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本文探索了在预测臭氧含量演变趋势的一种分析方法,该方法将臭氧总量分为三到五个状态,并用状态间的转移频率近似地代替状态间的转移概率,预测其最大可能的变化方向,并给出了具体的应用实例。  相似文献   

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本文根据非线性科学观点,从多分形、自组织临界现象和浑沌动力学等三个方面综述了地震孕育过程的动力学演化特征及其系统的不稳定性问题。  相似文献   

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波前重建法折射成像及应用研究   总被引:2,自引:0,他引:2  
赵成斌 《地球物理学报》1999,42(Z1):188-194
根据实际工作需要对传统的地震折射资料解释方法的适用范围进行了讨论,指出了传统折射资料解释方法所存在的问题。采用重建波前的方法进行折射成像,通过改进震源函数,并在反演过程中使用有限差分技术解程函方程,进行波场外推,从根本上解决了传统折射资料解释方法存在的问题,计算精度高,速度快。通过理论模型和实际资料的对比计算和验证,效果良好。  相似文献   

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Dynamic elastic moduli like E, μ, K and μ of the foundation rock of a dam have been determined by finding Vp- and Vs-velocities by seismic refraction with a hammer as source. Some parameters such as “fracture frequency” and “rock quality designation” (RQD) of the foundation rock have been derived using “average regression curves” and Vp-velocities. By comparing K/μ with Vp/Vs, a few locations showing weathered conditions have been demarcated. This compares well with RQD values of those locations.  相似文献   

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地震折射波法在郑州市西区浅层勘探中的应用   总被引:1,自引:0,他引:1       下载免费PDF全文
在城市活断层勘探中,对于面波干扰大、地震反射波法难以开展工作的区域,可尝试利用地震折射波法进行探测,并对折射波法探测的原始记录采用时间项、差异时距曲线和有限差分成像等方法进行综合计算、分析,以探索折射波法在城市活断层勘探中的应用成效。文中针对郑州市须水断层西段浅层地震折射波法勘探记录,利用时间项、差异时距曲线和有限差分成像等计算方法,获取剖面速度结构与界面构造;综合震相特征、计算结果等资料确定主要地层的界面深度和构造特征,3种方法都取得了相近的结论。后又通过在测线上4个钻孔资料的验证,认为3种方法的计算结果与钻孔资料相吻合,说明折射波法勘探在城市活断层探测中的应用是可行的  相似文献   

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开鲁陆家堡凹陷内断裂发育、构造复杂,垂直于构造走向跨度30km,凹陷边缘和凹陷内古生界基底顶板埋深分别为1km和5km,在此开展了基底折射波地震勘探。在已知资料基础上,我们用多段倾斜单界面折射波正演理论计算作指导,设计了野外试验和初步的生产观测系统,t_0和差异时距曲线解释方法对于应用于如此复杂的构造地区其准确性和精度受到了限制。因此,我们在解释方法上试做了如下工作:①多段倾斜单界面折射波理论正演走时拟合,给出较有益的反演解释结果;②二维非均匀介质中射线追踪解释方法,提供准确的射线途径给出基底面上下详尽的更为符合实际的二维速度分布信息。  相似文献   

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本给出了一种矩形有疬钢筋混凝土蓄水池的震害预测方法和计算分析程序,并对两蓄水池进行了震害预测分析,得出震害经验相符合的结论-地下式水池比地上水池的抗震能力强,从而证明了本方法的实用性。  相似文献   

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古城西安,以其名胜古迹、艺术珍藏之丰硕著称于世。为了开发我国古代的灿烂文化,在陕西省文物管理局组织下,几个单位分别用多种方法对一座位于西安曲江池的汉代古墓进行了非破坏性探测试验。这里,简介西安地质学院应用浅层地震方法探测古墓的试验情况。  相似文献   

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古城西安,以其名胜古迹、艺术珍藏之丰硕著称于世。为了开发我国古代的灿烂文化,在陕西省文物管理局组织下,几个单位分别用多种方法对一座位于西安曲江池的汉代古墓进行了非破坏性探测试验。这里,简介西安地质学院应用浅层地震方法探测古墓的试验情况。  相似文献   

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孙传文  王光锷 《地震地质》1992,14(2):176-182
通过反演受近地表不均匀介质影响的大地电磁测深资料的新方法,可获得较准确的一维地电断面参数、不均匀体埋藏深度及其电性特征。本方法计算速度快,单测ρxy,ρyx可独立反演并相互验证结果的准确性  相似文献   

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用慢度分块均匀正方形模型将介质参数化,仅在正方形单元的边界上设置计算结点,这些结点构成界面网.根据Huvsens和Fermat原理,由不断扩张、收缩的波前点扫描代替波前面搜索,在波前点附近点的局部最小走时计算中对波前点之间的走时使用双曲线近似,通过比较确定最小走时和相应的次级源位置,记录在以界面网点位置为指针的3个一维数组中.借助这些数组通过向源搜索可计算任意点(包括界面网以外的点)上的全局最小走时和射线路径.这一方法不受介质慢度差异大小限制,占内存少,计算速度较快,适于走时反演和以Maslov射线理论为基础的波场计算.  相似文献   

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计算最小走时和射线路径的界面网全局方法   总被引:27,自引:16,他引:27       下载免费PDF全文
用慢度分块均匀正方形模型将介质参数化,仅在正方形单元的边界上设置计算结点,这些结点构成界面网.根据Huvsens和Fermat原理,由不断扩张、收缩的波前点扫描代替波前面搜索,在波前点附近点的局部最小走时计算中对波前点之间的走时使用双曲线近似,通过比较确定最小走时和相应的次级源位置,记录在以界面网点位置为指针的3个一维数组中.借助这些数组通过向源搜索可计算任意点(包括界面网以外的点)上的全局最小走时和射线路径.这一方法不受介质慢度差异大小限制,占内存少,计算速度较快,适于走时反演和以Maslov射线理论为基础的波场计算.  相似文献   

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地震烈度衰减关系统计方法的探讨   总被引:2,自引:0,他引:2  
在地震学和地震工程学的研究中,地震烈度衰减关系的研究和应用日益受到重视。本文从在等烈度外包线上如何取烈度值,烈度衰减曲线的头尾处理,R0值的选取,衰减公式的偏差这四个方面对目前广泛使用的地震烈度衰减关系的统计方法作了分析和探讨,指出了这些方法中存在的不足,并提出了改进的建议。  相似文献   

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本文利用最近的海上石油物探资料,从地质构造等方面论证1918年南沃大震的震中位置,并用历史水位及宏观资料推断了本次地震的震源机制解,讨论了震级问题,余震序列特征,估算了强余震震级的方法和预测强余震发生的时间问题,由于震级参数的重新论证,对泉州—汕头地震带地震活动性应作重新估计。上述问题的讨论对指导今后该区的地震监视预报均有一定的参考价值。  相似文献   

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A method for pseudoreflection profiling (PRP) is presented. By using transmission seismograms, this method produces time sections similar to those obtained using the common depth point (CDP) method. Pseudoreflection profiles are obtained using the following procedure. Equivalent transmission responses at sites on soft deposits are derived by Wiener filter estimation using seismograms acquired on the sites and on the basement rock. These responses are substituted into the Claerbout-Kunetz equation to obtain the pseudoreflection profiles. A 3D subsurface model is produced when the PRP method is applied to explosion seismograms. The time sections thus obtained are consistent with those obtained using the CDP method in a neighbouring area. The maximum station interval for obtaining coherent profiles with this method is estimated to be one quarter of the wavelength of the transmitted waves. This technique should be used in combination with another method such as the CDP method because it has two weak points: the velocity structure cannot be obtained directly and undesirable waves cannot be eliminated through processing.  相似文献   

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Complete analytical expressions are developed for the first and second derivatives of the Newtonian gravitational potential in arbitrary directions due to the homogeneous revolutional compartment with a polygonal vertical section by applying the Gaussian divergence theorem in the cylindrical coordinate system. Elementary solutions presented can easily be translated into magnetic anomalies caused by a uniformly magnetized body. The divergence approach in the polar coordinate system is also described, and gravity attractions in the radial direction are presented in closed form associated with a homogeneous cap compartment. The explicit solutions are tested against well-known formulae for a cylinder, cone, infinite plate, and sphere.  相似文献   

18.
The combined observation of first and later arrivals in shallow seismic refraction surveys, particularly on hard rock terrains, is discussed. Details of experimental weathered-zone investigations by the correlation refraction method in a granite terrain (i.e. field procedure, seismograms obtained, plotting of the data, and identification of the waves are presented). Complete travel time data and interpreted subsurface sections of a few test refraction surveys are included. In one instance the interpreted results of normal and converted refracted wave data have been tested by drilling at three points along a 220 m long profile.  相似文献   

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The quantification and prediction of damage due to different seismic actions to structure types of different strength is an important problem not yet solved in the Earthquake Engineering field. In addition, owing to the fact that macroseismic information cannot be used directly in dynamic calculations, a new problem appears when these are the only kind of data available. Thus, there is a need to estimate a parameter to relate the energy of the ground motion and the damage occurrence, and eventually achieve a better seismic risk assessment. After the study and review of some representative potential damage parameters, attention has been paid to the Arias intensity (unfiltered and filtered in certain frequency ranges) and the Cumulative Absolute velocity (CAV) as the parameters to evaluate the energy of movement, and to relate them with the observed damage. The data used to infer these correlations have been provided by the ENEA-ENEL (Italy). The information consists of strong motion records from the Campano Lucano (1980), Umbria (1984) and Lazio-Abruzzo (1984) earthquakes, and data of damage to buildings in the vicinity of recording instruments (within a maximum radius of 300 m, where the soil conditions remain constant). In this paper, some relations have been obtained to quantify the damage level for different seismic inputs. The results suggest that unfiltered Arias intensity and CAV (for calculation threshold 20 cm/s2) correlate well with the macroseismic information used. Best fits are obtained between the quoted parameters and the observed damage in type A structures. © 1997 by John Wiley & Sons, Ltd.  相似文献   

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