49,001 research outputs found
Electronic Structure Calculations of Magnetic Exchange Interactions in Europium Monochalcogenides
Using a combination of local spin density and Hubbard 1 approximations we
study the mechansim of exchange interacion in EuX (X=O, S, Se and Te). We
reproduce known experimental results about bulk modulus, critical pressure for
structural phase transition, magnetic ordering temperature, spin--wave
dispersions as well as momentum-- and tempearuture--dependent band shift. Our
numerical results show pressure induced competition between the hybirization
enhanced exchange interaction and Kondo--like coupling in EuO. Possible ways to
enhance T_{c} are discussed
Modular Invariance for Twisted Modules over a Vertex Operator Superalgebra
The purpose of this paper is to generalize Zhu's theorem about characters of
modules over a vertex operator algebra graded by integer conformal weights, to
the setting of a vertex operator superalgebra graded by rational conformal
weights. To recover SL_2(Z)-invariance of the characters it turns out to be
necessary to consider twisted modules alongside ordinary ones. It also turns
out to be necessary, in describing the space of conformal blocks in the
supersymmetric case, to include certain `odd traces' on modules alongside
traces and supertraces. We prove that the set of supertrace functions, thus
supplemented, spans a finite dimensional SL_2(Z)-invariant space. We close the
paper with several examples.Comment: 42 pages. Published versio
Modeling quark-hadron duality in polarization observables
We apply a model for the study of quark-hadron duality in inclusive electron
scattering to the calculation of spin observables. The model is based on
solving the Dirac equation numerically for a scalar confining linear potential
and a vector color Coulomb potential. We qualitatively reproduce the features
of quark-hadron duality for all potentials considered, and discuss the onset of
scaling and duality for the responses, spin structure functions, and
polarization asymmetries. Duality may be applied to gain access to kinematic
regions which are hard to access in deep inelastic scattering, namely for
, and we discuss which observables are most suitable for this
application of duality
Spin interference and Fano effect in electron transport through a mesoscopic ring side-coupled with a quantum dot
We investigate the electron transport through a mesoscopic ring side-coupled
with a quantum dot(QD) in the presence of Rashba spin-orbit(SO) interaction. It
is shown that both the Fano resonance and the spin interference effects play
important roles in the electron transport properties. As the QD level is around
the Fermi energy, the total conductance shows typical Fano resonance line
shape. By applying an electrical gate voltage to the QD, the total transmission
through the system can be strongly modulated. By threading the mesoscopic ring
with a magnetic flux, the time-reversal symmetry of the system is broken, and a
spin polarized current can be obtained even though the incident current is
unpolarized.Comment: 5 pages, 5 figure
Hydrogen-bonded liquid crystals with broad-range blue phases
We report a modular supramolecular approach for the investigation of chirality induction in hydrogen-bonded liquid crystals. An exceptionally broad blue phase with a temperature range of 25 °C was found, which enabled its structural investigation by solid state 19F-NMR studies and allowed us to report order parameters of the blue phase I for the first time
One Belt - One Road Initiative: A Window of Opportunity for Russia's Western Border Region
In recent years, global geo-economic transformations have been considerably affected by the development of the People’s Republic of China, its reviving leadership and ambitions, and its increasing efforts to reformat and integrate the Eurasian space. The One Belt — One Road Initiative is a manifesto and a tool to advance China’s long-term geostrategic interests that spread to the bordering states and regions and to the prospects of their socioeconomic development. The initiative encompasses transportation and logistics, production and investment, finances, research and technology, humanitarian affairs, and foreign policy. In this article, we will highlight the key geoeconomic and geopolitical aspects of the One Belt — One Road initiative implementation, based on the Chinese and Russian studies. Another goal is to weigh up the risks and benefits associated with the extension of the project to Russian territories. Special attention is paid to Russia’s western borderlands — 17 regions that account for 8.6 % of the country’s territory, 17.4 % of the total GRP, and 20.8 % of the national population. We analyse the factors in effect — including geopolitical ones, as well as current trends in the development of Russia’s western borderlands. It is shown that the inclusion into the Chinese Eurasian integration initiatives creates additional incentives for a positive re-evaluation of the Russian space as a whole and holds special relevance for Russia’s western borderlands. We analyse the possibility of including Russia’s Baltic regions — the infrastructural and economic island of the Kaliningrad exclave among them — into the One Belt — One Road Initiative
Customer information systems for deregulated ASEAN countries
In similar fashion to western countries, ASEAN countries are also gearing up towards deregulation. Despite potentially different motivating drivers, the ultimate objectives are free market competition leading to efficient pricing signals as well as providing customers with the freedom to choose their electricity provider and benefit from competitive prices. This paper provides an ASEAN electricity market analysis and describes the development of electricity deregulation in ASEAN countries. By way of background it also highlights the objectives of deregulation, the potential challenges and also the impact areas focusing on existing Customer Information Systems (CIS) that have been developed by other utilities. In addition, this paper proposes a new framework for improving CIS for ASEAN utilities facing deregulation. The framework outlines a CIS, which has intelligent features enabling the utility to estimate and predict customer behaviour with respect to consumption patterns. It describes how these features can assist the utility companies to retain their existing customers as well as attract more customers
Evolution of worldwide stock markets, correlation structure and correlation based graphs
We investigate the daily correlation present among market indices of stock
exchanges located all over the world in the time period Jan 1996 - Jul 2009. We
discover that the correlation among market indices presents both a fast and a
slow dynamics. The slow dynamics reflects the development and consolidation of
globalization. The fast dynamics is associated with critical events that
originate in a specific country or region of the world and rapidly affect the
global system. We provide evidence that the short term timescale of correlation
among market indices is less than 3 trading months (about 60 trading days). The
average values of the non diagonal elements of the correlation matrix,
correlation based graphs and the spectral properties of the largest eigenvalues
and eigenvectors of the correlation matrix are carrying information about the
fast and slow dynamics of correlation of market indices. We introduce a measure
of mutual information based on link co-occurrence in networks, in order to
detect the fast dynamics of successive changes of correlation based graphs in a
quantitative way.Comment: 8 pages, 11 figure
- …