92 research outputs found
Real-Time Gate Reassignment Based on Flight Delay Feature in Hub Airport
Appropriate gate reassignment is crucially important in efficiency improvement on airport sources and service quality of travelers. The paper divides delay flight into certain delay time flight and uncertain delay time flight based on flight delay feature. The main objective functions of model are to minimize the disturbance led by gate reassignment in the case of certain delay time flight and uncertain delay time flight, respectively. Another objective function of model is to build penalty function when the gate reassignment of certain delay time flight influences uncertain delay time flight. Ant colony algorithm (ACO) is presented to simulate and verify the effectiveness of the model. The comparison between simulation result and artificial assignment shows that the result coming from ACO is obvious prior to the result coming from artificial assignment. The maximum disturbance of gate assignment is decreased by 13.64%, and the operation time of ACO is 118âs. The results show that the strategy of gate reassignment is feasible and effective
Self-Dual Vortices in the Fractional Quantum Hall System
Based on the -mapping theory, we obtain an exact Bogomol'nyi self-dual
equation with a topological term, which is ignored in traditional self-dual
equation, in the fractional quantum Hall system. It is revealed that there
exist self-dual vortices in the system. We investigate the inner topological
structure of the self-dual vortices and show that the topological charges of
the vortices are quantized by Hopf indices and Brouwer degrees. Furthermore, we
study the branch processes in detail. The vortices are found generating or
annihilating at the limit points and encountering, splitting or merging at the
bifurcation points of the vector field .Comment: 13 pages 10 figures. accepted by IJMP
An alternative pathway for repair of deaminated bases in DNA triggered by archaeal NucS endonuclease
International audienc
A facile one-pot synthesis of CaO/CuO hollow microspheres featuring highly porous shells for enhanced CO2 capture in combined Ca-Cu looping process via a template-free synthesis approach
The preparation of bifunctional CaO/CuO composites with high performance is essential for the development of the combined CaâCu looping process, in which the exothermic reduction of CuO with methane is used in situ to provide the heat required to calcine CaCO3. However, the rapid decline in CO2 uptake of CaO/CuO composites remains an important problem to be solved, despite their excellent redox characteristic. Herein we report a facile one-pot template-free synthesis approach to yield CaO/CuO hollow microspheres, aimed at enhancing the CO2 capture performance of CaO/CuO composites. CaO/CuO hollow microspheres feature highly porous shells and a homogeneous elemental distribution, and demonstrate significantly enhanced CO2 capture performance. After ten repeated cycles in a fixed-bed reactor, the CO2 uptake capacity of the best-performing CaO/CuO hollow microspheres exceeded that of the reference materials, i.e., CaO/CuO composites synthesized via wet mixing or a co-precipitation method, by 222% and 114%, respectively. Moreover, from cycle number eight onwards, the CO2 uptake was very stable over the tested 20 cycles, suggesting good cyclic stability of CaO/CuO hollow microspheres. Oxidation was always fast with O2 uptake capacities greater than 0.13 gO2 gmaterialâ1. On the basis of N2 adsorption, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) characterizations, the significantly enhanced CO2 capture performance of the CaO/CuO hollow microspheres resulted from the unique hollow microsphere structure with highly porous shells, which were retained throughout the cyclic operations
Time correlation of success recanalization for endovascular recanalization of medically refractory non-acute intracranial arterial occlusions
Background and purposeThe management of patients with symptomatic non-acute atherosclerotic intracranial artery occlusion (sNAA-ICAO), which is a special subset with high morbidity and a high probability of recurrent serious ischemic events despite standard medical therapy, has been clinically challenging. A number of small-sample clinical studies have discussed endovascular recanalization for sNAA-ICAO and the lack of a uniform standard of operation time. The purpose of this study was to investigate the time correlation of successful recanalization.MethodsFrom January 2013 to August 2021, 69 consecutive patients who underwent endovascular recanalization for sNAA-ICAO were analyzed retrospectively in the First Affiliated Hospital of Harbin Medical University. The technical success rate, periprocedural complications, and rate of TIA/ischemic stroke during follow-up were evaluated.ResultsThe overall technical success rate was 73.91% (51/69), and the rate of perioperative complications was 37.68% (26/69). The percentage of patients with perioperative symptoms was 27.53% (19/69). The rate of serious symptomatic perioperative complications was 8.70% (6/69). After adjusting for age, sex, and BMI, the effect of the time from the last symptom to operation on successful recanalization was 0.42 (IQR, 0.20, 0.88, Pâ=â0.021), before the inflection point (51 days).ConclusionsEndovascular recanalization for sNAA-ICAO is technically feasible in reasonably selected patients. The perioperative safety is within the acceptable range. Before 51 days, the last symptoms to operation time, for every 10 days of delay, the probability of successful recanalization is reduced by 57%
Phonon promoted charge density wave in topological kagome metal ScVSn
Charge density wave (CDW) orders in vanadium-based kagome metals have
recently received tremendous attention due to their unique properties and
intricate interplay with exotic correlated phenomena, topological and
symmetry-breaking states. However, the origin of the CDW order remains a topic
of debate. The discovery of ScVSn, a vanadium-based bilayer kagome
metal exhibiting an in-plane x 30
CDW order with time-reversal symmetry breaking, provides a novel platform to
explore the underlying mechanism behind the unconventional CDW. Here, we
combine high-resolution angle-resolved photoemission spectroscopy, Raman
scattering measurements and density functional theory to investigate the
electronic structures and phonon modes of ScVSn and their evolution
with temperature. We identify topologically nontrivial Dirac surface states and
multiple van Hove singularities (VHSs) in the vicinity of the Fermi level, with
one VHS near the K point exhibiting nesting wave vectors in proximity to the
x 30 CDW wave vector. Additionally,
Raman measurements indicate a strong intrinsic electron-phonon coupling in
ScVSn, as evidenced by the presence of a two-phonon mode and a
large frequency amplitude mode. Our findings highlight the fundamental role of
lattice degrees of freedom in promoting the CDW in ScVSn and
provide important insights into the fascinating correlation phenomena observed
in kagome metals
Orbital Origin of Extremely Anisotropic Superconducting Gap in Nematic Phase of FeSe Superconductor
The iron-based superconductors are characterized by multiple-orbital physics
where all the five Fe 3 orbitals get involved. The multiple-orbital nature
gives rise to various novel phenomena like orbital-selective Mott transition,
nematicity and orbital fluctuation that provide a new route for realizing
superconductivity. The complexity of multiple-orbital also asks to disentangle
the relationship between orbital, spin and nematicity, and to identify dominant
orbital ingredients that dictate superconductivity. The bulk FeSe
superconductor provides an ideal platform to address these issues because of
its simple crystal structure and unique coexistence of superconductivity and
nematicity. However, the orbital nature of the low energy electronic
excitations and its relation to the superconducting gap remain controversial.
Here we report direct observation of highly anisotropic Fermi surface and
extremely anisotropic superconducting gap in the nematic state of FeSe
superconductor by high resolution laser-based angle-resolved photoemission
measurements. We find that the low energy excitations of the entire hole pocket
at the Brillouin zone center are dominated by the single orbital. The
superconducting gap exhibits an anti-correlation relation with the
spectral weight near the Fermi level, i.e., the gap size minimum (maximum)
corresponds to the maximum (minimum) of the spectral weight along the
Fermi surface. These observations provide new insights in understanding the
orbital origin of the extremely anisotropic superconducting gap in FeSe
superconductor and the relation between nematicity and superconductivity in the
iron-based superconductors.Comment: 19 pages, 4 figure
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