Miracle-dz/UniFAR-FTUs huggingface dataset:
Force-Free Motion in Asymmetric Structures: A Mechanism without Diffusive Steps

A particle experiencing alternatively in time at least two potential landscapes macroscopically flat but locally asymmetric can be set into directed macroscopic motion. We show here that if the potentials have the same spatial period but extrema shifted with respect to each other in a suitable way, no diffusive step is involved in the motion generation. This model of "force-free" motion suggests the possibility of new separation techniques and completes existing paradigms for motor protein behaviour.
Solar energetic proton events and coronal mass ejections near solar minimum

The association of coronal mass ejections (CMEs) with solar energetic (9-23 MeV) proton (SEP) events are examined during the 1983-1985 approach to solar minimum. Twenty-two of 25 SEP events were associated with CMEs, a result comparable to that previously found for the period 1979-1982 around solar maximum. Peak SEP fluxes were correlated with CME speeds but not with CME angular sizes. In addition, many associated CMEs lay well out of the ecliptic plane. In a reverse study using all west hemisphere CMEs lay CMEs of speeds exceeding 800 km/s and covering the period 1979-1985, 29 of 31 events originating on the solar disk or limb were associated with observed SEPs. However, in contrast to the previous study, no cases of SEP events were found associated with magnetically well connected flares of short duration that lacked CMEs.
Quasi-minimum mean square error run-to-run controller for dynamic models

The Exponentially Weighted Moving Average (EWMA) feedback controller is a popular model-based run-to-run feedback controller that primarily uses data from previous process runs to adjust the settings of the next run. The long-term stability conditions and the transient performance of the EWMA controller have received considerable attention in the literature. Most of these studies have assumed that the process Input–Output (I-O) relationship is static and simply considered colored noise models for the process disturbance. However, process dynamics and disturbance dynamics may occur simultaneously. Under this circumstance, using EWMA-based controllers will usually lead to an unsatisfactory performance. To overcome this weakness, this article first proposes a quasi-minimum mean square error controller. The theoretical results of the long-term stability conditions are derived under a first-order transfer function model together with a general disturbance model. Furthermore, comprehensive simulation studies are conducted to compare the proposed controller with existing popular controllers. The results demonstrate that the proposed controller outperforms those popular controllers for most cases, even when the process I-O model is mis-specified or the process parameters are not precisely estimated. Supplementary materials are available for this article. Go to the publisher's online edition of IIE Transactions for the following supplemental resources: Tables 5 to 7 and Appendix.
Luminescence properties of defects in GaN

Gallium nitride (GaN) and its allied binaries InN and AIN as well as their ternary compounds have gained an unprecedented attention due to their wide-ranging applications encompassing green, blue, violet, and ultraviolet (UV) emitters and detectors (in photon ranges inaccessible by other semiconductors) and high-power amplifiers. However, even the best of the three binaries, GaN, contains many structural and point defects caused to a large extent by lattice and stacking mismatch with substrates. These defects notably affect the electrical and optical properties of the host material and can seriously degrade the performance and reliability of devices made based on these nitride semiconductors. Even though GaN broke the long-standing paradigm that high density of dislocations precludes acceptable device performance, point defects have taken the center stage as they exacerbate efforts to increase the efficiency of emitters, increase laser operation lifetime, and lead to anomalies in electronic devices. The p.
Dynamical Chaos and Decoherence

Fidelity is a convenient tool to study the sensitivity of quantum motion under Hamiltonian perturbations. In this paper we first show that classical chaos can produce the dephasing necessary to suppress quantum interference, even in the absence of any environment. To this end we consider the fidelity of mixed states, which takes into account interference amplitudes, and directly relate its decay to the decay of an appropriate classical correlation function, which is totally unrelated to quantum phases. We then discuss the dephasing in a two-qubit system, induced by the coupling to a single-particle, deterministic chaotic environment. The latter is shown to behave as a pure dephasing many-body object which induces decoherence in the system; memory effects are also taken into account.
TI K-EDGE XANES STUDIES OF TI COORDINATION AND DISORDER IN OXIDE COMPOUNDS: COMPARISON BETWEEN THEORY AND EXPERIMENT

Experimental Ti $K$-edge x-ray-absorption near-edge structure (XANES) spectra for a variety of Ti(IV)-bearing crystalline oxide model compounds are compared with those calculated using the ab initio multiple-scattering code FEFF7. A scattering-theoretic interpretation of various features in the experimental spectra, including pre-edge and main-edge peaks, is presented together with an interpretation of the effects of disorder. The observed pre-edge features are found to vary in both position (by $\ensuremath{\approx}2\ifmmode\pm\else\textpm\fi{}0.1\mathrm{eV}$) and normalized height (from $\ensuremath{\approx}0.04$ to $1.0\ifmmode\pm\else\textpm\fi{}0.05$) as a function of Ti coordination (4, 5, or 6 oxygen nearest neighbors), in agreement with calculations. In aperiodic oxide compounds where the Ti coordination is unknown (e.g., titanosilicate glasses and melts), pre-edge position and height can be used to derive reliable information on Ti coordination chemistry. For example, one can distinguish between fivefold coordinated Ti (i.e., ${\mathrm{TiO}}_{5}$) and a 50:50 mixture of fourfold- and sixfold-coordinated Ti (i.e., ${\mathrm{TiO}}_{4}$ vs ${\mathrm{TiO}}_{6}$). Finally, it is proposed that the intensity of the main-edge features can be used as a probe of disorder in the short- and medium-range environment of Ti. This is exemplified by Ti XANES studies of the effect of radiation damage on ${\mathrm{CaTiSiO}}_{5}$ and the melting of ${\mathrm{K}}_{2}{\mathrm{TiSi}}_{2}{\mathrm{O}}_{7}$ glass at high temperature.
Line fluorescence in astrophysics

A formalism to calculate emission-line strengths in the case of partial or complete overlapping of two spectral lines (so-called line fluorescence) is developed. The procedure is based on the escape probability method and is particularly suitable for use in numerical codes where line and continuum transfer is treated in this way. The method is applied to two cases of astrophysical interest: Fe II fluorescence with Ly-alpha and Ly-beta fluorescence with O I 1025 A in quasar clouds. The first of these is found to be mostly unimportant, while the second case results in an improvement over previously used methods. 14 references.
Local vibrational modes of the metastable dicarbon center(Cs–Ci)in silicon

The metastable dicarbon center $({\mathrm{C}}_{s}--{\mathrm{C}}_{i})$ in silicon has been studied by infrared absorption spectroscopy. After electron irradiation of carbon-doped silicon, new infrared absorption lines at 540.4, 543.3, 579.8, 640.6, 730.4, and $842.4 {\mathrm{cm}}^{\ensuremath{-}1}$ are observed. The lines are identified as local vibrational modes of the ${\mathrm{C}}_{s}--{\mathrm{C}}_{i}$ center in its $\mathcal{B}$ form. Illumination of the sample with band-gap light at $\ensuremath{\sim}60 \mathrm{K}$ converts the $\mathcal{B}$ to the $\mathcal{A}$ form, and local modes of the $\mathcal{A}$ form are identified at 594.6, 596.9, 722.4, 872.6, and $953 {\mathrm{cm}}^{\ensuremath{-}1}. $ The observed local mode frequencies of both forms are in excellent agreement with those calculated from ab initio theory. Our findings provide strong support for the atomic structure suggested previously for the two forms.
Designing quantum repeaters and networks

In the paper we will discuss the design of a long range quantum repeater network and the components required to realize it. We being by first reviewing the general approaches taken for distributing entanglement over long ranges and identify general limitations caused by such approaches. We present a new entanglement generation scheme that permits the near deterministic establishment of entangled links between nearest neighbor repeater nodes and can be used to construct an arbitrary topology quantum network. The creation rate is shown at worst to be a function of the maximum distance between any two adjacent quantum repeaters rather than of the entire length of the network.
Instability of standing waves for non-linear Schrödinger-type equations

Abstract A theorem is proved giving a condition under which certain standing wave solutions of non-linear Schrödinger-type equations are linearly unstable. The eigenvalue equations for the linearized operator at the standing wave can be analysed by dynamical systems methods. A positive eigenvalue is then shown to exist by means of a shooting argument in the space of Lagrangian planes. The theorem is applied to a situation arising in optical waveguides.
Evolutionary optimisation of Hénon map control: a black box approach

This paper deals with the usage of heuristics for the optimisation of the control of chaotic system. The main aim of this paper is to show a new approach of solving this problem and constructing new cost functions (CFs) operating in 'black box mode' without a previous exact mathematical analysis of the system, thus without knowledge of the stabilising target state. Three proposals of 'black box' mode CFs were tested in this paper. As a model of deterministic chaotic system, the two-dimensional Henon map was used. The optimisations were realised in several ways, each one for another desired state of system. Evolutionary algorithms (EAs) self-organising migrating algorithm and differential evolution were used. For each version, repeated simulations were conducted to outline the effectiveness and robustness of the used method and CF.
Stability Analysis of Quantized Feedback Control System

This paper studies the feedback control problem of nonlinear systems in strict-feedback form with state quantizers, which are static and bounded by sectors. Through a newly developed and versatile Lyapunov function analyzing approach for networked and quantized control systems (NQCSs). The common aim is to demonstrate that a unified study of quantization and delay effects in an uncertain system is possible by merging the quantized control law. A new delays-independent stability criterion is derived in terms of linear matrix inequality (LMI) which can be easily solved. This paper describes a system for the stability analysis of the uncertain systems subject to quantization and time-delay. Moreover, a sufficient condition for the existence of a guaranteed cost controller for NCSs is also presented by a set of LMIs. Both theoretical analysis and numerical examples show that the results in this paper are generally less conservative than those in the quadratic framework.
Er/sup 3+/-doped Al/sub 2/O/sub 3/ thin films by plasma-enhanced chemical vapor deposition (PECVD) exhibiting a 55-nm optical bandwidth

We report the first deposition of Er/sup 3+/-doped aluminum oxide thin-film optical waveguides by plasma-enhanced chemical vapor deposition (PECVD). The aluminum and erbium precursors used for the deposition of the thin films were trimethyl-aluminum and Er tri-chelate of 2,2,6,6-tetramethylheptane-3,5 dione respectively. The samples show broad, room-temperature photoluminescence at /spl lambda/=1.533 /spl mu/m. The Er/sup 3+/ concentration ranged from 0.01-0.2 at%. The full width half maximum (FWHM) of the Er/sup 3+/ emission spectrum is 55 nm, considerably broader than in silica glass. The radiative lifetime has been measured at 50-mW pump power.
A hydrodynamic approach to cosmology: the primeval baryon isocurvature model

The primeval baryon isocurvature (PBI) model for the origin of cosmological structure is explored with the aid of detailed numerical simulations. In this model we assume there is no exotic dark matter and that we live in an open universe with baryonic content initially in the range Ω 0 =0.1-0.2. The amplitude of the primeval entropy fluctuations is normalized to the COBE measurements, and the spectrum of the entropy fluctuations is taken to be a power law with index in the range m=-0.5 to 0.0. We use H 0 =80 km s -1 Mpc -1 . Shortly after decoupling in this model, a large fraction of the mass must condense to a dark collisionless component such as low-mass stars or massive black holes
A CAUTIONARY NOTE ON CONVERSION BETWEEN GALACTIC AND EQUATORIAL COORDINATE SYSTEMS.

The conversion between equatorial (α, δ) and new galactic (l, b) coordinate systems involves the straightforward application of an IAU definition and some basic spherical trigonometry. Unfortunately, the common reference books (e.g., Allen 1973; Kraus 1966) do not quote the definition correctly and frequently copied computer algorithms (e.g., Ball 1969; Manchester and Gordon 1970), having incorporated this error, lead to an inconsistent forward-backward conversion and to errors of as much as one arc minute. We present here the source of these errors and accurate parameters for use in general conversion routines.
Optical emission properties of semi‐insulating GaAs grown at low temperatures by molecular beam epitaxy

We have used cathodoluminescence (CL) and photoluminescence spectroscopy to observe deep‐level states in GaAs grown at low‐substrate temperatures by molecular beam epitaxy (LT GaAs) and the evolution of these states upon annealing. The as‐grown material shows intense deep‐level emissions which can be associated with an excess concentration of arsenic, mostly present as As‐antisite and As‐interstitial defects. These emissions subside with annealing for a few minutes at temperatures above 450 °C. CL measurements clearly show a dramatically reduced concentration of traps in the post‐growth 600 °C annealed material. Additional measurements carried out on As/GaAs systems indicate a high surface‐recombination velocity for these interfaces. These results account for a diminished role of electronic point defects in controlling the insulative behavior of LT GaAs and strongly supports a ‘‘buried’’ Schottky barrier model, which involves ultrafast recombination of carriers at surfaces of embedded arsenic clusters for.
Definition of Energy Imparted: A New Formulation Adapted to Exact Solutions of the Absorbed Dose Equation under Nonequilibrium Conditions

The volume- and time-dependent stochastic quantity the energy imparted, epsilon, defined by the International Commission on Radiation Units and Measurements, can be represented alternatively as the sum of volume- and time-independent contributions . delta.epsilon from individual basic processes. In an interaction by an ionizing particle, . delta.epsilon equals that part of the radiation energy which is converted into energy forms other than the kinetic energy of ionizing particles and rest-mass energy of nuclei and elementary particles. In a spontaneous process such as a nuclear decay, . delta.epsilon is equal to that part of the released rest-mass energy which is not converted into the kinetic energy of ionizing particles. The nonstochastic quantity the absorbed dose, D, is the mean energy imparted per unit mass of a medium. It is a volume-independent quantity and the values of . delta.epsilon for individual processes are the quantities of real significance in calculations of the absorbed dose in situations where radiaion equilibrium has not been established, e.g., in small Bragg--Gray cavities. More information about the values of . delta.epsilon for individual processes and the spectral distributions of ionizing particles is needed for the accurate treatment of cavity and interface dosimetry theories.
Microrheology of model quasi-hard-sphere dispersions

We examine if a microrheological interpretation of probe diffusion in model dispersions dominated by excluded-volume interactions and hydrodynamics captures the underlying viscoelastic relaxation mechanisms reasonably accurately. Standard dynamic light scattering is used to measure mean-squared displacements (MSDs) of visible probe particles in a refractive-index-matched model hard-sphere dispersion [poly(methyl methacrylate) particles in cycloheptyl alcohol]. The loss and storage moduli of the dispersion are extracted as functions of frequency ω from the measured MSDs. We suggest a semiempirical modification of the generalized Stokes–Einstein relation to convert the MSD to the viscoelastic modulus G*(ω). The results show a volume-fraction-dependent plateau G∞ at high frequencies in the storage modulus consistent with the domination of lubrication stresses. Viscoelasticity sets in at volume fractions φ above 0.2, and for 0.2≲φ≲0.45 the ratio of the mean viscoelastic relaxation time 〈τ〉 to the Peclet time .
Convection within an experimental wave flume

The velocity field beneath a series of progressive gravity waves was investigated using laser Doppler anemometry. The drift velocity was observed to vary with respect to both time (t) and distance (x) along the wave flume. Vorticity profiles, calculated from the velocity data, suggest that this development has its origins within the near shore region. In most cases a stable configuration is eventually achieved. A negative shear current is established in which the back flow is between 3 and 4 times larger than the predicted irrotational motion. Even in those regions which are directly adjacent to the viscous boundary layers the motion appears to depend upon the horizontal convection of vorticity, rather than its vertical diffusion. Indeed, there is a clear transition between the dominant mode of vorticity transportation. The final solution is characterised by negative near bed velocities and positive vorticity within the near surface region. This is completely opposite to that predicted by a diffusion solu.
Wurtzite InP formation during swift Xe-ion irradiation

Ion beam-induced amorphization and crystallization in InP implanted at room temperature with swift (250 and 340 MeV) ${\mathrm{Xe}}^{+}$ ions to doses of $5\ifmmode\times\else\texttimes\fi{}{10}^{13}$ and $1\ifmmode\times\else\texttimes\fi{}{10}^{14}{\mathrm{cm}}^{\mathrm{\ensuremath{-}}2},$ respectively, are investigated by transmission electron microscopy. For ion fluences above $5\ifmmode\times\else\texttimes\fi{}{10}^{13}{\mathrm{cm}}^{\mathrm{\ensuremath{-}}2},$ amorphization is registered in the near-surface region as well as around the mean ion range. The amorphous layers produced due to electronic energy deposition in the near-surface region are found to have different short-range atomic structure as compared to those produced in the depth region of nuclear energy deposition. In the case of the highest ion fluence $(1\ifmmode\times\else\texttimes\fi{}{10}^{14}{\mathrm{cm}}^{\mathrm{\ensuremath{-}}2})$ a partial crystallization of the amorphous surface layer to polycrystalline InP is observed. The process of the crystallization passes a stage of wurtzite InP phase formation.
Linear Methods in Observability and Controllability of Nonlinear Systems

Abstract The paper is devoted to the development of approach to analyze observability and controllability of nonlinear dynamic systems by linear methods. The main idea of this approach is as follows: observability (controllability) of the initial nonlinear system linear part is checked and if it is unobservable (uncontrollable), one examines whether or not the nonlinear term violates this conclusion. Sufficient conditions for unobservability and uncontrollability are obtained.
Temperature stability of ZnO:Al film properties for poly-Si thin-film devices

The crystallization of thin silicon films at temperatures between 425 and 600°C was investigated on glass substrates coated with Al-doped zinc oxide (ZnO:Al). Bare ZnO:Al layers degrade at the crystallization temperatures used. A silicon layer on top, however, efficiently prevents deterioration. The resistivity was even found to drop from 4.3×10−4Ωcm for the as deposited ZnO:Al to 2.2×10−4Ωcm in the case of aluminium induced crystallization and to 3.4×10−4Ωcm for solid phase crystallization. The temperature-stable conductivity of ZnO:Al films coated with Si opens up appealing options for the production of polycrystalline silicon thin-film solar cells with transparent front contacts.
Analysis of energy balance during collision of an air bubble with a solid wall

The dynamics of bubble-wall collision is studied by means of numerical simulations to elucidate the mechanism of bubble rebound at a solid, no-slip wall in viscous liquid. Results obtained are compared with experimental data as well as data reported in the literature. Similarities and differences are discussed. Bubble trajectory, shape deformation, added mass variation as a function of distance from the wall, and relations between various forms of energy in the system during bubble impact, liquid film formation, and rebound are presented and analyzed. On the basis of this, collision time is quantitatively defined as a time interval during which pronounced changes of kinetic energy are observed. For a rising bubble colliding with a horizontal wall, series of collisions are observed, each associated with dissipation of kinetic energy, mainly in the thin film formed between the bubble and the wall.
Ion Tail Disturbance of Comet C/Hyakutake 1996B2 Observed around the Closest Approach to the Earth

A sequential imaging observation of the ion tail of Comet C/Hyakutake 1996B2 was carried out on 1996 March 25 with a wide-field CCD imaging camera developed at the National Astronomical Observatory of Japan. We detected a peculiar knot receding along the main axis of the ion tail during our observation. This knot was located at 5.0 x 10 6 km from the nucleus on March 25.6 UT, and moved about 2.0 x 10 6 km during 5 hr. The measured velocity along the axis of the ion tail was derived to be 99.2 ±0.3 km s _1 , which is alomost constant within the observational limit. We also measured the perpendicular motion of this knot to the axis, and identified rapid acceleration. The brightness of the knot decreased during the observation. We report on preliminary results of an analysis of this phenomenon, and discuss some characteristics in this paper.
Categorical perception in absolute pitch

Three music students, possessing of absolute pitch, participated in an experiment of categorical identification of two adjacent musical pitch categories A#4 and B4. Next, they also participated in the experiment in which their ability to differenciate between two tone pulses separated by frequency level distance of 25 cents was tested. When ABX procedure was used with the tone-pulse length reduced to 20msec and the interstimulus interval extended to 10sec, the between-category discrimination in two sucjects markedly exceeded the within-category discrimination, which signalled the existence of categorical perception.