181 research outputs found
Roton dipole moment
The roton excitation in the superfluid He-4 does not possess a stationary
dipole moment. However, a roton has an instantaneous dipole moment, such that
at any given moment one can find it in the state either with positive or with
negative dipole moment projection on its momentum direction. The instantaneous
value of electric dipole moment of roton excitation is evaluated. The result is
in reasonable agreement with recent experimental observation of the splitting
of microwave resonance absorption line at roton frequency under external
electric field.Comment: 5 page
Intermittency as a universal characteristic of the complete chromosome DNA sequences of eukaryotes: From protozoa to human genomes
Large-scale dynamical properties of complete chromosome DNA sequences of
eukaryotes are considered. By the proposed deterministic models with
intermittency and symbolic dynamics we describe a wide spectrum of large-scale
patterns inherent in these sequences, such as segmental duplications, tandem
repeats, and other complex sequence structures. It is shown that the recently
discovered gene number balance on the strands is not of random nature, and a
complete chromosome DNA sequence exhibits the properties of deterministic
chaos.Comment: 4 pages, 5 figure
Some mechanisms of "spontaneous" polarization of superfluid He-4
Previously, a quantum "tidal" mechanism of polarization of the atoms of He-II
was proposed, according to which, as a result of interatomic interaction, each
atom of He-II acquires small fluctuating dipole and multipole moments, oriented
chaotically on the average. In this work, we show that, in the presence of a
temperature or density gradient in He-II, the originally chaotically oriented
tidal dipole moments of the atoms become partially ordered, which results in
volume polarization of He-II. It is found that the gravitational field of the
Earth induces electric induction U =10(-7)V in He-II (for vessel dimensions of
the order of 10 cm). We study also the connection of polarization and
acceleration, and discuss a possible nature of the electric signal dU = kdT/2e
observed by A.S. Rybalko in experiments with second sound.Comment: 13 pages; the calculation is extended and refined; v4: reconstructio
On the electric activity of superfluid systems
The Keldysh's theory of superfluidity of rarefied electron-hole gas is
generalized to a case of possible pair polarizability. It was shown that
inhomogeneity of the system leads to dipole moment which is proportional to the
density gradient. The dipole moment appears also near boundaries of the system.
It was determined that quantized vortices in a magnetic field carry a real
electric charge. In He II at H=10 T and helium rotation velocity
s the charge density is about cm, where is the
electron charge.Comment: 5 pages V. 2: replaced incorrect g valu
Theory of a Narrow roton Absorption Line in the Spectrum of a Disk-Shaped SHF Resonator
We calculate the probability of the birth of a circular phonon (c-phonon) in
He II by a c-photon of the resonator. It is shown that this probability has
sharp maxima at frequencies, where the effective group velocity of the c-phonon
is equal to zero; the density of states of c-phonons strongly grows at such
frequencies. For He II, these frequencies correspond to a roton and a maxon.
From the probability of the c-roton birth, we calculate the roto line width
which is found to approximately agree with the experimental one. We conclude
that the roton line observed in the super-high-frequency (SHF) absorption
spectrum of helium is related to the birth of c-rotons. A possible
interpretation of the Stark effect observed for the roton line is also
proposed.Comment: 13 pages, 1 figure, v2: journal variant, several minor correction
Using of High-Strength Protective Coatings, Reducing the Risk of Initiation and Development of SCC Defects
The article is devoted to the application of new methods of protection of trunk pipelines with defects of stress corrosion cracking. New anti-corrosion coatings will significantly reduce the stress level in the pipeline being repaired, preventing the development of SCC defects. © 2022 American Institute of Physics Inc.. All rights reserved.Ural Branch, Russian Academy of Sciences, UB RASThe work was performed within the state assignment on the subjects Diagnostics (No. AAAA-A18-118020690196-3) and supported by a UB RAS Program project
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