近海层大气湍流通量系数研究

根据１９９４年９月１８～３０日南沙群岛海域渚碧礁的近海面大气湍流观测实验资料，分别计算了该海域光滑海面和粗糙海面上的空气动力粗糙度（ｚ０ ）、中性曳力系数（ Ｃ Ｄ Ｎ）。利用 Ｂｕｔｓａｅｒｔ 的假定，推导了求取标量粗糙度（ｚ Ｔ、ｚ Ｑ）、整体输送系数（感热交换系数 Ｃ Ｈ Ｎ、水汽交换系数 Ｃ Ｅ Ｎ ）的一组公式。在此基础上，分别计算和分析了该海域光滑海面和粗糙海面上空气动力粗糙度（ｚ０ ）、标量粗糙度（ｚ Ｔ、ｚ Ｑ ）、中性曳力系数（ Ｃ Ｄ Ｎ）、整体输送系数（感热交换系数 Ｃ Ｈ Ｎ、水汽交换系数 Ｃ Ｅ Ｎ）及其关于水平风速分量的分布，并得到了一些有益的结论。

近海层大气湍流对舰船激光通信的影响

近海层大气湍流对舰船激光通信有重要的影响。本文基于Kolmogorov和Rytov大气湍流理论,推导适用于描述强、弱湍流条件下信噪比及误码率的理论模型,结合舰船通信的物理条件进行数值仿真,同时分析在相应湍流强度下大气湍流对不同波长激光通信性能指标的影响,并提出提高通信质量的措施。

近海浅层气甲烷浓度原位在线监测方法与仪器研究

近海浅层气实时原位在线监测对海洋建设工程的安全施工至关重要。提出了一种基于薄膜界面检测的近海浅层气甲烷浓度实时原位在线监测方法并进行了仪器研究。设计的近海浅层气检测探头实现了浅层气与沉积物的分离、甲烷气体浓度的检测、测量数据传输至监测数据汇集节点。仪器的信号汇集节点将接收的测量数据无线发射到上位机的接收电路,上位机实现测量数据的处理、记录和存储。搭建的模拟沉积物试验装置利用一系列不同标准浓度的甲烷气体对所设计的气体探头进行了验证,测量结果的相对误差均在-0.1%以内,实验结果表明设计的仪器具有优良的性能。最后选取了实际测量点完成了现场实时测量,实现了气体检测探头一次贯入海底,以及区域化、原位和在线浅层气中甲烷浓度的有效监测。

基于薄膜界面探测的近海浅层气中甲烷浓度检测

基于薄膜界面探测的近海浅层气中甲烷浓度检测是利用特定的高分子气液分离渗透膜将浅层气从海水中分离出来,内部的红外甲烷气敏传感器感知甲烷浓度输出相应的模拟量值。数据采集与通讯节点将输出的模拟量拟合处理为具体的气体浓度值,并无线发送给上位机。实验结果表明,具有对近海浅层气中甲烷实现原位在线检测的能力,可操作性强。

浙江近海浅层天然气的分布特征及其对工程建筑的影响

本文根据钻探资料与浅地层剖面仪探测资料分析,发现整个浙江近海普遍贮藏着浅层天然气。文章指出浅层天然气的存在及其分布的差异性,将对浙江沿岸港口的开发及工程设施等方面带来不同程度的影响。

近海浅层折射波时距曲线的一种解释方法

本文所讨论的折射波时距曲线的解释方法，是建立在利用时距曲线的特征点——直达波与折射波两时距曲线或两折射波时距曲线的交点的基础上的。该点的时间值用to表示(crossover time)，故此解释方法可简称为to法。它比通常用的to法(又称t1法，method of intercept time)的最大优点是不需要确定激发点的位置，因此给实际工作带来了方便。

Late Cenozoic Tectonic Deformation in the Dongsha Islands and Adjacent Sea Area

Dongsha Island and the adjacent sea area locate at the northern continental margin of the South China Sea (SCS), and is connected to the east by the Manila Trench. Analyses of seismic stratigraphy and gravity, magnetic and drilling wells data led to the discovery of three post fault sequences (V, VI, VII). Extensive tectonic uplift, magma activity and erosion occurred in Dongsha Island and the adjacent area, where most of the faults in the northeastern SCS were still active during Pliocene and Quaternary. Two groups of faults trending NEE and NW were developed during Late Cenozoic. We conclude that three important tectonic movements, especially Dongsha movement (4.4-5.2 Ma) and Liuhua movement (1.4-1.89 Ma), controlled the structural framework in the Dongsha rise; whose deformation in the east is stronger than that in the west and whose stress field variation suggests that the tectonic uplift in the study area contributed to magmato tectonic events correlated to the main collision phases between the East China and Taiwan 5-3 and 3-0 Ma ago.

Diatom distribution in surface sediments from Chinese inshore waters and the relationship to modern environmental variables

Diatoms are widely used to study past and present changes in the marine environment. Unimodal models are appropriate for exploring the relationship between environmental properties in Chinese inshore waters and fossil diatom species derived from modem surface sediments. The best-fit relationships between two multivariate datasets （diatom species and environmental variables） were identified using canonical correspondence analysis （CCA）, which is a constrained ordination technique. The absolute abundance of diatoms in the Chinese inshore waters ranged from 500 to 48 000 valves/g, and the average absolute abundance of all the 29 sites was l l 300 valves/g. 153 species and varieties of diatoms belonging to 42 genera in all were identified in the Chinese inshore waters. There were 28 dominant diatom species in all. According to the absolute abundance of the dominant species and the spatial distribution of the currents from the Chinese inshore waters, 12 diatom assemblages were distinguished from north to south, which reflected the different oceanographic conditions at the regional scale. Of the eight environmental variables considered, the most important environmental variable is winter sea surface salinity （WSS）, which was also the only environmental variable with statistical significance. Therefore, it may be used to establish a transfer functions for the Chinese inshore waters in future paleoclimate studies.

Quantitative Seismic Risk Evaluation on Blind Faults in Offshore Areas of Tianjin,China

Based on faults surveying and research data in the Tianjin offshore areas,through studying tectonic structure,Quaternary activity,deep structure,stress and strain fields and seismicity in the Tianjin offshore areas,the activity and tectonic features of the faults are determined synthetically.Using seismo-geological data,and the historical and modern seismicity data,the frequency-magnitude relationship model normalized by 500a is established and based on the relationship between the upper limit of maximum magnitude M u and a t/b,the maximum magnitudes of the sea section of the Haihe river fault and the Haiyi fault are calculated.Then Poisson probability model is adopted and the quantitative parameters,such as the maximum magnitude,occurrence probability,recurrence cycle of the faults in the south Tianjin offshore areas in the coming 50～200a,are calculated.

近岸海洋气象平台涡动相关数据处理与质量控制

涡动相关方法在海洋—大气界面通量过程的观测研究中得到广泛应用。通量观测的数据质量很大程度上取决于环境条件和订正方法的正确应用,因此需要对数据进行处理与质量控制。基于博贺海洋气象平台上方2层涡动相关系统约7个月的湍流观测数据,分析了目前未能在数据采集平台上实时运行的几种订正方法对通量结果的影响。分析表明:在通量值较小时,去野点可使通量值发生很大改变;大部分情况下去野点对通量(包括摩擦速度、潜热、感热与CO2)造成的改变小于1%。由于该观测点的大气边界层下垫面为波浪场,平面拟合的效果要明显优于二次旋转。频率损失订正结果显示,订正系数随风速的变化存在较大波动,此项订正平均可使各种湍流通量增强5%～8%,夜晚的订正幅度稍大于白天的情况。湍流通量的频率累积检测显示,对于大气层结稳定性发生转换的时段,30 m in的累积时间长度不足以包括低频事件对通量的贡献。最后,总体湍流特征检验与平稳性检验显示,50%左右的数据可用于基本研究。2层通量结果的比较也显示,博贺站的通量数据质量可以得到保证。

The important turning points during evolution of Cenozoic basin offshore the Bohai Sea:Evidence and regional dynamics analysis

The Cenozoic basin offshore the Bohai Sea underwent a multicycle-rifting during its evolutionary process, which resulted in the multiple unconformities in the strata. The tectonic activities shown by these unconformities have different manifestations and influences on the basin evolution. The authors systematically analyze the tectonic evolution characteristics of the sags off-shore the Bohai Sea with a large set of hydrocarbon exploration data. The analysis reveals that two phases of tectonic activities during the late depositional stage of the third member of Shahejie Formation (about 38 Ma) and the late depositional stage of Dongying Formation (about 24 Ma) reflect the significant changes in the basin's features and structural framework before and after these tectonic activities. As a result, the two phases of tectonic activities are recognized as important turning points (i.e., tectonic transitions) of Cenozoic basin evolution. The regional dynamic backgrounds of the two phases of tectonic transitions are also discussed. It is suggested that the early tectonic transition occurred at about 38 Ma under such regional dynamic back- ground that a huge kinematics adjustment happened between Eurasian Plate and its neighboring plates, i.e., Pacific Plate and Indian Plate. Meanwhile, the Tan-Lu Fault's slip reversed from left lateral to right lateral. The late tectonic transition occurred in late Paleogene (about 24 Ma) and reflected the Himalayan orogeny's influence on the Chinese continent and even the Asian continent; at the same time, the stress field produced by the escape tectonics was related to the Himalayan orogeny, superposed on the pre-existing stress field, and then enhanced the right lateral slip activity of the Tan-Lu Fault.