纳米TiO2/玻璃薄膜光催化降解亚甲基蓝的研究

用溶胶 -凝胶法在玻璃表面制备了均匀透明的纳米TiO2 薄膜 .采用高压汞灯为光源 ,敞口固定床反应器对水中染料亚甲基蓝进行了光催化氧化实验 .实验结果表明 :随着涂膜次数的增加 ,薄膜TiO2 负载量增加 ,锐钛矿晶相粒径增大 .TiO2 薄膜对亚甲基蓝氧化降解具有较高的光催化活性 ,降解反应符合一级速率方程 .对亚甲基蓝的暗态吸附及光催化降解机理作了初步探讨     

TiO2/SiO2气凝胶对亚甲基蓝降解的光催化活性

采用溶胶-凝胶过程和非超临界干燥法制备了TiO2/SiO2气凝胶,并对所得样品的结构进行了表征,研究了TiO2/SiO2气凝胶对亚甲基蓝(MB)降解的光催化活性.结果表明TiO2/SiO2气凝胶是一种轻质的连续多孔性块状材料,具有较高的机械强度;依据制备条件的不同,TiO2/SiO2气凝胶的比表面积在300～400m2·g-1范围内,平均孔径为20～40nm,孔体积在1～2cm3·g-1之间;TiO2/SiO2气凝胶对亚甲基蓝降解的光催化活性远高于粉末状的TiO2;钛硅的摩尔比n(TiO2)∶n(SiO2)=1∶6时制得的TiO2/SiO2气凝胶,经600℃焙烧热处理,在弱碱性条件下对亚甲基蓝降解的光催化活性较高;TiO2/SiO2气凝胶对亚甲基蓝降解反应的活化能为8.706kJ·mol-1.     

双元素掺杂纳米TiO2光催化降解亚甲基蓝的研究

以浸渍法、共沉淀法和溶胶-凝胶法制备得到了双元素钕和铁掺杂的纳米TiO2光催化剂,考察了它们对光降解亚甲基蓝的催化活性.结果表明,亚甲基蓝的光催化降解可用假一级动力学方程表示.以一定比例掺杂钕、铁离子可提高TiO2的光催化活性,尤其是在自然光下TiO2的光催化活性.在一定比例钕、铁掺杂后,共沉淀法制备的掺杂型TiO2的光催化活性接近于用溶胶-凝胶法制备的掺杂型TiO2.     

纳米Ti02／玻璃薄膜光催化降解亚甲基蓝的研究

用溶胶—凝胶法在玻璃表面制备了均匀透明的纳米TiO2薄膜．采用高压汞灯为光源，敞口固定床反应器对水中染料亚甲基蓝进行了光催化氧化实验．实验结果表明：随着涂膜次数的增加，薄膜TiO2负载量增加，锐钛矿晶相粒径增大．TiO2薄膜对亚甲基蓝氧化降解具有较高的光催化活性，降解反应符合一级速率方程．对亚甲基蓝的暗态吸附及光催化降解机理作了初步探讨。     

Sol-gel法制备纳米TiO2及其对亚甲基蓝染料光催化降解的研究

采用以溶胶-凝胶浸渍提拉法制备出玻璃负载纳米TiO2,并用以处理亚甲基蓝染料溶液,同时对玻璃负载的纳米TiO2薄膜进行了表征.通过SEM研究表明,玻璃负载的TiO2的直径介于30～50nm之间.研究表明其光催化活性随TiO2单位负载量的增加而增长,纳米TiO2光催化降解亚甲基蓝反应符合一级反应动力学方程,其表观速率常数为3.8×10-3/s.     

MoS2/TiO2纳米复合材料的制备与可见光光催化性能研究

采用TiO2溶胶-凝胶法制备了复合半导体MoS2/TiO2纳米材料,用XRD、UV-VIS-DRS、BET等手段对样品进行了表征,并以亚甲基蓝染料为探针分子详细讨论了MoS2掺杂量、染料初始浓度等对其光催化性能的影响.结果表明:MoS2/TiO2复合半导体纳米材料具有较好的可见光催化活性;当染料浓度为0.284mmol·L-1,催化剂用量为0.5 g·L-1,亚甲基蓝染料的光催化降解率为96.5%.     

钒氮共掺杂TiO2降解亚甲基蓝影响因素的研究

用溶胶-凝胶法制备钒氮共掺杂TiO2光催化剂,以亚甲基蓝的降解率为评价指标,考察钒氮共掺杂TiO2光催化降解亚甲基蓝的影响因素.结果表明,钒氮共掺杂能显著提高TiO2的光催化活性;在本实验条件下,钒氮添加量(与Ti的摩尔比)分别为0.1%、10%的TiO2于600℃焙烧、投入量为3g/L、溶液pH值为4~7、超声振荡30min、光照催化氧化处理4h的条件对处理低浓度亚甲基蓝溶液效果最好.     

TiO2-SnO2复合粉体光催化降解亚甲基蓝

以钛酸四丁酯和SnCl（4.5）H2O为先驱物,乙醇为溶剂,经过溶胶-凝胶法和热处理制备出TiO2-SnO2复合纳米粉体.探讨了掺杂锡量、热处理温度对TiO2-SnO2复合纳米粉体光催化降解亚甲基蓝的影响,采用X射线衍射分析了热处理过程中样品的晶型转化.考察了水溶液pH值和粉体用量对光降解速率的影响,分析了TiO2-SnO2粉体对亚甲基蓝降解过程的表观动力学特点.     

改性TiO2膜的制备及其光催化降解染料的研究

选用铝片为载体,以溶胶-凝胶法制得掺杂Ag的改性二氧化钛溶胶,采用拉膜法制得TiO2膜.用XRD、FT-IR对膜片的理化性能进行初步表征,并分别以甲基橙和亚甲基蓝作为目标降解物,考察了膜片在紫外光和可见光下的光催化活性.初步研究结果表明,Ag改性TiO2膜对染料表现出良好的光催化活性,当添加量为0.08 mol/L时,在254 nm的紫外光下对甲基橙的脱色率可达71%,在可见光下对亚甲基蓝的脱色率可达98%.     

Fe^3＋，Zn^2＋共掺杂高效纳米TiO2光催化剂的制备表征及光催化性能

利用溶胶-凝胶法制备了Fe3 ,Zn2 单一掺杂及共掺杂的纳米二氧化钛粉体,并用SEM,XRD对其进行了表面形貌和物相表征,模拟太阳光下对亚甲基蓝溶液进行了降解实验.结果表明,Fe3 ,Zn2 掺杂500℃度热处理2 h得到的二氧化钛均为锐钛矿相,共掺杂抑制TiO2晶粒长大的作用最明显,粒径最小.对亚甲基蓝的光催化实验表明,单一Zn2 或Fe3 掺杂对TiO2的光催化活性影响不大,而Fe3 ,Zn2 共掺杂能明显提高TiO2的光催化活性.催化剂的粒径大小以及共掺杂元素的协同作用可能是共掺杂提高光催化活性的主要原因.     

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.