纳米多金属氧酸盐的制备方法

由于纳米级多金属氧酸盐具有优异的光、电、磁等方面的催化活性，因此介绍了近年来见诸干研究中的九种纳米多金属氧酸盐的制备方法和原理，它们分别是浸渍法、真空法、阳离子交换法、微乳法、固相合成法、表面修饰法、两步法、层接层法、溶胶-凝胶法，并比较了它们各自的物化特性，总结了这些方法制备的纳米多金属氧酸盐在催化领域中的应用前景。     

多金属氧酸盐催化氧化脱硫研究进展

多金属氧酸盐以其独特的酸性、多功能性及"假液相"行为广泛应用于各种酸催化以及氧化还原反应体系中.近年来,多金属氧酸盐在催化氧化脱硫领域更是得到了长足的发展.文中详细地阐述了具有Keggin、Dawson及Anderson等不同结构的多金属氧酸盐与表面活性剂或离子液体结合而形成的新型催化剂在氧化脱硫领域中的研究进展.总结了以金属氧化物、分子筛及活性碳为载体所制备的负载型多金属氧酸盐催化氧化脱除模拟油品或FCC汽油中噻吩、苯并噻吩或二苯并噻吩的反应性能.并对多金属氧酸盐系列催化剂在氧化脱硫中的未来发展方向进行了展望,指出了选择具有高活性、高选择性、高重复性的催化剂是其在氧化脱硫过程中亟待解决的问题.     

多金属氧酸盐结构研究的新进展

当前,一大批结构新颖的多金属氧酸盐被合成出来,这些化合物大致可分为以下四类:(1)高核轮簇状多金属氧酸盐;(2)充当模板剂的多金属氧酸盐;(3)以多金属氧酸盐为建筑块的高维孔状的有机-无机杂化材料;(4)仿生化的多金属氧酸盐。     

SiW11/介孔TiO2杂化材料的制备与表征

将缺位Keggin结构多金属氧酸盐SiW11共价键联于介孔二氧化钛分子筛表面上,制备了SiW11/介孔TiO2杂化材料。用红外、低温N2吸附、TEM等对样品进行了表征。结果表明,键联于介孔TiO2表面的多金属氧酸盐SiW11保留完整的Keggin结构。较介孔二氧化钛相比,杂化样品的比表面积和孔容均有所减少。     

多金属氧酸盐基稀土金属簇合物在癌症诊断和治疗中的潜在应用

近年来,多金属氧酸盐（POMs）被认为是有前途的抗癌药物,因其具有氧化还原性、亲核性、高溶解性和稳定性,以及表面电荷分布和可调的分子结构,在抗癌领域呈现出广泛的应用前景.稀土（RE）金属簇合物具有丰富的光、电、磁等特性,利用POMs的结构特性作为无机氧-供体配体构筑丰富的多金属氧酸盐基稀土金属簇合物,将两者的优势进行整合,为癌症诊断和治疗领域提供了新思路.文章介绍了多金属氧酸盐基稀土金属簇合物的分类及其在癌症诊断和治疗中的潜在应用.     

多金属氧酸盐基的化合物修饰电极研究进展

对多金属氧酸盐基的各类化合物修饰电极的研究近况进行了综述，分别介绍了多金属氧酸盐基的化合物修饰电极的制备方法及其电催化研究情况，并对其发展方向进行了展望。     

基于Keggin型多金属氧酸盐的有机-无机杂化材料的研究进展

当前,一大批结构新颖的基于Keggin结构的有机一无机杂化化合物被合成出来,这些化合物大致可分为以下四类:(1)帽式多金属氧酸盐;(2)支撑型多金属氧酸盐;(3)多金属氧酸盐的有机金属化合物;(4)以Keggin为建筑单元的扩展结构.     

有限长金属纳米线调控纳米线波导的传输特性研究

基于有限元方法,通过改变有限长金属纳米线的长度、半径、介质有效折射率以及有限长金属纳米线和波导之间的距离,研究了有限长金属纳米线对纳米线波导传输特性的调控效果。结果表明:沿有限长金属纳米线长度方向,表面等离极化激元在两金属纳米线耦合区域内形成共振。随着有限长金属纳米线长度的增加,透射率逐渐减小,并呈周期性变化。随着金属纳米线半径和介质衬底有效折射率的增大,复合波导的透射率均相应增大。透射率与两根纳米线间距紧密相关,当金属纳米线取不同半径值,两根纳米线间距为20nm左右时透射率均达到最小值;当两根金属纳米线间距较大时,透射率不再明显变化。     

多金属氧酸盐对聚乙烯醇在水中溶胀性能的影响

制备了含不同结构多金属氧酸盐(HPA)和含量不同多金属氧酸盐的聚乙烯醇(PVA)纤维材料,并用IR、XRD光谱和扫描电镜(SEM)对其进行了表征.针对PVA在水中的溶胀性能,系统地研究了多金属氧酸盐的种类、含量、交联温度和时间对PVA纤维材料的水溶性的影响.     

多金属氧酸盐抗肿瘤研究进展

 多金属氧酸盐以显著的抗肿瘤、抗病毒和抗菌等药物活性在药物化学领域引起广泛关注。利用其独特的结构可修饰性特点,可引入不同种类有机或无机基团,合成多种功能性化合物。研究人员对于合成高效低毒的多金属氧酸盐药物,阐明其药物作用机制做出了大量的研究工作。本文概述了近年来有机或有机金属多金属氧酸盐衍生物的抗肿瘤研究,重点阐述了多金属氧酸盐的抗肿瘤机制及生物学效应,包括氧化还原理论、核酸降解、诱导凋亡、诱导自噬性死亡、以及对机体免疫的影响,并展望了多金属氧酸盐抗肿瘤研究的发展方向。     

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