The non-uniform transmission and network topological structure are combined to investigate the spreading behavior of susceptible-infected-susceptible （SIS） epidemic model. Based on the mean-field theory, the analyti...The non-uniform transmission and network topological structure are combined to investigate the spreading behavior of susceptible-infected-susceptible （SIS） epidemic model. Based on the mean-field theory, the analytical and numerical results indicate that the epidemic threshold is correlated with the topology of underlying networks, as well as the disease transmission mechanism. These discoveries can greatly help us to further understand the virus propagation on communication networks.展开更多
The presence of ethanol has an adverse effect on foam spreading,and ethanol fire is difficult to extinguish with aqueous fire-fighting foams.Thus,it is necessary to explore the foam formulation suitable for ethanol fu...The presence of ethanol has an adverse effect on foam spreading,and ethanol fire is difficult to extinguish with aqueous fire-fighting foams.Thus,it is necessary to explore the foam formulation suitable for ethanol fuels and study the spreading behavior of foam over ethanol surface.In the current work,stable foams based on hydrocarbon surfactant(SDS),fluorocarbon surfactant(FC1157),and polymers(XG)were prepared by using the compressed-air foam system.The spreading behaviors of foam on polar ethanol and non-polar heptane surface were observed and compared.Furthermore,the effects of stabilizer concentrations,foam flow rates and expansion ratios on foam spreading performance were investigated,respectively.The results indicate that aqueous SDS foam can spread on the heptane layer continuously,but it is difficult to cover the ethanol surface.The addition of XG and FC1157 can synergistically improve the spreading performance of aqueous foam over ethanol.Depending on stabilizer concentrations,there are remarkable differences in foam spreading behaviors.Besides,different foam application parameters including expansion ratios and foam flow rates significantly affect the foam spreading rate,despite the same foam formulation.The research methods and results guide the optimal design of foam formulations as well as the practical application of aqueous foam for ethanol fire extinguishment.展开更多
An ambient pressure-induced calcination process was proposed to prepare g-C3 N4 with different structures.The porcelain boat with designed porosity is used to control the ambient pressure to change the diffusion behav...An ambient pressure-induced calcination process was proposed to prepare g-C3 N4 with different structures.The porcelain boat with designed porosity is used to control the ambient pressure to change the diffusion behavior of the reaction molecules,thereby controlling the layer structure and rich pyridinic N content of g-C3 N4,thus renders superior lithium storage performance.展开更多
基金supported by the National Natural Science Foundation of China (60574036, 60774088)the Research Fund for the Doctoral Program of China (20050055013)+2 种基金the Program for New Century Excellent Talents in University of China (NCET)Tianjin Municipal Natural Science Foundation (08JCZDJC21900,08ZCKFGX00600, 08JCYBJC12300)Tianjin Municipal Research Foundation for the Universities (20071306).
文摘The non-uniform transmission and network topological structure are combined to investigate the spreading behavior of susceptible-infected-susceptible （SIS） epidemic model. Based on the mean-field theory, the analytical and numerical results indicate that the epidemic threshold is correlated with the topology of underlying networks, as well as the disease transmission mechanism. These discoveries can greatly help us to further understand the virus propagation on communication networks.
基金supported by the National Key Research and Development Program of China(2016YFB1200505)Jiangsu Key Research and Development Plan Project(BE2020663)the Anhui Key Research and Development Plan Project(No.1804a0802202)。
文摘The presence of ethanol has an adverse effect on foam spreading,and ethanol fire is difficult to extinguish with aqueous fire-fighting foams.Thus,it is necessary to explore the foam formulation suitable for ethanol fuels and study the spreading behavior of foam over ethanol surface.In the current work,stable foams based on hydrocarbon surfactant(SDS),fluorocarbon surfactant(FC1157),and polymers(XG)were prepared by using the compressed-air foam system.The spreading behaviors of foam on polar ethanol and non-polar heptane surface were observed and compared.Furthermore,the effects of stabilizer concentrations,foam flow rates and expansion ratios on foam spreading performance were investigated,respectively.The results indicate that aqueous SDS foam can spread on the heptane layer continuously,but it is difficult to cover the ethanol surface.The addition of XG and FC1157 can synergistically improve the spreading performance of aqueous foam over ethanol.Depending on stabilizer concentrations,there are remarkable differences in foam spreading behaviors.Besides,different foam application parameters including expansion ratios and foam flow rates significantly affect the foam spreading rate,despite the same foam formulation.The research methods and results guide the optimal design of foam formulations as well as the practical application of aqueous foam for ethanol fire extinguishment.
基金financial support from National Natural Science Foundation of China(Nos.51702046,51772050 and 51822202)the Program for Professor of Special Appointment(Eastern Scholar)at Shanghai Institutions of Higher Learning,State Key Laboratory for Modification of Chemical Fibers and Polymer Materials,Donghua University。
文摘An ambient pressure-induced calcination process was proposed to prepare g-C3 N4 with different structures.The porcelain boat with designed porosity is used to control the ambient pressure to change the diffusion behavior of the reaction molecules,thereby controlling the layer structure and rich pyridinic N content of g-C3 N4,thus renders superior lithium storage performance.
