Miracle-dz/UniFAR-FTUs huggingface dataset:
One-step implementation of a multiqubit controlled-phase gate with superconducting quantum interference devices coupled to a resonator

A scheme for one-step implementation of an n-qubit controlled-phase gate is proposed in a superconducting quantum interference device (SQUID) system. The distinguishing feature of this scheme is the simultaneous and nonidentical off-resonant Raman coupling of the n SQUID qubits to a single-mode resonator and the microwave pulses. The scheme is efficient and simple because it requires only one-step evolution, and no adjustments of the experimental parameters are needed during the operation.
An exact branch‐and‐bound procedure for the quadratic‐assignment problem

The quadratic-assignment problem is a difficult combinatorial problem which still remains unsolved. In this study, an exact branch-and-bound procedure, which is able to produce optimal solutions for problems with twelve facilities or less, is developed. The method incorporates the concept of stepped fathoming to reduce the effort expended in searching the decision trees. Computational experience with the procedure is presented.
Wind Speed Control of Tropical Orographic Convection

AbstractThis study compares observations from the Dominica Experiment (DOMEX) field campaign with 3D and 2D Weather Research and Forecasting Model (WRF) simulations to understand how ambient upstream wind speed controls the transition from thermally to mechanically forced moist orographic convection. The environment is a conditionally unstable, tropical atmosphere with shallow trade wind cumulus clouds. Three flow indices are defined to quantify the convective transition: horizontal divergence aloft, cloud location, and island surface temperature. As wind speed increases, horizontal airflow divergence from plume detrainment above the mountain changes to convergence associated with plunging flow, convective clouds relocate from the leeward to the windward side of the mountain as mechanically triggered convection takes over, and the daytime mountaintop temperature decreases because of increased ventilation and cloud shading. Possible mechanisms by which wind speed controls island precipitation are also disc.
Delay and data packet dropout separately related stability and state feedback stabilisation of networked control systems

There exist bounded transmission delay and data packet dropout in the networked control systems (NCSs). When the sensors and actuators are time-driven and controllers are event-driven, the NCSs can be modelled as a class of discrete-time systems with time-varying input delay. Most of similar articles simply combine delay and packet dropout to analyse and synthesise NCSs without distinguishing their different impacts, which leads to conservative results. In this study, the authors summarise that the number of consecutive data packet dropout increases gradually in case of packet dropout. A novel Lyapunov-Krasovskii functional is constructed based on this increment property, so less conservative results are obtained through the Lyapunov-Krasovskii functional approach. In addition, the upper bound of a Lyapunov functional difference cross term is reasonably estimated to further reduce the conservativeness. Stability and stabilisation criteria which are separately related to the transmission delay and data packet dropout are presented. The obtained conditions are based on linear matrix inequalities, which can be solved easily by MATLAB or other numerical software.
Effect of orthorhombic distortion on dielectric and piezoelectric properties of CaBi4Ti4O15 ceramics

High temperature bismuth layered piezoelectric and ferroelectric ceramics of CaBi4Ti4O15 (CBT) have been prepared using the solid state route. The formation of single phase material with orthorhombic structure was verified from x-ray diffraction and Raman spectroscopy. The orthorhombic distortion present in the CBT ceramic sintered at 1200 °C was found to be maximum. A sharp phase transition from ferroelectric to paraelectric was observed in the temperature dependent dielectric studies of all CBT ceramics. The Curie’s temperature (Tc=790 °C) was found to be independent of measured frequency. The behavior of ac conductivity as a function of frequency (100 Hz–1 MHz) at low temperatures (<500 °C) follows the power law and is attributed to hopping conduction. The presence of large orthorhombic distortion in the CBT ceramic sintered at 1200 °C results in high dielectric constant, low dielectric loss, and high piezoelectric coefficient (d33). The observed results indicate the important role of orthorhombic dist.
Ultraviolet observations of starburst and mini-Seyfert galactic nuclei

The high excitation emission line galaxies NGC 1667, NGC 5135, and IC 5135 show activity which, while similar to that of Seyfert 2 galaxies, is 1-2 orders of magnitude smaller. The line and continuum emission is in all three cases more extended than would correspond to a point source. In addition to showing such Seyfert-like characteristics as broad, low contrast wings in the Lyman-alpha profiles and unusual strengths in the emission lines of such high ionization species as He II, NGC 5135 and IC 5135 show starburst characteristics in their UV spectra, with P Cygni profiles that furnish direct evidence of the presence of very massive and hot O stars in their nuclei. It is suggested that they may be galaxies undergoing the transition from the starburst stage to the mini-Seyfert stage.
Phonon contribution to friction stress in an atomically flat contact of crystalline solids at low temperature

It has recently been shown both experimentally and theoretically that there is no static friction in a contact of atomically flat crystalline solids provided the periods of their lattices are incommensurate and their interaction does not exceed some critical value. In dielectric materials, the only mechanism of friction in this case is generation of phonons. In the present paper, it is shown that, at low temperatures, the phonon contribution to the friction force can be very small by virtue of the quantum mechanical nature of the elementary excitations in a solid. Incommensurate dielectric crystals could therefore slip at low temperatures practically without friction.
Solving inhomogeneous inverse problems by topological derivative methods

We introduce new iterative schemes to reconstruct scatterers buried in a medium and their physical properties. The inverse scattering problem is reformulated as a constrained optimization problem involving transmission boundary value problems in heterogeneous media. Our first step consists in developing a reconstruction scheme assuming that the properties of the objects are known. In a second step, we combine iterations to reconstruct the objects with iterations to recover the material parameters. This hybrid method provides reasonable guesses of the parameter values and the number of scatterers, their location and size. Our schemes to reconstruct objects knowing their nature rely on an extended notion of topological derivative. Explicit expressions for the topological derivatives of the corresponding shape functionals are computed in general exterior domains. Small objects, shapes with cavities and poorly illuminated obstacles are easily recovered. To improve the predictions of the parameters in the successive guesses of the domains we use a gradient method.
Surface fitting with scattered noisy data on Euclidean D-space and on the sphere

An overview of cross validated spline methods for smoothing noisy data in the plane, in Euclidean espace, and on the sphere is given. Cross-validated thin plate smoothing splines are reviewed and an efficient numerical algorithm for computing them for problems with up to several hundred data points is described. Some numerical results for a two-dimensional example are given. A theory of vector splines for smoothing noisy vector data on the sphere is given. The use of generalized cross-validation to estimate both the smoothing parameter as well as the relative energy to be assigned to the divergent and nondivergent part of the smoothed vector field is described and tested numerically on simulated upper air horizontal wind fields.
The evolution of large-scale structure in a universe dominated by cold dark matter

The results of numerical simulations of nonlinear gravitational clustering in universes dominated by weakly interacting, 'cold' dark matter are presented. The numerical methods used and the way in which initial conditions were generated are described, and the simulations performed are catalogued. The evolution of the fundamental statistical properties of the models is described and their comparability with observation is discussed. Graphical comparisons of these open models with the observed galaxy distribution in a large redshift survey are made. It is concluded that a model with a cosmological density parameter omega equal to one is quite unacceptable if galaxies trace the mass distribution, and that models with omega of roughly two, while better, still do not provide a fully acceptable match with observation. Finally, a situation in which galaxy formation is suppressed except in sufficiently dense regions is modelled which leads to models which can agree with observation quite well even for omega equal to one.
Range of validity of McCumber theory in relating absorption and emission cross sections

The relation between absorption and emission spectra in a rare-earth doped solid is explored analytically and through numerical simulations on a model system. It is found that the widely used theory of McCumber [D. E. McCumber, Phys. Rev. 136, A954 (1964)] is strictly valid only when the linewidth of each individual transition between Stark levels is ≪kBT. When this assumption is relaxed, deviations between actual simulated spectra and McCumber-calculated spectra are found for both homogeneous and inhomogeneous broadening. The McCumber transform introduces a characteristic distortion of each component transition, in which the low-energy side of the spectrum is increased, and the high-energy side is decreased. The average degree of distortion for the model system is calculated to be 5% for a homogeneous width of 50 cm−1 at room temperature, but only 1% for a purely inhomogeneous width of 50 cm−1. For both homogeneous and inhomogeneous spectra, the distortion varies with the linewidth Δν as (Δν)3/2. The dep.
Error analysis and design of the Nutt time-interval digitiser with picosecond resolution

Several sources of errors related to the Nutt time-interval digitiser are discussed, including the quantisation process, time jitter, non-linearity of time stretchers and phase noise of the reference clock. A model of the total measurement uncertainty is formulated. The authors also describe the main circuitry and test results of a microprocessor-controlled digitiser which has been developed to achieve a negligible quantisation error (1 ps resolution) and 1 ms range.
Gravitational radiation from nonspherical infall into black holes

We perform strong-field perturbation calculations of the gravitational radiation emitted when spheroidal dust shells of mass m and arbitrary eccentricity fall radially into Schwarzschild black holes of mass M>>m. We derive analytically the scaling laws obeyed by our numerical results in limiting eccentricity regimes. We demonstrate that the total energy emitted in gravitational radiation by a nonspherical dust cloud falling into a black hole is always less than the energy radiated by a point particle of the same mass falling into the hole. The suppression results from interference between waves emitted from different regions of the extended, infalling mass.
Pressure and Flow Characteristics in a Rotating Two-Pass Square Duct With 45-Deg Angled Ribs

Measurements are presented of the local velocity and wall static-pressure distributions by using laser-Doppler velocimeter and pressure transducers, respectively, in a rotating two-pass square duct with ribs placed on the leading and trailing walls at an angle of 45 deg to the main stream. The ribs were square in cross section and in a parallel mode of arrangement. The rib-height/duct-height ratio and the pitch/rib-height ratio were 0.136 and 10, respectively. The duct Reynolds number was 1 × 10 4 and rotation number Ro ranged from 0 to 0.2. Results are addressed in terms of the evolutions of both main flow and cross-stream secondary flow, the distributions of the pressure coefficient, and the variation of friction factor with Ro. In addition, the relationships between the regional averaged Nusselt number, transverse and convective mean velocity component, and turbulent kinetic energy are documented. Simple expressions are obtained to correlate friction factor with Ro, which are lacking in the published literature for ducts ribbed with 45-deg ribs. The 45-deg ribs are found to reduce the friction loss to 60% of the 90-deg ribs for rotating duct under the same operating conditions. For CFD reference, the fully developed flow condition is absent for the rotating ribbed duct investigated. The measured evolution of complex secondary flow vortices is believed to be a challenge to numerical simulations.
Turbulent Transient Gas Injections

Compressible transient turbulent gaseous jets are formed when natural gas is injected directly into a diesel engine. Multi-dimensional simulations are used to analyze the penetration, mixing, and combustion of such gaseous fuel jets. The capability of multi-dimensional numerical simulations, based on the k-e turbulence model, to reproduce the experimentally verified penetration rate of free transient jets is evaluated. The model is found to reproduce the penetration rate dependencies on momentum, time, and density, but is more accurate when one of the k-e coefficients is modified. The paper discusses other factors affecting the accuracy of the calculations, in particular, the mesh density and underexpanded injection conditions. Simulations are then used to determine the impact of chamber turbulence, injection duration, and wall contact on transient jet penetration. The model also shows that gaseous jets and evaporating diesel sprays with small droplet size mix at much the same rate when injected with equivalent momentum injection rate.
Ca II H and K measurements made at Mount Wilson Observatory, 1966-1983

Summaries are presented of the photoelectric measurements of stellar Ca II H and K line intensity made at Mount Wilson Observatory during the years 1966-1983. These results are derived from 65,263 individual observations of 1296 stars. For each star, for each observing season, the maximum, minimum, mean, and variation of the instrumental H and K index 'S' are given, as well as a measurement of the accuracy of observation. A total of 3110 seasonal summaries are reported. Factors which affect the ability to detect stellar activity variations and accurately measure their amplitudes, such as the accuracy of the H and K measurements and scattered light contamination, are discussed. Relations are given which facilitate intercomparison of 'S' values with residual intensities derived from ordinary spectrophotometry, and for converting measurements to absolute fluxes. 28 refs.
A compact, inexpensive infrared laser system for continuous-wave optical stimulation of the rat prostate cavernous nerves

Optical nerve stimulation (ONS) has been commonly performed in the laboratory using high-power, pulsed, infrared (IR) lasers including Holmium:YAG, diode, and Thulium fiber lasers. However, the relatively high cost of these lasers in comparison with conventional electrical nerve stimulation (ENS) equipment may represent a significant barrier to widespread adoption of ONS. Optical stimulation of the prostate cavernous nerves (CN’s) has recently been reported using lower cost, continuous-wave (CW), all-fiber-based diode lasers. This preliminary study describes further miniaturization and cost reduction of the ONS system in the form of a compact, lightweight, cordless, and inexpensive IR laser. A 140-mW, 1560-nm diode laser was integrated with a green aiming beam and delivery optics into a compact ONS system. Surface and subsurface ONS was performed in a total of 5 rats, in vivo, with measurement of an intracavernous pressure (ICP) response during CW laser irradiation for 30 s with a spot diameter of 0.7 mm. Short-term, CW ONS of the prostate CN’s is feasible using a compact, inexpensive, batterypowered IR laser diode system. This ONS system may represent an alternative to ENS for laboratory studies, and with further development, a handheld option for ONS in the clinic to identify and preserve the CN’s during prostate cancer surgery.
Numerical Simulation of Thermocapillary Drop Motion with Internal Circulation

The thermocapillary motion of drops in zero gravity is analyzed numerically. When convective transport is important, the internal circulation in the drop has a profound effect on the temperature distribution in its vicinity and hence on its migration speed. For sufficiently large values of the Marangoni number Ma, for steady motion of the drop, the temperature difference on the drop surface and its scaled speed increase with Ma. This is in contrast to (1) existing computational results for liquid drops whose scaled speed decreases with Ma and (2) asymptotic results for gas bubbles whose scaled speed is independent of Ma when it is large.
Hot molecular cores

The scope of this contribution is to review and discuss recent findings concerning the molecular environment of high-mass star forming regions. Special attention is devoted to “hot molecular cores” and their role in the formation of massive stars. After analysing the relationship between such cores and the surrounding molecular clumps, we discuss the results of interferometric observations of these objects and propose an evolutionary sequence proceeding from cold, pre-stellar cores to ultracompact HII regions.
Global Branch of Solutions for Non‐Linear Schrödinger Equations with Deepening Potential Well

We consider the stationary non‐linear Schrödinger equation Δu+{ 1+λg(x) }u=f(u)with u∈H1RN,u ≠0 where λ > 0 and the functions f and g are such that lims→0f(s)s=0and1
Quantitative and comparative characterizations of plasma process-induced damage in advanced metal-oxide-semiconductor devices

Two plasma process-induced damage mechanisms are investigated in detail: charging damage by plasma conduction current through two different gate dielectrics (SiO2 and HfAlOx/SiO2 (high-k)) in metal-oxide semiconductor (MOS) devices and ion-bombardment damage in Si surfaces. The charging damage was identified as the changes in tunnelling currents and the decrease in the reliability lifetime. The behaviours were found to depend on the dielectric thickness as well as dielectric materials (SiO2 and high-k). For p-ch MOS transistors, the threshold voltage of devices with high-k exposed to Ar-based plasma shifted towards the positive direction, while with SiO2, towards the negative direction. This may be attributed to the difference in the trap site generation process and trapping phenomenon. With regard to the ion-bombardment damage, the changes in optical structures (surface layer thicknesses, dielectric function and mechanical strain within the interfacial damaged layers) by direct current and electron cyclotron resonance plasma exposures were investigated by spectroscopic ellipsometry and photoreflectance spectroscopy. The plasma-induced stressing current and the defect density were estimated to quantify the damage. The experimental findings provide key implications that a plasma-induced damage is one of the limiting factors for future-scaled device designs.
Fine-structure population ratios for the 3P ground state of C I

Results of recent R-matrix calculations of electron impact excitation rates for the 2s2 2p2 3Pj-2s2 2p2 3Pj, fine-structure transition in C I are used to derive density sensitive population ratios n(3P1)/n(3Po) and n(3P2)/n(3Po) for a range of temperatures and electron and neutral hydrogen densities. The present data differ appreciably from those of Smeding and Pottasch (1979) and illustrate the importance of adopting accurate electron excitation rates in population ratio calculations, even in the case of neutrals. 24 refs.
A mixed-strategy minimax theorem without compactness

Minimax theorems for infinite games generally require that both players choose their pure strategies from compact sets and have semicontinuity requirements in both variables. This paper proves the following theorem. Let X be a compact Hausdorfl space and let $(Y,A)$ be a measurable space. Let $f:X \times Y$ be a measurable function which is bounded below and lower semicontinuous on X for all fixed y in Y. Let M be any convex set of probability measures (mixed strategies) on $(Y,A)$. Then \[\mathop {\min }\limits_{\mu \in B(X)} \mathop {\sup }\limits_{\rho \in M} \iint {f(x,y)d\mu d\rho} = \mathop {\sup }\limits_{\rho \in M} \mathop {\min }\limits_{\mu \in B(X)} \iint {f(x,y)d\mu d\rho},\] where $B(X)$ denotes the regular Borel probability measures on X.
Units in modular group rings

Let G be a finite p-group and let U(G) denote the group of normalized units in the modular group ring of G. If G is nonabelian, then it is shown that the nonregular group Zp ^ Zp is involved in U(G). Here Zp is the group with p elements and Zp I Zp is wreath product. Let F[G] denote the group ring of a finite p-group G over the prime field F—GFip). We define the group of normalized units in F[G] by UiG) ={Z^G F[G] 2Z ax = 1 \ . We see easily that | UiG) | = p\°l~1 and that UiG) is in fact a normal Sylow p-subgroup of the full group of units in P[G]. If G is abelian, then UiG) is abelian and its structure is therefore basically simple. On the other hand if G is nonabelian then the structure of UiG) becomes immediately very complicated. As an indication of this fact we offer the following results. Theorem. // G is nonabelian, then ZP \ Zp is involved in UiG). Corollary. If G is nonabelian, then UiG) is not regular. The corollary follows immediately from the theorem since regularity is inherited by subgroups and quotient groups and since Zv \ Zp is known to be nonregular. We remark that the corollary is trivial for p = 2 since a 2-group is regular if and only if it is abelian. On the other hand the proof of the theorem for p = 2 requires the consideration of several special cases. For these, the following lemma is convenient. Here we let o(x) denote the order of an element x. Lemma. Let x and y be noncommuting elements of a 2-group P. Suppose that o(x), o(y)^4 and furthermore that if o(x)=o(y)=4 then (x)(~\(y) = (1). Then Zi \ Z2 is involved in P. Proof. Clearly Z2 ^ Z2 is the dihedral group of order 8. Suppose first that o(x) =0(3') =2. If u = xy then we have easily ux = u~1. Since x and u do not commute o(w) 5^4 and thus if v is a suitable power of w Presented to the Society January 24, 1968 under the title The unit group of a modular group algebra; received by the editors July 28, 1969. AMS Subject Classifications. Primary 2080, 2040.