Miracle-dz/UniFAR-FTUs huggingface dataset:
Magnetic properties of Fe 2 O 3 (0001) thin layers studied by soft x-ray linear dichroism

X-ray magnetic linear dichroism (XMLD) at the Fe ${L}_{2}$ absorption edge has been used for investigating the magnetic properties of thin epitaxial $\ensuremath{\alpha}\ensuremath{-}{\mathrm{Fe}}_{2}{\mathrm{O}}_{3}$ layers (20 and 80 \AA{} thick). When cooling below 263 K, bulk hematite undergoes a 90\ifmmode^\circ\else\textdegree\fi{} rotation of the antiferromagnetic axes from perpendicular to parallel to the c axis (Morin transition). The ${L}_{2}\ensuremath{-}\mathrm{XMLD}$ results indicate that the 80-\AA{}-thick layer does not undergo such a transition at least down to 125 K. This absence is attributed to important magnetoelastic interactions due to the 0.3% expansion of the lattice parameter in the c plane. In the case of a 20-\AA{}-thick layer, we do not detect any ${L}_{2}\ensuremath{-}\mathrm{XMLD}$ signal, regardless of the temperature. The absence of antiferromagnetic ordering might be caused by the combined effect of several factors: finite size effects, changes in the local crystal field of the ${\mathrm{Fe}}^{3+}$ ion, and magnetoelastic interactions, coming from the 0.8% expansion of the lattice parameter in the c-plane.
Assessment of Shortwave Infrared Sea Surface Reflection and Nonlocal Thermodynamic Equilibrium Effects in the Community Radiative Transfer Model Using IASI Data

AbstractThe nadir-viewing satellite radiances at shortwave infrared channels from 3.5 to 4.6 μm are not currently assimilated in operational numerical weather prediction data assimilation systems and are not adequately corrected for applications of temperature retrieval at daytime. For satellite observations over the ocean during the daytime, the radiance in the surface-sensitive shortwave infrared is strongly affected by the reflected solar radiance, which can contribute as much as 20.0 K to the measured brightness temperatures (BT). The nonlocal thermodynamic equilibrium (NLTE) emission in the 4.3-μm CO2 band can add a further 10 K to the measured BT. In this study, a bidirectional reflectance distribution function (BRDF) is developed for the ocean surface and an NLTE radiance correction scheme is investigated for the hyperspectral sensors. Both effects are implemented in the Community Radiative Transfer Model (CRTM). The biases of CRTM simulations to Infrared Atmospheric Sounding Interferometer (IASI) .
Baroclinic instability in a two‐layer, vertically semi‐infinite domain

A quasi-geostrophic two-layer system with uniform, but different, shears and stratifications in two layers is examined for the occurrence of baroclinic instability. A derived necessary condition for instability requires that the shear in the upper, semi-infinite layer does not exceed a certain value (related to the stratification). For each configuration of the basic flow, there appear two short and two long neutral modes as well as a decaying and a growing mode at intermediate wavelengths. The short neutral modes are bound to either the surface or the interface, the long neutral modes to one or other of the layers. Instability appears if the foregoing modes propagate at a similar velocity. The depth of the waves is shown to be of less importance in the framework of potential vorticity dynamics. For some configurations, the growth rates surpass those of the classical Eady problem. Finally some consideration is given to the linkage between these results and the formation of polar lows. DOI: 10.1034/j.1600-0870.1991. t01-4-00003.x
On the MIMO Channel Capacity for the Nakagami-m Channel

This paper presents the multiple-input multiple-output (MIMO) channel capacity over the Nakagami-m fading channel. The joint eigenvalue density function of W = HH' where H is the channel matrix, is derived in closed form for H (2 times 2) and any integer values of m, as well as for H (2 times 3) with to = 2 and to = 3. The marginal eigenvalue distribution of W is also derived in a closed-form expression. All the results are validated by numerical Monte Carlo simulations and are in excellent agreement.
Impact of the Electric Field on the Freezing Dynamics of Pb(Mg1/3Nb2/3)O3

The dielectric response of canonical relaxor PMN single crystal oriented in [111] direction was investigated under the influence of various dc bias electric fields. The behavior of the Vogel-Fulcher temperature obtained from the characteristic relaxation times determined from the peaks of the imaginary component ϵ″(T) of the complex dielectric constant ϵ*(T) was studied as a function of the dc bias electric field. The observed results reveal nonmonotonous behavior of the Vogel-Fulcher temperature as a function of the strength of the dc bias electric field. We show that such a behavior can be well interpreted in terms of nonlinear dielectric susceptibility as a dominant factor in the dielectric dynamic of relaxors in dc bias electric fields.
Simultaneous Variable Selection

We propose a new method for selecting a common subset of explanatory variables where the aim is to model several response variables. The idea is a natural extension of the LASSO technique proposed by Tibshirani (1996) and is based on the (joint) residual sum of squares while constraining the parameter estimates to lie within a suitable polyhedral region. The properties of the resulting convex programming problem are analyzed for the special case of an orthonormal design. For the general case, we develop an efficient interior point algorithm. The method is illustrated on a dataset with infrared spectrometry measurements on 14 qualitatively different but correlated responses using 770 wavelengths. The aim is to select a subset of the wavelengths suitable for use as predictors for as many of the responses as possible.
Light and voltage noise of lasers based on AlxGa1–xAsGaAs heterojunctions

Light and voltage noise in AlxGa1–xAs–GaAs heterolasers are studied in a wide range of forward currents (i = 10−7 to 4 A) and frequencies (f = 1 to 107 Hz). The noise characteristics obtained are compared with those observed on GaAs laser diodes. Results of investigations carried out on samples of both types are similar. Components of 1/f-type are found in the spectra of light noise as well as in the spectra of voltage noise. At currents below the threshold value, these components are correlated with each other and are due to the fluctuations of the nonradiative component of the diode current. The reasons for the changes in the 1/f-noise which take place at the sample change-over to the laser action are discussed. As the change-over to the laser action occurs, the sharp increase of frequency-independent high-frequency light and voltage noise predicted by the theory is found experimentally. These noises appear to be fully correlated with each other, the phase shift between the fluctuations of light and of voltage on the diode contacts being equal to 180°. In addition, the change of the noise characteristics taking place in the course of diode operation is disclosed and analysed. As a result a connection is established between the processes of the slow laser degradation and the peculiarities of the excess component of the diode current as well as of its low-frequency noise. [Russian Text Ignored].
Transport of a passive scalar at a shear-free boundary in fully developed turbulent open channel flow

Direct numerical simulations of fully developed turbulence in an open channel geometry were performed in which a passive scalar was introduced. The simulations were intended to explore transport at free surfaces in two cases for which (1) the free surface was maintained at constant temperature and (2) the interfacial flux was fixed. These cases can be considered models for mass and evaporative heat transport where buoyancy and surface deformation effects are negligible. Significant differences were found in the thermal fields in these two cases. The turbulent statistics reveal that the surface flux in the constant temperature case was significantly more intermittent compared to the surface temperature field in the constant flux case. The surface temperature field in the latter case formed large patches of warm fluid, reminiscent of the so-called fish scale patterns revealed in recent infrared imagery of the air–water interface. The wake-like structure of the patches was evident despite the absence of surf.
Self-proton/ion radiography of laser-produced proton/ion beam from thin foil targets

Protons and multicharged ions generated from high-intensity laser interactions with thin foil targets have been studied with a 100 TW laser system. Protons/ions with energies up to 10 MeV are accelerated either from the front or the rear surface of the target material. We have observed for the first time that the protons/ions accelerated from the front surface of the target, in a direction opposite to the laser propagation direction, are turned around and pulled back to the rear surface, in the laser propagation direction. This proton/ion beam is able to create a self-radiograph of the target and glass stalk holding the target itself recorded through the radiochromic film stack. This unique result indicates strong long-living (ns time scale) magnetic fields present in the laser-produced plasma, which are extremely important in energy transport during the intense laser irradiation. The magnetic field from laser main pulse expands rapidly in the preformed plasma to rotate the laser produced protons. Radiati.
Numerical Simulation of a Liquid Drop Freely Oscillating

Free oscillations of a viscous liquid drop surrounded by a dynamically inactive ambient gas, in zero gravity, are investigated numerically using FIDAP TM package in the axisymmetrical case. The full Navier-Stokes equations with appropriate interfacial conditions are solved by using Galerkin/Finite element technique along with the spine method for the advection of the free boundary are used. The aim of this preliminary study is to demonstrate the ability of the package to accurately solve nonlinear free surface problems. Oscillations of viscous drops released from an initial static deformation of small-to large-amplitude proportional to the second spherical harmonic, without initial internal circulation, are considered
Sea surface freshwater flux estimates from GECCO, HOAPS and NCEP

Abstract Surface net freshwater flux fields, estimated from the GECCO ocean state estimation effort over the 50 yr period 1951–2001, are compared to purely satellite-based HOAPS freshwater flux estimates and to the NCEP atmospheric re-analysis net surface freshwater flux fields to assess the quality of all flux products and to improve our understanding of the time-mean surface freshwater flux distribution as well as its temporal variability. Surface flux fields are adjusted by the GECCO state estimation procedure together with initial temperature and salinity conditions so that the model simulation becomes consistent with ocean observations. The entirely independent HOAPS net surface freshwater flux fields result from the difference between SSM/I based precipitation estimates and fields of evaporation resulting from a bulk aerodynamic approach using SSM/I data and the Pathfinder SST. All three products agree well on a global scale. However, overall GECCO seems to have moved away from the NCEP/NCAR first guess surface fluxes and is often closer to the HOAPS data set. This holds for the time mean as well as for the seasonal cycle.
Variable accretion of stellar winds onto Sgr A

We report a 3-dimensional numerical study of the accretion of stellar winds onto Sgr A*, the super-massive black hole at the centre of our Galaxy. Compared with previous investigations, we allow the stars to be on realistic orbits, include the recently discovered slow wind sources, and allow for optically thin radiative cooling. We frst show the strong inflience of the stellar dynamics on the accretion onto the central black hole. We then present more realistic simulations of Sgr A* accretion and frid that the slow winds shock and rapidly cool, forming cold gas clumps and flaments that coexist with the hot X-ray emitting gas. The accretion rate in this case is highly variable on time-scales of tens to hundreds of years. Such variability can in principle lead to a strongly non-linear response through accretion fbw physics not resolved here, making Sgr A* an important energy source for the Galactic centre.
Approximate Entropy as an Irregularity Measure for Financial Data

The need to assess subtle, potentially exploitable changes in serial structure is paramount in the analysis of financial and econometric data. We demonstrate the utility of approximate entropy (ApEn), a model-independent measure of sequential irregularity, towards this goal, via several distinct applications, both empirical data and model-based. We also consider cross-ApEn, a related two-variable measure of asynchrony that provides a more robust and ubiquitous measure of bivariate correspondence than does correlation, and the resultant implications to diversification strategies. We provide analytic expressions for and statistical properties of ApEn, and compare ApEn to nonlinear (complexity) measures, correlation and spectral analyses, and other entropy measures.
Hybrid simplex search and particle swarm optimization for the global optimization of multimodal functions

This article proposes the hybrid Nelder–Mead (NM)–Particle Swarm Optimization (PSO) algorithm based on the NM simplex search method and PSO for the optimization of multimodal functions. The hybrid NM–PSO algorithm is very easy to implement, in practice, since it does not require gradient computation. This hybrid procedure performed the exploration with PSO and the exploitation with the NM simplex search method. In a suite of 17 multi-optima test functions taken from the literature, the computational results via various experimental studies showed that the hybrid NM–PSO approach is superior to the two original search techniques (i.e. NM and PSO) in terms of solution quality and convergence rate. In addition, the presented algorithm is also compared with eight other published methods, such as hybrid genetic algorithm (GA), continuous GA, simulated annealing (SA), and tabu search (TS) by means of a smaller set of test functions. On the whole, the new algorithm is demonstrated to be extremely effective and efficient at locating best-practice optimal solutions for multimodal functions.
Picosecond hot electron light emission from submicron complementary metal–oxide–semiconductor circuits

Optical emission consisting of pulses with temporal widths of less than 270 ps has been detected from fully functional silicon integrated circuits fabricated using submicron complementary metal– oxide–semiconductor (CMOS) logic gates. Emission is observed under normal bias conditions and occurs when the gates are switching. The emission arises from the hot electron populations created by the transient current pulses present in the transistors during switching. The speed and spectral characteristics of the emission suggest future applications in the measurement of timing in high speed CMOS circuits.
Exploring the effect of intellectual capital management on innovativeness in an R&D institute Badanie wpływu zarządzania kapitałem intelektualnym

The literature that empirically investigates the relationship between intellectual capital management and innovativeness in R&D institutions is scarce. In addition, no sources have been found to extend the analysis to include the technological orientation as a strategic approach to developing innovative capabilities. This study builds on the theoretical premises of the intellectual capital-based view of the firm and the dynamic capabilities view. This paper addresses a research gap, by setting out to study the impact of intellectual capital management on innovativeness in an R&D institute, while also considering the relationship with technological orientation. It is proposed that intellectual capital management, through its components human, structural and relational capital positively affect innovativeness in an R&D institute. Moreover, it is hypothesized that human capital and innovativeness positively affect innovativeness in an R&D institute. The research employs PLS-SEM analysis on data collected from a sample of (N = 61) employees of an R&D institute. Data has been acquired by means of a questionnaire measuring intellectual capital management through human, structural and relational capital components, as well as innovativeness and technological orientation. Findings confirm significant direct effects of structural and relational capital on innovativeness, as well as the positive direct effect of human capital and innovativeness on technological orientation. This research represents an original contribution to the academic literature, by bringing new evidence concerning the relationships between intellectual capital management, innovativeness and technological orientation in an R&D institute in Eastern Europe.
Prediction for spatio-temporal models with autoregression in errors

In various environmental studies spatio-temporal correlated data are involved, so there has been an increasing demand for spatio-temporal prediction methods that capture spatio-temporal correlation so as to improve the accuracy of prediction. In this paper we propose a nonparametric iteration procedure for spatio-temporal models with specific autocorrelation structures. We extended the local linear method for spatial data to spatio-temporal local linear models, taking both spatial and temporal characteristics into consideration. The asymptotic normality of the predictors is established under mild conditions. The results of a simulation and case study also show that our predictors perform better than the traditional local linear method.
Free living ciliated protists from the chemoautotrophic cave ecosystem of Frasassi (Italy)

This study provides the first report on a community of free-living ciliated protists from the chemoautotrophic cave ecosystem of Frasassi, Italy. This subterranean groundwater ecosystem represents a hotspot of biodiversity that still needs to be fully explored with particular reference to microbial eukaryotes such as protist ciliates. A total of 33 taxa of ciliates were identified along with one species each of flagellate, heliozoans and naked amoebae, from four main sampling sites, namely, Grotta Solfurea (GSO), Lago Verde (LVE), Ramo Solfureo (RSO), and Pozzo dei Cristalli (PDC). The last consists of small microhabitats/ponds presenting different chemical–physical and biological parameters, such as sulfur and nutrient contents and the presence of bacterial biofilms. Furthermore, an analysis of the cryptic ciliate species biosphere as a ‘seedbank’ of diversity against cave ecosystem disturbance was also performed. This study also highlights some peculiar adaptations of cave-dwelling ciliates not described in their noncave-dwelling conspecifics, such as the extreme photosensitivity of Urocentrum turbo , the cannibalism of Coleps hirtus , the variable number of thorns in Aspidisca species as a defensive response to predation, and the frequent reorganization of ciliary structures in Euplotes aediculatus . The 18S rDNA sequences were generated for five species and were compared with those of the noncave-dwelling conspecifics. Finally, our results shed light on the still largely unknown ciliate diversity in the chemosynthesis-based sulfidic groundwater ecosystem of Frasassi.
Beyond Brownian motion

Newtonian physics began with an attempt to make precise predictions about natural phenomena, predictions that could be accurately checked by observation and experiment. The goal was to understand nature as a deterministic, “clockwork” universe. The application of probability distributions to physics developed much more slowly. Early uses of probability arguments focused on distributions with well‐defined means and variances. The prime example was the Gaussian law of errors, in which the mean traditionally represented the most probable value from a series of repeated measurements of a fixed quantity, and the variance was related to the uncertainty of those measurements.
AN EXPERIMENTAL STUDY OF PAPER FLUTTER

An experimental study was conducted in order to clarify the phenomenon of paper flutter. Flutter speed was measured in wind tunnel tests for sheet paper and web paper of various materials, sizes and tensions. The relationships between flutter speed, rigidity, mass ratio and tension were clarified from a large data set. The flutter boundaries were obtained in the form of dimensionless flutter speed and mass ratio for the case of sheet paper, and dimensionless flutter speed, mass ratio and tension parameter for the case of web paper. The flutter mode and air-flow around fluttering paper were investigated by visualization tests.
Changing Mode of Regulation: Role Models in Moral Education Textbooks for Primary Schools in China, 1999–2005

The use of role models for learning and publicity is widespread in China. By comparing four sets of primary school textbooks complied and published by People’s Education Press between 1999 and 2005, this study reveals the similarities and differences between these textbooks with regard to the positive role models covered and the virtues conveyed. The major role models in both versions of the textbooks can be characterized as representing four main types of persons: children, Han Chinese, males, and modern people. However, the occupations of these role models are more diverse in the new textbooks, and the more recent editions place more emphasis on moral values such as “protecting the environment,” “loving peace,” and “promoting democratic cooperation. ” The implications of the findings and the potential problems arising in the textbooks are discussed at the end, particularly noting the changing mode of regulation with regard to the individual-collective relationship.
One Loop Renormalization of Quantum Electrodynamics in Curved Space-time

In this paper we discuss the renormalizability of quantum electrodynamics (QED) in a general curved space-time. A generating functional is introduced and position-space Feynman rules are obtained. Functional techniques are used to show that a form of Ward's identity can be derived in curved space-time. A local momentum representation for the scalar and vector propagators is introduced. The one-loop diagrams for the electron and photon self-energy are computed and it is shown that there are no divergences that are not present in flat space. It is shown that this latter result depends crucially on the gauge invariance of the theory and is not merely a trivial consequence of renormalizability of QED in flat space-time.
Moderate deviations for traces of words in a mult-matrix model

We prove a moderate deviation principle for traces of words of weakly interacting random matrices defined by a multi-matrix model with a potential being a small perturbation of the GUE. The remarkable strength of high order expansions of the matrix model recently found by Guionnet and Maurel-Segala is the key fact that allows us to develop our result and provides also an alternative proof for a special case of the central limit theorem for traces of words, studied in the article of Guionnet and Maurel-Segala (2006).
Bayesian Design of “Successful” Replications

Replication of experiments is commonin applied research. However, systematic studies of the goals and motivations of a “replication” are rare. As a consequence, there does not seem to be a precise notion of what a “success” when replicating means. This article discusses some of the possible goals for replication; this leads to different (but precise) notions of “success” when replicating. Bayesian hierarchical models allow for a flexible and explicit incorporation of the assumed relationship among the experiments. Bayesian predictive distributions are a natural tool to compute the probability of the replication being successful, and hence to design the replication so that the probability of success is high enough. Derivations are exemplified with data coming from a noncentral t distribution.