FHD-1数字化地磁观测系统常见故障维修及电源改进

主要介绍FHD-1分量质子磁力仪故障维修;通讯传输中的故障检修、UPS的检修及对供电系统的改进,分析了有关的电路及故障原因,并以实例对这些故障的检修进行了总结,提出了检修方法、步骤及改进措施。     

电阻率观测系统故障分析及维修

针对陕西省数字化地电阻率观测设备的观测数据,找出观测过程中存在的主要问题和故障现象,分析发生仪器故障的原因及处理方法;对有关的电路及故障原因进行分析,并以实例对这些故障的检修进行总结,提出检修方法、步骤及改进措施.     

陕西地震前兆台网ZD9A-Ⅱ地电场仪故障及排除

通过对陕西地震前兆台网4个地震台的ZD9A-Ⅱ地电场仪的观测资料进行了分析,对该仪器的各项工作指标、观测记录的数据甄别出异常变化形态,找出观测过程中存在的主要问题和故障现象,分析发生仪器故障的原因及处理方法;对有关的电路及故障原因进行分析,并以实例对这些故障的检修进行了总结,提出了检修方法、步骤及改进措施。     

DD—1地震仪观测记录中的故障检修

列举了ＤＤ—１地震仪在地震监测中记录通道的常见故障，用具有代表性的检修事例，介绍了对故障源的查寻及检修方法，并分析了故障产生的原因。     

螺旋CT机的维护和检修探讨

本文根据现阶段医院螺旋CT所处的环境及使用特点,对其维护检修工作按优先级分三个方面依次进行论述:首先强调加强预防性维护的重要性并综述相关内容和具体方法;随后阐述对现场即时维修的要求和应做好的准备工作;最后在分析若干实际故障解决案例的基础上总结了停机检修的经验和应注意的原则.     

地震仪器常用检修方法

介绍了检修常用地震仪器的全过程和常用的几种检修方法，并针对不同的仪器及不同的故障现象，列举了相应的的维修实例     

地震仪器常和检修方法

介绍了检修常用地震仪器的全过程和常用的几种检修方法，并针对不同的仪器及不同的故障现象，列举了相应的维修实例。     

C-ATS地电仪常见故障分析及排除

对C-ATS地电仪系统构成、工作原理和特点进行了介绍,结合维护检修经验对C-ATS地电仪常见故障的原因进行了详细分析,对故障的排除方法进行阐述,检查维护仪器的方法经验,对其它地电台站有一定的参考意义。     

昆明地震台前兆仪器雷害故障分析与检修

雷害已成为影响台站长期稳定运行的重要因素之一。通过对昆明地震台前兆观测仪器连续几年多次雷电故障现象特征、诊断修复过程、故障原因等的分析,提出了雷害故障检修的一般步骤方法。     

SD-3A型自动测氡仪故障检修

通过对SD-3A型自动测氡仪故障的检修实例,结合台站仪器维修、维护经验,分析了仪器故障原因,提出处理方法,帮助台站工作人员提高仪器维护能力。     

Non-linear three-dimensional inversion of cross-well electrical measurements

Cross-well electrical measurement as known in the oil industry is a method for determining the electrical conductivity distribution between boreholes from the electrostatic field measurements in the boreholes. We discuss the reconstruction of the conductivity distribution of a three-dimensional domain. The measured secondary electric potential field is represented in terms of an integral equation for the vector electric field. This integral equation is taken as the starting point to develop a non-linear inversion method, the so-called contrast source inversion (CSI) method. The CSI method considers the inverse scattering problem as an inverse source problem in which the unknown contrast source (the product of the total electric field and the conductivity contrast) in the object domain is reconstructed by minimizing the object and data error using a conjugate-gradient step, after which the conductivity contrast is updated by minimizing only the error in the object. This method has been tested on a number of numerical examples using the synthetic 'measured' data with and without noise. Numerical tests indicate that the inversion method yields a reasonably good reconstruction result, and is fairly insensitive to added random noise.     

ZH-1卫星观测的VLF人工源信号特征分析与全波模拟

中国地震电磁监测试验卫星张衡一号(ZH-1)已于2018年2月2日成功发射,正在开展卫星数据在轨测试,并对卫星数据质量进行判定.本文对ZH-1卫星2018年5月至6月夜侧的VLF频段电场功率谱数据进行了分析.通过分析位于不同L值、具有不同发射频率的多个VLF人工源上空的卫星重访轨道观测数据,发现ZH-1卫星记录的人工源信号电场变化标准差与DEMETER卫星记录电场变化标准差几乎一致,说明ZH-1卫星观测数据具有较好的稳定性.通过重访轨道均值与全波模型计算结果对比,发现两者在数值上较为接近,在形态上较为一致,说明ZH-1卫星VLF频段电场功率谱数据具有一定的可靠性.此外,研究了VLF人工源上空及共轭区的电场分布特征和电波传播规律,并与DEMETER卫星的结果进行了对比,结果表明VLF人工源产生的电磁辐射穿透电离层后以导管或者非导管的哨声波模向共轭区传播,因为传播过程中的朗道阻尼,共轭区的电场能量比辐射源顶空更小.VLF人工源位于L1.5时,电磁波传播更容易发生非导管传播,VLF人工源信号导管传播模式在共轭区的电场响应相对于共轭点会发生一定程度北向偏移.     

层状介质井中电测数值计算及其应用研究

采用Gauss Laguerre求积公式对层状介质井中电测地-井方式的ΔV1（电位梯度）、ρa参数进行了理论计算.大量的正演数据揭示在层状介质情况下,井中电测地-井方式观测可以获得台阶异常,与相应的地电层相对应;低阻覆盖层和中间低阻层对井中电测影响很大,厚层覆盖区对地-井方式观测不利;水槽模拟和应用实例表明,分析实测资料时,要考虑层状介质ΔV1、ρa的正常场特征,对实测数据进行正常场改正,分析正常场改正后的ΔV″1异常效果较好.     

Electric circuits of the disturbed magnetosphere-ionosphere system and their generators

The simplest theory of electric circuits is applied to analysis of the observed large-scale electric field and currents in a disturbed magnetosphere-ionosphere system. Maps of distribution of field-aligned currents (FACs) obtained from ground-based magnetic measurements using the original magnetogram inversion method (MIT) and measurements by satellites were used. A method for circuit determination according to the data of such maps based on the detection of spatial R.N inhomogeneities in each of three Iijima and Potemra FAC zones is proposed. The results of the new method are used to describe some electric field and current generators not known before, new types of current systems in tail lobes and plasma sheet, and the formation and dynamics of new types of three-dimensional systems with auroral electrojets and meridional ionospheric Pedersen current, which have not been paid due attention in the literature.     

力平衡反馈技术在石英水平摆倾斜仪中的应用研究

石英水平摆倾斜仪在前兆地震观测中得到了广泛的应用,取得了较好的观测数据,但是仍然存在一些不足,如灵敏度未知、频率特性不理想等.为解决这些问题,本文提出一种基于力平衡反馈技术的石英水平摆倾斜仪设计方法.该方法通过差动式电容换能器检测摆锤的位置信息,将其转换成电信号输出;同时通过电子线路将输出电压信号处理后反馈给摆锤,该反馈电压在摆锤上产生一静电力.根据该设计方法,我们研制了原理样机并进行了测试,结果表明,样机的灵敏度为16801V/（m·s^-2）,样机的幅度响应在从DC到5s都是平坦的.     

An Approach for Interpretation of Self-Potential Anomalies due to Simple Geometrical Structures Using Fair Function Minimization

A quantitative interpretation method of self-potential field anomalies has been proposed. The method is designed and implemented for the estimation of center depth, electric dipole moment or magnitude of polarization, polarization angle, and geometric shape factor of a buried body from SP field data, related to simple geometric structures such as cylinders, spheres and sheet-like bodies. The proposed method is based on Fair function minimization and also on stochastic optimization modeling. This new technique was first tested on theoretical synthetic data randomly generated by a chosen statistical distribution from a known model with different random noise components. Such mathematical simulation shows a very close agreement between assumed and estimated model parameters. Being theoretically proven, it has been applied and tested on self-potential field data taken from the United States, Germany, India and Turkey. The agreement between results obtained by the suggested method and those obtained by other previous methods is good and comparable. Moreover, the depth obtained by this method is found to be in high accordance with that obtained from drilling information.     

基于人工源的甚低频电磁波空间传播特征统计分析

利用2005年1月至2010年11月DEMETER卫星记录的NWC发射站的VLF电场功率谱数据,采用指数拟合的方法,分析了VLF电磁波在卫星高度激发的电场空间分布和衰减特征.研究结果表明:(1)VLF电场在发射站上空及其磁共轭区有着很强的对应关系,存在南、北2个强电场中心涡;(2)相对于发射站的位置,VLF电场中心点具有经度和纬度偏移,日侧地磁经度偏移均值大于夜侧,而地磁纬度偏移均值则小于夜侧;(3)日侧VLF电场强度呈现出周期性的年变化;(4)在VLF电场中心10°范围内,电场强度随距离快速衰减,衰减常数b在长达6年的时间内保持稳定.在以上研究结果基础上初步构建的卫星高度人工源电磁波空间分布特征,将为研究地表-电离层电磁波传播机理提供基础技术支撑.     

星载电场数据处理方法研究

给出一种新的非线性、非平稳信号的处理方法——HHT方法,并把该方法首次应用于星载电场数据处理中.以2004年9月15日菲律宾6.0级地震前两天(13日)DEMETER卫星经过震中区域上空所记录到的数据为例,对ULF频段的电场数据进行了处理,得到了相应的HHT时频图谱.另外,还利用DEMETER卫星中心网站提供的SWAN软件计算得到了相应的小波变换时频图谱,通过比较发现,虽然两种方法对异常信号出现的位置时刻的描述有相同的能力,但HHT方法在异常信号的细节描述上更为清晰,从而为今后进一步的研究工作奠定了基础.     

On the influence of DC railway noise on variation data from Belsk and Lviv geomagnetic observatories

Geomagnetic variation data from the observatories in Belsk (BEL, Poland) and Lviv (LVV, Ukraine) significantly suffer from disturbances caused by direct current (DC) electric railways. The aim of this study is to quantify the impact of these disturbances on quantities derived from such data, as the K index of magnetic activity and the induction arrow used in the geomagnetic deep sounding method to indicate lateral contrasts of electric conductivity in the solid earth. Therefore, undisturbed data have been reconstructed by means of a frequency-domain transfer function that relates the horizontal magnetic field components of the observatory to the ones synchronously recorded at a noise-free reference station. The comparison of the K index derived from original and reconstructed data shows an increase of quiet time segments by 29% for LVV and by 14% for BEL due to our noise removal procedure. Furthermore, the distribution of the corrected K indices agrees well with the one from the Niemegk observatory in Germany.     

基于站间天然电磁场单位脉冲响应的大地电磁时间序列去噪方法

针对天然大地电磁场信号在人文活动密集地区易受噪声干扰的问题,本文提出利用两个同步测点天然电磁场时间序列之间的单位脉冲响应,合成本地点受干扰时段的数据,从而去除大地电磁噪声.首先,选择高信噪比时段的数据,采用最小二乘法,估算本地点与参考点之间的单位脉冲响应,再根据卷积定律,结合参考磁场合成本地点的磁场和电场.最后用合成数据替换含噪声时段数据,实现时间域去噪.实测高信噪比数据和含噪数据的处理结果表明,该方法可以高精度合成本地点磁场与电场信号,有效去除本地点电场和磁场噪声,包括相关噪声,提高大地电磁数据质量.