西宁台地温井数字资料分析

对西宁地温井数字化资料进行了分析,认为数据稳定可靠,无外界干扰因素存在,其变化形态呈现缓慢上升的年变趋势,在汶川8．0级地震前出现明显的下降型异常变化,值得进一步关注。     

Wave dispersion in dry granular materials by the distinct element method

Numerical studies are conducted to investigate the existence of wave dispersion in resonant column tests on dry granular soil. To this end, the two-dimensional distinct element method (DEM) in the time domain is employed. The investigations focus on the effect of sample width, voids ratio, viscous damping and wavelength, on propagation velocities of longitudinal harmonic waves in rectangular samples of uniform grains. It is shown that granular materials may exhibit anomalous dispersion that is, wave velocities that increase with increasing excitation frequency. This increase may exceed 20% for squatty samples, but becomes less pronounced for slender samples. Similar findings have been reported in some experiments on granular materials, but have not been systematically explored by numerical means. Results are presented in the form of dimensionless graphs and charts that elucidate the salient features of the problem. Comparisons with findings from gradient elastodynamic and viscoelastic theories are discussed.     

Perspective on theories of non-Fickian transport in heterogeneous media

Subsurface fluid flow and solute transport take place in a multiscale heterogeneous environment. Neither these phenomena nor their host environment can be observed or described with certainty at all scales and locations of relevance. The resulting ambiguity has led to alternative conceptualizations of flow and transport and multiple ways of addressing their scale and space–time dependencies. We focus our attention on four approaches that give rise to nonlocal representations of advective and dispersive transport of nonreactive tracers in randomly heterogeneous porous or fractured continua. We compare these approaches theoretically on the basis of their underlying premises and the mathematical forms of the corresponding nonlocal advective–dispersive terms. One of the four approaches describes transport at some reference support scale by a classical (Fickian) advection–dispersion equation (ADE) in which velocity is a spatially (and possibly temporally) correlated random field. The randomness of the velocity, which is given by Darcy’s law, stems from random fluctuations in hydraulic conductivity (and advective porosity though this is often disregarded). Averaging the stochastic ADE over an ensemble of velocity fields results in a space–time-nonlocal representation of mean advective–dispersive flux, an approach we designate as stnADE. A closely related space–time-nonlocal representation of ensemble mean transport is obtained upon averaging the motion of solute particles through a random velocity field within a Lagrangian framework, an approach we designate stnL. The concept of continuous time random walk (CTRW) yields a representation of advective–dispersive flux that is nonlocal in time but local in space. Closely related to the latter are forms of ADE entailing fractional derivatives (fADE) which leads to representations of advective–dispersive flux that are nonlocal in space but local in time; nonlocality in time arises in the context of multirate mass transfer models, which we exclude from consideration in this paper. We describe briefly each of these four nonlocal approaches and offer a perspective on their differences, commonalities, and relative merits as analytical and predictive tools.     

对山西临汾中心地震台SSQ-2I数字化石英摆倾斜仪异常图像的分析

对山西临汾中心地震台SSQ-21数字化石英摆倾斜仪记录图像,从仪器自身、人为因素及地震影响等几方面进行了分类介绍与对比,从而为正确地分析异常图像提供了依据,提高了地震预测的可信度。     

单项资料异常变化信息提取的一种新方法：多点组信息法

在前人工作的基础上提出了多点组信息法，包容了以前各种各样的数据处理方法，并赋予了新的内容，以４点组斜率信息法为例，做了系统的论述，并以小水峪垂直基线资料为例，给出了初步的处理结果，证明该方法在各种数据的分析处理、提取地震前兆异常信息的应用中有较大的价值，最后给出了标准化信息流，对多项不同量纲的异常信息合成提供了方便。     

山西洪洞ML5.0地震前测震学异常指标分析

对山西洪洞2003年ML5．0地震进行了分析，发现震前1a左右，在临汾盆地周边地区相继出现断层总面积、η值、A(b)值、D值、5值、YH值等地震活动性指标异常，这些指标异常反映了5．0级地震前地震活动呈现增强的特征。根据非线性理论中的尺度依赖性原理提出一种对特定范围的中强地震进行检验性预测的方法。     

新民地震台应变短期异常与地震的关系探讨

应用新民地震台土层应变仪的观测资料，对1999年11月辽宁岫岩地震及邻近辽宁地区的中强震前的应变异常特征进行了初步分析与探讨。     

地震前红外异常的基本特征与成因机理

通过分析发生在中国及相邻地区的40多次地震的卫星热红外图像,总结了卫星红外临震异常的基本特征。对有关异常成因机理的诸家观点进行了阐述,提出了作的倾向性意见。一般情况下Ms＞5地震前均有较清晰的红外临震异常显示,低空大气－地面增温幅度显,并表现出突发性和阶段性特征。异常面积与震级的大上呈一定程度的正相关。作倾向于认为,临震大气静电异常对大气的极化作用是产生热红外异常的主要原因,异常大气的温室效应也是不可忽视的因素。     

地质实验测试异常信息提取与集成

结合具体实例探讨了地质实验测试过程中的有效信息和异常信息及异常信息提取的相关问题,阐述了地质实验测试异常信息的集成应用在地质科学研究、地质勘查和地质实验测试中的意外作用。意在强调地质实验测试技术人员应充分重视异常信息的发现、提取和集成,加强学科间的交叉与合作,推动地质实验测试水平的提高。     

海南数字地脉动参数处理系统

该文编制了一个基于服务器数据库的地脉动参数自动处理系统, 它利用FTP协议每天自动从测震台网中心的服务器中获取地脉动波形, 自动计算各个地脉动参数, 并自动把参数添加到地脉动参数数据库中。 同时编制地脉动参数查询与图形显示系统, 用户可使用IE浏览器查看地脉动参数和绘制变化图形。 初步研究认为, 在海南及邻区显著地震前和地震活动活跃时地脉动参数有一定的异常变化。