辩证统一视野下党的思想路线的精髓

主观与客观相符合、思想与实际相符合是党的思想路线的矛盾(对立统一)规律。党的思想路线的矛盾的普遍性与特殊性的辩证统一关系问题是一个重大的马克思主义理论与实践问题。解放思想与实事求是相互间的关系是党的思想路线的矛盾的特殊性与普遍性的辩证统一。实事求是是党的思想路线的矛盾的普遍性。解放思想、实事求是、与时俱进、科学发展观构成党的思想路线的矛盾的普遍性与特殊性的辩证统一的主要内容和历史发展。党的思想路线的矛盾的普遍性与特殊性的辩证统一是党的思想路线的精髓。     

Toward a Universal Behavior of Linear Athermal Model Chains in the Limit of Infinite Chain‐length

Athermal chains of various stiffness embedded in several types of lattices were analyzed with respect to their pair distribution function G(R). Extrapolation to infinite chain‐length on a reduced distance scale made all the G(R) data coincide within extremely narrow limits, thus suggesting the existence of a universal pair distribution function for polymers in good solvents in the long‐chain limit. The ratio –ln(G(R))/Z(R) with Z(R) being the reduced distribution of overlaps is also universal in type and varies only little with distance R. Further, a likewise universal function could be established that allows the construction of Z(R) from the Flory–Krigbaum expression taking into account not only the deviations from Gaussian behavior but also the effect of intramolecular repulsion present in athermal chains.

     

Chaos in modulated logistic systems

This paper is a review of the work done on the dynamics of modulated logistic systems. Three different problems are treated, viz, the modulated logistic map, the parametrically perturbed logistic map and the combination map obtained by combining two maps of the quadratic family. Many of the interesting features displayed by these systems are discussed.     

斯格明子相关的螺旋磁有序体系的临界行为

介绍了与斯格明子相关的螺旋磁有序体系的临界行为.首先阐述了连续相变中的临界现象、临界指数、标度律、普适性等概念;随后介绍了磁相变体系中几种临界指数的获得方法,包括直流磁性迭代法、磁熵变法;进而,分析了几类与斯格明子相关的螺旋磁有序体系的临界行为.MnSi是典型的斯格明子材料,临界指数显示其磁性行为符合三重临界行为.MnSi的临界行为揭示:外磁场可以抑制这一体系在零场下的一级相变,使其转变为二级相变,从而在螺旋磁有序、锥形磁有序、顺磁相的三相交汇点形成三重临界点.斯格明子体系FeGe和Cu_2OSeO_3的临界行为符合三维海森伯相互作用,表明它们的磁性行为主要是由近邻的各向同性的自旋耦合作用所决定;而Fe_(1-x)Co_xSi和新发现的斯格明子体系Fe_(1.5-x)Co_xRh_(0.5)MoN的临界行为显示Co掺杂可以有效地调制其中的磁性耦合.对螺旋磁有序体系的临界行为研究表明,尽管这些体系都表现出类似的斯格明子态,但是它们的磁性耦合机制却大不相同,并且其耦合机制可以受到外界手段的调制.最后,根据普适性原理和标度方程,阐述了一种构建磁场诱导相变体系在临界温度附近H-T相图的方法.     

Optically induced phase transition of excitons in coupled quantum dots

The weak classical light excitations in many semiconductor quantum dots have been chosen as important solid- state quantum systems for processing quantum information and implementing quantum computing. For strong classical light we predict theoretically a novel phase transition as a function of magnitude of this classical light from the deformed to the normal phases in resonance ease, and the essential features of criticality such as the scaling behaviour, critical exponent and universality are also present in this paper.     

Noisy one-dimensional maps near a crisis. I. Weak Gaussian white and colored noise

We study one-dimensional single-humped maps near the boundary crisis at fully developed chaos in the presence of additive weak Gaussian white noise. By means of a new perturbation-like method the quasi-invariant density is calculated from the invariant density at the crisis in the absence of noise. In the precritical regime, where the deterministic map may show periodic windows, a necessary and sufficient condition for the validity of this method is derived. From the quasi-invariant density we determine the escape rate, which has the form of a scaling law and compares excellently with results from numerical simulations. We find that deterministic transient chaos is stabilized by weak noise whenever the maximum of the map is of orderz>1. Finally, we extend our method to more general maps near a boundary crisis and to multiplicative as well as colored weak Gaussian noise. Within this extended class of noises and for single-humped maps with any fixed orderz>0 of the maximum, in the scaling law for the escape rate both the critical exponents and the scaling function are universal.     

Fractal dimension and grand Universality of critical phenomena

Conformation of branched random fractals formed in equilibrium processes is discussed using a Flory-type theory. Within this approach we find only three distinct types or classes of random fractals. We call these theextended, thecompensated, and thecollapsed states. In particular, the critical clusters in thermal phase transitions are found to be of the compensated type and have approximately the same value of the fractal dimension. The Flory theory predicts the upper critical dimension for these clusters to be 6 instead of 4. This result and the apparent grand universality of the fractal geometry of the clusters in critical phenomena are discussed.     

Computer simulation of irreversible kinetic gelation: Crossover between random and kinetic growth,radical conservation,poisons, and chain-preferred reactions

A Monte-Carlo study is presented for irreversible kinetic gelation in binary polymers in three dimensions. Using a growth scheme where attempts are made to form bonds with the help of radicals with probabilityk/(1+k) and without the help of radicals with probability 1/(1+k), wherek=0,1,2, ..., , we have studied the crossover from one universality class of critical phenomena in kinetic gelation to another universality class of random percolation. In the radical assisted gelation, several features are incorporated to make the model more realistic, for example, the conservation of the number of radicals during the growth (more suited for living anionic polymerization), the introduction of poisons and chain-preferring reactions are considered. Conserving the radicals delays gelation as well as trapping. The trapping can also be delayed by increasing the functionality of the monomers. The effect of the poison is rather severe; even a small concentration of poison (c _p >2%) terminates the reaction well before the gel point in a mixture of binary and ternary monomers, and it seems to affect the critical phenomena in the sol-gel phase transitions. In our growth mechanism, where reactions prefer to growL length steps each in a random direction, the critical phenomena remain unaffected by the length scale, but the flexibility of varying the chain stepL allows us to study the changeover between the phase transition in different gel structures.     

Recurrence of Kolmogorov-Arnold-Moser tori in nonanalytic twist maps

We study a class of twist maps where the functiong()=(1–|2| ^z–1) is nonanalytic (C ¹) and endowed with a varying degree of inflectionz. Whenz>3, reappearance of a KAM torus after its breakup has been observed. We introduce an inverse residue criterion to determine the reappearance point. Scaling behavior at the transition points is also studied. For 2z<3 the scaling exponents are found to vary withz, whereas forz3 they are independent ofz. In this sensez=3 plays a role quite similar to that of the upper critical dimension in phase transitions.     

The dimension spectrum of some dynamical systems

We analyze the dimension spectrum previously introduced and measured experimentally by Jensen, Kadanoff, and Libchaber. Using large-deviation theory, we prove, for some invariant measures of expanding Markov maps, that the Hausdorff dimensionf() of the set on which the measure has a singularity is a well-defined, concave, and regular function. In particular, we show that this is the case for the accumulation of period doubling and critical mappings of the circle with golden rotation number. We also show in these particular cases that the functionf is universal.