Long cycles in abc-permutations

An abc-permutation is a permutation σ _abc ∈S _n obtained by exchanging an initial block of length a and a final block of length c of {1,…,n}, where n=a+b+c. In this note we compute the limit of the probability that a random abc-permutation is a long cycle. This resolves Arnold’s open problem (Arnold in Arnold’s problems, 2004, p. 144).      

A short proof of rigidity of convex polytopes

We present a much simplified proof of Dehn’s theorem on the infinitesimal rigidity of convex polytopes. Our approach is based on the ideas of Trushkina [1] and Schramm [2].     

Energy dependence of directed flow over a wide range of pseudorapidity in Au + Au collisions at the BNL Relativistic Heavy Ion Collider

We report on measurements of directed flow as a function of pseudorapidity in Au + Au collisions at energies of square root of SNN = 19.6, 62.4, 130 and 200 GeV as measured by the PHOBOS detector at the BNL Relativistic Heavy Ion Collider. These results are particularly valuable because of the extensive, continuous pseudorapidity coverage of the PHOBOS detector. There is no significant indication of structure near midrapidity and the data surprisingly exhibit extended longitudinal scaling similar to that seen for elliptic flow and charged particle pseudorapidity density.     

金融市场中经纪人相互竞争和适应性行为的物理模型

金融物理中的争当少数者博奕模型,是一个用来模拟金融市场动力学行为的最简单的模型,可以尝试利用它来对实际金融市场中许多现象提供物理的理解.文章介绍了关于金融物理的争当少数者博奕模型的一些主要研究结果和若干最新的发展方向.     

Using a hot‐wire anemometer for measurement of characteristics of a random acoustic field in compressible flows

The problem of interpretation of hotwire measurements of acoustic fields in compressible flows is considered. Relations between massflow and totaltemperature fluctuations registered by a hotwire anemometer and pressure and velocity fluctuations are found. The relations obtained are applicable in the general case for measurement of resultant acoustic fluctuations at some point of the flow, which are generated by arbitrary distributed sources of sound with priorunknown properties.     

Theoretical Investigation of Normal to Strong Hydrogen Bonds

We review our theoretical work done on a variety of different chemical systems, which show different H-bonding characteristics. The systems include water clusters, its interactions with polar molecules and π-systems, organic nanotubes, enzymes, and ionophores/receptors. Special features of normal, short, short strong, and π-type H-bonding interactions in these systems are discussed in terms of structures, interaction energies, and spectra.     

An experimental study on high-purity uranium refining by passing in succession through pulsed extraction,washing, and stripping columns

Nuclear-purity uranium was refined by passing a solution of uranyl nitrate in 3–5 M HNO₃ in succession through pulsed extraction, washing, and stripping columns for feeding into the U(III)–U(IV) chemical exchange system for uranium isotope separation. The extractant (tri-n-butyl phosphate, TBP), the diluent (kerosene), nitric acid, ammonium carbonate, sodium nitrate, and water were preliminarily refined to chemical purity. The diameter and height of pulsed columns for uranium purification was 25 and 1500 mm, respectively, and the pulse frequency was 1 s^–1. The content of transition metals (Fe, Co, Ni, Cu, Ag) and Pb, which can catalyze the U(III) oxidation in acidic aqueous solutions, was reduced to the level lower than 1 ppm (10^–4%). The total purification factor was higher than 103. The purification required 3–4 theoretical plates with HETP of the columns of 35–40 cm.     

Dynamics of Optical Pulse Propagation in the Ribbon Formed by Graphene and Boron Nitride Layers of Finite Width

The propagation of an ultrashort optical pulse in the multilayered structure formed by alternating graphene and boron nitride layers is considered. Conduction electrons of this system at low temperatures are described by the effective long-wavelength Hamiltonian, and the electromagnetic field is considered based on the classical Maxwell equations. Dependence of the evolution on the ultrashort pulse amplitude and nanoribbon layer width is established.