Miracle-dz/UniFAR-FTUs huggingface dataset:
An extremal problem for functions of positive real part with application to a radius of convexity problem

Re{ei[zff(z)/g(z) ]> 0 forz E A. The radius of convexity of K(a, X) is the greatest value of r, 0 0 for lzl 0, z E A) by means of some results of Ruscheweyh [6]. The latter problem turns out to be equivalent to the former one with g(z) _ z. We approach the problem of finding the radius of convexity of K(a, X) by first determining
Intercomparison of bulk cloud microphysics schemes in mesoscale simulations of springtime Arctic mixed-phase stratiform clouds

Abstract A persistent, weakly forced, horizontally extensive mixed-phase boundary layer cloud observed on 4–5 May 1998 during the Surface Heat Budget of the Arctic Ocean (SHEBA)/First International Satellite Cloud Climatology Project (ISCCP) Regional Experiment–Arctic Clouds Experiment (FIRE–ACE) is modeled using three different bulk microphysics parameterizations of varying complexity implemented into the polar version of the fifth-generation Pennsylvania State University–National Center for Atmospheric Research Mesoscale Model (MM5). The two simpler schemes predict mostly ice clouds and very little liquid water, while the complex scheme is able to reproduce the observed persistence and horizontal extent of the mixed-phase stratus deck. This mixed-phase cloud results in radiative warming of the surface, the development of a cloud-topped, surface-based mixed layer, and an enhanced precipitation rate. In contrast, the optically thin ice clouds predicted by the simpler schemes lead to radiative cooling of t.
Characteristics of mode-hopping noise and its suppression with the help of electric negative feedback in semiconductor lasers

Some detailed properties of mode-hopping noise in semiconductor injection lasers are reported, and the validity of electric negative feedback as a method of suppressing the noise is demonstrated. Mode-hopping noise was found to be an intrinsic property of the laser, independent of optical feedback (reinjection of the output light) reflected at the surface of an external device. The optical feedback works to shift the operating point of the laser from a stable condition having single-mode operation to an unstable condition revealing the modehopping phenomena. Characteristics of the mode-hopping noise support well the theoretical analysis in which the source of the noise is assumed to be fluctuations of the emission and the electron wave accompanied by spontaneous emission and in which the noise is amplified through mechanism of the mode competition phenomena. Mode-hopping noise was suppressed with the help of the electric negative feedback from the optical detector to the injection current source more effectively than by another reducing method of superposition of the high-frequency current. The suppressed noise level was lower than that at stable single-mode operation.
Theory of high field carrier transport and impact ionization in wurtzite GaN. Part I: A full band Monte Carlo model

High field electron and hole transport in wurtzite phase GaN is studied using an ensemble Monte Carlo method. The model includes the details of the full band structure derived from nonlocal empirical pseudopotential calculations. The nonpolar carrier-phonon interaction is treated within the framework of the rigid pseudoion approximation using ab initio techniques to determine the phonon dispersion relation. The calculated carrier-phonon scattering rates are consistent with the electronic structure and the phonon dispersion relation thus removing adjustable parameters such as deformation potential coefficients. The impact ionization transition rate is computed based on the calculated electronic structure and the corresponding wave-vector dependent dielectric function. The complex band structure of wurtzite GaN requires the inclusion of band-to-band tunneling effects that are critical at high electric fields. The electric-field-induced interband transitions are investigated by the direct solution of the time dependent multiband Schrodinger equation. The multiband description of the transport predicts a considerable increase in the impact ionization coefficients compared to the case in which tunneling is not considered. In the second part of this work it will be shown that the proposed numerical model correctly predicts the carrier multiplication gain and breakdown voltage of a variety of GaN avalanche photodetectors that have been recently fabricated by several research groups.
On the effect of gap width on the admittance of solid circular cylindrical dipoles

A center-fed, solid, circular cylindrical dipole of radius a with feed gap of width 2d radiating in a circular waveguide of radius b terminated in infinite ground planes is rigorously analyzed by applying both the conservation-of-complex-power technique and the multiple-reflections technique. The analysis begins by studying the dependence of the dipole admittance on its feed gap width and on its length, 2l, as well as on b, with ka (k=2 pi / lambda is the number) as a parameter. From the decreasing amplitudes of the almost periodic oscillations of these input admittances as b/ lambda is increased, the input admittances of dipoles radiating in free space (b to infinity ) are estimated using a variable-bound approach. The effect of gap width (d/a >
Numerical investigation of the radiation from an argon plasma generated by using a high explosive

Ultraviolet radiation from argon plasmas that are generated by using a high explosive were numerically investigated. The dynamics of the plasma was evaluated using a one-dimensional fluid code The chemical explosion was treated as an external ion-energy source in the region of the explosive, that generated a strong shock wave in the argon plasma with a peak pressure of 0.58 GPa. The population densities in the atomic levels of Ar I and Ar II were obtained in thermal equilibrium with the electron temperature of the plasma. Next, spectral data in the 200 nm to 800 nm wavelength range from the argon plasma were evaluated using a radiation transfer code. Atomic levels and transition lines were obtained from the database provided by the National Institute of Science and Technology. The total radiation intensity was estimated to be 4.1×102 J/cm2 with a conversion efficiency of 0.11%, from the chemical energy of the explosive for the case of a 1-cm-long high explosive and an initial pressure of 2.0 atm.
Asymptotic inference for near unit roots in spatial autoregression

Asymptotic inference for estimators of (α n , β n ) in the spatial autoregressive model z ij (n) = α n z i-1 , j (n) + β n Z i,j-1 (n) - α n β n Z i-1 , j-1 (n) + e ij obtained when α n and β n are near unit roots. When α n and β n are reparameterized by α n = e c/n and β n = e d/n , it is shown that if the one-step Gauss-Newton estimator of λ 1 α n + λ 2 β n is properly normalized and embedded in the function space D([0,1] 2 ), the limiting distribution is a Gaussian process. The key idea in the proof relies on a maximal inequality for a two-parameter martingale which may be of independent interest. A simulation study illustrates the speed of convergence and goodness-of-fit of these estimators for various sample sizes.
The flow due to a two-dimensional jet issuing parallel to a flat plate

An experiment has been performed to determine the cavity pressure and cavity length for the flow under a curved two-dimensional turbulent jet discharging parallel to a flat plate at some distance from the surface. The measurements agree quite closely with the predictions of a simple analysis of the flow when a value is assigned to the spread parameter for the curved jet which is somewhat different from that for the plane jet. Detailed pressure and velocity measurements show that the rate of growth of the curved jet is in fact closely similar to that of the plane jet. This suggests that the adjustment of the spread parameter should be regarded simply as a convenient device for taking into account the quantitative errors of the assumptions made in the analysis.
An asymptotic analysis of the scattering of plane waves by a smooth convex cylinder

An approximate asymptotic high-frequency result which is convenient for engineering applications is obtained for the field exterior to a smooth perfectly conducting convex cylinder when it is illuminated by a plane wave. This result is uniform in the sense that it remains valid within the transition regions adjacent to the shadow boundaries where the pure ray optical solution based on the geometrical theory of diffraction (GTD) fails, and it automatically reduces to the GTD solution exterior to the transition regions where the latter solution becomes valid. Furthermore, this result is expressed in the simple format of the GTD, and it employs the same ray paths as in the GTD solution. This uniform result is not valid in the close neighborhood of the cylinder; hence a separate asymptotic result is presented for this special case in a form which is also convenient for applications. The asymptotic results presented here are useful for predicting the patterns of antennas radiating in the presence of convex conducting cylindrical structures.
In situ energy-dispersive x-ray diffraction system for time-resolved thin-film growth studies

Energy-dispersive x-ray diffraction (EDXRD) with synchrotron light can be used for in situ-structural analysis during polycrystalline thin-film growth, due to its fast data collection and the fixed diffraction angle. An in situ deposition and analysis set-up for the investigation of nucleation and growth of thin films during magnetron sputtering was constructed and installed at the synchrotron radiation source Hamburger Synchrotronstrahlungs Labor (Hamburg). The polychromatic synchrotron beam passes the sputtering chamber through Kapton windows and hits the substrate with the growing film. The diffracted beam, observed under a fixed diffraction angle of between 1° and 10° was energy-analysed by a high-purity germanium detector. The measurement time for a single XRD spectrum can be as short as 10 s for a beam line at a bending magnet, which allows a time-resolved monitoring of film growth. The performance of the in situ EDXRD set-up is demonstrated for the growth of zinc oxide and tin-doped indium oxide films prepared by reactive magnetron sputtering from ceramic and metallic targets. From the position and the width of the diffraction lines the internal mechanical strain and the grain size of the growing films can be derived. The prospects for thin-film growth investigations using such an instrument are assessed.
On some new non-linear diffusion models for the image filtering

The paper deals with some new non-linear diffusion models, involving very general growth condition with respect to for the image filtering in the framework of Orlicz–Musielak spaces. We prove the existence of a solution in BV which is an adequate space for image processing tasks. The experimental results focus on giving a comparison with two Perona–Malik models.
ZnIr2O4, a p-type transparent oxide semiconductor in the class of spinel zinc-d6-transition metal oxide

The authors report on the growth of spinel ZnMd62O4 M=Co, Rh, and Ir, a ρ-type wide band gap semiconductor by pulsed laser deposition. The band gap of these compounds is determined by the ligand field splitting in the subbands of the metallic d6 cation. Photoemission spectroscopy revealed that the valence band maximum is composed of occupied t2g 6 states. The observed band gap is increasing for higher quantum numbers, being as large as 3 eV for ZnIr2O4, which is expected from theoretical predictions. Grown in polycrystalline phase, films of these materials display high conductivity, well above 2 S cm−1.
Reliability of thermal conductivity measurement of liquids by using transient hot-wire, photon-correlation spectroscopy and the laser flash method

Measuring the thermal conductivity of liquids is important, but not easy, because of the complexity of and the natural convection in liquids, and reliable thermal conductivity measurements in liquids under various sample conditions is essential for data accuracy. We have introduced and developed a validation chain for measuring the thermal conductivity of liquids by using three different experimental methods: the transient hot-wire (THW), the photon correlation spectroscopy (PCS) and the laser flash (LF) methods in the temperature range from −30 to 90 °C. We checked the performance of the validation chain developed in this study by measuring the thermal conductivity of liquid toluene. We found good agreement between the thermal conductivity data obtained by using the THW, PCS and LF methods. To demonstrate the use of this validation chain for measurements of thermophysical properties in liquids, we also showed its use in measuring the specific heat of a volatile liquid, toluene which can be extracted from thermal conductivity, thermal diffusivity, and density measurements without any effects of volatilization.
Obtaining and Verifying High-Order Unstructured Finite Volume Solutions to the Euler Equations

Interest in high-order unstructured-mesh finite volume methods continues to grow, as researchers are attracted both to the possibilities of high-accuracy solutions on coarse meshes and to applications for which high-order accuracy is all but mandatory, including large-eddy simulations for complex geometries. A major obstacle for those interested in developing a high-order solver, however, is that there are many more details that must be exactly right for a nominally-high-order scheme to be genuinely-high-order than for a second-order scheme to be second-order. In many cases, these details are either omitted or glossed over in the literature. This paper attempts to close this gap by illuminating a number of obscure, or often overlooked, aspects of correctly implementing a high-order-accurate unstructured-mesh finite volume solver. We discuss reconstruction, flux integration, curved-boundary treatment, and demonstrating order of accuracy. In each case, we describe test cases that are appropriate for confirming the correct behavior of a high-order code, as well as demonstrating some of the common pitfalls in implementation and showing their effects. We hope that this paper will serve other researchers as a practical guide to creating their own high-order-accurate solvers.
Latent Variable Theory

This paper formulates a metatheoretical framework for latent variable modeling. It does so by spelling out the difference between observed and latent variables. This difference is argued to be purely epistemic in nature: We treat a variable as observed when the inference from data structure to variable structure can be made with certainty and as latent when this inference is prone to error. This difference in epistemic accessibility is argued to be directly related to the data-generating process, i.e., the process that produces the concrete data patterns on which statistical analyses are executed. For a variable to count as observed through a set of data patterns, the relation between variable structure and data structure should be (a) deterministic, (b) causally isolated, and (c) of equivalent cardinality. When any of these requirements is violated, (part of) the variable structure should be considered latent. It is argued that, on these criteria, observed variables are rare to nonexistent in psychology; hence, psychological variables should be considered latent until proven observed.
The Euler-Maclaurin expansion for the simplex

A natural extension of the one-dimensional trapezoidal rule to the simplex 0 _ xi _ 1, E xi < 1, is a rule Rf which uses as abscissas all those points on a hyper- rectangular lattice of spacing h = 1/m which lie within the simplex, assigning an equal weight to each interior point. In this paper, rules of this type are defined and some of their properties are derived. In particular, it is shown that the error functional satisfies an Euler- Maclaurin expansion of the type Rf - If - Aih + A2h2 + * + Aphv + O(hv+') so long as f(x) and its partial derivatives of order up to p are continuous. Conditions under which this asymptotic series terminates are given, together with the condition for odd terms to drop out leaving an even expansion. The application to Romberg integration is discussed.
Electronic properties of a-CNx thin films : An x-ray-absorption and photoemission spectroscopy study

The electronic properties of amorphous carbon nitride were studied by x-ray-absorption near-edge structure (XANES) and valence-band photoelectron spectroscopy (PES). The nitrogen incorporation was found to induce graphitization, as evidenced by an increase of the sp2 cluster in C and N K-edge XANES spectra. The structure is found to be similar to pyridine. Hybridized C–N bond lengths were determined from the position of the σ* resonance of XANES spectra and the obtained results suggest sp2 hybridization. A valence-band PES spectrum showed that the p‐π band became more intense than the p‐σ band upon higher at. % nitrogen addition, which confirmed the role played by the π bonds in controlling the electronic structure of a‐CNx films.
Stellar weak-interaction rates for sd-shell nuclei. I - Nuclear matrix element systematics with application to Al-26 and selected nuclei of importance to the supernova problem

Astrophysical positron emission, continuum electron capture, and neutrino energy loss rates are calculated for 26 A1—> 26 Mg, 30 P—» 30 Si, 31 S—> 31 P, 32 S—> 32 P, 33 S-> 33 P, and 35 C1-* 35 S. Measured nuclear level information and matrix elements are used where available. Unmeasured matrix elements for allowed transitions are assigned on the basis of simple shell model arguments and the results of detailed large-scale shell model calculations by Wildenthal and his collaborators. The experimentally determined matrix elements are found to dominate the rates over most of the range of temperatures and densities considered. The uncertainties in the rates are estimated. Appropriate average matrix elements for unmeasured Gamow-Teller transitions are estimated for use in other ¿¿/-shell nuclei. The rates presented agree roughly with those of Hansen over a wide range of conditions, but potentially important differences in the rates exist at temperatures and densities relevant for the production and destruction of 26 A1 and for neutronization and neutrino loss in the late stages of presupemova evolution.
Complex general Fourier variational method applied to the analysis of semiconductor lasers

The generalised Fourier variational (GFV) method is implemented for the analysis of optoelectronic structures incorporating two new features: multiple layers and complex refractive indices. This extended method is validated by calculating complex propagation constants for commonly occurring types of index-guided laser geometries. The method produces highly accurate complex results by simple means, and is very fast.
A Unifying Framework for Classification and Interpretation of Mechanism Singularities

This paper presents a generalized approach to the singularity analysis of mechanisms with arbitrary kinematic chains and an equal number of inputs and outputs. The instantaneous kinematics ofa mechanism is described by means of a velocity equation, explicitly including not only the input and output velocities but also the passive-joint velocities. A precise definition of singularity of a general mechanism is provided. On the basis of the six types of singular configurations and the motion space interpretation of kinematic singularity introduced in the paper, a comprehensive singularity classification is proposed.
The EC 14026 stars -- X. A multi-site campaign on the sdBV star PG 1605+072

Results are reported from a multi-site photometric campaign on PG 1605+072, a member of the recently discovered class of pulsating hot subdwarfs, or EC 14026 stars. The main part of the campaign covered two weeks and produced ∼ 180 h of photoelectric photometry from the five sites involved. Periodogram analysis shows that the light curve is dominated by five frequencies in the range 1.89--2.74 mHz (periods 529--365 s) with the main frequency at 2.075 76 mHz (481.75 s), though there appear to be more than 50 frequencies identifiable down to a semi-amplitude of 0.0007 (in fractional intensity) in the range 1.74--4.84 mHz (573--206 s). Compared with other pulsating sdB stars, the low gravity (log g= 5.25) and long periods indicate that the star has evolved away from the core helium-burning horizontal branch. A preliminary model of a post-horizontal-branch star with appropriate parameters yields many pulsation periods in the range 300--600 s, but detailed mode identification is not possible at present.
MiCPhot: A prime-focus multicolor CCD photometer on the 85-cm Telescope

We describe a new BV RI multicolor CCD photometric system situated at the prime focus of the 85-cm telescope at the Xinglong Station of NAOC. Atmospheric extinction effects, photometric accuracy and color calibration dependence of the system are investigated. Additional attention was paid to giving observers guidance in estimating throughput, detection limit, signal-to-noise ratio and exposure time.
The Chemical Abundances of the Hydrogen-Poor Planetary Nebulae A30 and A58

We present new CCD narrowband images and spatially resolved intermediate-dispersion spectroscopy of the hydrogen-poor nebulae A30 and A58. These data have allowed us to obtain information on the physical properties and chemical abundances of the inner knots and outer envelopes of A30 and A58 as a basis for the discussion of their implications in the evolutionary theories. In particular, hydrogen emission from the central knots has been carefully measured, and, consequently, the rates of conversion of hydrogen into helium have been established with accuracy. The rates found indicate that almost all the original hydrogen (between 75% and 95%) has been burned into helium. The chemical segregation among the knots of A30 previously suggested by Jacoby & Ford is confirrmed. The A58 inner knot, which is spatially resolved in two different components, shows evidence of excitation by shocks. Helium abundances and the N/O ratio in the outer envelope of this nebula are very high, therefore indicating that the nebula formed as the result of the evolution of an intermediate-mass star. An analysis of the chemical abundances, including other objects of the same class, gives some hints that He/H and O/H are anticorrelated. The time elapsed between the formation of the outer envelopes and the ejection of the central knots also seems to be related to the central knotsi chemical abundances.