bluuebunny/crossref_metadata_2025_split huggingface dataset:
Properties of flare events based on light curves from the TESS survey
Authors: Yang Zilu , Zhang Liyun , Meng Gang , Han Xianming L. , Misra Prabhakar , Yang Jiawei , Pi Qingfeng 
Published: October 2022

Aims. A stellar flare is a strong energy burst event. Understanding stellar flares is important for determining the properties of stellar magnetic activities. We aim to perform detailed statistical analyses on stellar flare characteristics in terms of the different stellar parameters using the light curves of the Transiting Exoplanet Survey Satellite (TESS) survey from July 2018 to October 2020.
Methods. By using repeated fitting to differentiate stellar background light curves from flare events, we precisely detected 60 810 flare events on 13 478 stars from sectors 1–30 of the TESS data and determined the flare parameters. After cross-matching our samples with the Gaia survey, we obtained more stellar parameters to determine the relationship between flare parameters and stellar parameters.
Results. The fraction of flaring stars decreases as stellar temperatures increase in the region of 2500–6500 K and stellar mass increases from 0.08 to 1.4 M⊙. The flare energies increase as the stellar temperature and the stellar mass decrease. There is a weak relationship between flare amplitude and Ro. We also confirm that M-type stars produce flares more frequently than F-, G-, and K-type stars. We find that the proportion of flaring stars increases from M0 to M5, and decreases from M5 to M7. We obtain a power-law index of 1.83 ± 0.15 for the cumulative flare frequency distribution. The index shows a decreasing trend from F- to K-type stars, and M-type stars rise for dwarf samples. The fraction of flaring stars decreases as the vertical absolute height increases in the range 0–200 pc but this fraction is stable in the range 200–800 pc. We find that eclipsing binary stars show more frequent flares than single stars.
Measuring competition between the great powers across Africa and Asia using a measure of relative dispersion in media coverage bias
Authors: Gooch Elizabeth , Goethe Stone , Sobrepena Nicholas , Eckstrand Eric 
Published: October 2022

AbstractSenior leaders in the US Department of Defense, as well as global affairs strategists and academics, have argued that China’s economic growth is associated with a dramatic increase in competition for resources and Chinese influence abroad. We aim to ascertain whether and where competition between great powers exists and to characterize China’s growing influence. Our main contribution is that we create a measure of competition among the United States, China, Russia, India, and France within African and Asian countries. We draw our data from a large media database that records news articles published since March 2015. We sum the quantity of articles published by local press agencies that discuss an international or regional powers’ engagement in an event located within the Asian or African countries’ borders, and we construct a measure of country-level competition among powers. To validate our country-level competition measure, we synthesize qualitative information from current government, think tanks, and academic documents on the presence and interests of foreign powers across subregions in Asia and Africa. From those narratives, we construct an additional subregional measure of competition. We compare our statistical country-level measure of competition to this narrative-based subregional measure of competition and find that they are correlated.
Large area multi-filamentary plasma source for large volume plasma device–upgrade
Authors: Sanyasi A. K. , Srivastava P. K. , Adhikari Ayan , Awasthi L. M. , Leuva P. , Santra P. , Doshi B. , Gupta M. K. , Sugandhi R. 
Published: October 2022

This paper discusses the salient features and plasma performance of the newly installed Large Area Multi-Filamentary Plasma Source (LAMPS) in large volume plasma device–upgrade. The plasma source is designed to exhibit a plasma electron density of ∼1018 m−3, low electron temperature (∼eV), and a uniform plasma cross section of 2.54 m2. The directly heated LAMPS emits accelerated primary energetic electrons when it is biased with a negative discharge voltage with respect to the anode. The hairpin shaped tungsten (W) filaments, each of diameter 0.5 mm and length 180 mm, are heated to a temperature of 2700 K by feeding ∼19.5A to each filament. The LAMPS consists of 162 numbers of filaments, and it has been successfully operated with a total investment of 50 kW of electrical power. The LAMPS as a laboratory plasma source is characterized by large operational life, ease of handling, better compatibility to high pressure conditions, and advantages over other contemporary plasma sources, viz., oxide coated cathodes, RF based sources, and helicon sources, when producing plasma over large cross sections and fill volumes. Pulsed argon plasma is produced with quiescence (δnene≪1%) using LAMPS for the duration of 50 ms and a reasonably good radial uniformity (Ln = 210 cm) is achieved. Good axial uniformity is also observed over the entire length of the device. Initial measurements on plasma parameters have yielded plasma density of ∼2×1017m−3 with existing set of filaments. A plasma density of ∼1018 m−3 is envisaged for larger thickness of filaments, such as 0.75 and 1.0 mm, with the existing plasma source assembly setup.
La posición de clíticos argumentales con complejos verbales en un corpus oral
Authors: Manjón-Cabeza Cruz Antonio 
Published: October 2022

Abstracta
En español los clíticos pronominales muestran la posibilidad de variación cuando acompañan a un complejo verbal, ya que pueden ir antepuestos o pospuestos. Esta posibilidad ha sido tratada desde enfoques formalistas, visiones diacrónicas y, en menor medida, con criterios sociolingüísticos. Desde esta última perspectiva contamos con aportaciones sobre el español canario (Troya & Pérez, 2011), venezolano (Navarro, 1990; Zabalegui, 2008), mexicano (Schwenter & Torres Cacoullos, 2014) y peninsular (Illamola & Vila, 2015). Son estudios con disparidad de alcance, corpus y criterios, por lo que es necesario el estudio en un corpus monolingüe que pueda ser replicado en otros lugares hispánicos.
Tras establecer algunas precisiones metodológicas previas que se derivan de la naturaleza de los datos del corpus, hemos hallado que, junto con los factores previamente señalados en estudios previos, son pertinentes otros más inusuales, como el semantismo verbal y la presencia del sujeto léxico. No obstante, la principal aportación de este trabajo es la comprobación de la influencia del factor social nivel de estudios, que se plasma en un patrón curvilíneo donde el grupo intermedio presenta porcentajes de posposición superiores a los otros grupos. Contribuyen especialmente a ese patrón las mujeres y los estratos de edad intermedios y mayores.
Direct object anaphora resolution in L1 English-L2 Spanish
Authors: García-Tejada Aída 
Published: October 2022

Abstract
This study investigates the written production of direct object (DO) anaphora in L2 Spanish by adult English
native speakers. It focuses on the use of clitics and full DPs in topic continuity, where highly salient topics are typically
recovered by clitics in native Spanish. A combination of pragmatic factors in subject anaphora resolution (referential ambiguity
and distance) and morphosyntactic factors in the acquisition of clitics (gender and animacy) was analyzed in 5 subcorpora from the
CEDEL2 (Corpus Escrito del Español L2). Following Learner Corpus Research methodology, 773 anaphoric DOs and
their antecedents were tagged across 150 texts (from low-intermediate to upper-advanced proficiency). Results showed that as
learner proficiency increases, the predominant anaphoric strategy shifts from redundant DP overuse to felicitous
pronominalization. Clitic avoidance is the general strategy intimately related to clitics’ morphosyntactic deficits at advanced
levels, but also to pragmatic principles supporting the Pragmatic Principles Violation Hypothesis (Lozano, 2016).
Epistemic stance in the climate change debate
Authors: Biri Ylva 
Published: October 2022

AbstractThis study analyses epistemic stance in social media climate change discussions, contributing to our understanding of how factuality and likelihood are evaluated in climate change discourse. Using a corpus of 1.2 million words, the paper compares the frequencies of epistemic stance in climate change sceptic and climate change proponent discourses on two social media platforms, Twitter and Reddit. Based on the quantitative analysis, the paper argues that both platform and climate change beliefs influence register in terms of epistemic stance. Overall, Reddit uses more epistemic stance markers than Twitter. Sceptics use less hedging of likelihood and more lexis evaluating the factuality and reliability of their opponents. The interpersonal functions of epistemic stance are shown to be associated with different platform uses and affordances and with the different goals, worldviews, and concerns of the factions. The study thus calls for further linguistic comparison of platforms and different factions within the platforms.
The influence of liquid conductivity on pulsed discharge generated by a vertical falling liquid electrode device
Authors: Qi Zhihua , Wang Xi , Xia Yang , Zhao Zhiguo , Liu Dongping , Shi Shuhui , Ji Xiaorui , Zhou Zhenyu 
Published: October 2022

Abstract
A novel atmospheric gas–liquid discharge device has been designed in this study to generate discharge directly around the vertical falling liquid column. The device is made up of a quartz tube, an H.V. electrode attached to the outer wall of the quartz tube, and a vertical falling liquid column acting as the liquid ground electrode in the quartz tube`s internal center. An ICCD camera and a 2D axisymmetric numerical modeling are used to analyze the temporal-spatial evolution of the pulsed discharge around the liquid electrode. The results of the experiment and simulation indicate that the propagation and sustaining time of the discharge are strongly dependent on applied voltage and liquid electrode conductivity. It is found that there is no discharge observed around the liquid electrode with a conductivity of 0.05 mS cm−1. As the conductivity of the liquid electrode increases, the electric field applied in the gas phase increases. When the conductivity is greater than 0.05 mS cm−1, the discharge is initiated around the intermediate region of the liquid electrode, then develops upwards and downwards along the liquid electrode. The discharge sustaining time increases with the increase of the conductivity and applied voltage. When the liquid electrode is replaced by the stainless-steel electrode, it is discovered that the discharge sustaining time of the stainless-steel electrode is lower than that of the liquid electrode at the same applied voltage. Analysis suggests that the prolonged discharge sustaining time is caused by the gas capacitance that is increased by water vapor released from the liquid electrode. The simulation results indicate that the discharge around the liquid electrode is constrained to the cone-shaped distribution by the non-uniform electric field around the liquid electrode when the conductivity increases to 200 mS cm−1 .
Quenching of bright and dark excitons via deep states in the presence of SRH recombination in 2D monolayer materials
Authors: Szmytkowski Jȩdrzej 
Published: October 2022

Abstract
Two-dimensional (2D) monolayer materials are interesting systems due to an existence of optically non-active dark excitonic states. In this work, we formulate a theoretical model of an excitonic Auger process which can occur together with the trap-assisted recombination in such 2D structures. The interactions of intravalley excitons (bright and spin-dark ones) and intervalley excitons (momentum-dark ones) with deep states located in the energy midgap have been taken into account. The explanation of this process is important for the understanding of excitonic and photoelectrical processes which can coexist in 2D materials, like transition metal dichalcogenides and perovskites.
Unified theory of spin and charge in a ferromagnet
Authors: Tchernyshyov Oleg 
Published: October 2022

Abstract
We derive a unified theory of spin and charge degrees of freedom in a ferromagnet. The spin-transfer torque and spin electromotive force are examined from the coarse-grained perspective of collective coordinates. The resulting equations of motion reflect a balance of conservative, gyroscopic (Berry-phase), and dissipative forces. We then expand the space of collective coordinates by adding the electric charge. The adiabatic spin-transfer torque and spin electromotive force (emf) turn out to be a gyroscopic force; their nonadiabatic counterparts are a dissipative force.
Lattice distortions and the metal–insulator transition in pure and Ti-substituted Ca3Ru2O7
Authors: Petkov V , Rao T Durga , Zafar A , Abeykoon A M Milinda , Fletcher E , Peng J , Mao Z Q , Ke X 
Published: October 2022

Abstract
We report pair distribution function studies on the relationship between the metal–insulator transition (MIT) and lattice distortions in pure and Ti-substituted bilayer Ca3Ru2O7. Structural refinements performed as a function of temperature, magnetic field and length scale reveal the presence of lattice distortions not only within but also orthogonal to the bilayers. Because of the distortions, the local and average crystal structure differ across a broad temperature region extending from room temperature to temperatures below the MIT. The coexistence of distinct lattice distortions is likely to be behind the marked structural flexibility of Ca3Ru2O7 under external stimuli. This observation highlights the ubiquity of lattice distortions in an archetypal Mott system and calls for similar studies on other families of strongly correlated materials.
Design and construction of a lab-made calorimetric system for specific loss power (SLP) measurements in suspensions of magnetic nanoparticles
Authors: Suárez Gómez S E , Velásquez A A , Velásquez Salazar A A , Ospina A M 
Published: October 2022

Abstract
The specific loss power (SLP) is a figure of merit in nanomagnetism, which allows to classify systems of magnetic nanoparticles (MNPs) according to their capability to dissipate heating power in response to the energy absorbed from an alternating magnetic field (AMF) at radiofrequencies. SLP magnitude is relevant in biological applications of MNPs, such as nanomedicine, where the thermal energy released by these nanostructures can be used to produce apoptosis in cancer cells, becoming a promising alternative for the treatment of malignant tumors. In this work we present details of the design and construction of a lab-made electromagnetic system to perform SLP measurements in systems of MNPs. The system is composed by an actuation stage, which generates the AMF to excite the sample, a thermal insulation stage between the sample and its surroundings, and two sensing stages: the first one for measuring the magnetic field applied to the sample and the second one for measuring the changes of temperature of the sample. The system developed allows to reach AMFs around 7.7 kA m−1 in the center of the actuation coil, operating at 260 kHz and with a power consumption less than 150 W. The architecture of the system allows the automatization and control of SLP measurements from remote places through the IEEE 488 bus available in the power source and a graphic interface developed in LabVIEW software, which allows to visualize temperature versus time measurements, control the magnetic field amplitude and store the data in a public folder available in the cloud. Some results are presented, where the system is employed to measure the SLP of a colloidal suspension of MNPs of maghemite (γ-Fe2O3) stabilized with sodium polyacrylate. The results obtained show a satisfactory performance of the device to measure the SLP of samples of MNPs for different purposes.
A 3D radius compensation method to reduce the influence of probe fluctuation error in blade space curve measurement
Authors: Wang Xingzhao , Zhang Xu , Jia Guangjie , Cao Jianbin 
Published: October 2022

Abstract
In the contact measurement of the coordinate measuring machine, the space curve cannot obtain the third-dimension information of its compensation vector by itself. Moreover, the fluctuation error of the probe will cause the unknown spatial offset of the contact point of the curve, making it more difficult to obtain the third-dimensional information of the compensation vector. A three-dimensional radius compensation method based on iterative third-dimensional information is proposed in this paper. The distance value between the intersection point and the compensation point is used as the convergence condition to approximate the offset contact point. The simulation test results show that the error accuracy of radial parameters is 0.1 μm and the error accuracy of Z-direction parameters is 1 μm when only Z-direction fluctuation error is considered. The real machine test results show that this method is closer to the actual situation than the two-dimensional radius compensation method.
Sparse representation and modified density peak clustering-based state identification for multimode processes
Authors: Wang Zhaojing , Chen Bin , Zheng Ying , Wang Yang , Yan Xiaoyun 
Published: October 2022

Abstract
Industrial processes with high-dimensional data are generally operated with mixed normal/faulty states in different modes, making it difficult to automatically and accurately identify the faults. In this paper, a state identification framework is proposed for multimode processes. First, a key variable selection approach is presented based on sparse representation to eliminate redundant variables. Then, modified density peak clustering is proposed to identify different states, in which a distance measurement with a time factor is constructed to select all the possible cluster centers. Then, the sum of squared errors-based approach is developed to determine the optimal cluster centers automatically. Further, considering that the mode attributes may be mixed with the fault attributes, a two-step ‘coarse-to-fine identification’ strategy is designed to precisely identify the modes and the faults in each mode. Finally, three cases including a numerical simulation, Tennessee Eastman benchmark process and an actual semiconductor manufacturing process are presented to show the feasibility of the proposed method.
Modification of the Johnson–Cook model for metal at a wide range of strain rates and application in the dynamic response of honeycomb panels
Authors: Li Shuangbei , Su Quanfu , Wang Xiangyu , Wu Yuan , Zhao Xuan , Chang Yanjun 
Published: October 2022

Abstract
In this paper, the H/V-Johnson Cook (JC)/Cowper Symonds (CS) dynamic constitutive relation suitable for a wide range of strain rates is proposed. Based on the experimental data in the existing literatures, the parameters of the H/V-JC/CS constitutive model for metal materials are calibrated by using the global optimization algorithm, which has high accuracy, convenient application, and is unlimited in number of parameters. The obtained parameters do not depend on the initial value and are the global optimal combination. The corresponding ABAQUS visual user material subroutine is compiled and imported into the finite element analysis for the dynamic response of the honeycomb panel structure. The influence of geometric parameters on the energy absorption effect of honeycomb panels under impact load is explored. The research shows that the proposed H/V-JC/CS constitutive model can well describe the mechanical behavior of various metals in a wide range of strain rates under impact load, and can be used in ABAQUS dynamic explicit environment. It provides a high-precision engineering application analysis model for metal structures under dynamic load.
Reaction mechanism of core–shell Al@SiO2 nanoparticles from molecular dynamics simulations
Authors: Zhang Jinping , Wang Erping , Yu Chunlai , Xie Jingpei , Tang Cuiming , Jia Yu 
Published: October 2022

Abstract
Nanothermites play an important roles in both civil and military fields. In this paper, using molecular dynamics simulations with reactive force field (ReaxFF), we study the thermally induced reactions of core–shell Al@SiO2 nanoparticles to elucidate the underlying reaction mechanism between Al and a metallic oxide. Core–shell Al@SiO2 nanoparticles undergo a four-stage explosive reaction after being heated to the ignition temperature. They are, in sequence: (i) Heat is released from the core–shell interface to Al core, and Al core begins to melt. (ii) The melted Al core accelerates the redox exothermic reaction, producing a pure Si shell. (iii) The Si shell moves towards the center of the system under electric field induction, and the distorted AlnO (n = 4, 5) clusters are ejected from the system’s surface. (iv) The detonation of the nanoparticles, and the formation of final products. Notably, the electric-field-induced Al atoms diffuse faster than the O atoms throughout the reaction. Our findings provide a reference guide for the reactions of nanothermites.
Enhanced piezoelectric response in BTO NWs-PVDF composite through tuning of polar phase content
Authors: Hazra Snehamoyee , Ghatak Ankita , Ghosh Arnab , Sengupta Subhamita , Raychaudhuri A K , Ghosh Barnali 
Published: October 2022

Abstract
We have fabricated a flexible, environment friendly piezoelectric nanogenerator (PENG) based on the ferroelectric Polyvinylidene fluoride (PVDF) composite incorporated with Barium titanate (BaTiO3) nanowires (NWs) of piezoelectric coefficient d
33 = 308 pm V−1. The single-layered PENG can deliver output power density of 10 μW cm−2 and an output voltage of 2 V with a nominal mechanical load of 1 kPa. BaTiO3 (BTO) NWs of different concentrations were incorporated into PVDF to tune the polar phase content, internal resistance, and optimize the output power. We show that there exists a critical value of BTO NWs loading of 15 wt%, beyond which the piezoelectric energy harvesting characteristics of the PVDF nanocomposites decrease. The oxygen vacancies present in the BTO NWs surface attract the fluorine ions of PVDF chain and favour the formation of β phase. The enhanced value of dielectric constant and dielectric loss of BTO-PVDF samples in the low frequency region suggest strong interfacial polarization in the composite system. The fabricated PENG can charge a super-capacitor up to 4 V within 35 s. The origin of the high power output from the BTO (15 wt%)-PVDF composite is attributed to the combined effect of enhanced polar phase content, strong interfacial polarization, and reduced internal resistance. This study provides an effective pathway in enhancing the performance of BTO-PVDF based piezoelectric energy harvesters.