bluuebunny/crossref_metadata_2025_split huggingface dataset:
Optimalisasi Media Pembelajaran Puzzle Maker Untuk Meningkatkan Pemahaman Kosa Kata Bahasa Arab: Studi Inovasi dalam Pembelajaran
Authors: Alaifi Aulia Ashrafah , Putri Bella Tiara , Hayati Devi Khumairah , Basri Btr Mhd Hasan , Nasution Sahkholid 
Published: January 2025

Dalam dunia pendidikan, guru sering melakukan berbagai cara untuk meningkatkan pemahaman siswa terhadap materi pelajaran. Salah satunya adalah dengan menciptakan media pembelajaran yang inovatif dan menarik, agar siswa tidak merasa bosan selama proses belajar dan dapat merasakan suasana yang berbeda di setiap pertemuan. Kurangnya pemahaman kosa kata Bahasa arab siswa menjadi masalah dalam pembelajaran karena metode yang di gunakan kurang tepat atau tidak menarik, hal tersebut yang kemudian menjadi tantangan dan kendala bagi para pengajar. Pada penelitian kali ini memiliki tujuan untuk meningkatkan motivasi belajar siswa,memberikan kontribusi untuk meningkatkan pemahaman kosa kata Bahasa arab siswa dan Untuk menyajikan puzzle maker sebagai alternatif media pembelajaran yang inovatif dan aplikatif bagi pengajar bahasa Arab. Penelitian ini menggunakan metode penelitian kualitatif dengan model studi Pustaka yaitu dengan cara mengumpulkan data dari berbagai sumber akademik sebagai sumber datanya. Hasil penelitian ini mengungkapkan bahwa pembelajaran berbasis puzzle maker merupakan salah satu inovasi dalam dunia pendidikan. Selain itu, penerapan metode ini juga memberikan dampak positif pada perkembangan kognitif siswa, seperti meningkatkan antusiasme mereka dalam mengikuti pembelajaran dan mempermudah pemahaman terhadap materi yang disampaikan oleh guru.
In the world of education, teachers often use various methods to improve students' understanding of subject matter. One of them is by creating innovative and interesting learning media, so that students do not feel bored during the learning process and can experience a different atmosphere at each meeting. Students' lack of understanding of Arabic vocabulary becomes a problem in learning because the methods used are inappropriate or uninteresting, this then becomes a challenge and obstacle for teachers. This research aims to increase students' learning motivation, contribute to improving students' understanding of Arabic vocabulary and to present puzzle makers as an innovative and applicable alternative learning media for Arabic teachers. This research uses a qualitative research method with a library study model, namely by collecting data from various academic sources as the data source. The results of this research reveal that puzzle maker-based learning is one of the innovations in the world of education. Apart from that, the application of this method also has a positive impact on students' cognitive development, such as increasing their enthusiasm for learning and making it easier to understand the material presented by the teacher
SDSS J100711.74+193056.2: A Candidate Common Motion Substellar Companion to the Nearest B-type Star Regulus
Authors: Mamajek Eric E. , Burgasser Adam J. 
Published: January 2025

Abstract
The L9 dwarf SDSS J100711.74+193056.2 is situated 7

.

°

5 north of the nearest B-type star Regulus (d = 24.3 ± 0.2 pc), part of a stellar quadruplet. The object is at similar distance (d = 21.9 ± 1.0 pc) as Regulus, with a 3D separation of

3
.

9

−
0.5

+
0.6

pc (~1.6 tidal radii from Regulus), and shares tangential motion within 2 km s−1, hinting at a physical connection. Near-infrared spectroscopy with Keck/NIRES finds that SDSS J100711.74+193056.2 also has a comparable radial velocity as Regulus A and B, a metallicity similar to Regulus B, and a spectral morphology consistent with the estimated 1–2 Gyr total age of Regulus's close pre-white-dwarf companion. Taken together, these observations indicate that SDSS J100711.74+193056.2 is a very widely separated and potentially physically bound companion to Regulus, with a binding energy and mass ratio comparable to other wide star-brown dwarf systems. It joins a growing list of brown dwarfs at the L-dwarf/T-dwarf transition with independent constraints on physical properties such as age and metallicity.
Discovery and Characterization of an Eccentric, Warm Saturn Transiting the Solar Analog TOI-4994*
Authors: Rodríguez Martínez Romy , Eastman Jason D. , Collins Karen A. , Rodriguez Joseph E. , Charbonneau David , Quinn Samuel N. , Latham David W. , Ziegler Carl , Brahm Rafael , Fairnington Tyler R. , Ulmer-Moll SolÉne , Stassun Keivan G. , Suarez Olga , Guillot Tristan , Hobson Melissa J. , Winn Joshua N. , Kanodia Shubham , Schlecker Martin , Butler R. P. , Crane Jeffrey D. , Shectman Steve , Teske Johanna K. , Osip David , Beletsky Yuri , Battley Matthew P. , Psaridi Angelica , Figueira Pedro , Lendl Monika , Bouchy François , Udry Stéphane , Kunimoto Michelle , Mékarnia Djamel , Abe Lyu , Trifonov Trifon , Tala Pinto Marcelo , Eberhardt Jan , Espinoza Nestor , Henning Thomas , Jordán Andrés , Rojas Felipe I. , Barkaoui Khalid , Relles Howard M. , Srdoc Gregor , Collins Kevin I. , Seager Sara , Shporer Avi , Vezie Michael , Hedges Christina , Mireles Ismael 
Published: January 2025

Abstract
We present the detection and characterization of TOI-4994b (TIC 277128619b), a warm Saturn-sized planet discovered by the NASA Transiting Exoplanet Survey Satellite. TOI-4994b transits a G-type star (V = 12.6 mag) with a mass, radius, and effective temperature of

M

⋆

=
1.00

5

−
0.061

+
0.064

M

⊙

,

R

⋆

=
1.05

5

−
0.037

+
0.040

R

⊙

, and T
eff = 5640 ± 110 K. We obtained follow-up ground-based photometry from the Las Cumbres Observatory and the Antarctic Search for Transiting ExoPlanets telescopes, and we confirmed the planetary nature of TOI-4994b with multiple radial velocity observations from the Planet Finder Spectrograph, CHIRON, High Accuracy Radial velocity Planet Searcher, Fiber-fed Extended Range Optical Spectrograph, and CORALIE instruments. From a global fit to the photometry and radial velocities, we determine that TOI-4994b is in a 21.5 day eccentric orbit (e = 0.32 ± 0.04) and has a mass of

M

P

=
0.28

0

−
0.034

+
0.037

M

J

, a radius of

R

P

=
0.76

2

−
0.027

+
0.030

R

J

, and a Saturn-like bulk density of

ρ
p

=
0.7

8

−
0.14

+
0.16

g

cm

-
3

. We find that TOI-4994 is a potentially viable candidate for follow-up stellar obliquity measurements. TOI-4994b joins the small sample of warm Saturn analogs and thus sheds light on our understanding of these rare and unique worlds.
Atmospheric Distribution and Escape of Odd Nitrogen on Mars
Authors: Gu 顾 Hao 浩 , Wu 吴 Xiaoshu 晓姝 , Cui 崔 Jun 峻 , Huang 黄 Xu 旭 , Li 李 Wenlong 文龙 , Zhao 赵 Jinjin 金锦 , Li 李 Lei 磊 
Published: January 2025

Abstract
The total nitrogen budget in the Martian upper atmosphere is significantly contributed by the presence of odd nitrogen, mainly in the form of NO and ground-state or excited-state N. The distribution of these species can be effectively probed by airglow emission on Mars, and understanding such a distribution is crucial for unveiling the thermal balance in the Martian upper atmosphere. In this study, we construct a sophisticated 1D photochemical model that also incorporates vertical diffusion and photoelectron production and transport. Such a model is used for obtaining the atmospheric distribution of both NO and different electronic states of atomic N on the dayside of Mars. Our study reproduces well the available measurements of relevant species in the combined Martian upper atmosphere and ionosphere, disentangling various chemical pathways in their contributions to odd nitrogen production and destruction. In addition, the photochemical model is combined with a Monte Carlo kinetic model to derive the dayside total N escape rate to be 3.3 × 1023 s−1 driven by photochemistry. This study corroborates previous findings that N2 photolysis and N

2

+

dissociative recombination are the main contributors to the photochemical escape of N on Mars. Moreover, it underscores the significant role of photochemistry in shaping the long-term evolution of the Martian atmosphere.
From Halos to Galaxies. VI. Improved Halo Mass Estimation for SDSS Groups and Measurement of the Halo Mass Function
Authors: Zhao Dingyi , Peng Yingjie , Jing Yipeng , Yang Xiaohu , Ho Luis C. , Renzini Alvio , Gallazzi Anna R. , Lyu Cheqiu , Maiolino Roberto , Dou Jing , Gao Zeyu , Gu Qiusheng , Mannucci Filippo , Mo Houjun , Wang Bitao , Wang Enci , Wang Kai , Wang Yu-Chen , Xu Bingxiao , Yuan Feng , Zhu Xingye 
Published: January 2025

Abstract
In ΛCDM cosmology, galaxies form and evolve in their host dark matter (DM) halos. Halo mass is crucial for understanding the halo–galaxy connection. The abundance-matching (AM) technique has been widely used to derive the halo masses of galaxy groups. However, the quenching of the central galaxy can decouple the coevolution of its stellar mass and DM halo mass. Different halo assembly histories can also result in significantly different final stellar masses of the central galaxies. These processes can introduce substantial uncertainties into the halo masses derived from the AM method, particularly leading to a systematic bias between groups with star-forming centrals (blue groups) and passive centrals (red groups). To improve this, we have developed a new machine learning (ML) algorithm that accounts for these effects and is trained on simulations. Our results show that the ML method eliminates the systematic bias in the derived halo masses for blue and red groups and is, on average, ~one-third more accurate than the AM method. With careful calibrations of observable quantities from simulations and observations from the Sloan Digital Sky Survey (SDSS), we apply our ML model to the SDSS groups to derive their halo masses down to 1011.5
M
⊙ or even lower. The derived SDSS group halo mass function agrees well with the theoretical predictions, and the derived stellar-to-halo mass relations for both the red and blue groups match well with those obtained from direct weak-lensing measurements. These new halo mass estimates enable more accurate investigation of the galaxy–halo connection and the role of halos in galaxy evolution.
Repeating Partial Tidal Encounters of Sun-like Stars Leading to Their Complete Disruption
Authors: Liu 刘 Chang 畅 , Yarza Ricardo , Ramirez-Ruiz Enrico 
Published: January 2025

Abstract
Stars grazing supermassive black holes on bound orbits may produce periodic flares over many passages, known as repeating partial tidal disruption events (TDEs). Here, we present 3D hydrodynamic simulations of Sun-like stars over multiple tidal encounters. The star is significantly restructured and becomes less concentrated as a result of mass loss and tidal heating. The vulnerability to mass loss depends sensitively on the stellar density structure, and the strong correlation between the fractional mass loss ΔM/M
* and the ratio of the central and average density

ρ

c

/

ρ

¯

, which was initially derived in disruption simulations of main-sequence stars, also applies for stars strongly reshaped by tides. Over multiple orbits, the star loses progressively more mass in each encounter and is doomed to a complete disruption. Throughout its lifetime, the star may produce numerous weak flares (depending on the initial impact parameter), followed by a couple of luminous flares whose brightness increases exponentially. Flux-limited surveys are heavily biased toward the brightest flares, which may appear similar to the flare produced by the same star undergoing a full disruption on its first tidal encounter. This places new challenges on constraining the intrinsic TDE rates, which need to take repeating TDEs into account. Other types of stars with different initial density structures (e.g., evolved stars with massive cores) follow distinct evolution tracks, which might explain the diversity of the long-term luminosity evolution seen in recently uncovered repeaters.
Star-forming Nuclear Clusters in Dwarf Galaxies Mimicking Active Galactic Nucleus Signatures in the Mid-infrared
Authors: Sturm Megan R. , Hayes Bayli , Reines Amy E. 
Published: January 2025

Abstract
Effectively finding and identifying active galactic nuclei (AGNs) in dwarf galaxies is an important step in studying black hole formation and evolution. In this work, we examine four mid-infrared (IR)-selected AGN candidates in dwarf galaxies with stellar masses between M
⋆ ~ 108 and 109
M
⊙ and find that the galaxies are host to nuclear star clusters (NSCs) that are notably rare in how young and massive they are. We perform photometric measurements on the central star clusters in our target galaxies using Hubble Space Telescope optical and near-IR imaging and compare their observed properties to models of stellar population evolution. We find that these galaxies are host to very massive (~107
M
⊙), extremely young (≲8 Myr), and dusty (0.6 ≲ A
v ≲ 1.8) NSCs. Our results indicate that these galactic nuclei have ongoing star formation, are still at least partially obscured by clouds of gas and dust, and are most likely producing the extremely red AGN-like mid-IR colors. Moreover, prior work has shown that these galaxies do not exhibit X-ray or optical AGN signatures. Therefore, we recommend caution when using mid-IR color–color diagnostics for AGN selection in dwarf galaxies, since, as directly exemplified in this sample, they can be contaminated by massive star clusters with ongoing star formation.
ALMA Spectral Survey of an Eruptive Young Star, V883 Ori (ASSAY). II. Freshly Sublimated Complex Organic Molecules in the Keplerian Disk
Authors: Jeong Jae-Hong , Lee Jeong-Eun , Lee Seonjae , Baek Giseon , Kang Ji-Hyun , Lee Seokho , Kim Chul-Hwan , Yun Hyeong-Sik , Aikawa Yuri , Herczeg Gregory J. , Johnstone Doug , Cieza Lucas 
Published: January 2025

Abstract
We present an investigation of complex organic molecules (COMs) in the spatially resolved Keplerian disk around V883 Ori, an eruptive young star, based on a spectral survey carried out with the Atacama Large Millimeter/submillimeter Array in Band 6 (220.7−274.9 GHz). We identified about 3700 molecular emission lines and discovered 23 COMs in the disk. We estimated the column densities of the COMs detected, using the iterative LTE line-fitting method. According to our analyses, using only optically thin lines is critical to deriving the reliable column densities of COMs. Therefore, covering a large frequency range is important for the studies of COMs. The most distinct phenomenon found from the spectra of the V883 Ori disk is that nitrogen-bearing COMs other than CH3CN are missing, whereas various oxygen-bearing COMs, except for the CH2OH-bearing molecules, are detected. The missing CH2OH-bearing COMs may indicate the warm water-ice dominant environment for forming COMs. We compared our results with various objects in different evolutionary stages, from Class 0 hot corinos to a solar system comet 67P/Churyumov-Gerasimenko, to examine the effect of evolution on the COM compositions. In general, the COM abundances relative to methanol in V883 Ori are higher than in the hot corinos and hot cores, while they are comparable to the cometary values. This may indicate the planet-forming material chemically evolves in the disk midplane after being accreted from the envelope. In addition, as found in the comet 67P/Churyumov-Gerasimenko, nitrogen might also be trapped as ammonium salt within the dust grains in the V883 Ori disk.
Magnetic Activity of TESS Objects Observed in the LAMOST Medium-resolution Spectral Survey
Authors: Su Tianhao , Zhang Li-yun , Misra Prabhakar , Han Xianming L. , Wang Yinpeng , Li Wenjie , Zhu Zhongzhong , Pi Qingfeng , Lu Hongpeng 
Published: January 2025

Abstract
A combination of spectroscopic and photometric observations provides an excellent data sample for studying stellar chromospheric activity. We have combined LAMOST medium-resolution spectra with TESS 2 minute light curves and extracted over 530,000 spectra and 110,000 light curves from more than 40,000 stars. We have quantified the Hα line intensity in each spectrum and found that 38,659 spectra from 7002 stars exhibited excess Hα emission and that the intensity of stellar chromospheric activity increases with later spectral types. We also discovered that the boundary value between the saturated and unsaturated regions of chromospheric activity for different spectral type stars is around Ro = 0.1. By analyzing the TESS light curves, we identified 31,539 flare events from 4120 stars. Through these flare events, we determined that the flare-frequency proportion of stars increases with later spectral types. We have found that the power-law index of the flare-frequency distribution for F-, G-, K-, and M-type stars is around 2.0, while that for A-type stars is 1.3. Additionally, we observed that the amplitude of brightness variations caused by modulation due to starspot coverage (R
eff) is positively correlated with both the flare intensity and intensity of chromospheric activity and that the chromospheric activity was generally stronger in flare stars as compared to nonflare stars. We also found that within 300 pc, the proportion of chromospherically active stars and flare stars decreases with increasing distance from the Galactic disk. Finally, we discovered six flare events from the Hα variation and estimated their energies.
Metallicity Dependence of Giant Planets around M Dwarfs
Authors: Gan Tianjun , Theissen Christopher A. , Wang Sharon X. , Burgasser Adam J. , Mao Shude 
Published: January 2025

Abstract
We investigate the stellar metallicity ([Fe/H] and [M/H]) dependence of giant planets around M dwarfs by comparing the metallicity distribution of 746 field M dwarfs without known giant planets with a sample of 22 M dwarfs hosting confirmed giant planets. All metallicity measurements are homogeneously obtained through the same methodology based on the near-infrared spectra collected with a single instrument SpeX mounted on the NASA Infrared Telescope Facility. We find that (1) giant planets favor metal-rich M dwarfs at a 4σ–5σ confidence level, depending on the band of spectra used to derive metallicity; (2) hot (a/R
*≤20) and warm (a/R
* > 20) Jupiters do not show a significant difference in the metallicity distribution. Our results suggest that giant planets around M and FGK stars, which are already known to prefer metal-rich hosts, probably have a similar formation channel. In particular, hot and warm Jupiters around M dwarfs may have the same origin as they have indistinguishable metallicity distributions. With the refined stellar and planetary parameters, we examine the stellar metallicities and the masses of giant planets where we find no significant correlation. M dwarfs with multiple giant planets or with a single giant planet have similar stellar metallicities. Mid-to-late type M stars hosting gas giants do not show an apparent preference to higher metallicities compared with those early M dwarfs with gas giants and field M dwarfs.
Magnetic Reconnection: An Alternative Explanation of Radio Emission in Galaxy Clusters
Authors: Ghosh Subham , Bhat Pallavi 
Published: January 2025

Abstract
Observations of galaxy clusters show radio emission extended over almost the system scale, necessitating mechanisms for particle acceleration. Previous models for acceleration, such as diffusive shock acceleration and that due to turbulence, can fall short in terms of efficiency. In this Letter, we propose the possibility of acceleration via magnetic reconnection. In particular, we invoke the plasmoid instability, which has been previously applied to understand particle energization in high-energy systems. Turbulence in galaxy clusters leads to fluctuation dynamos that are known to generate magnetic field structures consisting of sharp reversals. These form natural sites of reconnection. We perform particle-in-cell simulations of the plasmoid instability in collisionless and nonrelativistic plasmas. We show that the resulting electron energy spectra have power-law indices that are consistent with those inferred from observations. Our estimates show that the acceleration timescales are much smaller than the lifetime of the reconnecting magnetic structures indicating the feasibility of our model. The synchrotron radio luminosity estimate is about 1041 erg s−1, agreeing with observations. Finally, we find that the maximum achievable Lorentz factor can go up to 105 indicating that acceleration due to magnetic reconnection is a promising avenue for understanding the origin of nonthermal emission in galaxy clusters.
Implications of Differentiated Late Accretion for the Volatile Inventory of the Bulk Silicate Earth
Authors: Grewal Damanveer S. , Manilal Varun 
Published: January 2025

Abstract
Earth is believed to have acquired its highly siderophile element (HSE) inventory through the late accretion of ∼0.3%–0.5% of its mass in chondrite-like materials, following the main stage of its growth. Late accretion, particularly if it originated from the outer solar system, could have significantly contributed to the bulk silicate Earth’s (BSE = mantle + crust + hydrosphere + atmosphere) carbon–nitrogen–hydrogen (C–N–H) inventory. However, recent studies, noting differences between the HSE inventory of the Earth and Moon’s mantle, suggest that relatively large lunar-sized differentiated impactors, rather than small chondritic projectiles, delivered HSEs to Earth’s mantle during late accretion. The implications of a differentiated late accretion event for the BSE’s C–N–H inventory remain unclear. In this study, we modeled the equilibrium partitioning of highly volatile C–N–H and moderately volatile sulfur–selenium–tellurium (S–Se–Te) between the atmosphere, magma ocean (MO), and core of lunar-sized or slightly larger impactors. The impactor’s MO-degassed atmosphere contained most of its C–N–H inventory, whereas almost all of the S–Se–Te was present in its core or mantle. Given the low escape velocity of lunar-sized impactors, the MO-degassed atmosphere was likely dissipated quickly after core formation. As a result, in contrast to S–Se–Te, the contribution of differentiated late accretion to BSE’s C–N–H inventory was limited, irrespective of its inner or outer solar system origin. The C–N–H-depleted nature of differentiated objects suggests that most of BSE’s highly volatile inventory was delivered by primitive chondritic materials toward the final stages of Earth’s accretion, before the Moon-forming event.
Assessing Marketplaces’ Role in Economic Sustainability of South African SMMEs
Authors: Moagi Thato J. , Thomas Peta , Mara Cashandra C. 
Published: January 2025

Orientation: Research on marketplaces and their role in the economic sustainability of small, medium and micro enterprises (SMMEs) remains sparse and the researchers need to establish the qualities necessary to support SMME viability.Research purpose: This empirical study proposed, designed and employed a cataloguing field methodology instrument to effectively assess the physical qualities and attributes of informal and formal marketplaces in South Africa.Motivation for the study: Marketplaces are vital drivers of poverty alleviation and job creation, which inspired this study.Research design, approach and method: A total of 34 marketplaces in Gauteng, South Africa, were randomly selected and catalogued, based on availability, using the same field-ranking form for both formal and informal marketplaces for comparison purposes.This study could inform what is needed to make marketplaces more economically sustainable for their SMMEs and achieve a comprehensive national directory of marketplaces in South Africa to ensure the economic sustainability of SMMEs in the country.Main findings: A new methodology was developed to catalogue marketplaces and SMMEs in Gauteng.Practical/managerial implications: The functional characteristics of marketplaces are important to owners and operators, and knowledge of these preferences is vital to policy makers and managers.Contribution/value add: This novel method will effectively assist relevant bodies such as municipal, provincial and national government to effectively capture and catalogue physical marketplaces by their valuable qualities and characteristics.