1-羟基-2-萘甲醛分子基态和激发态的质子转移机制

基于密度泛函与含时密度泛函理论方法,研究1-羟基-2-萘甲醛(HN12)分子及分子异构体在基态和激发态的氢键动力学过程.结果表明:在基态的HN12分子被激发至第一电子激发态后,出现氢键键长变短及氢键中羟基的红外光谱红移现象;激发态分子内的质子可发生转移反应;异构体在激发态时不易发生逆向的质子转移反应,但在基态较易出现逆向的质子转移过程.即HN12分子及分子异构体在基态和激发态存在一个循环机制.     

2-氨基-3-苯并恶唑喹啉水复合物激发态分子内与分子间质子转移的竞争机理

基于密度泛函与含时密度泛函理论方法, 研究2-氨基-3-苯并恶唑喹啉（ABO）水复合物(ABO-H₂O)激发态分子内与分子间质子转移的竞争机理. 结果表明： ABO-H₂O复合物中存在一个分子内的氢键和两个分子间的氢键; 基态ABO-H₂O复合物被激发至第一电子激发态后, 仅需越过一个34.157 kJ/mol能垒, 复合物即可发生激发态分子内的质子转移反应; ABO-H₂O复合物激发态分子间的双质子转移过程中存在一个63.585 kJ/mol能垒; 在第一电子激发态上, ABO-H₂O复合物中存在分子内与分子间质子转移的竞争机制; ABO-H₂O复合物更易出现激发态分子内的质子转移过程.     

N-甲基甲酰胺在水溶液中的氢键动力学行为

在B3LYP/6-31++G水平下,利用密度泛函理论方法优化了N-甲基甲酰胺单体和氢键体系NMF-nH2O(n=1,2,3)的基态几何构型;用含时密度泛函理论方法计算了N-甲基甲酰胺单体和氢键体系NMF-nH2O(n=1,2,3)在不同电子激发态的跃迁能、振子强度和电子吸收光谱.结果表明,随着结合水分子个数的增加,氢键强度是加强的.分子间氢键引起电子吸收光谱发生红移,光谱红移程度与氢键加强的程度一致.     

7-羟基黄酮分子在水中分子内电荷转移及分子间多重质子的转移

基于密度泛函和含时密度泛函理论的B3LYP方法, 在TZVP基组水平上模拟7-羟基黄酮(7HF)的水复合物--7HF-(H₂O)4激发态的动力学机制. 结果表明： 复合物中7HF在第一电子激发态的前线分子轨道出现分子内电荷转移过程; 复合物中7HF在基态和第一电子激发态发生了分子结构扭转, 复合物中5个分子间的氢键在第一电子激发态均出现加强机制, 该机制可以驱动激发态的多重质子转移反应.     

7-羟基黄酮分子在水中分子内电荷转移及分子间多重质子的转移机制

基于密度泛函和含时密度泛函理论的B3LYP方法,在TZVP基组水平上模拟7-羟基黄酮(7HF)的水复合物——7HF-(H_2O)_4激发态的动力学机制.结果表明:复合物中7HF在第一电子激发态的前线分子轨道出现分子内电荷转移过程;复合物中7HF在基态和第一电子激发态发生了分子结构扭转,复合物中5个分子间的氢键在第一电子激发态均出现加强机制,该机制可以驱动激发态的多重质子转移反应.     

N-苯甲酰基-N′-苯基硫脲-氨分子复合物的相互作用研究

采用GAUSSIAN98程序包密度泛函DFT(B3LYP)方法,在6-31G水平,优化得到了两个苯甲酰基苯基硫脲-氨分子复合物的结构.通过对所得到的分子复合物的分析,认为苯甲酰基苯基硫脲-氨分子复合物能够稳定存在;在两个分子复合物中,具有S…H-N以及N…H-N分子内氢键的复合物(b)的结构比既有O…H-N分子内氢键的复合物(a)更稳定.     

苯并三唑及其取代衍生物电子结构与光谱性质的理论研究

应用密度泛函理论(DFT)方法对苯并三唑(BTA)及其不同取代衍生物进行理论计算,讨论不同取代基对BTA分子的几何结构及电子结构的影响;同时,利用单激发组态相互作用(CIS)方法获得分子最低激发态结构,应用含时密度泛函理论(TD-DFT)方法研究分子的电子光谱性质.结果表明,BTA及其不同取代衍生物分子从基态到激发态的跃迁中,几何结构变化主要表现在苯环及共轭杂环的键长方面,最强跃迁均由分子的HOMO→LUMO跃迁贡献,由轨道对称性可知为π→π*跃迁.BTA分子中引入不同取代基,均导致吸收和发射光谱谱线红移.     

N-苯基-1,8-萘酰亚胺衍生物的电子结构和光谱性质的理论研究

采用密度泛函理论(DFT),在B3LYP/6-31+G(d)水平上对N-苯基-1,8-萘酰亚胺及其18种衍生物的几何结构进行全优化。在基态优化构型基础上,用含时密度泛函理论(TD-DFT)方法计算了该类物质在甲醇溶剂中的紫外可见吸收光谱。分析了分子几何构型、前线分子轨道的电子分布和轨道能级等特征,讨论了结构和吸收光谱之间的关系。结果表明,N-苯基-1,8-萘酰亚胺及其衍生物的稳定构型为非平面结构;其最强吸收光谱主要来源于HOMO→LUMO的π→π*跃迁。此外,在苯环上引入强推电子基团,能够显著降低HOMO与LUMO之间的能级差。     

激发态DNA碱基对分子间相互作用的理论研究

[目的]利用本课题组发展的定量分析方法研究激发态DNA碱基对分子间相互作用的本质,以及不同类型的电子跃迁对DNA碱基对分子间相互作用的影响.[方法]采用广义Kohn-Sham能量分解分析方法(generalized Kohn-Sham based energy decomposition analysis, GKS-EDA),对两种Waston-Crick构型和两种stacked构型的DNA碱基对分子间相互作用本质进行理论研究.[结果]对于Waston-Crick构型的碱基对,n→π^*跃迁削弱了轨道极化作用但加强了电子相关作用,激发态分子间相互作用由电子相关作用主导,而π→π^*跃迁对分子间氢键影响较小;对于stacked构型的碱基对,π→π^*跃迁削弱了静电相互作用但增强了电子相关作用.[结论] Waston-Crick构型碱基对分子间相互作用本质受电子激发跃迁影响较大,而电子激发跃迁基本不改变stacked构型碱基对分子间相互作用本质.     

邻-三氮杂苯-水复合物基态与最低激发态氢键结构

用密度泛函理论方法B3LYP和从头算方法MP2分别对邻-三氮杂苯和水形成1：1复合物的基态氢键结构进行几何优化和性质计算,结果表明复合物之间存在较强的氢键作用.在CASSCF（12,9）/6-31G^＊＊水平上对邻-三氮杂苯-水1：1复合物最低单重（n,π＊）激发态氢键结构的计算显示在对称氮原子N1（或N3）上形成了一个单氢键.     

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).     

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.