钽铌矿冶炼铁泥制备聚硅酸硫酸铁及其应用

以Fenton法处理钽铌冶炼废水产生的铁泥为原料,制备了聚硅酸硫酸铁(PFSS)絮凝剂.研究了PFSS的制备工艺条件、PFSS投加量、废水的 pH值和搅拌时间对PFSS絮凝性能的影响.结果表明,当制备工艺条件中的SiO2质量分数w(SiO2)为1.00%,A,B混合液pH值为3.00,n(Fe)∶n(Si)为1∶1,活化温度为40 ℃,活化时间为2 h时,得到的PFSS具有最好的絮凝性能.用PFSS絮凝剂处理钨铋选矿废水,PFSS投加量为废水体积分数0.10%,废水pH值为7.00,搅拌2 min后,废水浊度去除率达99.9%,COD去除率达77.8%;废水中Pb和As去除率分别达99.0%和97.4%,Be去除率几乎达100%.处理后废水浊度为0.32 NTU,COD含量降至72.2 mg/L,废水中Pb和As质量浓度分别降至0.08和0.03 mg/L,Be未检出.处理后废水达到GB 8979-1996一级排放标准.     

新型复合聚硅硫酸铁铝（PFASSi）的形态分布研究

PFASSi的形态分布研究表明，它的最优技术指标为B=1．5～2．0，Fe Al／Si或Fe／Al摩尔比均为10：1，pH为2．0～4．0，熟化24h；硅的加入会产生很强的协同效应，使无机高分子絮凝剂PFASSi较单纯聚硅酸和单纯的聚铁的絮凝能力增强很多，有效成分高，絮凝效果更好。     

粉煤灰基絮凝剂PAFSi的制备

以粉煤灰为原料制备了无机高分子絮凝剂聚硅酸铝铁（PAFSi），考察了Al／Fe，Si／（Al＋Fe），聚合温度、时间及pH值对絮凝剂性能的影响，确定了制备的最佳工艺条件：Si／（Al＋Fe）为2：1；Al：Fe为3：1；聚合温度为50℃，聚合时间为2h．用于处理模拟低浊度废水取得了较好的效果．     

用聚合硅酸铁处理砷化镓晶片生产废水的研究

用自制的无机高分子聚合硅酸铁(PFSS),对砷化镓生产中的含砷废水进行了混凝处理。实验考察了n(Fe)/n(Si)、熟化时间、使用量、出水pH值等对PFSS混凝效果的影响,并与通常所用的几种混凝剂进行了比较。结果表明:在n(Fe)/n(Si)为1∶(0.5～1)、熟化时间为5～7d、使用量为8～12mg/L、出水pH值为6～8时,效果较好,且除砷效果优于常规混凝剂。     

高效絮凝剂的制备及其对印染废水的处理

利用硅酸钠、硫酸铝、硫酸锌和硼砂为原料制得高效絮凝剂PSZBAS.分析不同影响因素对PSZBAS絮凝性能的影响.确定了最佳制备工艺条件:硅酸聚合pH=3,硅酸聚合时间为45min,n(B)∶n(Si)=0.125,n(Al)∶n(Si)=2,n(Zn)∶n(Si)=1,模拟废水处理的絮凝剂投加量=10mL/L.实验表明,用PSZBAS处理实际印染废水,电中和能力和吸附架桥能力强,絮凝效果较好,最佳投加量为25mL/L.     

水热改性制备固体酸S2O8^2-／Fe2O3-SiO2及其催化性能的初步探讨

采用共沉淀法制备Fe2O3—SiO2混合氧化物前驱体，并对其进行水热改性处理，经浸渍(NH4)2S2O8溶液后再焙烧得S2O8^2-／Fe2O3—SiO2固体酸催化剂。研究了制备条件对催化活性的影响，用乙酸／丁醇酯化反应评估该固体酸的催化性能。实验结果显示，最佳工艺条件为，n(Fe)：n(Si)=1：4，150℃水压热处理1h，在0．5mol．L^-1的(NH4)2S2O8溶液中浸渍6h，500℃焙烧3h，在此条件下乙酸的转化率可达94．11％。     

高稳定性聚硅酸氯化铁铝的制备及絮凝性能研究

以水玻璃,氯化铁和氯化铝为原料研究制备了高稳定性聚硅酸氯化铁铝(PAFSC)。实验结果表明,其最佳制备条件为:水玻璃浓度为0.97 mol/L,三价铁离子与三价铝离子的摩尔比为1∶2,三价铁离子和三价铝离子与二氧化硅的摩尔比为(1 2)∶2,活化pH值为2.0,室温活化时间为4h。用此法制备的聚硅酸氯化铁铝可稳定存放12个月以上,并对油田废水、洗煤废水、烟草工业及生废水都具有良好的絮凝净化效果。     

聚硅酸铝的絮凝性及稳定性研究

在制备聚硅酸氯化铝（PSAC）和聚硅酸硫酸铝（PSAS）的基础上，考察了水玻璃浓度，Al/Si摩尔比对聚硅酸氯化铝稳定性的影响，研究了水玻璃浓度；Al/Si摩尔比，铝盐种类，放置时间和搅拌强度对聚硅酸铝絮凝沉降效果的影响规律，结果表明，聚硅酸铝的稳定性随水玻璃浓度增加而降低；PSAS与PSAC絮凝性能的差异和Al/Si摩尔比密切相关，PSAC在Al/Si摩尔比为0．75－1时絮凝效果较好，而PSAS在Al/Si摩尔比较低时絮凝效果好，搅拌强度和放置时间也明显影响药剂的絮凝效果。     

复合絮凝剂聚硅酸铁锌(PSZF)的絮凝性能

利用复合共聚法合成了一种新型无机高分子复合絮凝剂——聚硅酸铁锌（PSZF）．考察了PSZF投加量、污水pH值及熟化时间对PSZF絮凝性能的影响,并对其沉降性能及Zeta电位进行了研究。当PSZF投加量为2mL／L、污水pH为8时,其除浊率达到94．6％,把PSZF应用于黄浦江水处理,发现其絮凝效果明显优于PSA,Fe2（SO4）3和PSF．PSZF的形貌为长链枝杈状聚集态,具有优良的稳定性和混凝特性．     

无机高分子复合絮凝剂的制备及絮凝性能研究

制备无机高分子絮凝剂＿硅钙复合型聚合氯化铝镁锌(SCPAMZC),考察了不同pH值条件下水玻璃的胶凝时间,SiO2/Al(硅铝比),Mg/Zn,Ca/Zn,Ca Mg Zn/SiO2等因素对其絮凝性能的影响,确定了最佳制备条件为pH值2～4,SiO2/Al为1/0.7左右,Mg/Zn和Ca/Zn分别为1,Ca Mg Zn/SiO2为0.3。经应用实验表明:SCPAMZC用于印染废水和生活污水处理,具有优异的絮凝性能。     

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