洪泽湖风生流数值模拟   总被引：2，自引：0，他引：2  

姜加虎  黄群 《海洋湖沼通报》1996,(3):7-12

湖流是湖泊中污染物质扩散，悬浮物沉降及输移等的主要水动力学要素，造成湖水运动的成因机制很复杂，其中风生流是重要形式，本文通过构造一个二维闭边界数值模拟，对不同风情下的洪泽湖湖流流态进行模拟研究，探讨其入流较小，沿岩各闸关闭的枯季情况下的风生流特征。  相似文献   

Analysis of Mixing of Pollutants in Water Waves and Currents     

袁丽蓉  沈永明唐军 《中国海洋工程》2007,21(1):115-124

A vertical two-dimensional turbulence numerical model for the interaction of waves and currents is developed in the paper based on the nonlinear two-equation k-ε model with the VOF method.The one-dimensional equivalent advection velocity and equivalent mixing coefficient are defined and the solving process is introduced:The pollutant concentration field,generated by an instant source in waves and currents,is calculated with the model,and then the equivalent advection velocity and equivalent mixing coefficient are obtained by calculating the time derivative of the mean and variance of pollutant concentration probability distribution.The effects of wave period and wave height on the equivalent mixing coefficient for waves and wave-currents are also investigated.  相似文献   

The Mathematical and Parameterized Expressions for Wave Induced Excess Flow of Momentum     

朱首贤丁平兴  张文静 《中国海洋工程》2007,21(1):137-146

Wave induced excess flow of momentum(WIEFM)is the averaged flow of momentum over a wave period due to wave presence,which may also be called 3-D radiation stress.In this paper,the 3-D current equations with WIEFM are derived from the averaged Navier-Stokes equations over a wave period,in which the velocity is separated into the large-scale background velocity,the wave particle velocity and the turbulent fluctuation velocity.A concept of wave fluctuating layer(WFL)is put forward,which is the vertical column from the wave trough to wave ridge.The mathematical expressions of WIEFM in WFL and below WFL are given separately.The parameterized expressions of WIEFM are set up according to the linear wave theory.The integration of WIEFM in the vertical direction equals the traditional radiation stress(namely 2-D radiation stress)given by Longuet-Higgins and Stewart.  相似文献   

分层流体中内孤立波在潜浮式竖直薄板上透射和反射   总被引：2，自引：0，他引：2  

魏岗  尤云祥  缪国平  苏晓冰 《海洋工程》2007,25(1):1-8

采用边缘层理论研究了两层流体系统中内孤立波在潜浮式竖直薄板上的透射和反射问题,提出了非线性演化方程的“初值”条件,分析了内孤立波与薄板非线性相互作用的效应。研究表明:流体层的密度比以及薄板伸入上下层的深度对于反射和透射波结构具有显著的影响,薄板伸入下层越深、密度差越小,则薄板阻碍孤立波透射的效率越高;透射波通常演化为单峰孤立波和迅速衰减的尾波,反射波演化为缓慢衰减的尾波列;对于具有小密度差的跃层结构,内孤立波在潜浮式竖直薄板上的透射及其演化近乎是无障碍的。  相似文献   

地磁场强度变化对暴露年代测定的影响及校正     

邵庆丰  陈仕涛 《海洋地质与第四纪地质》2007,27(1):87-93

在103-105a的尺度上,地磁场强度变化是影响陆地宇生核素生成速率的主要因素,其影响程度取决于样品的地理位置和暴露时间。根据已有的磁场古强度数据,模拟200 ka以来海拔2 km、25°N和40°N的地表10Be生成速率的变化,进而分析地表宇生核素生成速率变化对岩石暴露年代测定的影响及其模式年龄的校正。校正磁场强度变化后,海拔2 km、25°N上,50-200 ka的模式年龄可被压缩14%~19%,大于1σ的误差,相同海拔40°N上的模式年龄可减小约8%。对中低纬两组模式年龄的校正充分证明,磁场强度引起的陆地宇生核素生成速率变化是暴露年代测定中主要误差源之一,尤其在低纬高海拔地区这一影响更不容忽视。  相似文献   

海洋湍流观测技术   总被引：3，自引：0，他引：3  

康建军  邬海强  杨庆轩  付红丽 《海洋技术学报》2007,26(3):19-23

湍流在海洋能量和水体的交换演化中起着非常重要的作用。海洋湍流研究的发展和海洋湍流观测仪器的研发密切相关。世界上湍流观测仪器的研发起步于上世纪50年代,但是我国在湍流观测设备方面到目前为止仅仅处于起步和引进国外设备阶段。针对我国的情况,文中对海洋湍流观测的平台、探头测量原理及其数据修正、资料后处理等关键技术做一个总结性的介绍,为我国使用引进的海洋湍流设备和自主开发海洋湍流测量设备提供参考。  相似文献   

Ensuring confidence in radionuclide-based sediment chronologies and bioturbation rates   总被引：1，自引：0，他引：1  

John Crusius  Timothy C. Kenna   《Estuarine, Coastal and Shelf Science》2007,71(3-4):537-544

Sedimentary records of naturally occurring and fallout-derived radionuclides are widely used as tools for estimating both the ages of recent sediments and rates of sedimentation and bioturbation. Developing these records to the point of data interpretation requires careful sample collection, processing, analysis and data modeling. In this work, we document a number of potential pitfalls that can impact sediment core records and their interpretation. This paper is not intended as an exhaustive treatment of these potential problems. Rather, the emphasis is on potential problems that are not well documented in the literature, as follows: (1) the mere sampling of sediment cores at a resolution that is too coarse can result in an apparent diffusive mixing of the sedimentary record at rates comparable to diffusive bioturbation rates observed in many locations; (2) ²¹⁰Pb profiles in slowly accumulating sediments can easily be misinterpreted to be driven by sedimentation, when in fact bioturbation is the dominant control. Multiple isotopes of different half lives and/or origin may help to distinguish between these two possible interpretations; (3) apparent mixing can occur due simply to numerical artifacts inherent in the finite difference approximations of the advection diffusion equation used to model sedimentation and bioturbation. Model users need to be aware of this potential problem. Solutions to each of these potential pitfalls are offered to ensure the best possible sediment age estimates and/or sedimentation and bioturbation rates can be obtained.  相似文献   

0010号台风"碧利斯"对厦门港湾表层海水中溶解无机砷含量的影响     

李俊  郑佩如  杨逸萍  胡明辉 《台湾海峡》2002,21(4):404-410

本文研究了0010号台风“碧利斯”影响期间及其随后的恢复期中,厦门港湾中九龙江口和西港海域站表层海水总溶解砷（TDIAs)、As^3 含量和As^3 /As^5 值的变化特征。结果表明,观测期间两站TDIAs和As^5 含量均比非台风时期呈数倍增加,经10d后仍未恢复到非台风时的水平。As^3 含量也有较大幅度的增加,但波动较大。文中还对观测期间影响溶解无机砷含量的因素进行了初步的探讨。  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   

Research on the spectral analysis and test method of period signals in monthly mean sea level     

Ma Jirui  Tian Suzhen  Zheng Wenzhen  Chai Xinmin 《海洋学报(英文版)》1995,14(2):181-190

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