315 research outputs found
Angular dependent magnetothermopower of alpha-(ET)2KHg(SCN)4
The magnetic field and angular dependencies of the thermopower and Nernst
effect of the quasi-two-dimensional organic conductor alpha-(ET)2KHg(SCN)4 are
experimentally measured at temperatures below (4 K) and above (9 K) the
transition temperature to fields of In addition, a theoretical model which
involves a magnetic breakdown effect between the q1D and q2D bands is proposed
in order to simulate the data. Analysis of the background components of the
thermopower and Nernst effect imply that at low temperatures, in the CDW state,
the properties of alpha-(ET)2KHg(SCN)4 are determined mostly by the orbits on
the new open Fermi sheets. Quantum oscillations observed in the both
thermoelectric effects, at fields above 8 T, originate only from the alpha
orbit.Comment: 25 pages, 18 figure
Unit Killing Vector Fields on Nearly Kahler Manifolds
We study 6-dimensional nearly Kahler manifolds admitting a Killing vector
field of unit length. In the compact case it is shown that up to a finite cover
there is only one geometry possible, that of the 3--symmetric space
Zinc oxide-nickel cermet selective coatings obtained by sequential electrodeposition
The investigation of pulse electrodepositing modes influence on crystal structure, morphology and optical properties of ZnO has revealed the conditions in which quasi-one-dimensional (1D) ZnO nanorod arrays are formed as separate nanorods. Due to a sufficiently high resistance of zinc oxide, the electrodeposition of nickel on the fluorine doped tin oxide (FTO)/ZnO surfaces carried out in space between the ZnO nanorods. An incomplete filling of the gaps between nanorods by the nickel nanoparticles through subsequent Ni electrodeposition ensured the creation of ZnO–Ni graded cermets. The cermets, in which electrochemical filling of the spaces between ZnO nanorods by Ni, was performed in the pulse mode. It provided higher absorption of visible and near IR light. It was shown that the manufactured ZnO–Ni graded cermets have high light absorption combined with comparatively low thermal losses, so these cermets are promising cheap and affordable selective coatings for solar heat collectors
Analytical aspects of anti-crisis measures of public administration
The study of crises is one of the most important areas of economic science. Sanctions against Russia in 2022 have led to significant functional and structural shifts in the national economy. Effective anti-crisis management in crisis conditions becomes one of the main directions of its overcoming in Russian economy. The issues of improving the mechanism of crisis management at the present historical stage are actualised. The purpose is study of anti-crisis management methods for the development of an effective anti-crisis mechanism. Objectives is to study the existing methods of anti-crisis management in the light of international experience. The authors used methods of analysis, synthesis and comparison, and abstract-logical method in the research. The analytical method of information processing, synthesis and deduction of theoretical aspects of the concept of crisis and crisis management was carried out. A study of methods of crisis management, considering international experience, systematization and analysis of existing principles of state crisis management of the economy was carried out. The content and role of modern methods of crisis management deserves special attention. In the context of the sanctions announced against Russia, it is necessary to develop more advanced approaches to crisis management. The model of the anti-crisis mechanism for building an effective management system in the country’s economy is considered
Pressure-induced unconventional superconductivity in the heavy-fermion antiferromagnet CeIn3: An 115In-NQR study under pressure
We report on the pressure-induced unconventional superconductivity in the
heavy-fermion antiferromagnet CeIn3 by means of nuclear-quadrupole-resonance
(NQR) studies conducted under a high pressure. The temperature and pressure
dependences of the NQR spectra have revealed a first-order quantum-phase
transition (QPT) from an AFM to PM at a critical pressure Pc=2.46 GPa. Despite
the lack of an AFM quantum critical point in the P-T phase diagram, we
highlight the fact that the unconventional SC occurs in both phases of the AFM
and PM. The nuclear spin-lattice relaxation rate 1/T1 in the AFM phase have
provided evidence for the uniformly coexisting AFM+SC phase. In the HF-PM phase
where AFM fluctuations are not developed, 1/T1 decreases without the coherence
peak just below Tc, followed by a power-law like T dependence that indicates an
unconventional SC with a line-node gap. Remarkably, Tc has a peak around Pc in
the HF-PM phase as well as in the AFM phase. In other words, an SC dome exists
with a maximum value of Tc = 230 mK around Pc, indicating that the origin of
the pressure-induced HF SC in CeIn3 is not relevant to AFM spin fluctuations
but to the emergence of the first-order QPT in CeIn3. When the AFM critical
temperature is suppressed at the termination point of the first-order QPT, Pc =
2.46 GPa, the diverging AFM spin-density fluctuations emerge at the critical
point from the AFM to PM. The results with CeIn3 leading to a new type of
quantum criticality deserve further theoretical investigations
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