蘑菇湖水库水资源的污染现状和保护对策

在蘑菇湖水库近10年水质资料的基础上,分析了水库的污染现状,并采用内梅罗污染指数法进行评价,评价结果表明,蘑菇湖水库属于五级重污染;对水库进行富营养评价、分析结果表明,该水库是富营养水库,针对目前该水库水质情况,提出了该水库水资源的保护对策.     

江西省玉山县"七一"水库水质状况评价

采用熵权综合指数法评价江西玉山县"七一"水库水质状况,首先建立评价矩阵,对矩阵标准化处理后采用熵权法确定各评价时各水质指标所占权重系数,继而在Arcgis 10. 0中对各水质指标进行赋分,分级显示出水库在2013年各季度水质评价图,并对Arcgis中评价结果采用"交叉验证"法对其精度进行验证,结果表明:在评价"七一"水库水质时先采用熵权综合指数法确定各水质指标权重,随后在Arcgis中赋分显示的水质评价图整体效果较好,评价精度也较高;"七一"水库上游至下游水质逐渐变差,至下游断面时水质已不能满足Ⅱ类水质标准。评价结果可为水库水质管理提供轮参考。     

BP网络应用于黄河水质的预测研究

利用黄河兰州段水质指标浓度时间序列作为学习样本，选取了DO、COD、氨氮、重金属离子等l0项指标作为输出参数，运用人工神经网络BP模型中的Levenberg—Marguardt优化算法对学习样本优化建模，将优化好的网络的预测结果与实测结果进行了比较，表明BP网络可以很好地用于黄河水质指标值及水质类别的预测。     

改进的BP神经网络在浑河水质评价中的应用

采用改进的动量-自适应学习率调整的 BP 神经网络,以国家水环境质量标准作为训练样本,以黄河流域的大汶河水系的水质监测数据作为检验数据建立了一个多前馈网络数学模型,应用此模型对浑河沈阳区段的水质进行评价,由于网络的改进有效地提高了训练的速度、节省训练时间,并且提高了评价的准确性。     

基于模糊BP神经网络的水质评价

在BP网络模型基础上构建了隶属度BP网络模型,针对模型特点,建立了水质评价标准指标矩阵,并采用扩展方法构建了网络训练样本,将所建立的模型应用于佛山某污水处理厂的出水口水质评价,应用模糊隶属度方法实现水质级别评价,可以简明地表示水质接近于某类标准水质的程度。研究表明,本算法使评价的结果更具体准确、更符合评价水体水质情况,...     

Hadoop下并行BP神经网络骆马湖水质分类

研究借助云的计算向数据迁移机制及MapReduce并行处理海量数据的优势,解决BP神经网络在处理大规模样本数据时计算量大、网络训练时间长的瓶颈问题.构建了影响骆马湖水质的多污染因素评价网络模型,在Hadoop下应用并行BP网络算法,实现了对骆马湖水质分类挖掘,挖掘分析结果对骆马湖水质优化及生态修复具有决策支持性意义.     

对宝鸡市人民公园人工湖水质的评价与分析

以宝鸡市人民公园湖为例,对其水质指标总氮、氨氮、磷、CODcr进行监测,采用模糊综合评价法和浓度指数法对其现状水质进行评价与分析.结果表明该公园湖水体水质为Ⅴ类,水质污染严重.并提出了水质污染治理的建议和措施.     

炼油企业可持续发展评价模型

从经济、社会、科技、环境、资源5个方面对炼油企业可持续发展水平进行了综合评价，建立了评价指标体系。针对指标体系中各种指标由于度量单位不同而无法进行直接比较的问题，采用效用函数法对各项指标进行了无量纲处理。用层次分析法确定了指标的权重，通过求解最大特征根及其对应的特征向量，确定了表达每一层次元素相对重要性的权值，进而导出对整个问题的分析。利用BP神经网络分析法建立了网络评价模型，并采用实际数据样本对网络进行了训练和检验，得到了与实际评价值基本吻合的结果。     

基于人工神经网络的本科教学工作水平评估系统设计

本文首先采用了模糊聚类方法对影响本科教学工作水平的18个主要指标进行了聚类,找出了最具代表性的6个指标。其次,建立了本科教学工作水平评估的BP网络模型,将最具代表性的6个指标的评价值和综合的评估值分别作为网络的输入和输出。最后,在采集的10组样本数据中选取前9组和最后一组分别作为训练样本和测试样本,并采用梯度法对网络模型进行了训练。结果验证了系统的有效性。     

黄河水质综合评价的人工神经网络模型

为探讨水质综合评价的客观方法 ,以黄河兰州段新城桥段面水质资料为例 ,建立了地表水水质综合评价的BP网络模型 BP网络模型以单输出代替多输出可保证评价结果的惟一性 .将该模型用于实例分析表明 ,BP网络用于水质综合评价具有客观性和实用性 .     

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