伴随数据同化法反演涌潮河口开边界   总被引：3，自引：1，他引：3       下载免费PDF全文

陈耀登  王如云  李未  卢长娜 《水科学进展》2007,18(6):829-833

构造了非线性守恒型浅水方程的伴随方程,并给出无结构三角网格的开边界校正表达式,利用Godunov格式和Riemann间断解Roe通量格式的设计思想,建立了无结构三角网格有限体积法的伴随开边界反演模型。进行了概化涌潮河口和钱塘江涌潮河口M2分潮开边界反演的数值实验,经过同化得到开边界上振幅的平均误差分别为0.000 6 m和0.053 3 m,证实了本文构造有限体积伴随模型的可行性,也表明本模型能够适应间断解问题。  相似文献   

浅层地震勘探资料地质解释过程中值得重视的问题   总被引：5，自引：5，他引：5  

杨晓平  郑荣章  张兰凤  陈献程  马文涛  徐锡伟  王瑞光  梁辉  王琰 《地震地质》2007,29(2):282-293

浅层地震勘探是第四系覆盖区隐伏断层活动性研究常用的手段,叠加剖面上反射波组的分叉、合并、弯曲、中断、尖灭等被用作判断断层存在的重要标志。松花江北的吕刚屯、巨宝屯浅层地震叠加剖面上,T0为下更新统砂砾石层等松散堆积和白垩系砂岩、泥岩的分界面,反射波组清晰。T0-1波组为砂砾石层和黏土层、或砂砾石层和粉细砂层的反射界面,反射波组振幅大,能量强。根据地震反射剖面和测线上的钻孔资料,认为阿什河断层错断了下更新统下段,滨州断层错断了上更新统下段。而通过建立高精度的钻探联合地质剖面、地层年代测试和地层对比,确认阿什河断层没有错断第四系,滨州断层错断了下更新统下段。最后,从第四系的岩性、厚度变化等解释了浅层地震叠加剖面上反射波组的中断、弯曲并非断层活动的结果,而是由第四纪地层相变引起的  相似文献   

近年长江口北支涌潮变化及其成因分析          下载免费PDF全文

张静怡  胡震云  黄志良 《水科学进展》2007,18(5):724-729

长江口北支的围垦使北支上、中段形成了河宽沿程变率较小的弯曲河槽,沿北支北岸的深槽水深条件得到改善,减弱了涌潮发生的条件,导致青龙港涌潮自2003年以来大为减弱。通过引进局部地形指数,建立了局部地形指数与青龙港平均涨率之间的良好相关关系。研究表明,青龙港平均涨率的年际变化与人类活动(围垦)在北支的进程以及青龙港附近的局部地形变化相应,并认为对于复式断面,采用全断面水力指标并不能很好地反映局部地形对涌潮的影响。由于长江口北支涌潮的近年变化将对长江南、北支分流点水域的河床演变产生重大影响,因此本研究对北支的航道整治和岸线开发利用具有现实意义。  相似文献   

新疆土层应力地震异常类型初步分析   总被引：1，自引：0，他引：1  

蒋靖祥  杜文平  张进  张立新  周新 《内陆地震》2007,21(1):29-38

自1998年8月起,新疆地区开展土层钻孔应力测量,先后建成7个台。期间在新疆及邻区,多次发生中、强震。在部分地震前,应力仪记录到了异常,其异常类型大致有3种:(1)年变畸变型,主要表现为打破年变规律的畸变,异常时间在3个月以上;(2)阶变型异常,以快速跃变为特点,一般幅度较大;(3)波动型异常,以张压交替变化为显著特点。随着新疆土层应力测量资料的不断积累和震例的逐步增多,依据其异常类型特征有可能对地震三要素的预测有所帮助。  相似文献   

基于AO的钻孔柱状图的绘制   总被引：2，自引：0，他引：2  

毛爱芹  邓彩群  周荣福 《测绘科学》2008,33(1):205-207

本文针对传统手工绘制钻孔柱状图普遍存在的成图慢、效率低,难以满足实际生产的需要等许多不足之处而开发的一个应用程序。在ArcMap内置的VBA环境下调用AO的一些接口函数完成柱状图的绘制,然后调用岩层符号化功能模块,对柱状图进行填充处理,应用起来非常方便。  相似文献   

Assessment of hydrodynamic competence in extreme marine events through application of Boussinesq–Green–Naghdi models     

《Applied Ocean Research》2017

Here in present work, rotational Boussinesq–Green–Naghdi models were applied to assess the hydrodynamic intensity through the study of the boulder transport in east coast of Philippines during typhoon Haiyan and damage to coastal residences in New Jersey coast due to hurricane Sandy. The hydrodynamic forces were quantitatively analyzed and correlated to both boulder transport distance and the structural damage state in the two cases. The boulder transport was found initiated at vicinity of infragravity swash bores. Inertial force generated by the acceleration in front of the bore was found increasingly large as boulder sizes increased therefore far from negligible as in some other literatures. Besides, transport distances were highly sensitive to wave-heights and boulder sizes, so that onshore positions might be a viable approach of identifying rough magnitudes of paleostorm before other information is available. Fragility functions to predict the damage state of coastal residences due to runups was derived and preliminary validated. Water velocity and the shielding parameter were identified as major predictors of damage while free board and water depth are relatively insignificant. Due to the relative lack of wind damage observed, nearshore hydrodynamics featuring instantaneous nonhydrostatic impact might be the persistent cause of massive littoral processes and low-level structural failure in coastal regions during extreme marine events. Nonhydrostatic phase-resolving models such as Boussinesq-type models would be necessary complements for the intermediate-scale assessment of marine hazards in coastal ocean.  相似文献   

TSP203超前地质预报系统在龙潭隧道中的应用     

孙克国  李术才  张庆松 《岩土力学》2006,27(Z1):389-392

TSP203 plus系统是瑞士Amberg工程技术公司最新研制,并已经拥有专利的隧道地震探测仪器,专门为隧道的超前地质预报而设计。介绍了TSP203 plus超前地质预报系统的技术特点和基本测量原理,结合沪－蓉西高速公路龙潭隧道的实例,对照超前地质探孔与实际开挖情况,分析了该系统的实用性和可信性以及在指导施工方面起到的重要作用。  相似文献   

Mesospheric bore events in the equatorial middle atmosphere     

J. Fechine  A.F. Medeiros  R.A. Buriti  H. Takahashi  D. Gobbi 《Journal of Atmospheric and Solar》2005,67(17-18):1774

An all-sky CCD imager designed to measure wave structure of the OH, O₂b(0,1) and OI557.7 nm airglow emission layers in the mesosphere and lower thermosphere (MLT) region has been operated near the equatorial region at São João do Cariri (Cariri), Brazil, (7.5°S, 36.5°W). A large number of gravity wave was observed from September 2000 to September 2002 and among them 64 wave events were identified as mesospheric bores. The bore front shows a horizontal extension greater than 1000 km, and observed in the airglow layers as a complementary brilliance between the three emissions. At the first time mesospheric bore events were observed and analyzed in the equatorial region. Their predominant characteristics, occurrence, local time dependency, morphology and propagation direction will be presented and discussed.  相似文献   

基于文献计量法的涌潮研究动态分析   总被引：1，自引：0，他引：1       下载免费PDF全文

张舒羽  丁涛  刘进宝  胡玉珊 《海洋学研究》2022,40(1):89-100

以中国知网(CNKI)和Web of Science核心合集数据库为数据源,采用文献计量学方法,借助CiteSpace可视化分析软件,对国内外研究涌潮的国家、机构、作者、载文期刊及关键词等进行分析.在CNKI共检索出433个研究机构的632名作者在239种刊物上发表的652篇文献(1964—2020年),"钱塘江河口"...  相似文献   

Production and Certification of a Unique Set of Isotope and Delta Reference Materials for Boron Isotope Determination in Geochemical,Environmental and Industrial Materials     

Jochen Vogl  Martin Rosner 《Geostandards and Geoanalytical Research》2012,36(2):161-175

Isotopic reference materials are essential to enable reliable and comparable isotope data. In the case of boron only a very limited number of such materials is available, thus preventing adequate quality control of measurement results and validation of analytical procedures. To address this situation a unique set of two boron isotope reference materials (ERM‐AE102a and ‐AE104a) and three offset δ¹¹B reference materials (ERM‐AE120, ‐AE121 and ‐AE122) were produced and certified. The present article describes the production and certification procedure in detail. The isotopic composition of all the materials was adjusted by mixing boron parent solutions enriched in ¹⁰B or ¹¹B with a boron parent solution having a natural isotopic composition under full gravimetric control. All parent solutions were analysed for their boron concentration as well as their boron isotopic composition by thermal ionisation mass spectrometry (TIMS) using isotope dilution as the calibration technique. For all five reference materials the isotopic composition obtained on the basis of the gravimetric data agreed very well with the isotopic composition obtained from different TIMS techniques. Stability and homogeneity studies that were performed showed no significant influence on the isotopic composition or on the related uncertainties. The three reference materials ERM‐AE120, ERM‐AE121 and ERM‐AE122 are the first reference materials with natural δ¹¹B values not equal to 0‰. The certified δ¹¹B values are ?20.2‰ for ERM‐AE120, 19.9‰ for ERM‐AE121 and 39.7‰ for ERM‐AE122, each with an expanded uncertainty (k = 2) of 0.6‰. These materials were produced to cover about three‐quarters of the known natural boron isotope variation. The ¹⁰B enriched isotope reference materials ERM‐AE102a and ERM‐AE104a were produced for industrial applications utilising ¹⁰B for neutron shielding purposes. The certified ¹⁰B isotope abundances are 0.29995 for ERM‐AE102a and 0.31488 for ERM‐AE104a with expanded uncertainties (k = 2) of 0.00027 and 0.00028, respectively. Together with the formerly certified ERM‐AE101 and ERM‐AE103 a unique set of four isotope reference materials and three offset δ¹¹B reference materials for boron isotope determination are now available from European Reference Materials.  相似文献