3,073 research outputs found
The apparent Fermi liquid concept helps to understand thermoelectric materials
Invited expert opinion on the article S. Kremer and R. Fresard, Ann. Phys.
(Berlin) 524, 21 (2012).Comment: 3 pages, 1 figur
Exploring Millions of 6-State FSSP Solutions: the Formal Notion of Local CA Simulation
In this paper, we come back on the notion of local simulation allowing to
transform a cellular automaton into a closely related one with different local
encoding of information. This notion is used to explore solutions of the Firing
Squad Synchronization Problem that are minimal both in time (2n -- 2 for n
cells) and, up to current knowledge, also in states (6 states). While only one
such solution was proposed by Mazoyer since 1987, 718 new solutions have been
generated by Clergue, Verel and Formenti in 2018 with a cluster of machines. We
show here that, starting from existing solutions, it is possible to generate
millions of such solutions using local simulations using a single common
personal computer
Intergrowth and thermoelectric properties in the Bi-Ca-Co-O system
Single crystals of the Bi-Ca-Co-O system have been grown using the flux
method with cooling from 900\celsius and 950\celsius, respectively. The
single crystals are characterized by transmission electron microscopy and X-ray
diffraction. The misfit cobaltite
[CaBiCoO][CoO] single crystals with
quadruple (=4) rocksalt (RS) layer are achieved with cooling from
900\celsius. Such crystal exhibits room-temperature thermoelectric power
(TEP) of 180V/K, much larger than that in Sr-based misfit cobaltites with
quadruple RS layer. However, intergrowth of single crystals of quadruple
(=4) and triple (=3) RS-type layer-based misfit cobaltites is observed
with cooling from 950\celsius. Both of TEP and resistivity were obviously
enhanced by the intergrowth compared to
[CaBiCoO][CoO] single crystal,
while the power factor at room temperature remains unchanged.Comment: 8 pages, 7 figures. To be published in Journal of Crystal Growt
Interest rates mapping
The present study deals with the analysis and mapping of Swiss franc interest
rates. Interest rates depend on time and maturity, defining term structure of
the interest rate curves (IRC). In the present study IRC are considered in a
two-dimensional feature space - time and maturity. Geostatistical models and
machine learning algorithms (multilayer perceptron and Support Vector Machines)
were applied to produce interest rate maps. IR maps can be used for the
visualisation and patterns perception purposes, to develop and to explore
economical hypotheses, to produce dynamic asses-liability simulations and for
the financial risk assessments. The feasibility of an application of interest
rates mapping approach for the IRC forecasting is considered as well.Comment: 8 pages, 8 figures. Presented at Applications of Physics in Financial
Analysis conference (APFA6), Lisbon, Portugal, 200
Anisotropic susceptibility of the geometrically frustrated spin-chain compound Ca3Co2O6
Ca3Co2O6 is a system exhibiting a series of fascinating properties, including
magnetization plateaus and remarkably slow dynamics at low-T. These properties
are intimately related to the geometrical frustration, which results from a
particular combination of features: (i) the chains are arranged on a triangular
lattice; (ii) there is a large uniaxial anisotropy; (iii) the intrachain and
interchain couplings are ferromagnetic and antiferromagnetic, respectively.
The uniaxial anisotropy is thus an issue of crucial importance for the
analysis of the physical properties of Ca3Co2O6. However, it turns out that no
precise investigation of this magnetic anisotropy has been performed so far. On
the basis of susceptibility data directly recorded on single crystals, the
present study reports on quantitative information about the anisotropy of
Ca3Co2O6.Comment: 10 pages, 5 figure
Unconventional aspects of electronic transport in delafossite oxides
The electronic transport properties of the delafossite oxides ABO are
usually understood in terms of two well separated entities, namely, the
triangular A and (BO) layers. Here we review several cases among
this extensive family of materials where the transport depends on the
interlayer coupling and displays unconventional properties. We review the doped
thermoelectrics based on CuRhO and CuCrO, which show a high-temperature
recovery of Fermi-liquid transport exponents, as well as the highly anisotropic
metals PdCoO, PtCoO and PdCrO where the sheer simplicity of the
Fermi surface leads to unconventional transport. We present some of the
theoretical tools that have been used to investigate these transport properties
and review what can and cannot be learned from the extensive set of electronic
structure calculations that have been performed.Comment: 35 pages, 19 figure
Joseph de Maistre, la polyphonie païenne et la nymphe christique
National audienceAccording to some critics, Joseph de Maistre was a pagan because he did not worship Jesus-Christ enough. Others considered Maistre was a real catholic who just did not care about the ancients. I did a lot of research on Maistre's readings and believe there is a lot of original and erudite paganism in his books, which is not expressed as prayers to Jupiter but rather as a rhetorical, philosophical, religious and poetical language.Informés par une recherche sur les lectures antiques de Joseph de Maistre, nous étudions ici les usages du paganisme dans son oeuvre. Ce paganisme est paradoxal chez un écrivain considéré comme parfaitement catholique, mais il lui sert à la fois de polémique contre les modernes, de philosophie de la nature, de foi dans la pluralité des manifestations du divin et de poétique
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