Miracle-dz/UniFAR-FTUs huggingface dataset:
Magnetocaloric properties, exchange bias, and critical behavior of Ge substituted Ni50Mn36Sn14 Heusler alloys

The effect of Ge substitution on the magnetic, magnetocaloric, and exchange bias properties of Heusler alloy system Ni50Mn36Sn14-xGex (x = 1, 2) has been investigated. With the increase of Ge content, the cell volume decreases due to the smaller Ge radius and the martensitic transition temperature increases, while the Curie temperature of the austenite phase shows a small decrease. Metamagnetic behavior is observed in the low temperature magnetization isotherms for x = 1, whereas it is less pronounced in x = 2. The maximum magnetic entropy changes associated with the martensitic transition are 7.8 J/kg K and 2.3 J/kg K for x = 1 and 2, respectively, for a field change of 5 T. Relative cooling power is found to be more in the vicinity of the Curie temperature of the austenite phase, compared to that at the martensitic transition temperature in both x = 1 and 2. At low temperatures, both the samples exhibit exchange bias effect, with x = 2 showing higher value of exchange bias field. This is ascribed to the.
Propagation in one-dimensionally stratified time-independent scattering media

We calculate the probability density distributions of the power reflection coefficient, and of the various fluxes of the components of an erstwhile plane wave that propagates in a one-dimensionally stratified slab of a time-independent scattering medium. We determine the second- and fourth-order statistics of the power-fluxes, discuss the relevance of this problem to the localization phenomenon, examine the distribution of the emerging power-flux and the limitations on the assumption that it possesses a lognormal distribution, and finally discuss and rationalize the differences between the above and the corresponding characteristics of the radiation propagating in a time-dependent variant of this problem.
Toward a transport model of collisionless magnetic reconnection

An absence of theoretical justification for the magnitude of resistivity is one of the major limitations of large-scale simulations of magnetic reconnection in collisionless magnetospheric plasma. We took advantage of the results of recent progress in kinetic modeling of collisionless dissipation in the vicinity of the magnetically neutral X point aiming to find ways to represent small-scale kinetic effects in large-scale models. The study was based on a combination of hybrid and particle methods and on analytical analysis. A comprehensive hybrid simulation code which incorporates the leading terms in electron dynamics responsible for breaking the frozen magnetic flux constraint (electron bulk flow inertia and nongyrotropic pressure effects) was utilized. The results of the comprehensive hybrid model were found to be in excellent quantitative agreement with the results of full particle simulations with similar setups. Both simulations demonstrated that the actual reconnection electric field is determined primarily by kinetic quasi-viscous effects and less by electron bulk flow inertia. An analytical expression for the quasi-viscous reconnection electric field averaged over the nongyrotropic region was obtained. Similar behavior of the evaluated quasi-viscous electric field and actual reconnection electric field taken from the simulations was demonstrated. Conventional hybrid simulations with simple nongyrotropic corrections to the electric field where also performed. The model was further reduced for utilization in MHD models. Analytical expressions for the time evolution of the reconnected flux evaluated from the MHD model modified by nongyrotropic corrections appeared to be in very good agreement with the results of comprehensive kinetic simulations. The evaluated averaged quasi-viscous electric field can be substituted into large-scale simulation models.
Optical constants of fine particles for the infrared region

Les constantes optiques n (indice de refraction) et k (coefficient d'extinction) de particules fines telles que les silicates dans le domaine IR et IR-lointain sont determinees par la methode de dispersion. La transmittance d'une boulette de KBr de particules finement broyees de mineraux tel que 2 πa/λ<<1 (α=rayon du grain et λ=longueur d'onde) a ete mesuree, et le coefficient d'absorption de masse a ete etabli independamment de la distribution de tailles des grains. La validite de la methode a ete verifiee en mesurant la reflectivite et le coefficient d'absorption de masse de l'obsidienne. Les proprietes IR du quartz fondu et des silicates hydrates sont determinees
Geometric Complexity Theory IV: Nonstandard Quantum Group for the Kronecker Problem

Introduction Basic concepts and notation Hecke algebras and canonical bases The quantum group $GL_q(V)$ Bases for $GL_q(V)$ modules Quantum Schur-Weyl duality and canonical bases Notation for $GL_q(V) \times GL_q(W)$ The nonstandard coordinate algebra $\mathscr{O}(M_q(\check{X}))$ Nonstandard determinant and minors The nonstandard quantum groups $GL_q(\check{X})$ and $\texttt{U}_q(\check{X})$ The nonstandard Hecke algebra $\check{\mathscr{H}}_r$ Nonstandard Schur-Weyl duality Nonstandard representation theory in the two-row case A canonical basis for $\check{Y}_\alpha$ A global crystal basis for two-row Kronecker coefficients Straightened NST and semistandard tableaux} A Kronecker graphical calculus and applications Explicit formulae for Kronecker coefficients Future work Appendix A. Reduction system for ${\mathscr{O}}(M_q(\check{X}))$ Appendix B. The Hopf algebra ${\mathscr{O}}_{q}^\tau$ Bibliography
Analytical geometrical responses in large deflection of simply supported piezoelectric layered plate under initial tension

Abstract The analytical geometrical responses in large deflection of a simply supported and layered piezoelectric circular plate under initial tension due to lateral pressure are presented. The approach follows von Karman plate theory for large deflection with a consideration of a symmetrically laminated case including a piezoelectric layer. The related nonlinear governing equations are derived in a non‐dimensional form and are simplified by neglecting the arising nonlinear terms, yielding a modified Bessel equation or a standard Bessel equation for the lateral slope. The associated analytical solutions are developed by imposing the simply supported edge conditions of the problem. For a 3‐layered nearly monolithic plate under a low pretension and a low applied voltage upon the piezoelectric layer, the results agree well with those obtained by using the classical plate theory for a single‐layered plate under pure mechanical loading, and thus the developed approach is validated. Typical 3‐layered piezoelectric plates are then implemented and the results show that, no apparent edge effect was found for the present problem. In additions, a piezoelectric effect appears to be present only up to a moderate initial tension. For a relatively high pretension, the tension effect tends to be dominant, resulting in nearly the same results for the geometrical responses, regardless of the magnitude of the applied voltage.
Measurable subspaces and subalgebras

a a-additive measure on S with ,u(X) = 1. Let V=. $(X, S, Iu) be the real Hilbert space of S-measurable functions f(x) with fxf2dM < 00o Forf and g in V, we write (f, g) ==fxf* gd, where (f. g) (x) -f(x) * g(x), and Ijjfj = (f, f) 1/2. Convergence in V is defined as usual in the norm topology, that is to say, limn_oO fn =f means limn_O llfn -fll =0. If f and g are functions in V such that IIf-ggl =0, they are regarded as identical and we writef =g. f _ g means that ,u I x:f(x) <g(x) } = O. For any real a, the function which is equal to a for every x is also denoted by a. A function f in V is said to be bounded if there exist a and ,B such that a <f <,B. A function on X which takes only the values 0 and 1 is called a characteristic function. For any set A CX, XA denotes the characteristic function which equals 1 on A and vanishes on X-A. If Si and S2 are subclasses of S, we write St C S2 if corresponding to each set A ES, there exists a BE S2 such that XB = XA; we write SI= S2 if S1CS2 and S2 Cs1. Let W be a subspace (- closed linear manifold) in V. W is algebraic
dc and rf performance of proton-irradiated AlGaN/GaN high electron mobility transistors

AlGaN/GaN high electron mobility transistors (HEMTs) with a range of gate lengths (0.8–1.2 μm) and widths (100–200 μm) were exposed to 40 MeV protons at fluences of 5×109 or 5×1010 cm−2. The drain–source currents in the devices decreased by 15%–20% at the higher fluence, while the extrinsic transconductance decreased by ∼30% under the same conditions. Based on the increases in the reverse breakdown voltage and the channel resistance, the main degradation mechanism is believed to be creation of deep trap states in the band gap which remove electrons from the channel. The maximum frequency of oscillation, fMAX, also decreased as a result of the proton-induced damage, with a change of −20% at the shorter gate widths and −50% at the largest widths. The reverse recovery switching time was essentially unaffected by the irradiation, remaining at ∼1.6×10−8 s. Postradiation annealing at 800 °C was successful in restoring the dc and rf performance parameters to ⩾90% of their original values. The AlGaN/GaN HEMTs are.
HISTORY OF STAR FORMATION OF EARLY TYPE GALAXIES FROM INTEGRATED LIGHT: STELLAR AGES AND ABUNDANCES

I briefly review what has been learned from determinations of mean stellar ages and abundances from integrated light studies of early-type galaxies, and discuss some new questions posed by recent data. A short discussion of spectroscopic ages is presented, but the main focus of this review is on the abundances of Fe, Mg, Ca, N, and C, obtained from comparisons of measurements taken in integrated spectra of galaxies with predictions from stellar population synthesis models.
An analytical solution of one‐dimensional consolidation for soft sensitive soil ground

An analytical solution of one‐dimensional consolidation for soft sensitive soil ground is presented. The moving boundary is introduced to indicate the notable change of consolidation behaviour of sensitive soil with the increase of stress level. It is assumed that the soil structure of the upper subsoil gradually destroys downwards with the dissipation of pore pressure, and the coefficient of consolidation as well as the coefficient of permeability of the upper subsoil become small, which hinders the dissipation of pore pressure of the lower subsoil. The consolidation degree curve obtained from the present solution is found to lie between the two curves obtained from Terzaghi one‐dimensional consolidation solution with the parameters of the undisturbed soil and the remolded soil. The calculated results provide a new explanation for a general phenomenon in the consolidation of soft sensitive soil ground, as that for high loadings the consolidation is longer than for small ones. It should be pointed out from this study that both the deep mixing method and the long vertical drains methods are effective techniques for improving deep sensitive soil ground. Copyright © 2004 John Wiley & Sons, Ltd.
On the flux and the energy spectrum of interstellar ions in the solar system

The flux density of ions created by ionization of interstellar neutral particles in the solar system and picked up by the solar wind is calculated as a function of the neutral particles. A very broad maximum occurs at an angle of 0 and a distance that depends on the density and speed of the neutral particles and on the ionization time but is typically in the general region of 10 AU. For atomic hydrogen the flux density is estimated to exceed 10/sup 4/ cm/sup -2/ s/sup -1/ over the distance range from a few to nearly 100 AU. The velocity space distribution of the interstellar ions is calculated under the assumption of no significant energy diffusion but with inclusion of adiabatic effects as well as a possible strong pitch angle diffusion. The energy spectrum is highly nonthermal and much broader than that of the solar wind ions; under the assumed conditions, interstellar protons are easily distinguishable from solar wind protons by their location in velocity space. If charge exchange is an important contributor to the ionization of hydrogen, the observed local intensity of interstellar protons should exhibit time variations correlated with the density changes of the solar wind stream structure.more » (AIP)« less
Human dynamics and stability of teleoperator systems with generalized projection-based force reflection algorithms

Abstract A new general stability result for networked bilateral teleoperator systems with projection-based force reflection is presented. Contrary to the previous results, the human operator dynamics are taken into account in the stability analysis. The human dynamics are assumed to satisfy a general condition formulated in terms of finite distance between output of the human dynamics and a certain “passivity-based” stabilizing set. In particular, this assumption allows for both passive and non-passive behaviour of the human operator. The overall stability of the bilateral teleoperator system is proven in the presence of network-induced communication constraints for an arbitrary projection-based force reflection algorithm from a broad class.
NUMERICAL METHOD FOR THE COMPUTATION OF CONJUGATE HEAT TRANSFER IN NONORTHOGONAL BOUNDARY-FITTED COORDINATES

Physical situations where heat transfer occurs between materials with differing properties are commonly encountered in engineering practice, and often the geometries of interest are irregular. A method is proposed for discretization of the conductive heal fluxes for nonorthogonal coordinates, which accounts for the possible discontinuities in the thermal conductivity in the domain. In the resulting numerical solution method, the temperature field over the entire domain can be treated in a unified manner without need for separate solutions over regions with distinct physical properties. Accuracy and consistency of the proposed discretization are assessed, and the utility of the proposed procedure is illustrated by solving conjugate heat transfer in two problems representative of those encountered in practice.
Combining forecast quantiles using quantile regression: Investigating the derived weights, estimator bias and imposing constraints

A novel proposal for combining forecast distributions is to use quantile regression to combine quantile estimates. We consider the usefulness of the resultant linear combining weights. If the quantile estimates are unbiased, then there is strong intuitive appeal for omitting the constant and constraining the weights to sum to unity in the quantile regression. However, we show that suppressing the constant renders one of the main attractive features of quantile regression invalid. We establish necessary and sufficient conditions for unbiasedness of a quantile estimate, and show that a combination with zero constant and weights that sum to unity is not necessarily unbiased.
Self‐consistent theory of time‐dependent convection in the Earth's magnetotail

A self-consistent theory of time-dependent convection in the earth's magnetotail is developed. In contrast to earlier convection models our approach takes into account that the plasma sheet particles are effectively trapped on closed geomagnetic field lines. The results demonstrate that steady state convection, although possible in principle, is unlikely to occur in the earth's magnetotail. In particular, if particle or energy losses are sufficiently small and if the outer lobe field lines have convex shape, a steady state is impossible in the framework of the present polytropic model. Quantitative models for time-dependent convection are constructed. The time dependence introduces important consequences for energy storage, stability, and spatial dependence of the convection electric field. The results are consistent with a quasi-periodic evolution of the tail, where periods of quasi-static compressional convection are followed by phases of dynamic evolution.
On the stabilization inherent in the EMS algorithm

In an attempt to overcome the EM (estimate, maximize) algorithm's lack of inherent stabilization for the solution of underdetermined linear equations, a multiplicative smoothing step was added as an essential component in the iteration, thus creating the EMS (estimate, maximize, smooth) algorithm. This paper gives an analysis of the stabilization produced through the introduction of this smoothing step. The nonlinear EMS equation are given a data smoothing only interpretation in the sense that their fixed points are solutions of a nonlinear system which takes the form of the original linear equations with only the right-hand side replaced by a nonlinear function of the fixed points. It is found that the stabilization inherent in this reformulation depends crucially on the structure of the smoothing introduced into EMS. Two types of nonuniqueness for EMS (namely the persistence of spurious solutions, associated with the underdeterminedness of the original linear system, and the artifactual presence of extraneous EM/EMS solutions, induced by the smoothing's structure) are shown to be eliminated by the use of irreducible smoothing, and thus the fate of the inherent stabilization lies with the structure of the smoothing. An exact nonnegative solution of the underlying linear system (in the case that one exists) can be obtained from the EMS algorithm if this solution is an eigenvector of the introduced smoothing matrix corresponding to the eigenvalue one. Hence, to choose the smoothing appropriately requires a priori knowledge of the desired solution.
THE NET ELECTRIFICATION OF NATURAL CLOUD DROPLETS AT THE EARTH'S SURFACE

Abstract Samples of more than 35 natural clouds were passed through a special centrifuge and an ion filter in such a way that the free electricity on the droplets and on the air could be measured separately. The net charge on typical cloud droplets is less than one ion per droplet. This shows either that cloud droplets are not appreciably charged or that both positive and negative droplets are present and the distribution is such as to make the net charge very small. The measurements show that the capture of ions of a preferred sign by cloud droplets is not important.
Publications of the Astronomical Society of the Pacific 94:960-968, December 1982 INCREASED EVIDENCE FOR OVERTONE PULSATION IN GALACTIC CEPHEIDS: SU CASSIOPEIAE

A newly determined radius value, based on a homogeneous and accurate data set and two independent methods, is used together with the currently most-reliable estimates of other physical parameters to discuss the status, and in particular the pulsation mode, of the classical cepheid SU Cas. It is argued (1) that the radius within its error limits is not compatible with currently accepted period-radius relations if fundamental-mode pulsation is assumed, (2) that the anomalously large Wesselink radius mass can only be explained if firstor second-overtone pulsation is assumed, (3) that the location of the star in the H-R diagram with respect to the Y = 0.38, Z = 0.02 fundamental-mode blue edge indicates that pulsation in the first overtone is more likely, (4) that the relative radius variation and effective temperature reveal that the star belongs to a very small group of cepheids identified by Pel and Lub (1978) which are probably overtone pulsators, and (5) that the peculiar properties of the light-curve Fourier components can probably be understood in terms of pulsation in a nonfundamental mode. The assumption that the cepheid pulsates in an excited (most probably the first overtone) mode is able to explain satisfactorily all observed properties of the star, whereas the assumption of fundamental-mode pulsation leads to difficulties which apparently cannot be resolved at the present time.
The dynamics of NAO teleconnection pattern growth and decay

This investigation performs both diagnostic analyses with NCEP/NCAR re‐analysis data and forced, barotropic model calculations to examine the dynamical mechanisms associated with the growth and decay of the North Atlantic Oscillation (NAO) teleconnection pattern. The diagnostic calculations include projection and composite analyses of each term in the stream‐function‐tendency equation.
Phenomenological modeling of shape memory alloy thermomechanical behavior

Shape memory alloys (SMAs) remarkable properties have attracted much technological interest in many research fields in the last decades. Despite of being widely used in many applications, their constitutive modeling is still in focus for many researchers due to their great variety of complex behaviors. Although many efforts towards SMAs’ thermomechanical behavior correct description has been done so far, it is common to find both simple models that are able to describe the main simple phenomena and more sophisticated models that are able to describe only a single complex phenomenon. Within this context, this article presents a one-dimensional macroscopic constitutive theory with internal constraints, which describes SMAs thermomechanical behavior, accounting for plasticity, plastic-phase transformation coupling, tension-compression asymmetry and transformation induced plasticity. Comparisons between experimental data found in the literature and numerical results provided by the model attest its capability to capture, besides the basic phenomena, more advanced features concerning SMAs’ behavior.
The -Transform Method and Delta Type Fractional Difference Operators

The Caputo-, Riemann-Liouville-, and Grunwald-Letnikov-type difference initial value problems for linear fractional-order systems are discussed. We take under our consideration the possible solutions via the classical -transform method. We stress the formula for the image of the discrete Mittag-Leffler matrix function in the -transform. We also prove forms of images in the -transform of the expressed fractional difference summation and operators. Additionally, the stability problem of the considered systems is studied.