摘要
研究了由乘性白噪声和加性白噪声驱动的非对称双稳系统中,势阱的非对称性对两个不同方向的平均首次穿越时间的影响.发现在非对称双稳系统中,两个不同方向的平均首次穿越时间是与初始状态有关.此外,对一维非对称达芬模型的平均首次穿越时间进行了研究.数值结果表明:(1)非对称双稳系统的平均首次穿越时间对初始状态有“记忆性”;(2)噪声强度对两个不同方向的平均首次穿越时间T+(xs1→xs2)和T-(xs2→xs1)的影响是不同的:lnT--D曲线上存在峰值,出现了“共振”现象,而lnT+-D曲线是单调的;(3)势阱的非对称性r对T+(xs1→xs2)和T-(xs2→xs1)的影响是不同的:lnT--r曲线上存在极小值,出现了“抑制”现象,而lnT+-r曲线是单调的.
In this paper, the effects of asymmetry of the potential on the mean first-passage times (MFPTs) in two opposite directions are investigated in an asymmetric bistable system driven by multiplicative noise and additive noise. We find that the MFPTs in two opposite directions are no longer symmetric in an asymmetric bistable system. Furthermore, we calculate the MFPFs of an asymmetric Duffing model. Numerical results show that: (1) The MFPTs depend on the initial states in the asymmetric bistable system, namely, T+ (x(s1) -> x(s2)) is not equal to T-_(x(s2) -> x(s1)). (2) The effects of noise intensity on the MFPTs T+ (x(s1) -> x(s2)) and T- (x(s2) -> x(s1)) are different in the same kind of parameter plane. There exists a peak on each of the curves of InT- versus D, as well as the 'resonant activation', while the variation of InT+ versus D is monotonic. (3) The influence of the asymmetry coefficient r on T+/- is entirely different. The curves of InT- versus r have mono-valleys but the variation of InT+ versus r is monotonically rising.
出处
《物理学报》
SCIE
EI
CAS
CSCD
北大核心
2005年第8期3480-3485,共6页
Acta Physica Sinica
基金
国家自然科学基金(批准号:10472091
10332030)
陕西省自然科学基金(批准号:2003A03)资助的课题~~
