636 research outputs found
Strategic directions of transport and logistics to ensure the implementation of new industrialization processes
Ensuring the processes of industrialization of the modern economy requires the formation of an efficient transport and logistics infrastructure. The solution of this task is carried out using the tools of strategic management, in particular the formation of strategic goals. The article presents the strategic goals and the corresponding strategic measures in the field of ensuring the availability and quality of transport and logistics services in the field of freight traffic at the level of the needs of the development of the economy of the Sverdlovsk region. © Published under licence by IOP Publishing Ltd
Beyond Moore's technologies: operation principles of a superconductor alternative
The predictions of Moore's law are considered by experts to be valid until
2020 giving rise to "post-Moore's" technologies afterwards. Energy efficiency
is one of the major challenges in high-performance computing that should be
answered. Superconductor digital technology is a promising post-Moore's
alternative for the development of supercomputers. In this paper, we consider
operation principles of an energy-efficient superconductor logic and memory
circuits with a short retrospective review of their evolution. We analyze their
shortcomings in respect to computer circuits design. Possible ways of further
research are outlined.Comment: OPEN ACCES
Mathematical modeling of oscillatory processes in equal frequency antivibrating devices
Наведено результати математичного моделювання коливальних процесів при гармонійному збурюванні в системах, які містять віброізолюючі пристрої з механічним зворотним зв'язком. Показано, що нелінійні пружні характеристики таких пристроїв можуть визначати як близькі до гармонійного, так і негармонійні коливання і є дуже чутливими до зсуву центра коливань щодо положення пружної рівноваги системи.The results of mathematical modeling of oscillatory processes are given at harmonically indignation in systems containing antivibrating devices with a mechanical feedback. Is shown, that the nonlinear elastic characteristics of such devices can define as close to harmonically, and non harmonically to fluctuations and are very sensitive to displacement of the centre of fluctuations concerning a rule of elastic balance of system
Influence of the spin-dependent quasiparticle distribution on the Josephson current through a ferromagnetic weak link
The Josephson current flowing through weak links containing ferromagnetic
elements is studied theoretically under the condition that the quasiparticle
distribution over energy states in the interlayer is spin-dependent. It is
shown that the interplay between the spin-dependent quasiparticle distribution
and the triplet superconducting correlations induced by the proximity effect
between the superconducting leads and ferromagnetic elements of the interlayer,
leads to the appearence of an additional contribution to the Josephson current.
This additional contribution can be extracted from the full Josephson
current in experiment. The features of the additional supercurrent , which
are of main physical interest are the following: (i) We propose the
experimental setup, where the contributions given by the short-range (SRTC) and
long-range (LRTC) components of triplet superconducting correlations in the
interlayer can be measured separately. It can be realized on the basis of
S/N/F/N/S junction, where the interlayer is composed of two normal metal
regions with a spiral ferromagnet layer sandwiched between them. For the case
of tunnel junctions the measurement of in such a system can provide
direct information about the energy-resolved anomalous Green's function
components describing SRTC and LRTC. (ii) In some cases the exchange
field-suppressed supercurrent can be not only recovered but also enhanced with
respect to its value for non-magnetic junction with the same interface
resistances by the presence of spin-dependent quasiparticle distribution. This
effect is demonstrated for S/N/S junction with magnetic S/N interfaces. In
addition, it is also found that under the considered conditions the dependence
of the Josephson current on temperature can be nontrivial: at first the current
rises upon temperature increasing and only after that starts to decline.Comment: 19 pages, 9 figures, published version, presentation improve
Some results of cislunar plasma research
The main results of plasma cislunar investigations, carried out during Luna-19 and Luna-22 spacecraft flights by means of dual frequency dispersion interferrometry, are briefly outlined. It is shown that a thin layer of plasma, with a height of several tens of kilometers and a maximum concentration of the order 1,000 electrons/cu cm exists above the solar illuminated lunar surface. A physical model of the formation and existence of such a plasma in cislunar space is proposed, taking into account the influence of local magnetic areas on the moon
The nighttime ionosphere of Mars from Mars-4 and Mars-5 radio occultation dual-frequency measurements
Dual frequency radio sounding of the Martian nighttime ionosphere was carried out during the exits from behind the planet of the Mars-4 spacecraft on February 2, 1974 and the Mars-5 spacecraft on February 18, 1974. In these experiments, the spacecraft transmitter emitted two coherent monochromatic signals in decimeter and centimeter wavelength ranges. At the Earth receiving station, the reduced phase difference (or frequencies) of these signals was measured. The nighttime ionosphere of Mars measured in both cases had a peak electron density of approximately 5 X 1,000/cu cm at an altitude of 110 to 130 km. At the times of spacecraft exit, the solar zenith angles at the point of occultation were 127 deg and 106 deg, respectively. The height profiles of electron concentration were obtained assuming spherical symmetry of the Martian ionosphere
Experimental and theoretical analysis of the upper critical field in FSF trilayers
The upper critical magnetic field H_{c2} in thin-film FSF trilayer spin-valve
cores is studied experimentally and theoretically in geometries perpendicular
and parallel to the heterostructure surface. The series of samples with
variable thicknesses of the bottom and of the top Cu_{41}Ni_{59} F-layers are
prepared in a single run, utilizing a wedge deposition technique. The critical
field H_{c2} is measured in the temperature range K and for magnetic
fields up to 9 Tesla. A transition from oscillatory to reentrant behavior of
the superconducting transition temperature versus F-layers thickness, induced
by an external magnetic field, has been observed for the first time. In order
to properly interpret the experimental data, we develop a quasiclassical
theory, enabling one to evaluate the temperature dependence of the critical
field and the superconducting transition temperature for an arbitrary set of
the system parameters. A fairly good agreement between our experimental data
and theoretical predictions is demonstrated for all samples, using a single set
of fit parameters. This confirms adequacy of the
Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) physics in determining the unusual
superconducting properties of the studied Cu_{41}Ni_{59}/Nb/Cu_{41}Ni_{59}
spin-valve core trilayers.Comment: 16 pages, 7 figures; published versio
Re-entrant superconductivity in Nb/Cu(1-x)Ni(x) bilayers
We report on the first observation of a pronounced re-entrant
superconductivity phenomenon in superconductor/ferromagnetic layered systems.
The results were obtained using a superconductor/ferromagnetic-alloy bilayer of
Nb/Cu(1-x)Ni(x). The superconducting transition temperature T_{c} drops sharply
with increasing thickness d_{CuNi} of the ferromagnetic layer, until complete
suppression of superconductivity is observed at d_{CuNi}= 4 nm. Increasing the
Cu(1-x)Ni(x) layer thickness further, superconductivity reappears at
d_{CuNi}=13 nm. Our experiments give evidence for the pairing function
oscillations associated with a realization of the quasi-one dimensional
Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) like state in the ferromagnetic layer.Comment: 3 pages, 3 figures, REVTEX4/twocolum
Reentrant Superconductivity and Superconducting Critical Temperature Oscillations in F/S/F trilayers of Cu41Ni59/Nb/Cu41Ni59 Grown on Cobalt Oxide
Ferromagnet/Superconductor/Ferromagnet (F/S/F) trilayers constitute the core
of a superconducting spin valve. The switching effect of the spin valve is
based on interference phenomena occurring due to the proximity effect at the
S/F interfaces. A remarkable effect is only expected if the core structure
exhibits strong critical temperature oscillations, or most favorable, reentrant
superconductivity, when the thickness of the ferromagnetic layer is increased.
The core structure has to be grown on an antiferromagnetic oxide layer (or such
layer to be placed on top) to pin by exchange bias the
magnetization-orientation of one of the ferromagnetic layers. In the present
paper we demonstrate that this is possible, keeping the superconducting
behavior of the core structure undisturbed.Comment: 22 pages, 12 figures, 1 tabl
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