Miracle-dz/UniFAR-FTUs huggingface dataset:
Direct versus indirect band gap emission and exciton-exciton annihilation in atomically thin molybdenum ditelluride (MoTe 2 )

We probe the room temperature photoluminescence of $N$-layer molybdenum ditelluride (MoTe$_2$) in the continuous wave (cw) regime. The photoluminescence quantum yield of monolayer MoTe$_2$ is three times larger than in bilayer MoTe$_2$ and forty times greater than in the bulk limit. Mono- and bilayer MoTe$_2$ display almost symmetric emission lines at $1.10~\rm eV$ and $1.07~\rm eV$, respectively, which predominantly arise from direct radiative recombination of the A exciton. In contrast, $N\geq3-$layer MoTe$_2$ exhibits a much reduced photoluminescence quantum yield and a broader, redshifted and seemingly bimodal photoluminescence spectrum. The low- and high-energy contributions are attributed to emission from the indirect and direct optical band gaps, respectively. Bulk MoTe$_2$ displays a broad emission line with a dominant contribution at 0.94~eV that is assigned to emission from the indirect optical band gap. As compared to related systems (such as MoS$_2$, MoSe$_2$, WS$_2$ and WSe$_2$), the smaller energy difference between the monolayer direct optical band gap and the bulk indirect optical band gap leads to a smoother increase of the photoluminescence quantum yield as $N$ decreases. In addition, we study the evolution of the photoluminescence intensity in monolayer MoTe$_2$ as a function of the exciton formation rate $W_\mathrm{abs}$ up to $3.6\times 10^{22}~\rm{cm}^{-2} s^{-1}$. The lineshape of the photoluminescence spectrum remains largely independent of $W_\mathrm{abs}$, whereas the photoluminescence intensity grows sub-linearly above $W_\mathrm{abs}\sim 10^{21}~\rm cm^{-2} s^{-1}$. This behavior is assigned to exciton-exciton annihilation and is well-captured by an elementary rate equation model.
Music Fiesta-The Recommendation System

The objective of the Music Fiesta is to provide listeners with relevant song recommendations based on their preferences and moods. Seven Indian genres are used in system implementation. The system uses a collaborative filtering approach for its music recommendation. It uses the Singular Value Decomposition algorithm as a matrix factorization technique. The system also tries to identify the mood of the listener by extracting the information about the beat of the song (tempo) and thereby recommending similar songs. As the system uses various acoustic features for the recommendation, it seeks help from the SVD algorithm to decide on the important features.
About one method of parallelization of calculations during the reconstruction of a tomographic image

A new method for solving systems of linear algebraic equations of a special type arising in solving problems of image reconstruction has been proposed. This method, due to a certain symmetry of the matrix and the choice of the voxel numeration method for two-dimensional problems, allows us to divide the initial system of algebraic equations into two independent systems, which enables us to carry out the calculation in parallel. The dimension of the matrices of the resulting systems is 4 times less than the dimension of the original matrix, and these matrices are less dispersed.
Adult numeracy skill practice by STEM and non-STEM workers in the USA: an exploration of data using latent class analysis

ABSTRACT Adult numeracy is one of the essential skill sets to navigate through numeric information-rich labour markets in general, and STEM industries in particular. Yet, relatively little is known about how numeracy skills are used in different settings in the USA. This study examined numeracy skill use patterns of STEM and non-STEM workers at work and home. Data were obtained from the 2012/2014/2017 Program for International Assessment of Adult Competencies, USA restricted-use file. Adults who were employed and aged between 25 and 65 years old (n = 5,220) were included in this study. Latent class analysis revealed four numeracy skill use patterns: non-users, non-occupational (i.e. at home) simple numeracy users, ubiquitous numeracy users, and occupational numeracy users. Additional multinomial logistic regression analysis showed that the STEM occupation was associated with a greater likelihood of being ubiquitous users than being non-occupational simple users. Results also showed that numeracy proficiency, socioeconomic statuses (i.e. educational attainment and income), as well as demographic characteristics (i.e. gender and race/ethnicity), were predictive of the numeracy skill use patterns in terms of the level of engagement and settings. Findings from this study inform policies and interventions which promote skill engagement and improvement among workers in the USA.
Experimental study of mutual information in a Maxwell Demon

We validate experimentally a fluctuation relation known as generalized Jarzynski equality (GJE) governing the work distribution in a feedback-controlled system. The feedback control is performed on a single electron box analogously to the original Szilard engine. In GJE, mutual information is treated on an equal footing with the thermodynamic work. Our results clarify the role of the mutual information in thermodynamics of irreversible processes.
A Mathematicians' View of Geometrical Unification of General Relativity and Quantum Physics

This document contains a description of physics entirely based on a geometric presentation: all of the theory is described giving only a pseudo-riemannian manifold (M, g) of dimension n > 5 for which the g tensor is, in studied domains, almost everywhere of signature (-, -, +, ., +). No object is added to this space-time, no general principle is supposed. The properties we impose to some domains of (M, g) are only simple geometric constraints, essentially based on the concept of "curvature". These geometric properties allow to define, depending on considered cases, some objects (frequently depicted by tensors) that are similar to the classical physics ones, they are however built here only from the g tensor. The links between these objects, coming from their natural definitions, give, applying standard theorems from the pseudo-riemannian geometry, all equations governing physical phenomena usually described by classical theories, including general relativity and quantum physics. The purely geometric approach introduced hear on quantum phenomena is profoundly different from the standard one. Neither Lagrangian nor Hamiltonian are used. This document ends with a quick presentation of our approach of complex quantum phenomena usually studied by quantum field theory.
SURFACE DENSITY EFFECTS IN QUENCHING: CAUSE OR EFFECT?

There are very strong observed correlations between the specific star formation rates (sSFRs) of galaxies and their mean surface mass densities, Σ, as well as other aspects of their internal structure. These strong correlations have often been taken to argue that the internal structure of a galaxy must play a major physical role, directly or indirectly, in the control of star formation. In this paper we show by means of a very simple toy model that these correlations can arise naturally without any such physical role once the observed evolution of the size–mass relation for star-forming galaxies is taken into account. In particular, the model reproduces the sharp threshold in Σ between galaxies that are star-forming and those that are quenched and the evolution of this threshold with redshift. Similarly, it produces iso-quenched-fraction contours in the fQ(m, Re) plane that are almost exactly parallel to lines of constant Σ for centrals and shallower for satellites. It does so without any dependence on quenching on size or Σ and without invoking any differences between centrals and satellites, beyond the different mass dependences of their quenching laws. The toy model also reproduces several other observations, including the sSFR gradients within galaxies and the appearance of inside-out build-up of passive galaxies. Finally, it is shown that curvature in the main-sequence sSFR–mass relation can produce curvature in the apparent B/T ratios with mass. Our analysis therefore suggests that many of the strong correlations that are observed between galaxy structure and sSFR may well be a consequence of things unrelated to quenching and should not be taken as evidence of the physical processes that drive quenching.
The singular and the 2:1 anisotropic Dunkl oscillators in the plane

Two Dunkl oscillator models are considered: one singular and the other with a 2:1 frequency ratio. These models are defined by Hamiltonians which include the reflection operators in the two variables x and y. The singular or caged Dunkl oscillator is second-order superintegrable and admits separation of variables in both Cartesian and polar coordinates. The spectrum of the Hamiltonian is obtained algebraically and the separated wavefunctions are given in the terms of Jacobi, Laguerre and generalized Hermite polynomials. The symmetry generators are constructed from the su(1,1)? > dynamical operators of the one-dimensional model and generate a cubic symmetry algebra. In terms of the symmetries responsible for the separation of variables, the symmetry algebra of the singular Dunkl oscillator is quadratic and can be identified with a special case of the Askey–Wilson AW(3) algebra with central involutions. The 2:1 anisotropic Dunkl oscillator model is also second-order superintegrable. The energies of the system are obtained algebraically, the symmetry generators are constructed using the dynamical operators and the resulting symmetry algebra is quadratic. The general system appears to admit separation of variables only in Cartesian coordinates. Special cases where separation occurs in both Cartesian and parabolic coordinates are considered. In the latter case the wavefunctions satisfy the biconfluent Heun equation and depend on a transcendental separation constant.
Analogues of Iwasawa’s $\mu = 0$ conjecture and the weak Leopoldt conjecture for a non-cyclotomic $\mathbb{Z}_2$-extension

Let $K = \mathbb{Q}(\sqrt{-q})$, where $q$ is any prime number congruent to $7$ modulo $8$, and let $\mathcal{O}$ be the ring of integers of $K$. The prime $2$ splits in $K$, say $2\mathcal{O} = \mathfrak{p} \mathfrak{p}^\ast$, and there is a unique $\mathbb{Z}_2$-extension $K_\infty$ of $K$, which is unramified outside $\mathfrak{p}$. Let $H$ be the Hilbert class field of $K$, and write $H_\infty = HK_\infty$. Let $M(H_\infty)$ be the maximal abelian $2$-extension of $H_\infty$, which is unramified outside the primes above $\mathfrak{p}$, and put $X(H_\infty) = \mathrm{Gal}(M(H_\infty)/H_\infty)$. We prove that $X(H_\infty)$ is always a finitely generated $\mathbb{Z}_2$-module, by an elliptic analogue of Sinnott's cyclotomic argument. We then use this result to prove for the first time the weak $\mathfrak{p}$-adic Leopoldt conjecture for the compositum $J_\infty$ of $K_\infty$ with arbitrary quadratic extensions $J$ of $H$. We also prove some new cases of the finite generation of the Mordell-Weil group $E(J_\infty)$ modulo torsion of certain elliptic curves $E$ with complex multiplication by $\mathcal{O}$.
Polynomial and exponential stability of $\theta$-EM approximations to a class of stochastic differential equations

Both the mean square polynomial stability and exponential stability of $\theta$ Euler-Maruyama approximation solutions of stochastic differential equations will be investigated for each $0\le\theta\le 1$ by using an auxiliary function $F$ (see the following definition (2.3)). Sufficient conditions are obtained to ensure the polynomial and exponential stability of the numerical approximations. The results in Liu et al [12] will be improved and generalized to more general cases. Several examples and non stability results are presented to support our conclusions.
Parsec-scale SiO emission in an infrared dark cloud

We present high-sensitivity 2 × 4a rcmin 2 maps of the J = 2→1 rotational lines of SiO, CO, 13 CO and C 18 O, observed towards the filamentary infrared dark cloud (IRDC) G035.39−00.33. Single-pointing spectra of the SiO J = 2→1 and J = 3→2 lines towards several regions in the filament are also reported. The SiO images reveal that SiO is widespread along the IRDC (size ≥2 pc), showing two different components: one bright and compact arising from three condensations (N, E and S) and the other weak and extended along the filament. While the first component shows broad lines (linewidths of ∼4–7 km s −1 ) in both SiO J = 2→1 and SiO J = 3→2, the second one is only detected in SiO J = 2→1 and has narrow lines (∼0.8 km s −1 ). The maps of CO and its isotopologues show that low-density filaments are intersecting the IRDC and appear to merge towards the densest portion of the cloud. This resembles the molecular structures predicted by flow-driven, shock-induced and magneticallyregulated cloud formation models. As in outflows associated with low-mass star formation, the excitation temperatures and fractional abundances of SiO towards N, E and S increase with velocity from ∼ 6t o 40 Ka nd from∼10 −10 to ≥10 −8 , respectively, over a velocity range of ∼ 7k m s −1 . Since 8 μm and 24 μm sources and/or extended 4.5 μm emission are detected in N, E and S, broad SiO is likely produced in outflows associated with high-mass protostars. The excitation temperatures and fractional abundances of the narrow SiO lines, however, are very low (∼9 K and ∼10 −11 , respectively), and consistent with the processing of interstellar grains by the passage of a shock with vs ∼ 12 km s −1 . This emission could be generated (i) by a large-scale shock, perhaps remnant of the IRDC formation process, (ii) by decelerated or recently processed gas in large-scale outflows driven by 8- and 24-μm sources or (iii) by an undetected and widespread population of lower mass protostars. High-angular-resolution observations are needed to disentangle between these three scenarios.
Multilevel Quadrature for Elliptic Parametric Partial Differential Equations in Case of Polygonal Approximations of Curved Domains

Multilevel quadrature methods for parametric operator equations such as the multilevel (quasi-) Monte Carlo method are closely related to the sparse tensor product approximation between the spatial variable and the parameter. In this article, we employ this fact and reverse the multilevel quadrature method via the sparse grid construction by applying differences of quadrature rules to finite element discretizations of increasing resolution. Besides being algorithmically more efficient if the underlying quadrature rules are nested, this way of performing the sparse tensor product approximation enables the easy use of non-nested and even adaptively refined finite element meshes. Especially, we present a rigorous error and regularity analysis of the fully discrete solution, taking into account the effect of polygonal approximations to a curved physical domain and the numerical approximation of the bilinear form. Our results facilitate the construction of efficient multilevel quadrature methods based on deterministic quadrature rules. Numerical results in three spatial dimensions are provided to illustrate the approach.
Accelerated Durability Evaluation of Emerging Cell Interconnect Technologies

In this study, we investigate the durability of four different cell interconnect technologies using three long-term accelerated stress tests. The interconnect technologies investigated in this study are: conventional five busbar, tabbed interconnect ribbons (ribbon-tabbed); 12 busbar, soldered wire interconnects (soldered wire); shingled cell interconnects attached with an electrically conductive adhesive (shingled); and laminated wire interconnects with no busbar (laminated wire). The accelerated stress tests implemented in this study are: dynamic mechanical load followed by thermal cycling and humidity freeze (sequence 1); thermal cycling (500 cycles; sequence 2); damp heat (2000 hours; sequence 3). Overall, the average degradation of both modules in all the three sequences is found to be the lowest for the solder wire technology among the four investigated technologies assuming the influence of encapsulant and backsheet is identical in all the constructions.
Ulrich Bundles on Intersections of Two 4-Dimensional Quadrics

In this paper, we investigate the moduli space of Ulrich bundles on a smooth complete intersection of two $4$-dimensional quadrics in $\mathbb P^5$. The main ingredient is the semiorthogonal decomposition by Bondal–Orlov, combined with the categorical methods pioneered by Kuznetsov and Lahoz–Macrì–Stellari. Using these methods, we prove that any smooth intersection of two 4-dimensional quadrics in $\mathbb P^5$ carries an Ulrich bundle of rank $r$ for every $r \ge 2$. Moreover, we provide a description of the moduli space of stable Ulrich bundles.
Reliability and Validity of the Motor Activity Log (MAL-30) Scale for Post-Stroke Patients in a Spanish Sample

Background: The validation of assessment instruments is of great importance when they are applied in clinical and healthcare settings, since their safe and reliable use is essential for the application of appropriate and high-quality treatments. The motor activity log (MAL-30) is an instrument widely used by professionals in the clinic, which has been validated in different countries, languages and populations. The aim of this study was to determine the reliability and validity of the MAL-30 scale for post-stroke patients in a Spanish sample. Methods: For this purpose, internal consistency tests were carried out using Cronbach’s alpha, item–item and item–total correlations, and a half-and-half test for reliability. For the validation, criterion validity tests were performed using the Fugl-Meyer assessment scale as the gold standard, and the convergent validity tests were carried out by correlation with the action research arm test (ARAT), box and block test (BBT), functional independence measure (FIM)–functional assessment measure (FAM), Lawton and Brody index and stroke quality of life scale (ECVI-38). Results: The results showed good internal consistency, as well as a good criterion and convergent validity. Conclusions: The MAL-30 instrument can be considered a valid and reliable tool for assessing the quantity and quality of the use of the affected upper limb in the performance of the activities of daily living and the instrumental activities of daily living after stroke in a Spanish sample.
A proper motion study of the globular cluster M55

We have derived the absolute proper motion (PM) of the globular cluster M55 using a large set of CCD images collected with the du Pont telescope between 1997 and 2008. We find (μα cos δ, μδ) = (—3.31 ± 0.10, —9.14 ± 0.15) mas yr ―1 relative to background galaxies. Membership status was determined for 16 945 stars with 14 < V < 21 from the central part of the cluster. The PM catalogue includes 52 variables, of which 43 are probable members of M55. This sample not only is dominated by pulsating blue straggler stars, but also includes five eclipsing binaries, three of which are main-sequence objects. The survey also identified several candidate blue, yellow and red straggler stars belonging to the cluster. We detected 15 likely members of the Sgr dSph galaxy located behind M55. The average PM for these stars was measured to be (μα cos δ, μ δ ) = (―2.23 ± 0.14, ―1.83 ± 0.24) mas yr ―1 .
Combinatorial principles equivalent to weak induction

We consider two combinatorial principles, ${\sf{ERT}}$ and ${\sf{ECT}}$. Both are easily proved in ${\sf{RCA}}_0$ plus ${\Sigma^0_2}$ induction. We give two proofs of ${\sf{ERT}}$ in ${\sf{RCA}}_0$, using different methods to eliminate the use of ${\Sigma^0_2}$ induction. Working in the weakened base system ${\sf{RCA}}_0^*$, we prove that ${\sf{ERT}}$ is equivalent to ${\Sigma^0_1}$ induction and ${\sf{ECT}}$ is equivalent to ${\Sigma^0_2}$ induction. We conclude with a Weihrauch analysis of the principles, showing ${\sf{ERT}} {\equiv_{\rm W}} {\sf{LPO}}^* {<_{\rm W}}{{\sf{TC}}_{\mathbb N}}^* {\equiv_{\rm W}} {\sf{ECT}}$.
Raman Spectroscopy and Spectral Signatures of AlScN/Al2O3

III-V solid solutions are sensitive to growth conditions due to their stochastic nature. The highly crystalline thin films require a profound understanding of the material properties and reliable means of their determination. In this work, we have investigated the Raman spectral fingerprint of Al1−xScxN thin films with Sc concentrations x = 0, 0.14, 0.17, 0.23, 0.32, and 0.41, grown on Al2O3(0001) substrates. The spectra show softening and broadening of the modes related to the dominant wurtzite phase with increasing Sc content, in agreement with the corresponding XRD results. We investigated the primary scattering mechanism responsible for the immense modes’ linewidths by comparing the average grain sizes to the phonon correlation length, indicating that alloying augments the point defect density. The low-frequency Raman bands were attributed to the confined spherical acoustic modes in the co-forming ScN nanoparticles. Temperature-dependent Raman measurements enabled the temperature coefficient of the E2(high) mode to be determined for all Sc concentrations for the precise temperature monitoring in AlScN-based devices.
A SPITZER-MIPS SEARCH FOR DUST IN COMPACT HIGH-VELOCITY H i CLOUDS

We employ three-band Spitzer-MIPS observations to search for cold dust emission in three neutral hydrogen compact high-velocity clouds (CHVCs) in the vicinity of the Milky Way. Far-infrared emission correlated with H i column density was previously reported in HVC Complex C, indicating that this object contains dust heated by the Galactic radiation field at its distance of ∼10 kpc. Assuming published Spitzer, IRAS, and Planck, IR-H i correlations for Complex C, our Spitzer observations are of sufficient depth to directly detect 160 μm dust emission in the CHVCs if it is present at the same level as in Complex C, but no emission is detected in any of the targets. For one of the targets (CHVC289) which has well-localized H i clumps, we therefore conclude that it is fundamentally different from Complex C, with either a lower dust-to-gas ratio or a greater distance from the Galactic disk (and consequently cooler dust temperature). Firm conclusions cannot be drawn for the other two Spitzer-observed CHVCs since their small-scale H i structures are not sufficiently well known; nonetheless, no extended dust emission is apparent despite their relatively high H i column densities. The lack of dust emission in CHVC289 suggests that at least some compact high-velocity clouds objects may exhibit very low dust-to-gas ratios and/or greater Galactocentric distances than large HVC complexes.