The Belt and Road Initiative (BRI) has changed from a China-based initiative to an international consensus, and is becoming a platform for a growing number of countries in the world to explore new international economic governance mechanisms. Such a great change along with impressive achievements of BRI development has attracted academic attention from almost all disciplines except basic sciences, giving rise to huge literature. This paper will first explore data from China Knowledge Resource Integrated Database to summarize the characteristics of literature on BRI in general, and then review progress in research on major BRI topics related to geography. The paper finds: (1) the number of Chinese papers on BRI increased by 21 times in three years, from 1012 in 2014 to 21216 in 2017; (2) these papers cover various BRI-related topics but most of them are macroscopic and very general studies of BRI with a taste of public voices, implying that quality papers with deep academic studies are demanded to support the BRI development; (3) more frequently discussed topics are China's outward foreign direct investment, facilities connection, "going out", globalization, global economic governance, community of shared destiny and internationalization of Renminbi; and (4) specific topics that are more deeply studied by geographers are connotation and discourse of BRI, geopolitical analysis of BRI, China-Europe Express Train, global strategic shipping pivot, model of China's outward foreign direct investment and overseas industrial parks, trade pattern and its impacts on economic growth of both China and its trade partners. Lastly, the paper suggests enhancing the discursive construction of BRI and studies of new BRI mechanisms as well as studies of countries involved in BRI, and promoting dialogues and collaborations between Chinese scholars and foreign scholars on BRI studies.

“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。

The Belt and Road Initiative—where the "Belt" stands for the Silk Road Economic Belt and the "Road" stands for the 21st Century Maritime Silk Road—is a call of China for new modes of regional economic cooperation under the trend of development of economic globalization. It targets at promoting orderly and free flow of economic factors, efficient allocation of resources, and deep integration of markets; enabling the countries along the Belt and Road to achieve economic policy coordination and carry out broader, deeper, and more efficient economic cooperation; and jointly building an open, inclusive, and balanced regional economic cooperation architecture. Thus the Belt and Road Initiative is an alternative road to further economic globalization, but contains ideas that are different from the past, that is, the spirit of the Silk Road—"peace and cooperation, openness and inclusiveness, mutual learning and win-win." Based on such an understanding, this article first analyzes the general background of the Belt and Road Initiative against economic globalization and the changing configurations of the world, and then discusses the Initiative's spatial connotation by revealing its multi-scalar and trans-scalar characteristics. The article points out that the Belt and Road Initiative is a national strategy, rather than a regional strategy, to coordinate all-around opening of China to the world and promote further integration of the country into the global economy. Last, the article suggests several research themes in geography that are brought about by the Belt and Road Initiative, including geopolitical studies, geography of countries of the region to explore cooperation opportunities, foreign direct investment theories advanced by the Belt and Road Initiative, and optimization of transcontinental transportation.

“一带一路”指“丝绸之路经济带”和“21世纪海上丝绸之路”,是中国为推动经济全球化深入发展而提出的国际区域经济合作新模式。其核心目标是促进经济要素有序自由流动、资源高效配置和市场深度融合,推动开展更大范围、更高水平、更深层次的区域合作,共同打造开放、包容、均衡、普惠的区域经济合作架构。“一带一路”框架包含了与以往经济全球化完全不同的理念,即“和平合作、开放包容、互学互鉴、互利共赢”,这正是丝绸之路文化内涵的体现。本文分析了“一带一路”战略与经济全球化及世界格局变化的关系;剖析了其空间内涵,认为“一带一路”具有多重空间内涵和跨尺度特征,是统筹中国全面对外开放的国家战略。最后,提出了推进“一带一路”建设为地理学提出的几个重要议题,包括地缘政治、国别地理、对外直接外资理论、交通运输优化组织等。

Since the proposition of “Belt and Road Initiative”, researches on trade between China and countries along the Initiative area have increased. However, it is relatively rare to study trade network taking China and those countries as a whole. In this article, we utilize a social network analysis method to analyze the characteristics, trade groups as well as core-periphery structure and its evolution of this trade network. Then we analyze the structure of sub trade network of China and the Southeast Asian countries. The results show that density of the trade network established by China and countries along “Belt and Road Initiative” areas has increased, coupled with growing number of core countries. Meanwhile, China’s core degree in this trade network has increased with China being the most important core country in 2013. What’s more, China becomes the core country in the sub trade network of China and the Southeast Asian countries as well. Based on this analysis, we propose that during the process of promoting “Belt and Road Initiative” construction, China should rely on policy communication to reduce trade barriers and improve trade facilitation with countries along the Initiative area. In particular, it should be set as the priority to facilitate trading conditions with core countries in the Initiative area trade network for further enhancing China’s core position in this network. What’s more, China should make good use of the advantage of being the core position in the network, play an active role of being the area core country and promote the construction and development of “Belt and Road Initiative”.

采用社会网络的分析方法分析了“一带一路”沿线国家贸易网络的基本特征以及贸易网络组团的结构变化,贸易网络的核心边缘及其演化情况,并在最后对中国与东南亚国家的子贸易网络进行了核心边缘分析。结果表明：“一带一路”沿线国家贸易网络密度增强,中国在“一带一路”沿线国家贸易网络中的核心度在逐渐提高,在2013年已经成为最核心的国家,且在中国与东南亚国家构成的子贸易网络中,中国也成为了最核心的国家。

Economic cooperation is one of the priority areas in the "Belt and Road Initiative" proposed by China. It is important to examine the characteristics and patterns of development of trade between China and countries in the "Belt and Road Initiative" area, for achieving "unimpeded trade" and promoting economic prosperity and regional cooperation. Under this background, this article reviews the changing trend of commodity structure of trade between China and countries in the "Belt and Road Initiative" area, and analyzes the commodity structure and pattern, based on the revealed comparative advantage index (RCA), sensitive industry identification method, and k-medium value clustering. The results show that the commodity structure of China's export to these countries has improved, while import has been more centralized with increasing share of energy. Second, the main products that China exports to these countries are mechanical equipment and textiles and garments, while the main products that China imports are mostly energy, textiles and garments, and mechanical equipment. Third, sensitive industries involved in China's exports include clothing and shoes, nonmetallic minerals, transportation equipment and so on, and those involved in China's imports are mainly ores, energy, and some primary processed products. Fourth, at the provincial level, eastern, central, and some western provinces that do not share border with other countries, are mainly connected to Southeast Asia, West Asia, and Middle East, while western and northern border provinces are mainly dependent on trade with neighboring countries in the area, and have more ties with Central Asia, South Asia, and Mongolia-Russia. Most eastern provinces, central provinces, and several fast-growing western provinces are mainly exporting mechanical equipment, while most northwestern provinces are mainly exporting clothing. On the other hand, energy is the main product imported to Qinghai, Xinjiang, Liaoning, Heilongjiang, and other eastern provinces, while ores and metal products are main imported to most western provinces.

经贸合作是“一带一路”建设的重点内容之一。研究中国与“一带一路”沿线国家的经贸合作演变特点及格局,对于促进沿线各国经济繁荣与区域经济合作,实现“贸易畅通”具有重要意义。本文在文献回顾的基础上,基于大量的数据分析,梳理了2001年以来中国与沿线国家贸易的商品结构演化历程,并采用显性比较优势指数、敏感性行业度量及k值聚类算法等,对中国与沿线国家贸易商品结构及格局进行了深入分析。研究结果显示：①中国对沿线国家的出口商品结构有所优化,进口商品结构日趋集中,能源及劳动密集型产品比重上升;②中国与沿线国家贸易的商品结构与各国出口优势行业基本一致;③中国与经济规模相对较小且产业结构较为单一的国家存在一些敏感性行业,出口方面涉及服装鞋帽、矿物制品及交通运输设备等,进口主要涉及能源、矿砂及一些资源初级加工品;④由于国内各省发展差距明显,中国出口商品的空间连续性较差。

This study explores the trade pattern and influencing factors between China and countries along “ the Belt and Road” route using the gravity model of trade. With the implementation of China’s “the Belt and Road” initiative, the growing trade between China and countries along “the Belt and Road” route gradually became the principal measured standard of the achievements of the “the Belt and Road” initiative and an essential sign of implementing the concept of “the Belt and Road” initiative. Based on the five types of connectivity of “the Belt and Road” initiative, including connectivity of policy, infrastructure, trade, finance, and people, we unravel the factors influencing the trade between China and countries along “the Belt and Road” route and conduct a quantitative analysis of the factors. This study found that the total trade volume in the total import and export between China and countries along “the Belt and Road” route is influenced by the level of economic development, the size of each country’s market, the political system, accessibility and convenience of trade, and China’s foreign direct investment and non-governmental exchange and cooperation. Among these, China’s foreign direct investment shows hysteresis in promoting trade development between China and countries along “the Belt and Road” route. Because of each country’s different economic policies, trade policies, and international relations, the delay period between China’s foreign direct investment and trade development could differ. China’s foreign direct investment in countries along “the Belt and Road” route, however, has the most positive effect two years after the investment flowing into the host country. This study also found that China’s foreign direct investment has various effects on the total trade volume in the total import and export between China and countries along “the Belt and Road” route. They can be divided into four types: strong driving, driving, general, and insufficient driving. The countries in the strong driving type and driving type are in Southeast Asia, western Asia, and sub-Saharan Africa. This study enriches the domestic empirical research on the influencing factors of foreign trade between China and countries along “the Belt and Road” route, helps to improve the efficiency of Chinese enterprises’ overseas investment, and contributes to promoting the communication on economics and trade between China and countries along “the Belt and Road” route. This study also puts forward the view that China’s foreign direct investment shows hysteresis in promoting trade development. Future research could focus on the differences of the delay period in different industries between China’s foreign direct investment and the economic and trade development in the host country, exploring ways to shorten the delay period from the policy perspective and better promote the implementation of “the Belt and Road” initiative.

利用拓展贸易引力模型,借助Eviews等工具分析了影响中国与“一带一路”沿线国家贸易规模的因素,以及中国对外直接投资的滞后性对双边贸易的影响。结果表明：1）中国与“一带一路”沿线国家贸易规模受到经济发展水平、市场规模、政治制度、贸易畅通性、便利性、中国对外直接投资、民间文化交流紧密度的影响;2）中国对外直接投资对于带动中国与“一带一路”沿线国家间的贸易规模具有正向作用,但其效应具有一定滞后性;3）中国对外直接投资对于带动中国与不同“一带一路”沿线国家贸易规模的引力大小不同,可分为投资带动力巨大型、投资带动型、投资一般型、投资带动力不足型4种类型,中国与东南亚、西亚和撒哈拉以南的非洲国家贸易规模受中国对外直接投资带动作用较强。

The paper, from the perspective of social network, explores the spatial patterns and evolutionary characteristics of the global trade network and focuses on the Chinese community ownership and their strategic implications by adopting social network indexes, including centrality, community classification and structure entropy. The results show that: (1) The structure of global trade network evolved towards complexity, specifically shifted from "one super state and more powerful countries" towards"multi-polarization". The collective rise of developing countries has weakened the monopoly position of traditional European and American countries in the network, leading to increasing complexity of the network structure. (2) Community evolution of the global trade network has experienced the dominant stage of the developed countries, the budding stage of the Asian region, the separated stage of the Asian Community and the fourth stages of "ripartite confrontation". During the evolution, China has gradually moved from being dominated to the center of the stage. (3) The diversification of trade market is a common characteristic of foreign trade countries. In the process of global market segmentation, China, the United States, and Germany gradually formed a relationship of "dislocation competition", and their core interests are concentrated around the surrounding areas. (4) The areas of Asia-Pacific Region, Middle East, Africa and Latin America have become the play field of China to compete other powers for local trade markets. Currently, the Asia-Pacific market is the preferred market for China's global trade, and China should extend the market to the Middle East, Africa and Latin America through "Silk Road Economic Belt and 21st Century Maritime Silk Road", In this way, economic advantage can be transformed into global strategic influence. Meanwhile, direct conflicts and confrontations with the core interests of the United States should be avoided.

从社会网络视角,采用中心度、社团划分和结构熵等社会网络指标,探究全球贸易网络的空间格局及演化特征,重点分析中国在网络中的社团归属及其地缘战略启示。研究表明：随着时间推移,发展中国家的群体性崛起使得全球贸易网络结构呈现日益多元化的复杂格局;全球贸易网络的社团演化经历了发达国家主导、亚洲崛起的萌芽、亚洲社团的分离和“三足鼎立”四个阶段,中国从被支配的边缘地位逐步走向“舞台中央”;中、美、德三国在全球市场细分过程中形成一种“错位竞争”关系,亚太、中东、非洲和拉美地区成为大国之间争夺贸易市场的博弈区域。中国应首先立足于亚太地区,通过“一带一路”倡议延伸至中东、非洲和拉美地区,将经济优势转化为全球战略影响力。

Trade network research originated from complex network science, and its study is related to the globalization research of economic geography. However, relational economic geography, engaging in globalization research and social network and network science, has hardly participated in trade network research. In response to this phenomenon, this article critically reviewed the origin, process, and achievements of the network paradigm of relational economic geography and examined the progress of trade network research, to rethink how relational economic geography should participate in the discussion of trade networks. This article presented the following findings: 1) The network paradigm of relational economic geography only borrows a small part of the concepts of social network analysis, and pays little attention to the overall structure of the network and its influence on collective behaviors. 2) Trade network research mainly discusses the structure and nature of trade networks through building topological network between countries, but relational economic geography based on the actor perspective (for example, enterprises and local agent) is difficult to use social network analysis methods. 3) Relational economic geography should attach importance to global cluster network, and rethink the economic geography foundation of the network concept and the research on the mutual coupling relationship of multi-dimensional networks. This article has implications for expanding the research fields of relational economic geography and for exploring the application of theories and new methods of economic geography.

贸易网络研究起源于复杂网络科学,其研究问题属于经济地理学全球化关注范畴。然而,关系经济地理作为经济地理全球化研究的中坚力量,同样借鉴社会网络和网络科学的思想,几乎没有参与到贸易网络的研究和对话中。论文针对这一现象,从介绍关系经济地理的网络范式入手,阐述关系经济的网络范式来源、过程与研究成果,并梳理现有贸易网络研究的进展,分析现阶段关系经济地理的网络思潮与贸易网络的区别,重新思考经济地理在关系视角下,应该以何种方式参与到贸易网络的讨论中。主要结论如下：① 关系经济地理的网络范式仅仅借用社会网络研究小部分概念,重视在整体网络空间中行动者的嵌入性,几乎不关注网络的整体结构及其对集体行为的影响;② 贸易网络研究主要探讨国家间贸易网络的结构与性质,而关系经济地理普遍从企业出发研究贸易流动背后的生产网络,其理论基础难以使用社会网络分析方法;③ 关系经济地理的贸易网络研究应该重视全球集群网络理论的运用,重新思考网络概念的经济地理学基础和多维网络相互耦合关系研究等问题。论文有助于推动关系经济地理学学者如何借助学科理论基础参与到贸易网络国际化研究中,对探讨现阶段经济地理理论应用和新方法实践具有重要的积极作用。

In the era of economic globalization, with the frequent commodity flows between countries and prominent characteristics of commodity trade networking, it is urgent to explore the interactions and evolution mechanism of global commodity trade based on the logic of the relationship network. Combining the social network analysis method and ArcGIS visualization tool and based on the data of commodity trade flow in various countries from 1996 to 2016, this study revealed the growth process, spatial patterns, and dynamic mechanism of the global commodity trade network. The results indicate that: (1) The network shows expansionary growth, and the “big triangle” of spatial structure with the interaction of three cores is becoming increasingly more mature. The advantages of the three commodity trade clusters also become clearer. The cluster led by China has expanded dramatically, while those led by the United States and Germany have shrunk. Division of labor in the network is clear among countries, and the network functions are significantly different and show different characteristics of change. (2) The growth of global commodity trade networks is driven by endogenous dynamics such as self-organization, national matching, national distribution, as well as external thrusts such as exogenous network embedding. Reciprocal relationships are the main structure of self-organization. National income levels, market opening convergence, and institutional environment heterogeneity are the key factors of matching. Economic advantages and industrial competitiveness are important foundations of distribution. The colonial history network, the international student exchange network, the language isomorphism network, and the cooperative publication network are important exogenous networks. The law of comparative advantage is still applicable to explain the growth of global commodity trade networks, especially for national matching and distribution.

经济全球化时代,国家间商品流动频繁,商品贸易网络化特征突出,亟需从关系网络的生长逻辑探究全球商品贸易的互动场景与演进机理。本文基于1996—2016年全球商品贸易流量数据,借助社会网络分析方法和ArcGIS可视化工具揭示了全球商品贸易网络的生长过程,运用指数随机图模型分析了全球商品贸易网络生长的动力机制。结果表明：①全球商品贸易网络呈扩张式生长,逐步形成“三核”互联主导的“大三角”空间结构,网络骨架的三大集群凸显。中国主导的集群大幅拓展,美国和德国主导的集群日益收缩。各国家（地区）在网络中的分工明确,网络功能差异显著并表现出不同变化特征。②全球商品贸易网络生长受自组织性、国家（地区）匹配性、国家（地区）集散性等内生动力和外生网络嵌入性等外在推力的共同驱动。其中,互惠关系是自组织性的主要结构,国家（地区）收入水平、市场开放趋同性和制度环境异质性是匹配性的关键因素,经济优势和产业竞争力是集散性的重要基础,殖民历史网络、留学生交流网络、语言同构网络、论文合作网络是重要的外生网络。传统的比较优势理论仍然适用于全球商品贸易网络生长机理的解释,尤其对国家（地区）匹配性和集散性的解释力更强。

With the development of the network analysis methods, studying global trade network by community detection and social network analysis (SNA) has become the frontiers in trade-related fields. However, most of the present research was of short temporal scale. Long-term studies are needed particularly given the growing uncertainties in today's world economy. Under the implementation of the Belt and Road initiative, analyzing the dynamics of the world politics and economy after the 1980s as well as the long-term shifts of the role of countries are of great significance for revealing the evolution of global trade network and thus contributing to the improvement of the initiative. Based on the Direction of Trade Statistics (DOTS) database by the International Monetary Fund (IMF), this article summarized three main stages in the global trade history after 1980 and illustrated and analyzed the change of the global trade network. The study found that: 1) The changes of world politics and economy and the improvement of technologies greatly influenced the global trade. The transformation from Fordism to Post-Fordism, the extension of neoliberalism, the development of digital technology, and the rise of developing countries represented by China have profoundly reshaped global trade. 2) The Top 1 network indicates that the change of global trade is relatively stable despite some shifts. In the European part of the global trade network, German bloc, French bloc, and Russian bloc are somewhat steady, while the United Kingdom bloc and Italian bloc have declined. In the Asia-Pacific part, the United States always played the leading role, the Australian bloc remained unchanged, but the Japanese bloc experienced a recession. 3) The rise of developing countries, such as India, Brazil, and South Africa, led to the great transformation of the world economy and trade network. These countries have recently become the regional trading centers. 4) With a high-speed development of the economy, China saw a dramatic rise in global trade and has become the center of the largest global trade bloc, exceeding the United States. Finally, this article briefly discussed the importance of long-term trade network research for the Belt and Road initiative.

随着网络分析方法的发展,利用社团检测和社交网络分析研究世界贸易网络成为当前重要的前沿问题。但目前国内外的研究多为短期尺度,中长期尺度研究亟需更新。当前世界经济发展不确定性要素增多,“一带一路”建设正进入深耕细作的阶段,分析20世纪80年代以来国际政治经济局势的转变以及发达国家与发展中国家的地位更替的长尺度变化,有利于揭示世界贸易网络的中长期演变趋势,并为中国“一带一路”建设提供历史启示。论文主要基于国际货币基金组织(IMF)的贸易方向统计数据库(DOTS),首先总结了1980—2018年世界贸易发展3大历史阶段的基本特征,然后研究了20世纪80年代以来的世界贸易网络中组团及国家地位的演变。研究发现：① 世界政治经济格局变化和技术进步对世界贸易网络影响深远。20世纪80年代以来资本主义的生产方式由福特制向后福特制的转变、新自由主义的推广、数字技术的大规模发展以及发展中国家的崛起对全球贸易空间格局产生了深远的影响,中国的崛起是全球贸易网络变化重要的力量。② 从Top1贸易网络上看,世界贸易格局呈现出“稳中有变”的演化趋势。世界贸易网络中,欧洲部分的德国、法国和俄罗斯组团相对稳定,而英国和意大利组团地位不断下降;美国主导了亚太部分,澳大利亚组团较为稳定,日本组团地位下降。③ 印度、巴西和南非等发展中国家的崛起,导致世界经济和贸易格局的重大变化,这些国家近年来成为了新兴的区域性贸易中心。④ 随着经济高速发展,中国在世界贸易中的地位迅速上升,成为了超过美国的世界贸易组团核心。最后,简要讨论了中长期尺度贸易网络研究对“一带一路”建设的历史启示。

Since 2018, with the major adjustment of the global political and economic structure, Sino-US relations, which take trade friction as the representation and science and technology competition as the essence, have become increasingly tense. Based on this, this paper characterizes the evolution of global high-tech products trade structure from three aspects of product structure, network structure and influencing factors, and draws some conclusions. First of all, in terms of product structure, global high-tech trade is increasingly concentrated on electronic communication products based on telecommunications equipment. However, on the national scale, chemical products and armament products are not only the dependence products of most countries (regions) on imports, but also the superior export products of most countries (regions). Second, in terms of topology, the global high-tech product trade network continues to expand and is closely linked. It is a typical small-world network and develops a stable "core-edge" hierarchical structure. Third, in terms of spatial structure, the global trade pattern of high-tech products has changed from Europe-North America dominated to East Asia dominated, and also the largest trade country has changed from the United States to China. In addition, the spatial structure has changed from the "double arch" structure with the United States as the core to the "multi-arch" pattern with China as the core, but the United States still occupies a central position in the trade network of various high-tech products. Fourth, in terms of influencing factors, trade scale, economic proximity and cultural proximity have positive effects on the evolution of global high-tech products trade network, while geographical distance has an obvious negative effect. The four factors of political stability, openness, infrastructure and technological innovation only pass the significance test on the importing country (region), while the economic scale only passes the significance test on the exporting country (region). The technological gap is one of the driving forces for the evolution of the global high-tech product trade network.

为清晰刻画全球高科技产品贸易体系变迁,本文利用世界银行以及联合国商品贸易数据库中2000—2017年高科技产品贸易数据,从产品结构、网络结构和影响因素3个方面探讨了全球高科技产品贸易结构的演化态势。研究发现：① 产品结构上,以电信设备为主的电子通讯产品主导全球高科技贸易发展,但在国家尺度上,化学产品和武器产品是大部分国家（地区）的进口依赖产品或出口优势产品;② 拓扑结构上,全球高科技产品贸易网络持续扩张,联系紧密,是一典型的“小世界”网络,并发育出稳定的“核心—边缘”式的等级层次结构;③ 空间结构上,全球高科技产品贸易格局呈现出由欧洲—北美主导向由东亚主导转变,贸易最大国也由美国转变为中国,网络空间结构也呈现出由以美国为核心的“双拱”格局向以中国为核心的“多拱”格局转变,但美国依然在多种高科技产品贸易网络中占据核心地位;④ 影响因素上,贸易规模、经济邻近性和文化邻近性对全球高科技产品贸易网络演化皆具有一定的正向作用,地理距离对全球高科技产品贸易网络的演化起到明显的负向作用。

<p>Trade facilitation is one of the five main agendas of the Belt and Road Initiative (BRI). Social network analysis has helped understand the complexity of trade networks, but existing studies tend to overlook the fact that not all bilateral trade relations are equally important to a country. To fill this gap in the literature, this paper focuses on the top 2 trade relations networks to illuminate the structure and evolution of B&R trade relations, the relative positions of different countries, and changes in the composition of trade communities (e.g., the community leaders) and the changing patterns of trade between them. We find rich dynamics over time both inter- and intra-communities. The overall international trade networks of B&R countries experienced a leadership change from Russia to China on one hand, some temporary communities experienced emergence, disappearance (e.g. the Kuwait- and Thailand-led communities) or reemergence (e.g. Poland-led community), and a community membership was generally consistent on the other hand. Since the future impacts of China’s BRI will depend on the degree of integration of the connected regions, some countries with stable and high centrality indices (e.g. Russia, Singapore, Serbia, Greece, Turkey, Iran, Poland, Hungary and Romania) could be selected by China as strategic regional partners, and countries with a strategically important geographical position but weak trade links (e.g. Myanmar, Pakistan, and Belarus) should be prioritized.</p>

Unimpeded trade is one of the priorities of cooperation in the Belt and Road Initiative proposed by China. On 15 May 2017, the Joint Communique of the Leaders Roundtable of the Belt and Road Forum for International Cooperation reaffirmed the participants' shared commitment to build an open economy and ensure free and inclusive trade. The Belt and Road Initiative (BRI) is not only China's new action to drive its open and global development, but also a platform for increasingly more countries to explore free and inclusive trade. It is therefore important to examine the topological relationship between BRI trade network and global trade network, for promoting a universal, rule-based, open, nondiscriminatory, and equitable multilateral trading system. Based on a literature review, this article first analyzes community structure and trade network based on community detection algorithm, and then estimates the topological relationship of different trade communities. The findings of this article are as follows. First, we identified five trade communities in global trade network through community detection algorithm, in which China, USA, Russia, India-UAE, and Germany-the Netherlands-France-Britain and other European developed countries are the cores of the five trade communities, respectively. Second, we identified three trade communities and two sub-communities in the BRI trade network, in which China is the core, Russia is the sub-core of the biggest trade community, and India, UAE, and Saudi Arabia are cores of the second trade community (South Asia-West Asia). Third, the topological analysis results indicate that in the global trade network, most BRI countries are attracted by the core nodes in the BRI area, such as China, Russia, India-UAE core nodes, and have strong trade contact with BRI countries. Most Central-East European countries are mainly attracted by Germany-the Netherlands-France-Britain and other European developed countries with low penetration of BRI trade. Although some Southeast Asian countries are incorporated into the Asia-Australia-South Africa community with China as the core, they still need to strengthen trade linkages with BRI countries.

共建“一带一路”倡议致力于建设开放型经济、确保自由包容性贸易。本文基于社区发现法、拓扑网络可视化等方法,对比分析“一带一路”贸易网络与全球贸易网络的拓扑关系,明确其贸易在全球的地位,以期为“一带一路”自由包容性贸易体系建设提供科学支撑。研究发现：①全球贸易网络可以识别出5个组团,其核心节点分别是中国、美国、德—荷—法—英等欧洲发达国家、俄罗斯、印度—阿联酋。②“一带一路”沿线可以识别出3个主组团及2个次组团,其中,亚欧大组团以中国为核心、俄罗斯为次核心,南亚—西亚组团以印度、阿联酋、沙特阿拉伯为核心。③在全球贸易网络中,大部分沿线国家仍被中国、俄罗斯、印度—阿联酋等核心节点所吸引,且与“一带一路”沿线的贸易联系较强;中东欧国家主要被德—荷—法—英等西欧国家核心节点所吸引,是“一带一路”低渗透国家;部分东南亚国家虽然被吸纳到以中国为核心的亚澳—南非组团,但与“一带一路”贸易联系还需加强。

Unimpeded trade is one of the cooperation priorities in the Belt and Road Initiative proposed by China. On 15 May 2017, the Joint Communique of the Leaders Roundtable of the Belt and Road Forum for International Cooperation reaffirmed the participants’ shared commitment to build an open economy and ensure free and inclusive trade. The Belt and Road Initiative (BRI) is not only China's new action to drive its open and global development, but also a platform for an increasing number of countries to explore free and inclusive trade and promote a universal, rule-based, open, non-discriminatory, and equitable multilateral trade system. It is therefore important to examine the topological relationship between the BRI and global trade networks. More specifically, this article first analyzes the community structure of trade networks using a community detection algorithm, and then estimates the topological relationship between different trade communities. The findings of this article are as follows. First, this research identified three trade communities and two sub-communities in the BRI trade network, in which China is the core, Russia is the sub-core of the biggest trade community, and India, United Arab Emirates, and Saudi Arabia are cores of the second trade community (South Asia-West Asia). Second, it identified five trade communities in the global trade network, centred on China, USA, Russia, India-United Arab Emirates, and Germany-Netherlands-France-Britain and other European developed countries. Third, the topological analysis indicated that in the global trade network, most BRI countries are attracted by the core nodes of the BRI regions, such as the China, Russia and India-United Arab Emirates core nodes, and have strong trade contacts with BRI countries. Most Central-East European countries are mainly attracted by Germany-Netherlands-France-Britain and other developed European countries with a low penetration of BRI trade. Although some Southeast Asian countries are incorporated into the Asia-Australia-South Africa community with China as the core, they still need to strengthen trade linkages with BRI countries.

<p>The Belt and Road Initiative (B&R) is aimed at building a multi-faceted, multi-dimensional, and a compositely interconnected network. The B&R orderly accelerates the free flow of economic factors across the area and further increases the integrated efficiency of regional economic resources in the B&R region, which has significant influence on reshaping the political and economic landscape of Eurasia and optimizing the geopolitical environment around China. Based on the complex network theory and the geostatistical analysis, this research focuses on the topological features and the spatial structure of the B&R trade network and the proximity of its nodes, by building a database and applying the related techniques, such as ArcGIS, Pajek, and Stata. The main conclusions are as follows: (1) The trade network in the B&R region is a small world and scale-free network. It keeps growing and follows the optimum selection rules, which means the new nodes preferably connect with the existing nodes of higher degree in the network. (2) Countries in the B&R trade network display the typical core-periphery hierarchical character. China plays a leading role in promoting industrial upgrading and economic development for these countries. (3) The structure of the B&R trade network shows a "mixed" structure, including both the hub-spoke and the fully-connected modes. The spatial heterogeneity among different kinds of centralities is significant. (4) The extended gravity model can better explain the B&R trade network. There exist the "Powers' Effect" and the "Geographical Proximity Effect" in the trade relationship. In the B&R trade network, scientific and language proximity are the most important forces. Institutional proximity shows a significantly negative effect, while cultural proximity shows a relatively weak effect. As a result, China should develop diverse policies that are based on different spatial levels, enhance the trade with the neighbouring countries first, and then to the distant ones and their surrounding areas; leverage the advantage of scientific and language proximity to promote the trade with other countries, and strengthen the cultural infiltration along the B&R region.</p>

“一带一路”倡议致力于构建全方位、多层次、复合型的互联互通网络,沿线国家之间相互贸易形成的网络有利于加速经济要素跨区域的自由流动,进一步提升“一带一路”区域经济资源的整合效率,对重塑欧亚大陆政经版图和优化中国地缘环境具有重大影响。采用复杂网络和地统计方法,借助GIS、Pajek、Ucinet和数据库等技术手段,对“一带一路”贸易网络的拓扑性质、空间结构以及节点的邻近性深入研究。主要结论有：① “一带一路”沿线国家贸易网络具有小世界和无标度性质,遵循增长性和择优选择;② 沿线国家贸易具有典型的“核心—边缘”等级性,中国对沿线国家产业升级和经济发展具有引领和带动作用;③ 贸易网络是“混合型”结构,呈现枢纽辐射式为主、全连通式并存的联系模式,不同中心性空间分布差异显著;④ 拓展引力模型对“一带一路”沿线国家贸易网络具有较强的解释力,贸易关系存在大国效应和地理邻近效应,科研邻近和语言邻近是重要的推动力,制度邻近的影响呈显著负相关,文化邻近的正向作用相对较弱。因此,中国宜遵循“由近及远”的原则,重点强化对邻近国家的贸易渗透,再加强对沿线重点国家的贸易辐射,进而向重点国家的周边地区拓展,从不同空间层次制定差异化政策,发挥科研和语言邻近的推动作用,强化对沿线国家的文化渗透。

Cereal trade is essential for economic and commercial cooperation among countries along the “Belt and Road” (BRI). It helps ensure food security and contributes to building a community of interests and destinies for the BRI countries. Based on the UN Comtrade database, this study, using a network analysis approach, investigates the structural characteristics and spatiotemporal dynamics of cereal trade networks among the “Belt and Road” countries. Results show that: (1) The cereal trade among the BRI countries has formed well-connected and complex trade networks, and the “Belt and Road” initiative has significantly promoted cereal trade networks among the BRI countries. (2) The backbone structures of cereal trade networks along the BRI are in geographical proximity. India, Russia, and Ukraine are the most important trading partners and absolute core nodes in the trade networks, influencing the entire cereal trade networks. (3) The BRI cereal trade networks exhibit significant core-periphery structures, with considerable power asymmetries between the countries reflecting food supply and demand differences. In general, the BRI cereal trade networks have developed from relatively diversified to polarized. Supply chains in the cereal trade network are dominated by a few large countries and are fragile, with weak resilience and low resistance to risk. Therefore, governments should continue to strengthen regional cooperation, optimize cereal trade network structure, enhance their reserve capacity, and build a stronger system to guarantee food security and prevent risk. All these measures will support the food security of the “Belt and Road” countries.

Trade of agricultural commodities is an important part of the economic and trade cooperation between the Belt and Road countries, but the existing trade theories cannot fully explain the pattern and change of the cereal trade network between these countries. This study set up a four-dimensional analytical framework, combined social network analysis with spatial econometric analysis, and analyzed the spatial structure characteristics and mechanism of change of cereal trade network between the Belt and Road countries based on the United Nations Comtrade data from 1993 to 2016. The results show that: 1) The cereal trade network density of the Belt and Road countries is constantly increasing while the trade relations and trade intensity between these countries are constantly deepening. The position of the Belt and Road countries in the global grain trade network is on the rise and there is a clear phenomenon of trade club. 2) The network of trade relations has evolved from non-nuclear to multi-nuclear, and then to reshaping. 3) China's cereal trade with other Belt and Road countries has undergone an evolution from export-oriented to import-oriented. The Belt and Road initiative has enhanced China's position in the global grain trade network. 4) The evolution of the national cereal trade network of the Belt and Road countries is the product of resource endowment, economic environment, cultural identity, and political games. Compared with other trade networks, grain trade network has distinct characteristics and stronger stability. This study may provide some guidance for promoting cereal trade cooperation among the Belt and Road countries, optimizing trade structure, and ensuring food security.

农产品贸易是“一带一路”沿线国家间经贸合作的重要内容,但现有贸易理论无法很好地解释“一带一路”国家间粮食贸易网络的格局演化。该文构建了一个四维菱形分析框架,并将社会网络分析与空间计量分析相结合,基于1993—2016年联合国商品贸易数据,分析了“一带一路”国家间粮食贸易网络的空间结构特征及其演化机制。结果表明：① “一带一路”国家间的粮食贸易网络密度不断提高,贸易关系和贸易强度不断加深,在全球粮食贸易网络中的地位呈波动上升态势,并出现明显的贸易俱乐部现象;② 该粮食贸易网络呈现由无核到多核再到重塑的演化历程;③ 中国与其他“一带一路”国家间的粮食贸易经历了从出口导向到进口导向的演化历程,“一带一路”倡议提高了中国在全球粮食贸易网络中的地位;④ “一带一路”国家间粮食贸易网络的演化是受资源禀赋、经济环境、文化认同和政治博弈4个因素共同作用的结果,各因素在不同阶段所起的作用不同;粮食贸易较其他贸易而言特色鲜明,其稳定性更强。研究结果对促进“一带一路”国家农业贸易的健康繁荣,建设开放包容的经济环境具有指导意义。

Sustainable development is one common goal for the whole world, and regional cooperation is imperative to achieve that. Among the 17 sustainable development goals put forward by United Nations, the energy issue is one important part. It is necessary to better understand current energy consumption and trade pattern for energy consumption structure upgrade in the future. Hence, a study on petroleum trade along the "The Belt and Road Initiative" (BRI) can provide practical guidance for regional cooperation and sustainable development. This research uses social network analysis to investigate structural characteristics and evolution pattern with petroleum trade data of countries along BRI. We find that the primary structure of trade network keeps unchanged. Cohesion and core-periphery analysis results indicate that China has constructed a tight relationship with other countries and more trade links are sustained by fewer nations respectively, trade is still correlated to geopolitics. Regional trade network has resilience. Quadratic Assignment Procedure results show that the economic scale has a significant positive impact on trade in this region, neighboring countries tend to establish close trade relations, and the degree of policy communication and facility connectivity between countries needs to be further strengthened. Cultural interoperability also shows significant features, and related follow-up cooperation needs to be further deepened. (C) 2019 Elsevier Ltd.

From the perspective of economic geography, this paper studies the changing spatial pattern of world economy and China's role in different waves of economic globalization. Firstly, this study finds that the geographical pattern of world economy changes from "core-periphery" to "chain-reconfiguration", and to current "network-imbalance". Meanwhile the driving force of economic globalization shifts from "trade globalization" to "manufacturing globalization". At present, "multiple globalization" is involving into a new engine to driving the development of economic globalization. We then discuss that how China changes its role in economic globalization by changing modes of strategic coupling. We argue that the role transition of China breaks the traditional developing path which developed countries set for developing countries and theoretical spatial order put forward by classical industry gradient transfer, bringing new restructuring power and possibility for changing pattern of globalization. Finally, we discuss the impacts of COVID-19 pandemic on the development of economic globalization and the development trend of economic globalization in the post-pandemic era. Based on the analysis, we come up with some suggestions regarding to the potential development paths of China under the background of economic globalization.

经济全球化浪潮下的世界经济地理格局和中国角色演变一直以来都是学术界关注的热点问题,然而当前学界偏重从国家经济模式和国际贸易角度来解释这种格局的变化,而较为缺乏基于生产组织视角的经济地理解释。因此,本文从经济地理视角出发,解析经济全球化浪潮下世界经济地理格局变动与中国角色的演变。本文揭示了在三次全球化浪潮的冲击下,世界经济地理格局从&#x0201c;核心&#x02014;边缘&#x0201d;到&#x0201c;链式重构&#x0201d;再到&#x0201c;网络不均衡&#x0201d;的演变过程,以及经济全球化的驱动力如何从&#x0201c;贸易全球化&#x0201d;转变为&#x0201c;生产全球化&#x0201d;,继而朝&#x0201c;多元全球化&#x0201d;演进。本文还论述了中国如何通过战略耦合模式的动态调整实现从经济全球化的参与者到变革者的转变。本文认为这种角色转变,改变了西方发达经济体对后发经济体的预设发展路径,以及经典的产业梯度转移理论所预测的空间秩序,为全球化格局的变动带来新的重构动力与可能。最后,本文结合此次新型冠状病毒肺炎疫情全球爆发带来的影响对未来经济全球化发展存在的可能路径进行分析,并从经济地理学视角为中国未来经济全球化发展道路选择提供了参考建议。

By comparing topology structure of various copper-containing product trade network, this article comprehensively describes the global flow of copper resources and copper trade relations among countries or regions, which is conducive to enhancing the understanding of different countries and regions’ comparative advantages in the global value chain and promoting the sustainable use of resources. We build 5 types of global copper-containing product trade networks using bilateral trade data of copper ore, blister, refined copper, copper semis and copper scrap in the year of 2017. The data are collected from UNCOMTRADE and ITC Trade map database. Since the data are too huge to analyse, we first identify the backbone network using Top $ N $ method to simplify data and keep as much information as possible at the same time. Top2, Top2, Top3, Top10, and Top4 networks have been identified to represent the integral network of copper ore, blister, refined copper, copper semis and copper scrap respectively. After that, we adopt network analysis methods such as community detection to study the topology structures of each type of global copper-containing product trade networks, and discuss their similarities and differences. The main conclusions are as follows. 1) Since 2001, the global trade quantities of copper-containing products have increased steadily, indicating that the demand for copper resources for world economic development has been increasing continuously. Among them, the trade quantities of copper ore are the largest, followed by refined copper, and blister is the smallest. The pattern of supply and demand of 5 copper-containing products trade is different. 2) Trade relations mainly occur between countries and regions with higher industrialization level or better industrial system in the copper resource field. And there are obvious differences in the topological structure of 5 copper-containing product trade networks. 3) According to the results of community detecting algorithm, these networks can be divided into a range of communities from 4 to 8 with the module degree between 0.216 and 0.482. Most countries and regions belong to different communities in five types of trade networks due to difference in resource endowments and industrialization development stages. 4) China has huge demand for copper resource. In the trade network of copper ore, blister, refined copper and copper scrap, countries related to China’s demand formed the largest community, indicating that it occupies an important position in the global copper trade, and reflecting problems of Chinese copper resources such as the low self-sufficiency rate and large dependence on other countries and regions. China should maintain good cooperative relations with the countries and regions within the same community to reduce the supply risk of copper resources.

基于产业链视角研究铜贸易网络，构建了2017年铜矿石、粗铜、精炼铜、铜材和废杂铜5类含铜产品的全球贸易网络，对比产业链上各环节产品的贸易网络的拓扑结构，以全面刻画铜资源的全球流动以及国家（地区）之间的铜贸易关系。主要结论如下:① 2001年以来，全球含铜产品贸易重量稳定增长，其中铜矿石贸易重量最大，精炼铜次之。② 5类含铜产品贸易网络的拓扑结构存在明显差异，根据社区发现算法可划分为4~8个组团，模块度在0.216~0.482之间。由于资源禀赋和工业体系发展程度不同，大部分国家（地区）在5类贸易网络中分属于不同的组团。③ 中国对铜资源的需求巨大，围绕着中国的需求产生的贸易关系在铜矿石、粗铜、精炼铜、废杂铜4类贸易网络中都构成第一大组团，分别包含47、102、120、135个国家（地区），表明中国在全球铜贸易中占有重要地位，但也反映了中国铜资源自给率低、对外依存度大等问题。

The multi-level perspective and multi-scalar city network have gradually become the critical pathways to understand spatial interactions and linkages. The road linkages represent distinguished characteristics of spatial dependence and distance decay, which is of great significance in depicting spatial relationships at regional scale. Based on the data of highway passenger flows between prefecture-level administrative units, this paper tries to identify the functional structures and regional impacts of China's city network, and further explores the spatial organization patterns of the existing functional regions, aiming to deepen the understanding of city network structure and provide new cognitive perspectives for the extant research. The empirical results are shown as follows: (1) It is immediately visible that the highway flows are extremely concentrated on the mega-regions of eastern coastal China and major economic zones in central and western China. And city networks based on highway flows demonstrate strong spatial dependence and hierarchical characteristics, which to a large extent has spatial coupling with the distributions of major mega-regions in China. It is a reflection of spatial relationships at regional scale and core-periphery structure. (2) A total of 19 communities that belong to important spatial configurations are identified through community detection algorithm, and we believe that they are urban economic regions within urban China. Their spatial metaphors can be concluded in three aspects. Firstly, many communities have the same boundaries with provincial level administrative units, which reveals that significant administrative region economy still exists in contemporary China. Secondly, trans-provincial linkages can be formed through spatial spillover effects of mega-regions within specific communities. Thirdly, cities located in the marginal areas of provinces and attracted by powerful center cities in neighboring provinces may become increasingly disconnected with their own provinces and be enrolled into communities of neighboring provinces, which make contribution to the formation of the trans-provincial core-periphery structures. (3) Each community, with its distinguished city network system, demonstrates strong spatial dependence and various spatial organization patterns. Regional patterns have emerged with the features of a multi-level, dynamic and networked system. (4) From the morphology perspective, the spatial pattern of regional city networks can be basically divided into monocentric structure, dual-nuclei structure, polycentric structure and low-level equilibration structure, with the monocentric structure as the major type.

多视角和多尺度城市网络逐渐成为认识空间关系的主要途径。公路流数据具有显著的空间依赖性和距离衰减特性,对于刻画区域尺度空间关系具有重要意义。基于全国地级行政单元间的公路客运流,论文尝试刻画中国城市网络功能结构和区域效应,并对其空间组织模式进行特征提取和规律挖掘,以期能够为城市网络研究提供新的方法支撑和认知视角。研究结果表明：① 基于公路流的城市网络空间形态表现出强烈的空间依赖性和层级特征,与中国主要城市群分布存在较大程度的空间耦合,更多体现的是区域尺度的空间关系及核心—外围组合关系;② 通过社区发现算法识别出19个城市经济区,其空间内涵主要包括行政区经济、巨型区域溢出效应和核心—边缘结构等;③ 不同地域系统内城市网络自成体系,表现出显著的空间依赖性和多元的空间组织模式,多层次、流动性和网络化的地域系统格局凸显;④ 从空间形态上看,区域城市网络空间结构大致可划分为单中心结构、双核心结构、多中心结构和低水平均势结构等区域关联形态,并以单中心发育模式为主。

Community detection is often used to understand the structure of large and complex networks. One of the most popular algorithms for uncovering community structure is the so-called Louvain algorithm. We show that this algorithm has a major defect that largely went unnoticed until now: the Louvain algorithm may yield arbitrarily badly connected communities. In the worst case, communities may even be disconnected, especially when running the algorithm iteratively. In our experimental analysis, we observe that up to 25% of the communities are badly connected and up to 16% are disconnected. To address this problem, we introduce the Leiden algorithm. We prove that the Leiden algorithm yields communities that are guaranteed to be connected. In addition, we prove that, when the Leiden algorithm is applied iteratively, it converges to a partition in which all subsets of all communities are locally optimally assigned. Furthermore, by relying on a fast local move approach, the Leiden algorithm runs faster than the Louvain algorithm. We demonstrate the performance of the Leiden algorithm for several benchmark and real-world networks. We find that the Leiden algorithm is faster than the Louvain algorithm and uncovers better partitions, in addition to providing explicit guarantees.

Brain regions in the mammalian cerebral cortex are linked by a complex network of fiber bundles. These inter-regional networks have previously been analyzed in terms of their node degree, structural motif, path length and clustering coefficient distributions. In this paper we focus on the identification and classification of hub regions, which are thought to play pivotal roles in the coordination of information flow. We identify hubs and characterize their network contributions by examining motif fingerprints and centrality indices for all regions within the cerebral cortices of both the cat and the macaque. Motif fingerprints capture the statistics of local connection patterns, while measures of centrality identify regions that lie on many of the shortest paths between parts of the network. Within both cat and macaque networks, we find that a combination of degree, motif participation, betweenness centrality and closeness centrality allows for reliable identification of hub regions, many of which have previously been functionally classified as polysensory or multimodal. We then classify hubs as either provincial (intra-cluster) hubs or connector (inter-cluster) hubs, and proceed to show that lesioning hubs of each type from the network produces opposite effects on the small-world index. Our study presents an approach to the identification and classification of putative hub regions in brain networks on the basis of multiple network attributes and charts potential links between the structural embedding of such regions and their functional roles.