高分子絮凝剂及其应用研究进展

絮凝剂是一类可使液体中固体悬浮微粒凝聚、沉淀的物质.本文综述了高分子絮凝剂的研究现状,对高分子絮凝剂进行了分类并做了详细论述,并对无机絮凝剂、有机絮凝剂、淀粉絮凝剂、微生物絮凝剂和复合絮凝剂在废水处理等领域中的应用情况进行了综述.另外,对高分子絮凝剂的发展趋势做了分析和展望.     

基于聚硅酸硫酸铝锌絮凝剂对废水的处理效果分析

絮凝沉淀是目前应用最广的水处理方法之一,而废水处理药剂的性能则是絮凝处理效果好坏的关键因素。所谓絮凝剂,就是能使水溶液中的溶质、胶体或悬浮颗粒产生絮状物沉淀的物质。按照药剂使用化合物的类型,絮凝剂可分为无机絮凝剂、有机絮凝剂和生物絮凝剂。目前,新型无机高分子聚硅酸絮凝剂(PSAA)因其同时具有电中和及吸附架桥作用,絮凝效果好,克服了传统絮凝剂处理水样中残留铝含量高、稳定性差的缺点,具有较好的除浊、脱色、除油和除     

改性淀粉絮凝剂的制备及絮凝性能研究

以淀粉和丙烯酰胺为主要原料,采用反相乳液聚合方法制备淀粉接枝共聚物,考察了诸因素对反应过程的影响,并对产物絮凝性能进行了研究.结果显示:该絮凝剂能使污水中颗粒悬浮物絮凝成大颗粒沉淀,达到较好的絮凝效果.     

物化技术处理染料废水的研究进展

介绍了我国水资源的情况，指出了染料废水的水质特性；综述了絮凝沉降、吸附脱色、电解、纳滤膜、光催化技术在染料废水处理方面的应用，并对各方法的伏缺点做了说明；展望了物化技术处理染料废水的前景。     

海水养殖废水生物处理方法研究进展

我国是海水养殖业的大国,但养殖技术与模式和国际先进水平相比仍存在一定差距,环境污染问题严重,因此研究海水养殖废水处理技术十分必要。文章综述了国内外海水养殖废水生物处理方法中滴滤池、生物流化床、生物转盘、生物絮凝技术以及人工湿地技术研究现状和存在的问题。     

重金属废水处理技术研究进展(综述)

综述了重金属废水处理技术研究现状，介绍了微生物絮凝法、生物吸附法和植物整治技术的研究现状及应用前景，指出生物化学法处理重金属废水是一种长期、高效、经济、可靠的方法，     

焦化废水活性炭深度处理工艺的影响因素

焦化废水处理中COD及色度问题一直是困扰焦化企业环保达标的关键问题。确保焦化废水稳定达标处理以及经济高效运行,必须将废水生化处理与深度处理有效结合。生化处理出水采用活性炭脱色+絮凝沉降工艺是保障焦化废水出水稳定达标运行的有效方式,解决影响活性炭吸附脱色加絮凝沉淀工艺的有害因素是确保废水处理高效经济运行的必要条件。     

不同pH值条件下天然高分子絮凝剂处理废水的效果研究

改性淀粉絮凝剂具有无毒、原料来源广、价格低、易于生物降解等优点,近年来得到重视和发展应用.文章通过絮凝实验对改性淀粉絮凝剂在不同pH值条件下处理模拟废水的效果进行了初步探讨.实验结果表明,改性淀粉在废水处理中COD去除率效果显著,改性淀粉的混凝效果受不同的pH值的影响不大,优于无机絮凝剂.     

具有变号核的非线性Hammerstein积分方程的固有值与固有元

研究了一类具有变号核的非线性Hammerstein积分方程的固有值与固有元,减弱了文献〔1〕中定理4相应的条件,而得到了同样的结果.因而改进了〔1〕中相应结果.     

餐饮业废水的处理方法

本文综述了餐饮废水处理方法的现状,主要介绍了物理化学法、电化学法及生物法的应用,并对餐饮废水的处理方法作出了分析及建议。     

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.     

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。