活性反应蒸发制备氢化非晶硅的稳态光电导和复合过程

本文报告了用掺杂和轻度磷掺杂的活性反应蒸发,制备氢化作品硅的稳态光电导对温度及光强的依赖特性.在研究的样品中复合率由复合中心的陷获空穴对自由电子的俘获过程所限制,掺杂改变了定域态分布的形状,因而改变了光电导与光强关系的指数ν.掺杂也改变了费米能(?)的定域态密度,轻度的磷掺杂可以使光电导增大,,当磷掺杂使费米能级与导带扩展态距离小于0.25eV 时光电导反而变小.     

GD-a-SiC∶H薄膜光诱导电导变化

本文主要介绍了 GD—a—SiC∶H 薄膜长时间光照前后暗电导、光电导、缴活能的变化,并介绍了光照前后光电流与光强的关系.实验表明这种变化与样品的费米能级位置有关,电导激活能小的样品呈现正常的 S—W 效应.电导激活能大的样品呈现反常的 S—W 效应。     

高速沉积的α—Si:H薄膜光致变化的光电导研究

本文研究了高速生长的氢化非晶硅合金(a—Si:H)的光致亚稳变化,即 Stabler-Wrondki(S.W)效应.做了退火态(A 态)和长时间光照后的光浸态(B 态)的光电导温度曲线的测量,并利用一个较合理的缺陷态分布模型对其进行了模拟,从而发现长时间光照的主要结果是引起带隙中悬挂键的增加,带尾态的变化不明显,另外对光电导与光强的关系中的γ因子进行了计算和讨论.     

退火对非晶态碲镉汞薄膜稳定态光电导的影响

利用射频磁控溅射方法,在宝石衬底上制备了非晶态碲镉汞(a-HgCdTe)薄膜。对原生a-HgCdTe薄膜进行了不同退火时间和不同退火温度的热退火,在80～300K温度范围内,分别测量了原生和退火处理后的a-HgCdTe薄膜样品的稳定态光电导,研究了退火时间和退火温度对非晶态HgCdTe薄膜的稳定态光电导和激活能的影响。结果表明,原生和退火a-HgCdTe薄膜的稳定态光电导具有热激活特性;随着退火时间增加或退火温度升高,a-HgCdTe薄膜的晶化程度提高,导致光电导增大,光电导激活能降低。利用非晶-多晶转变机制讨论了实验结果。     

氢化非晶硅光电导研究中的新现象

研究了衬底温度（Ｔｓ）从室温至６２３Ｋ生长的氢化非晶硅（ａ—Ｓｉ：Ｈ）的光电导的温度依赖关系，首次发现了出现光电导的热淬灭（ＴＱ）的温度区随ａ—Ｓｉ：Ｈ的Ｔｓ的降低系统地移向较低温度区．分析了ａ—Ｓｉ：Ｈ中这种新现象与费米能级位置以及能隙中缺陷态密度分布的关系．     

高频溅射α-Si:F,H薄膜光电导的实验与计算

通过对射频溅射RF a-Si:F,H薄膜样品光电导随入射光的波长、光强以及温度变化的测量,定量地考察了带隙、带尾态的宽度和带隙中悬键态密度与氟含量的关系,给出了氟原子在网络中一种可能的分布形式。按照Rose模型,计算了电光导随温度的变化关系,给出了局域态分布的位置、高度、宽度以及俘获截面等参量,理论计算与实验符合较好。     

a-Si:H的光电导衰退与微结构的关系

目前,主要流行的两类微观机制模型——“负有效相关能模型”和“断键模型”——都表明a-Si:H的光诱导变化与其微观结构有关.本文研究了不同制备工艺条件对a-Si:H微结构的影响,和样品的光电导衰退依赖于微结构的关系.最后,从S—W效应的微观机制作了简短讨论.     

非晶态硒化镉薄膜光电特性的研究

本文报道用真空热蒸发淀积非晶态硒化镉薄膜,研究淀积基底温度及退火处理对薄膜光电特性的影响。光谱实验表明吸收边有随基底温度降低而向长波方向移动的现象,发现淀积基底温度为150℃的样品其光电导与暗电导的比率最高。用超短序列光脉冲对薄膜的瞬态光电导特性进行研究,表明非晶态硒化镉薄膜对ps级超短光脉冲具有良好的瞬态响应,可用作快速光电探测器的光敏材料薄膜。     

非晶态硅氟合金光电导特性的研究

本文报道了对射频溅射α—Si:F薄膜光电导特性初步研究的结果。含氢和不含氢的样品是在Ar SiF_4和Ar SiF_4 H_2两种混合气体中分别制备的。对所有制得的样品测量了室温暗电导和在λ=6328及光照射样品表面功率密度为0.5mW/cm~2条件下测量了相应的光电导。实验结果表明(1)溅射α—Si:F薄膜有显著的光电响应;(2)光电导和暗电导的比值随气体的流量而接近成比例地变化。得到了最大σ_(ph)/σ_D比值为14000的薄膜样品;(3)溅射气氛中加入氢气对所得薄膜的光电导特性有一定影响。有关结果可用SiF_3、SiF_2H和SiFH_2键合组态的电子态不同解释。     

衬底温度对射频溅射a-Ge∶H薄膜光电性能的影响

本工作用射频溅射法制备出非晶和微晶锗氢膜(a-Ge∶H 和μc-Ge∶H).研究了衬底温度对薄膜光学、电学及结构性能的影响.结果表明:衬底温度 T_(?)<290℃,沉积出a-Ge∶H 膜;Y_(?)≥290℃沉积出μc-Ge∶H 膜.其结构、光电性能均当 T_(?)≥290℃时有明显的变化.     

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.