In this paper, we investigate the impact of digital finance on corporate innovation based on Chinese A-share listed companies from 2011 to 2017. We find that digital finance has a significant promotion effect on corporate innovation. The development of digital finance promotes enterprise innovation, increasing the number of patent applications and authorizations. The development of digital finance mainly promotes corporate innovation through two channels. First, digital finance improves bank competition and credit availability to promote corporate innovation; second, digital finance reduces financing constraints and financing costs of enterprises to promote corporate innovation. We also conduct a rich set of robustness tests and obtain consistent conclusions.

With the global integration development, the linkage between countries is strengthened in the dynamic spillover effects between BRIC and G7 from 2009 to 2020. We find that G7 is the exporter of risk, and BRIC is the receiver of the risk. We build the spillover model from the DAG-SVAR model. In the static spillover analysis, the net spillover of G7 is higher than that of BRIC. In the dynamic spillover analysis, the total systemic spillover is highly consistent with the world’s risk events. We also consider the directional spillover between G7 and BRIC, and find the volatility spillover of G7 to other markets is higher than that of BRIC. Furthermore, we use the European Debt Crisis, the China-US Trade War, and the Covid-19 Pandemic to study the spillover network’s dynamic evolution. We find that the global financial market’s spillover network is enhanced, and the volatility net spillover increased rapidly after the corresponding events. Specifically, after the Wuhan lockdown, China’s net spillover increased sharply to 264%, ranked first globally, and the net volatility spillover connectedness increased substantially after the Covid-19 Pandemic.

This paper investigates the impact of stock liquidity on firm value in the time of COVID-19 pandemic. Using data from A-share listed companies in China, we calculate the firm value of Cumulative Abnormal Returns through the event study method and stock liquidity by the Amihud illiquidity. We find that significant negative relationships between stock liquidity and firm value exist in the first three days of the COVID-19 outbreak, while significant positive relationships in the following days. We also find that these negative relationships are more significant in severely impacted regions, small companies, and non-state-owned enterprises.

A simple and flexible microfluidic strategy is developed to controllably fabricate magnetic, hierarchical meso-/macroporous SiO₂ microparticles for enhanced water decontamination.