静电纺载纳米银粒子纳米复合纤维的制备及其结构与性能

利用静电电纺丝法制备了Ag/PAN复合的纳米纤维,通过扫描电镜(SEM)和能谱分析(EXD)分别分析载纳米银粒子的形貌和成分,研究了载纳米银粒子纳米纤维的银粒子释放率及抗菌性能.结果表明,利用静电电纺丝法制备的载纳米银粒子的纳米纤维具有较好的形貌,呈现出缓慢持久的纳米银粒子释放率,具有良好的生物抗菌性能.     

硫酸钡纳米粒子制备方法研究

研究了制备纳米BaSO4粒子的多种制备方法,用透射电子显微镜和激光粒度分析仪对合成纳米粒子的形貌、大小及粒度分布进行了表征分析,实验发现不同制备方法对纳米粒子大小及形貌均有影响,同时各种制备方法所得的纳米BaSO4粒子平均粒径小、分布窄,并探讨了各种方法的反应机理.     

银纳米材料制备和应用进展

 银纳米复合材料由于其优良的综合性能而具有广阔的应用前景,已成为纳米材料研究的热点。本文综述了银纳米颗粒和银纳米复合材料的化学制备方法,包括化学还原法、光还原法、微乳液法、电化学法等,指出了化学还原法由于容易控制粉末粒度和形貌,生产成本相对较低,是目前研究和应用最广的制备纳米银粉的方法,在制备过程中加入保护剂是防止纳米银颗粒团聚的有效方法;分析了银纳米材料在催化材料、抗菌材料、电子电路、表面增强拉曼光谱及其他领域的应用,复合银纳米材料已经在乙烯氧化制环氧乙烷催化剂和抗菌塑料中得到商业化应用;提出制备尺寸可控、形貌可控的银纳米粒子以及各种新型功能性银纳米材料将是今后研究的方向。     

硫酸钡纳米粒子制备方法研究

研究了制备纳米BaSO4粒子的多种制备方法，用透射电子显微镜和激光粒度分析仪对合成纳米粒子的形貌、大小及粒度分布进行了表征分析，实验发现不同制备方法对纳米粒子大小及形貌均有影响，同时各种制备方法所得的纳米BaSO4粒子平均粒径小、分布窄，并探讨了各种方法的反应机理．     

金属纳米银粒子复合膜吸收红移和展宽现象

通过溶胶凝胶法(Sol-Geltechnique),从银胶中获得纳米银粒子,将金属纳米银粒子掺入明胶基质中,从而制备出金属纳米银粒子复合膜.电镜(TEM)测量结果表明,所掺入的银粒子确属纳米量级.与纳米银粒子溶胶相比,复合膜中银颗粒尺寸分布变宽,颗粒平均尺寸增大.实验测试了复合膜的紫外可见光范围的光吸收性质,发现其存在吸收谱展宽和吸收峰红移现象,并用量子阱理论给予解释.     

含Ag-乙二醇纳米流体的制备及其导热性能研究

本文在室温下采用直接还原法制备了含PVP表面修饰、高负载量的纳米银-乙二醇纳米流体。实验详细比较了各种反应条件对Ag纳米粒子结构、大小、形貌以及乙二醇纳米流体的稳定性、负载量的影响。结果表明：由于PVP对银粒子有良好的表面修饰作用和纳米粒子自身的布朗运动,使得银粒子能够稳定地分散于乙二醇流体中。当PVP含量为12.5 g.L-1时,Ag粒子最大负载量可以达到20.96 g.L-1。同时采用仿制的纳米流体导热系数测试装置测定了上述不同负载量流体的导热系数,结果表明纳米流体比纯乙二醇的导热系数明显提高,当银粒子的体积分数为0.06%时,纳米流体的导热系数提高了36%。     

液相化学还原法制备纳米银和纳米铜粒子

以十六烷基三甲基溴化铵为保护剂,葡萄糖为还原剂,利用液相化学还原法成功的制备了纳米银和纳米铜粒子.利用透射电子显微镜(TEM),X射线衍射(XRD)对样品的形貌和结构进行了分析结果表明,所制得的纳米银和纳米铜为纯银和纯铜.且硝酸银的浓度、反应时间对纳米银形貌及粒径有着很大的影响.当选择合适的硝酸银浓度及反应时间,能够制备平均粒径为10 nm、粒径均匀、单分散的纳米银粒子.另外,UV光谱也证实,所制的溶胶为粒径均匀的纳米银和纳米铜溶胶.     

液相化学还原法制备纳米银和纳米铜粒子

以十六烷基三甲基溴化铵为保护剂,葡萄糖为还原剂,利用液相化学还原法成功的制备了纳米银和纳米铜粒子.利用透射电子显微镜(TEM),X射线衍射(XRD)对样品的形貌和结构进行了分析结果表明,所制得的纳米银和纳米铜为纯银和纯铜.且硝酸银的浓度、反应时间对纳米银形貌及粒径有着很大的影响.当选择合适的硝酸银浓度及反应时间,能够制备平均粒径为10 nm、粒径均匀、单分散的纳米银粒子.另外,UV光谱也证实,所制的溶胶为粒径均匀的纳米银和纳米铜溶胶.     

纳米Co3O4粒子制备新方法

采用一种新方法———接枝羧基淀粉(ISC)吸附金属离子前驱物(ISC Co)热解法, 制备了粒度分布均匀、分散性好的Co3O4 纳米颗粒. 该法分为3步: ISC的合成; ISC Co的制备; ISC Co分解及 Co3O4 纳米颗粒的晶相转化.对 ISC 和 ISC Co的红外光谱(IR)进行了对比和讨论, 利用差热 热重(DTA TG)分析法研究了前驱物的分解过程; 通过X射线衍射(XRD)数据分析了Co3O4 纳米颗粒的晶相, 借助透射电镜(TEM)观察了纳米粒子的形状和尺寸分布.     

含Ag-乙二醇纳米流体的制备及其导热性能

在室温下采用直接还原法制备了含PVP表面修饰、高负载量的纳米银-乙二醇纳米流体。实验详细比较了各种反应条件对Ag纳米粒子结构、大小、形貌以及乙二醇纳米流体的稳定性、负载量的影响。结果表明:由于PVP对银粒子有良好的表面修饰作用和纳米粒子自身的布朗运动,使得银粒子能够稳定地分散于乙二醇流体中。当PVP含量为12.5 g·L~(-1)时,Ag粒子最大负载量可以达到20.96 g·L~(-1)。同时采用仿制的纳米流体导热系数测试装置测定了上述不同负载量流体的导热系数,结果表明纳米流体比纯乙二醇的导热系数明显提高;当银粒子的体积分数为0.06%时,纳米流体的导热系数提高了36%。     

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.