多分量瑞利波勘探研究

提出多分量瑞利波勘探技术的新思路，分析了噪声对相速度测量精度的影响，建立了用极化滤波提取有效瑞利波信号的方法。处理及分析表明：多分量瑞利波勘探与单分量法比较，勘探的可靠性有所提高。     

基于τ—p变换的频散曲线及其算法实现

论述了瞬态瑞利波勘探的原理及频散曲线在勘探中的重要性,在分析采集数据时的注意事项和影响τ－ｐ变换的几种因素的基础上,结合实例探讨了用τ－ｐ变换法求瞬态瑞利波频散曲线的方法,并给出了该方法的流程图及其分析结果。     

瑞利波泄漏模式的模拟研究

瑞利导波相速度频散曲线有时会出现截止或截断现象,此时必须考虑泄漏模式波的存在,如何快速求取泄漏模式波的相速度大小是研究的核心问题．采用添加附加层的方法,使瑞利波实频散方程求根的范围包含所有的层速度区域,从而可用Abo—zena,Menke和Bixing Zhang等学者研究过的传递矩阵理论,利用二分法求解相速度大小,即用导波来模拟计算泄漏模式波相速度大小．从模拟计算结果来看,附加层法不仅能模拟出原模型的实数导波,而且还能计算出泄漏模式波的变化．由此可见,用附加层法来计算瑞利波的泄漏模式是可行的;同时,若将该方法应用于瑞利波勘探的反演,它不会增加未知数的个数。     

瞬态瑞利波法在秦峪滑坡勘查中的应用

秦峪滑坡是国道212线上最严重的滑坡之一,是在断裂带基础上发育的多层次、多期次大型滑坡群组合体.在探测覆盖层的厚度、基岩埋深、滑坡的滑动面等方面,瞬态瑞利波勘探是一种有效的地震勘探手段,为此利用瞬态瑞利波勘探方法对秦峪滑坡进行了勘探,基本查明了滑坡的剖面结构,为国道212线秦峪滑坡的治理以及拟建兰州一海口高速公路的选线和设计提供理论依据.     

岩石边坡失稳的瑞利面波频散响应特征

根据边坡失稳的地球物理模型,系统研究了岩石边坡失稳的瑞利面波基阶模的相速度、波数响应特征,总结了边坡从稳定→失稳演化过程的瑞利面波基阶模频散特征变化规律,从中提取边坡失稳的瑞利面波基阶模相速度、波数、频散曲线等特征标志,使瑞利面波法不仅能用于探测边坡失稳的滑动面或结构面,而且还能评价边坡的稳定性,对边坡失稳进行综合预测预报.     

瞬态瑞利波分析方法在探测地质体结构中的应用

介绍了探测地质体结构的一般方法,重点介绍了爆破地震波的特征及地震波的探测方法.又对最近发展起来的面波勘探技术做了分析,重点论述了瞬态瑞利波频散特性及其应用.在此基础上,实验了一种可以控制的爆破地震波震源,该震源利用水介质的均匀性及各向同性、不可压缩等特点,减少了爆炸冲击波对周围岩体介质的损坏,又保持了爆炸波功率大,能够提供尖锐的脉冲信号,频域范围大的特点,从而改变了爆破地震波震源不能重复和难以总结其规律的状况.利用瑞利波探测技术和可控爆源,对茅坪滑坡体进行了地质体结构探测,并对其地质体的分层特性做了详细分析,与钻孔勘探结果和挖竖井探测结果比较,二者有较好的一致性.说明结合瞬态瑞利波分析方法,该可控震源在地质体结构探测中有实际的应用价值.     

阻尼LSQR算法在多波地震反演中的应用

多波VTI介质AVA储层参数联合反演的关键是解Jacobi矩阵。本文从Lanczos迭代出发,结合双对角化和QR分解,推导出了阻尼Lanczos算法流程。通过比较SVD算法和LSQR算法,显示了阻尼Lanczos算法在效率和精度方面的优越性。该算法应用于多波地震勘探资料反演中,获得的目标层储层参数:纵波速度、横波速度和密度,证明了该算法的有效性。     

基于起伏地形的瑞利面波有限差分数值模拟

利用瑞利面波的频散特性及其不同频率瑞利面波能量随探测深度衰减变化规律,能够用来进行浅地表的地质勘探和地球内部构造的研究。利用有限差分数值求解的算法,模拟起伏条件下的地下介质中的瑞利面波;建立速度-应力弹性波动方程,利用交错网格的差分方式,引入完全匹配层(Perfectly matched layer,简称PML)的人工边界条件,对几种简单的起伏地表模型进行正演模拟。结果表明交错网格有限差分方法有比较好的精度,PML边界条件能够对来自边界的虚反射有较好的吸收处理。     

波动方程基准面在深层勘探中的应用

考虑到在波场延拓算子的成像效果，其运算效率及对复杂地表的适应情况或处理措施下，利用波场延拓算子将基准面下移，以提高深层复杂地质体的偏移成像效果．在集成基准面技术和登前深度偏移基础之上，提出了一种不受地表不规则程度和速度函数变化限制的基准面向下延拓方法．实践证明，该方法用于深层复杂地质体的勘探时，可以使偏移成像得到更好的效果，其运算速度与叠前深度偏移的运算速度相当．     

信号特征分析的一种新方法

信号特征分析是地球物理勘探中模式识别的关键，小波分析方法对局部信号进行分析优于付氏变换，将该方法用于声波测井和地震勘探的信号分解，在一系列频段上重新表示信号，突出其重要特征，从而为超声信号和地震信号特征分析提供一种实用方法，文中给出理论分析和分析实例。     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

海南岛地体及其毗邻陆缘晚中生代—新生代古地磁研究和构造演化

本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。     

Exciton Seebeck in Molecular Systems

Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with     

Achieving Unusual States of Matter Under High Pressure

The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to     

《Chinese Science Bulletin》SUBJECT INDEX TO VOLUME 59(2014)

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An on-line scaling method for improving scalability of a database cluster

The explosive growth of the Internet and database applications has driven database to be more scalable and available, and able to support on-line scaling without interrupting service. To support more client's queries without downtime and degrading the response time, more nodes have to be scaled up while the database is running. This paper presents the overview of scalable and available database that satisfies the above characteristics. And we propose a novel on-line scaling method. Our method improves the existing on-line scaling method for fast response time and higher throughputs. Our proposed method reduces unnecessary network use, i.e. , we decrease the number of data copy by reusing the backup data. Also, our on-line scaling operation can be processed parallel by selecting adequate nodes as new node. Our performance study shows that our method results in significant reduction in data copy time.     

An improved R-tree based on childnode''s probability

R-Tree is a good structure for spatial searching. But in this indexing structure,either the sequence of nodes in the same level or sequence of traveling these nodes when queries are made is random. Since the possibility that the object appears in different MBR which have the same parents node is different, if we make the subnode who has the most possibility be traveled first, the time cost will be decreased in most of the cases. In some case, the possibility of a point belong to a rectangle will shows direct proportion with the size of the rectangle. But this conclusion is based on an assumption that the objects are symmetrically distributing in the area and this assumption is not always coming into existence. Now we found a more direct parameter to scale the possibility and made a little change on the structure of R-tree, to increase the possibility of founding the satisfying answer in the front sub trees. We names this structure probability based arranged R-tree (PBAR-tree).     

Integrating GIS Web services based on mediating architecture

The geographic information service is enabled by the advancements in general Web service technology and the focused efforts of the OGC in defining XML-based Web GIS service. Based on these models, this paper addresses the issue of services chaining,the process of combining or pipelining results from several interoperable GIS Web Services to create a customized solution. This paper presents a mediated chaining architecture in which a specific service takes responsibility for performing the process that describes a service chain. We designed the Spatial Information Process Language (SIPL) for dynamic modeling and describing the service chain, also a prototype of the Spatial Information Process Execution Engine (SIPEE) is implemented for executing processes written in SIPL. Discussion of measures to improve the functionality and performance of such system will be included.