铁磁颗粒膜的自旋激发色散关系研究

应用颗粒膜中颗粒自旋波激发和自旋极化激发的色散关系表达式，对Fe-SiO2颗粒膜进行了计算，探讨其色散规律,结果表明：颗粒自旋波激发与温度无关，而自旋极化激发与温度有关，两者的波谱都随波矢增大而增大，且波矢取分离值，不具有块状晶体自旋波色散关系周期性的变化特征．     

色散介质中脉冲传播的矩阵方法

通过变量代换,将描述光脉冲在二阶色散介质中传播的时间效应方程,化为与描述光波在一个横方向衍射效应的近轴波方程同样的形式后,借助于描述近轴光学行为的矩阵方法,对啁啾光脉冲在色介质中传播的时间行为进行了研究,并对引入的“时间光线”和“时间透镜”等概念进行了物理阐释。     

外界场作用下激发介质的波前曲率关系

通过波前曲面上的移动坐标系和波前边界层的摄动分析，得到波前曲面的法向速度与波前曲率、外界场之间的线性关系，即场作用下的Eikonal方程。此关系的物理意义解释了激发介质螺旋波、回卷波在外界场作用下的Belousov—Zhabotinsky实验现象；几何意义给出一个确定波前边界形状的理论方法。     

压电晶片激发理想流体中各向异性板的泄漏Lamb波

基于流固耦合理论,采用有限元方法,建立压电激发理想流体中各向异性板的泄漏Lamb波的数值模型.数值模拟研究单向纤维增强复合材料中的泄漏Lamb波的色散和衰减特征,得到了全波场数值解,进而分析了不同激励频率,不同纤维取向对波形的影响.结果表明:理想流体中各向异性板的泄漏Lamb波可存在非色散,衰减较小的So模态和色散,衰减较大的Ao模态;通过选择激励频率可以选择合适的传播模态.材料纤维取向不同会影响泄漏波形的传播速度以及色散和衰减特性.数值模拟建立了激励源、材料参数以及相应波形之间的定量关系,可为泄漏Lamb波技术应用于NDE和NDT提供理论参考.     

位置扰动对激发介质中螺旋波动力学行为的影响

本文在Greenberg-Hastings激发介质元胞自动机模型规则网格基础上施加位置扰动,以此模拟激发介质中激发元之间相互作用距离的改变。计算机数值模拟结果表明:对于在规则网格下产生的稳定螺旋波,施加位置扰动后发现,螺旋波斑图的稳定性与元胞位置扰动的幅度有关,不同幅度的元胞位置扰动导致稳定螺旋波发生两种不同的变化:漫游后形成新的稳定螺旋波;漫游后从系统中消失。通过波头运动轨迹和系统激发比率的变化来简要分析产生这些现象的原因。     

阶跃型单模石英光纤中受激喇曼散射的模式分析

在以YAG倍频激光器为光源进行阶跃型单模订英光纤的受激喇曼散射实验中发现，随斯托克斯波级次的增高，产生的模式为光纤所能传输的最高阶模式。由于光纤中介质对不同的波长具有不同的色散效应，因此，要求形成导模的斯托克斯波能同时满足色散效应和受激喇曼位相匹配这两个条件，才能在光纤中传输．根据理论计算能够很好的解释实验现象。     

一列非线性回归模型的非线性度量

考虑一列非线性回归模型 ,利用Bate和Watt的理论得到了其固有曲率和参数效应曲率 ,分析了参数效应曲率的弊端 ,指出其与许多模拟研究结果不吻合 ,利用待估参数与迭代初始值之间的函数关系及其微商运算构造了一种新的非线性度量方法 ,它不再具有参数效应曲率的蔽端 ,并在其它正常情况与Bate和Watt的理论相吻合 ,最后对Fieller -Creasy模型作了较为详细的研究 .     

三角海森堡反铁磁体中的磁激发

利用标准的自旋波理论，研究了二维三角海森堡反铁磁体的色散关系．分别采用了三子格模型和单子格模型来描述同一平面上几何阻挫的三角反铁磁结构，并对两者的结果进行了比较和分析．研究表明无论是基于三子格模型还是基于单子格模型，磁激发展示了一致的机制，色散关系也完全相同．单子格模型的研究为以后计算三维六角密排晶格的磁激发提供了简便的方法．     

ω≈ωce区域内电子回旋波色散关系的非相对论研究

给出了非相对论情况下,电子回旋波热等离子体色散关系在ω≈ωce时的表达形式,并在非相对论的适用条件下取代热等离子体色散关系与冷等离子体色散关系进行了对比,计算了寻常波(O波)和非寻常波(X波)的波迹,结果表明,两种模型得出的结果差别很小。     

三维各向异性介质中弹性波方程交错网格高阶有限差分法数值模拟

三维数值模拟是研究各向异性介质中复杂弹性波波场特征和传播规律的重要手段。根据Taylor展开式,推导出了交错网格一阶空间导数的任意偶数阶精度有限差分近似式和相应的差分系数计算式,给出了三维各向异性介质中弹性波一阶双曲型应力速度方程交错网格任意偶数阶精度差分格式和稳定性条件,并推导出了三维各向异性介质PML法吸收层边界条件公式和相应的交错网格差分格式。对方位各向异性介质模型和正交各向异性介质模型中弹性波的传播进行的三维数值模拟结果表明,弹性波在三维各向异性介质中传播时存在拟P波、拟SV波和拟SH波,并出现横波分裂、横波分裂盲区、波面三分叉等特殊现象,另外,弹性波场在空间是变化的,其拟P波、拟SV波和拟SH波的耦合关系比较复杂。     

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.     

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).     

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.     

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.