The Coronavirus Disease 2019(COVID-19)highlights the importance of understanding and controlling the spread of the coronavirus between persons.We experimentally and numerically investigated an advanced engineering and...The Coronavirus Disease 2019(COVID-19)highlights the importance of understanding and controlling the spread of the coronavirus between persons.We experimentally and numerically investigated an advanced engineering and environmental method on controlling the transmission of airborne SARS-CoV-2-laden aerosols in the breathing microenvironment between two persons during interactive breathing process by combining the limited space air stability and a ventilation method.Experiments were carried out in a full-scale ventilated room with different limited space air stability conditions,i.e.,stable condition,neutral condition and unstable condition.Two real humans were involved to conducted normal breathing process in the room and the exhaled carbon dioxide was used as the surrogate of infectious airborne SARS-CoV-2-laden aerosols from respiratory activities.A correspondent numerical model was established to visualize the temperature field and contaminated field in the test room.Results show that the performance of a ventilation system on removing infectious airborne SARS-CoV-2-laden aerosols from the interpersonal breathing microenvironment is dependent on the limited space air stability conditions.Appropriate ventilation method should be implemented based on an evaluation of the air condition.It is recommended that total volume ventilation methods are suitable for unstable and neutral conditions and local ventilation methods are preferable for stable conditions.This study provides an insight into the transmission of airborne SARS-CoV-2-laden aerosols between persons in ventilated rooms with different limited space air stability conditions.Useful guidance has been provided to cope with COVID-19 in limited spaces.展开更多
In this paper the existence of discrete vector solutions with bounded second order quotientsfor the difference systems of nonlinear parabolic system is established by the fixed point technique,and then the absolute an...In this paper the existence of discrete vector solutions with bounded second order quotientsfor the difference systems of nonlinear parabolic system is established by the fixed point technique,and then the absolute and relative stability for the general difference schemes is justified in thesense of continuous dependence of the discrete vector solution of the difference schemes on thediscrete data of the original problems.展开更多
基金supported by the National Natural Science Foundation of China(No.51378186)the National Science and Technology Support Program(No.2015BAJ03B00)the China Scholarship Council(No.201806130150)。
文摘The Coronavirus Disease 2019(COVID-19)highlights the importance of understanding and controlling the spread of the coronavirus between persons.We experimentally and numerically investigated an advanced engineering and environmental method on controlling the transmission of airborne SARS-CoV-2-laden aerosols in the breathing microenvironment between two persons during interactive breathing process by combining the limited space air stability and a ventilation method.Experiments were carried out in a full-scale ventilated room with different limited space air stability conditions,i.e.,stable condition,neutral condition and unstable condition.Two real humans were involved to conducted normal breathing process in the room and the exhaled carbon dioxide was used as the surrogate of infectious airborne SARS-CoV-2-laden aerosols from respiratory activities.A correspondent numerical model was established to visualize the temperature field and contaminated field in the test room.Results show that the performance of a ventilation system on removing infectious airborne SARS-CoV-2-laden aerosols from the interpersonal breathing microenvironment is dependent on the limited space air stability conditions.Appropriate ventilation method should be implemented based on an evaluation of the air condition.It is recommended that total volume ventilation methods are suitable for unstable and neutral conditions and local ventilation methods are preferable for stable conditions.This study provides an insight into the transmission of airborne SARS-CoV-2-laden aerosols between persons in ventilated rooms with different limited space air stability conditions.Useful guidance has been provided to cope with COVID-19 in limited spaces.
文摘In this paper the existence of discrete vector solutions with bounded second order quotientsfor the difference systems of nonlinear parabolic system is established by the fixed point technique,and then the absolute and relative stability for the general difference schemes is justified in thesense of continuous dependence of the discrete vector solution of the difference schemes on thediscrete data of the original problems.
