聚丙烯酸酯/TiO2纳米复合乳液的研究

以丙烯酸酯为原料、纳米TiO2粉体或浆料作为改性剂，采用不同改性工艺，制备丙烯酸酯／TiO2纳米复舍乳液，研究各种因素(反应温度、原料组成、配比和其它添加剂)对乳液性能的影响。结果表明：以油酸作为纳米粉体TiO2的表面改性剂，可明显改善复合乳液的各种性能；各种改性方法中，表面改性效果最佳；表面改性剂(油酸)的用量为(0．15—0．25)％时，复合乳液及其涂膜的性能最佳；表面改性的纳米粉体TiO2对复合乳液的改性效果优于直接用纳米浆料混合所得的纳米复合乳液。     

KH-550改性纳米二氧化硅的研究

用硅烷偶联剂KH-550对纳米SiO2样品表面进行改性,测定了改性SiO2样品的亲油化度,并用羟基紫外线吸收法测试了改性效果,对所得纳米SiO2样品的改性效果进行了评价,探讨了纳米级SiO2的改性机理.结果表明,改性剂用量、改性温度、改性时间明显地影响改性效果.通过对改性工艺条件的合理调控,实现了用硅烷偶联剂KH-550改性纳米SiO2样品,找到了合适的改性工艺与条件,所得改性纳米SiO2样品具有较高的疏水性.     

抗菌纳米ZnO复合乳液的制备及抑菌效果

选用丙烯酸丁酯、苯乙烯等单体，对钛酸酯偶联剂改性的抗菌纳米氧化锌进行原位聚合，制备具有核壳结构的纳米ZnO复合乳液；以水溶性羧甲基纤维素钠（CMC—Na）为分散剂，制备纳米ZnO／苯丙共混复合乳液。采用活化指数、亲油化度以及红外光谱评价纳米ZnO的表面改性效果，井对复合乳液的粒径、抑菌性及紫外线屏蔽效应作了系统研究。结果表明，当偶联剂用量为纳米ZnO量的1／10时，改性纳米ZnO的活化指数、亲油化度均达最大；当pH为5—6，CMC—Na用量为3％，改性纳米ZnO的分散效果最好。当改性纳米ZnO含量为0．1％-0．4％，复合乳液具有优良的抑菌作用和紫外线屏蔽功能。     

乙酰丙酮铁配合物对纳米二氧化钛表面改性

通过吸附法用乙酰丙酮铁配合物对纳米TiO2进行表面改性,以光催化降解甲基橙为探针反应,在紫外光照条件下考察了配合物含量、吸附温度、溶剂用量、吸附时间等改性条件对纳米TiO2催化活性的影响。研究表明,用乙酰丙酮铁改性纳米TiO2非常有效。当w[Fe（acac）3/TiO2]为0．25％,吸附温度为60℃,溶剂用量为乙醇／TiO2等于29mL·g^-1,吸附1．5h时,改性后的纳米TiO2催化活性比改性前有了很大的提高。即使在普通白炽灯光照条件下,改性催化剂仍然显示出很高的光催化活性,明显优于非改性的纯TiO2。改性纳米TiO2经过IR、XRD、UV—Vis、荧光分析表征。     

纳米材料改性新型钢结构防火涂料的研究

研究采用纳米材料改性钢结构防火涂料，实验表明：采用经硅烷偶联剂改性的纳米粒子改性钢结构防火涂料，可解决无机纳米粒子在有机涂料中的分散问题，从而可有效地提高钢结构防火涂料的耐火极限；实验还表明，不同的纳米材料及其加入量对钢结构防火涂料的耐火极限均有不同程度的影响。在最常用纳米TiO2、纳米SiO2和纳米B2O3这几种纳米材料中，纳米TiO2的效果最好，经其改性后的防火涂料的耐火极限可提高6min，防水性可提高17．9％；当纳米TiO2含量为0．9％时，改性效果为最佳。     

纳米氧化镁制备和表面改性研究

以MgCl2.6H2O和NH3.H2O为原料,乙醇和吐温80为分散剂,采用均匀沉淀法制备氢氧化镁,经水洗、醇洗、干燥、煅烧得到纳米氧化镁粉体。实验确定制备纳米氧化镁的工艺条件为:反应配比MgCl2.6H2O∶NH3.H2O(摩尔比)为1∶2,反应温度45℃,反应时间40 min,陈化时间2 h,氢氧化镁在900℃下煅烧3 h。以亲油化度为考察指标,通过单因子实验和正交实验,确定了纳米氧化镁表面改性的最佳工艺条件为:硬脂酸0.02 g,改性温度80℃,改性时间2 h.在优化条件下,改性后的纳米氧化镁的亲油化度达到27.7%.用透射电镜(TEM)对改性前后的纳米氧化镁粉体进行了表征,TEM表明所制备的样品为纳米级,改性前后氧化镁粒子尺寸基本没有变化,但改性后的纳米氧化镁分散性明显变好.     

纳米ZnO的表面改性研究

研究了纳米ZnO表面改性的影响因素，确定了最优改性剂和改性条件。通过正交实验以月桂酸钠为改性剂、用量为15％、pH值为6、改性时间为1．5h时，改性后的纳米ZnO的亲油化度达到79．2%，能较好地分散于甲醇和二甲苯中。     

亚微米级无机抗菌剂的有机湿法改性

采用硬脂酸与钛酸酯偶联剂联用对超细亚微米级载银TiO2进行了表面改性，使表面由亲水性变为亲油性，并探讨了改性前后的表面结构。用IR、TEM等多种手段表征其改性效果，用X射线荧光光谱测定了改性对银离子含量的影响。结果发现硬脂酸和钛酸酯成功包覆在粉体表面，包覆量可达0.92%，使粉体表面性质由亲水变为亲油；但用振荡烧瓶法测定改性前后抗菌剂对大肠杆菌的抗菌率，仍然达到99.7%。     

掺杂与涂膜纳米TiO2光催化性能的研究

分别对掺杂纳米TiO2和分子筛负载纳米TiO2的光催化性能进行了对比研究，并对负载纳米TiO2进行了SEM检测。通过正交实验设计对其降解甲基橙溶液作了进一步研究，找出其最佳处理条件为：催化剂用量7．5g／L；光照时间1．5h；pH＝3。     

一种新型高耐磨性紫外光固化路标涂料的研制

选用纳米TiO2作为填料,经表面亲油改性,采用活性单体交联和紫外光固化,制备了一种新型高耐磨性路标涂料.讨论了TiO2、光引发剂、活性单体用量及种类对涂料耐磨性的影响.结果表明:较适宜的添加量为:纳米TiO2用量为12%(W);活性单体为双官能度且用量10%;光引发剂用量为6%.     

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