快速高温热退火对InGaNAs/GaAs量子阱的影响

从系统自由能角度,阐明了MBE生长的InGaNAs量子阱材料在高温热退火过程中的结构和物理性能的变化。在热退火时,In-Ga互扩散和N-As互扩散引起spinodal分解,N原子趋向于与In结合形成In-N键,使InGaNAs材料的带隙增加,从而引起PL谱峰值的蓝移。     

InGaAs／InP量子阱材料生长后置无序技术的研究

研究了氖离子注入诱导ＩｎＧａＡｓ／ＩｎＰ量子阱材料带隙变化的规律，研究结果表明，由氖离子注入引起量子阱带隙蓝移。蓝移的大小与量子阱的宽度，阱距表面深度，注入离子剂量，能量，及退火条件有关，研究所得的参数对设计量子阱集成光器件有重要参考价值。     

InGaAs/InP量子阱材料生长后置无序技术的研究

研究了氖离子注入诱导 In Ga As/In P量子阱材料带隙变化的规律 .研究结果表明 ,由氖离子注入引起量子阱带隙蓝移 .蓝移的大小与量子阱的宽度 ,阱距表面深度 ,注入离子剂量 ,能量 ,及退火条件有关 .研究所得的参数对设计量子阱集成光器件有重要参考价值     

InGaAs/InGaAsP量子阱激光器材料带隙蓝移研究

为了在光开关器件的制作中实现低传输损耗的光波导 ,对InGaAs/InGaAsP分别限制异质结多量子阱 (SCH MQW )激光器结构进行了一系列带隙蓝移实验 .将能量 12MeV、注量 15×10 13cm- 2 的P+注入到实验样品后 ,在 70 0℃下快速热退火 90s.发现光致发光谱的峰值位置发生蓝移 989nm .蓝移量随着注入能量和注量的增大而增大 ,并且能量比注量对蓝移的影响更大 .     

聚集激光束实现ＩnGaAsP超晶格量子阱混合

研究了晶格与ＩｎＰ匹配的ＩｎＧａＡｓＰ超晶格材料的热稳定性，实验结果表明在６００℃以上的热退火下会产生量子阱混合，采用１．０６４μｍ连续输出的Ｎｄ：ＹＡＧ 激光器对超晶格外延片进行了聚集辐照，室温光荧光谱得到了１８４ｍｅＶ的蓝移，说明激光辐照与热退火一样会产生量子阱混合效应，光荧光谱的双峰位表明运用激光处理量子阱外延惩具有一定的空间选择性，衬底预加热和激光束的聚焦可以在不减弱处理效果的情况下有效地     

InGaAsP四元系量子阱材料的热稳定性

对与ＩｎＰ晶格匹配的ＩｎＧａＡｓＰ四元系量子阱材料进行了一系列热稳定性能的研究，通过光荧光谱（ＰＬ）的测量发现：ＩｎＧａＡｓＰ四元系量子阱材料在６５０℃以上的常规退火条件下有量子阱混合现象产生，而单量子阱结构较多量子阱或超晶格结构更容易产生量子阱混合。对单量子阱片进行快速退火处理后，荧光峰位置、峰宽无明显变化，表明量子阱混合的产生除了依赖于退火温度的高低，也与退火时间的长短密切相关。     

InGaAsP四元系量子阱材料的热稳定性

对与ＩｎＰ晶格匹配的ＩｎＧａＡｓＰ四元系量子阱材料进行了一系列热稳定性能的研究，通过光荧光谱（ＰＬ）的测量发现：ＩｎＧａＡｓＰ四元系量子阱材料在６５０ ℃以上的常规退火条件下有量子阱混合现象产生，而单量子阱结构较多量子阱或超晶格结构更容易产生量子阱混合．对单量子阱片进行快速退火处理后，荧光峰位置、峰宽无明显变化，表明量子阱混合的产生除了依赖于退火温度的高低，也与退火时间的长短密切相关．     

聚焦激光束实现InGaAsP超晶格量子阱混合

研究了晶格与 In P匹配的 In Ga As P超晶格材料的热稳定性 ,实验结果表明在 60 0℃以上的热退火下会产生量子阱混合 .采用 1 .0 64 μm连续输出的 Nd∶YAG激光器对超晶格外延片进行了聚焦辐照 ,室温光荧光谱得到了 1 84 me V的蓝移 ,说明激光辐照与热退火一样会产生量子阱混合效应 ,光荧光谱的双峰位表明运用激光处理量子阱外延片具有一定的空间选择性 .衬底预加热和对激光束的聚焦可以在不减弱处理效果的情况下有效地减少激光辐照的时间 ,以减小晶格损伤     

直接带隙Ge/Si_(1-x)Ge_x量子阱中激子态和带间光跃迁

利用有效质量近似和变分原理,对直接带隙Ge/Si1-x Gex量子阱中激子态和带间光跃迁进行研究.结果表明:直接带隙Ge/Si1-x Gex量子阱中带间光跃迁能、激子复合时间和基态振子强度依赖于阱宽和Si1-x Gex中Ge含量.当阱宽大于30nm时,跃迁能、激子复合时间、振子强度对Ge含量和阱宽的变化不敏感;基态线性光极化率随着Ge含量的增加而减小,同时光极化率峰值所对应的光子能量减小.     

SiOP介质膜及其对InGaAsP/InP量子阱激光结构混合无序的影响

用等离子体增强化学沉积(PECVD)方法制备了一种新的电介质薄膜—SiOP,用X射线光电子谱(XPS)和光荧光(PL)研究了膜的结构及膜对1.55μmInGaAsP/InP量子阱激光结构带隙的影响.XPS分析表明,该膜中存在SiO和PO键,P(2p)态键能为134.6eV.PL测量首次获得223.6meV的最大带隙蓝移.该技术在光子集成和光电子集成电路(PIC's,OEIC's)中有广泛的应用前景.     

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.