A numerical model for far-field tsunamis and its application to predict damages done to aquaculture

The 1960 Chilean tsunami which traveled the Pacific Ocean and caused much damages to Japan is simulated from its generation to the terminal effects on coastal areas. In the computation of ocean propagation by the linear longwave theory, a new technique is introduced to keep the same accuracy as the linear Boussinesq equation and reduce the CPU time as well as the computer memory. In the coastal transformation computation, the energy dissipation due to sea-bottom scouring is suggested to be included, particularly in the case of long bays. To obtain accurate results, the current velocity requires finer spatial grids than the water surface elevation. Damage done to pearl culture rafts are explained in terms of the computed current velocity.     

基于GIS的电话号线系统图形管理模式研究与应用

在已有的MIS系统中添加GIS功能一直是GIS技术发展中备受关注的课题 ,本文主要研究在传统的号线MIS系统中增加GIS功能的方法———创建电子地图 ,其中实现的关键是图形系统与MIS系统的功能交互。文中以南京六朝号线系统为例对该方法的实现过程进行了详细的论述 ,包括体系结构 ,技术路线 ,功能框架等。GIS的强大的地图显示和查询功能与号线线路的自身特点相结合 ,应用于南京六朝号线管理系统中 ,取得了良好的社会效益。     

闽西晚中生代基性岩脉的地球化学研究

对闽西三个地区基性岩脉的地球化学研究发现,该区域的基性岩脉为亚碱性岩石系列,具有高 Al、低 Ti、Na2O > K2O的特征;相对富集大离子亲石元素,亏损高强场元素.半村辉绿岩脉和拔里角闪辉长岩脉以 Nb、Ta、Ti负异常为特征,林子坟辉长辉绿岩脉具有 Nb、Ta负异常和 Ti弱正异常.半村和拔里的岩脉稀土元素总量高,明显富集轻稀土元素,(La/Yb)N=6.8～8.4;林子坟的岩脉稀土元素总量相对较低,轻稀土元素弱富集,(La/Yb)N=2.0.结合基性岩脉的地球化学特征和区域构造演化分析,初步认为半村和拔里的基性岩脉来自与俯冲作用有关的富大离子亲石元素流体交代的富集地幔;林子坟基性岩脉是软流圈地幔部分熔融的产物,地壳混染作用是其相对富集大离子亲石元素的原因.结合玄武岩构造环境判别图解可知,半村和拔里岩脉具有的大陆边缘弧的特征并不指示基性岩脉形成的构造环境,而是说明其源区受到俯冲板片派生出来的流体交代作用.半村和拔里岩脉形成于大陆板内拉张带,林子坟岩脉形成于板内裂谷环境.与华南其他地区的基性岩脉对比表明,虽然晚中生代华南地区处于拉张的构造背景下,但是岩脉形成的构造环境与微量元素地球化学特征均有明显的差异,反映了各地区构造环境演变和地幔演化的复杂性.     

固体潮Love数的基本理论和数值结果

滞弹微椭、自转无海洋、横向均匀地球模型的固体潮模拟理论,已能很好地解释空间大地测量技术的观测成果,但这一地球模型中还没有考虑的一些物理因素(地球横向不均匀和各向异性等),目前在理论上已被人们所重视．本文在毫微伽和毫米精度上,研究了Love数的基本理论,给出了其解析表达式;利用空间大地测量技术对love数解析表达式的拟合结果,计算了2阶潮汐各个波段内的Love数．研究表明空间大地测量技术观测精度的提高,是精确测定Love数的必要途径之一．     

天池火山三期浮岩气孔形态的复杂性及其动力学成因

爆炸式喷发过程中,火山碎屑物气孔记录了挥发分出溶、膨胀和合并等信息,其大小、形态、数量密度、空间分布等局域特征是推断火山喷发动力条件的重要参考。文章基于天池火山三期喷发(50 000年前大喷发的黄色浮岩、千年大喷发的灰白色浮岩和1668年八卦庙期喷发的黑色浮岩)野外地质工作,以非线性火山喷发动力学为指导,开展了火山通道内气泡生长的流体动力学研究,揭示出岩浆流体黏性力和界面张力的共同作用对于岩浆减压和气泡生长过程的约束。在浮岩气孔结构的定量化分析基础上,进一步研究了天池火山三期喷发的浮岩气孔参数,通过气泡生长流体动力学方程得到了千年大喷发灰白色浮岩毛细管数Ca值为253, 明显高于50 000年前大喷发黄色浮岩(Ca值为94)和八卦庙期喷发黑色浮岩(Ca值为111),表明了千年大喷发曾发生过明显的成分变化,推测可能与幔源基性岩浆注入有关;而50 000年前大喷发黄色浮岩气孔不规则形态参数(1-Ω)值为0.098,大于后两期喷发(分别为0.052和0.064),可能意味着天池火山系统动力学平衡的弛豫周期变小或浮岩气泡生长受动力学、流变学改造过程减弱,这可为进一步研究天池火山活动规律提供参考。三期浮岩毛细管数Ca量级为102,气孔不规则形态参数(1-Ω)量级为10-1,从动力学上首次证实了天池火山属于普林尼型或超普林尼型喷发。     

山区公路隧道建设对地下水环境扰动评价研究

由于长大隧道建设期间具有显著地集水廊道效应,施工过程中地下水不断向隧道轴线汇集,进而诱发一系列的水文 地质灾害,给施工人员和隧址区周边的生态环境带来不可估量的损失。为此,在构建山区公路隧道建设对地下水环境扰动 评价体系的基础上,考虑到群决策不同个体实践认知水平的差异,把基于决策人员偏好信息的区间数层次分析模型用于山 区公路隧道建设对地下水的环境影响评价领域,并与模糊综合评判法进行有机结合,对西藏米拉山特长隧道建设对地下水 环境影响进行评价,结果表明,米拉山特长公路隧道建设对地下水的扰动程度属于一般水平。依据评价结果,采取了相 应的工程措施,实现了隧道建设与隧址区环境保护的协调统一,可为类似地区隧道建设的地下水环评工作提供有益的 参考。     

Studies on critical Reynolds number indices for wind-tunnel experiments on flow within urban areas

Reynolds-number dependence of flow fields within a modelled urban area was studied in a wind tunnel. We measured flow around a single model building and around model city blocks at various wind speeds, and studied Reynolds number indices more appropriate than the building Reynolds number. Our results led to the following conclusions. Firstly, the flow around the models in the wind tunnel was roughly divided into three parts according to the intensities of viscous stress and Reynolds stress as follows: (1) the flow in the vicinity of the ground or the surfaces of the model, where viscous stress became dominant under certain conditions; (2) the flow detached from the surfaces of the model, where Reynolds stress was always dominant; and (3) the flow around the separation bubble at the leading edge of the building model, where the influences of both viscous stress near the wall and the Reynolds stress in the separated boundary layer were mixed.Secondly, the critical Reynolds number of the flow in the modelled urban area could be defined by using both the roughness Reynolds number Re_z0 (= z₀u_*/) and the dimensionless height z₊ (= zu_*/). Reynolds-number independence could be expected for whole flow fields in the modelled urban areas as long as the critical values of Re_z0 and z₊ were satisfied.     

Surface-Layer Characteristics in the Stable Boundary Layer with Strong and Weak Winds

An extensive meteorological dataset obtained from the plumevalidation experiment conducted by the Electric Power Research Institute (EPRI) atKincaid during 1980–1981 is analysed for studying the characteristic differences in thesurface-layer parameters in strong and weak wind stable conditions. The surface-layerparameters are computed using the similarity functions _m and _h proposed byBeljaars and Holtslag. The weak winds are characterized using the geostrophic wind speedas well as the wind speed at the 10-m level. The surface fluxes are found to be finitein weak wind conditions.Empirical formulations for the eddy diffusivities of momentum(K_M) and heat (K_H), and drag (C_D) and heat exchange (C_H) coefficients, as powerlaw functions of the bulk Richardson number (Ri_B), are proposed under both strong andweak wind conditions. Results are close to those based on observations taken from the IndianInstitute of Technology low wind diffusion experiment, the Land surface processes experiment,the Hanford diffusion experiment, the Cabauw field experiment and the Cooperative Atmospheric SurfaceExchange Study 1999 (CASES-99) experiment. In addition, the fluxes obtained fromthe proposed empirical relations are in good agreement with those based on similarity theory as wellas the turbulence measurements taken from the CASES-99 experiment.     

山西成金中酸性侵入体研究

山西金矿与燕山期中酸性侵入岩密切相关。为从三维角度全面研究岩体，应用综合信息解译，全省圈定隐伏中酸性岩体６６个，这些岩体出露面积小，隐伏范围大，表明岩体剥蚀程度浅，成矿潜力大，据其本身及分布特点，可划分为５个岩带，１４个亚岩带。据综合信息标志，判别全省有４４个成金岩体，并举实例阐述其综合信息特征．     

北京相当暴雨日数的气候特征

根据北京99年6～8月的逐日降水资料和274年6～8月总降水量资料， 分析了相当暴雨日数与总降水量及旱涝等级的相关性，给出相当暴雨日数与总降 水量的定量关系式，建立了北京274年汛期相当暴雨日数资料序列。分析表明: 相当暴雨日数概念的引入，可以把汛期总降水量中暴雨过程降水与非暴雨过程降 水分开，证实汛期旱涝变化只取决于暴雨过程的总次数和强度；相当暴雨日数是 一个气候统计量，有与总降水量一致的周期变化，但其年际变率和3.5年周期比 总降水量更显著，其概率分布满足泊松分布；与旱涝等级比较，相当暴雨日数与 总降水量的相关性更好，且有利于研究形成汛期旱涝灾害的暴雨过程特征。