Background: The infectious disease Coronavirus Disease 2019 (COVID-19) outbroke in 2019 spread to multiple countries.The quick spread of the virus and isolation strategies may trigger psychological problems.Our aim was to explore the dynamic network structure of the psychological state Black Tea before and during the epidemic.Methods: A web-based s

Collision is the main issue in Aprons safe transportation, including in the railway system.Sensor systems have been developed to detect obstacles to prevent a collision, such as using cameras.One disadvantage of the camera systems is that performance detection decreases in a not clean environment, like the target position behind the fogs.This paper

Pyrotechnic devices are widely used in modern aerospace engineering.One of the most effective types of pyrotechnic devices for Brake Shoes performing obstacle separation operations in aerospace engineering is linear shaped charges.The penetration efficiency of the cumulative jet into a metal plate varies depending on the distance to the obstacle, i