387 research outputs found
On Mechanics of Light Propagation in Free Space with Final Temperature
Features of electromagnetic waves propagation of light range are considered in free space with final temperature 2.725K. The presence in space of temperature (and final density) allows justification to introduce the longitudinal component of electromagnetic field. A modified theory of electromagnetic waves propagation in free space is offered. Exact solutions of the nonlinear equations system in the presence of electric and gasdynamic interaction are obtained. Some of demonstrated exact solutions have a nature of continues and decretive spectrum
Spin current in (110)-oriented GaAs quantum wells
We consider a possibility of generation of the stationary spin current in (110) –
oriented GaAs-basedsymmetric quantum well due to the nonlinear response to externalperiodic
electric field. The model includes the Dresselhaus spin-orbit interaction and
the random Rashbaspin-orbit coupling.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/2055
Synthesis of Stable Aqueous Ceria Sols and Study of Their Toxicity
Cerium dioxide is a unique material which is promising for biomedical applications. The properties of
ceria are definitely determined by synthesis procedure and further treatment conditions. The vast majority
of currently existing methods of synthesis lead to formation of CeO2 in the form of nanopowders, but in
some cases (e.g., in biological applications), such powders can not be used because they do not quite satisfy
practical requirements. So, in this work we succeed in synthesis of ceria-stable sols with controlled small
particle size (2-4 nm) using an inexpensive and facile method and investigated the effect of changing the
concentrations and the molar ratio of initial reagents on particle size of CeO2. In this paper we also propose
a method of evaluation of toxicity of ceria sols using bioluminescent microorganism Vibrio fischeri. According
to the results obtained CeO2 sols of different concentrations (6.3*10-4 – 0,02M) are not toxic to Vibrio
fischeri.
When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3495
New exact solutions in standard inflationary models
The exact solutions in the standard inflationary model based on the
self-interacting scalar field minimally coupled to gravity are considered. The
shape's freedom of the self-interacting potential is postulated to
obtain a new set of the exact solutions in the framework of
Friedmann-Robertson-Walker Universes. The general solution was found in the
case of power law inflation. We obtained new solutions and compared them with
obtained ones earlir for the exponential type inflation.Comment: 12 pages, Latex, to appear in: Phys.Lett.
First-principles study of electron transport through cages
Electron transport properties of C molecules suspended between gold
electrodes are investigated using first-principles calculations. Our study
reveals that the conductances are quite sensitive to the number of C
molecules between electrodes: the conductances of C monomers are near 1
G, while those of dimers are markedly smaller, since incident electrons
easily pass the C molecules and are predominantly scattered at the
C-C junctions. Moreover, we find both channel currents locally
circulating the outermost carbon atoms.Comment: 8 pages and 3 figure
Formalism of collective electron excitations in fullerenes
We present a detailed formalism for the description of collective electron
excitations in fullerenes in the process of the electron inelastic scattering.
Considering the system as a spherical shell of a finite width, we show that the
differential cross section is defined by three plasmon excitations, namely two
coupled modes of the surface plasmon and the volume plasmon. The interplay of
the three plasmons appears due to the electron diffraction of the fullerene
shell. Plasmon modes of different angular momenta provide dominating
contributions to the differential cross section depending on the transferred
momentum.Comment: 11 pages, 2 figures; submitted to the special issue "Atomic Cluster
Collisions: Structure and Dynamics from the Nuclear to the Biological Scale"
of Eur. Phys. J.
Multifractal stationary random measures and multifractal random walks with log-infinitely divisible scaling laws
We define a large class of continuous time multifractal random measures and
processes with arbitrary log-infinitely divisible exact or asymptotic scaling
law. These processes generalize within a unified framework both the recently
defined log-normal Multifractal Random Walk (MRW) [Bacry-Delour-Muzy] and the
log-Poisson "product of cynlindrical pulses" [Barral-Mandelbrot]. Our
construction is based on some ``continuous stochastic multiplication'' from
coarse to fine scales that can be seen as a continuous interpolation of
discrete multiplicative cascades. We prove the stochastic convergence of the
defined processes and study their main statistical properties. The question of
genericity (universality) of limit multifractal processes is addressed within
this new framework. We finally provide some methods for numerical simulations
and discuss some specific examples.Comment: 24 pages, 4 figure
ϒ production in p–Pb collisions at √sNN=8.16 TeV
ϒ production in p–Pb interactions is studied at the centre-of-mass energy per nucleon–nucleon collision √sNN = 8.16 TeV with the ALICE detector at the CERN LHC. The measurement is performed reconstructing bottomonium resonances via their dimuon decay channel, in the centre-of-mass rapidity intervals 2.03 < ycms < 3.53 and −4.46 < ycms < −2.96, down to zero transverse momentum. In this work, results on the ϒ(1S) production cross section as a function of rapidity and transverse momentum are presented. The corresponding nuclear modification factor shows a suppression of the ϒ(1S) yields with respect to pp collisions, both at forward and backward rapidity. This suppression is stronger in the low transverse momentum region and shows no significant dependence on the centrality of the interactions. Furthermore, the ϒ(2S) nuclear modification factor is evaluated, suggesting a suppression similar to that of the ϒ(1S). A first measurement of the ϒ(3S) has also been performed. Finally, results are compared with previous ALICE measurements in p–Pb collisions at √sNN = 5.02 TeV and with theoretical calculations.publishedVersio
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