Miracle-dz/UniFAR-FTUs huggingface dataset:
Highly Homogeneous 2D/3D Heterojunction Diodes by Pulsed Laser Deposition of MoS2 on Ion Implantation Doped 4H‐SiC

In this paper, 2D/3D heterojunction diodes have been fabricated by pulsed laser deposition (PLD) of MoS2 on 4H‐SiC(0001) surfaces with different doping levels, i.e., n− epitaxial doping (≈1016 cm−3) and n+ ion implantation doping (>1019 cm−3). After assessing the excellent thickness uniformity (≈3L‐MoS2) and conformal coverage of the PLD‐grown films by Raman mapping and transmission electron microscopy, the current injection across the heterojunctions is investigated by temperature‐dependent current–voltage characterization of the diodes and by nanoscale current mapping with conductive atomic force microscopy. A wide tunability of the transport properties is shown by the SiC surface doping, with highly rectifying behavior for the MoS2/n− SiC junction and a strongly enhanced current injection for MoS2/n+ SiC one. Thermionic emission is found the dominant mechanism ruling forward current in MoS2/n− SiC diodes, with an effective barrier ΦB = (1.04 ± 0.09) eV. Instead, the significantly lower effective barrier ΦB = (0.31 ± 0.01) eV and a temperature‐dependent ideality factor for MoS2/n+ SiC junctions is explained by thermionic‐field‐emission through the thin depletion region of n+ doped SiC. The scalability of PLD MoS2 deposition and the electronic transport tunability by implantation doping of SiC represents key steps for industrial development of MoS2/SiC devices.
A Review of the Research on the Evaluation Metrics for Automatic Grammatical Error Correction System

The evaluation of an automatic grammatical error correction system is an important content in the field of automatic grammatical error correction. This paper summarizes the technical routes of the four most representative evaluation metrics of the automatic grammatical error correction systems. Firstly, it introduces the characteristics and composition of each metric, then summarizes its defects, and finally puts forward some suggestions for the future development of the metrics. This paper holds that the application of natural language processing technology should be strengthened in the future development of evaluation metrics.
A Compact Self-Hexaplexing Antenna Implemented on Substrate-Integrated Rectangular Cavity for Hexa-Band Applications

This brief introduces a novel architecture of a compact self-hexaplexing antenna (SHA) implemented on a substrate-integrated rectangular cavity (SIRC) for hexa-band applications. The proposed SHA is configured by using an SIRC resonator, two Pi-shaped slots (PSSs), and six <inline-formula> <tex-math notation="LaTeX">$50\Omega $ </tex-math></inline-formula> microstrip feedlines. The PSSs are connected back-to-back and loaded on top of the SIRC resonator to produce six patch radiators (PRs). The PRs are excited by <inline-formula> <tex-math notation="LaTeX">$50\Omega $ </tex-math></inline-formula> feedlines to radiate at six operating bands with self-multiplexing characteristics. The operating bands are tunable. A particular band can be adjusted independently based on the system requirement without altering the other operating bands. A comprehensive parametric study is carried out to allow a suitable band tunability, high isolation, and matching at the ports. For validation, an SIRC-based SHA radiating at 2.29, 2.96, 4.3, 5.0, 5.61, and 6.18 GHz is fabricated and experimentally demonstrated. The proposed SHA allows us to achieve a compact size of <inline-formula> <tex-math notation="LaTeX">$0.173\lambda _{g}^{2}$ </tex-math></inline-formula>, which is the smallest among the self-quadruplexing antennas and self-multiplexing antennas reported in the literature thus far. Additionally, it exhibits high isolation of 27 dB, hexa-band operation, a tunability range from 2.2 GHz to 8 GHz, along with measured gains greater than 3.73 dBi.
Space-time diagrammatics

We introduce a new class of two-dimensional diagrams, the projection diagrams, as a tool to visualize the global structure of space-times. We construct the diagrams for several metrics of interest, including the Kerr-Newman-(anti)de Sitter family, with or without cosmological constant, and the Emparan-Reall black rings.
Stability of linear systems with time-varying delays: an Lyapunov functional approach

A new stability criterion for linear systems with multiple time-varying delays is established by employing the method of Lyapunov functional based on the Lyapunov-Krasovskii theorem. This criterion has only one positive definite tuning parameter matrix in two LMIs, one LMI is exactly the same as the stability criteria for the corresponding system without delay and the other restrict on influence of delay. It is analytically shown the presented result is less conservative than those proposed theorems and techniques in the literature recently. Examples are given to show the application of the established stability theorem.
The antioxidant activity of lemongrass leaves extract against fibroblasts oxidative stress

Objective : The purpose of this research is to assess the antioxidant activity of lemongrass leaves extract in terms of lowering ROS generation and its effect on the viability and proliferation of fibroblasts under oxidative stress. Material and Methods : The antioxidant activity was measured using the DPPH method and the ROS assay was carried out by fluorescent H2DCFDA staining. Viability and proliferation assays were performed using the Cell Counting Kit-8 (CCK-8) and was read at 450 nm using microplate reader. The groups were divided into 8, namely fibroblasts without treatment (comparison group), fibroblast induced by H 2 O 2 (negative control), fibroblast with H 2 O 2 then treated with ascorbic acid (positive control), and fibroblast with H 2 O 2 then treated with lemongrass leaves extract at various concentrations (10, 20, 30, 40, and 50 ppm). Results : The results showed that the antioxidant activity of lemongrass leaves extract had an IC 50 value of 64.17 ppm. ROS production were reduced by the LgLE of all concentrations if compared with negative control (p=0.819). LgLE can maintained the fibroblast viability with 10 ppm of LgLE was the most optimum concentration (p<0.05). LgLE can induced the proliferation of fibroblast, with the most effective was at 24 h of observation (p<0.05). Conclusion : Lemongrass leaves extract has a strong antioxidant activity that can reduce oxidative stress and increase the viability and proliferation of fibroblasts with the optimum concentration is at 10 ppm.
Radiative efficiency of hot accretion flows

Over the past few years, our understanding of hot accretion flows has been improved significantly by two findings: (i) only a small fraction of the accretion flow available at the outer boundary can finally fall on to the black hole, while most of it is lost in the outflow; (ii) electrons can directly receive a large fraction of the viscously dissipated energy in the accretion flow (i. e. delta similar to 0.1-0.5). The radiative efficiency of the hot accretion flow when these two findings are taken into account has not yet been systematically studied, and this is the subject of our paper. We consider two regimes of the hot accretion model: advection-dominated accretion flows that lie in the regime of the low accretion rate, less than or similar to 10 alpha L-2(Edd)/c(2), and the luminous hot accretion flows (LHAFs) that lie above this accretion rate. For the LHAFs, we assume that the accretion flow has a two-phase structure above a certain accretion rate, and we adopt a simplification in our calculation of the dynamics. Our results indicate that the radiative efficiency of hot accretion flow increases with the accretion rate and that it is greatly enhanced by the direct viscous heating to electrons, compared to the previous case of delta << 1. When the accretion rate is high, the radiative efficiency of the hot accretion flow is comparable to that of a standard thin disc. We present fitting formulae of radiative efficiency as a function of accretion rate for various values of delta.
Grating Lobe Suppression for Wideband Large-Spacing Beam Scanning Array Using Subarray Null Adjustable Method

In this letter, a subarray null adjustable method is proposed to solve the grating lobe problem for wideband large-spacing beam scanning arrays. With the reshaped subarray by this method, large null depths of the pattern are formed to align with the grating lobe regions. The proposed reflective phase shifter loaded four varactors adjusts these nulls continuously, accurately and flexibly. Then, a wide-angle coverage of continuous nulls sufficiently suppress grating lobes in the whole bandwith. A two-element subarray with the bandwidth of 40% (2.8–4.2 GHz) is introduced, and an 8 × 4 planar array formed by this subarray is fabricated and measured as the verification prototype. Finally, the proposed planar beam scanning array realizes grating-lobe-free scanning of ±45° in the yoz-plane (with the array spacing of one wavelength at the highest frequency) and ±53° in the xoz-plane over the entire wideband range, respectively.
Feedback Regulated Turbulence, Magnetic Fields, and Star Formation Rates in Galactic Disks

Abstract We use three-dimensional magnetohydrodynamic (MHD) simulations to investigate the quasi-equilibrium states of galactic disks regulated by star formation feedback. We incorporate effects from massive-star feedback via time-varying heating rates and supernova (SN) explosions. We find that the disks in our simulations rapidly approach a quasi-steady state that satisfies vertical dynamical equilibrium. The star formation rate (SFR) surface density self-adjusts to provide the total momentum flux (pressure) in the vertical direction that matches the weight of the gas. We quantify feedback efficiency by measuring feedback yields, η c ≡ P c /ΣSFR (in suitable units), for each pressure component. The turbulent and thermal feedback yields are the same for HD and MHD simulations, ηth ~ 1 and ηturb ~ 4, consistent with the theoretical expectations. In MHD simulations, turbulent magnetic fields are rapidly generated by turbulence, and saturate at a level corresponding to ηmag,t ~ 1. The presence of magnetic fields enhances the total feedback yield and therefore reduces the SFR, since the same vertical support can be supplied at a smaller SFR. We suggest further numerical calibrations and observational tests in terms of the feedback yields.
Continuous Fixed-Time Fault-Tolerant Formation Control for Heterogeneous Multiagent Systems Under Fixed and Switching Topologies

This article proposes a novel continuous fixed-time fault-tolerant formation control framework for heterogeneous multiagent systems (HMASs) involving unmanned aerial vehicles (UAVs) and unmanned ground vehicles (UGVs) with actuator faults and model uncertainties under fixed and switching topologies. Firstly, to estimate the information of actuator faults and uncertainties for each follower, a fixed-time observer is constructed. Then, an integral fixed-time sliding mode surface is designed such that the merits of high robustness, exact transient response and fixed-time convergence can be achieved. Subsequently, based on the integration of disturbance observer, high-order sliding mode and backstepping technologies, distributed and decentralized continuous fixed-time formation tracking control schemes under actuator faults are developed of the HMASs in the X-Y axis and Z axis, respectively. The proposed algorithm can not only handle time-varying formation in a timely manner, but also provide continuous control action under fixed and switching topologies. It is theoretically proved that the designed protocol can realize the expected fixed-time formation missions by employing the Lyapunov stability theorem. Finally, simulation results verify the effectiveness of the designed fixed-time control algorithm.
Liparismacrosepala (Orchidaceae), a new species from southwest China with its phylogenetic position

﻿Abstract A new orchid species, Liparismacrosepala, is illustrated and described from Yunnan Province, China, based on morphological and molecular analyses. This plant is characterised by the ovoid-fusiform, slightly compressed pseudobulbs with 4 or 5 leaves with slightly crisped margins on their apical half, dorsal sepal heart-shaped, lip with a bituberculate basal callus and a thickened folded lateral lobe on each side, centrally with one cavity with slightly raised margins, the column with a single pair of broadly triangular, obtuse wings. Maximum Likelihood and Bayesian Inference analyses of combined nrITS and plastid matK DNA sequences place this species in section Cestichis.
Electronic properties of 8 − Pmmn borophene

First-principles calculations on monolayer 8-{\it Pmmn} borophene are reported to reveal unprecedented electronic properties in a two-dimensional material. Based on a Born effective charge analysis, 8-{\it Pmmn} borophene is the first single-element based monolayered material exhibiting two sublattices with substantial ionic features. The observed Dirac cones are actually formed by the p$_z$ orbitals of one of the inequivalent sublattices composed of uniquely four atoms, yielding an underlying hexagonal network topologically equivalent to distorted graphene. A significant physical outcome of this effect includes the possibility of converting metallic 8-{\it Pmmn} borophene into an indirect band gap semiconductor by means of external shear stress. The stability of the strained structures are supported by a phonon frequency analysis. The Dirac cones are sensitive to the formation of vacancies only in the inequivalent sublattice electronically active at the Fermi level.
Quantum Optical Effective-Medium Theory for Layered Metamaterials at Any Angle of Incidence

The quantum optics of metamaterials starts with the question of whether the same effective-medium theories apply as in classical optics. In general, the answer is negative. For active plasmonics but also for some passive metamaterials, we show that an additional effective-medium parameter is indispensable besides the effective index, namely, the effective noise-photon distribution. Only with the extra parameter can one predict how well the quantumness of states of light is preserved in the metamaterial. The fact that the effective index alone is not always sufficient and that one additional effective parameter suffices in the quantum optics of metamaterials is both of fundamental and practical interest. Here, from a Lagrangian description of the quantum electrodynamics of media with both linear gain and loss, we compute the effective noise-photon distribution for quantum light propagation in arbitrary directions in layered metamaterials, thereby detailing and generalizing our previous work. The effective index with its direction and polarization dependence is the same as in classical effective-medium theories. As our main result, we derive both for passive and for active media how the value of the effective noise-photon distribution too depends on the polarization and propagation directions of the light. Interestingly, for s-polarized light incident on passive metamaterials, the noise-photon distribution reduces to a thermal distribution, but for p-polarized light it does not. We illustrate the robustness of our quantum optical effective-medium theory by accurate predictions both for power spectra and for balanced homodyne detection of output quantum states of the metamaterial.
The Auto-Correlation Function Aided Sparse Support Matrix Machine for EEG-Based Fatigue Detection

Due to support vector machine (SVM) methods generally vectorizing the input matrix and destroying the location dependence characteristic of EEG signals, the support matrix machine (SMM) methods have been presented to incorporate input signal with its location information into the input data matrix and to perform the classification algorithm. In this brief, we investigate an auto-correlation function based sparse support matrix machine (ACF-SSMM) algorithm to optimize and classify the EEG fatigue signals. The main contents include: 1) to input a matrix EEG signal with location information and compress the redundant features by using the sparse principle; 2) to extend the input matrix by adding data through an ACF transform, which takes into account information containing the previous/current instants, to accurately express the memory dynamics of the EEG signals; 3) to perform multiple similar classification algorithms on the EEG fatigue dataset (SEED-VIG dataset) to verify effectiveness of the presented ACF-SSMM algorithm in EEG-based fatigue detection. The experiments get better results, and show the effectiveness of the proposed algorithm.
EXPLORING THE NATURE OF THE GALACTIC CENTER γ-RAY SOURCE WITH THE CHERENKOV TELESCOPE ARRAY

Observations from multiple γ-ray telescopes have uncovered a high-energy γ-ray source spatially coincident with the Galactic center. Recently, a compelling model for the broadband γ-ray emission has been formulated, which posits that high-energy protons emanating from Sgr A* could produce γ-rays through π0 decays resulting from inelastic collisions with the traversed interstellar gas in the region. Models of the gas distribution in the Galactic center region imply that the resulting γ-ray morphology would be observed as a point source with all current telescopes, but that the upcoming Cherenkov Telescope Array (CTA) may be able to detect an extended emission profile with an unmistakable morphology. Here, we critically evaluate this claim, employing a three-dimensional gas distribution model and a detailed Monte Carlo simulation, and using the anticipated effective area and angular resolution of CTA. We find that the impressive angular resolution of CTA will be key to test hadronic emission models conclusively against, for example, point source or dark matter annihilation scenarios. We comment on the relevance of this result for searches for dark matter annihilation in the Galactic center region.
Resilienz nach der Flucht: Perspektiven von Geflüchteten und unterstützenden Praxisakteur*innen

Zusammenfassung Studienziel Die Studie beabsichtigt, die Perspektiven auf Resilienz nach der Flucht von Geflüchteten und von unterstützenden Praxisakteur*innen zu identifizieren (Ziel 1) und die Perspektiven beider Gruppen zueinander in Beziehung zu setzen (Ziel 2), um die inhaltliche Tiefe des Verständnisses von Postfluchtresilienz zu erweitern und Erkenntnisse über Beziehungen zwischen Praxisakteur*innen und Geflüchteten bereitzustellen. Methodik Drei semistrukturierte, leitfadengestützte Fokusgruppen mit Geflüchteten (N=9) und Praxisakteur*innen (N=13) zur Erfassung der Perspektiven beider Gruppen auf Resilienz nach der Flucht wurden auf Deutsch durchgeführt. Sie wurden iterativ nach Constructionist Grounded Theory ausgewertet. Ergebnisse Geflüchtete und Praxisakteur*innen berichten Belastungsfaktoren Unsicherheit und Begrenzung, Adaptionsprozesse Gemeinschaftlichkeit und Anstrengung sowie die Adaptionsziele Stabilität, Verbundenheit und positive Emotionalität (Ziel 1). Die Aussagen von Geflüchteten und unterstützenden Praxisakteur*innen zu Resilienz nach der Flucht stimmen inhaltlich stark überein und ergänzen sich gegenseitig. Geflüchtete berichten individualisierter und spezifischer als Praxisakteur*innen (Ziel 2). Diskussion Die Aspekte der Resilienz, die Geflüchtete und unterstützende Praxisakteur*innen nennen, replizieren Ergebnisse vorhergehender qualitativer Studien zu Postfluchtresilienz, welche mit Geflüchteten durchgeführt wurden. Sowohl die Belastung, adäquate Adaptionsmöglichkeiten vor Ort z.T. nicht zu kennen, als auch Versuche, Resilienz-förderliche Bedingungen zu schaffen, könnten spezifisch für die Resilienz von Geflüchteten sein. Die inhaltlichen Übereinstimmungen zwischen Geflüchteten und Praxisakteur*innen könnten durch Erfahrungen der Praxisakteur*innen im Rahmen von Unterstützungsprozessen oder durch ähnliche Lebenserfahrungen der Praxisakteur*innen bedingt sein. Die weniger individualisierte Herangehensweise an Postfluchtresilienz der Praxisakteur*innen könnte durch ein höheres Abstraktionsniveau, Rollenerwartungen oder Umgang mit emotionaler Belastung verursacht sein. Schlussfolgerung Die Ergebnisse der Studie deuten darauf hin, dass die Resilienz Geflüchteter durch universelle und populationsspezifische Aspekte charakterisiert ist. Dass Praxisakteur*innen, die Geflüchtete unterstützen und Geflüchtete inhaltlich bezüglich der Resilienz nach der Flucht übereinstimmen, validiert die Ergebnisse bisheriger qualitativer Studien zu Resilienz nach der Flucht. Die Studie ermittelte darüber hinaus unterschiedliche Herangehensweisen von Geflüchteten und Praxisakteur*innen an Postfluchtresilienz, deren Verursachung weiterer Forschung bedarf.
THE METAL-ENRICHED OUTER DISK OF NGC 2915

We present optical emission-line spectra for outlying H ii regions in the extended neutral gas disk surrounding the blue compact dwarf galaxy NGC 2915. Using a combination of strong-line R23 and direct oxygen abundance measurements, we report a flat, possibly increasing, metallicity gradient out to 1.2 times the Holmberg radius. We find the outer disk of NGC 2915 to be enriched to a metallicity of 0.4 Z☉. An analysis of the metal yields shows that the outer disk of NGC 2915 is overabundant for its gas fraction, while the central star-forming core is similarly underabundant for its gas fraction. Star formation rates derived from very deep ∼14 ks GALEX FUV exposures indicate that the low level of star formation observed at large radii is not sufficient to have produced the measured oxygen abundances at these galactocentric distances. We consider three plausible mechanisms that may explain the metal-enriched outer gaseous disk of NGC 2915: radial redistribution of centrally generated metals, strong galactic winds with subsequent fallback, and galaxy accretion. Our results have implications for the physical origin of the mass–metallicity relation for gas-rich dwarf galaxies.
Inelastic x-ray scattering by electronic excitations under high pressure

Investigating electronic structure and excitations under extreme conditions gives access to a rich variety of phenomena. High pressure typically induces behavior such as magnetic collapse and the insulator-metal transition in 3d transition metals compounds, valence fluctuations or Kondo-like characteristics in $f$-electron systems, and coordination and bonding changes in molecular solids and glasses. This article reviews research concerning electronic excitations in materials under extreme conditions using inelastic x-ray scattering (IXS). IXS is a spectroscopic probe of choice for this study because of its chemical and orbital selectivity and the richness of information it provides. Being an all-photon technique, IXS has a penetration depth compatible with high pressure requirements. Electronic transitions under pressure in 3d transition metals compounds and $f$-electron systems, most of them strongly correlated, are reviewed. Implications for geophysics are mentioned. Since the incident X-ray energy can easily be tuned to absorption edges, resonant IXS, often employed, is discussed at length. Finally studies involving local structure changes and electronic transitions under pressure in materials containing light elements are briefly reviewed.