共查询到20条相似文献,搜索用时 15 毫秒
1.
We study the relaxation dynamics of a semiflexible chain by introducing a time-dependent tension. The chain has one of its ends attached to a large bead, and the other end is fixed. We focus on the initial relaxation of the chain that is initially strongly stretched. Using a tension that is self-consistently determined, we obtain the evolution of the end-to-end distance with no free parameters. Our results are in good agreement with single molecule experiments on double stranded DNA. 相似文献
2.
《Physics letters. A》2019,383(20):2370-2375
We consider a bosonic Josephson junction in the Bose-Hubbard two-mode approximation where some of the parameters are corrupted by physically meaningful noise processes and study the corresponding relaxation dynamics towards its equilibrium state. We show with numerical simulations that this model can essentially capture all the important features observed in a recent experiment regarding the relaxation dynamics in one-dimensional bosonic Josephson junctions, namely the damped oscillations of the population imbalance and the relative phase, as well as the large final coherence factor. We expect that this work will further motivate research about the origin of relaxation mechanism in these systems. 相似文献
3.
4.
5.
Shahar Hod 《Physics letters. A》2010,374(29):2901-2903
We study analytically the relaxation dynamics of charged test fields left outside a newly born charged black hole. In particular, we obtain a simple analytic expression for the fundamental quasinormal resonances of near-extremal Reissner-Nordström black holes. The formula is expressed in terms of the black-hole physical parameters: , where TBH and Φ are the temperature and electric potential of the black hole, and q is the charge of the field. 相似文献
6.
7.
We measure the geometry of a crumpled sheet of paper with laser-aided topography and discuss its statistical properties. The curvature of an elastoplastic fold scales linearly with applied force. The curvature distribution follows an exponential form with regions of high curvature localized along ridges. The measured ridge length distribution is consistent with a hierarchical model for ridge breaking during crumpling. A large fraction of the ridges are observed to terminate without bifurcating, and the ridge network connectedness is not as complete as anticipated. The self-affinity of the surface is characterized by a Hurst exponent of 0.71+/-0.01 in contrast with previous results. 相似文献
8.
A statistical study of crumpled paper is allowed by a minimal 1D model: a self-avoiding line bent at sharp angles--in which the elastic energy resides--put in a confining potential. Many independent equilibrium configurations are generated numerically and their properties are investigated. At small confinement, the distribution of segment lengths is log-normal in agreement with previous predictions and experiments. At high confinement, the system approaches a jammed state with a critical behavior, whereas the length distribution follows a gamma law in which the parameter is predicted as a function of the number of layers in the system. 相似文献
9.
We present molecular dynamics simulations of liquid water at normal and supercooled conditions. Autocorrelation functions (ACFs) of several structural quantities and their fourier transforms are obtained and analysed. Structural correlations and relaxation times increase linearly with degree of supercooling. Power spectra of ACFs show increase in librational motion of liquid water with cooling. These modes intensify with supercooling because of structuring and ordering of water molecules. Overall, liquid water structure is homogenous over the temperatures and pressures studied and undergoes fluctuation–dissipation in its local-density variations [English and Tse, Phys. Rev. Lett. 106, 037801 (2011)]. 相似文献
10.
We find that in two dimensions wires can crumple into different morphologies and present the associated morphological phase diagram. Our results are based on experiments with different metallic wires and confirmed by numerical simulations using a discrete element model. We show that during crumpling, the number of loops increases according to a power law with different exponents in each morphology. Furthermore, we observe a power law divergence of the structure's bulk stiffness similar to what is observed in forced crumpling of membranes. 相似文献
11.
A. A. Karabutov V. A. Larichev G. A. Maksimov I. M. Pelivanov N. B. Podymova 《Acoustical Physics》2006,52(5):582-588
The first experimental observation of the propagation dynamics of a short broadband acoustic pulse in a resonance medium with gas bubbles is carried out. The probing pulse is generated using the optoacoustic effect. It is shown that the theory of short pulse propagation in media with generalized resonance relaxation adequately and accurately describes the dynamics of short pulse dispersion. A possibility to determine the relaxation and resonance parameters of media by the pulsed testing technique is demonstrated. 相似文献
12.
The relaxation of holes inp-Ge excited by CO2 laser radiation is analyzed in a detailed cascade model. The scattering times are taken in part from theory and from recent saturation-spectroscopic measurements. From this model we calculate the photoconductive response quantitatively. Experimentally we observe the conductivity change induced by single ns CO2 laser pulses and find good agreement with the predictions. 相似文献
13.
Ovadyahu Z 《Physical review letters》2007,99(22):226603
It is experimentally shown that, depending on the carrier concentration of the system n, the dynamics of electron glasses either slows down with increasing temperature or it is independent of it. This also correlates with the dependence of a typical relaxation time (or "viscosity") on n. These linked features are argued to be consistent with a model for dissipative tunneling. The slow relaxation of the electron glass may emerge then as a manifestation of friction in a many-body quantum system. Our considerations may also explain why strongly localized granular metals are likely to show electron-glass effects while semiconductors are not. 相似文献
14.
15.
Duplantier B 《Physical review letters》1987,58(26):2733-2737
16.
We investigate the dynamics of cell signaling using an experimentally based Boolean model of the human fibroblast signal transduction network. We determine via systematic numerical simulations the relaxation dynamics of the network in response to a constant set of inputs, both in the absence and in the presence of environmental fluctuations. We then study the network's response to periodically modulated signals, uncovering different types of behaviors for different pairs of driven input and output nodes. The phenomena observed include low-pass, high-pass, and band-pass filtering of the input modulations, among other nontrivial responses, at frequencies around the relaxation frequency of the network. The results reveal that the dynamic response to the external modulation of biologically realistic signaling networks is versatile and robust to noise. 相似文献
17.
The quantum trajectory method has been applied to study the influence of noise on the level populations of a cubit in separate
realizations of the experiment and to follow the transition to the averaged dynamics obtained by multiple measurements of
the cubit state. As an example of applying the developed method, the influence of noise on the interference pattern appearing
in amplitude spectroscopy due to the Landau-Zener transitions in an alternating field has been analyzed. The influence of
the number of repeated measurements and fluctuations in the phase of the exciting pulse during formation of the response of
a cubit to the external field has been studied, which made it possible to interpret recent experiments from the viewpoint
of single realizations and averaged dynamics. 相似文献
18.
We show how the quantum analog of the Fokker-Planck equation for describing
Brownian motion can be obtained as the diffusive limit of the quantum linear
Boltzmann equation. The latter describes the quantum dynamics of a tracer
particle in a dilute, ideal gas by means of a translation-covariant master
equation. We discuss the type of approximations required to obtain the
generalized form of the Caldeira-Leggett master equation, along with their
physical justification. Microscopic expressions for the diffusion and
relaxation coefficients are obtained by analyzing the limiting form of the
equation in both the Schr?dinger and the Heisenberg picture. 相似文献
19.
20.