The state of social science research on COVID-19.

Research on COVID-19 has proliferated rapidly since the outbreak of the pandemic at the end of 2019. Many articles have aimed to provide insight into this fast-growing theme. The social sciences have also put effort into research on problems related to COVID-19, with numerous documents having been published. Some studies have evaluated the growth of scientific literature on COVID-19 based on scientometric analysis, but most of these analyses focused on medical research while ignoring social science research on COVID-19. This is the first scientometric study of the performance of social science research on COVID-19. It provides insight into the landscape, the research fields, and international collaboration in this domain. Data obtained from SSCI on the Web of Science platform was analyzed using VOSviewer. The overall performance of the documents was described, and then keyword co-occurrence and co-authorship networks were visualized. The six main research fields with highly active topics were confirmed by analysis and visualization. Mental health and psychology were clearly shown to be the focus of most social science research related to COVID-19. The USA made the most contributions, with the most extensive collaborations globally, with Harvard University as the leading institution. Collaborations throughout the world were strongly related to geographical location. Considering the social impact of the COVID-19 pandemic, this scientometric study is significant for identifying the growth of literature in the social sciences and can help researchers within this field gain quantitative insights into the development of research on COVID-19. The results are useful for finding potential collaborators and for identifying the frontier and gaps in social science research on COVID-19 to shape future studies.

Thermally stable core-shell Ni/nanorod-CeO2@SiO2 catalyst for partial oxidation of methane at high temperatures.

During partial oxidation of methane (POM), the greatest challenge is to maintain the thermal stability of the catalyst at high temperatures. One of the most effective ways to improve thermal stability is to construct core-shell structure. Herein, using a microemulsion method, we synthesized a core-shell Ni/nanorod-CeO2@SiO2 catalyst, in which the Ni nanoparticles were supported on the CeO2 nanorods and encapsulated by SiO2 shells. Based on a series of characterizations, we found that the Ni particles are of nanosize (2.2 nm) and the thickness of the SiO2 shell is about 8 nm in the core-shell catalyst. Moreover, the Ni/nanorod-CeO2@SiO2 catalyst can perfectly maintain rod-like structures of the CeO2 support and enhance interaction between the metal Ni and CeO2, significantly reducing the sintering of metal Ni particles at high temperatures. Therefore, the as-prepared Ni/nanorod-CeO2@SiO2 catalyst shows high catalytic activity and good thermal stability during the POM reaction.