基于上述特征事实，作者构建了一个包含货币扩散的动态量化贸易模型，从而将贸易成本、铸币决策、技术进步等因素纳入到分析古典时代经济地理的转变中去。此处，我们不对模型的细节做过多阐述，仅大致描述模型的构建思路和均衡条件。

作为宇宙中一颗耀眼的行星，地球是人类共同的家园！地球科学是一门古老而经典的基础学科，围绕宇宙演变规律和圈层相互作用，不断探索求真，已经发展成为涵盖地质学、地球化学、地球物理、大气科学、海洋科学、环境科学、地理科学以及交叉科学的综合性学科；聚焦行星演化 ...

凯茜·伍德旗下的旗舰交易所交易基金（ETF）已从贸易战恐慌的深渊中强劲反弹，自四月初以来涨幅超过50%。然而，此番反弹非但未能恢复投资者的信心，反而招致了普遍的怀疑。

Join Tony Bott and his dear friend Annei Lee for an enchanting evening of music under the stars at Cotton's. The duo will perform a delightful mix of pop, R&B, jazz, and bossa nova, creating the perfe ...

The attacks continued. The Natanz nuclear facility came under sustained bombardment -- if one strike failed, more followed hours later. By morning, Iran confirmed the death of Hossein Salami, ...

Recently, multiple cross-border railway projects, including the Ganqmod-Gashuun Sukhait Railway, have achieved significant milestones. China is steadily building a modern railway network that connects ...