高能碰撞中的间歇与混沌

通过研究随机级联α模型,证明了对于固定的动力学起伏强度,多粒子末态相空问有间歇现象,但是没有混沌现象.只有当不同事件的动力学起伏强度不同时才能同时观察到多粒子末态的间歇与混沌行为.这说明,在高能碰撞中,分形与混沌是两个相互联系但又不同的非线性动力学性质.     

阶乘矩的归一化与间歇指数对平均横动量的依赖性

本文对阶乘矩的两种不同归一化进行了细致的分析,发现在固定多重数以及间歇程度不依赖于多重数的情况下,两种归一化得到的间歇指数相等.对于多重数不固定,而间歇程度与多重数有关的情况,给出了两种不同归一化得到的间歇指数用动力学间歇指数表示的公式.本文还在间歇程度依赖于单事件平均横动量的假定下,全面复现了实验上观察到的间歇对横动量截断的依赖性,证实了平均横动量对于决定间歇程度有重要意义.     

阶乘矩的归一化与间歇指数对平均横动量的依赖性

本文对阶乘矩的两种不同归一化进行了细致的分析,发现在固定多重数以及间歇程度不依赖于多重数的情况下,两种归一化得到的间歇指数相等。对于多重数不固定,而间歇程度与多重数有关的情况,给出了两种不同归一化得到的间歇指数用动力学间歇指数表示的公式。本文还在间歇程度依赖于单事件平均横动量的假定下,生面复现了实验上观察到的间歇对横动量截断的依赖性,证实了平均横动量对于决定间歇程度有重要意义。     

激光大气闪烁的间歇特征

 以小波变换法观察了湍流大气中激光光强起伏的间歇特征, 并用奇性测度进行了定量的描述。根据间歇性参量的周日变化规律发现：激光大气闪烁的间歇性存在于所有的时间和起伏条件下,并且保持稳定,间歇性参量约为0.1,基本不随起伏条件和时间变化。     

逐事件分析中高阶矩统计起伏的消除

逐事件分析是目前高能重离子碰撞研究中受到广泛注意的方法.由于单个事件的粒子数有限,在运用这一方法时,首先要解决统计起伏的消除问题.在现有文献中只讨论过低阶矩(最高到三阶)统计起伏的消除.本文研究了高阶矩中统计起伏的消除,给出了普遍公式.     

相对论重离子碰撞中逐事件横动量起伏的蒙特卡洛研究

用蒙特卡罗模型研究了相对论重离子碰撞中逐事件横动量起伏与多重数的关联, 发现蒙特卡罗产生器,HIJING,不能描述实验现象. 提出了一个简单的蒙特卡罗模型, 可以与实验一致, 有助于理解逐事件横动量起伏与多重数关联的动力学起源.     

高能强子–强子碰撞中喷注的产生与演化过程的动力学起伏

用蒙特卡洛方法对630GeV/c质子–反质子碰撞中的无偏样本、喷注事件样本和喷注内样本中的动力学起伏进行了研究.结果表明,喷注事件样本和电子–正电子对撞的全事件样本相似,近似地有各向同性的动力学起伏,而喷注内样本则和电子–正电子对撞的喷注一样,有类似于强子–强子碰撞软过程的各向异性动力学起伏.这表明,强子–强子碰撞中喷注的产生和演化分别和电子–正电子碰撞中喷注的产生和演化有类似的动力学性质.     

南海夏季沿岸内波与定点声起伏特征分析

利用2020年6月海南岛沿岸试验数据,分析内波及声能量起伏特征。试验海域以全日潮内波为主,并伴随有高频内波活动。内波活动引起360 Hz单频信号20 km定点声起伏峰峰值超过30 dB, 320～400 Hz线性调频信号起伏峰峰值超过15 dB。利用测量数据结合数值仿真,讨论了内波引起单频信号和线性调频信号呈现不同起伏特征的原因。结果表明:试验海域内波活动导致单频声场模态间干涉条纹出现移动,进而导致接收位置处特定频率的声能量出现大幅度的快速起伏;由于带宽内的平均作用,宽带信号的能量起伏远小于单频信号的能量起伏。当内波传播速度变化时,各内波成分在声传播路径上出现的时间和位置发生了变化,使得声场出现剧烈起伏的时间也随之变化。     

高能强子–强子碰撞喷注内部动力学起伏的自仿射分析

对CERN-SppS对撞机能区的质子–反质子碰撞事件中产生的喷注(微喷注)内部的动力学起伏进行了自仿射分析.按圆锥法判定由蒙特卡洛事件产生器产生的事件样本中的喷注(微喷注).通过一维阶乘矩的研究得到自仿射的赫斯特指数.按照所得到的赫斯特指数进行三维自仿射分析,在双对数图上得到较好的直线.从而进一步证明,喷注内部的动力学起伏近似地和SPS静止靶强子–强子碰撞中的动力学起伏一样,呈现为纵–横各向异性,而在横平面内各向同性.     

间歇现象与超软过程

本文从强子-强子碰撞过程中的间歇强度对各种物理参量的依赖性的实验数据出发,证明单事件平均横动量对于间歇强度有决定性作用,从而表明,间歇现象和近年来实验上发现的超软过程有紧密联系.     

Intermittency Phenomena and Super-soft Processes

Starting from the experimental data on the dependence of intermittency phenomena on various physical parameters,it is shown that the average transverse momentum per event plays a decisive role in determining the intermittency strength.This means that intermittency phenomena is closely related to the super-soft processes,observed experimentally in recent years.     

Observations and modeling of deterministic properties of human heart rate variability

Simple models show that in Type-I intermittency a characteristic U-shaped probability distribution is obtained for the laminar phase length. The laminar phase length distribution characteristic for Type-I intermittency may be obtained in human heart rate variability data for some cases of pathology. The heart and its regulatory systems are presumed to be both noisy and non-stationary. Although the effect of additive noise on the laminar phase distribution in Type-I intermittency is well-known, the effect of neither multiplicative noise nor non-stationarity have been studied. We first discuss the properties of two classes of models of Type-I intermittency: (a) the control parameter of the logistic map is changed dichotomously from a value within the intermittency range to just below the bifurcation point and back; (b) the control parameter is changed randomly within the same parameter range as in the model class (a). We show that the properties of both models are different from those obtained for Type-I intermittency in the presence of additive noise. The two models help to explain some of the features seen in the intermittency in human heart rate variability.     

Intermittency and jets

We show that intermittency, i.e. unlimited growth of multiplicity fluctuations with increasing resolution, is obtained in hadron cascade models with scale invariant branching structure. Strong effects are expected if in a multiparticle event not only the rapidity but simultaneously the azimuthal angle around the beam axis is analysed. The occurrence of narrow jets (“pencil jets”) is expected. The relevance of this type of study for models of hadronization is pointed out.     

Circuit implementation and multiform intermittency in ahyper-chaotic model extended from Lorenz system

<正>This paper presents a non-autonomous hyper-chaotic system,which is formed by adding a periodic driving signal to a four-dimensional chaotic model extended from the Lorenz system.The resulting non-autonomous hyper-chaotic system can display any dynamic behaviour among the periodic orbits,intermittency,chaos and hyper-chaos by controlling the frequency of the periodic signal.The phenomenon has been well demonstrated by numerical simulations,bifurcation analysis and electronic circuit realization.Moreover,the system is concrete evidence for the presence of Pomeau-Manneville Type-Ⅰintermittency and crisis-induced intermittency.The emergence of a different type of intermittency is similarly subjected to the frequency of periodic forcing.By statistical analysis,power scaling laws consisting in different intermittency are obtained for the lifetime in the laminar state between burst states.     

一个光学系统展示的V型阵发现象

本文报道基于一个光学系统的延时微分方程和方程的Poincaré映象计算得到的V型阵发及其主要标度规律,为我国科学工作者提出的阵发新型提供一个新的证据.     

The complete set of Hamiltonian intermittency scaling behaviors

Renormalization group equations describing the phenomenon of intermittency in Hamiltonian systems are presented. All solutions satisfying certain physical constraints are obtained; they are the complete set of simple singularities. Further considerations lead to precise predictions for scaling behavior at the onset of intermittency.     

Ising intermittency

Recent development of intermittency in the Ising model is reviewed. By means of various realization, the classical spin model is adopted to study the particle number fluctuations and the intermittent behavior. The analytical expressions in one dimension are obtained, both for the models with and without an external field. The onset of intermittency in the Ising model is more likely a characteristic of decoupling into one-dimensional subsystems. Received: 16 August 1996 / Revised version: 10 February 1998 / Published online: 24 March 1998     

Correlation between fluorescence intermittency and spectral diffusion in single semiconductor quantum dots

We find a correlation between the dynamics of fluorescence intermittency and spectral diffusion in the spectroscopy of single CdSe nanocrystal quantum dots (QD). A statistical analysis of the data suggests two populations of blinking events: blinking followed by large spectral diffusion shifts and blinking with small or no spectral shifts. Although unexpected from earlier studies, the correlation between blinking and spectral shifting is consistent with a model of QD ionization as the mechanism for the blinking event, followed by a redistribution of local electric fields that results in spectral shifting.     

Generation of on-off intermittency based on RSssler chaotic system

In this paper, one-state on-off intermittency and two-state on-off intermittency are generated in two five- dimensional continuum systems respectively. In each system, a two-dimensional subsystem is driven by the Rossler chaotic system. The parameter conditions under which the on-off intermittency occurs are discussed in detail. The statistical property of the intermittency is investigated. It is shown that the distribution of the laminar phase duration time follows a power law with an exponent of -3/2, which is a signature of on-off intermittency. Moreover, the phenomenon of intermingled basins is observed when attractors in the two symmetric invariant subspaces are stable. We provide an effective way to generate on-off intermittency based on a chaotic system, which is important for application and theoretical study.