586 research outputs found
Disordered Fe vacancies and superconductivity in potassium-intercalated iron selenide (K2-xFe4+ySe5)
The parent compound of an unconventional superconductor must contain unusual
correlated electronic and magnetic properties of its own. In the high-Tc
potassium intercalated FeSe, there has been significant debate regarding what
the exact parent compound is. Our studies unambiguously show that the
Fe-vacancy ordered K2Fe4Se5 is the magnetic, Mott insulating parent compound of
the superconducting state. Non-superconducting K2Fe4Se5 becomes a
superconductor after high temperature annealing, and the overall picture
indicates that superconductivity in K2-xFe4+ySe5 originates from the Fe-vacancy
order to disorder transition. Thus, the long pending question whether magnetic
and superconducting state are competing or cooperating for cuprate
superconductors may also apply to the Fe-chalcogenide superconductors. It is
believed that the iron selenides and related compounds will provide essential
information to understand the origin of superconductivity in the iron-based
superconductors, and possibly to the superconducting cuprates
Mediating role of resilience in the relationships of physical activity and mindful self-awareness with peace of mind among college students
Abstract Peace of mind (PoM) is an index of mental health in Asian culture and emphasizes low arousal, happiness, harmony, and an internal state of peacefulness. While previous studies have found that mindful self-awareness can contribute to PoM, regular physical activity (PA) is also an important factor contributing to one’s PoM due to its function in promoting one's resilience. The study aims to investigate a hypothetical model that assumes PA is associated with resilience while controlling for mindful self-awareness, contributing to PoM. The PoM scale, Connor-Davidson Resilience Scale, Chinese translation of Mindful Attention Awareness Scale, and PA self-report questionnaire were used. A path analysis was applied to test the association between these variables and the mediating role of resilience. A total of 436 students from a university in Taiwan were recruited; the mean age was 20.87, with 46.3% female and 73.6% engaging in over 150 min/week of moderate PA. Gender and age negatively correlated with PA. After controlling for age and gender, there was no direct effect of physical activity on PoM; both mindful self-awareness and PA predict resilience, which in turn predicts PoM, suggesting that both cognitive (i.e., mindful self-awareness) and PA are important to cultivate resilience and thus PoM
Selection for Replicases in Protocells
PMCID: PMC3649988This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
Tellurium substitution effect on superconductivity of the alpha-phase Iron Selenide
We have carried out a systematic study of the PbO-type compound
FeSe_{1-x}Te_x (x = 0~1), where Te substitution effect on superconductivity is
investigated. It is found that superconducting transition temperature reaches a
maximum of Tc=15.2K at about 50% Te substitution. The pressure-enhanced Tc of
FeSe0.5Te0.5 is more than 10 times larger than that of FeSe. Interestingly,
FeTe is no longer superconducting. A low temperature structural distortion
changes FeTe from triclinic symmetry to orthorhombic symmetry. We believe that
this structural change breaks the magnetic symmetry and suppresses
superconductivity in FeTe.Comment: Some typing errors are corrected; we take out one figures, now the
paper has 14 pages, 5 figure
Cesarean section may increase the risk of both overweight and obesity in preschool children
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