Co/Si多层膜的磁控溅射及其X射线衍射分析

用超高真空磁控溅射设备在不同溅射压强及衬底温度的工艺条件下制备了一系列Ｃｏ／Ｓｉ多层膜．Ｘ射线小角衍射证实所研制的多层膜具有周期调制结构．分别采用不同的理论方法计算了多层膜的周期和折射修正项．表明修正项不再仅对折射效应修正,而应理解为更广义的修正项．并应用广义修正总多层膜厚度Ｂｒａｇｇ公式确定出了主峰之间次峰的级数．     

静高压在多层Al／Fe—Mo—Si—B纳米合金复合材料…

在３￣５．５ＧＰａ的压力范围内，经过８７３Ｋ，３０ｍｉｎｈ等温热处理由非（Ｆｅ０．９９Ｍｏ０．０１）７８Ｓｉ９Ｂ１３（ＦＭＳＢ）条带和纯金属Ａｌ片交替叠成的样品，制备出多层Ａｌ／Ｆｅ－Ｍｏ－Ｓｉ－Ｂ纳米合金复合材料。研究了静高压在复合材料制备中影响非晶ＦＭＳＢ合金晶化相，Ｆｅ－Ｍｏ－Ｓｉ－Ｂ纳米合金晶粒度和Ａｌ／Ｆｅ－Ｍｏ－Ｓｉ－Ｂ复合材料界面相的规律及机制。     

射频溅射制备α－Ge／SiO2多层膜

射频溅射制备α－Ｇｅ／ＳｉＯ２多层膜崔敬忠彭军张兴旺陈光华张仿清（兰州大学物理系，兰州７３００００）由于在非晶太阳能电池和半导体器件方面的重要性，α－Ｇｅ和α－ＳｉＯ２得到了深入的研究［１，２］．近年来，用共溅射的方法制备的Ｇｅ／ＳｉＯ２纳米材料由...     

巨磁热效应材料Gd5SixGe4-x三元合金的制备及晶体结构

三元合金Ｇｄ５ＳｉＧｅ４－ｘ是一种具有巨磁热效应的材料。作者用熔炼法在氩气气氛中合成了四种Ｇｄ５ＳｉｘＧｅ４－ｘ样品（其中ｘ＝４,３．２,２．１６,２）。粉末Ｘ射线衍射结果表明,当４≥ｘ〉２时Ｇｄ５ＳｉｘＧｅ４－ｘ为正交晶体;当ｘ＝２时Ｇｄ５Ｓｉ２Ｇｅ２畸变成单斜晶体。随着Ｇｅ量的增加,晶胞参数及单胞体积都随之增加。同时还测定了均质化处理对这些合金的作用。     

FeSi／Cu多层膜的磁性和磁光效应

用射频交流溅射法制备了具有不同层厚的ＦｅＳｉ／Ｃｕ多层膜系列样品。通过铁磁共振谱测量发现：当Ｃｕ层厚度（ｄＣｕ）小于１５Ａ时，ＦｅＳｉ层间发生交换耦合。室温饱和磁化强度测量发现：ｄＣｕ＜１５Ａ，磁化强度随ｄＣｕ减小而明显下降。磁光克尔谱测量则表明：ｄＣｕ＜１５Ａ时，谱线出现异常。将上述三个结果进行综合分析提出如下模型：ｄＣｕ＜１５Ａ，Ｃｕ层中传导电子被反向极化，并通过ＲＫＫＹ相互作用使ＦｅＳｉ层间     

SiC／W纳米多层膜的微结构和微观力学性能

用磁控溅射法在硅基底上制备了不同调制波长Λ的ＳｉＣ／Ｗ纳米多层膜,利用小角度衍射技术（ＬＸＤ）研究了各样品子层界面的调制周期性,并用上限为２０ｍＮ的超显微硬度计ＵＭＨＴ－３,对上述纳米薄膜进行了多载荷微观力学性能测试．结果表明：纳米ＳｉＣ／Ｗ调制多层膜的超显微硬度随测试负荷Ｆ和调制波长Λ的改变而变化,在负荷为５ｍＮ时峰值硬度为１９．９ＧＰａ,与均匀混合的纳米薄膜相比,超显微硬度值提高了约１倍,显示出明显的硬度异常效应．结合实验结果对硬度值随调制波长Λ出现的峰值效应作了初步探讨．     

Si1-x-yGexCy合金薄膜电学性能的研究

采用射频共溅射复合靶（Ｓｉ＋Ｇｅ＋石墨Ｃ）技术制备Ｓｉ１－ｘ－ｙＧｅｘＣｙ三元合金薄膜,Ｓｉ,Ｇｅ和Ｃ的含量用其靶的相对面积来表示,对样品的后退火处理是在Ｎ２气保护下恒温３０ｍｉｎ后自然降温到室温。通过ＩＲ,Ｒａｍａｎ的ＸＰＳ的测量结果表明,所制备的薄膜中含有Ｓｉ,Ｇｅ,Ｃ３种元素,有较明显的Ｓｉ－Ｃ,Ｓｉ－Ｇｅ,Ｇｅ－Ｃ键合。通过电阻率－温度谱ρ－Ｔ的测量研究薄膜的电学性能,测量了不同Ｃ含量和不     

用MTGA法研究非晶合金的纳米晶化过程

用ＭＴＧＡ测量ＦｅＣｕＮｂＳｉＢ非晶样品的表观失重与温度关系σ－Ｔ和ｄσ／ｄＴ－Ｔ,发现非晶合金晶化过程可区分为５个不同阶段．研究经７５３～８８３℃等温退火１ｈ的样品发现,Ｔａ升高,析出的磁纳米晶体αＦｅＳｉ量增多,剩余非晶相的居里温度也升高．ＴＣ＝０．５２Ｔａ＋３６４．８,相关系数ｒ＝０．９８．用ＭＴＧＡ法测量αＦｅＳｉ或剩余非晶相的体积百分数随退火温度的变化     

P-GeSi/P-Si探测器的研制

采用ＭＢＥ法在Ｓｉ衬底上生长ＧｅＳｉ异质结,制成ＧｅＳｉ／Ｓｉ异质结探测器。测得其反向击穿电压为１５Ｖ左右,光响应为０．５ｍＡ     

Ge,Si的形变势及其应变层异质结的带阶

采用从头赝势能带计算方法研究了（００１）界面应变对Ｇｅ、Ｓｉ能带结构、平均键能和带阶参数的影响．计算了相应的形变势，并利用形变势的研究结果，采用平均键能方法计算了Ｇｅ／Ｓｉ应变层异质结在不同生长厚度ｈ（或平行晶格常数ａ∥）情况下的价带带阶和导带带阶．     

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.     

Wuhan University Journal of Natural Sciences TOTAL CONTENTS

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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.     

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     

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.     

英文诗歌中的喻类修辞

为了有助于提高英文爱好者的个人情操、文化素养和学习兴趣,以及专业人员对英语学习和研究进行多途径的探索,本文通过一些精选诗歌的引证和分析,着重论述了喻类修辞法在英文诗歌中的运用其及效果。     

Man Is Unable to Change the Miserable Life——Analysis of the Arrangement of Four Characters in The Glass Menagerie

Tennessee Williams is considered as one of the most important American playwrights since World War II.The Glass Menagerie is his first successful drama,which describes a tragic situation of family and means to say that Man is unable to change the miserable life,no matter whatever means he try,This essay focuses on the analysis of the arrangement of the four main characters:Laura.Amanda,Jim and Tom to reveal the theme.Laura is fragile.Amanda is brave.Jim is vital.Tom is sensible.And all of them develop and try the different means to struggle against life,but fail tragically.With the evidence,the paper comes to conclusion naturally that Man is unable to change the miserable life,and he dooms to fail.     

Characterization of root-nodulating bacteria on Retama raetam in arid Tunisian soils

The aim of this study is to investigate the diversity of Retama raetam root-nodule bacteria isolated from arid regions of Tunisia. Twelve isolates, chosen as representative for different 16S rRNA gene patterns, were characterized by 16S rRNA gene sequencing and phenotypic analysis. Isolates were assigned to Sinorhizobium, Rhizobium and Agrobacterium. Symbiotic properties of Sinorhizobium and Rhizobium isolates showed a large diversity in their capacity to infect their host plant and fix atmospheric nitrogen. Strain RK 22 identified as Rhizobium was the most effective isolate.     

Features of Women''s language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

An Affordable Accurate Evaluation of the Binding Conformations Predicted by Molecular Docking Studies in Bio-System

正Recently,docking has been widely used to predict the binding-modes of protein-inhibitors,when the crystal complexes structure was absent.Most docking algorithms are able to generate a large number of probable conformations,it,however,is difficult to effectively evaluate these docking poses and identify the most reasonable bindingmode.In the present study,on the basis of the crystallographic data of human 3-hydroxy-3-methylglutaryl coenzyme