Dynamical behavior of stochastic multigroup S-DI-A epidemic models for the transmission of HIV     

Qun Liu  Daqing Jiang  Tasawar Hayat  Ahmed Alsaedi 《Journal of The Franklin Institute》2018,355(13):5830-5865

In this paper, we study two stochastic multigroup S-DI-A epidemic models for the transmission of HIV. For the stochastic S-DI-A epidemic model with periodic coefficients, we first obtain sufficient conditions for persistence in the mean of the disease. Then in the case of persistence, we show that the model admits a positive T-periodic solution by using Khasminskii theory of periodic solution. Moreover, we establish sufficient conditions for exponential extinction of the infectious disease. For the stochastic S-DI-A epidemic model disturbed by both white and telegraph noises, we first establish sufficient conditions for persistence in the mean of the disease. Then in the case of persistence, we obtain sufficient conditions for the existence of a unique ergodic stationary distribution of the positive solutions by constructing a suitable stochastic Lyapunov function with regime switching and we also obtain sufficient conditions for exponential extinction of the system with regime switching.  相似文献   

为了忘却的写作:双雪涛、班宇、郑执创作论     

公言海 《扬州职业大学学报》2023,(1):16-20

双雪涛、班宇、郑执借助东北下岗潮中的父辈故事,书写了独属于子辈的伤痕。下岗潮后人们由富足坠落,抵达贫穷,此种贫穷因其内含的对比与落差而成为敏感少年心中隐痛的伤痕。三位作家在创作中通过重新梳理过去、发掘父辈的力量与信念、植入真善美的理念三种方式,疗治自我的伤痕。但是自我疗治式的写作也有着写作单一、片面的“副作用”,加之写作动机的消解,三位作家在短暂的创作爆发后不可避免地步入了“沉寂”。  相似文献