热处理温度对纳米SnO_2与石墨复合材料电化学性能的影响

用微乳液法制备了纳米SnO2与石墨复合材料作为锂离子电池负极材料,并对其用不同温度进行了热处理.用X-射线衍射(XRD)和透射电子显微镜(TEM)对复合材料进行了表征,并用恒流充放电法考察了试样的电化学性能.对比结果表明,复合材料有着较高的循环容量,不同热处理温度对复合物的电化学性能有着明显的影响.随着热处理温度的升高,电池的循环容量都明显增加,但不可逆容量也随之增加.     

Sn-基复合氧化物的制备及电化学性能研究

采用一种流变相法制备掺杂B和P非金属元素的SnO复合氧化物（TBP）,对不同温度下热分解得到的产物结构及作为锂二次电池负极材料的电化学性能进行表征。结果表明,以比容量和循环性能折中考虑,500℃热处理试样的电化学性能较好。     

溶胶-凝胶法制备纳米SnO2

运用溶胶-凝胶法合成前驱物Sn（OH）4胶体，在不同温度下加热分解得到一系列纳米SnO2试样，并用X-射线衍射（XRD）图谱和透射电子显微镜（TEM）表征不同温度下热处理得到试样的结构和形貌，研究了分解温度与产物粒径大小之间的关系以及微晶生长动力学。     

多孔纳米Mg-Sn金属复合氧化物的制备及性能表征

采用液相沉淀法制备Mg-Sn金属复合氢氧化物前驱体，在不同温度下加热分解，得到一系列Mg-Sn金属复合氧化物；通过差热及热重分析仪（TG／DTA）、X-射线衍射仪（XRD）和透射电子显微镜（TEM），分析了其前驱物、产物的结构、组成及形貌等特征。结果表明：Mg-Sn金属复合氢氧化物前驱体热分解得到的是多孔纳米材料，且低温（400，600，700℃）热分解得到的是非晶态的MgSnO3复合氧化物，高温（750，850℃）热分解得到的是四方相的MgSnO3和少量尖晶石型Mg2SnO4，900℃热分解得到的是MgO和SnO2的混合物。所得Mg-Sn金属复合氧化物均为多孔材料，而且孔径、结晶度及电化学性能均依赖于分解温度。若从容量和循环寿命折中考虑，850℃热分解试样的电化学性能最优。     

溶胶-凝胶法制备纳米SnO2

运用溶胶-凝胶法合成前驱物Sn(OH)4胶体,在不同温度下加热分解得到一系列纳米SnO2试样,并用X-射线衍射(XRD)图谱和透射电子显微镜(TEM)表征不同温度下热处理得到试样的结构和形貌,研究了分解温度与产物粒径大小之间的关系以及微晶生长动力学.     

SnO2／碳纳米管纳米复合材料的制备及表征

采用水热的方法,将纳米SnO2负载在多壁碳纳米管（CNTs）表面,制备得到SnO2负载多壁碳纳米管复合材料（SnO2／CNTs）。通过X射线衍射（XRD）和扫描电子显微镜（SEM）研究了不同反应条件对产物形貌的影响。结果表明,通过改变溶液的浓度可以控制SnO2／CNTs纳米复合材料的形貌。     

纳米TiO2/SnO2涂层的制备与光阴极保护性能

采用溶胶-凝胶法在304不锈钢表面制备了纳米TiO2/SnO2叠层涂层.通过测量稳定电位研究了涂层的光电化学性能和光阴极保护特性,用扫描电子显微镜、X射线衍射和X射线光电子能谱对涂层的表面形貌、晶体结构与组成进行了表征.结果表明:纳米TiO2表层与纳米SnO2内层分别浸渍提拉4次制得的叠层涂层具有最好的光电化学效应、储存电子性能与光阴极保护作用,紫外光照1h的延时阴极保护作用可达7h;纳米叠层涂层表面连续、均匀致密;TiO2为锐钛矿型,SnO2为金红石型;涂层表面与内层均由Ti、Sn、O和C元素组成.文中还探讨了纳米TiO2/SnO2叠层涂层的光阴极保护作用机理.     

Fe基非晶及纳米晶在硫酸中的腐蚀研究

利用电化学极化曲线的方法和电化学阻抗技术,研究非晶Fe78Si13B9和纳米晶Fe73.5Si13.5B9Nb3Cu1合金在1 mol·L-1的H2SO4溶液里的电化学腐蚀行为;利用X射线衍射仪和示差扫描量热计(DSC),研究该非晶薄带的非晶特性及晶化过程;用扫描电镜观察极化测试后的试样形貌;还研究不同的热处理温度对材料的结构及在1 mol·L-1的H2SO4溶液里耐腐蚀性能的影响.结果表明,纳米晶比非晶合金的耐腐蚀性能要好;随着热处理温度的升高,非晶的耐腐蚀性能得到提高,而纳米晶则降低.     

高分子修饰方法制备纳米SnO2

采用高分子修饰法制备出粒径较小的纳米snO2.研究了不同的反应介质和不同的Sn4+/PVP的配比对纳米SnO2颗粒的尺寸及紫外吸收性能的影响.结果表明,高分子修饰法制备的纳米SnO2极其稳定,且粒径较小.     

复合SnO2/TiO2纳米颗粒的制备与性质研究

本文采用均匀沉淀法制备了复合SnO2／TiO2纳米颗粒,重点考察了水解温度、水解时间、焙烧温度等制备条件对复合纳米颗粒性质的影响;在优化条件下制得的复合SnO2／TiO2纳米颗粒,利用XRD等对其结构、粒子粒径、晶型等进行了表征;并以对-二甲苯为目标污染物考察了其光催化性能。实验结果表明,控制水解温度维持在80℃时,水解时间为4h,得到SnO2／TiO2纳米颗粒,并且复合SnO2／TiO2纳米颗粒随焙烧温度的增加,其粒子粒径长大,晶型由锐钛矿向金红石型转变;同时复合SnO2／TiO2纳米颗粒的光催化性能随着焙烧温度的升高而降低。     

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.