TiO2的微波辐射Sol-Gel法制备及其光催化性能

采用微波辐射Sol-Gel法在石英砂表面制备负载型TiO2光催化剂，考察不同加热方式。微波功率以及微波加热温度对溶胶质量的影响，微波加热反应制备的溶胶粒子平均粒径小于常规加热反应制备得到的溶胶粒子，微波加热反应适宜条件是微波功率600W，反应温度为90℃、以苯酚为光催化降解研究对象，考察了两种方式制备的负载型TiO2光催化剂的催化性能，实验结果表明微波辐射Sol-Gel法制备的负载型TiO2光催化剂光催化性能也优于常规Sol-Gel法制备的负载型TiO2光催化剂。     

TiO2-ZrO2复合催化剂上乙烯的光催化降解

采用溶胶 -凝胶技术制备了系列TiO2 -ZrO2 复合催化剂 ,运用X -射线粉末衍射和低温N2 吸附测定表征了其结构性质 .考察了制备方法、ZrO2 添加量及焙烧温度等对反应活性的影响 .结果表明 ,以锆的无机盐为前驱体采用混胶法制备的TiO2 -ZrO2 复合催化剂的光催化活性最佳 ,TiO2 催化剂中ZrO2 粒子的引入能增大光催化剂的比表面积、抑制TiO2 晶相转变和促使UiO2 晶粒细化 ,从而提高了催化剂光催化降解乙烯的活性和抗失活稳定性 ,但ZrO2 含量增加时其光催化反应的矿化率降低 .     

TiO2光催化剂载体的选型及负载方法研究

选择Al2O3空心颗粒、石英管和玻璃珠等为载体制备了几种负载型TiO2光催化剂，并通过十二烷基苯磺酸钠(简称DBS)的光降解反应研究了催化剂负载方法及其对催化剂活性的影响，确定了制备负载型TiO2光催化剂的最佳负载方法。     

超声波制备TiO_2光催化降解气相苯的研究

文章以钛酸四丁酯为原料,采用超声波分散450℃焙烧物得到了纳米TiO2光催化剂,以苯为模拟气体,在静态反应装置中考察了该催化剂对气相苯的光催化降解性能。结果表明,采用超声波制备的TiO2光催化剂能显著提高对苯的光催化降解性能,超声波制备的TiO2上苯转化率是搅拌制备的TiO2的1.7倍。BET结果显示超声波制备的光催化剂比表面比搅拌制备的光催化剂高;XRD表征结果表明TiO2呈锐钛型;紫外-可见漫反射结果显示超声波制备的TiO2在可见区吸收增强。     

WO_3/TiO_2（NT）/UV降解处理印染废水研究

以钨酸铵为钨源,介孔TiO2纳米管为载体,采用传统浸渍方法制备了WO3/TiO2纳米管复合材料。讨论了以WO3/TiO2纳米管为催化剂,影响印染废水光催化脱色的主要因素,实验结果表明：光催化降解印染废水符合一级反应动力学反应过程。以500℃焙烧的WO3/TiO2纳米管复合材料为光催化剂,当催化剂用量为500mg/L,UV光照2h,印染废水的脱色率达到97%以上。另外,催化剂具有较高的稳定性,失活后的催化剂可以通过简单的焙烧再生。     

附载光催化剂TiO2/活性炭光催化氧化NO2-的研究

探讨了光催化剂TiO2/C的制备条件和不同制备条件对NO2-的光催化氧化效果.研究表明,制备TiO2/C的最佳条件为Ti(OCH3)4的用量为10 ml,附载光催化剂样品在400℃下焙烧5 h,TiO2/C的用量为0.5 g时光催化效果最好.     

掺锡TiO2复合颗粒的制备和日光催化的研究

采用实验室合成的掺锡TiO2作为光催化剂，以罗丹明B降解反应为模型，研究了不同制备条件(反应时间、反应温度、氨水用量和掺杂量)和不同反应降解体系(催化剂用量、pH值)对掺锡TiO2降解罗丹明B的影响,实验结果表明，不同制备条件对产品的光催化活性有较大的影响，是决定产品光催化活性的关键因素,催化剂用量对罗丹明B降解起双重作用,酸性强的反应体系有利于罗丹明B的降解。     

Cr2O3-TiO2负载金属光催化剂及其光分解水产氢性能研究

以钛酸四丁酯和重铬酸铵为原料,采用溶胶凝胶法制备Cr2O3 TiO2 复合型光催化剂,并利用浸渍法在Cr2O3 TiO2 表面分别负载Fe、Mn、Mo 过渡金属,制备了Fe Cr2O3 TiO2、Mn Cr2O3 TiO2、Mo Cr2O3 TiO2 三元复合型光催化剂.通过X射线衍射(XRD)、比表面分析(BET)和紫外可见吸收光谱(Uv Vis)对催化剂进行了表征.XRD结果表明:TiO2 为金红石结构;Cr2O3 为绿铬矿结构.催化剂在紫外光和可见光条件下均具有光催化分解水产氢活性,紫外光条件下三元复合型光催化剂可以明显提高光催化产氢活性,其中Mo Cr2O3 TiO2 活性最高,而在可见光条件下,三元复合型光催化剂产氢活性略低于Cr2O3 TiO2.     

Ce/S共掺杂TiO2制备及其光催化活性

采用溶胶-凝胶法制备了沸石负载型Ce/S共掺杂TiO2光催化剂,探讨了可见光下负载型共掺杂TiO2光催化剂的光催化降解亚甲基蓝的可行性和工艺条件.研究结果表明,催化剂焙烧温度300℃,反应体系pH值为7.02时的亚甲基蓝降解效果最好.共掺杂复合光催化剂活性要好于单掺杂和不掺杂的光催化剂活性,负载型复合光催化剂具有很好的重复使用性能.     

微波辅助法制备纳米TiO_2及其光催化性能

在微波条件下采用Sol-Gel法制备了纳米TiO2光催化剂，通过XRD，TEM，BET，荧光吸收等考察了焙烧温度对TiO2结构的影响。以光催化降解苯酚反应为探针，考察了微波对于TiO2活性的影响。结果表明，微波用于凝胶合成能够显著提高TiO2的光催化活性，降低由锐钛矿型向金红石型的转化温度。这主要归因于微波加热可以提高反应物的分散度，在低温焙烧就可得到高结晶度的锐钛矿型TiO2，且晶粒均匀。     

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.     

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…     

Perspherical Approaches for Electrons in Atoms and Charged Excitons in Quantum Wells

Instead of following Fock’s expansion,we solve the Schrodinger equation for some quantum mechanical manybody systems such as electrons in atoms and charged excitons in quantum wells in a similar way in hyperspherical coordinates by expanding the wave functions into orthonormal complete basis sets of the hyperspherical hannonics(HHs)of hyperangles and generalized Laguerre polynomials(GLPs)of the hyperradius.This leads the equation to     

Advances in broadband wireless communications under high-mobility scenarios

Future mobile communication systems aim at providing very high data transmission rates, even in high-mobility scenarios such as high-speed wheel-track trains, maglev trains, highway vehicles, airplanes, guided missiles or spacecraft. A particularly important commercial application is the strong and increasing worldwide demand for high- speed broadband wireless communications （up to 574.8 km/ h test speeds or 380 km/h commercial speeds） in railways, providing data, voice and video services for applications such as onboard entertainment services to passengers, train control, train dispatch, train sensor status handling and sur- veillance. In such high-mobility scenarios, there are a number of communication challenges, including fast hand- over, location updating, high-speed channel modeling, estimation and equalization, anti-Doppler spreading tech- niques, fast power control, and dedicated network architec- ture. Because signal transmission in very high-speed scenarios will inevitably experience serious deterioration, it is imperative to develop key broadband mobile communi- cation techniques for such high-speed vehicles.     

Wuhan University Journal of Natural Sciences TOTAL CONTENTS

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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。     

Scale-based spatial data model for GIS

Being the primary media of geographical information and the elementary objects manipulated, almost all of maps adopt the layer-based model to represent geographic information in the existent GIS. However, it is difficult to extend the map represented in layer-based model. Furthermore, in Web-Based GIS, It is slow to transmit the spatial data for map viewing. In this paper, for solving the questions above, we have proposed a new method for representing the spatial data. That is scale-based model. In this model we represent maps in three levels: scale-view, block, and spatial object, and organize the maps in a set of map layers, named Scale-View, which associates some given scales.Lastly, a prototype Web-Based GIS using the proposed spatial data representation is described briefly.     

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