Miracle-dz/UniFAR-FTUs huggingface dataset:
Multiferroic CuCrO2 under high pressure: In situ X-ray diffraction and Raman spectroscopic studies

The compression behavior of delafossite compound CuCrO2 has been investigated by in situ x-ray diffraction (XRD) and Raman spectroscopic measurements up to 23.2 and 34 GPa, respectively. X-ray diffraction data show the stability of ambient rhombohedral structure up to ∼23 GPa. Material shows large anisotropy in axial compression with c-axis compressibility, κc = 1.26 × 10−3(1) GPa−1 and a-axis compressibility, κa = 8.90 × 10−3(6) GPa−1. Our XRD data show an irreversible broadening of diffraction peaks. Pressure volume data when fitted to 3rd order Birch-Murnaghan equation of state give the value of bulk modulus, B0 = 156.7(2.8) GPa with its pressure derivative, B0′ as 5.3(0.5). All the observed vibrational modes in Raman measurements show hardening with pressure. Appearance of a new mode at ∼24 GPa indicates the structural phase transition in the compound. Our XRD and Raman results indicate that CuCrO2 may be transforming to an ordered rocksalt type structure under compression.
VSX J074727.6+065050: a new WZ Sagittae star in Canis minor

We present photometry of the first reported superoutburst of the dwarf nova VSX J074727.6+065050 during 2008 January and February. At its brightest the star reached magnitude 11.4 and this was followed by a slow decline at 0.09 mag/d for 19 days, corresponding to the plateau phase. There was then a rapid decline at 1.66 mag/d to a temporary minimum at magnitude 16.6 where it stayed for 2 to 3 days after which there were six remarkable echo outbursts before the star gradually faded back towards quiescence at ~magnitude 19.5. The overall outburst amplitude was at least 8 magnitudes and it lasted more than 80 days. During the plateau phase we observed common superhumps with Psh = 0.06070(6) d, but the period increased to Psh = 0.06151(5) d coinciding with the end of the plateau phase and the onset of the rapid decline. This corresponds to a continuous period change with P^dot = +4.4(9) x 10-5. During the echo outbursts there was a superhump regime with Psh = 0.06088(49) d. Evidence is presented which is consistent with the star being a member of the WZ Sge family of dwarf novae.
The incorporation of straw into the subsoil increases C, N, and P enzyme activities and nutrient supply by enriching distinctive functional microorganisms

Incorporation of crop residues into agricultural soils is a common practice that can improve soil quality. However, the impact of different straw incorporation techniques on soil bacteria and their functions is still not well understood, especially across soil depths. Here, we investigated the impact of three maize straw management methods (straw removal, straw incorporation into topsoil, and deep‐injected straw incorporation into subsoil) on soil bacterial communities and how they were linked to extracellular enzymes and soil properties. Deep‐injected straw incorporation strongly promoted enzyme activities: C‐cycling enzymes increased by 111–532 nmol g−1 hr−1, N‐cycling enzymes by 229–708 nmol g−1 hr−1, and P‐cycling enzymes by 142–216 nmol g−1 hr−1 compared to straw removal and straw incorporation into topsoil. In addition, deep‐injected straw incorporation considerably increased soil organic carbon (SOC), dissolved organic carbon (DOC), and total nitrogen (TN) compared to the other straw management methods (249–253% for SOC, 303–370% for DOC, and 178–196% for TN). However, in topsoil, only minimal effects of straw management practices on bacterial communities, enzymes activities, and soil properties were found. Deep‐injected straw incorporation favoured copiotrophic bacteria which resulted in a reduction of 41% in Shannon index. Bacteria associated with carbon and nitrogen cycling were mainly Actinobacteria, which were positively correlated with TN, SOC, and DOC. Acidobacteria were the dominant species in P‐cycling module and were positively associated with SOC, DOC, and available phosphorus. Overall, injection of straw into subsoil alters bacterial communities and functioning, and increases soil nutrients and soil organic C in subsoil.
Tetraquarks composed of 4 heavy quarks

In the current work spectroscopy and possibility of observation at the LHC of tetraquarks composed of 4 heavy quarks is discussed. Tetraquarks concerned are T_{4c}=[cc][cc]$, T_{4b}=[bb][bb] and T_{2[bc]}=[bc][bc]. By solving nonrelativistic Schroedinger equation masses of these states are found with the hyperfine splitting accounted for. It is shown that masses of tensor tetraquarks T_{4c}(2++) and T_{2[bc]}(2++) are high enough to observe these states as peaks in the invariant mass distributions of heavy quarkonia pairs in pp -> T_{4c}+X -> 2J/\psi+X, pp -> T_{2[bc]}+X -> 2B_{c}+X and pp -> T_{2[bc]}+X -> J/\psi\Upsilon(1S)+X channels while T_{4b} is under the threshold of decay into a vector bottomonia pair.
EVOLUTION OF STAR FORMATION PROPERTIES OF HIGH-REDSHIFT CLUSTER GALAXIES SINCE z = 2

Using a stellar mass-limited sample of ∼46,600 galaxies ( M * > 10 9.1 M ⊙ ? > ) at 0.5 < z < 2 ? > , we show that the stellar mass, rather than the environment, is the main parameter controlling quenching of star formation in galaxies with M * > 10 10 M ⊙ ? > out to z = 2. On the other hand, the environmental quenching becomes efficient at z < 1 ? > regardless of galaxy mass, and it serves as a main mechanism for quenching star formation for lower mass galaxies. Our result is based on deep optical and near-infrared imaging data over 2800 arcmin2, enabling us to negate cosmic variance and identify 46 galaxy cluster candidates with M ∼ 10 14 M ⊙ ? > . From M * ∼ 10 9.5 ? > to 10 10.5 M ⊙ ? > , the fraction of quiescent galaxies increases by a factor of ∼10 over the entire redshift range, but the difference between cluster and field environment is negligible. Rapid evolution in the quiescent fraction is seen from z = 2 to z = 1.3 for massive galaxies, suggesting a build-up of massive quiescent galaxies at z > 1.3 ? > . For galaxies with M * < 10 10 M ⊙ ? > at z < 1.0 ? > , the quiescent fraction is found to be as much as a factor of 2 larger in clusters than in field, showing the importance of environmental quenching in low-mass galaxies at low redshift. Most high-mass galaxies are already quenched at z > 1 ? > , therefore environmental quenching does not play a significant role for them, although the efficiency of environmental quenching is nearly identical between high- and low-mass galaxies.
Differentiation via Logarithmic Expansions

In this note, we introduce a new finite difference approximation called the Black-Box Logarithmic Expansion Numerical Derivative (BLEND) algorithm, which is based on a formal logarithmic expansion of the differentiation operator. BLEND capitalizes on parallelization and provides derivative approximations of arbitrary precision, i.e., our analysis can be used to determine the number of terms in the series expansion to guarantee a specified number of decimal places of accuracy. Furthermore, in the vector setting, the complexity of the resulting directional derivative is independent of the dimension of the parameter.
Quantum state of a frequency comb

Uncertainties in the frequency parameters of a frequency comb laser, causes it to represent a mixed quantum state. The formulation of such a quantum state is compounded by the fact that it contains both particle-number degrees of freedom and temporal degrees of freedom. Here we develop a formalism in terms of which such a mixed quantum state can be expressed. For this purpose we also need to compute the expression for the power spectral density of the frequency comb laser. We do so by taking the uncertainties in the frequency parameters into account.
Logarithmic behavior of the degradation dynamics of metal–oxide–semiconductor devices

In this paper the authors describe a simple theoretical statistical model of the process of relaxation in metal–oxide–semiconductor devices that governs the degradation. Basically, starting from an initial state where a given number of traps are occupied, the dynamics of the relaxation process is measured, and the density of occupied traps and its fluctuations (second moment) as a function of time are calculated. Our theoretical results show an emergent logarithmic behavior for the density of occupied traps: , i.e., the degradation is logarithmic and its amplitude depends only on the temperature and the Fermi level (applied bias voltage) of the device.
TIME AND FREQUENCY DOMAIN METHODS FOR BASIS SELECTION IN RANDOM LINEAR DYNAMICAL SYSTEMS

Polynomial chaos methods have been extensively used to analyze systems in uncertainty quantification. Furthermore, several approaches exist to determine a low-dimensional approximation (or sparse approximation) for some quantity of interest in a model, where just a few orthogonal basis polynomials are required. We consider linear dynamical systems consisting of ordinary differential equations with random variables. The aim of this paper is to explore methods for producing low-dimensional approximations of the quantity of interest further. We investigate two numerical techniques to compute a low-dimensional representation, which both fit the approximation to a set of samples in the time domain. On the one hand, a frequency domain analysis of a stochastic Galerkin system yields the selection of the basis polynomials. It follows a linear least squares problem. On the other hand, a sparse minimization yields the choice of the basis polynomials by information from the time domain only. An orthogonal matching pursuit produces an approximate solution of the minimization problem. We compare the two approaches using a test example from a mechanical application.
The Effect of Therapeutic Hypothermia on Plasma Levels of Thyroid Hormones During Hemorrhagic Shock in Adult Male Wistar Rats

Background and Aim: Hemorrhagic shock (HS) is one of the most important causes of death. In this study, we investigated the benefits of therapeutic hypothermia (32°C) during HS on blood pressure (BP) and the role of thyroid hormones during HS. Materials and Methods: Twenty-four male Wistar rats were divided into two normothermic hemorrhagic (NH) and hypothermic hemorrhagic (HH) groups (32°C during shock); the animals were then anesthetized, a microcatheter was inserted into the femoral artery, and one into the femoral vein. The arterial samples were centrifuged, and plasma was isolated to measure thyroid hormones later. The microcatheter was fixed to a physiograph to record BP. Animals were exposed to HS for 90 minutes by withdrawing blood from the femoral vein and BP was assessed during HS. Results: The BP of HH animals was significantly higher in most times of HS and at 40 minutes (56.8±4.2 mmHg) in comparison to NH rats (45.4±3.8 mmHg) (P<0.05). In addition, the amount of BP in HH animals at the end of the shock period at 90 minutes (63.8±5.5 mmHg) was significantly (P<0.001) higher in comparison with the NH groups (39±3.2 mmHg). Levels of thyroid hormones T4 and T3 at the end of shock were lower in the HH group compared to the NH group (P<0.001). Conclusion: Therapeutic hypothermia indirectly reduces the level of thyroid hormones and directly reduces the metabolism of non-vital tissues, preserves blood in the central arteries, and increases BP.
Geometry of reduced density matrices for symmetry-protected topological phases

Tsinghua Univ, Dept Phys, State Key Lab Low Dimens Quantum Phys, Beijing 100084, Peoples R China. Perimeter Inst Theoret Phys, Waterloo, ON, Canada. Univ Waterloo, Inst Quantum Comp, Waterloo, ON N2L 3G1, Canada. Chinese Acad Sci, Inst Software, State Key Lab Comp Sci, Beijing, Peoples R China. Tsinghua Univ, Inst Adv Study, Beijing 100084, Peoples R China. Univ Waterloo, Dept Stat & Actuarial Sci, Waterloo, ON N2L 3G1, Canada. Univ Guelph, Dept Math & Stat, Guelph, ON N1G 2W1, Canada.
Littlewood-Paley-Stein functions for Schrödinger operators

We study the boundedness on L(R) of the vertical LittlewoodPaley-Stein functions for Schrödinger operators −∆ + V with nonnegative potentials V . These functions are proved to be bounded on L for all p ∈ (1, 2). The situation for p > 2 is different. We prove for a class of potentials that the boundedness on L, for some p > d, holds if and only if V = 0. Mathematics Subject Classification: 42B25, 47F05
Viscous Driving of Global Oscillations in Accretion Discs Around Black Holes

We examine the role played by viscosity in the excitation of global oscillation modes (both axisymmetric and non-axisymmetric) in accretion discs around black holes using two-dimensional hydrodynamic simulations. The turbulent viscosity is modeled by the $\alpha$-ansatz, with different equations of state. We consider both discs with transonic radial inflows across the innermost stable circular orbit, and stationary discs truncated by a reflecting wall at their inner edge, representing a magnetosphere. In transonic discs, viscosity can excite several types of global oscillation modes. These modes are either axisymmetric with frequencies close to multiples of the maximum radial epicyclic frequency $\kappa_\mathrm{max}$, non-axisymmetric with frequencies close to multiples of of the innermost stable orbit frequency $\Omega_\mathrm{ISCO}$, or hybrid modes whose frequencies are linear combinations of these two frequencies. Small values of the viscosity parameter $\alpha$ primarily produce non-axisymmetric modes, while axisymmetric modes become dominant for large $\alpha$. The excitation of these modes may be related to an instability of the sonic point, at which the radial infall speed is equal to the sound speed of the gas. In discs with a reflective inner boundary, we explore the effect of viscosity on trapped $p$-modes which are intrinsically overstable due to the corotation resonance effect. The effect of viscosity is either to reduce the growth rates of these modes, or to completely suppress them and excite a new class of higher frequency modes. The latter requires that the dynamic viscosity scales positively with the disc surface density, indicating that it is a result of the classic viscous overstability effect.
The potential influence of far-infrared emission lines on the selection of high-redshift galaxies

We investigate whether strong molecular and atomic emission lines at far-infrared wavelengths can influence the identification and derived properties of galaxies selected from broad-band, far-infrared or submillimetre observations. Several of these lines, for example, [C ii] 158 μm, have been found to be very bright in some galaxies, with fluxes of ≳0.1–1 per cent of the total far-infrared luminosity, and may be even brighter in certain populations at high redshifts. At redshifts where these lines fall in instrument passbands, they can significantly increase the broad-band flux measurements. We estimate that the contributions from line emission could boost the apparent broad-band flux by ≳20–40 per cent in the Herschel and SCUBA-2 bands. Combined with the steep source counts in the submillimetre and far-infrared bands, line contamination has potentially significant consequences for the properties of sources detected in flux-limited continuum surveys, biasing the derived redshift distributions and bolometric luminosities. Indeed, it is possible that some z > 4 sources found in 850-μm surveys are being identified in part due to the line contamination from strong [C ii] emission. These biases may be even stronger for less-luminous and lower metallicity populations at high redshifts, which are observable with the ALMA and which may have even stronger line-to-continuum ratios.
Is the log-law a first principle result from Lie-group invariance analysis?

The invariance method of Lie-groups in the theory of turbulence carries the high expectation of being a first principle method for generating statistical scaling laws. The purpose of this comment is to show that this expectation has not been met so far. In particular for wall-bounded turbulent flows, the prospects for success are not promising in view of the facts we will present herein. Although the invariance method of Lie-groups is able to generate statistical scaling laws for wall-bounded turbulent flows, like the log-law for example, these invariant results yet not only fail to fulfil the basic requirements for a first principle result, but also are strongly misleading. The reason is that not the functional structure of the log-law itself is misleading, but that its invariant Lie-group based derivation yielding this function is what is misleading. By revisiting the study of Oberlack (2001) we will demonstrate that all Lie-group generated scaling laws derived therein do not convince as first principle solutions. Instead, a rigorous derivation reveals complete arbitrariness rather than uniqueness in the construction of invariant turbulent scaling laws. Important to note here is that the key results obtained in Oberlack (2001) are based on several technical errors, which all will be revealed, discussed and corrected. The reason and motivation why we put our focus solely on Oberlack (2001) is that it still marks the core study and central reference point when applying the method of Lie-groups to turbulence theory. Hence it is necessary to shed the correct light onto that study. Nevertheless, even if the method of Lie-groups in its full extent is applied and interpreted correctly, strong natural limits of this method within the theory of turbulence exist, which, as will be finally discussed, constitute insurmountable obstacles in the progress of achieving a significant breakthrough.
Holographic Chiral Electric Separation Effect

We investigate the chiral electric separation effect, where an axial current is induced by an electric field in the presence of both vector and axial chemical potentials, in a strongly coupled plasma via the Sakai-Sugimoto model with a U ( 1 ) R × U ( 1 ) L symmetry. By introducing different chemical potentials in U ( 1 ) R and U ( 1 ) L sectors, we compute the axial direct current (DC) conductivity stemming from the chiral current and the normal DC conductivity. We find that the axial conductivity is approximately proportional to the product of the axial and vector chemical potentials for arbitrary magnitudes of the chemical potentials. We also evaluate the axial alternating current (AC) conductivity induced by a frequency-dependent electric field, where the oscillatory behavior with respect to the frequency is observed.
ANALYSIS OF DETACHED ECLIPSING BINARIES NEAR THE TURNOFF OF THE OPEN CLUSTER NGC 7142

We analyze extensive BVRCIC photometry and radial velocity measurements for three double-lined deeply eclipsing binary stars in the field of the old open cluster NGC 7142. The short period (P = 1.9096825 days) detached binary V375 Cep is a high probability cluster member, and has a total eclipse of the secondary star. The characteristics of the primary star (M = 1.288 ± 0.017 M☉) at the cluster turnoff indicate an age of 3.6 Gyr (with a random uncertainty of 0.25 Gyr), consistent with earlier analysis of the color–magnitude diagram. The secondary star (M = 0.871 ± 0.008 M☉) is not expected to have evolved significantly, but its radius is more than 10% larger than predicted by models. Because this binary system has a known age, it is useful for testing the idea that radius inflation can occur in short period binaries for stars with significant convective envelopes due to the inhibition of energy transport by magnetic fields. The brighter star in the binary also produces a precision estimate of the distance modulus, independent of reddening estimates: (m − M)V = 12.86 ± 0.07. The other two eclipsing binary systems are not cluster members, although one of the systems (V2) could only be conclusively ruled out as a present or former member once the stellar characteristics were determined. That binary is within 0. °5 of edge-on, is in a fairly long-period eccentric binary, and contains two almost indistinguishable stars. The other binary (V1) has a small but nonzero eccentricity (e = 0.038) in spite of having an orbital period under 5 days.
Nowadays cosmology with the Weyl-Dirac approach

Some problems of cosmology: the big bang singularity, the origin of conventional matter, of dark matter and of dark energy may be successfully described and treated in the framework of the Weyl-Dirac theory. This theory, being a minimal expansion of Einstein's GRT, contains in addition to the metric tensor\g, the Weyl connection vector \w and the Dirac gauge function\beta. From these geometrically based quantities one obtains the behavior of our universe. The Weyl connection vector \w existing in microcells creates dark matter particles, weylons. In the very early universe \beta creates matter, whereas in the present dust period \beta forms dark energy, the latter causing cosmic acceleration. Around a massive body the - dark energy form a ball-like concentration having negative mass and negative pressure. These \beta-balls cause an additional acceleration of the expanding universe. The Weyl-Dirac theory is a classical geometrically based framework appropriate for describing and searching cosmology.
SUB-PHOTOSPHERIC, RADIATION-MEDIATED SHOCKS IN GAMMA-RAY BURSTS: MULTIPLE SHOCK EMISSION AND THE BAND SPECTRUM

We compute the time-integrated, thermal emission produced by a series of radiation-mediated shocks that emerge from the photosphere of a gamma-ray burst outflow. We show that for a sufficiently broad distribution of shock strengths, the overall shape of the time-integrated spectral energy distribution below the peak is a power law, νEν∝να, with a slope of 1 < α < 2. A substructure in the spectral energy distribution (SED) can also be produced in this model for certain choices of the shock train distribution. In particular, we demonstrate that our model can reproduce the double-peak SED observed in some bursts, in events where a strong shock is followed by a sequence of sufficiently weaker ones.
Simultaneous optical and near-IR photometry of 4U1957+115 - a missing secondary star

We report the results of quasi-simultaneous optical and NIR photometry of the lowmass X-ray binary, 4U 1957+115. Our observations cover B, V, R, I, J, H and K-bands and additional time-series NIR photometry. We measure a spectral energy distribution, which can be modelled using a standard multi-temperature accretion disc, where the disc temperature and radius follow a power-law relation. Standard accretion disc theory predicts the power law exponent to be -3/4, and this yields, perhaps surprisingly, acceptable fits to our SED. Given that the source is a persistent X-ray source, it is however likely that the accretion disc temperature distribution is produced by X-ray heating, regardless of its radial dependence. Furthermore, we find no evidence for any emission from the secondary star at any wavelength. However, adding a secondary component to our model allows us to derive a 99% lower limit of 14 or 15 kpc based on Monte Carlo simulations and using either an evolved K2 or G2V secondary star respectively. In >60% of cases the distance is >80kpc. Such large distances favor models with a massive (>15 M⊙) black hole primary. Our quasi-simultaneous J and V-band time-series photometry, together with the SED, reveals that the optical/NIR emission must originate in the same region i.e. the accretion disc. The likely extreme mass ratio supports suggestions that the accretion disc must be precessing which, depending on the length of the precession period, could play a major part in explaining the variety of optical light curve shapes obtained over the last two decades.