Baogang Rare Earth Group received 5 new members December 27, 1995, making the total members of the group reach 14 and becoming the largest rare earth group in the world. Originally, some subsidiaries such as No. 3 Pla...Baogang Rare Earth Group received 5 new members December 27, 1995, making the total members of the group reach 14 and becoming the largest rare earth group in the world. Originally, some subsidiaries such as No. 3 Plant of Baotou Steel and Rare Earth Company (Baogang) joined the group as independent members. To straighten out the confusion, Baogang展开更多
This paper considers an SIRS epidemic model that incorporates constant immigrati on rate, a general population size dependent contact rate and proportional tran sfer rate from the infective class to susceptible class...This paper considers an SIRS epidemic model that incorporates constant immigrati on rate, a general population size dependent contact rate and proportional tran sfer rate from the infective class to susceptible class.A threshold parameter σ is identified. If σ≤1, the disease free equilibrium is globally stab le. If σ>1, a unique endemic equilibrium is locally asymptotically stable. For two important special cases of mass action incidence and standard incidence, global stability of the endemic equilibrium is proved provided the threshold is larger than unity. Some previous results are extended and improved.展开更多
文摘Baogang Rare Earth Group received 5 new members December 27, 1995, making the total members of the group reach 14 and becoming the largest rare earth group in the world. Originally, some subsidiaries such as No. 3 Plant of Baotou Steel and Rare Earth Company (Baogang) joined the group as independent members. To straighten out the confusion, Baogang
基金Supported by the Science and Technology Foundation of Zhejiang University(1 0 70 0 0 - 54430 1 )
文摘This paper considers an SIRS epidemic model that incorporates constant immigrati on rate, a general population size dependent contact rate and proportional tran sfer rate from the infective class to susceptible class.A threshold parameter σ is identified. If σ≤1, the disease free equilibrium is globally stab le. If σ>1, a unique endemic equilibrium is locally asymptotically stable. For two important special cases of mass action incidence and standard incidence, global stability of the endemic equilibrium is proved provided the threshold is larger than unity. Some previous results are extended and improved.
