We consider an epidemical model within soclally interacting mobile individuals to study the behaviors of steady states of epidemic propagation in 2D networks. Using mean-field approximation and large scale simulations...We consider an epidemical model within soclally interacting mobile individuals to study the behaviors of steady states of epidemic propagation in 2D networks. Using mean-field approximation and large scale simulations, we recover the usual epidemic behavior with critical thresholds δc and pc below which infectious disease dies out. For the population density δ far above δc it is found that there is linear relationship between contact rate λ and the population density δ in the main. At the same time, the result obtained from mean-field approximation is compared with our numerical result, and it is found that these two results are similar by and large but not completely the same.展开更多
Onset mechanism is one of the most fundamental issues in thermoacoustic field.However,the onset conditions and the phenomena happening in the onset process have not been well explained theoretically.In this paper,a no...Onset mechanism is one of the most fundamental issues in thermoacoustic field.However,the onset conditions and the phenomena happening in the onset process have not been well explained theoretically.In this paper,a novel model based on the circuit network analogy is proposed to predict the onset temperature of a standing-wave thermoacoustic engine.The activity and instability criteria are proposed to be the onset criteria in the model.The influences of the porosity of the heat exchanger and the stack,and the length of the resonant tube on the onset temperature are analyzed.The calculated results are in agreement with the experimental results,which indicates that the activity and instability criteria can be used to predict the onset conditions of a thermoacoustic engine.展开更多
基金The project supported by National Natural Science Foundation of China under Grant No. 50272022 and the Sunshine Foundation of Wuhan City under Grant No. 20045006071-40
文摘We consider an epidemical model within soclally interacting mobile individuals to study the behaviors of steady states of epidemic propagation in 2D networks. Using mean-field approximation and large scale simulations, we recover the usual epidemic behavior with critical thresholds δc and pc below which infectious disease dies out. For the population density δ far above δc it is found that there is linear relationship between contact rate λ and the population density δ in the main. At the same time, the result obtained from mean-field approximation is compared with our numerical result, and it is found that these two results are similar by and large but not completely the same.
基金supported by the National Funds for Distinguished Young Scientists of China (Grant No. 50825601)partly by the National Basic Research Program of China ("973" Program) (Grant No. 2010CB-227303)
文摘Onset mechanism is one of the most fundamental issues in thermoacoustic field.However,the onset conditions and the phenomena happening in the onset process have not been well explained theoretically.In this paper,a novel model based on the circuit network analogy is proposed to predict the onset temperature of a standing-wave thermoacoustic engine.The activity and instability criteria are proposed to be the onset criteria in the model.The influences of the porosity of the heat exchanger and the stack,and the length of the resonant tube on the onset temperature are analyzed.The calculated results are in agreement with the experimental results,which indicates that the activity and instability criteria can be used to predict the onset conditions of a thermoacoustic engine.
