bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ground-based visible spectroscopy of asteroids to support the development of an unsupervisedGaiaasteroid taxonomy
Authors: Cellino A. , Bendjoya Ph. , Delbo’ M. , Galluccio L. , Gayon-Markt J. , Tanga P. , Tedesco E. F. 
Published: August 2020

Context.TheGaiamission of the European Space Agency is measuring reflectance spectra of a number to the order of 105small Solar System objects. A first sample will be published in theGaiaData Release scheduled for 2021.Aims.The aim of our work was to test the procedure developed to obtain taxonomic classifications for asteroids based only onGaiaspectroscopic data.Methods.We used asteroid spectra obtained using the DOLORES (Device Optimised for the LOw RESolution) instrument, a low-resolution spectrograph and camera installed at the Nasmyth B focus of the Telescopio NazionaleGalileo. Because these spectra have a higher spectral resolution than that typical of theGaiaspectra, we resampled them to more closely match the expectedGaiaspectral resolution. We then developed a cloning algorithm to build a database of asteroid spectra belonging to a variety of taxonomic classes, starting from a set of 33 prototypes chosen from the 50 asteroids in our observing campaign. We used them to generate a simulated population of 10 000 representative asteroid spectra and employed them as the input to the algorithm for taxonomic classification developed to analyzeGaiaasteroid spectra.Results.Using the simulated population of 10 000 representative asteroid spectra in the algorithm to be used to produce theGaiaasteroid taxonomy at the end of the mission, we found 12 distinct taxonomic classes. Two of them, with 53% of the sample, are dominant. At the other extreme are three classes each with <1% of the sample, and these consist of the previously known rare classes A, D/Ld, and V; 99.1% of the simulated population fall into a single class.Conclusions.We demonstrated the robustness of our algorithm for taxonomic classification by using a sample of simulated asteroid spectra fully representative of what is expected to be in theGaiaspectroscopic data catalogue for asteroids. Increasingly larger data sets will become available as soon as they are published in the futureGaiadata releases, with the next one coming in 2021. This will be exploited to develop a correspondingly improved taxonomy, likely with minor tweaks to the algorithm described here, as suggested by the results of this preliminary analysis.
Topologically projective, injective and flat modules of harmonic analysis
Authors: Nemesh N. T. 
Published: August 2020

Abstract
We study homologically trivial modules of harmonic analysis on a locally compact group

. For

- and

-modules

,

and

we give criteria for metric and topological projectivity, injectivity and flatness. In most cases, modules with these properties must be finite-dimensional.
Bibliography: 18 titles.
Two purity theorems and the Grothendieck-Serre conjecture concerning principal

-bundles
Authors: Panin I. A. 
Published: August 2020

Abstract
The main results of the paper are two purity theorems for reductive group schemes over regular local rings containing a field. Using these two theorems a well-known Grothendieck-Serre conjecture on principal bundles is reduced to the simply-connected case. We point out that the mentioned reduction is one of the major steps in the proof of the conjecture that the author published in another work.
Bibliography: 25 titles.
Expanding the comparative view
Authors: Solleveld Floris 
Published: August 2020

SummaryWilhelm von Humboldt’sÜber die Kawi-Sprache auf der Insel Javacan be seen as the first comparative grammar of non-Indo-European languages. While Humboldt’s practice of collecting and re-assembling linguistic information has been documented extensively in the Berlin Academy edition of hisSchriften zur Sprachwissenschaft,this article puts his work in perspective by tracing it back to its sources and treating it as part of a wider parallel process of expanding the comparative view. In three sections, this article discusses (1) the research agendas of the three British colonial scholars upon whose works Humboldt drew for Malayan languages; (2) to which extent his Polynesian language material was ‘rawer’ than these compendia; and (3) how he reworked this material into a comparative Malayo-Polynesian grammar. Finally, a comparison is drawn with the work of his assistant and continuator Eduard Buschmann, and with Horatio Hale’s slightly later survey of the languages of the Pacific.
L’Hypothèse d’Isochronie Syllabique Initiale appliquée au français L2
Authors: Engel Hugues 
Published: August 2020

RésuméL’objectif principal de cette étude pilote est de tester expérimentalement ce que nous appelons l’Hypothèse d’Isochronie Syllabique Initiale. Selon cette hypothèse, les apprenants de L2 passent par une phase initiale pendant laquelle leurs productions orales présentent les caractéristiques rythmiques des langues dites à isochronie syllabique (telles que l’espagnol et le français). Pour cela, nous analysons des récits oraux d’apprenantes débutantes de français ayant le suédois pour langue maternelle (n = 6). Ces productions sont comparées à celles d’un groupe de locutrices natives du français (n = 6) et d’un groupe de locutrices natives du suédois (n = 6). Les caractéristiques rythmiques des récits en français L2, français L1 et suédois L1 sont étudiées à partir de deux mesures acoustiques, notamment le coefficient de variation de la durée syllabique, dont l’utilisation est préconisée parPatel (2008)pour déterminer si une langue est de type accentuel ou syllabique. Les mesures acoustiques employées permettent de confirmer que le français et le suédois appartiennent à des familles rythmiques distinctes. Les résultats de l’étude vont cependant à l’encontre de l’Hypothèse d’Isochronie Syllabique Initiale.
Word formation in the earliest stages of L2 Polish
Authors: Saturno Jacopo 
Published: August 2020

AbstractThis paper examines word formation strategies in initial SLA, with particular regard to the implicit processing of the distributional properties of the input. Learners with various L1s and no experience of the target language (n=163) took a 14-hour L2 Polish course under controlled input conditions. In an oral production task, these learners were asked to describe properties of human referents who had never appeared in the input by stating their nationality or profession. In their output, the learners most often referred to the target referents by attaching a-k(-)sound cluster to a lexical morpheme borrowed from a known language. Quantitative analysis shows that indeed, within the input considered, the same-k(-)cluster is characteristic of most words referring to human entities. The study concludes that learners can analyse the morphological structure of target words even after minimal exposure to the input, identifying at first the derivational formants characterised by the strongest association to the intended meaning.
Development of a plasma electroacoustic actuator for active noise control applications
Authors: Sergeev S , Lissek H , Howling A , Furno I , Plyushchev G , Leyland P 
Published: August 2020

Abstract
Conventional loudspeakers generate sound through the vibration of a diaphragm, attached to a rigid frame through elastic suspensions. Although such construction is satisfactory for sound diffusion in steady environments, it is likely to fail in harsh conditions, which is often the case for active noise control applications. Plasma-based actuators appear to be a promising alternative since they do not involve any fragile moving parts. In this paper, a positive corona discharge actuator in a wire-to-mesh geometry is proposed in the perspective of active noise control applications, as it is capable of generating sufficient sound pressure levels with limited signal distortion. The study introduces analytical and numerical models aiming at characterizing the sound field generated by the corona discharge actuator. The numerical simulation can facilitate the designing of such transducers. The acoustic power of the experimental prototype is increased through the optimization of emitter wires arrangement. The comparison of analytical model and numerical simulation with the experiment is presented. The analytical model successively describes the low frequency sound pressure field, while the numerical simulation is valid in the broader frequency range.
Phase-field study on the effect of initial particle aggregation on the transient coarsening behaviors
Authors: Wang Yujian , Li Junjie , Zhang Lei , Wang Zhijun , Wang Jincheng 
Published: August 2020

Abstract
The transient coarsening behavior of poly-disperse particles that aggregate into clusters was studied using a phase-field model in two dimensions. The effects of two characters of the cluster, i.e., particle number N
c and particle density ρ
c in a cluster, on the kinetics of transient coarsening are systematically investigated. The transient coarsening experiences two stages: the merging of multiple particles in a cluster into a single particle and further evolution towards the steady state. The evolutions of the scaled particle size distribution and the coarsening rate are non-monotonic during the transient stage. The length of the transient stage for the system with uniform cluster size increases with N
c but is insensitive to ρ
c. Reducing the cluster size homogenization can shorten the transient stage. Moreover, if the coarsening time is scaled by the moment at which multiple particles in all clusters complete the merging, the temporal evolutions of particle radius and particle size distribution are almost uniform for systems with different N
c. This uniform relationship can be used to predict the long transient stage for the system with large N
c, which cannot be directly obtained with limited simulation time.
Modulation of the transport properties of metal/MoS2 interfaces using BN-graphene lateral tunneling layers
Authors: Guo Rui , Su Jie , Zhang Pengliang , He Fuchao , Lin Zhenhua , Zhang Jincheng , Chang Jingjing , Hao Yue 
Published: August 2020

Abstract
Modulating the n- and p-type interfacial charge transport properties of the metal–semiconductor interface is vital to realizing high performance two-dimensional material nanodevices and is still a significant challenge. Here, a boron nitride (BN)-graphene lateral heterostructure (LH) was used as the interfacial tunneling layer to control the Schottky barrier, Fermi level pinning and charge injection efficiency of the metal–MoS2 interface. The BN-graphene LH with graphene-N junction structure decreased the n-type vertical Schottky barrier and enhanced the interfacial tunneling probability, while the graphene-B junction structure decreased the p-type vertical Schottky barrier. Consequently, the n-type Au/LH–MoS2 interface with Ohmic character and high tunneling probability (∼0.242) and the p-type vertical Schottky barrier of about 0.20 eV for the Pt/LH–MoS2 interface were achieved. Compared to other reported BN or graphene tunneling layers, such a BN-graphene LH tunneling layer not only suppressed the charge scattering from the metal electrode to the MoS2 layer and the Fermi level pinning effect, but also reduced the contact resistance between metal electrode and tunneling layer. The underlying mechanisms were revealed to be due to the charge transfer, orbitals and interfacial dipole. This work improves the current understanding of the metal–MoS2 interface and proposes a new way to overcome the current severe contact issues for future nanoelectronic and optoelectronic applications.
An unsupervised deep learning method for multi-coil cine MRI
Authors: Ke Ziwen , Cheng Jing , Ying Leslie , Zheng Hairong , Zhu Yanjie , Liang Dong 
Published: August 2020

Abstract
Deep learning has achieved good success in cardiac magnetic resonance imaging (MRI) reconstruction, in which convolutional neural networks (CNNs) learn a mapping from the undersampled k-space to the fully sampled images. Although these deep learning methods can improve the reconstruction quality compared with iterative methods without requiring complex parameter selection or lengthy reconstruction time, the following issues still need to be addressed: 1) all these methods are based on big data and require a large amount of fully sampled MRI data, which is always difficult to obtain for cardiac MRI; 2) the effect of coil correlation on reconstruction in deep learning methods for dynamic MR imaging has never been studied. In this paper, we propose an unsupervised deep learning method for multi-coil cine MRI via a time-interleaved sampling strategy. Specifically, a time-interleaved acquisition scheme is utilized to build a set of fully encoded reference data by directly merging the k-space data of adjacent time frames. Then these fully encoded data can be used to train a parallel network for reconstructing images of each coil separately. Finally, the images from each coil are combined via a CNN to implicitly explore the correlations between coils. The comparisons with classic k-t FOCUSS, k-t SLR, L+S and KLR methods on in vivo datasets show that our method can achieve improved reconstruction results in an extremely short amount of time.
Radiation emission at Langmuir frequency from laser wake in longitudinally stratified plasma column
Authors: Kalmykov Serge , Elle Jennifer , Schmitt-Sody Andreas 
Published: August 2020

Abstract
Theoretical analysis shows that a small-amplitude laser wake (an electrostatic Langmuir wave), driven in a periodically stratified, cylindrical plasma column, generates a superluminal, azimuthally polarized rotational current at a Langmuir frequency. The current radiates a radially polarized (i.e. transverse magnetic) Cherenkov signal into the plasma-free space. The opening angle of the Cherenkov emission cone is defined by the spatial period of stratification. Lifetime of the laser wake, limited by wave breaking in the inhomogeneous plasma, defines the terahertz (THz) signal length. This length ranges from a few picoseconds to hundreds of picoseconds, depending on the wake amplitude, amplitude of background density modulation, and stratification period. Monochromaticity and coherence distinguishes this THz signal from the ultrashort, uncollimated, broadband signals generated by photoionization currents in plasma filaments. The efficiency of electromagnetic energy conversion, from optical to THz, reaches its peak when the drive pulse waist size is close to the column radius. The efficiency increases with an increase in the drive pulse wavelength, and reaches the maximum when the drive pulse becomes near-critical for relativistic self-focusing. Numerical examples with sub-Joule, near-infrared terawatt drive pulses demonstrate the highest conversion efficiency of the order 10−5, with the total emitted energy of several µJ, a few-hundred MV m−1 electric field at the column surface, and an MV m−1 field 10 cm away from the source.
The effect of climatic factors on nutrients in foods: evidence from a systematic map
Authors: Giulia Scarpa , Lea Berrang-Ford , Carol Zavaleta-Cortijo , Lisa Marshall , Harper Sherilee L , Elizabeth Cade Janet 
Published: August 2020

Abstract
Climate change is projected to negatively affect human health and nutrition. There is a growing literature on the effects of climatic changes on food availability, quantity, and agricultural production, but impacts on the nutritional content of foods has not been widely studied. The aim of this paper is to systematically characterise empirical literature exploring the effects of climatic drivers on macronutrients and micronutrients in foods causing malnutrition globally. 69 peer-reviewed empirical articles (excluding experimental and modelling studies) analysing the effect of climatic drivers on nutrients in foods were retrieved from Web of ScienceTM, Scopus® and PubMed® databases (2013–2019). Publication frequency and trends, and existing evidence of the extent of nutrient change associated with variation in climate-related conditions were assessed. There is relatively limited literature on associations between climate and nutrients in foods. Where it exists, only crude proxies of climate (e.g. wet/dry season) are used, with limited interrogation of the potential causal mechanisms linking climate to nutrient content. 98% of the articles showed a change in nutrient content in relation to a seasonal or meteorological variable. Most analysed the association of nutrient changes between seasons over 1–2 years, rarely over longer periods of time. Preliminary descriptive estimates point to variation in nutrient content by meteorological variability, particularly in ocean and freshwater food sources. Robust assessment of potential climate impacts on nutrient content of foods would benefit from more precise estimation of specific causal pathways and variables that mediate climate impacts on food, going beyond seasonal or crude proxies. There is need for clear articulation of how climate change might impact nutrient content given mechanisms linking meteorological and seasonal variation with nutrients. This research highlights emerging evidence that climate change may have impacts beyond agricultural productivity by affecting food nutrient content, an understudied but potentially important pathway for climate impact on global food and nutrition security.
Bulk entanglement entropy and matrices
Authors: Das Sumit R , Kaushal Anurag , Mandal Gautam , Trivedi Sandip P 
Published: August 2020

Abstract
Motivated by the Bekenstein–Hawkingformula and the area law behaviour of entanglement entropy, we propose that in any UV finite theory of quantum gravity with a smooth spacetime, the total entropy for a pure state in a co-dimension one spatial region, to leading order, is given by

S
=

A

4

G

N

, where A is the area of the co-dimension two boundary. In the context of Dp brane holography we show that for some specially chosen regions bulk entanglement can be mapped to ‘target space’ entanglement in the boundary theory. Our conjecture then leads to a precise proposal for target space entanglement in the boundary theory at strong coupling and large N. In particular, it leads to the conclusion that the target space entanglement would scale like O(N
2) which is quite plausible in a system with O(N
2) degrees of freedom. Recent numerical advances in studying the D0 brane system hold out the hope that this proposal can be tested in a precise way in the future.
General state transitions with exact resource morphisms: a unified resource-theoretic approach
Authors: Zhou Wenbin , Buscemi Francesco 
Published: August 2020

Abstract
Given a non-empty closed convex subset F of density matrices, we formulate conditions that guarantee the existence of an F-morphism (namely, a completely positive trace-preserving linear map that maps F into itself) between two arbitrarily chosen density matrices. While we allow errors in the transition, the corresponding map is required to be an exact F-morphism. Our findings, though purely geometrical, are formulated in a resource-theoretic language and provide a common framework that comprises various resource theories, including the resource theories of bipartite and multipartite entanglement, coherence, athermality, and asymmetric distinguishability. We show how, when specialized to some situations of physical interest, our general results are able to unify and extend previous analyses. We also study conditions for the existence of maximally resourceful states, defined here as density matrices from which any other one can be obtained by means of a suitable F-morphism. Moreover, we quantitatively characterize the paradigmatic tasks of optimal resource dilution and distillation, as special transitions in which one of the two endpoints is maximally resourceful.
Coaxial printing of double-layered and free-standing blood vessel analogues without ultraviolet illumination for high-volume vascularised tissue
Authors: Duong Van Thuy , Dang Thi Thao , Hwang Chang Ho , Back Sung Hoon , Koo Kyo-in 
Published: August 2020

Abstract
Human umbilical vein endothelial cells (HUVECs) and human aortic smooth muscle cells (HASMCs) were coaxially and continuously extruded without ultraviolet illumination using a microfluidic-based nozzle. Type I collagen (3 mg ml−1) containing HUVECs and a crosslinking reagent (100 mM CaCl2) were supplied as the core material. A mixture of 3 mg ml−1 of type I collagen (25%) and 1.8% weight volume−1 of sodium alginate (75%) was provided as the shell layer material surrounding the core material. The HUVECs were well proliferated at the core and reshaped into a monolayer formation along the axial direction of the scaffold. The HASMCs showed more than 90% cell viability in the shell layer. Fluorescent beads were passed through the inside channel of the scaffold with the HUVEC core and HASMC shell using an in-house connector. This double-layered scaffold showed higher angiogenesis in growth factor-free medium than the scaffold with only a HUVEC core. The HASMCs in the shell layer affected angiogenesis, extracellular matrix secretion, and outer diameter. The proposed technique could be applied to three-dimensional bioprinting for the production of high-volume vascularised tissue.
Fiber-based all-optical modulation based on two-dimensional materials
Authors: Zhang Meng , Wu Qing , Chen Hualong , Zheng Zheng , Zhang Han 
Published: August 2020

Abstract
All-optical modulation with two-dimensional (2D) layered materials are becoming an indispensable tool in a variety of applications due to their superior performance in photonics and optoelectronics. Here, we review recent progress demonstrating the application of optical modulators utilizing their nonlinear optical properties of 2D materials. We focus specially on transition metal dichalcogenides, black phosphorus, and MXenes. We discuss the fabrication and integrating procedure of the layered materials and highlight recent demonstrations of all-optical passive modulators for ultrashort pulse generation and thermo-optic switches that applied in versatile interferometers. We also conclude with an outlook exploring the future perspectives that may accelerate the practical applications in this vibrant field.
Effects and optimization of ratio of particle size grading on compaction density of calcined coke particles
Authors: Hou Wenyuan , Li Hesong , Li Mao , Cheng Benjun 
Published: August 2020

Abstract
The bulk density of the anodes affects the energy consumption and associated carbon emissions of the calcined anodes over the course of the Hall-Héroult process. The bulk density of the anode mainly depends on the compaction density of calcined coke particles. In this paper, the vibro-compacting process of calcined coke particles is simulated using discrete element method. The particle behavior during vibro-compacting process and the inter-particle contact information with different ratios of particle size grading are investigated. The effects of different ratios of particle size grading on the compaction density and microstructure are studied. The critical average diameter which can distinguish whether the compaction density meets standard requirement is first proposed and obtained. The triangular coordinate graphical is introduced to optimize the ratio of particle size grading which is different from conventional method. The results show that the larger the proportion of coarse particle and medium particle, the more large voids between particles, and the increase of fine particle can effectively fill the inter-particle gap. The critical average diameter of calcined coke particles is 2.26 mm, and average diameter less than 2.26 mm can meet the standard requirement. The optimal ratio of particle size grading is 46% for coarse particle, 12% for medium particle and 42% for fine particle.