用于双通道椭圆弯晶谱仪的天然云母实验

叙述了双通道椭圆弯晶谱仪的结构原理,详细阐述了天然云母弯晶分析器作为色散元件的制作过程．并在星光Ⅱ激光装置上对金平面靶进行了打靶实验,得到金平面靶的谱线图像数据．为了分析谱线图像数据相互混叠、相互交错的原因,对丹巴天然云母还进行了X射线单晶衍射实验与表面观察实验．实验结果表明,选择丹巴天然云母作为色散元件是造成谱线图像相互混叠、相互交错的根本原因．     

硬X光在线弯晶谱仪的设计与实现

该文介绍了具有定量化测量能力的硬X光在线弯晶谱仪,其主要结构为透射弯晶、Cs I(Tl)闪烁体薄膜、像增强器、可见光CCD,主要功能是定量获得较高能谱分辨的X光谱,由光谱获得超热电子温度和总能量的数据,为大尺度激光等离子体物理实验研究建立超热电子定量诊断的有效手段。该文对其主要光学结构及关键部件参数做了详细阐述。利用Ag靶准单色射线源作为测试源,对谱仪的性能进行测试,结果为Ag的特征谱线能清晰对称地呈现在记录结果中,谱线均匀无缺失,分辨效果较好,表明谱仪的性能良好。     

双通道椭圆弯晶谱仪分辨率的影响因素分析

双通道椭圆弯晶谱仪（以下简称TCECS）是激光惯性约束核聚变研究中非常重要的诊断仪器，通过在两个通道上同时进行X射线的空间和时间分辨测量，从而对惯性约束聚变的实验情况做出正确的判断。TCECS分辨率的影响因素较多，主要有椭圆的离心率、狭缝的宽度、光源没在椭圆的前焦点上、探测圆轴线没有通过椭圆后焦点，瞄准对中等引起的误差。本文分析了影响TCECS分辨率的主要因素，用Matlab6.1软件进行了数值计算，并提出了保证和提高TCECS分辨率的措施。     

用于激光等离子体X射线诊断的谱仪

为了诊断波长为0.5～0.8 nm的激光等离子体X射线,研制了一种新型的高空间和光谱分辨率的晶体谱仪.采用2个不同分光计材料、不同形状且相互垂直分布的通道可以同时获得谱线的空间和光谱分辨率.利用成像板接收光谱信号,其有效接收面积为30 mm×80 mm.讨论晶体基本参数和给出了谱仪设计参数.在中国工程物理研究院激光聚变研究中心的20 J激光器装置进行实验,两个方向的成像板同时获取得到了Al激光等离子体X射线光谱,其中水平通道的PET平面晶体获取的空间分辨率为1.73～6.88 mm,而垂直通道的Mica球面弯晶得到的光谱分辨率达到1 000～1 500.实验结果表明该谱仪适合于激光等离子体X射线的光谱学研究.     

球面弯晶分析器研制

在激光聚变实验中为了获取等离子体的重要信息,采用球面弯曲晶体成像谱仪来研究等离子体辐射的X射线,利用球面弯晶对X射线进行诊断而提供时间、空间、光谱分辨。该强聚焦晶体能增强信噪比,提高谱仪的空间分辨能力及立体角收集辐射能力。实验结果表明球面弯晶分析器对波长范围为0.2~0.4 nm的X射线其分辨率可达600~1 000,聚光效率在同样距离条件下比平晶分析器高一个数量级以上,适合于研究等离子体X射线光谱学。     

整体平行束X光透镜在实验室EXAFS谱仪中的应用研究

结合整体平行束X光透镜在实验室EXAFS谱仪中应用研究,利用整体平行束X光透镜和粉末衍射仪设计了一种实验室EXAFS谱仪.工作电压和电流分别为25 kV和100 mA时,该谱仪在9.92 keV能量点处,计数率为3.12×104 s-1,在钨杂质的特征谱线Lβ1能量点处,能量分辨率为15.4 eV.整体平行束X光透镜在该谱仪中既起到会聚X射线的作用又可实现高能滤波器的功能.对实验现象进行了理论分析.     

等电子谱线法诊断等离子体电子温度实验研究

在"星光Ⅱ”激光装置上对Mg/Al混合材料平面靶和Mg/Al示踪层金盘靶进行三倍频激光打靶实验,用平面晶体谱仪测量靶材料发射的X光光谱,获取了示踪离子谱线实验数据.采用多组态Dirac-Fock方法计算所需原子参数,并在局域热动平衡条件下建立了双示踪离子谱线强度比随电子温度变化关系.在此基础上由双示踪元素等电子谱线法确定了Mg/Al混合材料平面靶及金盘靶激光等离子体的电子温度.     

使用X光透镜和位置灵敏正比计数器的高能量分辨微束XRF谱仪

报导一种新型微束X荧光分析谱仪,它由导管X光透镜和使用位置灵敏正比计数管的波长色散谱仪组成.谱仪具有高空间分辨,高能量分辨和高灵敏度的特点.从实验上研究了影响谱仪能量分辨的各种因素及用于稀土元素L线分析的可能性.实验结果表明谱仪使用X光透镜形成的X光微束的最小束径对Mo-Kα线为30μm,谱仪对Ti-Kα线的能量分辨为4.4 eV,对稀土元素L线的最低探测极限达到10-10g.     

弯晶的引出效率与同步加速器的束流动力学稳定性

近年来,弯晶的束流控制技术得到了迅速发展．在加速器物理中,粒子能量和束流强度一直是人们追求的目标,而引出技术和引出效率则是保证柬流强度的关键．在经典力学框架内和偶极近似下,导出了粒子在弯晶中的一般运动方程．在准静态近似下,利用哈密顿原理分析了系统的稳定性;在相空间密度均匀分布假设下,利用相面积概念讨论了弯晶的引出效率．用Melnikov方法描述了系统的混沌行为及临界性质,给出了常曲率和变曲率弯晶的退道长度．     

质子交换中苯醌自由基CIDEP谱的变化

本文用时间分辨ＥＳＲ波谱仪，研究了对苯醌／乙二醇／水体系中光解苯醌自由基的质子交换。观察了ＴＲＥＳＲ谱的线形与溶液的ｐＨ值关系．在溶液为中性时，谱线为ＢＱＨ·的六条发射线，当ｐＨ～２．０２时谱线为ＢＱＨ２＋的五条发射线．ＢＱＨ２＋的各超精细分量的衰减速率与因交换而移动的谱线所占份额有关，那些因交换而移动的线所占的份额越大，谱线强度的衰减越慢     

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).     

Wuhan University Journal of Natural Sciences TOTAL CONTENTS

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