基于城市产业结构特征的高铁生产性服务业集散效应——以长三角城市群为例     

唐昭沛  吴威  郭嘉颖  刘玮辰  李晓丽 《地理研究》2021,40(8):2188-2203

高铁对生产性服务业的空间集散效应深受城市特征的影响。根据城市产业发展特征将城市分为二产主导型城市和三产主导型城市,借助双重差分模型探讨高铁对不同产业结构的城市生产性服务业及其细分行业的空间效应差异。结果表明,高铁对生产性服务业及细分行业的集散效应具有显著时滞性和异质性,城市产业结构对其效应产生了显著影响。① 基于生产性服务业整体的研究表明,在静态上,高铁促进二产主导型城市产业空间分散、三产主导型城市产业空间集聚;在动态上,高铁对二产主导型城市的生产性服务业空间集散具有先促进集聚后促进分散的特性,对三产主导型城市的产业效应始终表现为促进集聚。② 对于运输服务业、租赁与商服业而言,无论是静态效应还是动态效应,城市产业结构对其影响均较小,在静态上高铁促进二产主导型城市和三产主导型城市的产业在空间分散布局;在动态上高铁效应总体表现为“不显著-促进分散”的二阶段性。③ 对于金融服务业和研发设计业而言,高铁的静态效应在作用方向上具有一致性,均表现为促进产业集聚,其动态效应受到城市产业结构的影响表现出显著阶段性差异。④ 对于信息服务业而言,高铁对其空间集散的静态效应表现为对二产主导型城市的产业影响不显著,促进三产主导型城市的信息服务业在空间集聚,且其动态效应与静态效应相一致。  相似文献   

基于复杂适应系统理论的旅游地空间演化模式——以皖南旅游区为例   总被引：8，自引：1，他引：7  

杨仲元  徐建刚  林蔚 《地理学报》2016,71(6):1059-1074

根据复杂适应系统理论,旅游地由主体系统、旅游吸引物系统、旅游服务设施系统和外部环境系统四个部分组成,通过多个适应性主体相互作用而形成的复杂适应系统。论文选择皖南旅游区为案例地,探讨了其空间演化过程。结果显示：① 1979-1990年是空间聚集体形成阶段,以黄山和九华山为核心的旅游吸引物逐步得到开发利用并形成规模“聚集”,旅游空间结构开始呈现集聚发展特征。② 1991-2000年为空间聚集体增长时期,黄山景区和九华山景区进一步发展,旅游设施进一步完善,同时西递、宏村景区的快速发展推动新的空间聚集体形成,空间聚集体的规模和数量同时增长。③ 2001年以来,皖南进入空间集聚体涌现阶段,主体之间的非线性相互作用加强,多种新兴发展要素涌现;新兴发展要素和传统发展要素共同催生了文化旅游、度假旅游和乡村旅游等新的旅游产品,推动皖南旅游区空间演化发展。未来,旅游需求的多元化将推动皖南旅游资源的多样化、全域化的利用,文化性、生态性、乡村性的观光和休闲度假旅游将成为皖南旅游发展主流方向;高速铁路、高速公路等快速交通网的建设将加强皖南与长三角地区的联系,皖南将以全域旅游方式,整体融入长三角区域旅游发展之中,成为长三角旅游区重要的组成部分。  相似文献   

Integrating algebraic multigrid method in spatial aggregation of massive trajectory data     

Siying Wang  Yunyan Du  Chen Jia  Meng Bian 《International journal of geographical information science》2018,32(12):2477-2496

The advanced technologies in location-based services and telecom have yield large volumes of trajectory data. Understanding these data effectively requires intuitive yet accurate visual analysis. The visual analysis of massive trajectory data is challenged by the numerous interactions among different locations, which cause massive clutter. This paper presents a new methodology for visual analysis by integrating algebraic multigrid (AMG) method in data aggregation. The non-parametric method helps to build a multi-layer node representation from a graph which is extracted from trajectory data. The comparison with AMG and other methods shows that AMG method is more advanced in both the spatial representation and the importance of nodes. The new method is tested with real-world dataset of cell-phone signalling records in Beijing. The results show that our method is suitable for processing and creating abstraction of massive trajectory dataset, revealing inherent patterns and creating intuitive and vivid flow maps.  相似文献   

The Research and Practice of Professional Knowledge Sharing and Service: A Case Study of the Geography,Resources,and Ecology Knowledge Service System     

CHEN Zugang  SUN Jiulin  YANG Yaping 《资源与生态学报(英文版)》2018,9(2):218-226

Knowledge Sharing and Service is one effective way to eliminate knowledge poverty and promote social development. Existing knowledge sharing and service is mainly provided in some organizations or specific social groups. Besides, a knowledge sharing and service system about geography, natural resources and ecology has not been reported. We proposed a public welfare professional knowledge-sharing and service platform for all members of society in geography, natural resources and ecology. The construction of a knowledge-sharing and service platform is based on five aspects of work: analysis of user requirements, setting standards and drafting policies, aggregating knowledge resources, the technical realization and the maintenance of service. Knowledge resources can be aggregated by using a “two-step” strategy. A knowledge-sharing and service system can be implemented by using “four-tier” structures that are comprised of resources, resource access, application and service, based on the Hadoop-distributed cluster architecture. It has been proven that adhering to the idea of co-building and co-sharing, and using the mechanism of “payment is equal to benefit” can effectively promote the gathering of knowledge resources, and arouse the enthusiasm of all members of society to participate in knowledge sharing and service, to achieve the objective of narrowing the knowledge gap between social groups.  相似文献   

尼日利亚奥贡广东自贸区发展历程与产业聚集研究   总被引：3，自引：2，他引：1  

孟广文  王春智  杜明明  王继光  赵钏  鲁笑男  王红梅 《地理科学》2018,38(5):727-736

利用贸易结合度指数分析中尼双方相互贸易依赖程度,总结中国对尼贸易与投资特征;在回顾尼日利亚奥贡广东自贸区的发展历程基础上,利用EG指数分析园区产业聚集程度,得出了园区多数产业集聚度较高,并符合尼日利亚鼓励先锋行业要求的结果;通过对结果的分析与讨论,总结目前园区在产业、基础设施、东道国政治经济环境等方面面临的挑战;最后从政府与企业两方面提出园区产业优化与发展的建议。  相似文献   

A method for the identification and characterization of clusters of schools along the transect lines of fisheries-acoustic surveys   总被引：1，自引：1，他引：0  

Petitgas  Pierre 《ICES Journal of Marine Science》2003,60(4):872-884

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镁铁—超镁铁质岩浆中铂族元素的富集机理：综述与实例     

王焰  魏博  陈晨  白玉颖 《地质学报》2023,97(11):3622-3636

目前陆地上可利用的铂族元素(PGE)资源主要来自与镁铁—超镁铁质岩浆密切相关的岩浆硫化物矿床。岩浆硫化物矿床成矿理论关注的一个重要问题就是镁铁—超镁铁质岩浆中PGE的富集机理。经典成矿理论认为,由于PGE在平衡的硫化物熔体与硅酸盐熔体之间具有极高的分配系数(105～106),PGE富集成矿主要与成矿体系中硅酸盐熔体与硫化物熔体的质量比有关(R-factor)。但是近些年来,许多新的实验岩石学结果和天然矿石样品纳米尺度PGE赋存状态的观测结果对这一经典理论提出了挑战。本文列举了一些相关的研究实例,显示硅酸盐熔体中的PGE纳米颗粒可以被硫化物或铬铁矿机械捕获、并通过定向附着生长、聚集、粗化和融合,最终形成纳米颗粒集合体和纳米合金。另外,岩浆中半金属元素(TABS,即Te、As、Bi、Sb、Sn)和Se可以与PGE优先形成各种互化物,从而富集于砷化物、铋化物、碲化物或硒化物中,而非硫化物中。因此,镁铁—超镁铁质岩浆体系中PGE的富集可能不仅受其在硫化物熔体中极高的分配系数控制,一些物理过程导致的PGE分配以及半金属元素对PGE的富集作用也不容忽视。由于矿石中的铂族矿物一般为纳—微米级,采用聚...  相似文献   

The study on county accessibility in China: Characteristics and effects on population agglomeration     

WANG Zhenbo  XU Jiangang  FANG Chuanglin  XU Lu  QI Yi 《地理学报》2011,21(1):18-34

This paper calculated spatial accessibility of all counties (city, urban district) in China with cost weighted distance method. Region divisions of county accessibility were conducted, and relation of traffic accessibility and population aggregation was discussed in this paper. The results indicated that county accessibility in China had mainly low values and a distribution structure of circle layer and reverse-to-natural gradient. There was an obvious correlation between county accessibility and population density in China. With these analyses, inner mechanisms of population migration in different traffic conditions and region types were revealed, and can provide useful proposals to regional planning, traffic planning and smart distribution of people in China.  相似文献   

On the effects of triangulated terrain resolution on distributed hydrologic model response     

Enrique R. Vivoni  Valeriy Y. Ivanov  Rafael L. Bras  Dara Entekhabi 《水文研究》2005,19(11):2101-2122

Distributed hydrologic models based on triangulated irregular networks (TIN) provide a means for computational efficiency in small to large‐scale watershed modelling through an adaptive, multiple resolution representation of complex basin topography. Despite previous research with TIN‐based hydrology models, the effect of triangulated terrain resolution on basin hydrologic response has received surprisingly little attention. Evaluating the impact of adaptive gridding on hydrologic response is important for determining the level of detail required in a terrain model. In this study, we address the spatial sensitivity of the TIN‐based Real‐time Integrated Basin Simulator (tRIBS) in order to assess the variability in the basin‐averaged and distributed hydrologic response (water balance, runoff mechanisms, surface saturation, groundwater dynamics) with respect to changes in topographic resolution. Prior to hydrologic simulations, we describe the generation of TIN models that effectively capture topographic and hydrographic variability from grid digital elevation models. In addition, we discuss the sampling methods and performance metrics utilized in the spatial aggregation of triangulated terrain models. For a 64 km² catchment in northeastern Oklahoma, we conduct a multiple resolution validation experiment by utilizing the tRIBS model over a wide range of spatial aggregation levels. Hydrologic performance is assessed as a function of the terrain resolution, with the variability in basin response attributed to variations in the coupled surface–subsurface dynamics. In particular, resolving the near‐stream, variable source area is found to be a key determinant of model behaviour as it controls the dynamic saturation pattern and its effect on rainfall partitioning. A relationship between the hydrologic sensitivity to resolution and the spatial aggregation of terrain attributes is presented as an effective means for selecting the model resolution. Finally, the study highlights the important effects of terrain resolution on distributed hydrologic model response and provides insight into the multiple resolution calibration and validation of TIN‐based hydrology models. Copyright © 2005 John Wiley & Sons, Ltd.  相似文献   

创新地理信息服务模式,打造网络地理信息服务民族优秀品牌   总被引：2，自引：0，他引：2  

李志刚 《测绘软科学研究》2011,(4):7-9,19

＂天地图＂是国家地理信息公共服务平台建设取得的重要成果。它的开通标志着国家测绘地理信息局在转变测绘服务方式、提升测绘服务能力、推进地理信息产业发展方面迈出了至关重要的一步。＂天地图＂的建设采用了集成技术创新、服务模式创新、组织实施模式创新等策略,有效地利用、集成和优化各种资源,产生了集成效应。＂天地图＂刚刚起步,距满足用户需求还有很大距离。国家基础地理信息中心将在国家测绘地理信息局的领导下,大力丰富信息资源、提升服务能力,推进社会化应用,力争早日将＂天地图＂打造成为具有国际影响力的民族品牌。  相似文献