120 research outputs found
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Experimental study of laboratory-heated CM2 chondrites Mighei and Murchison
We conducted experimental heating of two CM2 chondrites, Murchison and Mighei, to study changes in their oxygen isotopic compositions and mineralogy and explore possible genetic relationships between MCCs and normal CMs
The Driver of Development and Transformation of Global Oil and Gas Business in Digital Economy’s Conditions
The digitalization of the oil and gas sector is the strong driver for Russian economy increasing efficiency. The main purpose of this study is to find out the main digitalization development trends of the oil and gas sector and the growth barriers and effects in Russian oil and gas industry in modern digital economy conditions. The results of this study show options of digital technology using in oil and gas sector in Russia
The Regional Tax Security Mechanism Based on Reduction of Tax Risks and Use of Information Technologies
In today’s world taxes tend to be not only a tool for ensuring and maintaining economic and financial security, but also a source of possible threats and risks which may result in reduction of tax potential and budgetary imbalances between the central office and the provinces. In the conditions of economy digitalization, tax security as a prospective way of optimal modern tax management in the state and its regions includes elements of tax mechanism, information technology and technology of tax information protection. This article advocates the need for legislative recognition of the term "tax security", structures the components of tax security threats identification, which include elements of risk management and directions of tax administration improvement. Within the framework of the study of the tax security system, the functional relationship between tax risks and the structural elements of the tax mechanism, including its planning, regulatory, controlling and analytical components, was determined
Weak Charge Quantization on Superconducting Islands
We consider the Coulomb blockade on a superconductive quantum dot strongly
coupled to a lead through a tunnelling barrier and/or normal diffusive metal.
Andreev transport of the correlated pairs leads to quantum fluctuations of the
charge on the dot. These fluctuations result in exponential renormalization of
the effective charging energy. We employ two complimentary ways to approach the
problem, leading to the coinciding results: the instanton and the functional RG
treatment of the non-linear sigma model. We also derive the charging energy
renormalization in terms of arbitrary transmission matrix of the multi-channel
interface.Comment: 21 pages, 4 eps figures, RevTe
Shot noise in tunneling transport through molecules and quantum dots
We consider electrical transport through single molecules coupled to metal
electrodes via tunneling barriers. Approximating the molecule by the Anderson
impurity model as the simplest model which includes Coulomb charging effects,
we extend the ``orthodox'' theory to expand current and shot noise
systematically order by order in the tunnel couplings. In particular, we show
that a combined measurement of current and shot noise reveals detailed
information of the system even in the weak-coupling limit, such as the ratio of
the tunnel-coupling strengths of the molecule to the left and right electrode,
and the presence of the Coulomb charging energy. Our analysis holds for
single-level quantum dots as well.Comment: 8 page
Состояние здоровья школьников в условиях мегаполиса и села
In article comparative research a state of the schoolboys health living and trained in different social and ecological conditions of a capital megacity, city around Moscow and village scales is resulted. The description of ecological conditions of some areas of a capital megacity, a city situated near Moscow and village of the Kaluga region is given. The data on level and in frequency of occurrence of diseases among schoolboys of different age groups of conditions of a city and village is cited. On the basis of the received results different groups on level of adaptation and levels of psychosomatic health are revealed.Проведено сравнительное исследование состояние здоровья школьников, проживающих и обучающихся в разных социально-экологических условиях столичного мегаполиса, среднего по масштабам города и села. Дается описание экологической обстановки некоторых районов столичного мегаполиса, подмосковного города и села Калужской области. Приведены данные по уровню и частоте встречаемости заболеваний среди школьников разных возрастных групп условий города и села. На основании полученных результатов выявлены разные группы по уровню адаптации и уровням психосоматического здоровья
Resonant multiple Andreev reflections in mesoscopic superconducting junctions
We investigate the properties of subharmonic gap structure (SGS) in
superconducting quantum contacts with normal-electron resonances. We find two
distinct new features of the SGS in resonant junctions which distinguish them
from non-resonant point contacts: (i) The odd-order structures on the
current-voltage characteristics of resonant junctions are strongly enhanced and
have pronounced peaks, while the even-order structures are suppressed, in the
case of a normal electron resonance being close to the Fermi level. (ii)
Tremendous current peaks develop at where indicates a
distance of the resonance to the Fermi level. These properties are determined
by the effect of narrowing of the resonance during multiple Andreev reflections
and by overlap of electron and hole resonances.Comment: 13 pages, 10 figure
Quantum Disorder and Quantum Chaos in Andreev Billiards
We investigate the crossover from the semiclassical to the quantum
description of electron energy states in a chaotic metal grain connected to a
superconductor. We consider the influence of scattering off point impurities
(quantum disorder) and of quantum diffraction (quantum chaos) on the electron
density of states. We show that both the quantum disorder and the quantum chaos
open a gap near the Fermi energy. The size of the gap is determined by the mean
free time in disordered systems and by the Ehrenfest time in clean chaotic
systems. Particularly, if both times become infinitely large, the density of
states is gapless, and if either of these times becomes shorter than the
electron escape time, the density of states is described by random matrix
theory. Using the Usadel equation, we also study the density of states in a
grain connected to a superconductor by a diffusive contact.Comment: 20 pages, 10 figure
Centrality dependence of charged particle production at large transverse momentum in Pb-Pb collisions at TeV
The inclusive transverse momentum () distributions of primary
charged particles are measured in the pseudo-rapidity range as a
function of event centrality in Pb-Pb collisions at
TeV with ALICE at the LHC. The data are presented in the range
GeV/ for nine centrality intervals from 70-80% to 0-5%.
The Pb-Pb spectra are presented in terms of the nuclear modification factor
using a pp reference spectrum measured at the same collision
energy. We observe that the suppression of high- particles strongly
depends on event centrality. In central collisions (0-5%) the yield is most
suppressed with at -7 GeV/. Above
GeV/, there is a significant rise in the nuclear modification
factor, which reaches for GeV/. In
peripheral collisions (70-80%), the suppression is weaker with almost independently of . The measured nuclear
modification factors are compared to other measurements and model calculations.Comment: 17 pages, 4 captioned figures, 2 tables, authors from page 12,
published version, figures at
http://aliceinfo.cern.ch/ArtSubmission/node/284
Anisotropic flow of charged hadrons, pions and (anti-)protons measured at high transverse momentum in Pb-Pb collisions at TeV
The elliptic, , triangular, , and quadrangular, , azimuthal
anisotropic flow coefficients are measured for unidentified charged particles,
pions and (anti-)protons in Pb-Pb collisions at TeV
with the ALICE detector at the Large Hadron Collider. Results obtained with the
event plane and four-particle cumulant methods are reported for the
pseudo-rapidity range at different collision centralities and as a
function of transverse momentum, , out to GeV/.
The observed non-zero elliptic and triangular flow depends only weakly on
transverse momentum for GeV/. The small dependence
of the difference between elliptic flow results obtained from the event plane
and four-particle cumulant methods suggests a common origin of flow
fluctuations up to GeV/. The magnitude of the (anti-)proton
elliptic and triangular flow is larger than that of pions out to at least
GeV/ indicating that the particle type dependence persists out
to high .Comment: 16 pages, 5 captioned figures, authors from page 11, published
version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/186
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