Miracle-dz/UniFAR-FTUs huggingface dataset:
Tensile Stress-Strain Behavior of Piezoelectric Ceramics

Fracture strength and stress-strain behavior under tensile stress in piezoelectric ceramics have been investigated with special emphasis on the effects of poling conditions. The materials used in this work are the commercial piezoelectric ceramics, PbZrO3-PbTiO3 (PZT) and BaTiO3. First, an attempt was made to evaluate the tensile strength properties of samples having a specially designed specimen geometry. In the actual tensile test, fracture did not occur at the gripping portion at all, indicating usefulness of the present tensile test method. Not only fracture strength, but also elastic properties, tensile modulus and Poisson's ratio, were evaluated. Second, an investigation was performed on the stress-strain behavior under tension in this material. As a result, stress-strain response under tension was confirmed to be nonlinear. The nonlinearity in the stress-strain relationship under compression loading has already been reported by some investigators. However, very little work has been done on the tensile stress-strain relationship studied in this paper. Third, acoustic emission monitoring was performed simultaneously during tensile tests, and thus the tensile failure process in piezoelectric ceramics was discussed.
Heat Conduction Analysis in an Anisotropic Thin Film Irradiated by an Ultrafast Pulse Laser Heating

The microscale heat conduction in an anisotropic thin-film subjected to an ultrafast laser heating is investigated. The coordinate transformation (CT) method has been employed to transform microscale heat conduction equations in an anisotropic thin-film to those of isotropic ones in the mapped domain. A comparison among three different models was made to investigate the effect of anisotropic thermal properties on the microscale heat conduction. Numerical results show that the CT method can be a good candidate to explore the microscale heat conduction mechanism in an anisotropic thin-film imposed by ultrafast pulse laser heating. The anisotropic heat conduction mechanism becomes more important when the thin film excited by multiple consecutive pulses with high power femtosecond laser. The multiple consecutive pulses with large separation time will spend much time to reach the thermal equilibrium state.
Recurrent star-spot activity and differential rotation in KIC 11560447

We present a detailed analysis of surface inhomogeneities on the K1-type sub-giant component of the rapidly rotating eclipsing binary KIC 11560447, using high-precision Kepler light curves spanning nearly four years, corresponding to about 2800 orbital revolutions. We precisely determine the system parameters using high-resolution spectra from the 2.1-m Otto Struve Telescope at the McDonald Observatory. We apply the maximum entropy method to reconstruct the relative longitudinal spot occupancy. Our numerical tests show that the procedure can recover large-scale random distributions of individually unresolved spots, and can track the phase migration of up to three major spot clusters. By determining the drift rates of various spotted regions in orbital longitude, we suggest a way to constrain surface differential rotation and show that the results are consistent with periodograms. The K1IV star exhibits two mildly preferred longitudes of emergence, indications of solar-like differential rotation, and a 0.5 to 1.3-year recurrence period in starspot emergence, accompanied by a secular increase in the axisymmetric component of spot occupancy.
Charge redistribution and the magnetoelastic transition across the first-order magnetic transition in (Mn,Fe)
2
(P,Si,B)

We used temperature dependent high-resolution x-ray powder diffraction and magnetization measurements to investigate structural, magnetic and electronic degrees of freedom across the ferromagnetic magnetoelastic phase transition in $\mathrm{M}{\mathrm{n}}_{1}\mathrm{F}{\mathrm{e}}_{1}{\mathrm{P}}_{0.6\ensuremath{-}\mathrm{w}}\mathrm{S}{\mathrm{i}}_{0.4}{\mathrm{B}}_{\mathrm{w}}$ ($w=0$, 0.02, 0.04, 0.06, 0.08). The magnetic transition was gradually tuned from a strong first-order ($w=0$) towards a second-order magnetic transition by substituting P by B. Increasing the B content leads to a systematic increase in the magnetic transition temperature and a decrease in thermal hysteresis, which is below 1 K for $w=0.08$. Furthermore, the largest changes in lattice parameter across the magnetic transition occur for $w=0$, which systematically becomes smaller approaching the samples with $w=0.08$. Electron density plots show a strong directional preference of the electronic distribution around Fe, which indicates the forming of bonds between Fe atoms and Fe and P/Si in the paramagnetic phase. On the other hand, Mn shows no preferred directions. Due to the low B concentrations ($wl0.08$), distortions of the lattice are limited. However, even small amounts of B strongly disturb the overall distribution of the electron density across the unit cell. Samples containing B show a strongly reduced change in the electron density compared to the parent compound without B. The magnetoelastic coupling shows a continuous weakening with the B content.
The E-Derivative and Completeness on Circuit Error-Detection System of Differential Equations

Through discuss the relations of e-derivative, derivative and logical functions, we propose e-derivative differential equations detective method of circuit error. We gives the theorems and proved theoretically that circuit error-detection system, which combines with e-derivative differential equations detective method and derivative differential equations detective method is having completeness, this system is able to detect all the circuit error. At the same time, we explain that the corresponding principles of the circuit error-detection system, and reveals the relationship between the circuit error and the function data (value). Finally, we give detection examples for all possible detected cases. For the present error-detection system only with derivative differential equations detective method, the circuit error-detection system which we proposed make up the deficiency and defect of the original system, which can not be detected for many circuit error and is do not know the reasons. We construct a complete circuit error-detection system.
Non-Abelian topological phases in an extended Hubbard model

We describe four closely related Hubbard-like models (models A, B, C and D) of particles that can hop on a 2D Kagome lattice interacting via Coulomb repulsion. The particles can be either bosons (models A and B) or (spinless) fermions (models C and D). Models A and C also include a ring exchange term. In all four cases we solve equations in the model parameters to arrive at an exactly soluble point whose ground state manifold is the extensively degenerate ``d-isotopy space'' $\bar{V}_d$, 0<d<2. Near the ``special'' values, $d = 2 \cos \pi/k+2$, $\bar{V}_d$ should collapse to a stable topological phase with anyonic excitations closely related to SU(2) Chern-Simons theory at level k. We mention simplified models $A^-$ and $C^-$ which may also lead to these topological phases.
The gravitational lens system 2016+112 revisited

In the light of recently reported observations of the triple radio source 2016+112 by Schneider et al. (1985, 1986), gravitational lens models of this system are constructed based on two lens galaxies and a cluster. Various observations of this multiply imaged quasar system, including some of the features accompanying object C, are reasonably well reproduced. The admissible lens models involve a five-image configuration with two merging images rather than just three images. In this respect this lens system is analogous to the triple quasar 1115+080. In the models the emission line regions accompanying images A and B arise from two distinct sources. A measurement of time delays, a relation between conceivable VLBI structures associated with images, and further radio observations of the object C as possible tests of the lens models are suggested. 14 references.
A 3π Search for Planet Nine at 3.4 μm with WISE and NEOWISE

The recent “Planet Nine” hypothesis has led to many observational and archival searches for this giant planet proposed to orbit the Sun at hundreds of astronomical units. While trans-Neptunian object searches are typically conducted in the optical, models suggest Planet Nine could be self-luminous and potentially bright enough at ∼3–5 μm to be detected by the Wide-field Infrared Survey Explorer (WISE). We have previously demonstrated a Planet Nine search methodology based on time-resolved WISE coadds, allowing us to detect moving objects much fainter than would be possible using single-frame extractions. In the present work, we extend our 3.4 μm (W1) search to cover more than three-quarters of the sky and incorporate four years of WISE observations spanning a seven-year time period. This represents the deepest and widest-area WISE search for Planet Nine to date. We characterize the spatial variation of our survey’s sensitivity and rule out the presence of Planet Nine in the parameter space searched at W1 < 16.7 in high Galactic latitude regions (90% completeness).
The Simplest Form of the Lorentz Transformations

We report the simplest possible form to compute rotations around arbitrary axis and boosts in arbitrary directions for 4-vectors (space-time points, energy-momentum) and bi-vectors (electric and magnetic field vectors) by symplectic similarity transformations. The Lorentz transformations are based exclusively on real $4\times 4$-matrices and require neither complex numbers nor special implementations of abstract entities like quaternions or Clifford numbers. No raising or lowering of indices is necessary. It is explained how the Lorentz transformations can be derived from the most simple second order Hamiltonian of general significance. Since this approach exclusively uses the real Clifford algebra $Cl(3,1)$, all calculations are based on real $4\times 4$ matrix algebra.
The possible orbital period of the nova V1493 Aquilae

Aims. Period analysis of CCD photometry of V1493 Aql (Nova Aql 1999 No. 1) performed during 12 nights through I and R filters a few weeks after maximum is presented. Methods. The PDM method for period analysis (Stellingwerf 1978, ApJ, 224, 953) is used. Results. The photometric data is modulated with a period of $0.156 \pm 0.001$ d. Following the sinusoidal shape of the phased light curve, we interpret this periodicity as possibly orbital in nature and that is consistent with a cataclysmic variable above the period gap.
Phase-space distribution of unbound dark matter near the Sun

We resolve discrepancies in previous analyses of the flow of collisionless dark matter particles in the Sun's gravitational field. We determine the phase-space distribution of the flow both numerically, tracing particle trajectories back in time, and analytically, providing a simple correct relation between the velocity of particles at infinity and at the Earth. We use our results to produce sky maps of the distribution of arrival directions of dark matter particles on Earth at various times of the year. We assume various Maxwellian velocity distributions at infinity describing the standard dark halo and streams of dark matter. We illustrate the formation of a ring, analogous to the Einstein ring, when the Earth is directly downstream of the Sun.
fLRR: fast low-rank representation using Frobenius-norm

Low-rank representation (LRR) intends to find the representation with lowest rank of a given data set, which can be formulated as a rank-minimisation problem. Since the rank operator is non-convex and discontinuous, most of the recent works use the nuclear norm as a convex relaxation. It is theoretically shown that, under some conditions, the Frobenius-norm-based optimisation problem has a unique solution that is also a solution of the original LRR optimisation problem. In other words, it is feasible to apply the Frobenius norm as a surrogate of the non-convex matrix rank function. This replacement will largely reduce the time costs for obtaining the lowest-rank solution. Experimental results show that the method (i.e. fast LRR (fLRR)) performs well in terms of accuracy and computation speed in image clustering and motion segmentation compared with nuclear-norm-based LRR algorithm.
Motion correction in cardiac perfusion data by using robust matrix decomposition

Motion free reconstruction of compressively sampled cardiac perfusion MR images is a challenging problem. It is due to the aliasing artifacts and the rapid contrast changes in the reconstructed perfusion images. In addition to the reconstruction limitations, many registration algorithms under perform in the presence of the rapid intensity changes. In this paper, we propose a novel motion correction method that reconstructs the motion free image series from the undersampled cardiac perfusion MR data. The motion correction method uses the novel robust principal component analysis based reconstruction along with the periodic decomposition to separate the respiratory motion component that can be registered, from the contrast intensity variations. It is tested on simulated data and the clinically acquired data. The performance of the method is qualitatively assessed and compared with the existing motion correction methods. The proposed method is validated by comparing manually acquired time-intensity curves of the myocardial sectors to automatically generated curves before and after registration.
Light Curves of Gamma-Ray Burst Optical Flashes

The standard model of gamma-ray burst (GRB) afterglows assumes that relativistically expanding material is decelerating as a result of interaction with the surrounding medium. The afterglows are well described by the synchrotron radiation from a forward shock, while the strong optical flash associated with GRB 990123 can be attributed to the emission from a reverse shock. We give a detailed study on the reverse shock emission. The full light curves are calculated for long and short GRB cases. We discuss the lack of the prompt optical detections by ROTSE for GRB 981121 and GRB 981223.
What mechanisms dominate the activity of Geminid Parent (3200) Phaethon?

A long-term sublimation model to explain how Phaethon could provide the Geminid stream is proposed. We find that it would take $\sim6$ Myr or more for Phaethon to lose all of its internal ice (if ever there was) in its present orbit. Thus, if the asteroid moved from the region of a 5:2 or 8:3 mean motion resonance with Jupiter to its present orbit less than $1$ Myr ago, it may have retained much of its primordial ice. The dust mantle on the sublimating body should have a thickness of at least $15$ m but the mantle could have been less than $1$ m thick $1000$ years ago. We find that the total gas production rate could have been as large as $10^{27}\rm~s^{-1}$ then, and the gas flow could have been capable of lifting dust particles of up to a few centimeters in size. Therefore, gas production during the past millennium could have been sufficient to blow away enough dust particles to explain the entire Geminid stream. For present-day Phaethon, the gas production is comparatively weak. But strong transient gas release with a rate of $\sim4.5\times10^{19}\rm~m^{-2}s^{-1}$ is expected for its south polar region when Phaethon moves from $0^\circ$ to $2^\circ$ mean anomaly near perihelion. Consequently, dust particles with radii of $ 600$ K near perihelion can generate sufficiently large thermal stress to cause fracture of rocks or boulders and provide an efficient mechanism to produce dust particles on the surface. The time scale for this process should be several times longer than the seasonal thermal cycle, thereby dominating the cycle of appearance of the dust tail.
Effects of Cloud Horizontal Inhomogeneity on the Optical Thickness Retrieved from Moderate-Resolution Satellite Data

Abstract Cloud remote sensing techniques are conventionally based on the independent pixel approximation (IPA). Here, three-dimensional (3D) radiative effects on IPA-based retrieved optical thickness from a visible-wavelength moderate-resolution (about 1 km) sensor are investigated. A Monte Carlo 3D radiative transfer model and a lognormal spectral cloud model are used to simulate monochromatic radiance reflected from overcast boundary layer cloud. A characterization of statistical properties of the optical thickness by the mean (M) and variance (S2) of the logarithm of the optical thickness is proposed, where S represents a degree of cloud inhomogeneity. Biases in retrieved values of the two parameters with the IPA are defined as ΔM and ΔS2 and attributed to neglect of net horizontal radiative transport in the IPA. Sensitivities of ΔM and ΔS2 are tested with respect to geometrical roughness, M, S, mean geometrical thickness, spectral exponent of optical thickness fluctuation, ground surface reflectance, .
Quantifying magic for multi-qubit operations

The development of a framework for quantifying ‘non-stabilizerness’ of quantum operations is motivated by the magic state model of fault-tolerant quantum computation and by the need to estimate classical simulation cost for noisy intermediate-scale quantum (NISQ) devices. The robustness of magic was recently proposed as a well-behaved magic monotone for multi-qubit states and quantifies the simulation overhead of circuits composed of Clifford + T gates, or circuits using other gates from the Clifford hierarchy. Here we present a general theory of the ‘non-stabilizerness’ of quantum operations rather than states, which are useful for classical simulation of more general circuits. We introduce two magic monotones, called channel robustness and magic capacity, which are well-defined for general n-qubit channels and treat all stabilizer-preserving CPTP maps as free operations. We present two complementary Monte Carlo-type classical simulation algorithms with sample complexity given by these quantities and provide examples of channels where the complexity of our algorithms is exponentially better than previously known simulators. We present additional techniques that ease the difficulty of calculating our monotones for special classes of channels.
Future constraints on the gravitational slip with the mass profiles of galaxy clusters

The gravitational slip parameter is an important discriminator between large classes of gravity theories at cosmological and astrophysical scales. In this work we use a combination of simulated information of galaxy cluster mass profiles, inferred by Strong+Weak lensing analyses and by the study of the dynamics of the cluster member galaxies, to reconstruct the gravitational slip parameter $\eta$ and predict the accuracy with which it can be constrained with current and future galaxy cluster surveys. Performing a full-likelihood statistical analysis, we show that galaxy cluster observations can constrain $\eta$ down to the percent level already with a few tens of clusters. We discuss the significance of possible systematics, and show that the cluster masses and numbers of galaxy members used to reconstruct the dynamics mass profile have a mild effect on the predicted constraints.
Age Determination in Upper Scorpius with Eclipsing Binaries

The Upper Scorpius OB association is the nearest region of recent massive star formation and thus an important benchmark for investigations concerning stellar evolution and planet formation timescales. We present nine eclipsing binaries (EBs) in Upper Scorpius, three of which are newly reported here and all of which were discovered from K2 photometry. Joint fitting of the eclipse photometry and radial velocities from newly acquired Keck I/HIRES spectra yields precise masses and radii for those systems that are spectroscopically double-lined. The binary orbital periods in our sample range from 0.6 to 100 days, with total masses ranging from 0.2 to 8 M⊙. At least 33% of the EBs reside in hierarchical multiples, including two triples and one quadruple. We use these EBs to develop an empirical mass–radius relation for pre-main-sequence stars and evaluate the predictions of widely used stellar evolutionary models. We report evidence for an age of 5–7 Myr, which is self-consistent in the mass range of 0.3–5 M⊙ and based on the fundamentally determined masses and radii of EBs. Evolutionary models including the effects of magnetic fields imply an age of 9–10 Myr. Our results are consistent with previous studies that indicate that many models systematically underestimate the masses of low-mass stars by 20%–60% based on Hertzsprung–Russell diagram analyses. We also consider the dynamical states of several binaries and compare with expectations from tidal dissipation theories. Finally, we identify RIK 72 b as a long-period transiting brown dwarf (M = 59.2 ± 6.8 MJup, R = 3.10 ± 0.31 RJup, P ≈ 97.8 days) and an ideal benchmark for brown dwarf cooling models at 5–10 Myr.
Circumnuclear Star Formation and AGN Activity: Clues from Surface Brightness Radial Profile of PAHs and [ S IV ]

We studied the circumnuclear mid-IR emission in a sample of 19 local active galactic nuclei (AGNs) with high spatial resolution spectra using T-ReCS (Gemini) and CanariCam (GTC), together with Spitzer/IRS observations. We measured the flux and the equivalent width for the 11.3 μm PAH feature and the [S iv] line emission as a function of galactocentric distance. This allowed us to study the star formation (SF) at subkiloparsec scales from the nucleus for a large sample of nearby AGNs. The [S iv] line emission could be tracing the AGN radiation field within a few thousand times the sublimation radius (Rsub), but it often peaks at distances greater than 1000 Rsub. One possibility is that the SF is contributing to the [S iv] total flux. We found an 11.3 μm PAH emission deficit within the inner few tens of parsecs from the AGN. This deficit might be due to the destruction of the molecules responsible for this feature or the lack of SF at these distances. We found a sensible agreement in the expected shift of the relation of the AGN bolometric luminosity and the SF rate. This indicates that numerical models attributing the link between AGN activity and host galaxy growth to mergers are in agreement with our data, for most inner galaxy parts.
Stability estimate and the Aharonov-Bohm effect for the Klein-Gordon equation with time-dependent vector potentials

We consider the relativistic Schr\"odinger (Gordon-Klein) equation with a time dependent vector and a scalar potential on a bounded cylindrical domain. Using a standard Geometric Optics Ansatz, we establish a logarithmic stability estimate for the recovery of the vector potentials. We also study the recovery of the potentials in the presence of obstacles. It is shown that under some geometric restrictions, the recovery of the potentials is possible up to a gauge transform.
Evidence for Free Precession in the Pulsar B1642–03

We present an analysis of the timing data of the pulsar B1642-03, collected over a span of 30 years between 1969 and 1999. During this interval, the timing residuals exhibit cyclical changes with amplitude varying from 15 to 80 ms and spacing of maxima varying from 3 to 7 yr. Interpretation of these observed cyclical changes in terms of free precession suggests a wobble angle of about 0. °8.