改性木屑处理含Cr（VI）废水的研究

通过正交试验选择制备改性木屑的最佳条件，水解改性后的木屑能将Ｃｒ（Ⅵ）还原成Ｃｒ＾３＋，每克改性木屑对Ｃｒ（Ⅵ）的最大还原能力为４９０ｍｇ。将其装成柱子，让ρＣｒ（Ⅵ）＝ｍｇ／Ｌ及ｐＨ＝２的含Ｃｒ（Ⅵ）电镀废水通过柱子，其接触时间不小于６ｍｉｎ，Ｃｒ（Ⅵ）的还原率在９９．５％以上。     

水中痕量Cr(Ⅵ)的流动注射-分光光度测定

研究建立了测定水中痕量Ｃｒ（Ⅵ）的二苯基碳酰二肼（ＤＰＣ）－流动注射分光光度法,将含Ｃｒ（Ⅵ）水样注入到Ｈ２ＳＯ４溶液和ＤＰＣ溶液的混合流中,在λｍａｘ＝５４０ｎｍ处对反应形成的紫红色Ｃｒ（Ⅱ,Ⅲ）－二苯基偶氮碳酰肼蝥合物进行分光光度检测．线性范围为０．０３～１．６０ｍｇ／ＬＣｒ（Ⅵ）,检测限为０．０１４ｍｇ／Ｌ,测定频率为１００次／ｈ．本法灵敏度高、选择性好、分析速度快．用本法测定工业废水中痕量Ｃｒ（Ⅵ）,获得满意结果     

微量钒的停流流动注射－动力学光度法测定

依据Ｖ（Ⅳ）－Ｃｒ（Ⅵ）反应对Ｃｒ（Ⅵ）－Ⅰ－氧化还原反应的诱导，以淀粉络合物为指示剂建立了一种测定微量钒的停流－诱导动力学光度法．线性范围为０～１．８ｍｇ／Ｌ，方法检测限为０．００８ｍｇ／Ｌ．除Ｆｅ２＋、Ｓｂ３＋外，大部分共存离子不影响测定．测定了土样中钒含量，结果满意．     

5''''-硝基-水杨基荧光酮-氯代十六烷基吡啶荧光熄灭法测定痕量Cr(Ⅵ)

基于Ｃｒ（Ⅵ）－５′－硝基－水杨基荧光酮（５′－Ｎ－ＳＡＦ）－氯代十六烷基吡啶（ＣＰＣ）体系的荧光熄灭效应，提出一种测定痕量铬（Ⅵ）的新荧光分析方法．ｐＨ在４．５～５．５范围内的柠檬酸—氢氧化钠缓冲溶液中，在ＣＰＣ存在下，Ｃｒ（Ⅵ）与５′－Ｎ－ＳＡＦ形成摩尔比为１２的配合物，配合物的激发波长和发射波长分别为：λｅｘ１＝４７５ｎｍ，λｅｘ２＝５０５ｎｍ，λｅｍ＝５２５ｎｍ．Ｃｒ（Ⅵ）浓度在０．８～５０μｇ／Ｌ范围内与ΔＦ呈良好的线性关系，相关系数ｒ＝０．９９９２，检测限为０．８μｇ／Ｌ．本法灵敏度高，选择性好，适用于水样、人发中痕量Ｃｒ（Ⅵ）的直接测定     

褐煤腐植酸对Cr（Ⅵ）离子吸附物性试验

采用云南寻向褐煤撮提取的腐植酸对Ｃｒ（Ⅵ）溶液进行吸附性能试验，发现ｐＨ值在４～５范围时，该腐植酸对Ｃｒ（Ⅵ）的最大吸附量可达３５．３０ｍｇ／ｍ。     

Cr(Ⅵ)氧化5-溴水杨基荧光酮光度法测定微量Cr

在硫酸介质中,Ｃｒ（Ⅵ）将５－溴水杨基荧光酮（５－ＢＳＡＦ）氧化成最大吸收峰为４９４ｎｍ的有色产物,其表观摩尔吸光系数为３．６７×１０４Ｌ／（ｍｏｌ·ｃｍ）,Ｃｒ（Ⅵ）量在０～１５ｍｇ／２５Ｌ范围内服从比耳定律。用此法测定了电镀废液中微量Ｃｒ,回收率为９８．５％～１０３％,相对标准偏差为２．６％     

非晶态铬电镀溶液的电极过程

用Ｎｉ，Ｃｕ，Ｆｅ和玻璃碳电极，研究了非晶态铬电镀过程中Ｃｒ（－Ⅵ）还原为Ｃｒ（Ⅲ）的电化学特征，发现Ｃｒ（Ⅵ）还原为Ｃｒ（Ⅲ）的电势与电极材料密切相关，在金属电极上还存在着新相的形成和生长过程，新相形成主要是钝化膜中的铬离子还原为金属铬，这为后继的铬电沉积提供了晶体生长中心的过程。     

Cr（Ⅵ）的新富集剂──三聚氰酰胺甲醛树脂

天然水和工业废水中微量的铬Ｃｒ（Ⅵ）可以通过与三聚氰酰胺甲醛树脂的交换而被富集．本文研究了Ｃｒ（Ⅵ）的直接富集方法，并对Ｃｒ（Ⅵ）的富集能力、富集酸度、及回收率作了讨论．     

离子交换火焰原子吸收法测定水中Cr(Ⅲ)和Cr(Ⅵ)

研究了在ｐＨ＝２～３的条件下，用国产００１＃强酸性阳离子交换树脂、２０１×７＃强碱性阴离子交换树脂对水中Ｃｒ（Ⅲ）和Ｃｒ（Ⅵ）进行交换吸附，在Ｎａ２ＳＯ４存在下，用火焰原子吸收法直接测定交换后溶液中的Ｃｒ（Ⅵ）和Ｃｒ（Ⅲ）。方法简便易行，快速，特征质量为０．０７２μｇ／ｍＬ，相对标准偏差为２．７％，回收率为９５％～１０６％     

二安替比林基－（3，4－亚甲二氧基）－苯基甲烷光度法测定微量铬（Ⅵ）

合成了二安替比林基－（３，４－亚甲二氧基）苯基甲烷（ＤＡＤＭＰＭ）．研究了ＤＡＤＭＰＭ与Ｃｒ（Ⅵ）的显色反应．在Ｈ３ＰＯ４介质中，在Ｍｎ（Ⅱ）和吐温２０存在下，Ｃｒ（Ⅵ）与ＤＡＤＭＰＭ反应生成橙黄色产物，λｍａｘ为４７０ｕｍ，摩尔吸光系数ε＝３．０×１０５Ｌ·ｍｏｌ－１·ｃｍ－１．铬量在０—５μｇ／２５ｍｌ范围内符合比尔定律．已用于环境水样中Ｃｒ（Ⅵ）的测定，结果满意．     

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。