具无界时滞非自治平方Logistic模型的全局吸引性

考虑非自治平方 L ogistic模型 Δxn=rnxn(1- bxn- kn- cxn- kn2 ) ,n=0 ,1,2… ,其中 { rn}为非负实数列 ,b≥ 0 ,c>0 ,{ kn}是非负整数列 ,{ n- kn}非单调递减 ,且 limn→∞(n- kn) =∞ ,给出了保证其每一正解 { xn}满足 limn→∞xn=x的一族充分条件 (其中 x是正平衡点 ) 。

具无界时滞非自治Logistic模型的全局吸引性(英文)

考虑非自治Ｌｏｇｉｓｔｉｃ模型△ｘｎ ＝ ｐｎｘｎ（１ － ｘｎ－ ｋｎλ）， ｎ ＝ ０，１，…， （１）其中｛ｐｎ｝ｎ０为非负实数列，｛ｋｎ｝ｎ０为非负整数列且ｌｉｍｎ→∞（ｎ－ ｋｎ）＝ ∞，ｌｉｍ ｓｕｐｎ→∞ ｋｎ＝ ∞，λ为正常数．我们获得了方程（１）的平衡点λ全局吸引的新的充分条件，改进了文［５］的相应结果．

随机非自治Logistic模型

该文主要利用马尔可夫骨架过程理论和方法研究在随机干扰下,非自治Logistic模型:x′(t)=rx(t)(1-(X(t))/(K(t)))(K(t)>0).得到了模型的一维分布、稳定性条件以及渐近性质.

具时滞的非自治广义Logistic模型的研究

本文研究具时滞的非自治广义Logistic模型，利用非线性常数变易公式，得到该方程平凡解是全局指数渐近稳定的充分条件．

一类非自治的Logistic生长曲线及其应用

通过对决定单种群或有机体相对生长速率的机理进行研究 ,引入了一类非自治的 L ogistic生长方程 ,对其解的性质进行了系统研究。结果表明 ,该模型不仅可以拟合受密度与时间两个因素限制的生长过程 。

一类非自治SIS传染病模型的持续性

考虑了一类Logistic种群增长的非自治SIS传染病模型 这个模型的所有参数是与时间相关的。证明了在某些条件下系统是持续的,建立了关于相应周期系统正周期解的存在性与稳定性的条件。

食饵种群为Logistic模型的捕食者食系统的持久性

考虑食饵为Logistic模型的捕食者-食非自治系统,证明了该系统在某些条件下是持久的.而且,若该系统是周期系统,在某些条件下,它们存在正周期解且是全局渐近稳定的.

非自治的离散Smith方程的全局吸引性

QinqinZhang和ZhanZhou在文献 [1]中获得了方程xn+ 1=xnexp(rn(1-xn) )收敛于 1的充分条件。离散的非线性型Smith方程中 {rn}为一个非负实数序列 ,k ,β∈ (0 ,+∞ ) ,初值x0 >0 ,从而获得了满足条件的Smith方程的任意解{xn}关于正平衡解k全局吸引的充分条件是 : ∞n =0rn =∞且Lim n∞suprn ≤ 2。其结果推广了文 [1]等的结果。

Behavioral responses of blue sheep(Pseudois nayaur) to nonlethal human recreational disturbance

Nonlethal human recreational activities have been confirmed to have negative effect on wild animals in a number of ways,including changes in behaviors,avoidance of suitable habitats and declines in breeding success.Studies on the anti-disturbance mechanism of wild animals to human disturbance can provide valuable knowledge to the management of wild animals and the evolutionary mechanisms of behavioral adaptation to their habitats.To evaluate how blue sheep(Pseudois nayaur) would react to nonlethal human recreational disturbance,we studied their anti-disturbance strategy towards human disturbance in Suyukou National Forest Park(SNFP),Helan Mountains,Yinchuan of Ningxia Hui Autonomous Region.Using multinomial logistic regression models(MLRMs),we sought to answer two questions:(1) which kind of human recreational behavior would evoke the most serious anti-disturbance behaviors in blue sheep;and(2) how would various ecological factors influence the anti-disturbance strategy of blue sheep to human recreational disturbance? We collected 10 habitat and population variables and evaluated three kinds of reaction of blue sheep-no response,vigilance and flight.A total of 921 observations qualified to enter MLRMs.We found that habitat type(HT),gender(GEN),head direction(HD),visibility index(VI),and disturbance source(DS) were the five variables that significantly influenced the intensity of reactions of blue sheep.Blue sheep were more alert to tourists than to vehicles,and roads were the habitat type that caused the most intensive reaction of alertness where human disturbance was the highest.Females were more vigilant than males.Blue sheep might feel safer when staying in open habitat,and taking a front head direction provided them with the highest vigilance.Based on these results,we present suggestions to SNFP for the management of ecotourism and blue sheep conservation.