基于离散裂隙网络模型的节理岩体渗透张量及特性分析

节理岩体几何结构非常复杂,研究其渗流特性对于指导含水岩层稳定性分析具有重要价值。应用离散裂隙网络模型DFN方法,基于VC++6.0软件平台,建立了平面渗流分析方法,分析了节理岩体不同几何分布情况下的渗透率张量特征,通过定义渗流定向性系数对岩体渗流的定向性特征进行了定量分析。结果表明：单组节理岩体渗流具有明显的各向异性特征,渗流定向性随着节理角度变化显著;节理随着节理贯通性增加,节理渗透率呈现对数增加趋势;两组节理情况下,各向异性特征随着节理组间夹角变化;两组节理岩体渗流特征研究中,正交分布下,岩体仍存在各向异性,但渗流定向性系数较低;当节理倾角服从正态分布时,随着节理倾角标准差增大,渗透率增加;两组节理夹角不同时,节理渗透主方向倾角随着夹角增大而相应增大,基本沿两组节理夹角方向的角平分线方向。     

Characterization of hydraulic suitability of Chinese sturgeon (Acipenser sinensis) spawning habitat in the Yangtze River

Hydrodynamic flow fields affect the ecological processes such as the water diversity and the distribution of organisms. Understanding the hydrodynamic and ecological processes is critical for the restoration and protection of especially fragile ecological habitats in river systems. This study uses turbulent flow to characterize the ecological behaviour of Chinese Sturgeon (Acipenser sinensis) in the Yangtze River. The Delft3D‐Flow model, which is first validated with field‐measured data, is used to simulate the flow field within spawning habitats of Chinese Sturgeon, downstream of Gezhouba Dam. The model‐simulated turbulent kinetic energy (TKE) and its distribution pattern are then used to characterize the hydraulic environment of the fish's spawning habitat. For the spawning habitat, downstream of Gezhouba Dam, the lower limit of TKE for the Chinese Sturgeon egg mass field is 0.025 m²/s², which occurs at a velocity less than 1.7 m/s. Chinese Sturgeon prefers habitats with TKE range of 0.010 ~ 0.015 m²/s² for resting. This suggests that discharge regimes provide the basis for ecological regulation of the Three Gorges Reservoir and the scientific reference for river management. Copyright © 2011 John Wiley & Sons, Ltd.     

山东及邻区地震的重新定位及其与活动构造的关系

对山东及其邻区1975～2010年发生的地震经震相到时数据校正后,用双差定位(Hypodd)和Hypoinverse 2000定位法对其进行重新定位,分析结果表明:重新定位的地震在空间分布上与区域构造结合更为紧密,震源深度的分布与人工地震勘探所推测的断裂相吻合;研究区地震多发生在5 ～25km深度范围内,分别在10km和16km左右存在两个明显的优势分布层,推断为这两个优势分布层分别位于上地壳底面和中地壳;地震活动图像表明中强震易发生在上下地壳交界的脆-韧转换带内,是区域应力作用下深部构造动力与浅层断裂运动变形的结果.     

山西数字地震台网仿真前后震级偏差对比分析

选取山西数字地震台网2010年不同震级,不同地点的地震事件,按照中国地震局的编目要求对波形进行WA仿真处理,对比仿真前后的震级大小,找出其中存在的偏差,为地震资料的衔接提供参考.     

风光发电系统在无人值守地震台站的设计

风光互补发电技术在边防、通信、公路等已得到广泛应用,能否将这一绿色、清洁、可再生能源应用于地震无人值守台站,山东省在龙口地震台已做先期试点,通过一年试运行,风光互补发电系统能够满足地震无人值守台站的工作要求。     

基于虚拟技术的地震应急指挥技术系统应用

地震应急指挥技术系统的特殊性要求整个系统必须具有高可靠性及稳定性.基于虚拟技术的地震应急指挥技术系统可实现整个系统的容灾备份,并通过虚拟机特性将原来在多台服务器上部署的系统在一台高性能服务器上实现,节约资源的同时,使异地移植更加灵活.基于虚拟技术的地震应急指挥技术系统,可提升整个系统的稳定性、灵活性、可靠性.     

山东区域地电场观测质量分析

对7个台的观测数据质量进行评价和分析,结果表明:郯城、菏泽、大山和陵阳地震台数据质量较好,精度较高,可为地震研究提供可靠的数据资料.     

海洋地磁参量实时测量野值的在线辨识与改正

地磁参量实时测量野值的在线辨识与改正是影响地磁导航算法定位概率和精度的重要因素.地磁导航定位的研究目前主要集中于匹配定位算法,地磁参量实时测量数据处理的研究较少.本文将多层递阶非平稳时间序列预测模型引入海洋地磁参量实时测量野值在线辨识与改正,利用多层递阶模型对实时测量值进行一步预测,根据迪克松准则进行野值辨识,利用中值滤波和一步预测值对野值进行改正.仿真数据和实测数据的实验室仿真结果表明,本文提出的野值在线辨识与改正算法不仅可以检测全部孤立型野值而且对多数斑点型野值也有较好的辨识效果,对产生野值处信号的复原误差小于5%.     

The effects of dam construction and precipitation variability on hydrologic alteration in the Lancang River Basin of southwest China

This paper presents an evaluation of the spatio-temporal patterns of hydrologic alteration induced by dam construction and precipitation variability in the Lancang River Basin of southwest China from 1957 to 2000. Analyses were conducted using the linear regression method, the Mann–Kendall test, and the Range of Variability Approach. The results indicate that there was considerable variation in the average monthly precipitation between the pre- and post-dam periods in the Lancang River Basin. Second, the magnitude of monthly runoff was strongly related to precipitation, which showed an up-down annual variation, and was significantly altered by dam construction and precipitation variability. In the modified series (hydrologic series with the precipitation impacts removed), runoff deviations between the pre- and post-dam periods became larger. Third, the extreme runoff cycles were influenced by dam construction and precipitation variability downstream from the dam, and the monthly maximum runoff increased from the pre-dam to post-dam period at all hydrologic stations. Fourth, the degree of hydrologic alteration (DHA) indicates that the precipitation variability not only affected the hydrologic regime of unregulated river reach but also modified the negative impacts of dam construction, which could provide a modest mitigation of the hydrologic alterations induced by dam construction, possibly decreasing the level of DHA. Last, the overall degree of hydrologic alteration in the observed series reached 25.2, 25.3, and 29.1 % for the upstream, midstream, and downstream areas, respectively. These results show that the hydrologic regimes of the Lancang River during the 1957–2000 period were affected by damming and precipitation variability, but the hydrologic alteration was relatively low in the upstream areas of the river without a dam.