“一带一路”沿线国家石油资源流动类型演变     

孙琪  赵媛  张新林  夏四友 《世界地理研究》2020,29(2):337-345

综合运用石油自给率、流动比率等方法，以“一带一路”沿线国家为研究对象，对1995—2014年各国石油资源流动类型时空演变进行研究。结果表明：1）1995—2014年石油净补给型国家数量较为稳定，无产型或低产型国家的石油贸易倾向变化相对较小；基本自给型国家数量占比最大，1995年占比1/2，其余四个年份占比稳定在1/3；净支出型国家数量显著增加，至2014年其中有5个国家保持不变，表明这些国家的石油产量具有较大的优势。2）1995年和2014年汇地国家均为39个国家，其中有34个国家一直保持汇地职能，空间分布上呈东多西少，南多北少，东西分化以西亚、中亚、东欧为界；有14个国家一直保持源地职能，其空间分布格局与汇地相应，西多东少，南多北少，主要分布于西亚、东欧及中亚；交流地数量较少，呈分散分布，且分布地不稳定。3）从数量变化来看，研究期内汇地略有增加，源地略有减少，交流地略有增加；“一带一路”源地总出口量与汇地总进口量的比呈逐年降低趋势。  相似文献   

“一带一路”背景下的中国与巴基斯坦的贸易关系演进及其影响因素     

宋周莺  祝巧玲 《地理科学进展》2020,39(11):1785-1797

中巴经济走廊是“一带一路”6大经济走廊之一,而贸易畅通是“一带一路”建设的核心环节。研究中巴贸易关系演变及其影响因素、分析其贸易潜力,对推进“一带一路”建设具有重要的示范作用。论文从中巴贸易发展态势、商品结构、空间格局等方面揭示中巴贸易关系,运用随机前沿引力模型分析中巴贸易关系的主要影响因素、并探析其发展潜力,以期为推进中巴经济走廊建设提供科学支撑。研究发现：① 中巴贸易发展迅速,中对巴贸易顺差持续扩大;中国主要出口机械及电气设备等资本密集型产品,主要进口纺织原料及纺织制品等初级产品和劳动密集型产品。② 中国各省份与巴基斯坦的贸易合作存在明显的空间差异,东部沿海省份与巴贸易联系较紧密,西部各省份除新疆外与巴基斯坦贸易额均较小。③ 中国多数省份对巴贸易商品结构发生显著变动,其中,新疆、山东等进出口商品结构多元的省份的变动相对较小。④ 中国各省份的经济发展水平和市场规模对中巴贸易拉动较强;海运距离对中巴贸易规模有显著的负向影响;领土接壤为中巴组织边境贸易提供了良好条件;铁路和水运口岸的建设对中巴贸易具有积极影响。⑤ 中国各省份与巴基斯坦均有较大贸易潜力,内蒙古、云南、广西、陕西等省份的合作潜力更明显。  相似文献   

Analysis of city centrality based on entropy weight TOPSIS and population mobility:A case study of cities in the Yangtze River Economic Belt     

罗静  陈四云  孙璇  朱媛媛  曾菊新  陈广平 《地理学报(英文版)》2020,30(4):515-534

Based on statistical data and population flow data for 2016,and using entropy weight TOPSIS and the obstacle degree model,the centrality of cities in the Yangtze River Economic Belt(YREB)together with the factors influencing centrality were measured.In addition,data for the population flow were used to analyze the relationships between cities and to verify centrality.The results showed that:(1)The pattern of centrality conforms closely to the pole-axis theory and the central geography theory.Two axes,corresponding to the Yangtze River and the Shanghai-Kunming railway line,interconnect cities of different classes.On the whole,the downstream cities have higher centrality,well-defined gradients and better development of city infrastructure compared with cities in the middle and upper reaches.(2)The economic scale and size of the population play a fundamental role in the centrality of cities,and other factors reflect differences due to different city classes.For most of the coastal cities or the capital cities in the central and western regions,factors that require long-term development such as industrial facilities,consumption,research and education provide the main competitive advantages.For cities that are lagging behind in development,transportation facilities,construction of infrastructure and fixed asset investment have become the main methods to achieve development and enhance competitiveness.(3)The mobility of city populations has a significant correlation with the centrality score,the correlation coefficients for the relationships between population mobility and centrality are all greater than 0.86(P<0.01).The population flow is mainly between high-class cities,or high-class and low-class cities,reflecting the high centrality and huge radiating effects of high-class cities.Furthermore,the cities in the YREB are closely linked to Guangdong and Beijing,reflecting the dominant economic status of Guangdong with its geographical proximity to the YREB and Beijing's enormous influence as the national political and cultural center,respectively.  相似文献   

Cryospheric Changes and Their Impacts on Water Resources in the Belt and Road Regions     

Shichang Kang  Wanqin Guo  Tonghua Wu  Xinyue Zhong  Rensheng Chen  Min Xu  Jinlei Chen  Ruimin Yang 《地球科学进展》2020,35(1):1-17

“Belt and Road” regions include Asia, Europe and eastern and northern Africa, with a wide spatial distribution. The cryosphere is undergoing rapid changes in the Belt and Road regions with global warming, and has an important impact on water resources, ecosystems and Arctic waterways in these regions. This article reviewed recent cryospheric changes and associated impacts on water resources in the Belt and Road regions during the last decades. The main cognitions are as follows: \mathrm{①} Most glaciers are shrinking and glacier mass balances are most negative, but there are regional differences in the changes of glaciers. \mathrm{②} Global temperature rise has resulted in permafrost degradation, including a rise in permafrost temperature and decreasing permafrost thickness as well as an increase in active layer thickness. \mathrm{③} There is a significant decrease in snow cover extent and an increase in snow depth. Snow cover duration has shortened, the onset of snow cover has delayed, and the end of snow cover has advanced. However, there are still obvious regional differences in the changes of snow cover. \mathrm{④} Arctic sea ice has declined precipitously in both extent and thickness in summer, and multi-year sea ice has decreased，indicating the precipitous retreat of sea ice. The freeze-up date of some lakes has been delayed, the break-up date has advanced, and the ice cover duration of river/lake ice has significantly shortened. \mathrm{⑤} Glacial runoff has increased significantly in China. Snowmelt and permafrost degradation have also increased the basin runoff, which indicates the important impact of cryospheric changes on runoff. This study will provide a baseline and important scientific support for addressing climate change and regional sustainable development.  相似文献   

“一带一路”背景下中国国际航空网络的空间格局及演变     

杜方叶  王姣娥  谢家昊  杜德林 《地理科学进展》2019,38(7):963-972

2013年“一带一路”倡议提出将设施联通作为合作战略重点之一,航空网络作为设施联通的重要组成部分,其地位提升到新的高度。为评估“一带一路”倡议的提出对中国国际航空网络的影响,论文选取了2013年和2018年数据,从国际航线、国际航班以及通航城市3个方面分析“一带一路”倡议提出以来中国国际航空网络的空间格局及其演变特征。研究结果表明：① 整体上来看,“一带一路”倡议并未从根本上改变中国国际航空网络的空间格局,仍以东亚、东南亚、美国以及俄罗斯等地区和国家为主,5 a来其变化主要集中在进一步加深与已有城市的联系;② 从沿线国家来看,一带一路”倡议增加了与中国直接通航的沿线国家数量,并提升了沿线国家在中国国际航空网络中的地位;③ 越来越多的境内城市参与到中国对外开放格局中,且航线和航班在北京、上海、广州的聚集程度下降,而其他城市的航线和航班占比逐渐增加。  相似文献   

东昆仑金水口地区格林威尔期超高温麻粒岩   总被引：1，自引：1，他引：0  

何凡  宋述光 《岩石学报》2020,36(4):1030-1040

格林威尔期构造事件是了解罗迪尼亚超大陆形成的关键。本文报道了东昆仑造山带东段金水口地区古生代花岗岩中新发现二辉麻粒岩包体,其峰期变质矿物组合为单斜辉石+紫苏辉石+钙长石+石英+磁铁矿。通过锆石U-Pb测年,我们确定二辉麻粒岩样品的峰期变质年龄为995±34Ma,并受到泥盆纪(～417Ma)构造热事件的叠加改造。利用单斜辉石-斜方辉石温压计估算出该区二辉麻粒岩变质峰期温度867～1079℃,压力46～89kbar,属于低压超高温变质的温压范围,可能形成于高地温梯度的岛弧环境。该二辉麻粒岩是首次在东昆仑地区发现的格林威尔期超高温麻粒岩,代表罗迪尼亚超大陆汇聚过程中低压高温变质的产物。该发现对了解东昆仑造山带前寒武纪基底的构造属性和起源有重要意义。  相似文献   

新疆图拉尔根镁铁-超镁铁质杂岩体镍铜钴成矿岩浆作用过程:流体化学与碳同位素组成制约     

张铭杰  班舒悦  李思奥  宋哲  仇哲  李立武  惠卫东  李中平 《岩石学报》2020,36(12):3673-3682

东天山造山带的图拉尔根镁铁-超镁铁杂岩体为一个早古生代长期活动的幔源岩浆通道，大型铜镍钴硫化物矿体赋存于Ⅰ号超镁铁质岩体的顶部，不同类型岩石中辉石矿物的流体挥发份化学组成以H₂O为主（平均91%，5400.4mm³/g），其次为H₂（2.0%）、H₂S（2.3%）和CO₂（2.1%）；赋矿角闪橄榄岩中CO₂和H₂S含量最高，辉长岩中流体挥发份含量低于辉石橄榄岩和橄榄辉石岩等岩浆早期结晶的岩石。CO₂和CH₄的δ¹³C值位于地壳与甲烷氧化的范围内，甲烷同系物的碳同位素组成具有正序分布模式，部分样品（TLG512）释出的CH₄和C₂H₆具有较重的δ¹³C值和反序分布特征。表明I号岩体不同类型岩石可能是不同期次岩浆活动的产物，成矿岩浆具有富H₂O和H₂S的特征，可能起源于被流体交代的亏损地幔源区，混染壳源组分可能为俯冲板片来源蚀变沉积有机质组分。  相似文献   

鄂尔多斯地块—扬子地块深部电性结构特征及其动力学意义     

吕宏斌  叶高峰  金胜  魏文博  董浩  张乐天  谢成良  尹曜田 《地质论评》2020,66(4):813-828

位于青藏高原东北缘的秦岭造山带在大地构造上南接扬子地块、北接华北地块,是特提斯构造域和古亚洲洋构造域的转换带。本文基于对一条起始于扬子地块,穿过秦岭造山带和鄂尔多斯地块,到达河套地堑的南北向大地电磁测深剖面的研究,探讨秦岭造山带和其北侧的鄂尔多斯地块、南侧的扬子地块之间的接触关系,以及青藏高原物质东北向逃逸等地学问题。对实测数据进行了张量阻抗分解和维性分析等工作,并对剖面进行了二维反演,获得岩石圈电性结构模型。根据电阻率模型认为:在秦岭造山带北部发现大规模"瓶颈状"分布的低阻异常体(C2),可能为华北、华南地块双向俯冲前缘地幔物质的上涌通道,或者是青藏高原中、下地壳物质沿秦岭造山带中构造薄弱位置向东逃逸的通道;在秦岭造山带和大巴山弧形带边界处发现南倾的低阻异常(C1),解释为大巴山弧形带北缘的逆冲断裂在电性上的反映;电性结构模型中,扬子地块高阻异常体(R2、R3和R4)向北倾斜至秦岭造山带下方,而北部鄂尔多斯地块的高阻异常体(R5和R6)向南倾斜至秦岭造山带下方;高阻异常通常被认为是稳定岩石圈的反映,据此推断这两组相向俯冲至秦岭造山带下方的高阻异常是华北地块和扬子地块向秦岭造山带下方汇聚的电性结构探测依据;鄂尔多斯地块南、北电性差异较大,北部中、下地壳大规模分布电阻率值在3～100Ω·m之间的低阻异常体,可能为地幔上涌导致的局部熔融或含盐流体共同作用的结果。  相似文献   

Effects of heavy metal pollution on farmland soils and crops: A case study of the Xiaoqinling Gold Belt,China   总被引：1，自引：0，他引：1  

《China Geology》2020,3(3):402-410

This paper focuses on the heavy metal enrichment and heavy metal pollution degree associated with mining activities in some crops and the soils of different parent materials in the Xiaoqinling Gold Belt. According to the geochemical analysis results of the soils observed in the gold belt, the soils are most highly enriched in Pb, followed by Cr, Cu, and Zn. Furthermore, they are relatively poor in Hg, Cd, and As. It is also shown that the heavy metals in all kinds of soils have the same geochemical characteristics in the gold belt. As for the crops (such as corn and wheat) in the gold belt, Zn and Cu are the most abundant elements, followed by Pb and Cr. Meanwhile, Hg, Cd, and As were found to have relatively low concentrations in the crops. The heavy metals in wheat and corn have the same geochemical characteristics in the gold belt in general. Compared to the aeolian loess soils and the crops therein, heavy metals are more enriched in diluvial and alluvial soils and the crops therein. As shown by relevant studies, the Hg, Pb, Cd, Cu, and Zn pollution are mainly caused by mining activities. Corn and wheat in the gold belt have a high tendency of risk exposure to heavy metal pollution since they are mostly affected by mining activities and feature high background values of heavy metal concentrations. Furthermore, wheat is more liable to be enriched in heavy metals than corn is grown in all types of soils. The Hg pollution in soils leads to Hg accumulation, increasing the risk of Hg uptake in crops, and further affecting human health. This study will provide a scientific basis for the control and management of heavy metals in farmland soils of mining areas.  相似文献   

中国-丝路国家基础设施连通性评估方法与格局     

王成金  陈沛然  王姣娥  李娜 《地理研究》2020,39(12):2685-2704

基础设施互联互通是不同区域之间空间网络形成的支撑,对区际生产要素流动、市场融合和资源配置具有重要作用,也是“一带一路”建设的重点内容和前提条件。立足于综合基础设施网络,以“一带一路”沿线国家/地区为分析地域,设计数理模型,评价了中国与沿线国家的基础设施网络连通性,考察其基本特征与空间格局,然后分别从铁路、公路、航运、通讯、能源等各种基础设施方式的视角,分析了不同基础设施网络的互联互通水平,探讨了基础设施连通的类型分异及其主导因素,凝练基础设施连通的空间模式。主要结论如下：① 从海陆属性来看,岛屿型国家与中国设施连通性最高,其次为综合型国家,内陆型国家最低。对国际区域而言,俄蒙和东南亚地区与中国的设施连通性最高,中东欧地区连通性最低。从国家尺度来看,俄罗斯和越南是与中国设施连通水平最高的国家,巴勒斯坦、东帝汶等5个国家与中国尚未形成设施连通性。从连通方式的构成来看,航运网络的连通性最高,其次为航空和光缆。② 空间距离、连通方式和重大交通走廊共同主导了设施连通性的类型分异。③ “一带一路”沿线国家/地区与中国的设施连通形成了四种典型模式,包括海陆融合型外缘连通模式、陆路通道直接连通模式、陆心内生性低水平连通模式、远距离不均衡连通模式。  相似文献