Miracle-dz/UniFAR-FTUs huggingface dataset:
Physical and chemical structure of high-mass star-forming regions

Aims. Current star formation research centers the characterization of the physical and chemical properties of massive stars, which are in the process of formation, at the spatial resolution of individual high-mass cores. Methods. We use sub-arcsecond resolution (~0.′′4) observations with the NOrthern Extended Millimeter Array at 1.37 mm to study the dust emission and molecular gas of 18 high-mass star-forming regions. With distances in the range of 0.7−5.5 kpc, this corresponds to spatial scales down to 300−2300 au that are resolved by our observations. We combined the derived physical and chemical properties of individual cores in these regions to estimate their ages. The temperature structures of these regions are determined by fitting the H2CO and CH3CN line emission. The density profiles are inferred from the 1.37 mm continuum visibilities. The column densities of 11 different species are determined by fitting the emission lines with XCLASS. Results. Within the 18 observed regions, we identified 22 individual cores with associated 1.37 mm continuum emission and with a radially decreasing temperature profile. We find an average temperature power-law index of q = 0.4 ± 0.1 and an average density power-law index of p = 2.0 ± 0.2 on scales that are on the order of several 1000 au. Comparing these results with values of p derived from the literature presumes that the density profiles remain unchanged from clump to core scales. The column densities relative to N(C18O) between pairs of dense gas tracers show tight correlations. We applied the physical-chemical model MUlti Stage ChemicaL codE to the derived column densities of each core and find a mean chemical age of ~60 000 yr and an age spread of 20 000−100 000 yr. With this paper, we release all data products of the CORE project. Conclusions. The CORE sample reveals well-constrained density and temperature power-law distributions. Furthermore, we characterized a large variety in molecular richness that can be explained by an age spread that is then confirmed by our physical-chemical modeling. The hot molecular cores show the greatest number of emission lines, but we also find evolved cores at an evolutionary stage in which most molecules are destroyed and, thus, the spectra appear line-poor once again.
A Comprehensive Study on Deep Learning-Based Methods for Sign Language Recognition

In this paper, a comparative experimental assessment of computer vision-based methods for sign language recognition is conducted. By implementing the most recent deep neural network methods in this field, a thorough evaluation on multiple publicly available datasets is performed. The aim of the present study is to provide insights on sign language recognition, focusing on mapping non-segmented video streams to glosses. For this task, two new sequence training criteria, known from the fields of speech and scene text recognition, are introduced. Furthermore, a plethora of pretraining schemes is thoroughly discussed. Finally, a new RGB+D dataset for the Greek sign language is created. To the best of our knowledge, this is the first sign language dataset where three annotation levels are provided (individual gloss, sentence and spoken language) for the same set of video captures.
Verification of phased Dicke states

Dicke states are typical examples of quantum states with genuine multipartite entanglement. They are valuable resources in many quantum information processing tasks, including multiparty quantum communication and quantum metrology. Phased Dicke states are a generalization of Dicke states and include antisymmetric basis states as a special example. These states are useful in atomic and molecular physics besides quantum information processing. Here we propose practical and efficient protocols based on adaptive local projective measurements for verifying all phased Dicke states, including $W$ states and qudit Dicke states. To verify any $n$-partite phased Dicke state within infidelity $\ensuremath{\epsilon}$ and significance level $\ensuremath{\delta}$, the number of tests required is only $O(n{\ensuremath{\epsilon}}^{\ensuremath{-}1}ln{\ensuremath{\delta}}^{\ensuremath{-}1})$, which is linear in $n$ and is exponentially more efficient than traditional tomographic approaches. In the case of $W$ states, the number of tests can be further reduced to $O(\sqrt{n}\phantom{\rule{0.16em}{0ex}}{\ensuremath{\epsilon}}^{\ensuremath{-}1}ln{\ensuremath{\delta}}^{\ensuremath{-}1})$. Moreover, we construct an optimal protocol for any antisymmetric basis state; the number of tests required decreases (rather than increases) monotonically with $n$. This is the only optimal protocol known for multipartite nonstabilizer states.
The Fractional Derivative of the Dirac Delta Function and Additional Results on the Inverse Laplace Transform of Irrational Functions

Motivated from studies on anomalous relaxation and diffusion, we show that the memory function M(t) of complex materials, that their creep compliance follows a power law, J(t)∼tq with q∈R+, is proportional to the fractional derivative of the Dirac delta function, dqδ(t−0)dtq with q∈R+. This leads to the finding that the inverse Laplace transform of sq for any q∈R+ is the fractional derivative of the Dirac delta function, dqδ(t−0)dtq. This result, in association with the convolution theorem, makes possible the calculation of the inverse Laplace transform of sqsα∓λ where α<q∈R+, which is the fractional derivative of order q of the Rabotnov function εα−1(±λ,t)=tα−1Eα,α(±λtα). The fractional derivative of order q∈R+ of the Rabotnov function, εα−1(±λ,t) produces singularities that are extracted with a finite number of fractional derivatives of the Dirac delta function depending on the strength of q in association with the recurrence formula of the two-parameter Mittag–Leffler function.
Modeling the nonlinear aeroacoustic response of a harmonically forced side branch aperture under turbulent grazing flow

The response of a side branch aperture to harmonic forcing is a key element of the feedback loop describing flow-induced aeroacoustic instability in deep cavities. We derive and validate two physics-based models which, after calibration at a given condition, predict the influence of frequency, mean flow speed, and acoustic pressure amplitude on the response. Notably, these low-order models enable robust analytical amplitude predictions of self-sustained oscillations in deep cavities under turbulent grazing flow
Indoor PM2.5 and its morphology in a naturally ventilated office in Xi'an, China

ABSTRACT This study aims to investigate the relationships of sample, morphology, and mineralogy with indoor and outdoor PM2.5 during a heating period and a nonheating period. Indoor (a naturally ventilated office) and outdoor (adjacent courtyard) PM2.5 concentrations were continuously monitored in Xi'an, China from June 1, 2015 to January 7, 2016. The average indoor and outdoor PM2.5 concentrations during the heating period were 169 and 224 μg/m3 respectively, whereas the corresponding PM2.5 for the nonheating episode were 59 and 66 μg/m3. The indoor/outdoor ratio and infiltration factor revealed that PM2.5 had primarily outdoor sources. Morphology, elemental composition, and mineralogy of PM2.5 collected indoors and outdoors were studied using scanning electron microscopy coupled with energy dispersive spectrometry (SEM-EDS) and X-ray diffraction (XRD). The SEM micrograph of PM2.5 collected during the heating period was different from that collected during the nonheating period both indoors and outdoors. EDS spectra indicated that C- and O-rich particles dominated over other elements regardless of the sampling period or place and the indoor PM2.5 consists mainly of earth crustal materials. Based on the XRD analysis, indoor PM2.5 was mostly made up of amorphous compounds while outdoor PM2.5 contained some crystalline materials such as quartz, hematite, and calcium carbonate.
Stochastic Model of Energy-Transfer Processes Among Rare-Earth Ions. Example of Al2O3:Tm3+

Energy-transfer processes strongly affect the performance of lanthanide-doped photonic devices. In this work, we introduce a simple stochastic model of energy-transfer processes and successfully apply it to the example of cross-relaxation (CR) and energy-transfer upconversion (ETU) in amorphous Al2O3:Tm3+ waveguides on silicon intended for lasers operating at ∼2 μm. The stochastic model is based on the rate-equation formalism and considers two spectroscopically distinct ion classes, namely single ions and ions with neighbors (pairs and clusters), with the corresponding ion fractions being dependent on the doping concentration. We prove that a more accurate description of the luminescence properties of amorphous Al2O3:Tm3+ is obtained when accounting for the presence of these distinct ion classes. Based on the developed model, we derive microscopic CR and ETU parameters of CCR = 5.83 × 10–38 cm6 s–1, CETU1 = 0.93 × 10–40 cm6 s–1, and CETU2 = 7.81 × 10–40 cm6 s–1, and determine the laser quantum efficiency .
Localization transition in the discrete nonlinear Schrödinger equation: ensembles inequivalence and negative temperatures

We present a detailed account of a first-order localization transition in the discrete nonlinear Schrödinger equation, where the localized phase is associated to the high energy region in parameter space. We show that, due to ensemble inequivalence, this phase is thermodynamically stable only in the microcanonical ensemble. In particular, we obtain an explicit expression of the microcanonical entropy close to the transition line, located at infinite temperature. This task is accomplished making use of large-deviation techniques, that allow us to compute, in the limit of large system size, also the subleading corrections to the microcanonical entropy. These subleading terms are crucial ingredients to account for the first-order mechanism of the transition, to compute its order parameter and to predict the existence of negative temperatures in the localized phase. All of these features can be viewed as signatures of a thermodynamic phase where the translational symmetry is broken spontaneously due to a condensation mechanism yielding energy fluctuations far away from equipartition: actually they prefer to participate in the formation of nonlinear localized excitations (breathers), typically containing a macroscopic fraction of the total energy.
Evolution of disc thickness in simulated high-redshift galaxies

We study the growth of stellar discs of Milky Way-sized galaxies using a suite of cosmological simulations. We calculate the half-mass axis lengths and axis ratios of stellar populations split by age in galaxies with stellar mass $M_{*}=10^7\! -\! 10^{10}\, \mathrm{M}_{\odot }$ at redshifts z > 1.5. We find that in our simulations stars always form in relatively thin discs, and at ages below 100 Myr are contained within half-mass height z1/2 ∼ 0.1 kpc and short-to-long axial ratio z1/2/x1/2 ∼ 0.15. Disc thickness increases with the age of stellar population, reaching median z1/2 ∼ 0.8 kpc and z1/2/x1/2 ∼ 0.6 for stars older than 500 Myr. We trace the same group of stars over the simulation snapshots and show explicitly that their intrinsic shape grows more spheroidal over time. We identify a new mechanism that contributes to the observed disc thickness: rapid changes in the orientation of the galactic plane mix the configuration of young stars. The frequently mentioned ‘upside-down’ formation scenario of galactic discs, which posits that young stars form in already thick discs at high redshift, may be missing this additional mechanism of quick disc inflation. The actual formation of stars within a fairly thin plane is consistent with the correspondingly flat configuration of dense molecular gas that fuels star formation.
Discontinuous collocation methods and gravitational self-force applications

Numerical simulations of extreme mass ratio inspirals, the most important sources for the LISA detector, face several computational challenges. We present a new approach to evolving partial differential equations occurring in black hole perturbation theory and calculations of the self-force acting on point particles orbiting supermassive black holes. Such equations are distributionally sourced, and standard numerical methods, such as finite-difference or spectral methods, face difficulties associated with approximating discontinuous functions. However, in the self-force problem we typically have access to full a priori information about the local structure of the discontinuity at the particle. Using this information, we show that high-order accuracy can be recovered by adding to the Lagrange interpolation formula a linear combination of certain jump amplitudes. We construct discontinuous spatial and temporal discretizations by operating on the corrected Lagrange formula. In a method-of-lines framework, this provides a simple and efficient method of solving time-dependent partial differential equations, without loss of accuracy near moving singularities or discontinuities. This method is well-suited for the problem of time-domain reconstruction of the metric perturbation via the Teukolsky or Regge–Wheeler–Zerilli formalisms. Parallel implementations on modern CPU and GPU architectures are discussed.
From hard spheres to hard-core spins

A system of hard spheres exhibits physics that is controlled only by their density. This comes about because the interaction energy is either infinite or zero, so all allowed configurations have exactly the same energy. The low-density phase is liquid, while the high-density phase is crystalline, an example of ``order by disorder'' as it is driven purely by entropic considerations. Here we study a family of hard spin models, which we call hard-core spin models, where we replace the translational degrees of freedom of hard spheres with the orientational degrees of freedom of lattice spins. Their hard-core interaction serves analogously to divide configurations of the many spin system into allowed and disallowed sectors. We present detailed results on the square lattice in $d=2$ for a set of models with ${\mathbb{Z}}_{n}$ symmetry, which generalize Potts models, and their $\text{U}(1)$ limits, for ferromagnetic and antiferromagnetic senses of the interaction, which we refer to as exclusion and inclusion models. As the exclusion and inclusion angles are varied, we find a Kosterlitz-Thouless phase transition between a disordered phase and an ordered phase with quasi-long-ranged order, which is the form order by disorder takes in these systems. These results follow from a set of height representations, an ergodic cluster algorithm, and transfer matrix calculations.
Quantum jump Monte Carlo approach simplified: Abelian symmetries

We consider Markovian dynamics of a ﬁnitely dimensional open quantum system featuring a weak unitary symmetry, i.e., when the action of a unitary symmetry on the space of density matrices commutes with the master operator governing the dynamics. We show how to encode the weak symmetry in quantum stochastic dynamics of the system by constructing a weakly symmetric representation of the master operator: a symmetric Hamiltonian, and jump operators connecting only the symmetry eigenspaces with a ﬁxed eigenvalue ratio. In turn, this representation simpliﬁes both the construction of the master operator as well as quantum jump Monte Carlo simulations, where, for a symmetric initial state, stochastic trajectories of the system state are supported within a single symmetry eigenspace at a time, which is changed only by the action of an asymmetric jump operator. Our results generalize directly to the case of multiple Abelian weak symmetries.
On the Stickiness of CO2 and H2O Ice Particles

Laboratory experiments revealed that CO2 ice particles stick less efficiently than H2O ice particles, and there is an order of magnitude difference in the threshold velocity for sticking. However, the surface energies and elastic moduli of CO2 and H2O ices are comparable, and the reason why CO2 ice particles were poorly sticky compared to H2O ice particles was unclear. Here we investigate the effects of viscoelastic dissipation on the threshold velocity for sticking of ice particles using the viscoelastic contact model derived by Krijt et al. We find that the threshold velocity for the sticking of CO2 ice particles reported in experimental studies is comparable to that predicted for perfectly elastic spheres. In contrast, the threshold velocity for the sticking of H2O ice particles is an order of magnitude higher than that predicted for perfectly elastic spheres. Therefore, we conclude that the large difference in stickiness between CO2 and H2O ice particles would mainly originate from the difference in the strength of viscoelastic dissipation, which is controlled by the viscoelastic relaxation time.
Semiconductor Bloch-equations formalism: Derivation and application to high-harmonic generation from Dirac fermions

We rederive the semiconductor Bloch equations emphasizing the close link to the Berry connection. Our rigorous derivation reveals the existence of two further contributions to the current, in addition to the frequently considered intraband and polarization-related interband terms. The extra contributions become sizable in situations with strong dephasing or when the dipole-matrix elements are strongly wave-number dependent. We apply the formalism to high-harmonic generation for a Dirac metal. The extra terms add to the frequency-dependent emission intensity (high-harmonic spectrum) significantly at certain frequencies changing the total signal up to a factor of 10.
High-resolution optical-to-SAR image registration using mutual information and SPSA optimisation

The high-resolution optical and synthetic aperture radar (SAR) images are widely used in many remote sensing application areas such as image fusion and change detection where image registration is a fundamental step. The latest high-resolution optical and SAR satellites and airborne systems provide geometrically corrected images which do not contain global deformations. Though the images do not have global differences, still, registration differences exist between these optical and SAR images. These registration differences should be minimised through an automatic registration method before using the images for the aforementioned applications. However, an automatic optical-to-SAR image registration is a challenging task due to the presence of signiﬁcant nonlinear intensity differences as well as local geometric distortions between the images. In order to solve these problems, an automatic optical-to-SAR image registration method is proposed which can effectively handle the registration differences between the globally corrected high-resolution images. In the proposed method, initially, a coarse registration is performed by using a discrete simultaneous perturbation stochastic approximation (SPSA) optimisation. Then, a smooth continuous SPSA optimisation is utilised for the ﬁne registration of the images. Experiments are performed on six sets of high-resolution optical-SAR image pairs and the results show the effectiveness of the proposed method.
The Prospective Epidemiological Research Studies in IrAN (PERSIAN) Birth Cohort protocol: rationale, design and methodology

Background: Birth cohorts are essential for developing evidence-based policies and advancing knowledge on different aspects of the concept of developmental origins of health and diseases (DOHaD). The Prospective Epidemiological Research Studies in IrAN (PERSIAN) is a multicentre cohort in Iran. It is one of the pioneers of DOHaD research in the Middle East and North Africa (MENA) region. This profile provides a brief overview of this birth cohort, focusing on the objectives and design of the study. The main objective of this birth cohort is to evaluate the associations of socio-economic characteristics, lifestyle, diet, environmental exposures and epigenetic factors with outcomes of: pregnancy; mother and child mental and physical health and well-being; child neurodevelopment; and the establishment of chronic disease risk factors.Methods: The enrolment of PERSIAN Birth Cohort participants is currently ongoing in five Iranian cities (Isfahan, Yazd, Semnan, Sari and Rafsanjan). We plan to recruit 15,000 mother–offspring pairs, and to follow them for at least ten years. Data collection consists of three consecutive phases: (1) periconception until birth; (2) infancy (0–2 years); and (3) childhood (3–11 years). We are collecting data on both ‘determinants of health’ and ‘health outcomes’. In addition to questionnaires and physical examination, various biological samples, including blood, urine, hair, nail, cord blood and breastmilk are being collected. Growth and neurodevelopment of children will be monitored. Appropriate data analysis schemes will be employed to assess the role of early life factors in health and disease that would facilitate international comparisons.
Electrochemical Polymerization of

Polymer thin films are prepared by electrochemical polymerization of 6-(N-allyl-1,1,2,2-tetrahydro- perfluorodecyl)amino-1,3,5-triazine-2,4-dithiol monosodium on an aluminum plate. The steric and chemical structures of films are characterized by optical ellipsometry, contact angle goniometry, Fourier transform infrared spectroscopy (FT-IR) and impedance spectroscopy. Polymer film thickness and potential applied to the films during electrochemical polymerization, a measure of packing density, increase proportionally to the square root of electrochemical polymer- ization time following a parabolic law. From FT-IR spectra of the polymer films formed on aluminum plates, only the C-F stretching vibration peak of CF3- groups at 1345 cm � 1 is observed, indicating extremely oriented polymer thin film. C1s, N1s and S2p peaks in the XPS spectra indicate that the chemical structure of polymer thin film is poly(6- (N-allyl-1,1,2,2-tetrahydroperfluorodecyl)amino-1,3,5-triazine-2,4-disulfide) (PATP) and allyl, tetrahydroperfluorodec- yl amino chain axes are perpendicular to the surface, but the triazine ring is aligned parallel to the surface. The contact angle of polymer thin films was 123 � , on which a top layer thought to be composed of CF3- groups exists. Polymer films on aluminum plates were used to produce parallel plate capacitors having capacitances of 1.33 to 2.06 mF/cm 2 . The dielectric constants of polymer films were calculated to range from 142 to 175, the highest reported for organic dielec- trics to date. (doi:10.1295/polymj.38.484)