化学波在对流介质中的折射与反射

以含有对流项的二维布鲁塞尔子为模型,导出化学波的波速随介质对流速度变化的关系式,用之说明化学波在对流介质中的折射与反射规律.结果表明:在对流介质中,尽管化学波在两种介质分界面上的折射与回折射(反射)仍然遵从波矢量切向分量连续定律,但折射角和反射角随入射角变化的规律与在静止介质中有所不同.当平面化学波从低速介质射向高速介质时,若介质对流速度方向与化学波的入射方向一致,在入射角大于临界角时,化学波在两种介质的边界上发生反常折射和反射现象,反常折射角随入射角的增大而增大,反射角随入射角变化,而且小于临界角;当平面化学波从高速介质射向低速介质时,若介质对流速度方向与化学波的入射方向一致,化学波在两种介质的边界上发生折射现象,折射角随入射角变化,先增大后减小.数值模拟结果进一步验证了理论结果.     

晶体偏光分束棱镜的光强透射特性理论研究

wollaston是一种重要的偏光分束器件,充分考虑了wollaston棱镜的,胶合层上下两种介质的折射率不同对光强透射比的影响,精确的分析了两束光的光强透射比随入射角,结构角和波长的变化关系曲线,结果表明：当胶合层是空气层时,平行于主截面的分量和垂直于主截面的分量都随参量的变化作周期性的变化,一般垂直分量的光强透射比比平行分量的光强透射比要大,而且垂直分量的光强透射比比平行分量的变化幅度要小得多。对特定的棱镜,可以通过调节入射角,在一定程度上可以调节两束光的光强透射比。     

非均匀介质薄膜反射率的角度依赖特性

基于半无限分层介质模型,讨论了具有一定折射率分布的非均匀介质薄膜反射率对入射光的角度依赖关系,得出了其光强反射率公式.在此基础上,通过数值模拟给出不同参数下非均匀介质薄膜的反射率随入射角的变化曲线.分析表明,反射率随入射角的增加呈现出先减小后增大的变化趋势.布儒斯特角随表面折射率、底层折射率、有效深度的增加及膜层厚度减小而增加,随入射波长的变化可以忽略.对于同一入射角,薄膜反射率随薄膜分层厚度增加以及表面折射率、底层折射率和有效深度的减小而减小.     

NiFe2O4铁氧体薄膜溅射产额的蒙特卡罗模拟

通过蒙特卡罗方法,运用SRIM程序,模拟了Ar+轰击NiFe2O4铁氧体靶材的过程,研究了不同入射能量及角度Ar+轰击NiFe2O4靶材引起的溅射产额。结果表明:离子垂直入射时NiFe2O4中各元素的溅射产额和出射原子能量都随入射离子能量的增大而增大;各元素产额的比率在低能离子入射时,变化较大,但能在较大的入射离子能量范围内保持相对稳定的值;离子斜入射时,随着入射离子角度增加,各元素的溅射产额先增大,后减小,并在77°左右达到最大值;离子入射角度变化时,并不严重影响各元素之间产额的比率,且组分比率能在较大的离子入射角度范围内保持相对稳定的值。     

地震动入射角度对盆地地震响应的影响

为了研究不同入射角度地震动作用下盆地地表地震响应,基于ABAQUS软件显式有限元计算平台,针对某一45°坡角的盆地,以狄拉克脉冲作为输入SV波,探讨了地震波倾斜入射角度改变时盆地地表峰值位移(PGD)等的变化特征.结果表明:入射波作用角度由0°,5°,10°,15°,20°,25°,30°依次增加时,盆地地表PGD表现出先增大后减小的趋势;当入射角度为10°时,地表PGD达到最大值,为输入地震波位移幅值的7.69倍,说明若按垂直入射进行地震响应分析所得结果将偏于不安全;较垂直入射情形,地震波倾斜入射时盆地表现出更为显著的边缘效应,边缘PGD最大值约为盆地中心PGD的1.3倍;地震动响应聚焦区域会随入射角度的增大逐渐向盆地右侧偏移.     

SV波入射下衬砌尺寸对引水隧道动力响应的影响

采用波函数的Fourier-Bessel级数展开方法,得到了SV波入射时,大型引水隧道平面地震响应的解析解,并对建立的场地模型进行数值计算.计算结果表明:SV波入射时,引水隧道衬砌的径向动应力随隧道内径的增大而增大,径向动应力的最大值与隧道内径呈线性关系,SV波入射引起的引水隧道衬砌的切向动应力随隧道内径的增大而增大.当入射角小于临界角时,切向动应力受隧道内径变化的影响很大.此外,引水隧道衬砌的径向动应力随衬砌厚度的增大而增大,切向动应力则随衬砌厚度的增大而减小.     

偏振光源形貌对空气隙型检偏棱镜光强透射比的影响

探讨了单色线偏振光源的形状、尺寸和取向对检偏棱镜光强透射比的影响．由于检偏棱镜结构误差的存在，使得棱镜空气隙间光的干涉条件发生了改变，引起透射光强分布的变化，入射光束尺寸越大，光强透射比变化就越稳定，圆形光源入射时，光强透射比对空间入射角和入射点的变化比线光源稳定，偏振线光源入射时，光强透射比随其取向的不同敏感性不一样．     

考虑地震波斜入射下河谷地形的大跨桥梁动力反应研究

大跨度桥梁的地震动空间变化的非一致影响不可忽略,斜入射是引起这种空间变化的主要因素.研究了斜入射条件下自由场数值模拟方法,建立了考虑地震动空间非一致性的大跨度桥梁三维有限元分析模型,以某跨海连续刚构桥为背景,研究了考虑非一致地震动空间的大跨桥梁地震动力反应,分析桥梁的内力幅值和分布规律.研究了地震波输入、斜入射角、地基土剪切波速以及河谷地形等影响因素的变化对P波及SV波作用下连续刚构桥结构动力反应的影响规律.结果表明,河谷地形条件下,墩底内力的变形规律和平坦地形相比有一些差异.斜入射时河谷地形的剪力和轴力的非一致影响系数与平坦地形相差比较大,P波作用下,墩底剪力和纵桥向弯矩随着入射角的增大而增大,墩底轴力随着入射角的增大而减小,SV波入射时,河谷地形条件下的墩底剪力和纵桥向弯矩随着入射角的增大而减小,墩底轴力随着入射角的增大而增大.     

各向异性人工材料的电磁波吸收特性

利用传输矩阵法研究了含各向异性人工材料的一维结构的电磁波吸收特性,分析了入射波频率、极化方向、入射角以及材料厚度对电磁波吸收率的影响.结果表明,电磁波垂直入射到单层各向异性人工材料中,尽管s波和p波的吸收率极大值出现在不同的频率,但两种波的吸收率随层厚增大的变化规律一致.斜入射时,不管入射角如何变化,s波和p波的吸收率都随着层厚的增大而趋于定值,该极限值由入射角决定.改变入射波频率,当某一频率对应磁导率张量的矩阵元的实部为负值,对应极化波的吸收率随层厚的增大而趋于定值;当磁导率张量的矩阵元的实部为正值,对应极化波的吸收率随层厚的增大而振荡,且峰值出现在层厚为λ/2的整数倍时.含各向异性人工材料的三层结构的吸收率优于单层结构.以上结论可为使用各向异性人工材料制作电磁波吸收器提供理论支持.     

平面波斜入射时水中液体柱形粒子的声辐射力

利用声散射理论,推导了平面波斜入射时水中液体柱形粒子的声辐射力,研究了入射角变化对柱形粒子声辐射力的影响,并对水中不同液体柱形粒子的声辐射力进行了仿真。结果表明:在声波以小角度入射情况下,当ka值较小时,声辐射力几乎不随入射角变化;当ka2时,声辐射力随入射角的增加而减小。在入射角趋于纵波临界角情况下,不同材料粒子的声辐射力随ka的变化规律基本相同。     

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)

正~~     

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.     

Tracking data management using topology of moving object database system for moving object constrained trajectory in LBS application

Advances in wireless technologies and positioning technologies and spread of wireless devices, an interest in LBS (Location Based Service) is arising. To provide location based service, tracking data should have been stored in moving object database management system (called MODBMS) with proper policies and managed efficiently. So the methods which acquire the location information at regular time intervals then, store and manage have been studied. In this paper, we suggest tracking data management techniques using topology that is corresponding to the moving path of moving object. In our techniques, we update the MODBMS when moving object arrived at a street intersection or a curved road which is represented as the node in topology and predict the location at past and future with attribute of topology and linear function. In this technique, location data that are corresponding to the node in topology are stored, thus reduce the number of update and amount of data. Also in case predicting the location,because topology are used as well as existing location information, accuracy for prediction is increased than applying linear function or spline function.