bluuebunny/crossref_metadata_2025_split huggingface dataset:
Surface thermodynamics of yttrium titanate pyrochlore nanomaterials
Authors: Reece Margaret E. , Li Jiahong , Strzelecki Andrew C. , Wen Juan , Zhang Qiang , Guo Xiaofeng 
Published: February 2024

Critical particle size can be determined with known surface energy. The surface enthalpy of yttrium titanate pyrochlores was determined to be 4.07 ± 0.32 J m−2 by calorimetry, and the lower limit of critical particle size for this is around 5.0 nm.
Inhibition of the histone methyltransferase EZH2 induces vascular stiffness
Authors: Ibarrola Jaime , Xiang Rachel R. , Sun Zhe , Lu Qing , Hill Michael A. , Jaffe Iris Z. 
Published: February 2024

Abstract
Vascular stiffness increases with aging, obesity and hypertension and predicts cardiovascular risk. The levels of histone H3-lysine-27 methylation (H3K27me) and the histone methyltransferase EZH2 both decrease in aging vessels, driving vascular stiffness. The impact of EZH2 inhibitors on vascular stiffness is unknown. We tested the hypothesis that the EZH2 inhibitor GSK126, currently in development for cancer treatment, increases vascular stiffness and explored underlying molecular mechanisms. Young (3 month) and middle-aged (12 month) male mice were treated with GSK126 for 1–2 months and primary human aortic smooth muscle cells (HASMCs) from young male and female donors were treated with GSK126 for 24–48 h. Stiffness was measured in vivo by pulse wave velocity and in vitro by atomic force microscopy (AFM) and vascular structure was quantified histologically. Extracellular matrix proteins were studied by qRT-PCR, immunoblotting, zymography and chromatin immunoprecipitation. GSK126 treatment decreased H3K27 methylation (H3K27me) and increased acetylation (H3K27ac) in mouse vessels and in HASMCs. In GSK126-treated mice, aortic stiffness increased without changes in vascular fibrosis. EZH2 inhibition enhanced elastin fiber degradation and matrix metalloprotease-2 (MMP2) expression. In HASMCs, GSK126 treatment increased synthetic phenotype markers and intrinsic HASMCs stiffness by AFM with altered cytoskeletal structure and increased nuclear actin staining. GSK126 also increased MMP2 protein expression, activity and enrichment of H3K27ac at the MMP2 promoter in HASMCs. GSK126 causes vascular stiffening, inducing MMP2 activity, elastin degradation, and modulation of SMC phenotype and cytoskeletal stiffness. These findings suggest that EZH2 inhibitors used to treat cancer could negatively impact the vasculature by enhancing stiffness and merits examination in human trials.
A novel myocarditis detection combining deep reinforcement learning and an improved differential evolution algorithm
Authors: Yang Jing , Sadiq Touseef , Xiong Jiale , Awais Muhammad , Aslam Bhatti Uzair , Alizadehsani Roohallah , Gorriz Juan Manuel 
Published: February 2024

AbstractMyocarditis is a serious cardiovascular ailment that can lead to severe consequences if not promptly treated. It is triggered by viral infections and presents symptoms such as chest pain and heart dysfunction. Early detection is crucial for successful treatment, and cardiac magnetic resonance imaging (CMR) is a valuable tool for identifying this condition. However, the detection of myocarditis using CMR images can be challenging due to low contrast, variable noise, and the presence of multiple high CMR slices per patient. To overcome these challenges, the approach proposed incorporates advanced techniques such as convolutional neural networks (CNNs), an improved differential evolution (DE) algorithm for pre‐training, and a reinforcement learning (RL)‐based model for training. Developing this method presented a significant challenge due to the imbalanced classification of the Z‐Alizadeh Sani myocarditis dataset from Omid Hospital in Tehran. To address this, the training process is framed as a sequential decision‐making process, where the agent receives higher rewards/penalties for correctly/incorrectly classifying the minority/majority class. Additionally, the authors suggest an enhanced DE algorithm to initiate the backpropagation (BP) process, overcoming the initialisation sensitivity issue of gradient‐based methods like back‐propagation during the training phase. The effectiveness of the proposed model in diagnosing myocarditis is demonstrated through experimental results based on standard performance metrics. Overall, this method shows promise in expediting the triage of CMR images for automatic screening, facilitating early detection and successful treatment of myocarditis.
Derived dynamic scheduling for belief propagation decoding of LDPC codes
Authors: Xu Xiaotian , Zhou Hua , Zhao Jiayi 
Published: February 2024

AbstractAmong numerous dynamic scheduling strategies for low‐density parity‐check codes, many of them are of high complexity due to repetitive computation and ordering of belief residuals. To address these challenges, two novel approaches are proposed: the derived informed variable‐to‐check residual belief propagation and the derived variable‐node and variable‐to‐check‐edge residual belief propagation for low‐density parity‐check codes. Simulation results show that the derived dynamic scheduling exhibits a substantial gain of approximately 0.15 dB in signal‐to‐noise ratio over the non‐derived one with considerably lower decoding complexity when targeting a bit‐error rate of 10−4.
Cooperative task allocation method for multi‐unmanned aerial vehicles based on the modified genetic algorithm
Authors: Tan Yifang , Zhou Chao , Qian Feng 
Published: February 2024

AbstractUnmanned aerial vehicles (UAVs) play a crucial role in various domains such as military, civil, industrial, and so on. However, the coordination and task allocation of multiple UAVs in engineering practices face numerous challenges. As the scale of battlefields expands, and the diversity of UAV missions and constraints increases, the existing task allocation methods suffer from issues such as a mismatch between theoretical models and real‐world applications, low task execution efficiency, and poor responsiveness in dynamic environments. To address these challenges, this paper proposes an improved genetic algorithm (GA)‐based approach for multi‐UAV cooperative task allocation. By collecting battlefield information, decomposing tasks, and considering UAV resource types, an optimization model for multi‐UAV cooperative task allocation is constructed. The proposed method, using an improved GA, generates a set of Pareto‐optimal task solutions for decision‐makers. Case studies demonstrate that this approach effectively enhances task execution efficiency and reduces the total flight distance cost of UAVs.
Understanding wind turbine power converter reliability under realistic wind conditions
Authors: Alsaadi Sermed , Crabtree Christopher J. , Matthews Peter C. , Shahbazi Mahmoud 
Published: February 2024

AbstractThe reliability of wind turbine power converters is crucial for analyzing wind energy project costs, and for estimating maintenance and downtime. The published literature in this field relies on evaluating the reliability effect of wind speed to estimate the converter lifetime. However, this paper demonstrates that wind turbulence intensity, which has not been widely considered in similar reliability analyses, shows a significant impact on converter lifetime. This paper uses 821 10‐min wind speed time series sampled at 1 Hz on the two most commonly deployed wind turbine converter topologies: the two‐level voltage source and the three‐level neutral point clamped. Electromechanical and thermal modelling, combined with statistical analysis shows that mean wind speed and turbulence intensity both impact the lifetime of both converter topologies. However, the paper estimates that the three‐level converter can operate 2.4 to 4.0 times longer than the two‐level converter depending on the operating wind speed and turbulence intensity.
Net saving improvement of capacitor banks in power distribution systems by increasing daily size switching number: A comparative result analysis by artificial intelligence
Authors: Sadeghian Omid , Safari Ashkan 
Published: February 2024

AbstractThis paper studies the effect of the number of switching (NOS) per day of capacitor banks on loss reduction in radial distribution systems. To this aim, the daytime (more precisely, 24 h) is divided into different numbers of time segments (equal to the same NOS) for capacitors’ size switching. The resulting non‐linear programming with discontinuous derivatives (called DNLP) model is solved subject to related constraints. The results reveal the impact of hourly switching of capacitor banks on further loss reduction (namely 118.4435, 83.7856, and 101.738 MWh for three IEEE systems) and higher net savings (i.e. k$5.6067, k$4.2772, and k$5.3542 for the same systems) of radial distribution systems compared to daily switching. Then, the hyper‐tuned Random Forest model is trained based on the IEEE 69‐bus network, fine‐tuned by the IEEE 10‐bus network, and fitted by the IEEE 33‐bus network to have an intelligent multi‐classification task with the highest accuracy. Numerical simulation, in both classic and intelligent parts, is presented to demonstrate the performance of DeepOptaCap. For the final step, DeepOptaCast is compared to other intelligent models of Light Gradient Boosting Method (LGBM), Decision Tree, and XGBoost, regarding KPIs of mean absolute percentage error, root mean squared percentage error, mean absolute error, root mean squared error, and coefficient of determination to demonstrate the model's superiority.
The influence of accretion bursts on methanol and water in massive young stellar objects
Authors: Guadarrama R. , Vorobyov E. I. , Rab Ch. , Güdel M. , Caratti o Garatti A. , Sobolev A. M. 
Published: February 2024

Context. The effect of accretion bursts on massive young stellar objects (MYSOs) represents a new research field in the study of young stars and their environment. The impact of such bursts on the disk and envelope has been observed and plays the role of a “smoking gun” providing information about the properties of the burst itself.
Aims. We aim to investigate the impact of an accretion burst on massive disks with different types of envelopes and to study the effects of an accretion burst on the temperature structure and the chemistry of the disk. We focus on water and methanol as chemical species for this paper.
Methods. The thermochemical code of ProDiMo (PROtoplanetary DIsk MOdel) is used to perform simulations of high-mass protoplanetary-disk models with different types of envelopes in the presence of an accretion burst. The models in question represent different evolutionary stages of protostellar objects. We calculated and show the chemical abundances in three phases of the simulation (pre-burst, burst, and post-burst).
Results. More heavily embedded disks show higher temperatures. The impact of the accretion burst is mainly characterized by the desorption of chemical species present in the disk and envelope from the dust grains to the gas phase. When the post-burst phase starts, the sublimated species freeze out again. The degree of sublimation depends strongly on the type of envelope the disk is embedded in. An accretion burst in more massive envelopes produces stronger desorption of the chemical species. However, our models show that the timescale for the chemistry to reach the pre-burst state is independent of the type of envelope.
Conclusions. The study shows that the disk’s temperature increases with a more massive envelope enclosing it. Thus, the chemistry of MYSOs in earlier stages of their evolution reacts stronger to an accretion burst than at later stages where the envelope has lost most of its mass or has been dissipated. The study of the impact of accretion bursts could also provide helpful theoretical context to the observation of methanol masers in massive disks.
Gamma-ray detection of newly discovered Ancora supernova remnant: G288.8–6.3
Authors: Burger-Scheidlin Christopher , Brose Robert , Mackey Jonathan , Filipović Miroslav D. , Goswami Pranjupriya , Guillen Enrique Mestre , de Oña Wilhelmi Emma , Sushch Iurii 
Published: February 2024

Context. The supernova remnant (SNR) G288.8–6.3 was recently discovered as a faint radio shell at high Galactic latitude using observations with the Australian Square Kilometre Array Pathfinder (ASKAP) in the Evolutionary Map of the Universe (EMU) survey.
Aims. We performed the first detailed investigation of the γ-ray emission from the G288.8–6.3 region, aiming to characterise the high-energy emission in the GeV regime from the newly discovered SNR, dubbed Ancora.
Methods. Fifteen years of Fermi-Large Area Telescope (LAT) data were analysed at energies between 400 MeV and 1 TeV, and the excess seen in the region was modelled using different spatial and spectral models.
Results. We detect spatially extended γ-ray emission coinciding with the radio SNR, with detection significance up to 8.8 σ. A radial disk spatial model in combination with a power-law spectral model with an energy flux of (4.80 ± 0.91) × 10−6 MeV cm−2 s−1, with the spectrum extending up to around 5 GeV was found to be the preferred model. Morphologically, hotspots seen above 1 GeV are well correlated with the bright western part of the radio shell. The emission is more likely to be of leptonic origin, given the estimated gas density in the region and the estimated distance and age of the SNR, but a hadronic scenario cannot be ruled out.
Conclusions. Ancora is the seventh confirmed SNR detected at high Galactic latitude with Fermi-LAT. The study of this new population of remnants can provide insights into the evolutionary aspects of SNRs and their properties, and further advance efforts of constraining the physics of particle diffusion and escape from SNRs into the Galaxy.
Optical identification and follow-up observations of SRGA J213151.5+491400
Authors: Balman Ş. , Khamitov I. , Kolbin A. , Çalışkan E. Aktekin , Bikmaev I. , Özdönmez A. , Burenin R. , Kılıç Y. , Esenoğlu H. H. , Yelkenci K. F. , Çamurdan D. Zengin , Gilfanov M. , Nasıroğlu I. , Sonbaş E. , Gabdeev M. , Irtuganov E. , Saygaç A. T. , Nikolaeva E. , Sakhibullin N. , Er H. , Sazonov N. S. S. , Medvedev P. , Güver T. , Fişek S. 
Published: February 2024

Context. The paper is comprised of optical identification and multiwavelength studies of a new X-ray source discovered by the Spectrum Roentgen-Gamma (SRG) observatory during the ART-XC survey and its follow-up optical and X-ray observations.
Aims. We aim to identify SRGA J213151.5+491400 in the optical wavelengths. We determine spectra and light curves in the optical high and low states to find periodicities in the light curves and resolve emission lines in the system using optical ground-based data. We intend to study the spectral and temporal X-ray characteristics of the new source using the SRG surveys in the high and low states and NICER data in the low state.
Methods. We present optical data from telescopes in Türkiye (RTT-150 and T100 at the TÜBİTAK National Observatory) and in Russia (6-m and 1-m at SAO RAS), together with the X-ray data obtained with ART-XC and eROSITA telescopes aboard SRG and the NICER observatory. Using the optical data, we performed astrometry, photometry, spectroscopy, and power spectral analysis of the optical time series. We present optical Doppler tomography along with X-ray data analysis producing light curves and spectra.
Results. We detected SRGA J213151.5+491400 in a high state in 2020 (17.9 mag) that decreased by about 3 mag into a low state (21 mag) in 2021. We find only one significant period using optical photometric time series analysis, which reveals the white dwarf spin (orbital) period to be 0.059710(1) days (85.982 min). The long slit spectroscopy in the high state yields a power-law continuum increasing towards the blue with a prominent He II line along with the Balmer line emissions with no cyclotron humps, which is consistent with a magnetic cataclysmic variable (MCV) nature. Doppler Tomography confirms the polar nature revealing ballistic stream accretion along with magnetic stream during the high state. These characteristics show that the new source is a polar-type MCV source. ART-XC detections yield an X-ray flux of (4.0−7.0) × 10−12 erg s−1 cm−2 in the high state. eROSITA detects a dominating hot plasma component (kTmax > 21 keV in the high state) declining to (4.0−6.0) × 10−13 erg s−1 cm−2 in 2021 (low state). The NICER data obtained in the low state reveal a two-pole accretor showing a soft X-ray component at (6−7)σ significance with a blackbody temperature of 15−18 eV. A soft X-ray component has never been detected for a polar in the low state before.
The intermediate neutron capture process
Authors: Choplin A. , Siess L. , Goriely S. , Martinet S. 
Published: February 2024

Context. The intermediate neutron capture process (i-process) can develop during proton ingestion events (PIE), potentially during the early stages of low-mass low-metallicity asymptotic giant branch (AGB) stars.
Aims. We examine the impact of overshoot mixing on the triggering and development of i-process nucleosynthesis in AGB stars of various initial masses and metallicities.
Methods. We computed AGB stellar models, with initial masses of 1, 2, 3, and 4 M⊙ and metallicities in the −2.5 ≤ [Fe/H] ≤ 0 range, using the stellar evolution code STAREVOL with a network of 1160 nuclei coupled to the transport equations. We considered different overshooting profiles below and above the thermal pulses, and below the convective envelope.
Results. The occurrence of PIEs is found to be primarily governed by the amount of overshooting at the top of pulse (ftop) and to increase with rising ftop. For ftop = 0, 0.02, 0.04, and 0.1, we find that 0%, 6%, 24%, and 86% of our 21 AGB models with −2 < [Fe/H] < 0 experience a PIE, respectively. Variations of the overshooting parameters during a PIE leads to a scatter on abundances of 0.5 − 1 dex on elements, with 36 < Z < 56; however, this barely impacts the production of elements with 56 < Z < 80, which therefore appear to be a reliable prediction of our models. Actinides are only produced if the overshooting at the top of pulse is small enough. We also find that PIEs leave a 13C-pocket at the bottom of the pulse that can give rise to an additional radiative s-process nucleosynthesis. In the case of the 2 M⊙ models with [Fe/H] = −1 and −0.5, it produces a noticeable mixed i + s chemical signature at the surface. Finally, the chemical abundance patterns of 22 observed r/s-stars candidates (18 dwarfs or giants and 4 post-AGB) with −2 < [Fe/H] < −1 are found to be in reasonable agreement with our AGB model predictions. The binary status of the dwarfs/giants being unclear, we suggest that these stars have acquired their chemical pattern either from the mass transfer of a now-extinct AGB companion or from an early generation AGB star that polluted the natal cloud.
Conclusions. The occurrence of PIEs and the development of i-process nucleosynthesis in AGB stars remains sensitive to the overshooting parametrization. A high (yet realistic) ftop value triggers PIEs at (almost) all metallicities. The existence of r/s-stars at [Fe/H] ≃ −1 is in favour of an i-process operating in AGB stars up to this metallicity. Stricter constraints from multi-dimensional hydrodynamical models on overshoot coefficients could deliver new insights into the contribution of AGB stars to heavy elements in the Universe.
Luminous characteristics of high-voltage blue mini-light-emitting diodes
Authors: Xu Xiongfei , Zheng Xi , Tong ChangDong , Li Minghua , Lu Yijun , Chen Zhong , Guo Weijie 
Published: February 2024

The luminous characteristics of flip-chip type high-voltage (HV) blue mini-light-emitting diodes (LEDs), which consist of three serially connected sub-mesas, have been investigated for the first time. The cryogenic electroluminescence below 100 K partially originates from localized excitons. As the driving current reaches 1 μA, the contributions of Shockley–Read–Hall nonradiative recombination and radiative recombination exhibit a remarkably inverse temperature dependence, while the contributions of Auger recombination and carrier leakage are relatively negligible. The mesa corresponding to the anode of the HV blue mini-LED exhibits the lowest temperature among the three sub-mesas due to its smaller thermal resistance. To minimize the temperature-induced shift in chromaticity coordinates, it is necessary to adjust the driving current based on the operating temperature.
Reversal of optical binding force on a plasmonic heterodimer with dipole–dipole type Fano resonance
Authors: Zhang Xiaoming , Xie Biao , Liu Jianping 
Published: February 2024

In the present work, we theoretically and numerically investigate the near field optical binding force on Au–Ag nanorod heterodimers, which can support the electrical dipole–dipole type Fano resonance, under a normally plane wave or polarized laser beam. The numerical results show that the optical binding force between the heterodimer can be reversed near the position of the Fano dip when the incident wave is polarized along the dimer axis, indicating an attractive to repulsive transition. Compared with the Au–Ag heterodimer, the Au and Ag homodimers with the same material show no repulsive binding force. Using the multipole decomposition method, we find that the sign of optical binding force is completely determined by the phase difference of the separated electric dipole plasmon modes excited in the different particles, which can be strongly affected by the wavelength of the incident wave. In addition, we demonstrate the effects of three geometrical parameters (including the length, radius, and gap of the heterodimer) on the Fano-mediated optical binding force in detail. Finally, the numerical results indicate that the reversal of attractive and repulsive forces can also be obtained when the heterodimer is illuminated with a laser beam. Our findings are important for not only a deep understanding of plasmonic-mediated optical binding force but also stable optical manipulation of the plasmonic particles.
Hybrid integrated tunable external cavity laser with sub-10 Hz intrinsic linewidth
Authors: Wu Yilin , Shao Shuai , Tang Liwei , Yang Sigang , Chen Hongwei , Chen Minghua 
Published: February 2024

In this work, a hybrid integrated tunable external cavity laser (ECL) with a sub-10 Hz intrinsic linewidth is demonstrated. In this hybrid ECL, two Si3N4-based subwavelength hole defect assisted microring resonators, acting as high-Q laser reflectors, are butt-coupled with a chip-scale semiconductor optical amplifier at the two edges, respectively. The experimental results show that the hybrid ECL achieves a sub-10 Hz intrinsic linewidth across a wavelength tuning range from 1525 to 1565 nm, featuring a record lowest value of 6.06 Hz. The demonstrated hybrid ECL opens up opportunities toward the applications of high-speed optical communications and high-resolution light detection and ranging.