基于环形电磁矩超材料的可调谐太赫兹吸收器

本文提出一种反向开口双金属谐振环超材料集成微流通道的可调谐太赫兹波吸收器.数值分析了超材料环形电磁矩的高效激发,讨论了环形电磁矩的共振吸收谱对微流介质层的介电参数与磁参数调控的响应.采用可电控液晶材料注入微流通道的方案,通过太赫兹透明电极施加外部电场控制液晶折射率变化,实现太赫兹超材料吸收器工作频率的大范围动态调谐.频率移动量超过100%的共振带宽,相对调谐量(Δf/f)可高达15%,频率调谐呈现良好的线性操作特征和近100%吸收率的完美吸收性能.所提出的可调谐太赫兹吸收器在太赫兹探测和微流生化传感领域具有广阔的应用前景.     

石墨烯微米带THz SPPs的激发及场分布特性研究

表面等离激元可以突破衍射极限,具有强局域性,在传感、起偏、吸收、分束等方面具有广泛的应用前景.目前,太赫兹波段的表面等离激元器件研究大多是在远场光谱方面,其近场特性的研究有待更进一步深入.本文基于石墨烯微米带结构,研究了太赫兹表面等离激元的激发及场分布特性.本文设计了能够通过太赫兹波激发表面等离激元的石墨烯微米带结构,数值计算了其表面等离激元的场分布,并制备了石墨烯微米带器件,利用透射式太赫兹近场显微镜激发并测量了石墨烯微米带的表面等离激元,对共振失谐对等离激元场分布的影响进行了探究.研究结果为石墨烯表面等离激元器件在太赫兹生物传感、安全检测、高数据率通信等方面的应用提供了相关指导.     

由介电函数探讨SERS效应的电磁增强机理

从能够产生表面增强拉曼散射 (SERS)效应的典型金属银出发 ,讨论其在光频段的介电函数及与此介电函数相关的表面等离子体共振现象 ,进而用表面等离子体共振理论讨论SERS效应的电磁增强机理 .     

基于局域表面等离子体共振特性的高灵敏度凝血酶检测

用核酸适体修饰的纳米金共振散射光谱探针可实现对微纳空间内凝血酶的特异性识别与检测.提出了一种基于局域表面等离子体共振-暗场显微光谱联用技术的分析方法,研究了局域在金纳米粒子表面的生物分子的识别过程对局域表面等离子体共振散射光谱的影响.研究了单颗粒纳米粒子的形貌特征,实现了单分子层面上生物分子识别过程的追踪.     

电磁超材料吸收器在太赫兹波段的研究进展

基于电磁超材料的太赫兹吸收器通过合理设计结构尺寸和材料参数能够实现近完美吸收,因而受到学术界的关注,近几年对太赫兹吸收器的研究发展很快.本文综述了基于电磁超材料的太赫兹吸收器的研究进展,分别从理论、结构和性能对太赫兹吸收器的研究进行了介绍,最后对太赫兹吸收器的未来发展和待解决的问题进行了探讨.     

基于石墨烯超材料的类电磁诱导透明研究

建立一个基于石墨烯的太赫兹超材料的周期单元结构,利用时域有限差分法进行仿真计算,深入解析石墨烯超材料与太赫兹电磁波相互作用出现的电磁诱导透明现象。分析了TM模式下该结构的电磁诱导透明发生的机理,通过改变结构材料、入射角度、石墨烯条的尺寸,分析反射峰的频点和透明窗口变化。计算结果表明:该结构在5.59 THz处由于共振耦合产生干涉相消,形成一个透明窗口;当石墨烯条的宽度增加时,共振频点发生蓝移,共振强度也明显增强,但透明窗口宽度并没有明显的变化;增加电磁波的入射角度,共振耦合强度减弱,但耦合频点基本无变化,说明该结构产生的电磁诱导透明效应对电磁波入射角不敏感。该研究结果在太赫兹反射器、非线性器件等方面有着潜在的应用价值,给太赫兹超材料器件的设计提供了新的思路。     

多层电磁超材料在太赫兹技术中的应用研究进展

基于电磁超材料的电磁谐振通过合理设计可以实现太赫兹波段的频率响应,为太赫兹波调控开辟了新的道路,特别是利用多层电磁超材料设计的太赫兹功能器件.本文综述了当前国内外基于多层电磁超材料在太赫兹波段技术的应用研究进展,分类介绍了其在太赫兹滤波器、吸收器、偏振器等方面的应用,最后对多层超材料在太赫兹技术应用的发展趋势作了探讨.     

表面等离子体共振免疫传感的放大检测研究

表面等离子体共振免疫传感器是一类相对新型的免疫检测技术。将链霉亲和素-生物素系统用于表面等离子体共振免疫传感的信号放大,实时检测了人免疫球蛋白G(hIgG)的蛋白浓度。发生免疫反应的传感片和生物素化抗体反应后,传感片表面的一层生物素分子随后与链霉亲和素-生物素化抗体复合物中的链霉亲和素的活性位点发生亲和反应,从而使传感片表面特异健合的物质质量显著增加,大大提高了免疫检测的灵敏度和检测限。免疫反应经放大后,可检测0.005～10μg/mL浓度区间内的hIgG。     

多层聚合物膜系高灵敏度表面等离子体共振传感理论研究

基于光学Kretschmann棱镜结构,建立了表面等离子体共振(SPR)传感器模型并进行了模拟计算,得到了基于聚乙烯和聚丙烯酸的多层膜系的SPR传感器共振光谱中共振波长随共振角度的演化.模拟分析表明,聚合物的厚度增加导致共振峰的红移,最佳厚度为100nm左右;聚合物薄膜可实现SPR共振峰的可控的红移和传感检测,聚乙烯相对于聚丙烯酸有较高分辨率;金纳米颗粒具有增强表面等离子体共振信号的作用,共振波长因其填充因子的增大而发生红移现象,半峰宽明显变宽,填充因子最佳值为0.2.     

基于亚波长金属耦合腔光栅的太赫兹传感器

提出一种亚波长金属耦合腔光栅结构的太赫兹传感器。采用亚波长矩形腔结构单元,设计了谐振腔级联耦合的金属亚波长光栅。利用谐振腔与光栅导模共振的相干耦合作用,产生高品质因数的类电磁诱导透明模,形成腔诱导太赫兹波异常反射现象。异常反射模表现出显著的局域场共振增强效应,大大提升太赫兹波对分析物的感测能力。数值仿真表明,太赫兹波正入射的传感灵敏度可达到6-22THz/RIU,品质优值可高达55-152,同时具有宽达50°工作角的太赫兹感测能力,可适应大孔径角太赫兹波束的传感操作。     

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