双马来酰亚胺树脂的改性研究

合成和分析了双马来酰亚胺和3，3′-二烯丙基-4，4′-二羟基二苯丙烷，并由它们为原料制备了双马来酰亚胺改性树脂。用IR和DSC技术检测了树脂的固化反应；还对树脂的性能进行了表征。结果表明，改性的树脂还溶于低沸点极性溶剂；固化温度大于160℃；热分解温度达424℃；玻璃化转变温度340℃左右，是一种兼有优良工艺性能和耐热性的热固性树脂。     

纳米TiO2材料的合成与特性

用溶胶一凝胶法制得了纳米晶的ＴｉＯ２粉未，采用热分析、Ｘ射线、透射电镜及红外吸收光谱技术研究了材料的结构及尺寸形貌在不同热处理温度下的变化规律．结果表明：ＴｉＯ２干凝胶粉未在３５０℃热处理后晶态锐钛矿结构开始形成，而粉末的粒径增长缓慢；ＴＥＭ显示平均颗粒大小为２２ｎｍ．当热处理温度高于５５０℃时，ＴｉＯ２晶粒迅速长大，并出现金红石结构的ＴｉＯ２到７５０℃时，样品中所有的晶粒均转变为金红石结构．     

苯酚型硼氮配位酚醛树脂的热性能与热降解动力学

用多聚甲醛法合成了苯酚型硼氮配位酚醛树脂,1H NMR和FTIR证明了其结构,用动态力学谱仪测定了玻璃化转变温度(Tg)与固化程度的关系,用热重法(TGA)分析了硼氮配位酚醛树脂的热分解动力学.结果表明树脂的玻璃化转变温度超过200℃,并随固化反应程度增加而提高,热分解过程为多阶段分解,且均符合一级动力学,热分解活化能随分解程度提高而增加.     

TiO2纳米薄膜和TiO2／ZnFe2O4纳米复合薄膜的光学性能研究

用磁控溅射方法制备了ＴｉＯ２ 纳米薄膜和ＴｉＯ２／ＺｎＦｅ２Ｏ４ 纳米复合薄膜,研究了不同温度热处理和不同含量纳米铁酸锌对纳米ＴｉＯ２ 薄膜光学性能的影响。研究结果表明：用磁控溅射方法制备的纳米薄膜的厚度和晶粒尺寸均匀,并且随着热处理温度的升高而增大,掺杂纳米ＺｎＦｅ２ Ｏ４后ＴｉＯ２ 纳米薄膜的晶粒尺寸略有减小。ＸＲＤ 研究发现ＴｉＯ２／ＺｎＦｅ２Ｏ４ 纳米复合薄膜由非晶相向锐态矿相转变的温度高于纳米ＴｉＯ２ 薄膜。ＴｉＯ２ 纳米薄膜和ＴｉＯ２／ＺｎＦｅ２ Ｏ４ 纳米复合薄膜的光吸收边都随着晶粒尺寸的降低而发生蓝移,在相同热处理条件下,掺杂纳米ＺｎＦｅ２ Ｏ４ 后,纳米ＴｉＯ２薄膜的光吸收边发生了较大范围的红移,红移量随着掺杂量的增加而增大。通过热处理和掺杂纳米ＺｎＦｅ２Ｏ４ 可以实现对纳米ＴｉＯ２ 薄膜光吸收边大范围的调制。     

高温气溶胶反应器中制备纳米TiO2颗粒的形态和结构

在高温管式气溶胶反应中,利用ＴｉＣｌ４,气相氧化制备纳米ＴｉＯ２颗粒,研究了ＴｉＯ２颗粒的形态和结构特征,实验结果表明氧气预热温度升高,ＴｉＯ２粒子粒径减小,分布变窄,反应气氛中加入ＡｌＣｌ３后ＴｉＯ２粒变得圆整,ＴｉＯ２粒径随ＡｌＣｌ３用量增加而减小,粒子中金红石含量随ＡｌＣｌ３用量增加而增大,反应温度升高时ＴｉＯ２粒子粒度增大,但金红石含量在反应温度为１２００℃时出现最大值,控制反应温度为１１     

丙烯酸氨基甲酸酯树脂热性能的研究

用测定在不同升温速率下ＴＤＩ／ＰＰＧ（２０００）／ＨＥＡ体系ＵＡ齐聚物固化物热失重曲线的方法研究了ＵＡ树脂固化物的热分解动力学，测定了分解活化能，讨论了ＵＡ树脂固化物在氮气气氛中程序升温时的分解反应，用ＴＧ和ＤＴＡ方法研究ＵＡ和ＵＭＡ树脂固化物的热稳定性表明，ＵＭＡ比ＵＡ树脂固化物的起始分解温度高，加入稀释剂（ＭＭＡ或ＥＧＤＭ）可提高ＵＡ树脂固化物的热稳定性。     

纳米ZrO2—TiO2复合氧化物微粉的制备研究

研究了用水热法制备纳米ＺｒＯ２－ＴｉＯ２复合氧化物微粉。制备了ＺｒＯ２（Ｃ）－ＴｉＯ２（Ａ）。ＺｒＯ２（Ｃ）－ＴｉＯ２（Ｒ）,ＺｒＯ２（Ｔ）－ＴｉＯ２（Ａ）,ＺｒＯ２（Ｔ）－ＴｉＯ２（Ｒ）四组纳米复合氧化物及无定形的复合Ｚｒ－Ｔｉ水合氧化物。研究了它们的相变和可烧结性。经１４００℃烧结１０ｈ得到了具有９５％理论密度的ＺｒＴｉＯ４陶瓷。     

稀释剂Al_2O_3对Al/TiO_2自蔓延高温合成反应影响的研究

在研究稀释剂Ａｌ＿２Ｏ＿３对自蔓延高温合成反应４Ａｌ＋３ＴｉＯ＿２＝３Ｔｉ＋２Ａｌ＿２Ｏ＿３的绝热温度及反应模式的影响的基础上，研究了稀释剂Ａｌ＿２Ｏ＿３对该ＳＨＳ反应过程的影响以及对合成Ｔｉ／Ａｌ＿２Ｏ＿３金属陶瓷复合材料组织结构的影响．结果表明，稀释剂Ａｌ＿２Ｏ＿３含量增加，ＳＨＳ反应所必需的预热温度提高，燃烧速率降低，且燃烧不稳定；制备的Ｔｉ／Ａｌ＿２Ｏ＿３金属陶瓷复合材料致密度下降，但产生裂纹的倾向减少．     

光化学反应制备纳米TiO2微胶粒及其性能

讨论了通过光化学反应在水介质中由Ｔｉ＾３＋离子制备纳米ＴｉＯ２微胶粒（１５￣２５ｎｍ）的实验方法;研究了光化学反应条件（温度、浓度、酸度等）对反应速率的影响;探讨了纳米ＴｉＯ２微胶粒的量子尺寸效应、电性及聚沉、稳定存在条件及光催化活性等性能,为研制超细ＴｉＯ２微胶粒子提供了实验方法和理论依据。     

含羟基马来酰亚胺固化邻甲酚醛环氧树脂

合成N-对羟基苯基马来酰亚胺,并将其用作固化剂固化邻甲酚醛环氧树脂.采用DSC方法研究了HPM固化邻甲酚醛环氧树脂反应的固化反应动力学.对固化产物的热分析结果表明:N-对羟基苯基马来酰亚胺是非常良好的耐热固化剂,可明显提高邻甲酚醛环氧树脂的耐热性能,固化产物的起始热分解温度为338℃,分解10%时的温度为386℃,700℃时的残留百分量为49%.     

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