喹啉水溶液与羟基自由基的作用机理研究

利用脉冲辐解技术对喹啉水溶液与羟基的作用机理进行了详细研究,对其瞬态吸收峰进行了归属,初步考察了这些瞬态粒子的生成和衰减行为。研究表明,·OH 与喹啉在碱性条件下反应生成 OH-加合物,生成速率常数为5.2×10~(10)mol~(-1)·s~(-1);在酸性条件下喹啉先与氢离子反应生成喹啉阳离子,它再与羟基发生加成反应,反应速率常数为7.90×10~(10)mol~(-1)·s~(-1),从而为喹啉的氧化降解提供了理论基础。     

理论研究单个水或甲酸分子对乙酰基异构化的影响

在M06-2X、B3LYP、MP2和MC-QCISD水平下,理论研究了大气中的单个水和甲酸分子催化乙酰基异构化的反应机理,发现产物均为CH2COH自由基。研究结果表明,裸反应的活化能为81.2kcal·mol-1,而加上水和甲酸分子活化能分别降低到46.2和29.0kcal·mol-1,表明它们均能与乙酰基通过氢键形成稳定的络合物,以便有效地催化异构化反应。在298K,1标准大气压条件下,通过直接动力学计算发现,裸反应的速率常数为6.49×10-47cm3·molecule-1·s-1,水和甲酸催化反应比其速率常数分别增加24和33个数量级。考虑大气中各物种浓度后,发现裸反应速率为4.96×10-29s-1,水或甲酸催化该反应的速率分别为2.55×107和9.52×109s-1,当大气中水分子或甲酸浓度较高时,乙酰基异构化反应生成CH2COH自由基可能性很大。     

Zn(Ⅱ)-1,3,5-三(2',5'-二氮辛烷基)苯配合物催化酯类水解动力学研究

合成了一个含有六个氮原子的三脚架配体1,3,5-三(2',5'-二氮辛烷基)苯,并用初始浓度法对其Zn(Ⅱ)配合物催化对硝基苯酚醋酸酯(NA)水解的反应动力学进行了研究.得到二级速率常数kZn3L、kZn3LH-1分别为0.0059mol-1·dm3·s-1和0.382mol-1·dm3·s-1.拟合得到Zn3L的去质子化常数pKa为7.44,与滴定所得到的7.52基本一致.对配合物的催化能力与其它模型进行了比较.     

Zn（Ⅱ）－1，3，5－三（2′，5′－二氮辛烷基）苯配合物催化酯类水解动力学研究

合成了一个含有六个氮原子的三脚架配体1,3,5-三(2',5'-二氮辛烷基)苯,并用初始浓度法对其Zn(Ⅱ)配合物催化对硝基苯酚醋酸酯(NA)水解的反应动力学进行了研究.得到二级速率常数kZn3L、kZn3LH-1分别为0.0059mol-1·dm3·s-1和0.382mol-1·dm3·s-1.拟合得到Zn3L的去质子化常数pKa为7.44,与滴定所得到的7.52基本一致.对配合物的催化能力与其它模型进行了比较.     

氮氧自由基对苯甲酮三重激发态猝灭反应的TR-EPR研究

利用TR-EPR技术并结合瞬态吸收光谱方法研究了乙二醇(EG)均相溶液中稳态自由基TEMPO对光诱导苯甲酮三重激发态3BP*的猝灭反应,分析了其中的光化学反应中间体,讨论光解自由基的CIDEP机理,测量了TEMPO对3BP*的猝灭速率常数.结果表明,EG均相溶液中BP*与溶剂分子EG之间存在氢原子转移反应,生成苯甲酮中性自由基BPH·和乙二醇羰自由基Egl[-H]·.E+E/A的CIDEP信号说明TM机理是体系CIDEP的主要机理.另外,TEMPO对3BP*也有明显的猝灭作用,猝灭速率常数为1.40×107L.mol-1·s-1.     

荧光法研究咖啡酸及其衍生物与溶菌酶的相互作用

应用荧光光谱法研究了咖啡酸(CA)、阿魏酸(FA)、绿原酸(CAL)与溶菌酶(Lyz)的相互作用.通过不同浓度的有机酸对Lyz内源荧光的猝灭,测定了各有机酸与Lyz结合反应的stern-volmer猝灭速率常数、结合常数、结合位点数.结果显示在0.1≤c有机酸/cLyz≤5范围内,stern-volmer猝灭速率常数CA对Lyz为2.83×1012 L·mol-1·s-1,CAL对Lyz为3.09×1012 L·mol-1·s-1,而FA对于Lyz为2.32×1012 L·mol-1·s-1(0.1≤cFA/cLyz≤4的浓度范围内),均为静态猝灭机制.CA、FA、CAL与Lyz之间形成了复合物,结合常数分别为KCA/Lyz=1.53×106 L·mol-1、KFA/Lyz=1.36×105 L·mol-1、KCAL/Lyz=1.56×105 L·mol-1,各有机酸与Lyz之间的结合比均为1∶1,有机酸中的-COOH对结合位点数起主要作用.     

基于三角架配体的硝酸钴配合物的酯催化水解动力学与机理研究

利用三脚架配体-钴(Ⅱ)配合物作为催化剂进行了水解催化4-硝基苯酚醋酸酯(NA)的研究.在pH7.5-9.4范围生成钴(Ⅱ)金属配合物(配体∶钴离子=1∶3),在25℃和不同的pH值条件下(pH7.5-9.4),通过观察4-硝基苯酚的释放速率研究了钴配合物催化4-硝基苯酚醋酸酯的水解反应动力学.结果表明,钴(Ⅱ)配合物可以作为有效的亲核试剂催化NA酯水解,水解速率v=(koMbsL[ML] kOH[OH-] k0)[NA],二级水解速率常数为0.197 mol-1.dm3.s-1.     

硅粉常压直接氮化过程的非催化气固反应模型

以平均粒径2.2μm、纯度99.99%的硅粉为原料,采用纯度99.993%的高纯氮气作为反应气体,在1350和1400℃下进行了氮化时间为10～30 min的氮化实验,得出了不同温度下硅粉转化率随反应时间的变化关系.将硅氮反应看成非催化气固反应,建立了硅颗粒氮化动力学模型.通过对实验数据的拟合,得出两个模型参数:硅氮反应速率常数和氮气在产物层中的扩散系数.假定反应速率常数和扩散系数均满足阿伦尼乌斯公式,求得化学反应激活能和指前因子分别为2.71×104J·mol-1和3.07×10-5m·s-1,扩散激活能和指前因子分别为1.06×105J·mol-1和1.12×10-9m2·s-1.利用本文得出的氮化动力学模型对各温度下不同粒径硅粉的转化曲线进行了预测,预测曲线与文献中的实验数据在趋势上吻合较好.     

聚叠氮缩水甘油醚GAP热分解特性研究

在升温速率分别为2℃·min-1,5℃·min-1,10℃·min-1,20℃·min-1条件下,采用差示扫描量热仪(DSC)和热重分析技术研究了聚叠氮缩水甘油醚GAP的热分解特性,并在此基础上考察了GAP的动力学参数和热力学参数.结果表明GAP热分解峰温较高,热稳定性较好.采用Kissinger法和Ozawa-Doyle法讨论了热分解的表观活化能、指前因子、120℃时的分解速率常数k,其值分别为196.82 kJ·mol-1、4.47×1019 s-1、3.15 ×10-7 s-1.在218℃时热力学参教的活化熵为127.13 J·mol-1·K-1,活化焓为196.82kJ· mol-1,活化自由能为134.38 kJ·mol-1.     

桃胶多糖酸水解的规律

为有效控制桃胶多糖的水解,以桃胶多糖为原料,用DNS法测定其在pH=1及不同水解温度和时间下的单糖的含量,进而计算出水解度. 结果表明桃胶多糖的酸水解属于拟一级反应类型;在70、75、80、85、90、95 ℃反应时其表观反应速率常数分别是1.72×10-5 s-1 、 3.74×10-5 s-1 、 5.77×10-5 s-1 、 9.41×10-5 s-1、 1.45×10-4 s-1、 2.23×10-4 s-1 ,其水解反应的表观活化能是1.03×105 J·mol-1,反应的表观频率因子是9.72×1010. 在实验温度范围内反应速率常数温度的升高而增大,且两者之间的关系符合Arrhenius公式. 总结出桃胶多糖酸水解反应的Arrhenius公式是k=9.72×1010exp(-1.03×105/RT),进而得到水解度为1-1/exp{[9.72×1010exp(-1.03×105/RT)]t}     

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.