Miracle-dz/UniFAR-FTUs huggingface dataset:
Density of the Ordinary Locus

We prove that the mod p‐reduction of a Shimura subvariety of the moduli space of abelian varieties has a Zariski dense ordinary locus for almost all height 1 primes p of the reflex field. We show further that the ordinary locus is empty at primes which are not of height 1.
Classification and stability of double water-bag plasma equilibria

The stationary states of a one-dimensional system formed by a double Water-Bag electron distribution and a fixed homogeneous ion background are discussed. Conditions for the existence of periodic and aperiodic equilibria are calculated. The stability of aperiodic solutions is investigated by a perturbative technique already used for a similar gravitational problem. A sufficient condition for stability is found to be tau 1> tau 2 ( tau 1 and tau 2 being the periods of rotation of electrons on the inner and outer contour respectively). A sufficient condition for instability, derived from a thermodynamic theory, is found to be in agreement with the results of the perturbative analysis.
Large-scale variations of the interplanetary magnetic field: Voyager 1 and 2 observations between 1-5 AU

Observations by the Voyager 1 and 2 spacecraft of the interplanetary magnetic field between 1 and 5 AU have been used to investigate the large-scale structure of the IMF in the years 1977 to 1979, a period of increasing solar activity. This complements the Pioneer 10, 11 investigation between 1 and 8.5 AU during 1972–1976 when the sun was less active. In contrast to the good agreement of the Pioneer observations with the ideal field configuration of the Parker spiral model during near solar minimum conditions, the Voyager spacecraft found notable deviations from that configuration. We attribute these deviations both to temporal variations associated with increasing solar activity, and to the effects of fluctuations of the field in the radial direction. The amplitude of the latter fluctuations was found to be large relative to the magnitude of the radial field component itself beyond approximately 3 AU. The IMF sector structure was generally not well-developed during the period of this study. Notable differences were found between Voyager 1 and 2 observations. Differences in the region 1–2 AU are attributed to the substantially different latitudes of the two spacecraft during much of the period. Later differences are most likely associated with the fact that the Voyagers moved through the region between 4 and 5 AU at different times. Both Voyager 1 and Voyager 2 observed decreases with increasing heliocentric distance in the amplitude of ‘transverse’ fluctuations in B that are consistent with the presence of predominantly undamped Alfven waves in the solar wind, although not necessarily implying the presence of them. The presence of convective structures, compressive modes, and/or a saturated instability of Alfven waves cannot be excluded by these Voyager results. Fluctuations in the strength of B (relative to mean field strength) were found to be small in amplitude, with a RMS that is approximately one third of that for the transverse fluctuations, and they are essentially independent of distance from the sun.
First Doppler images of the very young K2-dwarf PW Andromedae = HD 1405

Aims. We present the first Doppler images of the single pre-main-sequence star PW And. Its position in the HR-diagram suggests it to be in the rapid-braking phase just prior to arrival on the ZAMS. Methods. Images are obtained from seven individual spectral lines as well as from 5-nm wide chunks of spectrum that invert a total of 58 line profiles simultaneously. Results. Cool spots with temperature differences with respect to the stellar photosphere of up to 1200 K are detected. Spot occurrence is mostly within an equatorial band up to ± 40° of the stellar equator and thus contradicts magnetic-flux tube emergence models based on young K-star properties that predict an emerging latitude in two distinct bands of +45–55°. This confirms previous suggestions that current magnetic-flux tube models predict emergence latitudes too low for G-dwarfs and too high for K-dwarfs, which may be caused by the fact that the G-dwarf models heavily rely on comparisons with the Sun. We also redetermine the absolute parameters of PW And in the light of a missing Hipparcos parallax and revise its age to be more near 20 Myr, in agreement with its logarithmic lithium abundance of $2.87\pm0.05$. A precise rotational period of 1$\fd$$76159\pm0.00006$ was found from our photometric data in 2004.
PHOTOSYNTHESIS OF CARBON DIOXIDE FROM CARBON SURFACES COATED WITH OXYGEN: IMPLICATIONS FOR INTERSTELLAR MOLECULAR CLOUDS AND THE OUTER SOLAR SYSTEM

We investigate via infrared spectroscopy the synthesis of CO2 by ultraviolet irradiation (6.41 eV) of amorphous carbon covered with solid O2 at 21 K. Oxidation occurs at the O2–carbon interface promoted by photon excitation or dissociation of O2 molecules. The CO2 production is linear with photon fluence with a yield of 3.3 ± 0.3 × 10−5 CO2 photon−1; the yield does not decrease at high fluences (at least up to 2 × 1019 photons cm−2) since CO2 is not photodissociated at this photon energy. Replacing oxygen with water ice did not produce CO2 since H2O does not dissociate at this photon energy. The CO2 synthesis process discussed in this Letter does not require H2O or CO and may be important in cold astrophysical environments where O2 could be locally segregated on carbonaceous grains, such as in molecular clouds and icy objects in the outer solar system.
Higher-order differential equations and higher-order lagrangian mechanics

The study of higher-order mechanics, by various geometrical methods, in the framework of the theory of higher-order tangent bundles or jet spaces, has been undertaken by a number of authors recently: for example, Tulczyjew [16, 17], Rodrigues [14, 15] de León [8], Krupka and Musilova [11, and references therein]. In this article we wish to complement these studies by approaching the subject from a new point of view, one which we developed for second-order differential equation fields and first-order Lagrangian mechanics in [19]. In particular, our aim is to show that many of the results we obtained there may be extended to the higher-order case.
Asymptotic Behavior of Positive Solutions to Semilinear Elliptic Equations on Expanding Annuli

We study the asymptotic behavior of positive solutions of the semilinear elliptic equation Δu + ƒ(u) = 0 in Ωa, u = 0 on ∂Ωa, where Ωa = {x ∈ of RN: a < |x| < a + 1} are expanding annuli as a → ∞, and ƒ is positive and superlinear at both 0 and ∞. We first show that there are a priori bounds for some positive solutions ua(x) as a → ∞. Then, if we fix any direction, after a suitable translation of ua the limiting solutions are non-negative solutions on the infinite strip. We can obtain more detailed descriptions of these limits if ua is radially symmetric, least-energy, or least-energy with a particular symmetry.
Plasmonic metamaterials for ultrasensitive refractive index sensing at near infrared

We experimentally report a kind of plasmonic metamaterials for high sensitive refractive index sensing. The metamaterials are an X-shaped metal nanohole array fabricated by holographic lithography followed by electron-beam evaporation and lift-off procedure. Transmission spectrum measurements reveal that the localized surface plasmon resonance (LSPR) wavelength of such nanohole array shows ultrasensitive response to refractive index change in the surrounding medium. A sensitivity of 1398 nm per refractive index unit is achieved at near infrared. The high sensitivity is attributed to the well confined and greatly enhanced electric field created by LSPR as well as the increased spatial overlap between the localized electric field and the surrounding medium. The robust fabrication technique and high sensitivity provide the present plasmonic metamaterials great potentials for the development of chip-based high sensitive nanooptical biomedicine sensors and integrated devices.
The source of energy of the comet 29P/Schwassmann-Wachmann 1 outburst activity: the test of the summary

The comet 29P/Schwassmann-Wachmann 1 is an exceptional comet as far as cometary outbursts are concerned. Despite its large distance from the Sun (about 6 au), it shows quasi-regular outburst activity, usually once or twice a year. Up to now there has not been a generally accepted model that explains this phenomenon. In the first part of this paper, the most well-known hypotheses that attempt to explain the outburst activity of this comet are presented and critically analysed. The main aim of this paper is to present a model for the outburst activity of this comet. The model is based on the global analysis of the internal structure and physical and chemical processes that take place in the cometary nucleus. Numerical calculations were carried out for reasonable assumed values of a large range of cometary characteristics. The obtained results are consistent with observational data.
Baryon-baryon scattering in a one-boson-exchange-potential approach. III. A nucleon-nucleon and hyperon-nucleon analysis including contributions of a nonet of scalar mesons

The NN and YN results are presented from a one-boson-exchange-potential model. It consists of local potentials due to exchanges of members of the pseudoscalar, vector, and scalar-meson nonets. SU(3) relations are assumed for the axial-vector couplings of the pseudoscalar mesons, for the electric and magnetic couplings of the vector mesons, for the direct couplings of the scalar mesons, and for the hard-core radii. In the fit to NN the nonstrange-meson--nucleon couplings are determined. The simultaneous YN analysis determines the F/D ratios and the SU(3) parameters of the scalar-meson nonet. The description of the NN data is good (chi/sup 2//data = 2.17), and also of the . lambda.p, . sigma. /sup +/p, and . sigma. /sup -/p data up to the pion production threshold. Very close to the . sigma.N threshold we find a . lambda.N resonance, which is dominantly in the /sup 3/D/sub 1/ wave. The . lambda.p cross section is maximal just below the . sigma. /sup +/n threshold at E = 2128.918 MeV, in agreement with the experimental results of . lambda.p final-state interactions. The poles belonging to the . lambda.p resonance are located on the second Riemann sheet at E = 2131.77 +- i 2.39 MeV.
Deterministic thermostats, theories of nonequilibrium systems and parallels with the ergodic condition

Deterministic ‘thermostats’ are mathematical tools used to model nonequilibrium steady states of fluids. The resulting dynamical systems correctly represent the transport properties of these fluids and are easily simulated on modern computers. More recently, the connection between such thermostats and entropy production has been exploited in the development of nonequilibrium fluid theories. The purpose and limitations of deterministic thermostats are discussed in the context of irreversible thermodynamics and the development of theories of nonequilibrium phenomena. We draw parallels between the development of such nonequilibrium theories and the development of notions of ergodicity in equilibrium theories.
Importance of impurity diffusion for early stage degradation in AlGaN/GaN high electron mobility transistors upon electrical stress

Early stage degradation of AlGaN/GaN high electron mobility transistors (HEMTs) submitted to off- and on-state voltage bias stress was studied using UV light-assisted drain current trapping characteristics. Besides electronic traps generated underneath the gate during off-state stress, both stress conditions lead to trap generation in the transistor access region close to the drain side of the gate edge. UV light-assisted trapping analysis strongly indicates these traps to be located in the AlGaN subsurface layer of the AlGaN/GaN HEMT. Trap evolution during off-state stress performed at base plate temperatures from room temperature to 150 °C was found to exhibit an activation energy of 0.26 eV, consistent with impurity diffusion along dislocations.
Active flow control using integrated powered resonance tube actuators

This paper reports on a high frequency actuator technology development program for Active Flow Control (AFC). The innovation of using Powered Resonance Tube Bank (PRTB) actuators for the suppression of jet impingement tones is described. The actuator itself consists of a modified Hartmann resonator that is comprised of a jet aimed at the open end of a tube closed at the other end. When suitably designed and integrated, the technique produces high amplitude excitation over a range of frequencies. The resonance tube idea was then developed further into a Boeing/IIT powered resonance tube actuator bank. The actuator bank consists of an array of seven resonance tubes. Two generations of PRTBs were developed. The first (Gen.-I) was successfully applied for cavity noise suppression at DERA, UK (Stanek et al. 2000, 2001). The second (Gen.-II) actuator and its application to jet impingement noise suppression is described in this paper. The Gen.-II actuator is capable of various mass flow injection rates without changing the air pressure supplied to the actuator. Tests conducted at Boeing Saint Louis indicate that Associate Professor, Associate Fellow AIAA + Associate Technical Fellow, Associate Fellow AIAA Copyright © 2001 by the Illinois Institute of Technology and The Boeing Company the actuator was successful in suppressing both subsonic and supersonic jet impingement tones. A subsonic impinging jet (M = 0.98) was suppressed by a mass flow of 0.07 Kg/sec (1.2% of the main jet's mass flow) whereas a M = 1.09 jet required 0.13 Kg/sec (2.02% of the main jet's mass flow) for complete tonal suppression. Efforts are currently underway to minimize mass flow requirements. Our experiments give us grounds to believe that optimized PRTBs can be used for active aeroacoustic control on future aircraft.
PSR B1745–20 and Young Pulsars in Globular Clusters

Recent searches for radio pulsars in globular clusters have targeted the millisecond pulsars (MSPs) that are expected to result from the spin-up of old neutron stars in low-mass X-ray binary systems. These surveys have been very successful, discovering 34 pulsars, most of which are old and probably recycled by accretion-powered spin-up in a binary system. However, three objects have properties that are more like those of the normal population of Galactic pulsars. Timing measurements of one such pulsar, PSR B1745-20, show that it is clearly associated with the cluster NGC 6440 and that it is solitary and young, with a large magnetic field. This pulsar, together with PSR B1820-30B in NGC 6624, establishes long-period pulsars associated with globular clusters as a distinct group that seems to have a completely different genesis to the MSP population in globular clusters. Produced at a comparable rate to the MSPs, the origin of such apparently young objects in very old stellar systems is not understood.
Firing patterns and complete synchronization of coupled Hindmarsh–Rose neurons

The firing activities of Hindmarsh–Rose (HR) neurons are studied by means of numerical simulation and bifurcation analysis. A single HR neuron exhibits various firing patterns, such as quiescent state, periodic spiking, periodic bursting and chaos, when the external current input is changed. The fast/slow dynamical analysis is applied to explore the dynamical behaviour of the HR model. The complete synchronization of two coupled identical HR neurons with electrical coupling mimicking gap junctions can be realized in certain ranges of the coupling strength, whenever each individual neuron shows quiescency, periodic firing and chaos. The criteria for complete synchronization are analysed theoretically and the corresponding numerical simulation is presented as well. The persistence of the interspike intervals bifurcation structure of the coupled HR neuronal system under electrical coupling is also discussed.
Effects of transverse anisotropy on VCSEL spectra

High resolution spectral measurements on a commercial VCSEL array are reported. The authors observe frequency splittings that result from birefringence, typically 3-22 GHz, and from transverse anisotropy between differently oriented first-order modes, typically 3-17 GHz. The spectral splittings between the various transverse modes are found to be independent of polarisation.
NUCFRG2: An Evaluation of the Semiempirical Nuclear Fragmentation Database

A semiempirical abrasion-ablation model has been successful in generating a large nuclear database for the study of high charge and energy (HZE) ion beams, radiation physics, and galactic cosmic ray shielding. The cross sections that are generated are compared with measured HZE fragmentation data from various experimental groups. A research program for improvement of the database generator is also discussed.
Primitivity in Jordan Systems is Ubiquitous

Abstract The main result of the paper asserts that if a Jordan pair V = ( V + , V − ) is (σ)-primitive at some 0 ≠ b ∈ V − σ , then it is ( ± )-primitive at any 0 ≠ b ′ ∈ V ∓ . Also, if a Jordan triple system T is primitive at some 0 ≠ b ∈ T , then it is primitive at any 0 ≠ b ′ ∈ T . As a tool, similar results concerning one-sided primitivity and ∗ -primitivity of associative pairs and triple systems are established. Equivalences between our definitions of primitivity and some other appearing in the literature are also obtained as a consequence.
Triple-frequency intermittent contact atomic force microscopy characterization: Simultaneous topographical, phase, and frequency shift contrast in ambient air

We present computational simulation and experimental results of ambient air atomic force microscopy (AFM) characterization with simultaneous excitation and control of three eigenmodes of a rectangular microcantilever beam. Trimodal characterization combining amplitude and frequency modulation is an enhancement of the capabilities of the AFM technique, which could allow the rapid acquisition of topographical, phase, and frequency shift contrast with a single surface scan at normal scan rates. The results suggest that, in general, the phase and frequency shift contrast are affected similarly but in opposite directions by the tip-sample interactions, although deviations from this trend are often observed in the experiments, such that all available sources of contrast could provide complementary information on surface properties.
Interactions Between Dispersal and Dynamics: Coupled Ricker's Equations

We study a one patch model using Ricker's equation, xn+l = xner-xn, r ~ 0. We reproduce some results that Hastings ( 1993) obtained by coupling two discrete time logistic equations. Multiple attractors could occur with dispersion where there is only one attractor without dispersion. The boundary of the basins of attraction of the attractors can be fractal in nature. This makes prediction of the asymptotic behavior of most initial conditions difficult to analyze. Furthermore, we study the same model using Ricker's equation. We show that the qualitative nature of the results for a system of difference equations with dispersion depends on the form of the local dynamics.
Nanostructured diblock copolymer films with embedded magnetic nanoparticles

Nanostructured diblock copolymer films with embedded magnetic nanoparticles are prepared by solution casting. The diblock copolymer polystyrene-block-polymethylmethacrylate with a fully deuterated polystyrene block of a weight ratio of 0.22 is used as a structure-directing matrix. Maghemite nanoparticles (γ-Fe2O3) are coated with polystyrene and thus have a selective affinity to the minority block of the diblock copolymer. The hybrid film morphology is investigated as a function of nanoparticle concentration. The surface structure is probed with atomic force microscopy and scanning electron microscopy. The inner film structure and the structure at the polymer–substrate interface are detected with grazing incidence small angle neutron scattering (GISANS). Irrespective of the nanoparticle concentration a well developed micro-phase separation structure is present. From the Bragg peaks observed in the GISANS data a linear nanoparticle concentration dependence of the inter-domain spacing of the micro-phase separation structure is determined. The superparamagnetic and blocking behavior can be explained with a generalized Stoner–Wohlfarth–Néel theory which includes either an elastic torque being exerted on the nanoparticles by the field or a broad distribution of anisotropy constants.
Kinetic Theory of the Electron Gas in a Positive Background. II. Nonequilibrium Theory

A kinetic equation for the electron gas which is not subject to the usual short‐range divergence is derived. The method used is the division of the Coulomb potential into a weak part and a short‐range part. The result is expressed as the sum of a Boltzmann integral for the short range potential and a Balescu integral for the ``weak'' part, both of which are convergent. The ``dominant'' terms are identical with those obtained from the usual (divergent) Balescu equation with a cutoff in the k integration. An expression is obtained for the nondominant (i.e., nonlogarithmic) correction.
A lower limit of the cosmic mean density from the ages of clusters of galaxies

The presence of substructure in clusters of galaxies indicates that they have recently formed or accreted a significant fraction of their mass. The cosmic time at which this occurs is set in large part by the density of that region of space at very large redshift. If the distribution of density perturbations at high redshift is Gaussian, then the frequency of subclustering now is set by the mean density at recombination. Thus, the observed frequency of subclustering can be used to constrain. Surprisingly, plausible values of Lambda have little effect on this result. Unless three independent evaluations of the incidence of subclustering are all overestimates, or substructure lasts significantly longer than a crossing time in clusters, or perturbations at high redshift are not Gaussian, the universe is fairly dense (Omega sub 0 greater than about 0.5). The same line of argument suggests that direct observations (e.g., with Rosat) of evolution of the cluster population with shifts will provide a complementary direct measure of Omega sub 0.
On the Influence of Time-Varying Flow Velocity on Unsteady Aerodynamics

The effects of a periodic free-stream velocity on the unsteady aerodynamics of an airfoil in incompressible flow are examined. Existing theories are reviewed, and their simplifications and limitations are properly identified. A new general aerodynamic theory for an airfoil undergoing a combination of harmonic pitching, plunging and fore-aft motion is presented. An extension to arbitrary free-stream velocity variations and arbitrary airfoil motion is also given. The theoretical results are validated against numerical predictions made by a modern Euler code.
High-resolution calorimetric investigation of the existence of a nematic phase for the dodecylcyanobiphenyl liquid crystal

We have employed high-resolution calorimetric techniques in order to investigate the unresolved issue of the existence of a nematic phase for the liquid crystal dodecylcyanobiphenyl. Various heating and cooling runs were performed on dodecylcyanobiphenyl samples of different origin and their analysis did not reveal any signature of a nematic phase. The calorimetric results are presented in detail and they are additionally supported by optical polarising microscopy observations.