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1.
“一带一路”建设研究进展   总被引:25,自引:6,他引:19  
“一带一路”经历了从中国倡议到国际共识的巨大转变,正在成为世界上越来越多国家和政治领袖们探索全球经济治理新模式的平台。伴随这种转变以及“一带一路”建设所取得的成就,“一带一路”研究已经深入到除了基础科学领域外的几乎所有学科。本文根据中国知网(CNKI)数据分析了4年多来“一带一路”研究文献的特征,而后总结了与地理学密切相关的“一带一路”核心议题的研究进展。研究发现:① 自2014年以来“一带一路”研究发文量迅速上升,由2014年的1000多篇飙升到2017年的20000多篇;② 文献比较庞杂,以宏观性、战略性和一般性文献为主,舆论性很高,基于深入研究的高水平学术文献少,还不能很好地支撑“一带一路”建设;③ 对外直接投资、互联互通、“走出去”、全球化、全球治理、命运共同体、人民币国际化等得到的关注较多;④ 地理学在“一带一路”的战略内涵和理论构建、地缘政治经济分析、“中欧班列”、海上航运战略支点、海外投资模式、经贸格局及其经济影响、资源环境问题等方面研究较为深入。最后,本文呼吁加强“一带一路”的理论建构以及建设机制和国别研究,并积极开展中外学者之间“一带一路”研究对话以及合作研究。  相似文献   
2.
“ 中欧班列”陆路运输腹地范围测算与枢纽识别   总被引:4,自引:0,他引:4  
王姣娥  焦敬娟  景悦  马丽 《地理科学进展》2017,36(11):1332-1339
自“一带一路”战略实施以来,中国各地政府大力推进中欧国际班列运输,试图改变传统的对外贸易运输体系,强化提升新欧亚大陆桥运输作用。然而,设施联通、运输价格、货源及复杂的地缘政治环境等问题仍然是制约中欧班列发展的重要因素。为此,本文在分析“中欧班列”运营现状及存在问题基础上,提出实现其高频率常态运营的“轴-辐”运输组织模式。通过构建高、中、低三种运价方案,利用距离—经济成本分析法划分“中欧班列”主要出境口岸的经济腹地范围;并综合考虑各城市的铁路技术指标、集疏运能力和货源—成本等因素,从全国尺度识别出“中欧班列”组织的枢纽城市。  相似文献   
3.
We have analyzed spectra of CO recorded with the instrument PFS onboard Mars Express in the (1-0) band. The dataset we used ranges in time from January until June 2004 (LS=331°.17 until LS=51°.61; end of Mars Year 26, beginning of Mars Year 27). The aim of this work was to determine the amplitude of the CO mixing ratio departures from the mean globally averaged value currently admitted (8±3×10-4) [Kaplan, L.D., Connes, J., Connes, P., 1969. Carbon monoxide in the martian atmosphere. Astron. J. 157, L187-L192] as a function of season, local time and location on the planet. We therefore processed the data from 90 calibrated orbits. The globally averaged CO mixing ratio value we derive from our dataset, 11.1×10-4, is compatible with the range found by Kaplan et al. [1969. Carbon monoxide in the martian atmosphere. Astron. J. 157, L187-L192], although somewhat higher than the “standard” value. However, the CO mixing ratio we retrieve exhibits large variations (roughly between 3×10-4 and 18×10-4). Such relative variations have been used on a statistical basis to derive main trends as a function of latitude for three LS ranges: 331-360°, 0-30° and 30-52°. For the first LS range, we seem to have an enhancement of the CO mixing ratio towards the northern latitudes, probably linked to the CO2 condensation in winter on the north polar cap. The situation for the two other LS ranges is not so clear, mainly as we lack data on the southern hemisphere. We roughly agree with the work of Krasnopolsky [2007. Long-term spectroscopic observations of Mars using IRTF/CSHELL: mapping of O2 dayglow, CO and search for CH4. Icarus 190, 93-102] for LS=331-360°, thus confirming the effect of seasonal condensation of CO2 on the north polar cap, but we have no agreement for other seasons.  相似文献   
4.
陆梦秋  陈娱 《地理科学》2019,39(9):1416-1424
在“一带一路”倡议背景下,探讨中欧集装箱运输通道的空间格局对中欧班列运输组织优化及欧亚大陆一体化发展具有重要意义。基于铁路货运网络数据提取了各地市节点的对欧运输最短路径,采用集装箱货源系数算法对各地市对欧进出口总额进行加权计算,用以表征腹地对欧陆运集装箱生成量,模拟潜在的中欧集装箱铁路运输流汇集格局。研究表明:在满洲里、二连浩特和阿拉山口三大陆运优势片区分别形成了沿大连-营口-锦州-通辽-白城-齐齐哈尔-满洲里集装箱运输东通道,沿上海-南京-济南-天津-北京-乌兰察布-二连浩特集装箱运输中通道,以及沿杭州-合肥-西安-兰州-乌鲁木齐-阿拉山口集装箱运输西通道;长三角地区是中、西通道的始流区域,区域内城市通过两通道运输集装箱的成本相当;集装箱流量汇集的关键节点共22个,其中,齐齐哈尔、乌兰察布、北京、济南、南京、乌鲁木齐和西安为第一等级汇集点。  相似文献   
5.
Facilities connectivity is a priority area for implementing the Belt and Road Initiative (BRI). The “China-Europe Railway Express” (CER Express) mode of transport organization links China with Europe by fast-track cargo rail. A major instance of facilities connectivity related to this project is an important practical and symbolic instance of BRI transport cooperation. The strategic significance of the CER Express and a number of operational issues are outlined, as are the implications of limited market potential for costs and competitiveness. A “hub-and-spoke” organizational model that can generate scale economies and reduce costs is proposed. To examine the establishment of an organizational model of this kind, the economic hinterlands of Alashankou, Erenhot, and Manzhouli are identified under high-, mediumand low-cost scenarios using an analytical methodology that determines distance and economic costs, and a number of transport hubs (that include Harbin, Zhengzhou, and Lanzhou) are identified. The results found that the cost of the routes from 314 Chinese cities to Moscow is the lowest via Manzhouli in the high- and medium-cost scenarios, but the routes change via Erenhot in the low-cost scenario. A number of policy recommendations should follow up.  相似文献   
6.
In this study, magnetic field measurements obtained by the Venus Express spacecraft are used to determine the bow shock position at solar minimum. The best fit of bow shock location from solar zenith angle 20-120° gives a terminator bow shock location of 2.14 RV (1 RV=6052 km) which is 1600 km closer to Venus than the 2.40 RV determined during solar maximum conditions, a clear indication of the solar cycle variation of the Venus bow shock location. The best fit to the subsolar bow shock is 1.32 RV, with the bow shock completely detached. Finally, a global bow shock model at solar minimum is constructed based on our best-fit empirical bow shock in the sunlit hemisphere and an asymptotic limit of the distant bow shock which is a Mach cone under typical Mach number of 5.5 at solar minimum. We also describe our approach to making the measurements and processing the data in a challenging magnetic cleanliness environment. An initial evaluation of the accuracy of measurements shows that the data are of a quality comparable to magnetic field measurements made onboard magnetically clean spacecraft.  相似文献   
7.
京沪高铁轨道板精调相关技术问题研究及对策   总被引:1,自引:0,他引:1  
介绍了轨道板博格精调技术,详细论述并有效改进了精调操作流程,针对精调过程中常见问题提出了解决办法,最后对轨道板的精调成果进行了简要分析。  相似文献   
8.
We present radiative transfer modelling of thermal emission from the nightside of Venus in two ‘spectral window’ regions at 1.51 and 1.55 μm. The first discovery of these windows, reported by Erard et al. [Erard, S., Drossart, P., Piccioni, G., 2009. J. Geophys. Res. Planets 114, doi:10.1029/2008JE003116. E00B27], was achieved using a principal component analysis of data from the VIRTIS instrument on Venus Express. These windows are spectrally narrow, with a full-width at half-maximum of ∼20 nm, and less bright than the well-known 1.7 and 2.3 μm spectral windows by two orders of magnitude.In this note we present the first radiative transfer analysis of these windows. We conclude that the radiation in these windows originates at an altitude of 20-35 km. As is the case for the other infrared window regions, the brightness of the windows is affected primarily by the optical depth of the overlying clouds; in addition, the 1.51 μm radiance shows a very weak sensitivity to water vapour abundance.  相似文献   
9.
Hydroxyl nightglow is intensively studied in the Earth atmosphere, due to its coupling to the ozone cycle. Recently, it was detected for the first time also in the Venus atmosphere, thanks to the VIRTIS-Venus Express observations. The main Δν=1, 2 emissions in the infrared spectral range, centred, respectively, at 2.81 and 1.46 μm (which correspond to the (1-0) and (2-0) transitions, respectively), were observed in limb geometry (Piccioni et al., 2008) with a mean emission rate of 880±90 and 100±40 kR (1R=106 photon cm−2 s−1 (4πster)−1), respectively, integrated along the line of sight. In this investigation, the Bates-Nicolet chemical reaction is reported to be the most probable mechanism for OH production on Venus, as in the case of Earth, but HO2 and O may still be not negligible as mechanism of production for OH, differently than Earth. The nightglow emission from OH provides a method to quantify O3, HO2, H and O, and to infer the mechanism of transport of the key species involved in the production. Very recently, an ozone layer was detected in the upper atmosphere of Venus by the SPICAV (Spectroscopy for Investigation of Characteristics of the Atmosphere of Venus) instrument onboard Venus Express (Montmessin et al., 2009); this discovery enhances the importance of ozone to the OH production in the upper atmosphere of Venus through the Bates-Nicolet mechanism. On Venus, OH airglow is observed only in the night side and no evidence has been found whether a similar emission exists also in the day side. On Mars it is expected to exist both on the day and night sides of the planet, because of the presence of ozone, though OH airglow has not yet been detected.In this paper, we review and compare the OH nightglow on Venus and Earth. The case of Mars is also briefly discussed for the sake of completeness. Similarities from a chemical and a dynamical point of view are listed, though visible OH emissions on Earth and IR OH emissions on Venus are compared.  相似文献   
10.
A measured calibrated solar radiance in the range 1.2-, with the spectral sampling of does not exist. When studying the measured Planetary Fourier Spectrometer (PFS) spectra of the Earth's or Mars's atmosphere we discover that the most used solar spectrum contains several important errors. Here we present a “calibrated” solar radiance in the wavelength range 1.2-, with the spectral resolution of PFS , which we are going to use for studying Martian spectra. This spectrum has been assembled using measurements from Kitt Peak and from ATMOS Spacelab experiment (uncalibrated high resolution) and theoretical results, together with low resolution calibrated continuum. This is the best we can have in this moment to be used with PFS, while waiting to have good solar calibrated radiances. Examples of solar lines at Mars are given.  相似文献   
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