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1.
考虑一个加法和乘法白噪声驱动的一维系统,给出相应的非线性随机微分方程,并推导了两种噪声关联过程的福克─普朗克方程.通过对其定态解的讨论,我们将看到噪声的关联对定态几率分布的影响.  相似文献   

2.
用一种新变换方法将关联噪声化为两个随机等价的独立噪声,从而可以使用各种原来处理两相独立噪声的随机动力学方法.对关联白噪声和关联O-U噪声驱动系统分别建立了福克-普朗克方程,并举例解出定态几率分布.  相似文献   

3.
关联色噪声驱动的线性系统的统计分析   总被引:1,自引:0,他引:1  
周小计  曹力 《华中理工大学学报》1997,25(12):102-104,108
精确计算了关联时间的为τ1和τ2的两相关O-U噪声所驱动线性系统的关联函数、功率谱及定态几率分布,发现:a.噪声间关联强λ对系统的关联函数、功率谱及定态几率分布都有很大的影响;b。当驱劝两O-U噪声的白噪声间接在联时间τ和两O-U噪声的自关联时间的相等(τ=τ1=τ2)时,直接关联和间接关联所计算出来的关联函数、功率谱及定态几率分布是相同的:c.在完全负关联(λ=-1),且各噪声的关联时间和强度都  相似文献   

4.
应用具有负关联噪声驱动系统的一般福克-普朗克方程,研究了具有负关联的加法和乘法高斯白噪声驱动的双稳系统,导得了该情形下的福克-普朗克方程.比较了双稳系统在正关联和负关联的高斯白噪声驱动下,定态几率分布和极值位置的变化,以及有关的各参数对定态几率分布单双峰转变的影响.从中发现了不少新的有意义的现象  相似文献   

5.
用一种新变换方法将关联噪声化为两个随机等价的独立噪声,从而可以使用各种原来处理两相独立噪声的随机动力学方法。对关联白噪声和关联O-U噪声驱动系统分别建立了福克-普朗克方程,并举例解出定态几率分布。  相似文献   

6.
推导了在关联噪声驱动下分子马达定态几率流的表达式,通过解析计算和数值模拟得到如下结果:加性白噪声不能驱动分子马达产生定向运动,定态几率流的方向取决于积分值δ,且在一维余弦势场中,定态几率流随着噪声关联参数的变化与噪声强度大小有关,不论噪声间是正关联或负关联,当内噪声强度一定,随着外噪声强度的增强,定态几率流增大,最终达到一个饱和值。  相似文献   

7.
研究了由两个双态噪声驱动的随机系统。给出了该随机系统的几率密度方程组,借助几率密度的随机刘维方程和对双态噪声变换,求得了近似几率密度方程。运用这种方法导出了随机的化学反应系统的近似几率密度方程。利用“Hanggi-likeansatz”求得了此化学反应的近似Fokker-planck方程及其定态解。  相似文献   

8.
精确计算了关联时间为τ1和τ2的两相关O-U噪声所驱动线性系统的关联函数、功率谱及定态几率分布.发现:a.噪声间关联强度λ对系统的关联函数、功率谱及定态几率分布都有很大的影响;b.当驱动两O-U噪声的白噪声间的关联时间τ和两O-U噪声的自关联时间相等(τ=τ1=τ2)时,直接关联和间接关联所计算出来的关联函数、功率谱及定态几率分布是相同的;C.在完全负关联(λ=-1),且各噪声的关联时间和强度都相等时,系统的关联函数、功率谱及相对涨落变为0,即确定论情形.  相似文献   

9.
将加法色噪声驱动的系统的定态几率分布展开理论推广到乘法色噪声系统中,计算了单模染料激光色损失模型的定态几率分布,与P.Jung等用统一色噪声近似所计算的结果相比,本文所得的结果与实验结果要符合得好一些.  相似文献   

10.
研究了由O-U加性噪声驱动的平方双稳热系统,首先将系统的郎之万方程扩大维数,然后作变量代换,最后进行拟合成平方双稳势,从而精确计算出系统的定态几率分布及二阶矩,揭示了噪声强度对定态几率分布的影响,指出定态几率分布对关联时间τ不敏感,研究还发现二阶矩随噪声强度的变化曲线存在一个极小值。  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

14.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

15.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

16.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

17.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

18.
For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the  相似文献   

19.
Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of  相似文献   

20.
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with  相似文献   

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