Miracle-dz/UniFAR-FTUs huggingface dataset:
Time-resolved and energy-dispersed spin excitation in ferromagnets and clusters under influence of femtosecond laser pulses

When an ultrafast laser impinges a magnetic material, it excites charge and then, via spin-orbit-coupling, spin. This holds great promise for the future magnetic storage. However, the coupling of the two dynamics is far from clear, which hampers the experimental effort in femtosecond magnetism. Since not every excitation induces the same spin excitation, a clear understanding of the correlation between charge and spin is crucial. In this paper we investigate in a complete first-principles manner the energy dispersion of the spin-moment change in ferromagnetic Ni and the effect of the distance between the magnetic centers upon the spin localization and local-spin-flip times in metallic chains. Thus we establish the missing link between the spin-momentum change and the density-of-states change, and derive rules-of-thumb for localized spin manipulation.
Simulations of Particle Dispersion around Multiple Circular Cylinders via an Immersed Boundary Method

A modified immersed boundary method is extended to study fine particle dispersion in particle-laden wake flows around multiple stationary circular cylinders, with a Reynolds number of 250. The fixed Cartesian grid is applied and the no-slip condition near the surface of circular cylinders is satisfied through a direct forcing technique. The governing equations for fluid flow are directly solved using high-order finite difference schemes and the dispersed fine particles are tracked in the Lagrangian framework based on point-source assumption. The numerical algorithms are first validated by simulating flows around a single circular cylinder. For flows around two side-by-side circular cylinders, three typical flow regimes are observed for different gap ratios. For flow around three staggered circular cylinders, the coherent structures first appear in symmetrical mode with large recirculation zones, but then change to asymmetrical mode and finally develop into a complex single vortex street. The particle disp.
Large-eddy simulation of high-Schmidt number mass transfer in a turbulent channel flow

Mass transfer through the solid boundary of a turbulent channel flow is analyzed by means of large-eddy simulation (LES) for Schmidt numbers Sc=1, 100, and 200. For that purpose the subgrid stresses and fluxes are closed using the Dynamic Mixed Model proposed by Zang et al. [Phys. Fluids A 5, 3186 (1993)]. At each Schmidt number the mass transfer coefficient given by the LES is found to be in very good quantitative agreement with that measured in the experiments. At high Schmidt number this coefficient behaves like Sc−2/3, as predicted by standard theory and observed in most experiments. The main statistical characteristics of the fluctuating concentration field are analyzed in connection with the well-documented statistics of the turbulent motions. It is observed that concentration fluctuations have a significant intensity throughout the channel at Sc=1 while they are negligible out of the wall region at Sc=200. The maximum intensity of these fluctuations depends on both the Schmidt and Reynolds numbers .
Online independent Lagrangian support vector machine

In this paper, a novel incremental learning method called online independent Lagrangian support vector machine (OILSVM) is proposed. It achieves comparable classification accuracy with benchmark Lagrangian support vector machine (LSVM), while still enjoying the time efficiency of online learning machines. As opposed to the newly proposed OLSVM that utilizes the KKT conditions as data selection strategy, the size of the solution obtained by OILSVM using a linear independence check is always bounded, which implies bounded memory requirements, training and testing time. Experimental results demonstrate the effectiveness of the proposed OILSVM.
RETRACTED: Optimization method of emergency logistics network in the initial post-earthquake stage considering multiple factors and the case analysis

Junxiang Xua,∗, Jingni Guoa, Jin Zhanga,b,c, Yongdong Suna, Weihua Liud and Hui Mad aSchool of Transportation and Logistics, Southwest Jiaotong University, Chengdu, China bNational United Engineering Laboratory of Integrated and Intelligent Transportation, Southwest Jiaotong University, Chengdu, China cNational Engineering Laboratory of Integrated Transportation Big Data Application Technology, Chengdu, China dChina Railway No. 2 Engineering Group Co., LTD, Chengdu, China
Experiments on Plasma Turbulence Created by Supersonic Plasma Flows with Shear

Abstract : The turbulence created by streaming ions through a stationary plasma has been studied. The velocity of the streaming ions was selected via a biasing voltage. In situ probes were used to measure the local and time-varying plasma parameters, ion distribution functions, and the turbulence itself. Density fluctuations were recorded in time and space, Fourier transformed into frequency space and cross-correlated in space. The fluctuations were identified as ion sound modes and their growth rate was shown to depend on the beam energy. The interaction of density fluctuations with electromagnetic waves was investigated. Strong scattering of electromagnetic signals was observed when the wave was guided by a transmission line through a turbulent plasma. The effect was enhanced by forming a transmission line resonator and applying frequencies on the slope of the resonance curve. This suggests a method to eliminate the modulation of a high frequency signal by plasma turbulence. In addition a new method of generating plasma flows with shear has been devised. It is based on creating electron MHD flows with pulsed magnetic fields. Shear flow ion acoustic turbulence has been observed. The work also inspired new methods for eliminating the blackout problem.
Lip Stall Suppression in Powered Intakes

This work describes a computational study into lip stall in subsonic civil aircraft intakes and its alleviation by action of the fan. Beyond a certain flow incidence, the lower lip of a civil aircraft intakes stalls. This phenomenon causes entropy and vortical distortions at the fan face. Consequently, it has detrimental effects on vibration levels and performance of the low-pressure compressor system. The most important parameters influencing lip separation are the flight Mach number, the Reynolds number, and altitude. Fully three-dimensional simulations have been performed on a flight intake in current service for which the experimental data are available. Steady and time-resolved simulations have been performed. Distortion coefficients have been evaluated as functions of incidence and have been compared with experimental results. A comparison between an isolated intake and a powered intake shows that the fan stage has the beneficial effect of increasing tolerance to flow incidence and decreasing distor.
Electromagnetic modeling of three-dimensional bodies in layered earths using integral equations

We have developed an algorithm based on the method of integral equations to simulate the electromagnetic responses of three‐dimensional bodies in layered earths. The inhomogeneities are replaced by an equivalent current distribution which is approximated by pulse basis functions. A matrix equation is constructed using the electric tensor Green’s function appropriate to a layered earth, and it is solved for the vector current in each cell. Subsequently, scattered fields are found by integrating electric and magnetic tensor Green’s functions over the scattering currents. Efficient evaluation of the tensor Green’s functions is a major consideration in reducing computation time. We find that tabulation and interpolation of the six electric and five magnetic Hankel transforms defining the secondary Green’s functions is preferable to any direct Hankel transform calculation using linear filters. A comparison of responses over elongate three‐dimensional (3-D) bodies with responses over two‐dimensional (2-D) bodie.
Noncollinear magnetic order in the S=(1)/(2) magnet Sr 3 ZnRhO 6

The compound ${\mathrm{Sr}}_{3}{\mathrm{ZnRhO}}_{6}$ with $S=1/2$ belongs to a family of pseudo-one-dimensional (1D) spin-chain systems with general formula ${\mathrm{A}}_{3}{\mathrm{A}}^{\ensuremath{'}}{\mathrm{BO}}_{6}$. The nature of the ground state of ${\mathrm{Sr}}_{3}{\mathrm{ZnRhO}}_{6}$ is investigated using microscopic techniques such as muon spin relaxation ($\ensuremath{\mu}$SR) and powder neutron diffraction in addition to bulk characterization using magnetization, ac-susceptibility, and heat capacity. Our $\ensuremath{\mu}$SR study clearly reveals the presence of three frequencies, below 16 K, whose temperature dependence follow a mean-field order parameter indicating long-range magnetic ordering of the ${\mathrm{Rh}}^{4+}$ moment. Powder neutron diffraction reveals the presence of four weak magnetic Bragg peaks below 16 K, indexed by the propagation vector $\mathbf{k}=(0,\frac{1}{2},1)$ in the hexagonal setting of the space group $R\stackrel{\underline{}}{3}c$. Analysis of the magnetic diffraction pattern constrained to symmetry-adapted magnetic modes reveals a noncollinear magnetic structure with an ordered magnetic moment of ${\mathrm{Rh}}^{4+}=0.7(1)$ ${\ensuremath{\mu}}_{B}$. This is the first compound in this spin chain family which exhibits noncollinear magnetic order with the moment tilting away from the $c$ axis, highlighting the important role of interchain and intrachain interactions.
Nonoscillation criteria for second‐order nonlinear differential equations with decaying coefficients

This paper is concerned with the problem of deciding conditions on the coefficient q (t) and the nonlinear term g (x) which ensure that all nontrivial solutions of the equation (|x ′|α–1x ′)′ + q (t)g (x) = 0, α > 0, are nonoscillatory. The nonlinear term g (x) is not imposed no assumption except for the continuity and the sign condition xg (x) > 0 if x ≠ 0. In our problem, it is important to examine the relation between the decay of q (t) and the growth of g (x). Our main result extends some nonoscillation theorem for the generalised Emden–Fowler equation. Proof is given by means of some Liapunov functions and phase‐plane analysis. A simple example is includes to show that the monotonicity of g (x) is not essential in our problem. Finally, elliptic equations with the m ‐Laplacian operator are discussed as an application to our results. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A Second Order Approximation Technique for Robust Shape Optimization

We present a second order approximation for the robust counterpart of general uncertain nonlinear programs with state equation given by a partial di erential equation.We show how the approximated worst-case functions, which are the essential part of the approximated robust counterpart, can be formulated as trust-region problems that can be solved effciently using adjoint techniques. Further, we describe how the gradients of the worst-case functions can be computed analytically combining a sensitivity and an adjoint approach. This methodis applied to shape optimization in structural mechanics in order to obtain optimal solutions that are robust with respect to uncertainty in acting forces. Numerical results are presented.
Region-based non-local means algorithm for noise removal

The non-local means (NLM) provides a useful tool for image denoising and many variations of the NLM method have been proposed. However, few works have tried to tackle the task of adaptively choosing the patch size according to region characteristics. Presented is a region-based NLM method for noise removal. The proposed method first analyses and classifies the image into several region types. According to the region type, a local window is adaptively adjusted to match the local property of a region. Experimental results show the effectiveness of the proposed method and demonstrate its superiority to the state-of-the-art methods.
Measuring micro liquid volume by acoustic resonant technique

A method to measure micro liquid volume less than 300 ln with the accuracy of 0.1% is highly needed in biogenetic and biochemical industries. The authors propose a novel method to estimate micro liquid volume in a small well using acoustic resonance. In our experiments, liquid is in a container 6.5 mm in inner diameter and 9 mm in height, and the sound pressure near the well is measured by sweeping the illuminating sound field from 6 to 11 kHz. According to the relationship between the resonance frequency and the volume, we can successfully estimate the small volume with the accuracy of 0.1% and an excellent repeatability. For simultaneous multipoint measurements, we experimentally investigate the effect of adjacent wells on resonant frequency of the target well. It is revealed that the resonance frequency shift due to the mutual coupling between the adjacent wells is negligible if the well interval is less than 5 mm.
Polarization-Selective Coupling to Long-Range Surface Plasmon Polariton Waveguides

We demonstrate polarization-selective coupling from an optical fiber to long-range surface plasmon polariton waveguide modes using plasmonic antenna arrays. The arrays allow the sorting of two distinct (not necessarily orthogonal) polarizations to counter-propagating waveguide modes. The polarization-selective behavior of the devices is described by a compact formalism based on Stokes vectors that offers a clear graphical representation of the response. We experimentally observe polarization-controlled switching and unidirectional coupling with extinction ratios greater than 30 dB and coupling efficiencies comparable to those of a conventional grating coupler.
1'' Resolution Mapping of the Molecular Envelope of the Protoplanetary Nebula CRL 618

We present 1'' resolution interferometric maps of the CO J = 2-1 and HC3N J = 25-24 emission in the protoplanetary nebula CRL 618 obtained with the millimeter array of the Owens Valley Radio Observatory (OVRO). Our CO data trace with high accuracy the spatio-kinematic structure of different molecular components: (1) the fast, bipolar outflow, which is observed up to axial distances of ±2. ″5 (±2.7 × 1016 cm) from the nebula center with a maximal deprojected expansion velocity of Vexp ~ 340 km s-1; (2) the roughly round outer halo, which is slowly expanding at Vexp ~ 17 km s-1; (3) an extended structure that is elongated in the polar direction ±6'' (±8.1 × 1016 cm), surrounding the optical lobes, and that expands at Vexp ~ 22 km s-1 (slow axial component); and (4) a dense, inner torus-like core (Rout ~ 1.6 × 1016 cm) expanding at Vexp ≲ 12 km s-1. Components (3) and (4) have been revealed for the first time by our high angular resolution data. The geometry, kinematics, density, and temperature distribution of the individual components of the molecular envelope of CRL 618 have been constrained by fitting a spatio-kinematic model to the data. We interpret our results in terms of nebular evolution as follows. In the last ≳2500 yr, there have been at least two distinct episodes of mass loss at a large scale in the form of a slow wind. The first took place at a rate of ≲ 10-5 M☉ yr-1 and gave place to the tenuous outer halo. The second mass-loss event started ~400 yr ago at a higher rate of ≈ 10-4 M☉ yr-1, resulting in the formation of the inner dense core. More recently, the interaction between fast axial post-asymptotic giant branch (AGB) winds and the preexisting circumstellar envelope has shaped (i) the fast bipolar outflow, which is probably composed of shocked material that was originally in the inner dense core, and (ii) the slow axial component, which could represent material in the interface between the shocked and unshocked AGB envelope. Finally, we report a recent increase of the free-free continuum emission at 1.3 mm (2.1 ± 0.3 Jy) and 3 mm (2.3 ± 0.3 Jy), which could reflect changes in the activity of the fast post-AGB winds on a timescale of a few years.
Complex flow transitions in a homogeneous, concentrated emulsion

Results are presented for the flow of homogeneous, concentrated, oil-in-water emulsions subjected to a shear flow between rotating, horizontal concentric cylinders. Nuclear magnetic resonance imaging (NMRI) was used to measure velocity profiles. This technique allows velocity profiles to be measured noninvasively within a flowing, concentrated emulsion. It was observed that below a critical velocity, in a portion of the gap, the fluid moves in a direction opposite to the outer, rotating cylinder. Above this critical velocity, the emulsion corotates with the outer cylinder. Theoretical analysis suggests that the transitions are driven by buoyancy effects. The corotating and counter-rotating flow states at different rotation speeds can be characterized by a single dimensionless parameter Γ, which relates buoyancy and viscous effects.
Modified signed log likelihood ratio

SUMMARY The signed log likelihood ratio r for a one-dimensional interest parameter can be modified as r* = r + r-' log (u/r) so that r* is asymptotically standard normally distributed with error of order O(n-3/2), u being interpretable as a test statistic. A new, more direct derivation of this result is given, which leads to a more explicit expression for u and provides a better handle on the error term. The relation of the tail area approximation determined by r* to a generalization of the Lugannani-Rice approximation is discussed, and the applicability of r* to the analysis of residual variation is indicated.
Asymptotic Behaviour and Self-Similarity for the Three Dimensional Vlasov–Poisson–Fokker–Planck System

Abstract The aim of this work is to study the asymptotic behaviour of global in time solutions of the Vlasov–Poisson–Fokker–Planck system in three dimensions. We consider both cases, with gravitational and electrostatic interaction, but disregard friction. It is proved that the distribution of particles tends for large time to the fundamental solution of the linear operator in L 1 norm, which means that the effect of the interaction potential vanishes comparatively at t →∞. In quantitative terms the result assures that the total nonlinear interaction force decays for large time with a decay rate of order t −3 and the potential energy behaves like O ( t −3/2 ). The asymptotic result is independent of the repulsive or attractive character of the interaction field. The main idea is to use the self-similarity of the fundamental solution of the linear part of the equation and the regularity of the Fokker–Planck operator in order to study the large-time distribution of particles.
Estimating Averaging Times for Point and Path-Averaged Measurements of Turbulence Spectra

Abstract Uncertainty over how long to average turbulence variables to achieve some desired level of statistical stability is a common concern in boundary-layer meteorology. Several models exist that predict averaging times for measurements of variances and covariances, but often we are not interested in the low-frequency fluctuations that dominate variances and covariances. For example, we may want to look only at the inertial subrange. Therefore, a theoretical model is presented here to use in estimating the required averaging time for both point measurements and path-averaged electro-optical or acoustic measurements of the turbulence spectrum at arbitrary frequency f. The model is based on 1) the fact that spectral estimators and sample variances have chi-squared probability distributions; and 2) observations of the spectral coherence between horizontally separated turbulence sensors in the atmospheric boundary layer. This model is different from others that predict required averaging times because it y.
Studies in Spatial Motion of a Gyro on an Elastic Foundation

ABSTRACT To investigate the spatial motion of an axisymmetric gyro on an elastic foundation, a simplified model is proposed. The model is as simple as possible, yet designed to have all characteristics required to study its nonlinear behavior. Using Euler's law, the full nonlinear equations of motion are derived and then written in nondimensional form. Following analysis, numerical examples are investigated, and the evolution of nutation, precession, and spin angles is plotted.
ON THE NOTION OF WELL-DEFINED TECTONIC REGIMES FOR TERRESTRIAL PLANETS IN THIS SOLAR SYSTEM AND OTHERS

A model of coupled mantle convection and planetary tectonics is used to demonstrate that history dependence can outweigh the effects of a planet's energy content and material parameters in determining its tectonic state. The mantle convection-surface tectonics system allows multiple tectonic modes to exist for equivalent planetary parameter values. The tectonic mode of the system is then determined by its specific geologic and climatic history. This implies that models of tectonics and mantle convection will not be able to uniquely determine the tectonic mode of a terrestrial planet without the addition of historical data. Historical data exists, to variable degrees, for all four terrestrial planets within our solar system. For the Earth, the planet with the largest amount of observational data, debate does still remain regarding the geologic and climatic history of Earth's deep past but constraints are available. For planets in other solar systems, no such constraints exist at present. The existence of multiple tectonic modes, for equivalent parameter values, points to a reason why different groups have reached different conclusions regarding the tectonic state of extrasolar terrestrial planets larger than Earth (“super-Earths”). The region of multiple stable solutions is predicted to widen in parameter space for more energetic mantle convection (as would be expected for larger planets). This means that different groups can find different solutions, all potentially viable and stable, using identical models and identical system parameter values. At a more practical level, the results argue that the question of whether extrasolar terrestrial planets will have plate tectonics is unanswerable and will remain so until the temporal evolution of extrasolar planets can be constrained.
Numerical simulation of X-ray-heated winds in Seyfert galaxies. I - The case of zero angular momentum

Numerical hydrodynamics simulations are presented of X-ray heated winds believed to form the 'mirrors' which reflect light from obscured Seyfert galaxy nuclei into our line of sight. Above a likely range of parameters, it is shown that steady state flows are created when a cool torus surrounds an AGN. Some of the mass evaporated off the inner edge of the torus is captured by the central gravitational well, while the rest is driven off in a warm wind. When the central gravity is strong relative to the radiative heating rate, i.e., L/L(E) is small, nearly all the injected matter is captured. When the gravity is weaker, a given combination of heating rate and injected pressure leads to a maximum mass loss rate; when the rate at which mass is injected exceeds this amount, the excess is captured. The dividing line between these two cases comes at L/L(E) = about 0.08.
Nonlinear component of variance models

SUMMARY General aspects of nonlinearity in the context of component of variance models are discussed, and two special topics are examined in detail. Firstly, simple procedures, both formal and informal, are proposed for describing departures from normal-theory linear models. Transformation models are shown to be a special case of a more general formulation, and data on blood pressure are analyzed in illustration. Secondly, an approximate likelihood is proposed and its accurate performance is examined numerically using examples of exponential regression and the analysis of several related 2 x 2 tables. In the latter example, the approximate score test has improved power over the MantelHaenszel test.