形变硬化指数与强度的关系

从硬化指数的定义出发导出了形变硬化指数ｎ与强度参量之间的关系为ｎ＝Ａ（１－σⅠ－／σⅡ）＋Ｂ，σⅠ和σⅡ为真应力应变曲线上一直线段两端点的应用力，Ａ和Ｂ为常数，它适用于单一ｎ值情况，双ｎ特性，单调加载和循环应力应弯曲线，对均匀变形阶段，又导出了ｎ和屈强比的关系，即ｎ＝１－√σｓ／σｂ，该式没有任何特定常数和经验常数，和测量值相比９０％以上的数据的绝对误差在±０．０３以内，它表示了材料的均匀变形能力     

一类约束下的参数估计问题

考虑线性模型ｙｎ×１＝Ｘｍ×ｐβｐ×１＋εｎ×１，（１）其中ｙｎ×１为样本观测值，Ｘ为ｎ×ｐ阶的设计阵，β为ｐ维参数向量，εｎ×１为ｎ维随机向量，ε为随机误差．Ｅε＝０，Ｄε＝σ２Ｖ这里σ２已知或未知皆可，Ｖ为ｎ×ｎ阶非负定阵．对于线性模型（１），...     

线性结构关系模型参数估计的强收敛速度

该文讨论了线性结构关系模型｛β’ｘｋ＋α＝０ ζｋ＝ｘｋ＋εｋ ｛εｋ，ｋ＝１，２，…，ｎ｝，ｉ，ｉ，ｄ。ｋ＝１，２，…，ｎ，Ｅ（ε１）＝０ ｖａｒ（ε１）＝σ＾２Ｉｍ式中，｛ｘｋ，ｋ＝１，２，…，ｎ｝为一组ｉ．ｉ．ｄ。的不可观测的ｍ维随机向量，｛ｘｋ，ｋ＝１，２，…，｝，与｛εｋ，１，２，…，ｎ｝相互独立。     

半线性椭圆方程Δu—a（x）u＋b（x）u^p=0 Dirichlet问题的奇异解

证明了半线性椭圆方程Δｕ－ａ（ｘ）ｕ＋ｂ（ｘ）ｕ＾ｐ＝０的Ｄｉｒｉｃｈｌｅｔ问题，当１〉ｐ〉（ｎ＋２）／（ｎ－２），ｎ≥３，且ａ（│ｘ│），ｂ（│ｘ│）满足适当条件时有无穷多奇异正解。     

一种新型的拉伸应力应变曲线规律研究

研究发现低层错能的亚稳材料低温拉伸存在一种新型的应力应变曲线．曲线表现为弹塑性失稳εｐｈ 、应力平台εＬ 及硬化指数ｎ 为不恒值的３ 个特点．试验结果表明：εｐｈ 、εＬ 随应变率增加而增大,硬化率ｄσ／ｄε与硬化指数ｎ 随应变量的增加呈抛物线型．弹塑性失稳及应力平台本质上不同于稳定态材料的上、下屈服及屈服平台,而是由相变引起的新的屈服机制,即弹塑性失稳是应变诱发马氏体转变的起始状态,应力平台是相变软件与硬化动态平衡的结果     

尖端效应的一种近似描述

以旋转抛物面模拟尖端，给出导体尖端效应的一种近似描述即电荷面密度σ与高斯曲率Ｋ的关系σ＝σο根号ｍＫ１／４，σο是尖端顶点σ的值，可通过测出该点法向线程Δｎ的电势差ΔＶ获得，σο＝εＥ≈２εＨοΔＶ／〔ｅｘｐ（－２ＨοΔｎ）－１〕．σ分布的这一关系为其工程测量提供了依据。     

复合图Ga（u）⊙UV⊙G2（V）的niche数

复合图Ｇ１（ｕ）⊙ｕｖ⊙Ｇ２（ｖ）是将简单图Ｇ１的顶点ｕ与简单图Ｇ２的顶点ｖ用边ｕｖ连接成的图。本文证明，若Ｇ１和Ｇ２都是有限ｎｉｃｈｅ图，则当连接点ｕ，ｖ满足一定的条件时，复合图Ｇ１（ｕ）⊙ｕｖ⊙Ｇ２（ｖ）也是有限ｎｉｃｈｅ图，且ｎ（Ｇ１（ｕ）⊙ｕｖ⊙Ｇ２（ｖ）０≤ｎ９Ｇ１）＋ｎ（Ｇ２）－ｒ其中，ｒ＝０，１，２。     

关于frame SOLS存在性的进一步结果

已经证明对ｕ≥２，ＦＳＯＬＳ（３￣ｎｕ￣１）存在的充分必要条件是ｎ≥４且ｎ≥１＋２ｕ／３，除去可能的例外ｎ∈｛６，１０，１４，１５，１８，１９，２２，３０，３４，３８，４２，４６，５４，５８，６２，６６，７０，９４｝．本文证明除７２对（ｎ，ｕ）值外，ＦＳＯＬＳ（３￣ｎｕ￣１）存在的充分必要条件是ｎ≥４且ｎ≥１＋２ｕ／３．     

复合图G1(u)⊙uv⊙G2(v)的niche数

复合图Ｇ１（ｕ）⊙ｕｖ⊙Ｇ２（ｖ）是将简单图Ｇ１的顶点ｕ与简单图Ｇ２的顶点ｖ用边ｕｖ连接成的图．本文证明：若Ｇ１和Ｇ２都是有限ｎｉｃｈｅ图，则当连接点ｕ，ｖ满足一定的条件时，复合图Ｇ１（ｕ）⊙ｕｖ⊙Ｇ２（ｖ）也是有限ｎｉｃｈｅ图，且ｎ（Ｇ１（ｕ）⊙ｕｖ⊙Ｇ２（ｖ））≤ｎ（Ｇ１）＋ｎ（Ｇ２）－ｒ其中，ｒ＝０，１，２．     

一类电报方程解的Sobolev指数

对一般的偏微分方程,其Ｓｏｂｏｌｅｖ指数为（ｎ２＋１）,Ｐｏｎｃｅ和Ｓｉｄｅｒｉｓ（Ｃｏｍｍｕｎ．ｉｎＰＤＥ,１９９３,１８（２～４）：１６９）证明了对一些具特殊非线性项的半线性方程,如ｕｔ－Δｕ＝ｕｋ（Ｄｕ）α（ｘ∈Ｒｎ,ｋ∈Ｚ＋,ρ＝｜α｜≥２）,其Ｓｏｂｏｌｅｖ指数会在ｎ２与（ｎ２＋１）之间,本文研究半线性电报方程ｕｔ－Δｕ＋ｐｕ＝ｕｋ（Ｄｕ）α（ｘ∈Ｒｎ,ｋ∈Ｚ＋,ρ＝｜α｜≥２,ｐ≠０）,得到了其Ｓｏｂｏｌｅｖ指数仍然在区间（ｎ２,ｎ２＋１）之内,因此本文可以看作是Ｐｏｎｃｅ和Ｓｉｄｅｒｉｓ工作的继续     

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.     

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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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.     

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     

WIMAX与WI-FI技术分析及联合组网

介绍了WiMAX与Wi-Fi两种无线宽带接入技术,并对两者之间的关系及相互之间的影响做了对比及分析,并对WiMAX的关键技术进行了详细说明,最后对两者的联合组网方式做了简单的探讨。