185 research outputs found
Localization-delocalization transition on a separatrix system of nonlinear Schrodinger equation with disorder
Localization-delocalization transition in a discrete Anderson nonlinear
Schr\"odinger equation with disorder is shown to be a critical phenomenon
similar to a percolation transition on a disordered lattice, with the
nonlinearity parameter thought as the control parameter. In vicinity of the
critical point the spreading of the wave field is subdiffusive in the limit
. The second moment grows with time as a powerlaw , with exactly 1/3. This critical spreading finds its
significance in some connection with the general problem of transport along
separatrices of dynamical systems with many degrees of freedom and is
mathematically related with a description in terms fractional derivative
equations. Above the delocalization point, with the criticality effects
stepping aside, we find that the transport is subdiffusive with
consistently with the results from previous investigations. A threshold for
unlimited spreading is calculated exactly by mapping the transport problem on a
Cayley tree.Comment: 6 pages, 1 figur
E-pile model of self-organized criticality
The concept of percolation is combined with a self-consistent treatment of
the interaction between the dynamics on a lattice and the external drive. Such
a treatment can provide a mechanism by which the system evolves to criticality
without fine tuning, thus offering a route to self-organized criticality (SOC)
which in many cases is more natural than the weak random drive combined with
boundary loss/dissipation as used in standard sand-pile formulations. We
introduce a new metaphor, the e-pile model, and a formalism for electric
conduction in random media to compute critical exponents for such a system.
Variations of the model apply to a number of other physical problems, such as
electric plasma discharges, dielectric relaxation, and the dynamics of the
Earth's magnetotail.Comment: 4 pages, 2 figure
Fracton pairing mechanism for "strange" superconductors: Self-assembling organic polymers and copper-oxide compounds
Self-assembling organic polymers and copper-oxide compounds are two classes
of "strange" superconductors, whose challenging behavior does not comply with
the traditional picture of Bardeen, Cooper, and Schrieffer (BCS)
superconductivity in regular crystals. In this paper, we propose a theoretical
model that accounts for the strange superconducting properties of either class
of the materials. These properties are considered as interconnected
manifestations of the same phenomenon: We argue that superconductivity occurs
in the both cases because the charge carriers (i.e., electrons or holes)
exchange {\it fracton excitations}, quantum oscillations of fractal lattices
that mimic the complex microscopic organization of the strange superconductors.
For the copper oxides, the superconducting transition temperature as
predicted by the fracton mechanism is of the order of K. We suggest
that the marginal ingredient of the high-temperature superconducting phase is
provided by fracton coupled holes that condensate in the conducting
copper-oxygen planes owing to the intrinsic field-effect-transistor
configuration of the cuprate compounds. For the gate-induced superconducting
phase in the electron-doped polymers, we simultaneously find a rather modest
transition temperature of K owing to the limitations imposed by
the electron tunneling processes on a fractal geometry. We speculate that
hole-type superconductivity observes larger onset temperatures when compared to
its electron-type counterpart. This promises an intriguing possibility of the
high-temperature superconducting states in hole-doped complex materials. A
specific prediction of the present study is universality of ac conduction for
.Comment: 12 pages (including separate abstract page), no figure
RESVERATROL IN KUBAN WINES
Purpose: The main purpose of viticulture is to improve the quality of the grapes, both to a greater extent for ampelotherapy and winemaking, and, to a lesser extent, to onotherapy.
Methodology: The article highlights the results of perennial (from 2014) studies of 18 promising technical grape varieties from different zones of the Krasnodar Territory: Anapo-Taman, Central, as well as Amur from the Black Sea zone of the Krasnodar Territory and two control Western European world-famous and most common varieties Merlot and Cabernet-Sauvignon in the same zones.
Result: The average values of resveratrol were found in wine materials from the varieties Vladimir and Dmitry (4.7 mg / dm3), Podlesny (3.9 mg / dm3), Saperavi Severny (3.5 mg / dm3), 40 let Octiabria (3.3 mg / dm3), Kurchansky and 40 let Pobedy (3.0 and 2.9 mg / dm3, respectively). On the other hand, as shown by the analysis of wine materials, the Antaris, Varyushkin, Mitsar and Plechistik varieties synthesize a lower content of resveratrol (1.0 and 0.9 mg / dm3, respectively).
Applications: This research can be used for the universities, teachers and education students.
Novelty/Originality: In this research, the model of resveratrol in Kuban wines is presented in a comprehensive and complete manner
Algorithmic statistics: forty years later
Algorithmic statistics has two different (and almost orthogonal) motivations.
From the philosophical point of view, it tries to formalize how the statistics
works and why some statistical models are better than others. After this notion
of a "good model" is introduced, a natural question arises: it is possible that
for some piece of data there is no good model? If yes, how often these bad
("non-stochastic") data appear "in real life"?
Another, more technical motivation comes from algorithmic information theory.
In this theory a notion of complexity of a finite object (=amount of
information in this object) is introduced; it assigns to every object some
number, called its algorithmic complexity (or Kolmogorov complexity).
Algorithmic statistic provides a more fine-grained classification: for each
finite object some curve is defined that characterizes its behavior. It turns
out that several different definitions give (approximately) the same curve.
In this survey we try to provide an exposition of the main results in the
field (including full proofs for the most important ones), as well as some
historical comments. We assume that the reader is familiar with the main
notions of algorithmic information (Kolmogorov complexity) theory.Comment: Missing proofs adde
Резервирование в тяговом приводе локомотива
The main purpose of the presented work is to study the possibility of using for rail transport (in particular, for development of promising structures and components of locomotive traction electric drive) of new technical solutions for transmission gears. A design development of gear drive is offered with high processability indices for manufacturing and operation. The possibility of implementation of layout diagram of traction drive with parallel power flows the basis of this gear drive is shown.Основной целью представленной работы является исследование возможности применения на железнодорожном транспорте (в частности, при разработке перспективных конструкций и элементов тягового электропривода локомотива) новых технических решений для передаточных механизмов. Предложена конструкторская разработка зубчатой передачи с высокими показателями технологичности при изготовлении и эксплуатации. Обоснована возможность реализации на базе этой зубчатой передачи компоновочной схемы тягового привода с параллельными потоками мощности
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