6,967 research outputs found
Symmetry breaking and unconventional charge ordering in single crystal NaRuO
The interplay of charge, spin, and lattice degrees of freedom in matter leads
to various forms of ordered states through phase transitions. An important
subclass of these phenomena of complex materials is charge ordering (CO),
mainly driven by mixed-valence states. We discovered by combining the results
of electrical resistivity (), specific heat, susceptibility
(\textit{T}), and single crystal x-ray diffraction (SC-XRD) that
NaRuO with the monoclinic tunnel type lattice (space group
2/) exhibits an unconventional CO at room temperature while retaining
metallicity. The temperature-dependent SC-XRD results show successive phase
transitions with super-lattice reflections at \textbf{q}=(0, ,
0) and \textbf{q}=(0, , ) below
(365 K) and only at \textbf{q}=(0, , 0) between
and (630 K). We interpreted these as an
evidence for the formation of an unconventional CO. It reveals a strong
first-order phase transition in the electrical resistivity at
(cooling) = 345 K and (heating) = 365 K. We argue that the
origin of the phase transition is due to the localized 4 Ru-electrons. The
results of our finding reveal an unique example of Ru/Ru mixed
valance heavy \textit{d} ions.Comment: 10 pages, 9 figure
Postfledging Survival, Movements, and Dispersal of Ring Ouzels (Turdus torquatus)
We thank Invercauld Estate for cooperation with access to Glen Clunie. S. Redpath, J. Wilson, and S. Roos provided valuable comments on the manuscript. This study was funded by the Royal Society for the Protection of Birds, Scottish Natural Heritage, and the Cairngorms National Park Authority. J.L.L. was supported by the Natural Environment Research Council.Peer reviewedPublisher PD
Moments of spectral functions: Monte Carlo evaluation and verification
The subject of the present study is the Monte Carlo path-integral evaluation
of the moments of spectral functions. Such moments can be computed by formal
differentiation of certain estimating functionals that are
infinitely-differentiable against time whenever the potential function is
arbitrarily smooth. Here, I demonstrate that the numerical differentiation of
the estimating functionals can be more successfully implemented by means of
pseudospectral methods (e.g., exact differentiation of a Chebyshev polynomial
interpolant), which utilize information from the entire interval . The algorithmic detail that leads to robust numerical
approximations is the fact that the path integral action and not the actual
estimating functional are interpolated. Although the resulting approximation to
the estimating functional is non-linear, the derivatives can be computed from
it in a fast and stable way by contour integration in the complex plane, with
the help of the Cauchy integral formula (e.g., by Lyness' method). An
interesting aspect of the present development is that Hamburger's conditions
for a finite sequence of numbers to be a moment sequence provide the necessary
and sufficient criteria for the computed data to be compatible with the
existence of an inversion algorithm. Finally, the issue of appearance of the
sign problem in the computation of moments, albeit in a milder form than for
other quantities, is addressed.Comment: 13 pages, 2 figure
Deflagrations in hybrid CONe white dwarfs: a route to explain the faint Type Iax supernova 2008ha
Stellar evolution models predict the existence of hybrid white dwarfs (WDs)
with a carbon-oxygen core surrounded by an oxygen-neon mantle. Being born with
masses ~1.1 Msun, hybrid WDs in a binary system may easily approach the
Chandrasekhar mass (MCh) by accretion and give rise to a thermonuclear
explosion. Here, we investigate an off-centre deflagration in a near-MCh hybrid
WD under the assumption that nuclear burning only occurs in carbon-rich
material. Performing hydrodynamics simulations of the explosion and detailed
nucleosynthesis post-processing calculations, we find that only 0.014 Msun of
material is ejected while the remainder of the mass stays bound. The ejecta
consist predominantly of iron-group elements, O, C, Si and S. We also calculate
synthetic observables for our model and find reasonable agreement with the
faint Type Iax SN 2008ha. This shows for the first time that deflagrations in
near-MCh WDs can in principle explain the observed diversity of Type Iax
supernovae. Leaving behind a near-MCh bound remnant opens the possibility for
recurrent explosions or a subsequent accretion-induced collapse in faint Type
Iax SNe, if further accretion episodes occur. From binary population synthesis
calculations, we find the rate of hybrid WDs approaching MCh to be on the order
of 1 percent of the Galactic SN Ia rate.Comment: 9 pages, 7 figures, 2 tables, accepted for publication in MNRA
Conteúdos linguísticos como subsídio à formação de professores alfabetizadores: a experiência do Brasil e de Portugal
Objetiva identificar em dois programas de formação de professores
alfabetizadores – no Brasil, Pacto Nacional pela Alfabetização na Idade Certa (Pnaic) e, em Portugal, Programa Nacional do Ensino do Português (Pnep) – os conteúdos linguísticos relacionados ao ensino da leitura que fundamentaram a atualização dos professores com vistas a compreender como as descobertas científicas penetram o campo pedagógico. Por meio de análise documental, são apresentadas, de forma resumida, a estrutura e a organização dos dois programas e os respectivos conteúdos de formação. Há muita similaridade entre os dois programas com relação à organização e às estratégias metodológicas e há diferenças importantes quanto à atualidade dos conteúdos oferecidos aos professores alfabetizadores, assim como o tempo de formação aplicado a este conteúdo. A formação linguística do professor é essencial para desenvolver competência para o ensino da língua e, por conseguinte, melhorar as habilidades de ler e escrever dos alunos do ensino fundamental.This article aims to identify the linguistic contents related to the
teaching of reading in two training programs for literacy teachers: Brazil’s
National Pact for Literacy at the Right Age (Pacto Nacional pela Alfabetização
na Idade Certa – Pnaic) and the National Program for Portuguese Teaching
(Programa Nacional do Ensino do Português – Pnep) of Portugal. The focus
is on the linguistic contents that served as foundation for the updating
of teachers, in order to understand how scientific discoveries permeate
the teaching field. Through documentary analysis, the structure and the
organization of the two programs and their respective training contents are
briefly presented. There are many similarities between the two programs,
regarding the organization and the methodological strategies; but there are
also differences in relation to the timeliness of the content offered to the
literacy teachers, as well as to the duration of the training applied to the
content. The linguistic training of teachers is essential to developing the
competence for language teaching and, therefore; for the improvement of
reading and writing skills of elementary school students.CIEC - Centro de Investigação em Estudos da Criança, IE, UMinho (UI 317 da FCT), PortugalFundos Nacionais através da FCT (Fundação para a Ciência e a Tecnologia) e cofinanciado pelo Fundo Europeu de Desenvolvimento Regional (FEDER) através do COMPETE 2020 – Programa Operacional Competitividade e Internacionalização (POCI) com a referência POCI-01-0145-FEDER-007562info:eu-repo/semantics/publishedVersio
Estudi de la brioflora dels Ports de Beseit
A catalog of the 186 bryophytic taxa found in the calcareous mountain area of the Ports de Beseit is given, together with a short description of the bryological vegetation, and comments on interesting species such as Acaulon dertosense, Frullania muscicolu, Brachythecium olympicum, Rhynchostegiella compacta, Tortula solmsii, etc. Chorological and ecological spectra are also given.Presentem el catàleg dels 186 taxons briofítics trobats als Ports de Beseit, junt amb una succinta descripció de la vegetació briofítica i comentaris sobre certes especies interessants, com ara Acaulon dertosense, Frullania muscicola, Brachythecium olympicum, Rhynchostegiella compacta, Tortula solmsii, etc. Donem també els espectres corologies i de diversos factors ecologies
Mindfulness facets, trait emotional intelligence, emotional distress, and multiple health behaviors: A serial two-mediator model.
In the present study, we tested a serial mindfulness facets-trait emotional intelligence (TEI)-emotional distress-multiple health behaviors mediation model in a sample of N = 427 German-speaking occupational therapists. The mindfulness facets-TEI-emotional distress section of the mediation model revealed partial mediation for the mindfulness facets Act with awareness (Act/Aware) and Accept without judgment (Accept); inconsistent mediation was found for the Describe facet. The serial two-mediator model included three mediational pathways that may link each of the four mindfulness facets with multiple health behaviors. Eight out of 12 indirect effects reached significance and fully mediated the links between Act/Aware and Describe to multiple health behaviors; partial mediation was found for Accept. The mindfulness facet Observe was most relevant for multiple health behaviors, but its relation was not amenable to mediation. Implications of the findings will be discussed
Deficiencies in the transfer and availability of clinical trials evidence: A review of existing systems and standards
Background: Decisions concerning drug safety and efficacy are generally based on pivotal evidence provided by clinical trials. Unfortunately, finding the relevant clinical trials is difficult and their results are only available in text-based reports. Systematic reviews aim to provide a comprehensive overview of the evidence in a specific area, but may not provide the data required for decision making. Methods: We review and analyze the existing information systems and standards for aggregate level clinical trials information from the perspective of systematic review and evidence-based decision making. Results: The technology currently used has major shortcomings, which cause deficiencies in the transfer, traceability and availability of clinical trials information. Specifically, data available to decision makers is insufficiently structured, and consequently the decisions cannot be properly traced back to the underlying evidence. Regulatory submission, trial publication, trial registration, and systematic review produce unstructured datasets that are insufficient for supporting evidence-based decision making. Conclusions: The current situation is a hindrance to policy decision makers as it prevents fully transparent decision making and the development of more advanced decision support systems. Addressing the identified deficiencies would enable more efficient, informed, and transparent evidence-based medical decision making
Time-stepping beyond CFL: a locally one-dimensional scheme for acoustic wave propagation
In this abstract, we present a case study in the application of a time-stepping method, unconstrained by the CFL condition, for computational acoustic wave propagation in the context of full waveform inversion. The numerical scheme is a locally one-dimensional (LOD) variant of alternating dimension implicit (ADI) method. The LOD method has a maximum time step that is restricted only by the Nyquist sampling rate. The advantage over traditional explicit time-stepping methods occurs in the presence of high contrast media, low frequencies, and steep, narrow perfectly matched layers (PML). The main technical point of the note, from a numerical analysis perspective, is that the LOD scheme is adapted to the presence of a PML. A complexity study is presented and an application to full waveform inversion is shown.National Science Foundation (U.S.); Alfred P. Sloan Foundatio
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