中文摘要：

区域双核结构模式是一种重要的经济地理现象。基于新经济地理学的研究视角和分析框架,论文构建模型,分析了规模经济和对外贸易推动区域双核结构模式的生成过程和经济机理。模型研究表明,规模经济和对外贸易是塑造区域双核结构模式的基本力量：规模经济的增强放大了本地市场效应,导致了区域核心城市的出现;对外贸易影响着沿海地区的经济地理优势,决定着港口区位核心城市和内陆地区核心城市的并存。山东半岛济南—青岛双核结构模式生成过程的实证研究也表明,双核结构模式是制造业活动完成由以手工业为主导向现代化大生产为主导转变、区域发展环境完成由相对封闭向相对开放转变之后才产生的经济地理现象。

英文摘要：

The dual-core spatial structure is an important economic-geographical phenomenon.From the perspective of new economic geography,based on analytical frameworks,a model is proposed to analyze the economic mechanism of how economies of scale and foreign trade promote the formation of a dual-core structure.Subsequently,taking Jinan-Qingdao dual-core structure in Shandong peninsula as an example,empirical research is conducted.The model shows that economies of scale and foreign trade are the two basic factors in shaping the dual-core spatial structure in the regional development.First,at early stages,with small returns of local economic activities,the centripetal forces are weak relative to the centrifugal forces,leading to an even distribution of small cities of about the same size.Then,the growth of economies of scale for manufacturing magnifies the home market effect,causing the concentration of production factors in the district with a large consumer market.As a result,economies of scale are the key to the emergence of a regional big city,which in turn is a prerequisite for the formation of regional dual-core structure.Second,foreign trade improves the economic-geographical position of coastal areas,serving as a direct driving force for dual-core structure formation.When the foreign trade volume is small,the spatial structure has a core-periphery form.With gradual deepening of foreign trade relation,the inland city and the port city both become economically important at the same time.The model predicts that if foreign demand becomes larger and larger,the dual-core structure will eventually collapse,and the economies of the port city will reach a new equilibrium.The empirical study of the evolving process of urban spatial structure in Shandong Peninsula shows that,Jinan-Qingdao dual-core spatial structure emerges only after modern manufacturing dominates the regional economies and the regional business environment changes from a closed and autarky economy to an open economy.