Population,urbanization and economic scenarios over the Belt and Road region under the Shared Socioeconomic Pathways   总被引：1，自引：0，他引：1  

Jing  Cheng  Tao  Hui  Jiang  Tong  Wang  Yanjun  Zhai  Jianqing  Cao  Lige  Su  Buda 《地理学报(英文版)》2020,30(1):68-84

The countries throughout the Belt and Road region account for more than 60% of the world's population and half of the global economy. Future changes in this area will have significant influences on the global economic growth, industrial structure and resource allocation. In this study, the proportion of the urban population to the total population and the gross domestic product were used to represent the levels of urbanization and economic development, respectively. The population, urbanization and economic levels of the Belt and Road countries for 2020–2050 were projected under the framework of the IPCC's shared socioeconomic pathways(SSPs), and the following conclusions are drawn.(1) The population, urbanization and economic levels in the Belt and Road region will likely increase under all five pathways. The population will increase by 2%–8%/10 a during 2020–2050 and reach 5.0–6.0 billion in 2050. Meanwhile, the urbanization rate will increase by 1.4%–7.5%/10 a and reach 49%–75%. The GDP will increase by 17%–34%/10 a and reach 134–243 trillion USD.(2) Large differences will appear under different scenarios. The SSP1 and SSP5 pathways demonstrate relatively high urbanization and economic levels, but the population size is comparatively smaller; SSP3 shows the opposite trend. Meanwhile, the economy develops slowly under SSP4, but it has a relatively high urbanization level, while SSP2 exhibits an intermediate trend.(3) In 2050, the population will increase relative to 2016 in most countries, and population size in the fastest growing country in Central Asia and the Middle East countries will be more than double. Urbanization will develop rapidly in South Asia, West Asia and Central Asia, and will increase by more than 150% in the fastest growing countries. The economy will grow fastest in South Asia, Southeast Asia and West Asia, and increase by more than 10 times in some counties with rapid economic development.  相似文献   

The effect of heterogeneous stress and strain on metamorphic fluid flow,Mary Kathleen,Australia, and a model for large-scale fluid circulation *     

N. H. S. OLIVER  R. K. VALENTA  V. J. WALL 《Journal of Metamorphic Geology》1990,8(3):311-331

In the Proterozoic Mary Kathleen Fold Belt, northern Australia, infiltration of large volumes of externally derived fluid occurred synchronously with regional amphibolite-facies metamorphism and deformation. This paper develops a model of structurally controlled fluid migration by comparing the distribution of fossil fluid pathways with the inferred stress and strain patterns during the deformation. Intense fluid flow was localized within strong, relatively brittle meta-intrusive bodies, and in discrete, veined, brecciated and altered zones around their margins. In metasediments folded in a ductile manner outside these areas, fluid infiltration was negligible. The direct correlation between structural styles and the magnitude of veining and metasomatism suggests control of permeability enhancement, and hence fluid flow, by deformation. Finite difference modelling of a strong body in a weaker matrix has been used to evaluate the variation of stresses during the deformation, from which it is clear that stress and strain heterogeneities have systematically influenced the development and maintenance of metamorphic fluid pathways. Particular regions in which mean stress may be significantly lower than the average lithostatic pressures include the ‘strain shadow’zones adjacent to the strong bodies, other dilatant zones around the bodies, and the bodies themselves. This geometry is favourable not only for localized brittle deformation under amphilobite facies conditions, but also for focused fluid flow in the low mean stress regions, as evidenced by the abundance of veins. Fluid access through these metamorphic aquifers occurred during tensile failure episodes, with particularly large dilations and decimetre-scale veining in areas of strain incompatibility. It appears likely that fluid circulated many times through the Fold Belt, with flow concentrated in the metamorphic aquifers. A model is developed that explains both the structurally focused fluid flow and the postulated multi-pass recirculation by dilatancy pumping, the ‘pump engines’comprising the low mean stress zones.  相似文献   

今天的中国为什么比任何时候都需要世界地理学   总被引：3，自引：2，他引：3  

秦大河  张国友  宋长青  金凤君  薛德升  杜德斌  陆玉麒  苗长虹  葛岳静  吴志峰  刘建忠  张振克  刘云刚  宁越敏  效存德  王荣成  陈俊华  李娟  胡志丁 《世界地理研究》2020,29(1):1-7

世界地理作为中国地理学的重要分支学科，特指研究中国以外区域或国家的地理学科，是中国特有的学科分类现象。中国地理学的这种内外有别的思想对世界地理发展危害甚大，至今都难以消弭。忽视世界地理研究，就会有只见树木、不见森林之虞。为了贯彻落实党的“十九大”精神，繁荣探索新型科研组织机制，打造一流世界地理学科，服务国家重大国际战略需求，来自国内高校、科研院所的百余人齐聚一堂，探讨中国世界地理学科发展之路。与会专家一致认为：地理学是国家发展的法宝，是立国之本。当前世界政治经济格局加速重构，为中国地理学发展带来了前所未有的历史机遇，也赋予地理学特别是世界地理学学科新的重大历史使命。为此，须充分发挥地理学科的优势和特长，紧跟国家和世界发展大势，树立全球眼光，面向国家重大战略需求，把自然与人文结合起来，面向可持续发展，团结国内各相关单位，进行跨学科研究，提升世界地理学科为二级学科，构建具有中国特色的世界地理学理论体系、逻辑框架和学科范式，提升中国地理学科，特别是世界地理学科服务国家和地方发展的能力。  相似文献   

The Belt and Road: Geographical pattern and regional risks     

Wu  Shaohong  Liu  Lulu  Liu  Yanhua  Gao  Jiangbo  Dai  Erfu  Feng  Aiqing  Wang  Wentao 《地理学报(英文版)》2019,29(4):483-495

Journal of Geographical Sciences - Building the Belt and Road is initiatives of China to promote win-win international cooperation in the new era, aiming at green, health, intellect and peace and...  相似文献   

Low-pressure regional metamorphism in the Omeo Metamorphic Complex, Victoria, Australia     

V. J. MORAND 《Journal of Metamorphic Geology》1990,8(1):1-12

The Omeo Metamorphic Complex forms the southern end of the Wagga Metamorphic Belt, which is the main locus of Palaeozoic low-pressure metamorphism in the Lachlan Fold Belt, south-eastern Australia. It comprises metamorphosed Ordovician quartz-rich turbidites originally derived from Precambrian cratonic rocks. Prograde regional metamorphism occurred in the early Silurian, very soon after sedimentation had ceased. The sequence of metamorphic zones, with increasing grade, is: chlorite, biotite, cordierite, andalusite–K-feldspar and sillimanite–K-feldspar. Migmatites occur in the sillimanite–K-feldspar zone, but large bodies of S-type granite were derived from rocks underlying the exposed Ordovician sequence. P and T estimates for the highest grade rocks are T = 700°C and P = 3.5 kbar, indicating a very high P–T gradient of 65°C/km.
The high heat flow during prograde metamorphism probably resulted from a combination of a thermal anomaly persisting from a pre-metamorphic back-arc basin environment, and intrusion of hot, mantle-derived magmas into the lower and middle crust.
Regional retrograde metamorphism coincided with a general reheating of the crust in the Siluro-Devonian, accompanied by intrusion of many I-type plutons and resetting of the K–Ar dates of some earlier plutons. The Omeo Metamorphic Complex was exposed to erosion at this time.  相似文献   

Unpairing metamorphic belts: P–T paths and a tectonic model for the Ryoke Belt, southwest Japan     

MICHAEL BROWN 《Journal of Metamorphic Geology》1998,16(1):3-22

Southwest Japan is divided into Outer and Inner Zones by the Median Tectonic Line (MTL), a major transcurrent fault. The Outer Zone is composed of the Sambagawa (high-pressure intermediate or high P/T type metamorphism), Chichibu and Shimanto Belts. In the Inner Zone, the Ryoke Belt (andalusite– sillimanite or low P/T type metamorphism) was developed mainly within a Jurassic accretionary complex. This spatial relationship between high P/T type and low P/T type metamorphic belts led Miyashiro to the idea that metamorphic belts were developed as ‘paired’ systems. Textural relationships and petrogenetically significant mineral assemblages in pelites from the Ryoke Belt imply peak P–T conditions of ≈5 kbar and up to 850 °C in migmatitic garnet–cordierite rocks from the highest-grade metamorphic zone. It is likely that the thermal anomaly responsible for metamorphism of the Ryoke Belt was related to a segment of the Farallon–Izanagi Ridge as it subducted under the eastern margin of the Asian continent during the Cretaceous. The sequence of mineral assemblages developed in pelites implies a metamorphic field gradient with shallow dP/dT slope, inferred to have been generated by a nested set of hairpin-like ‘clockwise’P–T paths. These P–T paths are characterized by limited prograde thickening, minor decompression at peak-T , and near-isobaric cooling, features that may be typical of P–T paths in low P/T type metamorphic belts caused by ridge subduction. A ridge subduction model for the Ryoke Belt implies that juxtaposition of the high-P/T metamorphic rocks of the Sambagawa Belt against it was a result of terrane amalgamation. Belt-parallel ductile stretching, recorded as syn-metamorphic, predominantly constrictional strain in both Ryoke and Sambagawa Belt rocks, and substantial sinistral displacement on the MTL are consistent with left-lateral oblique convergence. Diachroneity in fast cooling of the Ryoke Belt is implied by extant thermochronological data, and is inferred to relate to progressive SW to NE docking of the Sambagawa Belt. Thus, an alternative interpretation of ‘paired’ metamorphic belts in Japan is that they represent laterally contemporaneous terranes, rather than outboard and inboard components of a trench/arc ‘paired’ system. Amalgamation of laterally contemporaneous terranes during large translations of forearcs along continental margins may explain other examples of ‘paired’ metamorphic belts in the geological record.  相似文献   

Production of trans-Neptunian binaries through chaos-assisted capture     

Ernestine A. Lee  Sergey A. Astakhov  David Farrelly 《Monthly notices of the Royal Astronomical Society》2007,379(1):229-246

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Millisecond dips in the RXTE/PCA light curve of Sco X-1 and trans-Neptunian object occultation     

Hsiang-Kuang Chang  Jau-Shian Liang  Chih-Yuan Liu  Sun-Kun King 《Monthly notices of the Royal Astronomical Society》2007,378(4):1287-1297

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中资企业研发国际化研究述评   总被引：2，自引：0，他引：2  

司月芳  延留霞  张翌 《地理研究》2020,39(5):1056-1069

中资跨国公司研发国际化服务于中国"全面提高开放型经济水平"和"创新驱动发展战略"两大政策方针,是重要的地理学研究前沿。本文系统评述了中资企业研发国际化的定义、理论基础、研究内容、数据和方法,发现基于发达国家跨国公司实践建立起的经典理论还不足以解释中资企业行为。相比于快速发展的中资企业跨国研发活动行为,现有的实证研究存在着研究视角、内容和方法的局限,未来应发扬地理学多尺度研究的优势,综合分析企业研发国际化与区域发展的互动机制;发扬地理学重视区域差异的优势,开展在"一带一路"国家中资企业研发国际化的异质性研究;发扬地理学重视实地调研的优势,综合多种方法和数据的相互印证。  相似文献   

长江经济带城市群要素集聚能力差异的比较研究   总被引：1，自引：2，他引：1  

郭庆宾  骆康  刘承良 《地理科学进展》2020,39(4):542-552

城市群作为当前区域发展的主要空间载体,在区域发展竞争中扮演着越来越重要的角色。论文结合互联网大数据抓取等手段,以长江经济带5个城市群为研究对象,对城市群间要素集聚能力差异进行比较研究,发现：① 长江经济带城市群间要素集聚能力差异与长江经济带社会经济发展的区域差异相吻合,城市群要素集聚格局呈现出由东向西梯度衰减的分布特征;② 城际层面要素集聚能力差异的两极分化现象显著,以城市群首位城市为中心的要素集聚“核心—边缘”空间结构特征较为鲜明;③ 长江经济带城市群内科技创新、对外开放、金融等要素的集聚格局具有明显的差异分化和集聚分布指向特征;④ 长江经济带城市(群)要素集聚能力等级规模结构分布总体符合位序-规模法则,可分为“均衡型”和“离散型”2种类型,首位城市要素集聚首位度随城市群要素集聚能力高低呈现出“两端高、中间低”的特征。  相似文献