Numerical investigation on the penetration process of steel casings in riprap environment of estuarine mudflats.

The widespread distribution of riprap in estuarine mudflats has brought significant challenges to the penetration construction of steel casings. To reveal the effects of casing length, diameter and wall thickness on the stress and deformation, as well as the deformation characteristics and mechanical behaviors of the steel casing during the sinking process, the paper utilizes finite element method to construct a three-dimensional numerical model of the collision between steel casings and riprap in mudflat. The research results indicate that longer steel casing has better crushing effect on the riprap, smoother deflection curve of the casing body and smaller deformation at the casing end under the same casing diameter and wall thickness conditions.

Depression and Anxiety Among Quarantined People, Community Workers, Medical Staff, and General Population in the Early Stage of COVID-19 Epidemic.

We described the prevalence of anxiety and depression related to COVID-19 pandemic among different types of population and examined their potential risk factors. A cross-sectional survey was conducted to collect demographic characteristics, exposure histories, and many other concerns about COVID-19. The Zung's self-rating anxiety scale (SAS) and self-rating depression scale (SDS), followed by a four-step multiple logistic regression analysis was performed to identify factors associated with mental health outcomes.