云南部分水位观测点模拟与数字化并行观测资料对比分析

通过对云南4个水位观测点模拟与数字化并行观测资料的对比分析,认为同一个观测点的模拟与数字化观测数据内在质量接近、数据相关性好、数据的变化形态及地震同震响应特征相似,在这些并行观测的观测点上数字化观测可以取代模拟观测.     

LaCoste & Romberg ET型重力仪数字静电反馈系统的研制

介绍以计算机技术和采用数字比例积分微分控制器控制算法研制的数字式静电反馈系统的工作原理,并将该系统用于LaCoste & Romberg(LCR)ET20型重力仪的升级改造中.改造后LCR ET20重力仪的观测结果表明,该系统能解决模拟静电反馈系统中线性度不易调整和长期稳定度差等问题,并能提高重力仪的观测精度.     

基于轨道改正的卫星电视时间传递

利用在模拟卫星电视信号中插入的时间信息可实现时间传递,但由于它常采用固定的卫星位置,限制了时间传递精度。为此,研究了基于轨道改正的卫星电视时间传递方法,并给出了在轨道改正的基础上实现单向和共视时间传递的计算公式。将该方法应用于我国的模拟卫星电视时间传递中,计算了从中央电视台到国家授时中心的单向时间传递结果。     

Estimation of the Cenozoic Strike-slip Displacement for Major Faults in the Liaodong Bay Depression and its Geological SignificanceEI北大核心CSCD

Estimation of the strike-slip displacement of faults in basins or covered regions has always been a hot and knotty issue. Based on the fine interpretation of 3D seismic data, we estimated the strike-slip displacements of the Cenozoic evolutionary stages of the main faults in the Liaodong Bay Depression, and analyzed their geological significance, using methods of physical modeling experiments and structural analysis. The results showed that two thirds of the strike-slip displacements of the major faults were converted into the horizontal displacement of those secondary extension faults in the Liaodong Bay Depression. It should be noted that the Liaodong Bay Depression isn't a pure strike-slip basin, and its Cenozoic evolution also influenced by extension, thus, extension amount produced by mantle upwelling should be detracted. Strike-slip movements were generated in the depositional stage of the first and second members of the Shahejie Formation, and the strike-slip displacements of major faults in different evolution stages vary considerably. In terms of the Cenozoic cumulative strike-slip displacement, the displacement of faults in the Liaozhong Sag is the largest, followed by those in the Liaodong Sag, and those in the Liaoxi Sag is the smallest. Among all of the faults, the Liaozhong1 fault had the largest strike-slip displacement. As to the displacement in different stages, the strike-slip displacement of all major faults showed the largest displacement in depositional stage of the Dongying Formation. The Neogene strike-slip displacement of faults is bigger than that of the depositional stage of the first and second members of the Shahejie Formation in the Liaoxi region, while it showed an opposite trend in the eastern Liaodong Bay Depression. The difference of relative strength between extensional and strike-slip stress controlled the difference of structural styles and basin structures in different evolution stages and structural locations in the Liaodong Bay Depression. The Cenozoic strong strike-slip effects in the Liaozhong and Liaodong Sag were presented by the obvious strike-slip characteristics on major faults and structural styles. In the Liaoxi Sag, the obvious “extension strike-slip” superimposed structural style was caused by the extension effects in the early Paleogene and strike-slip effects of the Dongying Formation and Neogene. © 2018, Science Press. All right reserved.     

从一个野外试验看不同检波器的差异——以DSU3与20dx为例

数字检波器是近年来发展起来的一种新型检波装置.为了对比数字检波器与普通模拟检波器的差别,我们选择数字检波器DSU3与模拟检波器20 dx进行了一个针对性的野外试验.从试验结果上来看,二者主要存在四个方面的差异.通过分析差异的原因,我们认为模拟检波经过多年的应用,从理论认识到实践操作都非常成熟,但是存在容易受到电磁干扰、信号串音、漏电等现象;同时,即使经过‘类检波器反褶积’后,模拟检波器仍然难以补偿数据的‘极低频’部分;模拟检波器的灵敏度有待于进一步提高,以便降低电噪声在全部信号中所占的比例,提高信噪比;数字检波器确实在电学指标方面取得了一些进步,尤其在灵敏度、线性畸变、线性频带范围、适量保真度等方面;但是,数字检波器在耦合效应,一致性、稳定性或者抗干扰能力均存在一些问题.同时,在石油勘探中‘强噪音’以及‘多次覆盖’的双重背景下,受当前处理能力的限制,检波器电学性能方面的‘极高指标’,并不能保证地震数据的‘极高质量’.我们的研究表明:使检波器更小、更轻、更好耦合的努力与电学指标的改进具有同等重要的意义;具有良好的电学性能,更好的耦合参数,稳定性好,耐用,价格合理的检波器是我们追求的目标.     

汶川8.0级地震及其强余震引起的唐山井水位同震响应特征分析

统计了汶川8.0级地震及其强余震引起的唐山井水位同震变化的幅度参数（最大振幅、阶变量）和时间参数（最大振幅时刻,同震持续时间）,以及邻近的陡河台记录的地震波的体波和面波的到时．计算分析了同震参数与震级（ML,MS和MW三种震级）、井-震距、震源深度的相关方程及同震参数间的相关关系．结果表明,同震变化量与MS震级的相关性最好,与震源深度和井-震距相关性较弱;同震最大幅度与同震阶变量、同震持续时间相关性很高,水位同震振荡和阶变均来自地震波引起的动应变;水位同震振荡的最大振幅发生在S波至瑞利波时段,水位同震响应是地震波与水文地质环境等多种因素共同作用的结果．      

一种由一维反演初步解释二维电阻率构造的方法

利用对非水平层状介质的地质结构首先进行二维模型的正演模拟,尔后对模拟曲线再进行一维反演来确定层状结构特征,实现由一维反演初步解释二维电阻率构造的解释过程。通过对三个不同结构特征的二维模型的解释结果表明,采用这种方法能够解释简单的二维电阻率构造,尤其是对于确定存在横向电阻率差异的界面效果更好;而且利用一个简单的经验公式在等值线断面图上通过求解截止电阻率值达到确定异常体的几何形态     

Source Parameters of Old Earthquakes: Semi-Automatic Digitization of Analog Records and Seismic Moment Assessment

Recovering seismic information contained in old analog records could increase our knowledge of seismic source characteristics and the seismicity of a region. This is particularly important in zones with low to moderate seismicity.To extract the available information, it is necessary to digitize the seismic records. This is not an easy task especially owing to the generally poor quality of the original records, with illegible or missing parts. However some exceptions were found in the records of a few seismological stations in Germany, Sweden and France.This paper presents an example of the recovering of source parameters and can be divided in two parts: the first one presents a simple semi-automatic technique for digitization of old analog seismic records, developed using commercial software on a PC; the second part describes the methodology of assessing the seismic moment, using empirical and theoretical relations, as well as the seismic source dimensions.The earthquake selected to illustrate this procedure is the 23 April 1909 Benavente (Portugal) earthquake. This earthquake occurred in the Lower Tagus Valley region and caused great destruction in the meizoseismal area. It is the biggest earthquake that occurred during this century in the central part of the country and its magnitude has been estimated between 6.6 and 7.6.The digitization procedure allowed the recovery of seismic information contained in old analog records, in particular, the seismic moment estimation. The results obtained indicated that 7.6 was a very high value for the magnitude of the 23 April 1909 earthquake, suggesting that the magnitude reported in the Portuguese catalogue is overestimated. The estimated moment magnitude is 6.0.     

采用随机模拟技术与常规水文方法相结合的洪水过程模拟法

随着江河上兴建的水利工程日渐增多,流域的防洪规划和防洪调度工作,正在从以个别工程为主要研究对象转向以全流域复杂库群为研究对象。常规水文方法很难反映这种复杂流域的水文特性,在工程实践中其局限性越来越突出。随着计算机运算能力的提高,径流的随机模拟技术逐步得到研究和应用。本文分析了常规水文方法与纯数学随机模拟技术的不足,并提出了一种新的、简单易行的模拟全流域洪水的模拟方法,该方法已应用于太子河流域的库群联合防洪调度中,并取得了较好的成果。     

张家口地震台地形变数字化与模拟资料对比研究

介绍了张家口地震台的基本现状及形变数字化仪器的改造情况。从长期趋势、短期趋势和固体潮形态变化等方面,对地形变模拟观测和数字化观测资料进行了对比,对资料的连续性、稳定性、一致性和固体潮观测精度进行了分析,得出数字化资料总体评价。并针对数字化观测存在的问题提出了具体建议。