203 research outputs found
Tilings of the sphere by congruent quadrilaterals II: edge combination with rational angles
Edge-to-edge tilings of the sphere by congruent quadrilaterals are completely
classified in a series of three papers. This second one applies the powerful
tool of trigonometric Diophantine equations to classify the case of
-quadrilaterals with all angles being rational degrees. There are
sporadic and infinite sequences of quadrilaterals admitting the -layer
earth map tilings together with their modifications, and sporadic
quadrilaterals admitting exceptional tilings. Among them only
quadrilaterals are convex. New interesting non-edge-to-edge triangular tilings
are obtained as a byproduct.Comment: 36 pages, 36 figures, 10 table
Uniaxial and hydrostatic pressure effects in alpha-RuCl3 single crystals via thermal-expansion measurements
We present high-resolution thermal-expansion and specific-heat measurements
of single crystalline alpha-RuCl3. An extremely hysteretic structural
transition expanding over 100 K is observed by thermal- expansion along both
crystallographic axes, which we attribute to a change of stacking sequence of
the RuCl3 layers. Three magnetic transitions are observed, which we link to the
different stacking sequences. Using our data and thermodynamic relations, we
derive the uniaxial and hydrostatic pressure derivatives of all three magnetic
transitions. Our results demonstrate that magnetic order should be totally
suppressed by very moderate pressures of 0.3 GPa to 0.9 GPa. Finally, we
discuss why our results differ from recent hydrostatic pressure measurements
and suggest a possible route to reaching the spin-liquid state in alpha-RuCl3.Comment: 6 pages, 3 figure
Real estate rental market: a 10-year bibliometricbased review
The real estate rental market (RERM) is considered to have an
important role in the entire real estate market. It refers to a property composed of land and its buildings, including the natural
resources that can be rented or leased. Previous researches show
that most developed countries have experienced the historical
process of passively renting, actively buying, and actively renting.
Moreover, academic interest in the impact of different sectors of
the RERM has been reviewed increasingly over the past decade.
However, previous studies provide limited insights into a comprehensive review of the RERM. Based on a 10-year database of 790
articles collected from the Web of Science, a comprehensive literature review is presented to discover the knowledge structure
of RERM using CiteSpace software. First, this study recognizes the
cluster of the articles, and discusses six major clusters in detail.
Next, this study has identified four research trends that emerged
during the past decade. To reveal the differences between the
studies in the United States (US), China and the United Kingdom
(UK), this study compares their publication scales and co-word
networks. Finally, this study suggests six meaningful future
research directions
Tilings of the sphere by congruent quadrilaterals III: edge combination with general angles
Edge-to-edge tilings of the sphere by congruent quadrilaterals are completely
classified in a series of three papers. This last one classifies the case of
-quadrilaterals with some irrational angle: there are a sequence of
-parameter families of quadrilaterals admitting -layer earth map tilings
together with their basic flip modifications under extra condition, and
sporadic quadrilaterals each admitting a special tiling. A summary of the full
classification is presented in the end.Comment: 29 pages, 22 figures, 12 tabl
Magnetic anisotropy in hole-doped superconducting Ba 0.67K 0.33Fe 2As2 probed by polarized inelastic neutron scattering
We use polarized inelastic neutron scattering (INS) to study spin excitations
of optimally hole-doped superconductor BaKFeAs
( K).
In the normal state, the imaginary part of the dynamic susceptibility,
, shows magnetic anisotropy for energies below
7 meV with c-axis polarized spin excitations larger than that of the
in-plane component. Upon entering into the superconducting state, previous
unpolarized INS experiments have shown that spin gaps at 5 and 0.75 meV
open at wave vectors and , respectively, with a
broad neutron spin resonance at meV. Our neutron polarization analysis
reveals that the large difference in spin gaps is purely due to different spin
gaps in the c-axis and in-plane polarized spin excitations, resulting resonance
with different energy widths for the c-axis and in-plane spin excitations. The
observation of spin anisotropy in both opitmally electron and hole-doped
BaFeAs is due to their proximity to the AF ordered BaFeAs where
spin anisotropy exists below .Comment: 5 pages, 4 figure
Expression and function of ATP-dependent potassium channels in zebrafish islet β-cells
ATP-sensitive potassium channels (K(ATP) channels) are critical nutrient sensors in many mammalian tissues. In the pancreas, K(ATP) channels are essential for coupling glucose metabolism to insulin secretion. While orthologous genes for many components of metabolism–secretion coupling in mammals are present in lower vertebrates, their expression, functionality and ultimate impact on body glucose homeostasis are unclear. In this paper, we demonstrate that zebrafish islet β-cells express functional K(ATP) channels of similar subunit composition, structure and metabolic sensitivity to their mammalian counterparts. We further show that pharmacological activation of native zebrafish K(ATP) using diazoxide, a specific K(ATP) channel opener, is sufficient to disturb glucose tolerance in adult zebrafish. That β-cell K(ATP) channel expression and function are conserved between zebrafish and mammals illustrates the evolutionary conservation of islet metabolic sensing from fish to humans, and lends relevance to the use of zebrafish to model islet glucose sensing and diseases of membrane excitability such as neonatal diabetes
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