分形几何与地球科学（续完）

分形几何与地球科学（续完）陈颙（国家地震局，北京１０００３６）·ＴｏｐｉｃａｌＬｅｃｔｕｒｅ·（７）ＦＲＡＣＴＡＬＧＥＯＭＥＴＲＹＡＮＤＧＥＯＳＣＩＥＮＣＥ（ＥＮＤ）￥ＣｈｅｎＹｏｎｇ（ＳｔａｔｅｓｅｉｓｍｏｌｏｇｉｃａｌＢｕｒｅａｕ，Ｂｅｉｊｉｎｇ...     

地震学研究联合会（IRIS）研究工作进展概述

介绍了ＩＲＩＳ的研究计划和项目：①全球地震台网（ＧＳＮ）;②大隅岩石圈台阵地震研究计划（ＰＡＳＳＣＡＬ）;③数据管理中心（ＤＭＣ）全球数据管理系统（ＤＭＳ）;④教育与扩展计划（Ｅ＆Ｏ）;⑤海洋地夺台网（ＯＳＮ）。概述了ＩＲＩＳ跨世纪规划和项目研究的最新进展情况。     

新一代中国数字地震台网（NCDSN）台站系统

以白家疃数字地震台为例，介绍了新一代中国数字地震台网（ＮＣＤＳＮ）台站系统的各种硬件单元及它们的相互联系与特征。同时介绍了系统的频率响应、数据流和动态范围，并与中国数字地震台网（ＣＤｓＮ）—期设备进行了简单比较。     

分形几何与地球科学（续）

分形几何与地球科学（续）陈颙（国家地震局，北京１０００３６）·ＴｏｐｉｃａｌＬｅｃｔｕｒｅ·（３）ＦＲＡＣＴＡＬＧＥＯＭＥＴＲＹＡＮＤＧＥＯＳＣＩＥＮＣＥ（ＣＯＮＴＩＮＵＯＵＳ）￥ＣｈｅｎＹｏｎｇ（ＳｔａｔｅｓｅｉｓｍｏｌｏｇｉｃａｌＢｕｒｅａｕ，Ｂ...     

分形几何与地球科学（续）

分形几何与地球科学（续）陈顒（国家地震局，北京１０００３６）·ＴｏｐｉｃａｌＬｅｃｔｕｒｅ·（６）ＦＲＡＣＴＡＬＧＥＯＭＥＴＲＹＡＮＤＧＥＯＳＣＩＥＮＣＥ（ＣＯＮＴＩＮＵＯＵＳ）￥ＣｈｅｎＹｏｎｇ（ＳｔａｔｅｓｅｉｓｍｏｌｏｇｉｃａｌＢｕｒｅａｕ，Ｂ...     

分形几何与地球科学（续）

分形几何与地球科学（续）陈（国家地震局，北京１０００３６）·ＴｏｐｉｃａｌＬｅｃｔｕｒｅ·（４）ＦＲＡＣＴＡＬＧＥＯＭＥＴＲＹＡＮＤＧＥＯＳＣＩＥＮＣＥ（ＣＯＮＴＩＮＵＯＵＳ）￥ＣｈｅｎＹｏｎｇ（ＳｔａｔｅｓｅｉｓｍｏｌｏｇｉｃａｌＢｕｒｅａｕ，Ｂｅ...     

分形几何与地球科学（续）

分形几何与地球科学（续）陈颙（国家地震局，北京１０００３６）·ＴｏｐｉｃａｌＬｅｃｔｕｒｅ·（５）ＦＲＡＣＴＡＬＧＥＯＭＥＴＲＹＡＮＤＧＥＯＳＣＩＥＮＣＥ（ＣＯＮＴＩＮＵＯＵＳ）￥ＣｈｅｎＹｏｎｇ（ＳｔａｔｅｓｅｉｓｍｏｌｏｇｉｃａｌＢｕｒｅａｕ，Ｂ...     

分形几何与地球科学（续）

分形几何与地球科学（续）陈颙（国家地震局，北京１０００３６）·ＴｏｐｉｃａｌＬｅｃｔｕｒｅ·（２）ＦＲＡＣＴＡＬＧＥＯＭＥＴＲＹＡＮＤＧＥＯＳＣＩＥＮＣＥ（ＣＯＮＴＩＮＵＯＵＳ）￥ＣｈｅｎＹｏｎｇ（ＳｔａｔｅｓｅｉｍｏｌｏｇｉｃａｌＢｕｒｅａｕ，Ｂｅ...     

地震数据处理中Turbo C与Foxbase（Dbase）的接口技术

地震数据处理中ＴｕｒｂｏＣ与Ｆｏｘｂａｓｅ（Ｄｂａｓｅ）的接口技术在地震综合预报、地震科研及工程地震领域，时常要与地震数据库系统打交道。尽管Ｆｏｘｂａｓｅ（或Ｄｂａｓｅ）具有很强的数据处理能力，应用非常广泛，但它毕竟是数据管理语言，在复杂计算、图形等...     

MATHEMATICAL MODEL OF OVERLAND FLOW AND MECHANISM OF SOIL CONSERVATION FOR FORESTED STEEP HILLSLOPE－－（II）Mechanism of Soil Conservation Over Steep Hillslope

ＭＡＴＨＥＭＡＴＩＣＡＬＭＯＤＥＬＯＦＯＶＥＲＬＡＮＤＦＬＯＷＡＮＤＭＥＣＨＡＮＩＳＭＯＦＳＯＩＬＣＯＮＳＥＲＶＡＴＩＯＮＦＯＲＦＯＲＥＳＴＥＤＳＴＥＥＰＨＩＬＬＳＬＯＰＥ－－（ＩＩ）ＭｅｃｈａｎｉｓｍｏｆＳｏｉｌＣｏｎｓｅｒｖａｔｉｏｎＯｖｅｒＳｔ...     

模块化外框内箱结构抗震性能分析

基于《集装箱模块化组合房屋技术规程》中的要求,为提高模块化集装箱建筑的抗震性能,增加房屋的使用高度,提出了一种外框内箱结构,其由外框柱、外框梁和模块化集装箱拼装组成。为验证外框内箱结构的抗震性能,对六层传统集装箱结构和外框内箱结构进行了数值仿真分析,对比分析两种结构的层间位移角和构件应力分布等。结果表明:外框内箱结构竖向刚度分布均匀,受力更加合理,传力更加明确,能有效地减小内部集装箱构件内力,其能更好的实现结构"强柱弱梁和强节点"需求,提高结构的安全性和可靠性。     

希腊VAN地震预报方法的进展与争论(I)——进展

该文综合希腊ＶＡＮ小组成员及各国专家发表的有关论文,全面介绍了ＶＡＮ小组自８０年代初以来所进行的地电地震预报方法的探索和效果,包括观测技术、预报程序、地震三要素的估计、预报及对应情况,国际上的评价及争论等。全文包括两部分,即进展和国际评价与争论,本文是其中的第一部分。     

层状场地中透镜体对地震动影响的基本规律

本文采用有限元方法研究层状场地中透镜体对地震动影响的基本规律,分析层状场地与均匀场地的差别、含透镜体场地与不含透镜体场地对地震动影响的差别,以及透镜体埋深、宽度、厚度、刚度和输入波频谱等因素对地震动反应谱的影响.研究表明,层状场地与其等效的均匀场地有着显著的差别;透镜体的存在对地震动有显著的放大作用,该放大作用可达93.5%;由于入射波在透镜体周围的散射,会产生竖向加速度,且竖向加速度的短周期成分相对较多;透镜体埋深、宽度、厚度、刚度以及输入波频谱等因素对地震动反应谱具有重要的影响.     

克希霍夫法VSP多波联合成像

VSP 转换波跟VSP 纵波或常规地面转换波相比,具有较高的分辨率和信噪比,但传统的VSP成像方法只利用了反射P波信息,而把转换波（反射S波、透射S波）以及透射P波当作影响成像质量的噪音.本文给出了一种VSP共炮点道集多分量地震资料克希霍夫法偏移成像的方法.本方法充分利用了多波（反射P波、反射S波、透射P波、透射S波）信息,根据转换点处四种波同时起跳,能量叠加最大的原理,从接收点分别用向绕射点延拓它们的能量,并将其叠加起来,求得的和最大的一点即反射点.通过模型试算和实际资料处理表明,此法成像精度高,信噪比高,且有利于改善剖面的频率特性.     

数据挖掘技术在石油天然气勘探领域的应用探索

基于数据挖掘的概念,详细地阐述了岩石物理数据、测井数据、地震数据和地质数据的特征,并根据其数据特征,确定了岩石物理和测井数据、地震数据和地质数据的三种挖掘思路.用不同的挖掘思路对相应的数据分别展开挖掘,并从挖掘功能的角度分别描述挖掘的成果,即岩石物理数据之间的联系和对储层的预测;测井数据在复杂地质条件下对模糊储层的评价,及有效储层的识别;三维地震数据的空间挖掘成果;地质数据的图表和文本挖掘成果.数据挖掘技术将数据分析方法和对应的数学模型引入勘探领域,从海量的勘探数据中获取潜在信息,用于指导油气的勘探,实现了由数据指导勘探的目的,提出了数据勘探的概念.     

Modelling the hydrodynamics of offshore sandbanks

This paper describes the details of a quasi-three-dimensional model (3DBANK), which has been developed to investigate medium and long-term morphological evolution and development of offshore sandbanks. The model is based on a three-dimensional tidal module using the Galerkin-eigenfunction method, but also includes four sub-modules to compute: the instantaneous bedform characteristics from which the temporal and spatial variations of the shear stresses at the sea bed can be derived; the suspended sediment concentration through the water column; the bed-load and suspended sediment fluxes at a point-in-plan; and the resulting morphological changes, respectively. The model also includes the effects of the wind and waves at the sea surface, as well as the wave–current interaction (WCI), and operates with full hydrodynamic and morphodynamic interaction. The components of the model were tested against laboratory and field data, and the complete model was then applied to Middlekerke Bank off the Flemish coast where extensive field measurements were taken during the European Community (EC) funded Circulation and Sediment Transport Around Banks (CSTAB) Project using various advanced instrumentation including STABLE and HF OSCR. Comparisons of the model results with the field measurements and observations show that the model is capable of reproducing the current and wave-induced bedforms, bed roughness, tidal currents and tidal residuals around the sandbank satisfactorily, and can be used to study the long-term sandbank evolution under various offshore conditions. This paper, however, focuses on the hydrodynamic aspects of the model, while the details of the morphological components will be given in a companion paper.     

正断层黏滑错动作用下隧道抗错断技术模型试验研究

为提高穿越黏滑断层隧道的结构安全性和稳定性,开展了正断层黏滑错动作用下隧道抗错断措施作用效果室内模型试验。通过分析结构纵向应变、接触压力及安全系数,对未采取措施、结构加强、结构加强并施设减错层、结构加强并施设减错缝、结构加强并施设减错层和减错缝5种工况进行了对比分析。研究结果表明:采用减错措施（减错层/缝或减错层+减错缝）后,沿隧道纵向结构纵向应变、接触压力增加倍数由剧烈变化变为较均匀变化;仅采用结构加强措施抵抗正断层黏滑错动对隧道结构的影响,效果有限;通过采用减错措施消减正断层黏滑错动对隧道结构的影响,效果明显,结构安全系数最小值增加8倍以上;通过采用结构加强并施设减错层和减错缝措施抵抗和消减正断层黏滑错动对隧道结构的影响,效果显著,结构安全系数最小值增加25.45倍。研究成果可为高烈度艰险山区黏滑正断层隧道的抗错断设防设计提供参考。     

探测与2014年新疆于田MS7.3地震相关的大气CO和O3异常变化

基于AQUA AIRS传感器提取了2014年2月12日新疆于田M_S7.3地震前后CO和O₃数据, 讨论了数据变化与地震活动的关系。 差值法和异常指数法结果表明, 于田地震后CO和O₃在3月份达到最大异常, 且气体柱浓度异常沿NE向发震构造呈线性分布; 不同高度的CO和O₃的VMR值变化与差值法和异常指数法得到的结果相吻合; 地震前后短时间内CO和O₃气体柱浓度出现下降, 且地震当月最低。 初步推断可能是阿尔金断裂尾部在SW向运动过程中使得震区断裂带在弹性挤压状态下出现闭锁, 气体不流通导致; CO和O₃异常更多的可能是由于田地震引起地下气体大量释放, 其次可能是与地下气体逸散在大气圈中发生的一系列化学反应有关。 研究表明, 卫星高光谱遥感数据获得的CO和O₃的地球化学信息与地震有密切联系, 在地震监测及预测领域具有重要的应用价值。     

THEORETICAL APPROACH TO THE SOLUTION OF THE INFILTRATION PROBLEM

ABSTRACT

The one-dimensional transient downward entry of water in unsaturated soils is investigated theoretically. The mathematical equation describing the infiltration process is derived by combining Darcy's dynamic equation of motion with the continuity and thermodynamic state equations adjusted for the unsaturated flow conditions. The resulting equation together with the corresponding initial and boundary conditions constitues a mathematical initial boundary value problem requiring the solution of a nonlinear partial differential equation of the parabolic type. The volumetric water content is taken as the dependent variable and the time and the position along the vertical direction are taken as the independent variables. The governing equation is of such nature that a solution exists for t > 0 and is uniquely determined if two relationships are defined, together with the specified state of the system, at the initial time t = 0 and at the two boundaries. The two required relations are those of pressure versus permeability and pressure versus volumetric water content.

Since the partial differential equation has strong non-linear terms, a discrete solution is obtained by approximating the derivatives with finite-differences at discrete mesh points in the solution domain and integrated for the corresponding initial and boundary conditions. The use of an implicit difference scheme is employed in order to generate a system of simultaneous non-linear equations that has to be solved for each time increment. For n mesh points the two boundary conditions provide two equations and the repetition of the recurrence formula provides n—2 equations, the total being n equations for each time increment. The solution of the system is obtained by matrix inversion and particularly with a back-substitution technique. The FORTRAN statements used for obtaining the solution with an electronic digital computer (IBM 704) are presented together with the input data.

Analysis of the errors involved in the numerical solution is made and the stability and convergence of the solution of the approximate difference equation to that of the differential equation is investigated. The method applied is that of making a Fourier series expansion of a whole line of errors and then following the progress of the general term of the series expansion and also the behavior of each constituent harmonic. The errors (forming a continuous function of points in an abstract Banach space) are represented by vectors with the Fourier coefficients constituting a second Banach space. The amplification factor of the difference equation is shown to be always less than unity which guarantees the stability of the employed implicit recurrence scheme.

Experiments conducted on a vertical column packed uniformly with very fine sand, show a satisfactory agreement between the theoretically and experimentally obtained values. Many experimental results are shown in an attempt to explain the infiltration phenomenon with emphasis on the shape and movement of the wet front, and the effects of the degree of compaction, initial water content and deaired water on the infiltration rate.     

离心模型砂雨法制备技术研究与展望

砂雨法是开展砂质土层和构筑物离心试验应用广泛的模型制备技术,以密实程度与均匀性为关键控制对象,直接关系试验结果的准确性和可靠性。针对砂雨装置、控制要素和均匀度测试等几个方面,概况总结了国内外离心模型砂雨法制备技术的研究进展与暴露的关键问题,归纳了现有砂雨装置的基本组成、操控特点和分类方法,阐述了稳态密实度范围及影响关键因素。综述模型空间均匀度的不同量测与评价方法,评述了各自优缺点与归一化评价标准。综合现状与不足,讨论了离心模型砂雨法制备技术的发展方向与趋势。