Direct and inverse problems in local electromagnetic induction

Various methods of solving direct and inverse problems in local electromagnetic induction are presented. In the section dealing with direct problems some improvments are suggested in the finite difference method in the case of two-dimensional modeling. Two ways of dealing with inverse problems are presented, the first continous, the other parametric. Emphasis is laid upon algebraic aspects of dealing with one-dimensional inverse problems.     

Analysis of palaeomagnetic time series — Techniques and applications

This review is intended to provide an introduction for the nonspecialist to concepts and techniques which are useful for analysing palaeomagnetic time series. Emphasis is placed on analysis in the frequency domain, particularly the periodogram and maximum entropy methods. The review consists of two parts dealing with techniques and applications respectively.     

Optimal design of inerter systems for the force-transmission suppression of oscillating structures

When dealing with the oscillations of fixed-base structures or machine s induced by external forces,suppre ssing the vibrational impact on the adjacent structures and the environment helps to maintain the structural durability and ensure the users ’ comfort level.This study proposed an inerter-based optimal solution to suppress the vibrational forces and energy transmitted to the suppo rting ground by utilizing the great potential of the inerter.For the exte rnal fo rce,which contains various fr...     

Study on the characteristics of rock failure strain and acoustic emission field for two parallelling faults with the same slip direction including asperities

Introduction Concerning about research on grouped-earthquake seismogenic and occurrence, at present it is only limited on the stage of the theoretical analysis and numerical model. For instance, ZHANG (1987) simulated the grouped-earthquake generation and physical mechanism making use of spring-block principle. Applying for non-linear dynamic model, referring to Chinese continental plate as object, LI, et al (1997) performed the numerical simulation on the seismogenic and occurring of group…     

RESISTIVITY INVERSION WITH A PRIORI INFORMATION*

An inversion algorithm for interpreting electrical soundings based on a probabilistic treatment of the a priori information not only includes all the previous ones, but allows consideration of the constraints between the parameters. By introducing the a priori information, a unique solution among all the equivalent ones is obtained which is coherent with the geological background. Several examples dealing with the usual problems in the automatic interpretation of the electrical soundings illustrate the advantages of this algorithm. Good results are obtained with this method.     

基于Web的地磁数据管理系统的设计

采用B／S架构,设计基于Web的地磁数据管理系统。以提高日常工作效率,改善信息环境为目标,将地磁数据由文件管理过渡到数据库管理,为地磁数据的上报、管理、应用等功能的重新整合,并向网络上迁移,提出一个系统的解决方案。同时结合工作流程再造,为本行业的信息化建设、服务水平的提高提供技术支持。     

处在高烈度区管道的抗震设计需要重视的几个问题

长输油气管道的设计参数和计算方法与一般工程有较大区别,本文着重从抗震设防标准、管道液化反应和活动断裂三个方面阐述本人的一些看法和建议,给设计人员设计埋地管道时作参考。     

Risk-Oriented Approach to Resolving Legal Controversies

Water Resources - The study focuses on the specific features of the justice dealing with the results of measuring the characteristics of safety and quality of production, works, or services. It is...     

海口市向荣村井水位数字观测资料的动态曲线重叠处理方法

动态曲线重叠法是一种数字前兆观测资料的计算机分析处理方法。用它可以把与观测环境密切相关的环境噪声通过动态曲线叠加处理办法去掉,突出展示反映地震短临异常形态的阶变、脉冲等剧变类信号。通过对海口市水位观测资料的处理检验,取得了很好的效果。该方法可以广泛应用于不同地区、不同前兆观测领域中。     

基于起伏地形平化策略的弹性波逆时偏移成像方法

随着能源和资源勘查开采工作的深入,地形强烈起伏的盆山耦合地区的地震资料处理解释技术正日益成为山地地震勘探面临的重要挑战.逆时偏移方法作为精确的地震偏移成像方法之一,能对地下结构进行高精度成像.逆时偏移的核心是地震波场延拓,由于传统的地震波场延拓技术往往基于水平地表条件,相应的方法在直接处理强地形起伏条件下的地震资料时往往存在一定的精度损失.本文引入一种精度无损的处理起伏边界的模型参数化方法：基于贴体网格的地形"平化"策略发展了与地形有关的地震波波动方程数值模拟方法,采用零延迟归一化互相关成像条件实现了起伏地表条件下的弹性波场逆时偏移成像.对工业界的标准Marmousi模型和盐丘模型进行改造,获得了相应起伏地形条件下的复杂几何模型,开展了起伏地表下的地震偏移成像数值试验.结果表明基于贴体网格"平化"策略的逆时偏移成像方法具有较高的灵活性,可适应不同类型起伏地表采集的地震资料,显示出该方法在地震勘探领域的良好应用前景.     

高压直流输电对陕西地磁观测的影响

全国范围内越来越多的高压直流输电工程投入运行,其中5条线路运行对陕西地磁观测造成一定干扰。统计2014年1月-2018年6月陕西地磁观测受高压直流输电影响情况,分析各地磁观测台受高压直流输电线路影响的特征,提出判别直流输电干扰线路的方法和应对高压直流输电干扰的建议。     

改进的一阶弹性波方程交错网格高阶差分解法

本文对董良国、马在田等人发表在<地球物理学报>上的一阶弹性波方程交错网格高阶差分解法一文进行了差分格式的改进.发现原文对一阶空间导数采用2N阶差分精度,而对高阶导数却采用简单的中心差分,即对同一方程中的各阶导数的处理存在有的采用高阶格式、有的采用低阶格式的不一致性问题,本文的改进点正是消除了这种不一致性,建立了时间和空间均为四阶精度的差分格式.该方法具有编程简便、易于计算机实现和精度较高的特点.     

Rainfall-runoff forecasting methods,old and new

Here we review the main thrusts of rainfall-runoff modelling with an eye toward the advantageous use of the massive date sets being accumulated and the modern computers capable of dealing effectively with such sets.More than a tutorial, this study is aimed at providing a unifying structure for analyzing available techniques. The closing section draws attention to the existence of an alternative methodology.     

A uniform terminology on bioinvasions: a chimera or an operative tool?

A consensual set of definitions regarding bioinvasions is essential in order to facilitate discourse among the science, policy and management communities dealing with the issue. Considering both the mode of entry and the extent of the impact of an alien species into a new environment, a set of key terms is proposed as an operative tool for marine scientists.     

UPS设备对测震台站信号影响的分析

根据测震台站供电技术系统的实际问题,分析了由于UPS供电导致部分测震台站信号畸变的原理,给出处理类似问题的参考意见,对提高测震台站数据可用性将起到一定作用。     

A finite-volume approach for 2D magnetotellurics modeling with arbitrary topographies

A novel finite-volume approach for complicated 2D magnetotellurics (MT) problems with arbitrarily surface topography is presented. An edge-surface integral balance equation is derived by employing a conservation law on the generalized 2D MT boundary value problem. A triangular grid is used to discretize the 2D conductivity model so that we can deal with arbitrarily complex cases with surface topography. The node-centered finite-volume algorithm is used to derive the final system of linear equations on a dual mesh of the triangular grid, which is solved by a robust direct solver. Three synthetic models verify the accuracy of the presented finite-volume algorithm and its capability of dealing with surface topography.     

A SPH simulation on large-amplitude sloshing for fluids in a two-dimensional tank

Smoothed particle hydrodynamics(SPH) is a mesh-free adaptive Lagrangian particle method with attractive features for dealing with the free surface flow.This paper applies the SPH method to simulate the large-amplitude lateral sloshing both with and without a floating body,and the vertical parametrically-excited sloshing in a two-dimensional tank.The numerical results show that the SPH approach has an obvious advantage over conventional mesh-based methods in handling nonlinear sloshing problems such as violent fluid-solid interaction,and flow separation and wave-breaking on the free fluid surface.The SPH method provides a new alternative and an effective way to solve these special strong nonlinear sloshing problems.     

日本防止火灾措施和灭火新技术

文章综合介绍了地震国日本应付震后火灾的相应措施及此方面的部分先进技术，以供我国的防灾、消防工作者参考。     

Uncertainty in levee heights and its effect on the spatial pattern of flood hazard in a floodplain

Levees are not usually built to a uniform height due to the varying priority of protecting urban and agricultural lands and they are often maintained in segments. Ad hoc alteration of the heights of these segments may aggravate flood conditions. Alterations lead to complex feedback loops in velocity and depth of water that are difficult to predict. A large number of possible configurations of the levee segments renders a deterministic modelling approach ineffective. The current analysis, based on a two-dimensional hydrodynamic model involving 1000 Monte Carlo realizations of randomly varying levee heights in segments, presents a methodology of dealing with the effect of uncertainty in levee heights on the inundation pattern in a probabilistic framework. Spatially distributed model outcomes include the likelihood of inundation, range and standard deviation of flood depths and maximum speed of water. The results indicate the necessity of adopting a probabilistic approach for robust flood hazard assessment when dealing with levee segments with uncertain heights.

EDITOR M.C. Acreman; ASSOCIATE EDITOR H. Kreibich     

长春台体应变仪器观测到的地球基频球型振荡

本文分析了2004年12月26日苏门答腊M9．0级大地震后5天的长春台体应变观测资料,利用功率谱密度估计方法,在没有对资料进行去固体潮处理的情况下,较准确地获得了大地震激发的基频球型振荡,并与地球初步参考模型（PREM）的理论自由振荡频率进行了对比,发现实测振荡频率与PREM预测的振荡频率基本符合。