits with a normally-consolidated stress history A new interpretation of the resistance of soil structure is proposed based on the strength behavior. In the preyield state, the undrained strength of natural marine deposits is composed of two components: one developed by the applied stress and the other developed by the resistance of soil structure. When the applied stress is beyond the consolidation yield stress, the strength behavior is independent of the resistance of soil structure.  相似文献   

贻贝(Mytilus edulis Linnaeus)唇瓣的扫描电镜观察     

范瑞青  姜明  任素连  高澜 《海洋湖沼通报》2002,(4):52-55

本文运用扫描电子显微镜技术研究了贻贝唇瓣的形态结，结果表明，贻贝唇瓣外部形态呈羽毛状，分为光滑面和皱褶面；褶皱面表面被覆浓密纤毛，分有沟嵴和无嵴两部分，界限明显，光滑面纤毛较少，呈簇状，分布不均，在褶皱面中央分界处和光滑面的一侧，有大量球状突起，为杯状细胞所在，纤毛和粘液在食物分拣和运输中起重要作用。  相似文献