琼北乡村聚落边界形状的量化研究

以琼北地区的20个传统乡村聚落为研究样本,运用图底分析的方法,借助景观生态学中的3个斑块形状指数:即图形的周长面积比SI1、图形周长与等长宽比等面积的椭圆周长之比SI2和景观分维数SI3分别对样本进行量化分析,结果表明:采用分维数SI3先对聚落边界图形进行初步筛分排序,然后再结合图形外接矩形(弧形)的长宽比和形状指数SI2进行进一步的分析,可以更全面地了解图形的复杂性和破碎度,并且可应用此方法来研究琼北地区乡村聚落的形态特征.     

乡村聚落时空分布特征及驱动因素分析——以安徽黟县为例

【目的】基于遥感数据和3S技术进行乡村聚落时空分布特征及演变规律研究,为推进美丽乡村建设和实现地区可持续发展提供参考。【方法】以安徽省黟县为对象,基于核密度分析、GIS空间分析、景观格局指数以及空间自相关等分析方法,探究研究区2010年、2012年、2014年、2016年4年乡村聚落的时空分布特征与景观格局变化的驱动因素。【结果】2010年与2012年黟县各村镇之间的乡村聚落核密度估值呈较弱的聚集分布,2014年与2016年黟县各村镇之间的乡村聚落核密度估值呈显著的聚集分布状态; 2010年、2012年、2014年、2016年的Moran's I指数均大于0,黟县乡村聚落存在正的空间相关性,2016年Moran's I指数较2014年的低; 黟县乡村聚落核密度估计值相似的地区在空间上聚集分布的趋势有所减弱,空间分布的差异性在增强; 地势、河流等自然因素以及道路、城镇经济、人口变化等社会因素影响黟县乡村聚落分布格局的演变。【结论】黟县乡村聚落的时空分布格局特征与演变研究能够为美丽乡村建设中的合理规划、聚落优化、土地资源利用以及可持续发展规划建设提供理论依据。     

乡村旅游发展下海口乡村聚落景观的变化——以美社村为例

乡村旅游的发展导致了海口市乡村聚落景观的显著变化.在此背景下,本文结合海口市美社村近10年聚落景观的变化,揭示了海口市乡村聚落景观在旅游发展下的变化动因及变化机制,认为其主要在于满足乡村旅游的可达性、娱乐性和服务性;同时,总结了聚落景观变化的特征,即功能旅游化、尺度扩大化、空间开阔化,其具体表现就在道路、建筑、庭院、绿化等景观方面;此外,分析了景观变化对乡村聚落发展的利弊,提出只有在正确规划引导下发展乡村旅游,才能使乡村聚落景观越变越好.     

高寒民族地区乡村聚落边界形态量化研究——以甘南州夏河县为例

以夏河县13个村落为研究对象,运用图底分析方法,选取合理的地理研究模型,构建乡村聚落边界的量化指标体系,将乡村聚落边界的相关数据进行量化,探讨高寒民族地区乡村聚落的形态特征.结果表明,乡村聚落形状受自然环境(地貌、气候、水文)、人文因素(佛教文化、宗族观念)及人工构筑物(历史遗迹、公共服务设施)等的影响,表现出团状与带状2种类型;乡村聚落的扩张与衰退及聚落中村民生产生活方式的不同,导致聚落的外边界与内边界互相转化,乡村聚落边界形态呈现简单平滑、复杂凹凸2种形态;通过对聚落边界形态的形状指数和分维数进行分析,乡村聚落边界形态类型呈现出团状倾向的指状、无明确倾向性的指状、团状、带状倾向的团状及带状5种形态.     

五台山乡村聚落与风景名胜区的依存关联度评价

世界遗产地五台山历史悠久,保存有类型丰富的乡村聚落,是人类与自然环境长期互动的结果。在实地调查及文献梳理的基础上,提出"自然环境、人文环境、开发建设"的关联体系,并运用AHP层次分析法定量确定各个关联因素指标的权重大小,构建聚落与五台山景区之间的依存关联评价模型。最后在乡村聚落关联特征分区的基础上,以射虎川村为例对五台山地区乡村聚落与风景名胜区依存关联做进一步评价分析,以期对五台山风景名胜区范围内的乡村振兴提供可借鉴的依据。     

乡村聚落用地变化类型及其优化调控——以贵阳市东风镇为例

乡村聚落是农村居民的生活空间,也是乡村振兴和优化调控的基本单元.基于斑块形态和面积等角度划分乡村聚落类型,以总变化率和年均净变化率两个指标将东风镇村级研究区划分为增长型活跃区、增减平衡型活跃区、减少型活跃区和变化迟缓型区.结果表明:东风镇乡村聚落的斑块数量呈现逐年增多的趋势,但增幅在下降,乡村聚落景观出现了破碎化现象,...     

湘桂黔地区侗族乡村聚落边界形态特征分析

选取湘桂黔地区25个侗族乡村聚落作为研究样本,在图底分析法的基础上,基于长宽比、形状指数、分维数量化指标探讨侗族乡村聚落边界的形态特征、破碎程度。结果发现：样本聚落形态呈现团状、带状、带状倾向的团状3种类型,其中团状聚落有10个,带状聚落有10个,带状倾向的团状聚落有5个,聚落形态的形成主要受自然环境、人为因素影响;聚落边界图形呈现出简单平滑和破碎复杂2种状态,其形成受自然环境、宗族理念以及聚落形态特征的影响。研究结果可为侗族乡村聚落保护与发展提供参考。     

在驿道文化影响下的琼海留客村的聚落形态

从留客村的选址与聚落空间形态两方面研究了驿道文化对留客村的影响,并运用量化方法计算了留客村聚落边界的形状指数和聚落公共空间的分维数,然后从聚落边界、街巷空间、公共建筑、重要节点四个方面研究了驿道文化对留客村形态特征的影响,从而得出了驿道文化对留客村空间形态的影响,其具体表现在以下五个方面:即聚落边界的形态、街巷尺度、重要节点的位置及排列方式、异姓家族的组团聚居.     

黄土高原地区乡村聚落分布特征与演化模式研究——以宁夏西吉县为例

以宁夏西吉县为研究区,通过运用GIS空间分析与实地调研相结合的方法,探讨乡村聚落分布特征与演化模式.研究表明,西吉县乡村聚落呈现出规模小、地形分异大的基本格局,布局上倾向在水源与交通线附近集聚,房屋建筑结构落后,以竹草土坯结构为主.选取不同地貌地区的典型村庄进行分析,将乡村聚落演化模式归纳为扩展式、整合式、散布式3种,并针对典型村庄的演化过程、规律与内在机制进行相应的讨论.     

影响金华市乡村聚落空间集聚规律的因素分析

以金华市ETM（Enhanced Thematic Mapper）影像及国家1：25万基础地理数据库为主要信息源,经图像识别与实地验证获得了金华市乡村聚落的空间信息,并运用GIS空间分析方法对金华市乡村聚落的空间聚集特征作了定量化分析．结果表明：水系、道路、地形、人口增长和城市化等因素都对聚落的空间集聚有重要影响．1）研究区绝大多数乡村聚落在局部空间上聚集,水系和道路控制了聚落的分布,聚落多沿水系、道路分布,距之越远,聚落数目越少;2）绝大多数聚落分布在海拔150m以下地势较为平坦的盆地底部,而在海拔大于150m的南北两侧的高山丘陵地区,乡村聚落分布相对较少,且绝大多数乡村聚落分布在坡度10°以下,乡村聚落随坡度的增加,聚落的分布逐渐减少;3）人文经济因素对乡村聚落的影响也是不可忽视的．     

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.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

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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海南岛地体及其毗邻陆缘晚中生代—新生代古地磁研究和构造演化

本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。     

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.     

Exciton Seebeck in Molecular Systems

Various applications relevant to the exciton dynamics,such as the organic solar cell,the large-area organic light-emitting diodes and the thermoelectricity,are operating under temperature gradient.The potential abnormal behavior of the exicton dynamics driven by the temperature difference may affect the efficiency and performance of the corresponding devices.In the above situations,the exciton dynamics under temperature difference is mixed with     

Achieving Unusual States of Matter Under High Pressure

The elongation method,originally proposed by Imamura was further developed for many years in our group.As a method towards O(N)with high efficiency and high accuracy for any dimensional systems.This treatment designed for one-dimensional(ID)polymers is now available for three-dimensional(3D)systems,but geometry optimization is now possible only for 1D-systems.As an approach toward post-Hartree-Fock,it was also extended to