不同刚度植物杆群对规则波传播及紊动特性影响研究

以不同刚度硅胶圆杆群为概化植物模型,测定其抗弯弹性模量,通过波浪水槽实验,研究规则波在不同刚度植物杆群内的流速分布、紊动特征及不同刚度杆群的消浪效果。实验结果表明,当波浪通过柔性杆群时,受其摆动的影响,流速周期变化从单峰型逐渐转变成双峰型,杆群刚度越小形成的二次波峰越明显;不同刚度杆群内水体紊动强度变化显示,杆群刚度越大,造成杆群内水体的紊动强度越大;随着杆群抗弯弹性模量的增大,其消浪系数也增大,消浪系数的增长与材料的抗弯弹性模量值非线性关系,而是在某一弹性模量范围内,对消浪系数的影响较为敏感。     

黄河河口二维泥沙有限元数学模型及应用(Ⅱ)--潮流和泥沙输运沉积过程模拟分析

利用多沙黄河河口潮波平面二维泥沙数学模型,通过典型时刻近海海区潮汐、河口口门河道、河海流场、含沙量、河床变形和海底等值线等图形对入海河口海域潮汐和潮流海洋动力特性、入海泥沙运动扩散输移规律、河口拦门沙形状、形成过程、泥沙冲淤和海底地形变化进行了分析,这些都与实测资料和遥感图像的分析基本一致。     

Role of external forcing on the seasonal and interannual variability of mixed layer depth over the Bay of Bengal using reanalysis datasets during 1980–2015

The monsoon reversal winds in different seasons and high influx of freshwater from various rivers make the Bay of Bengal (BoB) a unique region. Thus, the knowledge of the dynamics of the mixed layer over this region is very important to assess the climatic variation of the Indian subcontinent. A comprehensive study of the role of external forcing on the seasonal and interannual mixed layer depth (MLD) variability over the BoB is carried out for 36 years (1980–2015) using reanalysis products. A weak and strong seasonality of MLD is observed over the northern and the southern BoB (NBoB and SBoB) respectively. The partial correlation suggests that the net heat flux (Qnet) is the major contributor to the deepening of MLD over the NBoB, whereas the wind stress controls the deepening over the SBoB. The seasonal variability reveals the deepening of MLD during summer and winter monsoon and the shallowing during pre- and post-monsoon over the BoB. The relation of the interannual MLD variability and the different phases of the Indian Ocean Dipole (IOD) reveals that the negative phase of IOD is associated with deeper MLD over BoB while the positive phase of IOD depicts shallower MLD. In addition, the opposing characteristic of MLD is highly prominent during October-December. This is majorly contributed by variations related to the second downwelling Kelvin and associated Rossby waves over BoB for the opposing phases of the IOD years.     

SASW法在粉土液化判别中的应用

文章介绍了面波法(SASW法)的基本原理与测试方法,并将该方法用于判别黄河三角洲饱和粉土的液化势.通过标准贯入试验结果与瑞雷波法判别结果的对比,说明以剪切波速为土性指标的液化判别方法是一个很有前景的方法,但由于资料太少,建议继续收集液化调查资料,以发展出一个有充分根据的液化判别方法.     

声频应力波在锚杆锚固状态检测中的应用

研究了声频应力波法快速普查检测锚杆锚固状态的原理及评价分级标准,并将它成功地应用于潘一矿锚杆施工质量的检测,得出了利用声频应力波快速普查检测锚杆锚固质量的方法是切实可行和有效的。     

Dynamics of upper tropospheric stationary wave anomalies induced by ENSO during the northern summer: A GCM study

Ensemble seasonal integrations are carried out with the COLA GCM, with a view to understand the dynamical connection between warm SST anomalies in the equatorial central-eastern Pacific Ocean and the upper level stationary wave anomalies seen during drought years over the Indian summer monsoon region. In addition, experiments with and without orography are performed in order to examine the role of the Himalayas in modulating the El Niño induced stationary wave anomalies over the summer monsoon region. The GCM simulations show a statistically significant weakening of the summer monsoon activity over India in response to the SST forcing in the equatorial Pacific Ocean. This weakening of the summer monsoon appears to be largely related to modifications of the local Hadley and Walker cells over the summer monsoon region. In addition, it is seen that the anomalous ENSO divergent forcing over the tropical Pacific Ocean can act as a potential source for Rossby wave dispersion. Here one finds the possibility of meridionally propagating Rossby waves, which emanate from the ENSO forcing region, to interact with the subtropical westerlies and generate anomalous highs and lows in the subtropics and extratropics. The quasi-stationary perturbations seen over west Asia, Pakistan and northwest India during drought years, seem to be generated by the above mechanism. An alternate mechanism that could be important for the persistence of the quasi-stationary perturbations seems to be based on the dynamic excitation of middle latitude normal modes which can extract energy from the zonally varying unstable basic flow. It is seen from the GCM simulations, that the Himalayan orography plays a crucial role in anchoring the El Niño induced extratropical westerly troughs far to the west in the high latitude belt. In the absence of orography it is seen that the ENSO induced extra-tropical cyclonic anomalies tend to intrude southward into the monsoon region thereby destroying the regional scale circulations completely. Another effect due to the Himalayas is to generate lee waves on the eastern side of the topographic barrier which encircle the globe in the subtropics and midlatitudes.     

不规则波折射物理模型试验研究

作者曾发表过“不规则波折射的数学模型〔１〕。为了与数学模型的计算结果相互验证，在大连理工大学海岸及近海工程国家重点实验室进行了不规则波折射物理模型试验。试验研究结果表明：提出的“不规则波折射数学模型”对频谱采用等能量分割、对方向分布采用等间隔（Δθ＝ｃｏｓｎｔ）分割的组成波折射线性叠加法是合理的、可行的，可供港口及海岸工程规划、设计应用     

Long-Period Distribution of Wave Heights and Its Application

This paper reveals that the long-period statistic distribution of the characteristic heights of deep-water waves assumes the lognormal distribution. Thereafter, the largest wave-height which may occur in the service life of coastal structures is derived in this paper.     

黏声介质平面波有限差分叠前深度偏移及在莺歌海盆地的应用

莺琼盆地诸探区中存在底劈现象,深层气源产生的气体沿底劈产生的裂隙通道向上漫溢.漫溢过程中,一是充填在遇到的砂体中形成气藏;二是弥漫在上溢通道中,使得通道中的纵波速度发生变化,进而纵波波阻抗差异变小,反射变弱.另外,通道中气体的存在,会加强地层的吸收衰减,使得地震波振幅变弱、高频成分损失导致同相轴分辨率降低.利用OBC数据进行多波地震勘探和利用黏声介质的叠前深度偏移都是改善模糊区成像质量的重要方法技术.为此,本文提出用黏声介质平面波有限差分法叠前深度偏移成像方法改善气体充填区域的成像质量.黏声介质成像目的是补偿地震波的吸收衰减;平面波偏移成像目的是适应海上单炮数量巨大,提高波动方程叠前深度偏移成像的效率;有限差分法叠前偏移的目的是适应该区浅层气分布局域性极强、Q值的空间变化大的情况.在莺歌海某探区的实际数据上的黏声介质平面波有限差分叠前深度偏移试验证明,本方法是改善模糊区成像质量的较为有效的途径.     

伪谱法在隧道超前预测资料处理中的研究与应用

利用地震波在不同介质中的传播特性,采用伪普法对隧道掌子面的地震波记录进行处理与分析。研究结果表明逆时深度偏移计算获得的偏移剖面能够较为准确的分辨出掌子面前方构造面的分布位置,为提前预报掌子面前方的不良地质情况,确保隧道工程的合理安全开挖提供了依据。