21世纪城市绿地系统规划的认识与思考

针对目前城市绿地系统规划中存在的主要问题,提出城市绿地系统规划必须建立与城市总体规划相协调的关系和对应的编制体系,树立城市大园林的思想,科学制定城市绿地规划指标,重视“氧源绿地”和“城市通风走廊”的建设并指出城市绿地系统的发展趋势。     

创新城市绿地系统规划思路的探讨

目前城市绿地系统规划存在特色不够突出,实施性、可操作性较差的普遍问题.文章以铜陵市绿地系统规划为例,从宏观和微观两个层次探讨如何挖掘和提升城市的特色,如何提出科学合理的城市绿地系统规划方案、如何制定易于操作的绿地建设指标,并对滨水绿地规划建设方法进行了探讨.     

岳阳市生态园林城市建设

以生态学理论为基本原则,根据国家园林城市建设标准,提出了岳阳市生态园林城市建设和城市绿地规划的建议。岳阳市生态园林城市绿化建设的目标是：到2005年规划建设绿化覆盖率达到36％,绿地率达到32％。人均公共绿地面积9m^2;到2015年规划建设绿化覆盖率达到40％,绿地率达到35％,人均公共绿地面积13m^2。规划中注重城市生态体系的建立。注重保持生态平衡、保护生物多样性,通过城市绿化和生态园林的建设,达到人与社会、环境的和谐。     

城市绿地系统规划—以辽宁省朝阳市为例

为保证有序的城市建设和环境生态的可持续发展,编制城市绿地系统是非常必要的.城市绿地系统内容包括编制、深化、落实绿地的指标、要求、内容.充分利用人文资源和自然生态环境资源,形成城乡统筹、协调发展的绿色体系.城市绿地系统规划为政府启动建设、公共投入、开发控制提供工作框架,指导近期发展建设的可操作性,控制落实长远规划.     

城市绿地系统规划的特色塑造探讨

每个城市有它自身的地域特征和地方历史文化特色,一座城市的绿地系统在一定意义上反映了城市的特色.精神和物质是城市绿地系统规划的两个特色要素.在城市绿地系统规划中,必须从城市自然景观、本土人文环境和人工环境三方面综合着手来塑造城市特色     

南阳油田资源型城市绿地系统规划初探

城市绿地系统对美化城市、改善城市生态环境质量起着极大的作用,是城市生态环境的重要组成部分。本论文以南阳油田为例,探析油田资源型城市绿地系统特点、建设现状及存在的问题,结合油田实际,提出油田资源型城市绿地系统规划策略,并为同类型城市绿地系统规划提供参考。     

我国城市绿地系统的规划与建设

城市绿地系统作为城市自然系统的主体,发挥着重要的生态功能.我国城市绿地建设普遍滞后,现在的城市绿地系统规划还存在不少问题,本文在分析绿地功能的基础上指出了在我国城市绿地系统规划与建设中所存在的几个主要问题,粗略地点明了解决这些问题的几点对策,尝试构建了使我国城市绿地系统规划顺利进行的内外条件.     

郑州市生态绿地系统发展的思路及对策

本文从宏观区域角度出发,将绿化纳入城市自然经济社会复合系统,以生态学原理和花园城市理论为基本指导思想,讨论了城市绿地系统规划的基本原则,并以郑州市为例,从确定绿地规划指标,合理布局绿地系统及重点建设工程三方面提出了绿化发展的思路与对策．     

固原市城市绿地系统规划

《固原市城市绿地系统规划》是《固原市城市总体规划》的重要专项规划，是城市绿地建设、管理的基本依据，是改善城市生态和人居环境的指导性文件。     

城市绿地科学规划探讨

介绍了城市景观和城市绿地系统对城市景观的贡献，分析了城市绿地系统规划层次，指出各规划层次的规划原则、目标、具体内容及实施规划的措施，提出了科学编制城市绿地系统规划应考虑的6个基本问题和打造生态园林城市的10项建议。     

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。