区域空间网络化概念模型与过程研究——以泛长三角为例

区域空间网络化是空间组织演化的必然趋势.泛长三角这一巨型的区域空间,将是我国未来优化经济发展空间格局的重点区域,也是研究空间网络化的典型案例区.基于已有的研究基础,提出区域空间网络化的概念模型假设,以泛长三角41个地级市为基本研究单元,通过修正的空间相互作用模型、潜能模型计算1996年、2002年、2008年、2014年城市潜能及城市间经济联系强度,同时借助社会网络分析方法(SNA)与反距离权重空间插值法(IDW),从节点、联系轴线、网络3个维度实证分析泛长三角区域空间网络化过程及其特征.研究表明:1)在1996年至2014年间,区域内各地城市潜能增幅显著,城市间联系加强且空间关联渐趋复杂化,泛长三角地区网络密度不断提高;2)城市的发展从低级到高级,空间结构由单核到多中心,城市等级体系走向偏平化特征,空间关联由孤立走向网络化;3)泛长三角网络化过程经历了4个明显阶段:从单中心集聚模式、点轴扩散模式、核心-边缘模式到多中心网络化模式.最后,对泛长三角区域空间网络化演化机理进行论述.对泛长三角空间网络化过程的研究,刻画了典型区域空间一体化及其形态演化过程,也为正在实施的区域经济一体化、长三角城市群的建设提供理论上的支撑.     

区域一体化对旅游经济增长影响的机制研究——来自长三角城市群的准自然实验

区域一体化日益成为旅游经济增长的重要诉求，对驱动旅游高质量发展具有深刻意义.本文基于2002—2019年中国217个地级及以上城市数据，通过构建双重差分模型(DID)实证检验了长三角区域一体化政策对旅游经济增长的影响，并对其作用机制展开探析.研究发现：(1)长三角区域一体化政策能显著促进旅游经济增长，且经过PSM-DID检验、安慰剂检验等之后，结论依然成立；(2)长三角区域一体化政策的旅游经济效应具有即时性、异质性特征，在政策实施当期便能发挥效益，且对核心城市旅游经济的影响程度明显高于非核心城市；(3)长三角区域一体化政策能通过技术创新、产业集聚、产业结构升级等传导路径促进旅游经济发展，且通过旅游产业集聚影响旅游经济增长的正向效应最大，科技创新次之，产业结构升级最小.     

长三角地区旅游产业集聚水平测度及差异分析

旅游产业集聚是旅游经济空间发展的必然趋势．笔者选择长三角区域16个城市为案例地,采用区位商、区位商变化率的方法,对区域旅游产业进行集聚水平的测定．认为长三角区域旅游产业集聚可以划分为成熟型、增长型、成长型等3种类型．文章在分析3种集聚类型特点的基础上,提出提升长三角地区旅游产业集聚水平的策略,以期促进该区域旅游产业的可持续发展．     

基于EG指数的长三角安徽省经济带旅游产业集聚结构性探究

长三角经济带是中国经济发展水平较高的地区,其旅游业发展水平也较高。已有研究表明,旅游产业集聚能够对区域旅游经济产生重要影响。对安徽省的长江经济带核心区展开研究分析,首先通过EG指数法和区位熵对合肥等八市旅游产业集聚度进行宏观定量测度,分析其产业集聚变化趋势和成因;再采用PCA法从微观角度探索这八个城市的产业集聚影响因素,得到集聚度影响因子综合模型。研究表明:合肥市、芜湖市、马鞍山市、铜陵市四市呈现"高—高"集聚结构;滁州市呈现"高—低"的集聚结构;而其他城市旅游产业集聚结构表现不显著。从集聚度模型来看,产业经济效应和关联产业联动效应是旅游产业发展支撑的主要支柱,其次是生态效应。从而为安徽省长三角旅游产业发展提供理论依据和政策建议。     

长三角和中原城市群城市扩张时空特征及驱动力比较研究

以长三角城市群和中原城市群为研究对象,以1990、1995、2000、2005和2010年五期土地利用现状遥感监测数据和2010-2014年统计数据为基础,采用网格化统计方法、局部空间统计(LISA)方法、城市扩张动态度指标和地理探测器方法,比较研究了两个城市群地区城市扩张的时空特征和驱动力机制.研究表明:(1)长三角地区城市快速扩张期主要在2000-2005年和2005-2010年后期两个阶段,在2000-2005年长三角地区城市扩张净增面积(2 759km2)、净扩张率(36.63%)、年均扩张率(7.33%)均达到最高.而中原城市群地区主要在前期三个阶段(1990-1995年、1995-2000年、2000-2005年)出现快速扩张,在前两个阶段其城市扩张净率和动态度均高于长三角地区.(2)长三角地区城市扩张过程呈现出"点-轴-波式循环"模式,中原城市群则以传统自然的"点-轴-网"模式扩张.长三角地区在四个城市扩张阶段中,都出现了显著的城市扩张空间热点区域,并且随着扩张阶段的不同,扩张热点区域动态转移,而中原城市群城市扩张却未出现空间集聚现象,并没有表现出显著的空间异质特征.(3)长三角城市群和中原城市群城市扩张均受到经济因素、人口规模、居民收入、产业结构、交通以及地理要素等因素影响,两者不同的是:经济因素是长三角城市群城市扩张的主要驱动力,而中原城市群城市扩张的主导因素却是人口因素.     

生产性服务业集聚发展对区域产业结构优化升级的实证研究

基于长三角16个中心城市的面板数据,运用区位商指数法测算和分析长三角地区生产性服务业集聚现状,并采用面板数据模型中的固定效应模型,以产业结构为因变量,以区位商计算出来的生产性服务业集聚度为核心解释变量,引入科技进步、教育水平和研发投入三个控制变量,实证研究了生产性服务业集聚对区域产业结构的影响。结果表明,生产性服务业集聚对长三角区域产业结构优化升级具有显著的正向推动作用,但推动程度不是很大,有待进一步加强。     

长三角主题公园时空演化特征及影响因素分析

近年来主题公园在中国长三角地区发展迅速,作为经济及社会文化地理现象,其时空演化特征及其影响因素的研究,对指导主题公园产业合理布局、发展及区域文化建设具有重要意义。采用最邻近指数、核密度分析法探究1985-2021年36年间长三角地区主题公园的时空演化特征,并应用地理探测器分析了影响其空间分布的主要因素。结果表明:(1)1985—2021年,长三角主题公园数量逐年上升且阶段性分布明显,其发展过程经历了“初步探索期”“缓慢增长期”“快速增长期”三个发展阶段。(2)主题公园空间分布经历了从离散到不断集聚的演化过程。主题公园空间分布总体呈现出中东部密集,四周多组团的分布格局,并呈现以所在的核心区不断向周围扩散的趋势。等级规模越大的主题公园在空间分布上越为均衡。不同主题内容的主题公园,以游乐休闲类分布最广,其余主题公园分布较为集中。(3)经济发展水平、交通条件是影响长三角主题公园空间分布的主要因素。研究最后根据所得结论提出相关建议,对长三角主题公园的空间优化提供一定的参考和借鉴。     

中国制造业产业空间演化格局及其动力机制

用重力测度方法,对中国制造业总体及28个二位数制造业2000—2014年产业规模(总产值)和产业活动(流动资产、固定资产和劳动力)重心轨迹变迁进行分析,显示制造业总体呈向西转移,28个二位数产业重心也出现不同程度转移趋势。从异质性生产视角,考察中国制造业产业空间演化格局的动力机制。研究表明,从全国整体上看,要素生产效率(劳动力和流动资产)、集聚外部性、市场规模和人力资本对中国制造业空间布局有显著影响,交通基础设施、劳动力成本和对外开放度对制造业空间布局影响不显著。此外,不同区域制造业空间格局的动力影响因素以及同一区域在不同时序内的影响因素也存在差异。     

生产性服务业集聚发展对区域产业结构优化升级的实证研究——基于长三角16个中心城市的面板数据

基于长三角16个中心城市的面板数据,运用区位商指数法测算和分析长三角地区生产性服务业集聚现状,并采用面板数据模型中的固定效应模型,以产业结构为因变量,以区位商计算出来的生产性服务业集聚度为核心解释变量,引入科技进步、教育水平和研发投入三个控制变量,实证研究了生产性服务业集聚对区域产业结构的影响。结果表明,生产性服务业集聚对长三角区域产业结构优化升级具有显著的正向推动作用,但推动程度不是很大,有待进一步加强。     

《产业集聚与集聚经济圈的演进》书评

研究集聚经济圈产业集聚规律,通过发展集聚经济圈的产业集聚,促进集聚经济圈的形成与合理演化,对于拓展区域经济学和发展经济学相关理论,提升发展中国家经济竞争力而言,意义重大.由浙江工业大学经贸管理学院胡晨光副教授主持完成的国家社科基金后期资助项目"产业集聚与集聚经济圈的演进",主要以中国长三角的经济发展为例,从集聚经济圈的视角,探讨了集聚经济圈形成过程中产业集聚的动力、效应与演化等产业集聚规     

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…     

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.     

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。     

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     

《Chinese Science Bulletin》SUBJECT INDEX TO VOLUME 59(2014)

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An on-line scaling method for improving scalability of a database cluster

The explosive growth of the Internet and database applications has driven database to be more scalable and available, and able to support on-line scaling without interrupting service. To support more client's queries without downtime and degrading the response time, more nodes have to be scaled up while the database is running. This paper presents the overview of scalable and available database that satisfies the above characteristics. And we propose a novel on-line scaling method. Our method improves the existing on-line scaling method for fast response time and higher throughputs. Our proposed method reduces unnecessary network use, i.e. , we decrease the number of data copy by reusing the backup data. Also, our on-line scaling operation can be processed parallel by selecting adequate nodes as new node. Our performance study shows that our method results in significant reduction in data copy time.     

An improved R-tree based on childnode''s probability

R-Tree is a good structure for spatial searching. But in this indexing structure,either the sequence of nodes in the same level or sequence of traveling these nodes when queries are made is random. Since the possibility that the object appears in different MBR which have the same parents node is different, if we make the subnode who has the most possibility be traveled first, the time cost will be decreased in most of the cases. In some case, the possibility of a point belong to a rectangle will shows direct proportion with the size of the rectangle. But this conclusion is based on an assumption that the objects are symmetrically distributing in the area and this assumption is not always coming into existence. Now we found a more direct parameter to scale the possibility and made a little change on the structure of R-tree, to increase the possibility of founding the satisfying answer in the front sub trees. We names this structure probability based arranged R-tree (PBAR-tree).     

Integrating GIS Web services based on mediating architecture

The geographic information service is enabled by the advancements in general Web service technology and the focused efforts of the OGC in defining XML-based Web GIS service. Based on these models, this paper addresses the issue of services chaining,the process of combining or pipelining results from several interoperable GIS Web Services to create a customized solution. This paper presents a mediated chaining architecture in which a specific service takes responsibility for performing the process that describes a service chain. We designed the Spatial Information Process Language (SIPL) for dynamic modeling and describing the service chain, also a prototype of the Spatial Information Process Execution Engine (SIPEE) is implemented for executing processes written in SIPL. Discussion of measures to improve the functionality and performance of such system will be included.