Abstract:As global scientific collaboration becomes increasingly interconnected and interdisciplinary, research collaboration networks have emerged as critical tools for assessing scientific impact and research productivity. International collaboration, often involving multiple countries and institutions, brings diverse perspectives and methodologies to tackle complex problems, thereby driving innovation and enhancing the impact of scientific outcomes. Clarivate’s Essential Science Indicators, which include highly cited and hot papers, highlight the novelty and great influence of these studies, serving as key metrics for evaluating research quality and impact. Recently, growing attention has been directed toward the collaborative patterns of high-impact papers, focusing on how various disciplinary, regional, and international collaboration models influence research output through analysis of collaborator relationships. This study leverages the Web of Science database and selects papers in the top 1% of Category Normalized Citation Impact (CNCI) as high-impact papers. A total of 5 997 high-impact papers in the field of Earth Sciences in China from 2003 to 2022 are analyzed. The study examines embedding characteristics and network structural features from three dimensions: collaboration type (domestic vs. international collaboration), collaboration distribution (primacy index and Gini coefficient), and collaboration dominance (leading roles in collaboration). From the perspectives of individual node behavior and unsupervised identification of network community structures, the study explores the structural characteristics of domestic and international collaboration networks. The results indicate that nearly 99% of high-impact papers are products of collaboration, with international collaboration (53.68%) slightly surpassing domestic ones(46.32%). Both domestic and international collaborations display uneven and concentrated distributions, with international collaboration showing a higher degree of concentration. China’s leadership in international collaborations has steadily grown, although the nature of its leading roles varies by partner country. Domestically, significant differences exist among institutions in their collaborative prominence. Both domestic and international research collaboration networks exhibit a "multi-core-periphery" structure. In the international network, the United States occupies the most central position, while domestically, the Chinese Academy of Sciences serves as the primary hub, acting as a key intermediary in the research collaboration ecosystem. To achieve high-quality scientific collaboration in China, targeted international collaboration policies should be developed to enhance the efficiency of scientific cooperation. Simultaneously, greater support should be provided to central domestic institutions to deepen cross-institutional research collaborations.
