807 research outputs found
Point-contact spectroscopy of Al- and C-doped MgB2. Superconducting energy gaps and scattering studies
The two-band/two-gap superconductivity in aluminium and carbon doped MgB
has been addressed by the point-contact spectroscopy. Two gaps are preserved in
all samples with down to 22 K. The evolution of two gaps as a function
of the critical temperature in the doped systems suggest the dominance of the
band-filling effects but for the increased Al-doping the enhanced interband
scattering approaching two gaps must be considered. The magnetic field
dependences of the Andreev reflection excess currents as well as zero-energy
density of states determined from the experimental data are used to analyze the
intraband scattering. It is shown, that while the C-doping increases the
intraband scattering in the -band more rapidly then in the band,
the Al-doping does not change their relative weight.Comment: 8 pages, incl. 6 figure
Type II superconductivity in SrPd2Ge2
Previous investigations have shown that SrPd2Ge2, a compound isostructural
with "122" iron pnictides but iron- and pnictogen-free, is a conventional
superconductor with a single s-wave energy gap and a strongly three-dimensional
electronic structure. In this work we reveal the Abrikosov vortex lattice
formed in SrPd2Ge2 when exposed to magnetic field by means of scanning
tunneling microscopy and spectroscopy. Moreover, by examining the differential
conductance spectra across a vortex and estimating the upper and lower critical
magnetic fields by tunneling spectroscopy and local magnetization measurements,
we show that SrPd2Ge2 is a strong type II superconductor with \kappa >>
sqrt(2). Also, we compare the differential conductance spectra in various
magnetic fields to the pair breaking model of Maki - de Gennes for dirty limit
type II superconductor in the gapless region. This way we demonstrate that the
type II superconductivity is induced by the sample being in the dirty limit,
while in the clean limit it would be a type I superconductor with \kappa\ <<
sqrt(2), in concordance with our previous study (T. Kim et al., Phys. Rev. B
85, (2012)).Comment: 9 pages, 4 figure
Susceptibility of European pear cultivars to Venturia pirina Aderh. infection at a variety collection in Hungary
Field sensitivity of 271 European pear genotypes were evaluated in a large variety collection of pear in Hungary during a nine years survey. Substantial differences were detected in the rate of pear scab infection of leaves and fruits. Some 18 per cent of the inspected genotypes remained completely free of infection even in the years with weather favouring to the disease. On the other hand, 78 % of the inspected genotypes were infected in some or more extent. The rate of infection was generally higher on leaves than on fruits. 18.6 % of the genotypes inspected were tolerant to leaf infection and their majority (81.1 %) were tolerant to fruit infection. Some one fi fth of the genotypes (19.7 %) were highly susceptible to leaf infection but only minor rate of them (2.2 %) were highly susceptible to fruit infection. There were 44 genotypes that could be regarded as tolerant to pear scab leaf and fruit infection under fi eld conditions. Some of these genotypes may be suitable to commercial pear growing with highly reduced chemical control against pear but their yield capacity and fruit quality should be evaluated
The additional-mode garden of RR Lyrae stars
Space-based photometric missions revealed a surprising abundance of
millimagnitude-level additional modes in RR Lyrae stars. The modes that appear
in the modulated fundamental-mode (RRab) stars can be ordered into four major
categories. Here we present the distribution of these groups in the Petersen
diagram, and discuss their characteristics and connections to additional modes
observed in other RR Lyrae stars.Comment: 4 pages, 4 figures, proceedings of the Joint
TASC2-KASC9-SPACEINN-HELAS8 Conference "Seismology of the Sun and the Distant
Stars 2016", to be published in EPJ Wo
Single gap superconductivity in beta-Bi2Pd
beta-Bi2Pd compound has been proposed as another example of a multi-gap
superconductor [Y. Imai et al., J. Phys. Soc. Jap. 81, 113708 (2012)]. Here, we
report on measurements of several important physical quantities capable to show
a presence of multiple energy gaps on our superconducting single crystals of
beta-Bi2Pd with the critical temperature Tc close to 5 K. The calorimetric
study via a sensitive ac technique shows a sharp anomaly at the superconducting
transition, however only a single energy gap is detected. Also other
characteristics inferred from calorimetric measurements as the field dependence
of the Sommerfeld coefficient and the temperature and angular dependence of the
upper critical magnetic field point unequivocally to standard single s-wave gap
superconductivity. The Hall-probe magnetometry provides the same result from
the analysis of the temperature dependence of the lower critical field. A
single-gapped BCS density of states is detected by the scanning tunneling
spectroscopy measurements. Then, the bulk as well as the surface sensitive
probes evidence a standard conventional superconductivity in this system where
the topologically protected surface states have been recently detected by ARPES
[M. Sakano et al., Nature Comm. 6, 8595 (2015)] .Comment: 7 pages, 4 figures, 1 tabl
The Role of Perceived In-group Moral Superiority in Reparative Intentions and Approach Motivation
Three studies examined how members of a national group react to in-group wrongdoings. We expected that perceived in-group moral superiority would lead to unwillingness to repair the aggression. We also expected that internal-focused emotions such as group-based guilt and group-based shame would predict specific, misdeed-related reparative intentions but not general approach motivation toward the victim groups. In Study 1, facing the in-group’s recent aggression, participants who believed that the Hungarians have been more moral throughout their history than members of other nations, used more exonerating cognitions, experienced less in-group critical emotions and showed less willingness to provide reparations for the members of the victim group. Study 2 and Study 3 confirmed most findings of Study 1. Perceived in-group moral superiority directly or indirectly reduced willingness to provide either general or specific reparations, while internally focused in-group critical emotions predicted specific misdeed-related reparative intentions but not general approach motivation. The role of emotional attachment to the in-group is considered
Effect of boron nutrition on nutrient uptake and fruit quality of tart cherry in Eastern Hungary
Effect of the foliar boron (B) application on nutrient uptake and fruit quality of tart cherry (Prunus cerasus L.) was investigatedfrom 2008 to 2009 on mature four favourite Hungarian tart cherry cultivars like ‘Oblacsinszka’, ‘Érdi bôtermô’, ‘Újfehértói fürtös’ and ‘Petri’.Tart cherry trees grown in Eastern Hungary (Újfehértó) on an acidic sandy soil with low B content. Trees were treated with B by foliarapplication (0.5% B) at full bloom and untreated with B served as a control. B sprays strongly affected on B content of inflorescences.However, B sprays had no consistent effect on summer leaf B status. In our experiment stronger year effect was observed at leaf B status thanflower B status. The effectiveness of early spring boron applications are limited and mostly affected the flower B status only. Moreover,treatments had inconsistent effect on studied fruit inner parameters. Monosaccharides, vitamin C and organic acid contents of sour cherrywere stronger affected by cultivars than applied treatments
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