Miracle-dz/UniFAR-FTUs huggingface dataset:
Bonded projections, duality, and multipliers in spaces of analytic functions

Let q) and b be positive continuous functions on [0, 1) with T(r) -*0 as r -11 and f S 0(r) dr<xo. Denote by Ao(qp) and Ao(q)) the Banach spaces of functionsfanalytic in the open unit disc D with 1f(z)1q(z1)=o(1) and 1f(z)1p(1z1)=O(1), lzl -1, respectively. In both spaces 1IfIL,=supD Jf(z)Jp(Jz1). Let A'(1) denote the space of functions analytic in D with lffl1,, =JfJD lf(z)kb(IzI) dx dy < oc. The spaces Ao(q)), A'(b), and Ao(q)) are identified in the obvious way with closed subspaces of Co(D), L'(D), and L-(D), respectively. For a large class of weight functions q, which go to zero at least as fast as some power of (1 r) but no faster than some other power of (1 -r), we exhibit bounded projections from Co(D) onto Ao(q), from L'(D) onto A'(b), and from L'(D) onto Ao(q). Using these projections, we show that the dual of Ao(q) is topologically isomorphic to A'(/) for an appropriate, but not unique choice of 0. In addition, Ao(qp) is topologically isomorphic to the dual of A'(/). As an application of the above, the coefficient multipliers of Ao(q), A'(0), and A. (q)) are characterized. Finally, we give an example of a weight function pair q), 0 for which some of the above results fail. We study certain Banach spaces of analytic functions in the unit disc D. For example, let A,, denote the space of functions satisfying If(z)I=O((1-IzI)-1), let Ao denote the subspace with 0 replaced. by o, and let A1 denote the space of functions with ff If dx dy < oo. We may regard AO as a subspace of Co(D), the continuous functions on the disc that vanish on the boundary. We first show that there are bounded projections from Co(D) onto AO, from L1(D) onto A1, and from L'(D) onto A,, (Theorem 1). Using this, Lindenstrauss and Pelczynski have shown that A1 is topologically isomorphic to 11. Using this we show in Theorem 2 that A1 may be identified with the conjugate space of AO, and A,, with the conjugate space of A1. (For the special case indicated above this result is in Duren, Romberg, and Shields [2, Theorems 7 and 11], but our proof applies to more general weight functions, as indicated below.) Finally, we find all sequences {An} such that 2 Ana"zn E A,, whenever 2 anzn E A", and likewise for Ao and Al (Theorem 3). Presented to the Society, January 22, 1970 under the title Spaces of analytic functions with weighted supremum niorms; received by the editors July 22, 1970 and, in revised form, March 1, 1971. AMS 1970 subject classifications. Primary 46E15; Secondary 30A98.
Advantages of blue InGaN multiple-quantum well light-emitting diodes with InGaN barriers

The advantages of blue InGaN light-emitting diodes (LEDs) with InGaN barriers are studied. The L-I curves, carrier concentrations in the quantum wells, energy band diagrams, and internal quantum efficiency are investigated. The simulation results show that the InGaN/InGaN LED has better performance over its conventional InGaN/GaN counterpart due to the enhancement of electron confinement, the reduced polarization effect between the barrier and well, and the lower potential barrier height for the holes to transport in the active region. The simulation results also suggest that the efficiency droop is markedly improved when the traditional GaN barriers are replaced by InGaN barriers.
Nondipole transitions in atom excitation by ultrashort laser pulses

Interaction of a hydrogen atom with an ultrashort laser pulse is considered for the case where the pulse size in the propagation direction is of the same order or less than the characteristic size of the initially occupied state. This situation can be realized for Rydberg atoms interacting with attosecond laser pulses. The perturbation approach is used to estimate the transition amplitudes in the regime of weak excitation. For sufficiently short pulses, this regime can take place even for strong fields. It is shown that ultrashort laser pulses are able to excite nondipole transitions. The time behaviour of the transition amplitudes is studied numerically. It is found to be qualitatively different depending on whether we employ the exact vector potential or its often-used approximation based on the linear Taylor expansion over the coordinate of the propagation direction. However, to the first order of 1/c (c ≈ 137 is the speed of light in au) the amplitudes are very close for the two cases after the interaction is complete.
Low-temperature annealing of polycrystalline Si/sub 1-x/Ge/sub x/ after dopant implantation

Hall effect measurement was employed to study the isothermal annealing of boron or phosphorus implanted polycrystalline Si/sub 1-x/Ge/sub x/ thin films, with x varying from 0.3-0.55. X-ray diffraction and cross-sectional transmission electron microscopy were used to study the crystal structure, whereas X-ray photoelectron spectroscopy was used to determine the film composition and the chemical bonding states of the elements. In low-temperature (/spl les/600/spl deg/C) annealing, the conductivity, the dopant activation, and the Hall effect mobility decreased during extended annealing. The effective activation of phosphorus was less than 20% and decreased with increasing Ge content. Boron activation could reach above 70%. It was also found that Si/sub 1-x/Ge/sub x/ could be oxidized at 600/spl deg/C in a conventional furnace even with N/sub 2/ protection, especially for phosphorus doped films with high Ge content. Consequently, a low-temperature SiO/sub 2/ capping layer is necessary during extended annealing.
A solution to atmospherically induced problems in very high-accuracy alignment and levelling

Density variations in the air associated with, e.g. turbulence or quasi-stationary temperature gradients can seriously hamper high-precision optical alignment or levelling. The refraction effects due to quasi-stationary temperature gradients seem to be particularly harmful as, unlike turbulence, their influence cannot be reduced by measuring longer periods of time. In this contribution the authors describe a successful attempt to measure and correct for the atmospheric refraction effects using a so-called 'two-colour method'. It is found that not only can the quasi-static effects be compensated for, but also the effect of low-frequency turbulence is significantly reduced, even under strongly turbulent conditions (Cn2=10-13 m-23/) and for path lengths of at least one hundred, but probably several hundred, metres.
Extinction Behaviour of Contracting Bubbles in Porous Media

This paper is concerned with bubble contraction in porous media otherwise filled with viscous fluid. We suppose that an external pressure is applied to the (fixed) boundary of a porous medium, forcing a bubble to contract towards a point. By using the Baiocchi transform, we are able to give a rather complete asymptotic description of the process at times just before the bubble vanishes. The application of time-reversal to the results leads to implications for bubble nucleation.
Overpressured cocoons in extragalactic radio sources

It is shown that the cocoons of shocked gas which surround powerful double radio sources can have significantly higher pressures than the surrounding intergalactic medium. The pressures can be high enough to confine the jets in these sources, obviating the need for magnetic confinement. The cocoon pressure and the age of a radio source may be estimated from observable quantities, as demonstrated here for the radio galaxy Cygnus A. It is suggested that overpressured cocoons in high-redshift radio galaxies engulf and compress circumgalactic clouds, driving them over the Jeans limit and triggering star formation. It is proposed that this process leads to the observed alignments of optical continuum emission with radio source axes. 28 refs.
InGaAs quantum wire intermediate band solar cell

Intermediate band solar cells were realized using a GaAs (311)A p-i-n junction with Si as both the p- and n-type dopant, where the intermediate band was realized with a stack of InGaAs quantum wires. This quantum wire photovoltaic device demonstrates a non-trivial increase in solar cell efficiency over a reference p-i-n GaAs (311)A junction resulting from a significant increase in short circuit current and an only slight decrease in open circuit voltage. Presented are optical and electrical characterizations of these devices.
High current and directional electron beams produced from gold photocathodes by ultrashort excimer laser pulses

The surface photoelectric effect induced by 500 fs excimer laser pulses in a gold metallic target has been studied. Unexpectedly high current densities of 4 kA/cm2, induced by laser intensities in the 3 GW/cm2 range have been measured. Intense photoelectron emission could also be observed at laser intensities up to 10 GW/cm2 without plasma formation. Furthermore, an electron angular distribution of 18°±2° was obtained for laser intensities in the range of 1–3 GW/cm2. These results are compared to those obtained in previous work for single‐photon and multiphoton photoeffects by using longer laser pulses, and their potential exploitation for free‐electron laser and accelerator applications is discussed.
Recent results from experimental studies on laser–plasma coupling in a shock ignition relevant regime

Shock ignition (SI) is an appealing approach in the inertial confinement scenario for the ignition and burn of a pre-compressed fusion pellet. In this scheme, a strong converging shock is launched by laser irradiation at an intensity Iλ2 > 1015 W cm−2 µm2 at the end of the compression phase. In this intensity regime, laser–plasma interactions are characterized by the onset of a variety of instabilities, including stimulated Raman scattering, Brillouin scattering and the two plasmon decay, accompanied by the generation of a population of fast electrons. The effect of the fast electrons on the efficiency of the shock wave production is investigated in a series of dedicated experiments at the Prague Asterix Laser Facility (PALS). We study the laser–plasma coupling in a SI relevant regime in a planar geometry by creating an extended preformed plasma with a laser beam at ∼7 × 1013 W cm−2 (250 ps, 1315 nm). A strong shock is launched by irradiation with a second laser beam at intensities in the range 1015–1016 W cm−2 (250 ps, 438 nm) at various delays with respect to the first beam. The pre-plasma is characterized using x-ray spectroscopy, ion diagnostics and interferometry. Spectroscopy and calorimetry of the backscattered radiation is performed in the spectral range 250–850 nm, including (3/2)ω, ω and ω/2 emission. The fast electron production is characterized through spectroscopy and imaging of the Kα emission. Information on the shock pressure is obtained using shock breakout chronometry and measurements of the craters produced by the shock in a massive target. Preliminary results show that the backscattered energy is in the range 3–15%, mainly due to backscattered light at the laser wavelength (438 nm), which increases with increasing the delay between the two laser beams. The values of the peak shock pressures inferred from the shock breakout times are lower than expected from 2D numerical simulations. The same simulations reveal that the 2D effects play a major role in these experiments, with the laser spot size comparable with the distance between critical and ablation layers.
Finite-Difference Simulation of Elastic Wave with Separation in Pure P- and S-Modes

Elastic wave equation simulation offers a way to study the wave propagation when creating seismic data. We implement an equivalent dual elastic wave separation equation to simulate the velocity, pressure, divergence, and curl fields in pure P- and S-modes, and apply it in full elastic wave numerical simulation. We give the complete derivations of explicit high-order staggered-grid finite-difference operators, stability condition, dispersion relation, and perfectly matched layer (PML) absorbing boundary condition, and present the resulting discretized formulas for the proposed elastic wave equation. The final numerical results of pure P- and S-modes are completely separated. Storage and computing time requirements are strongly reduced compared to the previous works. Numerical testing is used further to demonstrate the performance of the presented method.
Categorical compactness for rings

Abstract In this paper we study categorical compactness with respect to a class of objects F being motiveated by examples arising from modules, abelian groups, and various classes of non-abelian groups. This theory is then applied to the category of not necessarily associative rings. In particular, we study the example arising from the class of all torsion-free rings. This work extends some recent results of B. J. Gardner for associative rings and radical classes.
A memory which forgets

The model of Hopfield for a neural network with associative memory is modified by the introduction of a maximum value for the synaptic strength; in this way old patterns are automatically forgotten and the memory recalls only the most recent ones. If the parameters are correctly chosen, the memory never goes into the state of total confusion, characteristic of the Hopfield model.
The role of structural properties on deep defect states in Cu2ZnSnS4 studied by photoluminescence spectroscopy

In this study, we investigated the photoluminescence (PL) properties of Cu2ZnSnS4 polycrystals. Two PL bands at 1.27 eV and 1.35 eV at T = 10 K were detected. Similar behaviour with temperature and excitation power was found for both PL bands and attributed to the band-to-impurity recombination. Interestingly, the thermal activation energies determined from the temperature dependence of the PL bands coincide. With the support of the Raman results, we propose that the observed PL bands arise from the band-to-impurity-recombination process involving the same deep acceptor defect with ionization energy of around 280 meV but different Cu2ZnSnS4 phase with different bandgap energy.
Highly selective and low damage atomic layer etching of InP/InAlAs heterostructures for high electron mobility transistor fabrication

Highly selective, low damage atomic layer etching (ALET) technology was developed for dry gate recess during the fabrication of InGaAs∕InP∕InAlAs high electron mobility transistors lattice matched to InP substrates. Etching characteristics of InP layer on top of InAlAs layer and the surface chemistry of the exposed InAlAs layer were investigated by utilizing angular resolved x-ray photoelectron spectroscopy. Finally, InAlAs Schottky diodes were fabricated by utilizing chlorine-based ALET technology and conventional Ar-based dry recess and their electrical characteristics were compared. By using the ALET, the etch selectivity as high as 70:1 was achieved for InP over InAlAs heterostructures and the stoichiometric modification of InAlAs was observed to be negligible after the recess etch process. Schottky diodes fabricated after the ALET exhibited the lower ideality factor and the higher Schottky barrier height compared to those fabricated with Ar-based plasma etching.
Simultaneous Stabilization of Three or More Plants: Conditions on the Positive Real Axis Do Not Suffice

The problem of the simultaneous stabilizability of a finite family of single-input, single-output time-invariant systems by a time- invariant controller is studied. The link between stabilization and avoidance is shown and is used to derive necessary conditions for the simultaneous stabilization of k plants. These necessary conditions are proved to be, in general, not sufficient. This result also disproves a long- standing conjecture on the stabilizability condition of a single plant with a stable minimum phase controller. The main result is to show that, unlike the case of two plants, the existence of a simultaneous stabilizing controller for more than two plants is not guaranteed by the existence of a controller such that the closed loops have no real unstable poles.
16-component theory of the spin-1 particle and its generalization to arbitrary spin

The criteria of validity of this theory are, among others, the nonrelativistic approximation, the classical approximation which gives the Thomas spin theory, and the values of the energy in a homogeneous magnetic field. In the tensorial form, this theory is more complicated than the 10-component Proca theory, but, in the matrix form, it is more convenient than the preceding theory using the Petiau-Duffin-Kemmer matrices, because only matrices obeying the Dirac conditions intervene. When the mass term is equal to zero ($k=0$) one can recover the Maxwell equations, as a particular case. Finally, the theory may be easily generalized for an arbitrary spin of value $J=\frac{n}{2}$.
Optimal Control of the Blowup Time

The problem of optimal control of the blowup time of a system of nonlinear controlled ordinary differential equations is considered in this paper. The blowup time is defined to be the first time that the norm of the trajectory becomes infinite. When one seeks to maximize the blowup time the pair $(V(x),\Omega)$ comes under consideration, where $x \in R^n \mapsto V(x) \in [0,\infty]$ is the value function and $\Omega \subset R^n$ is the blowup set. This is the set of initial points from which finite time blowup will occur for any control. We prove that $(V,\Omega)$ is the unique viscosity solution of the equation $1+\max_{z}D_xV(x)\. f(x,z)=0, x \in \Omega$ and conditions $\lim_{|x| \to \infty}V(x)=0, \lim_{x \to \partial \Omega}V(x) = +\infty. $ Finally, we derive the Pontryagin maximum principle for an optimal control. Some generalizations are also discussed.
A weighting function model of transient turbulent pipe friction

A weighting function model of transient turbulent pipe friction at moderate Reynolds Numbers is developed in a similar manner to Zielke's equivalent expression for laminar flow (1968). It is shown that a family of weighting function curves exists and that Zielke's curve is an upper bound asymptote that is valid for low Reynolds numbers, not only for laminar flow. The new weighting function model is based on an approximate representation of a turbulent pipe flow as a laminar annulus surrounding a uniform core. The acceptability of this representation is demonstrated by comparing wall shear-stress histories predicted using this model with equivalent histories predicted using a five-region eddy viscosity model. It is shown that the new weighting function curves can be represented with sufficient accuracy by exponential relationships similar to those proposed by Trikha for transient laminar flows (1975).
Bandwidth Enhancement of Dielectric Resonator Reflectarray Antenna

Abstract Aperture-coupled dielectric resonator antenna is proposed using a novel reflectarray antenna unit cell structure. It is shown that a bowtie-shaped slot can enhance the bandwidth performance of a reflectarray antenna. The unit cell's reflection phase response was verfified experimentally using the waveguide simulator method. An array comprising of 256 elements was simulated using the finite integration technique based on the proposed unit cell. The array exhibits a 3-dB gain bandwidth of 28% and radiation efficiency of 43.8%. These results were validated using the transmission-line method.
Elastic Moduli of Single-Crystal Zinc Oxide

New interest in zinc oxide has developed since it has been discovered to be piezoelectric. In line with this interest the zero field adiabatic elastic moduli have been measured. A high frequency, 60 to 500 Mc ultrasonic pulse technique was employed. Two crystals with sufficiently high conductivity to effectively short the electric field were available for the measurements.A density of 5.676 g/cm3 was used to calculate the zero-field adiabatic elastic moduli. This density was taken as exact with reference to the error limits.The moduli in units of 1012 dyn/cm2 at 25°C are: c11E = 2.097 ±0.1%, c12E = 1.211 ±0.15%, c13E = 1.051 ±0.15%, c33E = 2.109 ±0.1%, c44E = 0.4247 ±0.1%, c66E = 12(c11E−c12E) = 0.4429±0.1%.
Variable selection for the single‐index model

We consider variable selection in the single-index model. We prove that the popular leave-m-out crossvalidation method has different behaviour in the single-index model from that in linear regression models or nonparametric regression models. A new consistent variable selection method, called separated crossvalidation, is proposed. Further analysis suggests that the method has better finite-sample performance and is computationally easier than leave-m-out crossvalidation. Separated crossvalidation, applied to the Swiss banknotes data and the ozone concentration data, leads to single-index models with selected variables that have better prediction capability than models based on all the covariates. Copyright 2007, Oxford University Press.
Numerical simulation of ion cyclotron waves in tokamak plasmas

Introduction. The code TORIC [1] solves Maxwell equations in the Ion Cyclotron (IC) range of frequencies in toroidal axisymmetric plasmas. To make possible selfconsistent simulations of IC experiments in tokamaks, TORIC has been coupled with SSFPQL [2], which solves the quasilinear Fokker-Planck (QLFP) equation for ions. The TORIC-SSFPQL package has been described in some details in [3]. Here we will briefly recall the physics included in the codes, and discuss some features of the model related to specifically toroidal effects. Use of this package for parametric studies of IC heating scenarios in ASDEX Upgrade is illustrated in a companion contribution to this Conference [4]. TORIC. The model implemented in TORIC includes propagation and damping of the externally excited fast wave (FW), and of Ion Bernstein (IBW) and Ion Cyclotron (ICW) waves which can be excited by linear mode conversion (LMC) near ion-ion resonances. The absorption channels are fundamental and first harmonic IC heating of ions, and Landau and Transit Time damping by electrons. Optionally, damping of the FW at higher IC harmonics can be simulated, although not simultaneously with mode conversion [5]. The wave equations are derived from Vlasov equation by expanding the e.m. fields in Fourier modes in the toroidal and poloidal angles [6]. While for the FW an expansion to second order in the Larmor radius is adequate, large Larmor radius effects are taken into account to describe IBWs [7], in such a way that the local dispersion relation of the wave equations solved by TORIC is everywhere a good approximation of the full hot-plasma dispersion relation. As a stand-alone, TORIC assumes local thermal equilibrium; for iteration with SSFPQL the coefficients of the wave equations are evaluated (to all orders in the Larmor radius) using the distributions predicted by the quasilinear kinetic equation as explained in [3]. The spectral representation of the hf field allows a rigorous definition of the local wavevec
Unique f-level resonant state within the gap in Ce3Au3Sb4 single crystals: Magnetic, thermal, and transport properties

The magnetic, thermal, and transport properties of single crystals of the narrow gap semiconductor Ce3Au3Sb4 have been studied. Transport data are consistent with an exponential activation and variable range hopping at low temperatures, which is characteristic of weak disorder and localization. The specific heat and the magnetic susceptibility data suggest the existence of a large density of states of localized states in the gap. The physics is then different from standard Kondo insulators. From its unique physical properties, we propose a three band model valence, conduction, and f bands with weak disorder that explains most of the experimental findings.