260 research outputs found
Hybrid Micro-Gravity Simulator Consisting of a High-speed Parallel Robot
科研費報告書収録論文(課題番号:08555062・基盤研究(A)(2)・H8~H10/研究代表者:内山, 勝/6自由度超高速パラレルロボットの試作研究
Social function of taxes as a toolkit for income differentiation reduction among population of the depressed republics of the North Caucasus Federal District
In the conditions of a difficult political situation, economic uncertainty and increasing unemployment in the land-poor manpower-surplus, depressive republics of the North Caucasus Federal District, the need to implement the entrepreneurial opportunities of the population is clearly manifested. It seems that small business can manifest itself in these conditions as a separate element of the economy decentralized sector. Of course, the success of small business in a depressed region depends on the state position to a large extent. And this is natural, because only the state is capable of creating the necessary conditions in market relations and various preference provision for the development of entrepreneurship, especially in the mountainous territories of the country.It should be noted that the next economic crisis and pandemic (coronavirus) not only led to the depletion of the state budget, but also collapsed the production activity of small diversified enterprises in the region. Most of the entrepreneurs of the North Caucasus Federal District declare that they are not able to independently solve the complex of this phenomenon negative consequences
Detailed study of the ac susceptibility of Sr2RuO4 in oriented magnetic fields
We have investigated the ac susceptibility of the spin triplet superconductor
SrRuO as a function of magnetic field in various directions at
temperatures down to 60 mK. We have focused on the in-plane field configuration
(polar angle ), which is a prerequisite for inducing
multiple superconducting phases in SrRuO. We have found that the
previous attribution of a pronounced feature in the ac susceptibility to the
second superconducting transition itself is not in accord with recent
measurements of the thermal conductivity or of the specific heat. We propose
that the pronounced feature is a consequence of additional involvement of
vortex pinning originating from the second superconducting transition.Comment: Accepted for publication in Phys. Rev.
Quasi-particle Density in Sr2RuO4 Probed by means of the Phonon Thermal Conductivity
The thermal conductivity of Sr2RuO4 along the least conducting direction
perpendicular to the RuO2 plane has been studied down to 0.3 K. In this
configuration the phonons remain the dominant heat carriers down to the lowest
temperature, and their conductivity in the normal state is determined by the
scattering on conduction electrons. We show that the phonon mean free path in
the superconducting state is sensitive to the density of the quasi-particles in
the bulk. An unusual magnetic field dependence of the phonon thermal
conductivity is ascribed to the anisotropic superconducting gap structure in
Sr2RuO4.Comment: 14 pages, 6 eps figures, Latex. This article corresponds to the
reference 25 of Phys. Rev. Lett. vol.86 page2649-2652 (2001) and
cond-mat/010449
Superconducting Properties under Magnetic Field in NaCoOHO Single Crystal
We report the in-plane resistivity and magnetic susceptibility of the layered
cobalt oxide NaCoOHO single crystal. The
temperature dependence of the resistivity shows metallic behavior from room
temperature to the superconducting transition temperature of 4.5 K.
Sharp resistive transition, zero resistivity and almost perfect superconducting
volume fraction below indicate the good quality and the bulk
superconductivity of the single crystal. The upper critical field and
the coherence length are obtained from the resistive transitions in
magnetic field parallel to the c-axis and the -plane. The anisotropy of
, 12 nm/1.3 nm 9.2, suggests that this
material is considered to be an anisotropic three dimensional superconductor.
In the field parallel to the -plane, seems to be suppressed to the
value of Pauli paramagnetic limit. It may indicate the spin singlet
superconductivity in the cobalt oxide.Comment: 4 pages, 4 figure
Interface superconductivity in the eutectic Sr2RuO4-Ru: 3-K phase of Sr2RuO4
The eutectic system Sr2RuO4-Ru is referred to as the 3-K phase of the
spin-triplet supeconductor Sr2RuO4 because of its enhanced superconducting
transition temperature Tc of ~3 K. We have investigated the field-temperature
(H-T) phase diagram of the 3-K phase for fields parallel and perpendicular to
the ab-plane of Sr2RuO4, using out-of-plane resistivity measurements. We have
found an upturn curvature in the Hc2(T) curve for H // c, and a rather gradual
temperature dependence of Hc2 close to Tc for both H // ab and H // c. We have
also investigated the dependence of Hc2 on the angle between the field and the
ab-plane at several temperatures. Fitting the Ginzburg-Landau effective-mass
model apparently fails to reproduce the angle dependence, particularly near H
// c and at low temperatures. We propose that all of these charecteric features
can be explained, at least in a qualitative fashion, on the basis of a theory
by Sigrist and Monien that assumes surface superconductivity with a
two-component order parameter occurring at the interface between Sr2RuO4 and Ru
inclusions. This provides evidence of the chiral state postulated for the 1.5-K
phase by several experiments.Comment: 7 pages and 5 figs; accepted for publication in Phys. Rev.
Vortex lattice structures and pairing symmetry in Sr2RuO4
Recent experimental results indicate that superconductivity in Sr2RuO4 is
described by the p-wave E_u representation of the D_{4h} point group. Results
on the vortex lattice structures for this representation are presented. The
theoretical results are compared with experiment.Comment: 4 pages, 3 figures, M2S-HTSC-VI proceeding
Spin-triplet superconductivity due to antiferromagnetic spin-fluctuation in Sr_2RuO_4
A mechanism leading to the spin-triplet superconductivity is proposed based
on the antiferromagnetic spin fluctuation. The effects of anisotropy in spin
fluctuation on the Cooper pairing and on the direction of d vector are examined
in the one-band Hubbard model with RPA approximation. The gap equations for the
anisotropic case are derived and applied to Sr_2RuO_4. It is found that a
nesting property of the Fermi surface together with the anisotropy leads to the
triplet superconductivity with the d=z(sin{k_x}\pm isin{k_y}), which is
consistent with experiments.Comment: 4 pages, 3 eps figures, revte
Gravitational Instabilities, Chondrule Formation, and the FU Orionis Phenomenon
Using analytic arguments and numerical simulations, we examine whether
chondrule formation and the FU Orionis phenomenon can be caused by the
burst-like onset of gravitational instabilities (GIs) in dead zones. At least
two scenarios for bursting dead zones can work, in principle. If the disk is on
the verge of fragmention, GI activation near to 5 AU can produce
chondrule-forming shocks, at least under extreme conditions. Mass fluxes are
also high enough during the onset of GIs to suggest that the outburst is
related to an FU Orionis phenomenon. This situation is demonstrated by
numerical simulations. In contrast, as supported by analytic arguments, if the
burst takes place close to AU, then even low pitch angle spiral waves
can create chondrule-producing shocks and outbursts. We also study the
stability of the massive disks in our simulations against fragmentation and
find that although disk evolution is sensitive to changes in opacity, the disks
we study do not fragment, even at high resolution and even for extreme
assumptions.Comment: To appear in Ap
A critical review of the impacts of cover crops on nitrogen leaching, net greenhouse gas balance and crop productivity
This work contributes to the UK-China Virtual Joint Centre N-Circle (grant number BB/N013484/1), SuperG (funded under EU Horizon 2020 programme) and ADVENT (grant number NE/M019691/1). DRC was supported by the UK-China Virtual joint Centre for Agricultural Nitrogen (CINAg, BB/N013468/1) and the UK-Brazil Virtual Joint Centre to deliver enhanced N-use efficiency via an integrated soil-plant systems approach (NUCLEUS), which are jointly supported by Newton fund via UK BBSRC and NERC. Jaak Truu received financing from Estonian Research Council (grant PRG548).Peer reviewedPublisher PD
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