生物接触氧化法处理农村河道受污染水体中试研究

为了提高生物接触氧化法修复农村受污染河道水体的处理效果,构建了处理规模为150 m~3/d的河道模拟装置,系统开展了生物接触氧化法处理农村河道受污染水体运行控制参数优化研究。讨论了弹性填料、组合填料、悬浮球填料在较佳工况下对CODCr、NH_4~+-N、TN、TP的去除效果。结果表明:气水比6∶1~8∶1、CODCr容积负荷0.1~0.5 kg/(m~3·d)、水力负荷2.4~7.2 m~3/(m~3·d)时,系统对污染物有较好的去除效果。中试系统较优工况运行时,相较于空白对照,装填填料对各污染物的去除效率提高20%~30%。组合填料对CODCr、NH_4+~-N、TN、TP的去除率分别稳定在74.87%、78.37%、34.39%、44.69%以上,优于弹性填料和悬浮球填料。研究结果可为提高生物接触氧化法对农村河道受污染水体处理效果提供技术支持,对生物接触氧化法修复受损河道水体工程实践具备一定的参考意义。     

悬浮填料生物反应器石化废水生物硝化研究

采用自行研制的悬浮填料生物反应器中试装置对石油化工废水进行处理.通过6、8、10和12h四个不同水力停留时间的硝化过程取得了不同运行条件下的氨氮去除效果.结果表明,悬浮填料生物反应器完全可以达到生物硝化的目的.当进水中BOD     

生活污水膜处理技术试验研究

对悬浮填料生物膜工艺处理城市生活污水的性能进行了研究．结果表明，在水力停留时间大于8小时，反应器填料投加率为50％条件下，对COD、NH3-N、SS等均有良好的去除效果。悬浮填料生物膜工艺具有挂膜时间短、氨氮去除高、传质效果好、占地面积小及运行维护方便等优点。     

硝化-反硝化曝气生物滤池改进工艺处理水产养殖废水

采用出水回流的上流式曝气生物滤池处理模拟水产养殖废水,逐一优化厌氧/好氧(A/O)一体化曝气生物滤池中水力负荷、气水体积比以及硝化液回流比等3个因素,通过分析出水水质确定最佳运行参数.结果表明:1)设定厌氧/好氧区域体积比为1∶1,当工艺中水力负荷为39.86m3·(m~2·d)~(-1),硝化液回流比为200%,气水体积比为2∶1,水力停留时间为1.81h时,污染物去除效果最佳,化学需氧量(chemical oxygen demand,COD)、氨氮、总氮和总磷的平均去除率分别达71.09%,96.29%,78.26%,17.22%;2)各优化条件下,当A/O体积比为1∶1时,该改进工艺下总氮去除效果可达GB 3838—2002《地表水环境质量标准》中的Ⅲ类标准.     

PVF悬浮填料的制备及其污水处理效果的研究

制备了一种新型的高分子多孔载体——活性泡沫填料，它是聚乙烯醇和甲醛的缩聚物(PVF)。其比表面积大、密度接近于水，具有良好的亲生物特性，可作为悬浮填料在移动床工艺中为微生物提供附着生长的载体。研究表明，在复合式生物反应器中加入不同活性炭质量分数的两种活性PVF泡沫填料处理模拟生活污水，其COD的去除率在95%以上，氨氮的去除率为80%左右。在相同的工艺条件下活性炭质量分数为8％的PVF填料COD的去除效果和反硝化效果更为理想。当两填料体系中COD与NH_4⁺-N的质量浓度比为20时，两系统的同时硝化反硝化（SND）效果均为最理想。     

填料类型和曝气条件对生物栅微生物群落的影响

以水生植物和填料为要素构建生物栅装置,用以强化处理富营养化水体.实验采用6m3.d-1的中试规模,7个廊道并联运行,连续进出水.研究不同的填料类型和不同曝气条件下的污染去除效果以及填料生物膜微生物群落结构的变化.结果表明,填料在污染去除中起重要作用,投加填料的反应池CODCr、总氮和氨氮的去除率较无填料对照池分别提高了42.1%~52.2%,24.4%~47.8%和58.7%~71.4%.悬浮填料生物膜微生物相对处于好氧生境,有利于COD和NH4+的好氧氧化去除,而组合填料和新型填料存在兼性厌氧的生境,有利于总氮的去除.采用间歇曝气的方式可以一定程度地提高系统污染去除效率.ERIC-PCR指纹图谱分析表明,填料挂膜阶段,3种填料生物膜带型相似,随着系统挂膜成熟及稳定运行,填料生物膜带型分化成两大类型.悬浮填料为一大类型,组合填料和新型填料为另一类型.3种填料生物膜微生物种群丰富度明显提高.间歇曝气的3号和5号条带微生物的种群丰富度高于未曝气的2号和4号,有利于污染物的去除.总之,随着系统的稳定运行,填料生物膜微生物多样性指数显示出逐渐增大的趋势,表明系统中微生物种群趋于多样化,系统处于良好的稳定状态.     

Application of High-Rate Up-Flow Biological Aerated Filter to Pretreatment for Large-Scale Waterworks

为克服氨氮和有机物对饮用水源的微污染,广州市某水厂首次采用了高速给水曝气生物滤池(HUBAF)生物预处理新工艺,处理规模为73.5万m3/d.工程投产稳定运行后,初期3个月原水氨氮和CODMn分别为0.44～2.22 mg/L和1.84～6.06 mg/L,预处理出水分别小于0.5 mg/L和2.0mg/L;原水的铁和锰最高达1.16 mg/L和0.22 mg/L,出厂水最高达0.05 mg/L和0.03 mg/L.HUBAF采用大颗粒轻质陶粒并结合流化床技术,对浑浊度的去除平均仅为2.5 NTU,生物滤池过滤水头损失稳定在1.0m以下.其冲洗方式为气水联合上、下冲洗,冲洗前后各滤池的过滤水头损失差不超过0.1m,为共用1套集中鼓风曝气系统创造了条件.与弹性填料接触氧化池和悬浮球流化池等已投入应用的生物预处理技术相比,HUBAF抗冲击负荷能力强,氨氮硝化率高,除铁除锰能力强.HUBAF-常规工艺生物强化集成技术对有机物的去除率与“臭氧-生物活性炭”给水深度净水工艺处于同一水平.     

高速给水曝气生物滤池应用于大型自来水厂的预处理

为克服氨氮和有机物对饮用水源的微污染,广州市某水厂首次采用了高速给水曝气生物滤池(HUBAF)生物预处理新工艺,处理规模为73.5万m3/d.工程投产稳定运行后,初期3个月原水氨氮和CODMn分别为0.44～2.22 mg/L和1.84～6.06 mg/L,预处理出水分别小于0.5mg/L和2.0mg/L;原水的铁和锰最高达1.16mg/L和0.22mg/L,出厂水最高达0.05mg/L和0.03mg/L.HUBAF采用大颗粒轻质陶粒并结合流化床技术,对浑浊度的去除平均仅为2.5NTU,生物滤池过滤水头损失稳定在1.0 m以下.其冲洗方式为气水联合上、下冲洗,冲洗前后各滤池的过滤水头损失差不超过0.1m,为共用1套集中鼓风曝气系统创造了条件.与弹性填料接触氧化池和悬浮球流化池等已投入应用的生物预处理技术相比,HUBAF抗冲击负荷能力强,氨氮硝化率高,除铁除锰能力强.HUBAF-常规工艺生物强化集成技术对有机物的去除率与"臭氧-生物活性炭"给水深度净水工艺处于同一水平.     

化学生物絮凝-悬浮填料床组合工艺中试装置设计

化学生物絮凝工艺是在同一个反应器内充分发挥化学混凝和生物絮凝作用的污水处理新工艺,悬浮填料床工艺对氨氮的去除具有特殊功能,本文介绍了化学生物絮凝-悬浮填料床组合工艺中试研究装置的设计思路及建设情况,并建立了平行的化学混凝工艺,可以进行化学生物絮凝工艺和化学混凝工艺的比较研究,对该中试装置的工艺流程、各主要构筑物设计参数和设计上的一些特点进行了详细介绍.     

牡蛎壳填料曝气生物滤池去除水源水中的氨氮

采用以牡蛎壳为填料的内循环曝气生物滤池,对模拟水源水中氨氮进行处理,考察了水力停留时间、曝气量、pH值等因素对氨氮去除效果的影响.结果表明,该系统在水力停留时间为4 h,曝气量为2.0 L/min,pH=7.5~8.0的最佳条件下,对氨氮的去除率达到90%以上,出水氨氮浓度达到《地表水环境质量标准》(GB 3838—2002)中Ⅱ类水体的水质标准.可见,牡蛎壳是一种较好的曝气生物滤池填料,内循环可以显著提高曝气生物滤池脱氮效果.     

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。