南黄海物理-生物地球化学过程的时空异质性及内在关联和机制

研究多重物理过程控制下陆架边缘海生物地球化学过程的时空异质性及其生态响应,对于深入认识海洋生态系统具有重要的意义。基于相关历史观测资料和卫星遥感海表温度,本文综合分析了南黄海物理-生物地球化学过程的时空变化和空间异质性特征,探讨了该海域内部典型地理单元之间的内在关联和机制。结果显示,冷季沿岸流南向输送和暖季锋面上升流垂向输运的季节性交替是影响石岛外海与海州湾外侧海域生物地球化学和初级生产的重要物理过程。夏季苏北沿岸水的东北向扩展可形成浒苔离岸/跨区域输送的动力驱动。暖季水体层化显著影响着南黄海中部冷水团海域的生物地球化学过程,春至秋季冷水团海域底层水体中的营养盐逐渐累积,形成了营养盐的重要贮库;层化季节黄海冷水团边界锋区上升流系统的存在使得南黄海叶绿素a和初级生产力高值区位置同海表低温涌升流区总体相一致。冷季南黄海西部南下的冷水与中部北向入侵的暖水共同导致了“S”型锋面的形成;暖季黄海冷水团边界锋区的上升流系统是连接层化海域和近岸区的纽带,可实现对冷水团内部营养盐的提取,从而将冷水团内部和边界区的生物地球化学过程形成有机连接,并在成山角-石岛外海、海州湾外侧、苏北浅滩东部形成三个典型的物理-生物地球化学相互作用区。本研究细化和整合了南黄海区域海洋学研究,揭示了该海域物理-生物地球化学过程的空间异质性特征和不同地理单元之间的关联性及机制,获得了对南黄海水文-生物地球化学-生态过程的综合、系统认知。     

Particle trajectories of nonlinear gravity waves in deep water

The paper presents a numerical method for calculating the particle trajectories of nonlinear gravity waves in deep water. Particle trajectories, mass-transport velocity and Lagrangian wave period can be accurately determined by the proposed method. The high success rate of the proposed method is examined by comparing the present results with those of (a) Longuet-Higgins, M.S., 1986, 1987. Eulerian and Lagrangian aspects of surface waves. Journal of Fluid Mechanics 173, 683-707 and (b) Lagrangian moments and mass transport in Stokes waves. Journal of Fluid Mechanics 179, 547-555. It is shown that the dimensionless mass-transport velocity can exceed 10% for large waves, and the Lagrangian wave period is much larger than the Eulerian wave period for large waves.     

长山群岛海区春季水温垂直结构分析

利用海军大连舰艇学院2006年4月长山群岛海区的CTD调查资料,系统分析了该季节长山群岛海区的温度垂直结构,并探讨了其形成机理。分析指出:4月上、中旬是长山群岛海区季节性温跃层的生成期,群岛东侧和南侧边缘受黄海冷水团形成过程的影响,温跃层的出现概率和跃层强度都远远高于群岛内部;在生成时机上,群岛东侧和南侧边缘海域早于群岛内部水域。中间层和底层海水温度的垂直结构与海流有着很好的相关性,在海洋平流的作用下,海区会产生正跃层、逆跃层、冷中间层、暖中间层等复杂的温度垂直结构。上层海水温度结构主要受海面风场和气温的影响,较强的热辐射和充分的风力搅拌能够加速温跃层的生成。     

黄海冷水团海域微型异养鞭毛虫对异养细菌和蓝细菌摄食作用的初步研究

2006年10月在黄海冷水团海域的三个站点开展了微型异养鞭毛虫、异养细菌和蓝细菌的密度和生物量调查,进行了微型异养鞭毛虫的现场摄食实验,通过荧光标记细菌法和消化系数法获得该海区微型异养鞭毛虫对异养细菌和蓝细菌的摄食率,并估算了微型异养鞭毛虫对异养细菌和蓝细菌现存量及生产力的摄食压。结果显示,微型异养鞭毛虫、异养细菌和蓝细菌的密度分别为0.36×103~1.13×103,0.39×106~1.13×106和0.04×104~3.74×104cells/cm3,温跃层以上明显高于底层。微型异养鞭毛虫对异养细菌的摄食率为5.33~14.89个/(HF·h),对蓝细菌的摄食率为0.26×102~23.10×10-2cells/(HF·h),摄食率随深度而下降。微型异养鞭毛虫每天能消耗9.27%~33.08%的异养细菌现存量和8.12%~16.09%的蓝细菌现存量。同时,微型异养鞭毛虫对异养细菌和蓝细菌的日摄食量各占它们生产力的2.66%~13.10%和8.12%~16.09%。研究表明微型异养鞭毛虫的摄食可能不是秋季黄海冷水团海域浮游细菌及其生产力的主归宿。     

Spatial Variability of Mass Movements in the Satluj Valley,Himachal Pradesh during 1990～2006

Satluj Valley is known to have a history of landslides and related mass movement activities since the geological times. Geological and geomorphological settings combined with anthropogenic activities constitute a propensity towards slope failure. During the last two decades,the area witnessed substantial increase in athropogenic pressure,mainly due to the exploitation of hydropower potential,changing landuse pattern and population growth. In addition,a shift of the climatic patterns in the form of larger area falling under the influence of rains was observed. These natural as well as anthropogenic changes in the area have resulted in increased spatial coverage of landslide in the area. This paper documents these changes during 1990～2006.     

Mitigation of Ice-Induced Vibrations for Offshore Platforms Using Tuned Mass Damper

The problems of ice-induced vibration have been noticed and concerned since the 1960s, but it has not been well resolved. One reason is that the dynamic interaction between ice and structure is so complicated that practical ice force model has not been developed. The recent full-scale tests conducted on jacket platforms in the Bohai Sea presented that ice could cause intense vibrations which endanger the facilities on the deck and make discomfort for the crew. In this paper, the strategy of mitigation of ice-induced offshore structure vibration is discussed. Based on field observations and understanding of the interaction between ice and structure, the absorption mitigation method to suppress ice-induced vibration is presented. The numerical simulations were conducted for a simplified model of platform attached with a Tuned Mass Danlper （TMD） under ice force function and ice force time history. The simulation results show that TMD can fa- vorably reduce ice-induced vibrations, therefore, it can be considered to be an alternative approach to utilize. Finally, the application possibilities of utilizing TMDs on other miniature offshore structures in ice-covered areas of marginal oil fields are discussed.     

黄海冷水团演变过程及其与邻近水团关系的分析

黄海冷水团是出现在黄海的一种独特的水文现象.文中利用覆盖整个黄海的GDEM三维水温资料,结合近期一些大型调查所获得的有关观测研究结果,首先较系统地分析了黄海冷水团的形成和演变过程,并对冷水团3个冷中心的季节演变提出了一些与前不同的认识.同时,通过对黄海冷水团形成、发展和消亡与该海域温跃层演变关系的分析,进一步揭示了黄海冷水团演变的机理.然后,探讨了黄海冷水团演变过程中与青岛和仁川东南海域冷水团以及东海北部底层冷水的关系.分析表明,在黄海冷水团发展的鼎盛时期,青岛冷水团和仁川东南海域冷水团以及东海北部底层冷水皆包络其中.     

黄海冷水团夏季叶绿素垂向分布结构的影响机制

通过求解海冷水团叶绿素一维模式控制方程，首次对风搅拌混合、潮混合和光衰减强度的影响机制进行了解析研究。结果表明，湍流湿合过程和光的衰减强度对叶绿素夏季垂向分布结构具有重要影响。增强海面风搅拌合作用的结果，导致叶绿素表层分布趋于均匀；增强潮温合，导致叶绿素最大值增加，最大值的位置向海面抬升；减少光的衰减强度，导致叶绿素最大值增加，最大值的位置下沉。     

大别山北缘地质找矿中遥感方法的研究

本项工作着重探讨在植被覆盖、地质背景十分复杂的地区，利用遥感信息寻找金矿及其它多金属矿的方法。即从地层岩系、构造及构造交叉部位、蚀变带这三个方面，进行地质找矿专题信息特征提取方法的研究。最后，通过信息提取及影像综合特征，进行遥感地质制图，圈定找矿有希望的地段。     

Depositional environment and sedimentary of the basinal sediments in the Eibiswalder Bucht (Radl Formation and Lower Eibiswald Beds), Miocene Western Styrian Basin,Austria

The Eibiswald Bucht is a small subbasin of the Western Styrian Basin exposing sediments of Lower Miocene age. In the past the entire sequence exposed in the Eibiswalder Bucht has been interpreted as being of fluvial/lacustrine origin; here, results are presented of detailed sedimentological investigations that lead to a revision of this concept. The lowermost siliciclastic sedimentary unit of the Eibiswalder Bucht sequence is the Radl Formation. It is overlain by the Eibiswald Beds, which are subdivided into the Lower, Middle and Upper Eibiswald Beds. The Radl Formation and the Lower Eibiswald Beds are interpreted as a fan delta complex deposited along NNW-SSE striking faults. Based on the sedimentary facies this fan delta can be subdivided into a subaerial alluvial fan facies group, a proximal delta facies group and a distal delta/prodelta facies group. The Radl Formation comprises the alluvial fan and proximal delta facies groups, the Lower Eibiswald Beds the distal delta/prodelta facies group. The alluvial fan and the proximal delta consist of diverse deposits of gravelly flows. The distal delta/prodelta consists of wave-reworked, bioturbated, low density turbidites intercalated with minor gravelly mass flows. The prodelta can be regarded as as the basin facies of the small and shallow Eibiswalder Bucht, where marine conditions prevailed. The basin was probably in part connected with the Eastern Styrian Basin, the contemporary depositional environment of the Styrian Schlier (mainly turbiditic marine offshore sediments in the Eastern Styrian Basin). Analysis of the clast composition, in conjunction with the paleotransport direction of the coarse delta mass flows of the Radl Formation, shows that the source rocks were exclusively crystalline rocks ranging from greenschists to eclogites.