bluuebunny/crossref_metadata_2025_split huggingface dataset:
Water emission tracing active star formation from the Milky Way to high-z galaxies
Authors: Dutkowska K. M. , Kristensen L. E. 
Published: August 2022

Context. The question of how most stars in the Universe form remains open. While star formation predominantly takes place in young massive clusters, the current framework focuses on isolated star formation. This poses a problem when trying to constrain the initial stellar mass and the core mass functions, both in the local and distant Universe.
Aims. One way to access the bulk of protostellar activity within star-forming clusters is to trace signposts of active star formation with emission from molecular outflows. These outflows are bright (e.g., in water emission), which is observable throughout cosmological times, providing a direct observational link between nearby and distant galaxies. We propose to utilize the in-depth knowledge of local star formation as seen with molecular tracers, such as water, to explore the nature of star formation in the Universe.
Methods. We present a large-scale statistical galactic model of emission from galactic active star-forming regions. Our model is built on observations of well-resolved nearby clusters. By simulating emission from molecular outflows, which is known to scale with mass, we create a proxy that can be used to predict the emission from clustered star formation on galactic scales. In particular, the para-H2O 202 − 111 line is well suited for this purpose as it is one of the brightest transitions observed toward Galactic star-forming regions and is now routinely observed toward distant galaxies.
Results. We evaluated the impact of the most important global star formation parameters (i.e., initial stellar mass function, molecular cloud mass distribution, star formation efficiency, and free-fall time efficiency) on simulation results. We observe that for emission from the para-H2O 202 − 111 line, the initial mass function and molecular cloud mass distribution have a negligible impact on the emission, both locally and globally, whereas the opposite holds for star formation efficiency and free-fall time efficiency. Moreover, this water transition proves to be a low-contrast tracer of star formation, with ∫Iν ∝ Menv.
Conclusions. The fine-tuning of the model and adaptation to morphologies of distant galaxies should result in realistic predictions of observed molecular emission and make the galaxy-in-a-box model a tool for analyzing and better understanding star formation throughout cosmological times.
The miniJPAS survey: White dwarf science with 56 optical filters
Authors: López-Sanjuan C. , Tremblay P.-E. , Ederoclite A. , Vázquez Ramió H. , Cenarro A. J. , Marín-Franch A. , Varela J. , Akras S. , Guerrero M. A. , Jiménez-Esteban F. M. , Lopes de Oliveira R. , Chies-Santos A. L. , Fernández-Ontiveros J. A. , Abramo R. , Alcaniz J. , Benítez N. , Bonoli S. , Carneiro S. , Cristóbal-Hornillos D. , Dupke R. A. , Mendes de Oliveira C. , Moles M. , Sodré L. , Taylor K. 
Published: August 2022

Aims. We analyze the white dwarf population in miniJPAS, the first square degree observed with 56 medium-band, 145 Å in width optical filters by the Javalambre Physics of the accelerating Universe Astrophysical Survey (J-PAS), to provide a data-based forecast for the white dwarf science with low-resolution (R ∼ 50) photo-spectra.
Methods. We define the sample of the bluest point-like sources in miniJPAS with r <  21.5 mag, a point-like probability larger than 0.5, (u − r)< 0.80 mag, and (g − i)< 0.25 mag. This sample comprises 33 sources with spectroscopic information: 11 white dwarfs and 22 quasi-stellar objects (QSOs). We estimate the effective temperature (Teff), the surface gravity, and the composition of the white dwarf population by a Bayesian fitting to the observed photo-spectra.
Results. The miniJPAS data are sensitive to the Balmer series and the presence of polluting metals. Our results, combined with those from the Javalambre Photometric Local Universe Survey (J-PLUS) which has a lower spectral resolution but has already observed thousands of white dwarfs, suggest that J-PAS photometry would permit – down to r ∼ 21.5 mag and at least for sources with 7000 <  Teff <  22 000 K – both the classification of the observed white dwarfs into H-dominated and He-dominated with 99% confidence and the detection of calcium absorption for equivalent widths larger than 15 Å. The effective temperature is estimated with a 2% uncertainty, which is close to the 1% from spectroscopy. A precise estimation of the surface gravity depends on the available parallax information. In addition, the white dwarf population at Teff >  7000 K can be segregated from the bluest extragalactic QSOs, providing a clean sample based on optical photometry alone.
Conclusions. The J-PAS low-resolution photo-spectra would produce precise effective temperatures and atmospheric compositions for white dwarfs, complementing the data from Gaia. J-PAS will also detect and characterize new white dwarfs beyond the Gaia magnitude limit, providing faint candidates for spectroscopic follow-up.
Magnetic thread twisting in a simulated solar atmosphere
Authors: Sumner C. , Taroyan Y. 
Published: August 2022

Context. Plasma inflows accompany a variety of processes in the solar atmosphere such as heating of coronal loops and formation of prominences.
Aims. We model a stratified solar atmosphere, within which a simulated prominence thread experiences density accumulation via a plasma inflow designed to mimic the formation process. We aim to investigate the interaction of such a system with torsional perturbations, and the possible consequences.
Methods. The linearised equations of motion and induction are integrated to analyse the spatial and temporal evolution of torsional perturbations that are randomly driven at the photospheric footpoints.
Results. Our results demonstrate that magnetic threads will experience twist amplification. Different sources and sinks of energy and the corresponding amplification mechanisms are identified. Threads reaching chromospheric heights are most susceptible to magnetic twisting with the maximum twist occurring near their footpoints. The amplifying twists are associated with a standing wave behaviour along the simulated threads.
Conclusions. Our work suggests that torsional perturbations may be amplified within prominence threads, with strong magnetic twists forming at the footpoints. The amplification process is facilitated by small length scales in the background magnetic field. On the other hand, a small length scale in the background density inhibits growth. Possible consequences of the amplified twists, including their role in supporting the dense plasma within a prominence structure are discussed.
Quantitative spectroscopy of B-type supergiants
Authors: Weßmayer D. , Przybilla N. , Butler K. 
Published: August 2022

Context. B-type supergiants are versatile tools to address a number of highly-relevant astrophysical topics, ranging from stellar atmospheres over stellar and galactic evolution to the characterisation of interstellar sightlines and to the cosmic distance scale.
Aims. A hybrid non-local thermodynamic equilibrium (LTE) approach, involving line-blanketed model atmospheres computed under the assumption of LTE in combination with line formation calculations that account for deviations from LTE, is tested for quantitative analyses of B-type supergiants of mass up to about 30 M⊙, characterising a sample of 14 Galactic objects in a comprehensive way.
Methods. Hydrostatic plane-parallel atmospheric structures and synthetic spectra computed with Kurucz’s ATLAS 12 code together with the non-LTE line-formation codes DETAIL/SURFACE are compared to results from full non-LTE calculations with TLUSTY, and the effects of turbulent pressure on the models are investigated. High-resolution spectra at signal-to-noise ratio >130 are analysed for atmospheric parameters, using Stark-broadened hydrogen lines and multiple metal ionisation equilibria, and for elemental abundances. Fundamental stellar parameters are derived by considering stellar evolution tracks and Gaia early data release 3 (EDR3) parallaxes. Interstellar reddening and the reddening law along the sight lines towards the target stars are determined by matching model spectral energy distributions to observed ones.
Results. Our hybrid non-LTE approach turns out to be equivalent to hydrostatic full non-LTE modelling for the deeper photospheric layers of the B-type supergiants under consideration, where most lines of the optical spectrum are formed. Turbulent pressure can become relevant for microturbulent velocities larger than 10 km s−1. The changes in the atmospheric density structure affect many diagnostic lines, implying systematic changes in atmospheric parameters, for instance an increase in surface gravities by up to 0.05 dex. A high precision and accuracy is achieved for all derived parameters by bringing multiple indicators to agreement simultaneously. Effective temperatures are determined to 2–3% uncertainty, surface gravities to better than 0.07 dex, masses to about 5%, radii to about 10%, luminosities to better than 25%, and spectroscopic distances to 10% uncertainty typically. Abundances for chemical species that are accessible from the optical spectra (He, C, N, O, Ne, Mg, Al, Si, S, Ar, and Fe) are derived with uncertainties of 0.05–0.10 dex (1σ standard deviations). The observed spectra are reproduced well by the model spectra. The derived N/C versus N/O ratios tightly follow the predictions from Geneva stellar evolution models that account for rotation, and spectroscopic and Gaia EDR3 distances are closely matched. Finally, the methodology is tested for analyses of intermediate-resolution spectra of extragalactic B-type supergiants.
Les expériences du « local ». Variations et tensions autour de l’alimentation locale dans la région marseillaise
Authors: Consalès Jean-Noël , Guiraud Noé , Siniscalchi Valeria 
Published: August 2022

Cet article explore les variations de la notion de « local » à partir des pratiques et des discours d’acteurs divers impliqués dans des projets portant sur l’agriculture et l’alimentation. En suivant les divers modes de représentation du local – des discours des acteurs aux textes d’urbanisme – et les pratiques qui les mettent en œuvre, les auteurs (une anthropologue, un géographe et un urbaniste) interrogent la variabilité de cette notion afin d’analyser la manière dont elle est appropriée et reconfigurée en fonction des arènes dans lesquelles elle est mobilisée. Ce texte vise également à réfléchir aux limites et aux apports d’une approche pluridisciplinaire de ces questions : le pari est de montrer que la somme de ces trois approches permet de voir des éléments nouveaux qui n’émergeraient pas de chaque analyse individuelle.
Science facilitation: navigating the intersection of intellectual and interpersonal expertise in scientific collaboration
Authors: Cravens Amanda E. , Jones Megan S. , Ngai Courtney , Zarestky Jill , Love Hannah B. 
Published: August 2022

AbstractToday’s societal challenges, such as climate change and global pandemics, are increasingly complex and require collaboration across scientific disciplines to address. Scientific teams bring together individuals of varying backgrounds and expertise to work collaboratively on creating new knowledge to address these challenges. Within a scientific team, there is inherent diversity in disciplinary cultures and preferences for interpersonal collaboration. Such diversity contributes to the potential strength of the created knowledge but can also impede progress when teams struggle to collaborate productively. Facilitation is a professional practice-based form of interpersonal expertise that supports group members to do their best thinking. Although facilitation has been demonstrated to support group functioning in a wide range of contexts, its role in supporting scientific teams has been largely overlooked. This essay defines scientific facilitation as a form of interactional expertise and explains how facilitating scientific teams requires skills in managing interpersonal interactions as well as understanding how different types of disciplinary knowledge integrate in the creation of new knowledge. Next, it explains how this science facilitation expertise may be developed through metacognition. Finally, it provides examples of how scientific facilitation could be more widely incorporated into research by describing three pathways to expand the use of facilitation theory and techniques in collaborative scientific research: developing facilitation skills among scientists leading teams, using broadly trained facilitators, and using specialised science facilitators. The strengths and risks of each path are discussed, and criteria are suggested for selecting the right approach for a given team science project.
The current–voltage measurements under flat-top pulsed magnetic fields for non-ohmic transport study
Authors: Wei Wenqi , Yang Ming , Jin Shimin , Zhu Haipeng , Wang Junfeng , Han Xiaotao 
Published: August 2022

Investigation of the non-ohmic transport behaviors under high magnetic fields can provide a new way to explore novel field-induced phenomena. We present the current–voltage measurements under high magnetic fields based on the flat-top pulsed magnetic field system. Two different measurement strategies were compared, given that the excitation current swept continuously or increased by a series of pulses. For the short duration of the flat-top pulsed field, the continuous current method was adopted and well optimized to reduce the Joule heating and achieve the quasi-static measurements. Finally, the non-ohmic behaviors of a quasi-one-dimensional charge density wave Li0.9Mo6O17 were successfully studied under the magnetic field up to 30 T at 4.2 K, which was the first current–voltage measurements carried out in pulsed magnetic fields.
Influences of drought on the stability of an alpine meadow ecosystem
Authors: Zhang Tao , Ji Ximeng , Xu Mingjie , Zhao Guang , Zheng Zhoutao , Tang Yuanyuan , Chen Ning , Zhu Juntao , He Yongtao , Zhang Yangjian 
Published: August 2022

ABSTRACT

Drought plays a prominent role in affecting ecosystem stability and ecosystem productivity. Based on eddy covariance and climatic observations during 2012–2020, the Fisher discriminant analysis method was employed to accurately detect drought occurrences. Furthermore, the ecosystem water sensitivity and its resistance to drought were quantified to evaluate the ecosystem stability. The results showed that the alpine meadow suffered drought most frequently at the beginning of the growing seasons. However, drought during the peak growing seasons reduced the gross primary productivity (GPP) the most, by 30.5 ± 15.2%. In the middle of the peak growing seasons, the ecosystem water sensitivity was weak, and thus, the resistance to drought was strong, which resulted in high ecosystem stability. At the beginning and end of the peak growing seasons, the ecosystem stability was relatively weak. Ecosystem stability was positively related to the corresponding multiyear average soil water content (SWC
ave
). However, drought occurring during high SWC
ave
periods led to larger reductions in GPP, which indicated that the inhibitory effects of drought on ecosystems were more dependent on the occurrence time of droughts than on ecosystem stability.
Size-dependent melting of onion-like fullerenic carbons: a molecular dynamics and machine learning study
Authors: Fu Ran , Xu Yihua , Qiao Shi , Liu Yisi , Lin Yanwen , Li Yang , Zhang Zhisen , Wu Jianyang 
Published: August 2022

Abstract
The melting thermodynamic characteristics of 2- to 20-layered onion-like fullerenes (OLF
n
) (C60@C240 to C60@···@C6000···@C24000) are comprehensively explored using first-principles-based ReaxFF atomistic simulations and random forest machine learning (RF ML). It is revealed that OLF
n
shows lower thermal stability than the counterparts of single-walled fullerenes (SWF
n
). The melting point of SWF
n
increases monotonically with increasing size, whereas for OLF
n
, an unusual size-dependent melting point is observed; OLF
n
with intermediate size shows the highest melting point. For small OLF
n
, the melting occurs from the inner to the outer, whereas for large OLF
n
, it nucleates from the inner to the outer and to intermediate fullerenes. The melting and erosion behaviors of both SWF
n
and OLF
n
are mainly characterized by the nucleation of non-hexagons, nanovoids, carbon chains and emission of C2. RF ML model is developed to predict the melting points of both SWF
n
and OLF
n
. Moreover, the analysis of the feature importance reveals that the Stone-Wales transformation is a critical pathway in the melting of SWF
n
and OLF
n
. This study provides new insights and perspectives into the thermodynamics and pyrolysis chemistry of fullerenic carbons, and also may shed some lights onto the understanding of thermally-induced erosion of carbon-based resources and spacecraft materials.
Visual perception of surface roughness via maximum variance direction of image patches
Authors: Zou Lingyun , Jiang Jun , Deng Gaoxu , Wu Shiqian 
Published: August 2022

Abstract
Most existing visual roughness perception algorithms are pixel-wised operations, which lead to unstable roughness measurements. To address this problem, a novel visual roughness perception in the maximum variance direction of image patches is proposed in this article. Specifically, each patch is assumed to be a point in a multi-dimensional Euclidean space. To improve the signal-to-noise ratio of roughness, all points are projected onto its maximum variance direction based on principal component analysis. In this direction, the variance of these points is characterized as roughness. A new roughness metric dataset is constructed by scanned images of sandpapers with different mesh sizes to verify the effectiveness of the proposed algorithm. Experiments on the dataset show the proposed method outperforms many computer vision-based methods, such as the gray-level co-occurrence matrix approach and the

G

a

approach.
Research on a pavement pothole extraction method based on vehicle-borne continuous laser scanning point cloud
Authors: Rufei Liu , Jiben Yang , Hongwei Ren , Bori Cong , Chenhao Chang 
Published: August 2022

Abstract
Automatic detection and rapid extraction of condition characteristics of pavement potholes provide important support for road health monitoring and maintenance. In this paper, a method of extracting pavement potholes in vehicle-borne continuous laser point cloud combined with two-dimensional and three-dimensional analysis is proposed. This method mainly includes three parts: Firstly, point cloud data preprocessing is carried out to remove non-road point cloud and road noise points; then the transverse and longitudinal sections of the road are extracted according to the scanning line index of the laser point cloud. The Douglas–Pucker operator is used to analyse the profile contour characteristics, and the integral invariant operator is used to identify the initial feature points of the pothole; finally, the local datum surface of the pavement is constructed by fitting, and the continuous depth image of the pavement is generated. The active contour model operator is used to accurately extract the pothole boundary based on the local depth information, and geometric information such as the depth and area of the pothole is obtained. Selecting some road point cloud data for experiments, the results show that the pothole feature point extraction method in this paper is relatively robust, the extraction precision rate reaches 86.1%, and the recall rate reaches 91.2%. By generating a local depth image for precise extraction of the pothole boundary, it can effectively solve the problem of inaccurate extraction of the pothole boundary based on discrete point clouds. Compared with the manual measurement results, the relative error of the area is less than 7%, and the relative error of the depth is less than 6%, which proves the effectiveness of this method.
Shape reconfiguration and functional self-healing of thermadapt shape memory epoxy vitrimers by exchange reaction of disulfide bonds
Authors: Li Ben , Zhu Guangming , Hao Yujia , Ren Tianning 
Published: August 2022

Abstract
Epoxy-based shape memory materials still face many challenges from preparation to application. Designing dynamic covalent bonds into the cross-linked network of epoxy can bring many new properties to them, which is expected to solve some of the problems faced. In this paper, epoxy vitrimers with different contents of exchangeable disulfide bonds were synthesized by the polymerization of hydrogenated epoxy resins with diacids containing dynamic disulfide bonds. The effect of disulfide bond content on the properties of epoxy vitrimers was systematically studied. By activating the exchange reaction of disulfide bonds, the permanent shape of epoxy vitrimers can be reconfigured, even from two to three dimensions. The time required for reconfiguring is affected by the content of disulfide bonds, the more disulfide bonds, the shorter the time required. The epoxy vitrimers with more content of disulfide bonds were found to have lower recovery ratio loss after the same shape memory cycle by thermal bending experiments. More importantly, the epoxy vitrimers with more content of disulfide bonds also exhibited better functional self-healing properties. The decreased recovery ratio can be healed by periodic heat treatment, thus ensuring that the epoxy vitrimers perform more shape memory cycles and maintain a high shape recovery ratio. These experimental results will serve as a basis for expanding the range of applications and prolonging the service life of epoxy-based shape memory materials.
Protecting quantum entanglement in thermal reservoir by detuning
Authors: Zhang Chi , Yang Jianhe 
Published: August 2022

Abstract
In this work, the quantum entanglement dynamics of a two-atom system in the thermal reservoir is investigated. An analytical solution of the single atom in the thermal reservoir and the expression of the quantum entanglement of the two-atom system in the thermal reservoir are obtained by the Markovian master equation method. The results showed that the nonzero temperature leads to sudden death of entanglement under the weak coupling limit. The higher the temperature, the faster the decay of entanglement. In particular, the detuning and the smaller spectrum width in the weak atom-reservoir coupling regime can effectively protect the quantum entanglement of the two-atom system in the thermal reservoir under the weak atom-reservoir coupling regime. The corresponding physical explanation is given by the entropy production rare.
Field-level inference of galaxy intrinsic alignment from the SDSS-III BOSS survey
Authors: Tsaprazi Eleni , Nguyen Nhat-Minh , Jasche Jens , Schmidt Fabian , Lavaux Guilhem 
Published: August 2022

Abstract
As a large-scale overdensity collapses, it affects the orientation and shape of galaxies that form, by exerting tidal shear along their axes. Therefore, the shapes of elliptical galaxies align with the tidal field of cosmic structures. This intrinsic alignment provides insights into galaxy formation and the primordial universe, complements late-time cosmological probes and constitutes a significant systematic effect for weak gravitational lensing observations. In the present study, we provide constraints on the linear alignment model using a fully Bayesian field-level approach, using galaxy shape measurements from the SDSS-III BOSS LOWZ sample and three-dimensional tidal fields constrained with the LOWZ and CMASS galaxy samples of the SDSS-III BOSS survey. We find 4σ evidence of intrinsic alignment, with an amplitude of AI
= 2.9 ± 0.7 at 20 Mpch.