Volume 8 (2023): Issue 1 (January 2023)

This paper takes the degree of debt concentration and product market competitive advantage as intermediary variables to explore the internal mechanism of the impact of CSR fulfilment on firm debt risk. It is found that the fulfilment of CSR can reduce the debt risk of firms by dispersing the degree of debt concentration and enhancing the competitive advantage of product market. The mediating effect of the degree of debt concentration has a direct impact on the competitive advantage of a product market and is particularly obvious in private firms and firms in the eastern region of China.

As the primary killer of health, the class of infectious diseases is the greatest threat to humanity. At present, international methods of studying the large-scale spatial transmission of sudden infectious diseases from the perspective of dynamics can be divided into two categories. On the one hand, top international biomedical and medical teams discuss the restraining effects of some prevention and control strategies on infectious diseases, such as smallpox, malaria, hand, foot and mouth disease and pandemic influenza, from the perspective of pragmatism. On the other hand, researchers in theoretical physics and network science tend to use compound population network models to explore the internal dynamic mechanism of spatial transmission of infectious diseases. This paper establishes a Lotka–Volterra dispersal predator–prey system in a patchy environment. It shows the existence of model boundary equilibria and asymptotic stability under an appropriate condition. This paper adopts the method of global Lyapunov function and the results of graph theory. We also consider a predator–prey dynamical model in a patchy environment, where the prey and predator individuals in each compartment can travel among n patches.

This article describes and illustrates Paris panxiensis (J. L. Liu) Y. Yuan & J. L. Liu from a morphological perspective, based on field survey, indoor potting and garden cultivation, and observations gleaned from these activities. This variety is closely related to P. delavayi Franch, P. daliensis H. Li et V. G. Soukup, P. lihengiana G. W. Hu & Q. F. Wang and P. polyphylla Smith var. stenophylla Franch, but differs from these in having the following characteristics: flower parts with a basic number of 4–8, petals far shorter than sepals, linear-virgate, bottom linear, gradually thickening upward, erect, never extend or curved, apex rounded or obtuse, and connectivum projecting.