共查询到19条相似文献,搜索用时 93 毫秒
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以蒙特卡罗模拟方法对自对耦分布二维随机链q态Potts模型的短时临界行为进行了数值研究.利用初始非平衡演化阶段存在的普适幂指数和有限体积标度行为,数值模拟了在不同形式随机分布时q=3和q=8态Potts模型磁临界指数η和动力学临界指数z.计算结果发现η不依赖于自对偶无序分布的具体形式, 从而以数值方法给出了一个关于淬火掺杂自旋系统的临界普适行为的验证.
关键词:
随机链Potts模型
动力学蒙特卡罗模拟
临界普适性 相似文献
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丝阵负载内爆动力学行为基本可以分为以下四个过程:1)丝的烧蚀;2)壳层的形成;3)内爆;4)滞止.利用所研制的可见光分幅相机和X射线分幅相机在"强光一号"加速器上对多种型号的丝阵负载Z箍缩内爆动力学行为进行了实验研究,获得了从早期单丝烧蚀到等离子体柱崩毁全过程图像,并对实验结果进行了分析,主要研究成果如下:1)发现存在较长时间的丝烧蚀过程,且单丝烧蚀在轴向上并不均匀;实验得到的内爆轨迹与唯像模型计算结果较为一致.2)不论早期的可见光图像还是中后期的软X射线图像都存在明显的阴极发射,内爆后期在阴极附近存在明
关键词:
丝阵
内爆动力学
Z箍缩
脉冲功率技术 相似文献
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We investigate the short-time critical dynamics of the Baxter-Wu (BW) and n=3 Turban (3TU) models to estimate their global persistence exponent θg. We conclude that this new dynamical exponent can be useful in detecting differences between the critical behavior of these models which are very difficult to obtain in usual simulations. In addition, we estimate again the dynamical exponents of the four-state Potts (FSP) model in order to compare them with results previously obtained for the BW and 3TU models and to decide between two sets of estimates presented in the current literature. We also revisit the short-time dynamics of the 3TU model in order to check if, as already found for the FSP model, the anomalous dimension of the initial magnetization x0 could be equal to zero. 相似文献
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Using Monte Carlo methods, the short-time dynamic scaling behaviour of two-dimensional critical XY systems is investigated. Our results for the XY model show that there exists universal scaling behaviour already in the short-time regime, but the values of the dynamic exponent z differ for different initial conditions. For the fully frustrated XY model, power law scaling behaviour is also observed in the short-time regime. However, a violation of the standard scaling relation between the exponents is detected. 相似文献
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We present our Monte Carlo results of the random-bond Potts ferromagnet with the Olson-Young self-dual distribution of quenched disorders in two dimensions. By exploring the short-time scaling dynamics, we find the universal power-law critical behavior of the magnetization and Binder cumulant at the critical point, and thus obtain estimates of the dynamic exponent z and magnetic exponent η, as well as the exponent θ. Our special attention is paid to the dynamic process for the q = 8 Potts model. 相似文献
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Spontaneous-search method and short-time dynamics: applications to the
Domany-Kinzel cellular automaton 总被引:1,自引:0,他引:1
S. D. da Cunha U. L. Fulco L. R. da Silva F. D. Nobre 《The European Physical Journal B - Condensed Matter and Complex Systems》2008,63(1):93-100
The one-dimensional Domany-Kinzel cellular automaton is investigated by two
numerical approaches: (i) the spontaneous-search method, which is a method
appropriated for a search of criticality; (ii) short-time dynamics. Both
critical frontiers of the system are investigated, namely, the one
separating the frozen and active phases, as well as the critical line
determined by damage spreading between two cellular automata, that splits
the active phase into the nonchaotic and chaotic phases.
The efficiency of the spontaneous-search method is established herein
through a precise estimate of both critical frontiers, and in addition to
that, it is shown that this method may also be used in the determination
of the critical exponent ν⊥. Using the critical frontiers
obtained, other exponents are estimated through short-time dynamics. It is
verified that the critical exponents of both critical frontiers fall in the
universality class of directed percolation. 相似文献
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The critical relaxation from the low-temperature ordered state of the three-dimensional Ising model with competing interactions on a simple cubic lattice has been studied for the first time using the short-time dynamics method. Competition between exchange interactions is due to the ferromagnetic interaction between the nearest neighbors and the antiferromagnetic interaction between the next nearest neighbors. Particles containing 262144 spins with periodic boundary conditions have been studied. Calculations have been performed by the standard Metropolis Monte Carlo algorithm. The static critical exponents of the magnetization and correlation radius have been calculated. The dynamic critical exponent of the model under study has been calculated for the first time. 相似文献
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It is shown that in the case of human heart rate, the scaling behavior of the correlation sum (calculated by the Grassberger-Procaccia algorithm) is a result of the interplay of various factors: finite resolution of the apparatus (finite-size effects), a wide dynamic range of mean heart rate, the amplitude of short-time variability being a decreasing function of the mean heart rate. This is done via constructing a simple model of heart rhythm: a signal with functionally modulated Gaussian noise. This model reproduces the scaling behavior of the correlation sum of real medical data. The value of the scaling exponent depends on all the above-mentioned factors, and is a certain measure of short-time variability of the signal. 相似文献
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A. K. Murtazaev V. A. Mutailamov 《Journal of Experimental and Theoretical Physics》2013,116(4):604-608
Critical relaxation from a low-temperature fully ordered state of Fe2/V13 iron-vanadium magnetic superlattice models has been studied using the method of short-time dynamics. Systems with three variants of the ratio R of inter-to intralayer exchange coupling have been considered. Particles with N = 262144 spins have been simulated with periodic boundary conditions. Calculations have been performed using the standard Metropolis algorithm of the Monte Carlo method. The static critical exponents of magnetization and correlation radius, as well as the dynamic critical exponent, have been calculated for three R values. It is established that a small decrease in the exchange ratio (from R = 1.0 to 0.8) does not significantly influence the character of the short-time dynamics in the models studied. A further significant decrease in this ratio (to R = 0.01), for which a transition from three-dimensional to quasi-two-dimensional magnetism is possible, leads to significant changes in the dynamic behavior of iron-vanadium magnetic superlattice models. 相似文献