Miracle-dz/UniFAR-FTUs huggingface dataset:
Topological phase in molecular bound states: Application to the E⊗e system

We extend recent works of Berry, Simon, and others on the evolution of adiabatic wave functions in parameter spaces with nontrivial global geometry, to show the interesting ways in which wave functions can acquire nonintegrable phase (commonly termed Berry’s phase, geometric phase, or topological phase) upon transport along paths in the parameter space. We emphasize the case of arbitrary paths on the Born–Oppenheimer potential energy surfaces (the parameter space of the electronic states in an isolated molecule) of the linear plus quadratic E⊗e Jahn–Teller system. It is found that these surfaces are degenerate not only at the origin but also at three other, equivalent points, which lie on a radius ρ=2k/g. Here k and g are the linear and quadratic vibronic coupling constants, respectively. This radius is then shown to mark a sharp transition between Jahn–Teller behavior, characterized by half‐odd‐integral vibronic angular momentum, and Renner–Teller behavior, which has integral angular momentum. Finally, w.
Feedback linearization control for active filters

This paper presents the application of the feedback linearization theory to a three-phase shunt active lter. The solution is performed in a synchronous reference frame, dealing with multivariable aspects of system. The proposed control ensures a proper operation of active lter, allowing to achieve high power factor of the grid independent of constants obtained by operation points. Experimental results obtained from a prototype are presented in order to validate the proposed strategy, covering the analysis from stationary and transient responses.
Edge-coherent-mode nature of the small edge localized modes in Experimental Advanced Superconducting Tokamak

High-confinement regime with high-frequency and low-energy-loss small edge localized modes (ELMs) was achieved in Experimental Advanced Superconducting Tokamak by using the lower hybrid current drive and ion cyclotron resonance heating with lithium wall conditioning. The small ELMs are usually accompanied with a quasi-coherent mode at frequency around 30 kHz, as detected by the Langmuir probes near the separatrix. The coherent mode, with weak magnetic perturbations different from the precursor of conventional ELMs, propagates in the electron diamagnetic drift direction in the lab frame with the poloidal wavelength λθ ∼ 14 cm, corresponding to both high poloidal and toroidal mode numbers (m > 60 and n > 12). This coherent mode, carrying high-temperature high-density filament-like plasma, drives considerable transport from the pedestal region into the scrape-off layer towards divertor region. The co-existence of small ELMs and quasi-coherent modes is beneficial for the sustainment of long pulse H-mode regime without significant confinement degradation.
Real-time restoration of rotational blurred image using gradient-loading

The key to the restoration of rotational motion blurred image is how to restore the image under a low cost and to correct the irreversibility of the degradation function matrix. Based on the special qualities of degradation function matrix and precise deduction in space-domain, we present a new approach using gradient-loading for restoration of rotational blurred image. By easily adding a gradient operator, the irreversibility of the original matrix is corrected and can be applied for inverse filtering then. Gradient-loading is the optimized approach which combines the advantages of both the approaches using constrained least square filtering and traditional diagonal-loading. Compared with the approach using least square filtering, its peak signal-to-noise ratio (PSNR) is improved from 3.18 to 6.46 dB, while the computing time is reduced to 1/2-1/3. Experimental results demonstrate the effectiveness, noise-resistibility, robustness, and low complexity of this approach, which make it more suitable for real-time environment.
Chaos in Lifshitz spacetimes

We investigate the chaotic behavior of a circular test string in the Lifshitz spacetimes by considering the critical exponent z as an external control parameter. We demonstrate that two primary tools to observe chaos in this system are the Poincaré section and the Lyapunov exponent. Finally, the numerical result shows that if z = 1, the string dynamics is regular while in a case slightly larger than z = 1, the dynamics can be irregular and chaotic, which implies that the space time anisotropy, which breaks Lorentz symmetry, may cause the system to be chaotic.
A BOTTOM-UP METHOD TO BUILD 3D SCAFFOLDS WITH PREDEFINED VASCULAR NETWORK

Tissue engineering is a promising approach to regenerate transplantable tissue or organ substitutes in vitro. However, the existing methods are based on seeding cells on macroscale polymer scaffolds, which are associated with several challenges including limited control over cell microenvironment, limited nutrient diffusion, directed cell alignment. The emerging bottom-up tissue engineering methods hold great potential to address these challenges by assembling building blocks into complex 3D tissue constructs. In this study, we developed a layer-by-layer assembly approach to recreate 3D cell-laden constructs. Our experiment showed the predefined channels form a vascular system and help the transplant cells to transport the requirement of culture cells in early case of cells attaching and growing up. It is an original concept to demonstrate the feasibility of forming a network with a vascular geometry in a biocompatible polymer and fabricated different scaffold with different cells. The concept was developed to create a complete branching vascular circulation in 3D on surface of mixture of chitosan and gelatin structures and pre-define the structure of channel for culturing smooth muscle for controlling the SMC growing up as smooth muscle fiber.
Color image coding using variable blocksize vector quantization in (R,G,B,) domains

Vector Quantization (VQ) is a popular image coding scheme with high data compression ratio. However, its major drawback is the edges in the reconstructed image are very poor if the codebook size isn't large enough. In this paper, we use the Variable Blocksize Vector Quantization (VBVQ) instead of a fixed blocksize VQ to code color images in the (R, G, B) domain. In order to alleviate block effect and preserve the edge well, we choose 4 X 4 X 3 as the largest block and 1 X 1 X 3 as the smallest block. For each blocksize we generate a codebook by using LBG's algorithm. The image is first decomposed into variable blocks and each block uses its corresponding codebook for vector quantization. In our simulation results, the bit rate is from 0.4 bpp (bit per pixel) to 1.1 bpp with PSNR (peak signal to noise ratio) of Y component from 28 db to 36 db. Our VBVQ outperforms conventional fixed blocksize 2 X 2 X 3 VQ with 512 codevectors in the codebook.
Spectral characteristics of 3U1915-05, a burst source candidate

An X-ray burst source was discovered near the X-ray source 3U1915-05. The continuum spectra of both the burst source and the quiescent 3U1915-05 are hard, with kT above 20 keV. The spectrum of 3U1915-05 has a feature at 9.1 keV, which, if attributed to absorption by hydrogen and helium-like iron, suggests the presence of a highly ionized cloud surrounding a central X-ray source.
Design and fabrication of SU-8 polymer-based micro-racetrack resonators

By using small SU-8 polymer ridge waveguides, compact micro-racetrack resonator (MRR) add-drop filters are presented. This used small ridge waveguide has an air-cladded SU-8 polymer core (n~1.573) on a SiO2 buffer (n~1.445) so that the bending radius could be as small as ~102μm. Considering the resolution limitation of a regular UV-lithography process, the gap in the coupling region of the present MRR in our design is no less than 1.0 μm. In order to enhance the coupling between the access optical waveguide and the micro-racetrack, narrow optical waveguides are used in the coupling regions. Meanwhile, wide optical waveguides are used in the bending sections to have a small bending radius. And a single-side taper is used to connect these two sections with different widths so that the gap width is kept as small as 1.0 μm in the whole region. With a regular UV lithography process, the designed micro-racetrack resonator (MRR) add-drop filters are fabricated. The measured propagation loss for straight waveguides is about 0.1dB/mm and the measured spectral responses of the through/drop ports show a Q-factor of 8000.
Charge transport and thermoelectric properties of double-filled Nd1–zYbzFe4–xCoxSb12 skutterudites

p-Type Nd1–zYbzFe4–xCoxSb12 (z = 0.25, 0.5, 0.75 and x = 0, 0.5, 1.0) skutterudites were synthesized by using encapsulated melting and hot pressing. The effects of Nd/Yb double filling and Co substitution for Fe (charge compensation) on the microstructure, the charge transport, and the thermoelectric properties of the skutterudite specimens were investigated. All specimens were transformed to the skutterudite phase by the annealing process, and a few secondary phases such as marcasite FeSb2 were formed together with the skutterudite phase, although their formation was suppressed with increasing Co content. The lattice constant changed with the filling ratio of Nd/Yb and Fe/Co substitution, which meant that the double filling of Nd/Yb and the substitution of Co for Fe were successfully performed. All specimens showed p-type conduction at temperatures ranging from 323 K to 823 K and exhibited degenerate semiconductor characteristics, in which the electrical conductivity decreased and the Seebeck coefficient increased with increasing temperature. The Seebeck coefficient increased with increasing Nd and Co contents due to the decreased carrier concentration while the electrical conductivity and the thermal conductivity decreased. The maximum Seebeck coefficient was obtained at temperatures in the range from 723 K to 823 K, and the thermal conductivity significantly increased at temperatures above 623 K due to bipolar conduction. The dimensionless figure of merit, ZT, showed maximum values at temperatures ranging from 723 K to 823 K due to the decrease in the Seebeck coefficient (or the decrease in the power factor) and the increase in the thermal conductivity at high temperatures. The maximum ZT = 0.81 was obtained for Nd0.75Yb0.25Fe4Sb12 at 823 K and for Nd0.75Yb0.25Fe3CoSb12 at 723 K.
Tunable Metamaterial Absorber Using Ferromagnetic Resonance

We simulated a study on a tunable metamaterial absorber using ferrite rubber as a dielectric substrate with ferromagnetic properties. The proposed structure employs ferromagnetic resonance, which utilizes the coupling of an applied magnetic field and an incident electromagnetic wave. As the magnitude of the applied magnetic field increases, it can be seen that the absorption peak moves to a higher frequency. The adjustment of the absorption frequency using the proposed method is expected to be applied to various fields such as sensors, electronic devices and 5G communication antennas.
Asymptotic Investigation of the Information Rates in Certain Stationary Channels with and without Memory

SYNOPTIC ABSTRACT A short review and new results on the asymptotic investigation of the information rates in weak signal transmission over certain stationary channels are presented. Channels with an additive Gaussian and non-Gaussian noise as well as some models of channels with an additive-multiplicative noise with and without memory are considered.
The role of autoionizing states in two-photon dissociative ionization of H2 by xuv ultrashort laser pulses

A theoretical study of two-photon ionization of H2 by low-intensity ultrashort xuv laser pulses is reported. The method is based on the solution of the time-dependent Schrödinger equation in a basis of stationary molecular vibronic states which include all electronic and vibrational degrees of freedom. In contrast with previous work, the doubly excited states, which also contribute to the ionization probabilities through autoionization, are explicitly included. We have found that, just below the one-photon ionization threshold, molecular autoionization leads to an enhancement of dissociative ionization, whose corresponding probability can be an order of magnitude larger than that of the nondissociative ionization process, and even larger than the corresponding dissociative probability in the one-photon absorption region. This result suggests that multicoincidence experiments, in which the orientation of the molecule with respect to the polarization axis is determined, might be easier to perform in the two-photon absorption regime than in the one-photon absorption regime. Electron angular distributions in the same range of photon energies are also reported.
On the probability density of signal-to-noise ratio in an improved adaptive detector

The main advantage of our previously presented [10] principal-component method of adaptive detection, in comparison with the method based on the inverse of the estimated covariance matrix, is that much less data is required to produce a given, needed level of SNR with high probability. In this paper we present an outline of the derivation of the approximate probability density of the SNR for this adaptive detector. To simplify the derivation we assume that the noise consists of a strong gaussian rank-one-covariance interference component plus a component of white gaussian background noise. The approximations and the final probability density are tested through simulation.
Development of a GOES-R Advanced Baseline Imager Solar Channel Radiance Simulator for Ice Clouds

AbstractThis paper describes the development of an ice cloud radiance simulator for the anticipated Geostationary Operational Environmental Satellite R (GOES-R) Advanced Baseline Imager (ABI) solar channels. The simulator is based on the discrete ordinates radiative transfer (DISORT) model. A set of correlated k-distribution (CKD) models is developed for the ABI solar channels to account for atmospheric trace gas absorption. The CKD models are based on the ABI spectral response functions and also consider when multiple gases have overlapping absorption. The related errors of the transmittance profile are estimated on the basis of the exact line-by-line results, and it is found that errors in transmittance are less than 0.2% for all but one of the ABI solar channels. The exception is for the 1.378-μm channel, centered near a strong water vapor absorption band, for which the errors are less than 2%. For ice clouds, the band-averaged bulk-scattering properties for each ABI [and corresponding Moderate Resolut.
Computational Aspects of the Cell Method in Electrodynamics - Abstract

A desire to unify the mathematical description of many physical theories, such as electrodynamics, mechanics, thermal conduction, has led us to understand that global (=integral) physical variables of each theory can be associated to spatial geometrical elements such as points, lines, surfaces, volumes and temporal geometrical elements such as instant and interval. This association has led to the building of a space-time classification diagram of variables and equations of each theory. Moreover, the possibility to express physical laws directly in a finite rather than differential form has led to the development of a computational methodology called Cell Method [? ]. This paper discusses some practical aspects of this method and how it may overcome some of the main limitations of FDTD method in electrodynamics. Moreover, we will provide some numerical examples to compare the two methodologies.
Characterization of optical trap for metallic particles using external magnetic field

We report a method to optically trap and micromanipulate metallic particles using IR laser. The experiment demonstrates the trapping of metallic particle using low NA objective lens (0.6 N.A). Unlike single beam gradient trapping of dielectric objects, the optical trapping of metallic particles occurs due to diffraction effect. We thus provide evidence for non-gradient forces playing a dominant role in the trapping of metallic particles, in here for the case of 3μm Fe particles, efficient trapping occurs at off-axis position (in the side lobes) of a focused laser beam. The optical trap is characterized by measuring the external magnetic field required to dislodge the Fe particle, and was found to be 0.03T to 0.11T for laser power 5 to 55mW at the sample.
Calculations of electron-impact single-ionization cross sections of helium isoelectronic systems

The electron-impact single-ionization cross sections on the helium isoelectronic targets He, Li{sup +}, B{sup 3+}, C{sup 4+}, N{sup 5+}, O{sup 5+}, Ne{sup 8+}, Na{sup 9+}, Fe{sup 24+}, Ag{sup 45+}, and U{sup 90+}, are calculated using the recent simplified version of the binary-encounter dipole (siBED) model as applied by Huo [Phys. Rev. A 64, 042719 (2001)] to various molecular targets. The simple siBED model is good for the helium atom, but it is inadequate for ionic targets. Our proposed modifications: (i) ionic correction of the siBED model (QIBED) and (ii) relativistic corrections of the siBED model (RQIBED) are examined on a wider group of species and compared with other available experimental and theoretical results. The predictions of QIBED in the nonrelativistic energy domain and of RQIBED for all energies, with the same parameter values of siBED, produce excellent agreement with the experimental data and the results close to those of other theories for all the two-electron systems, neutral or ions on the same footing.
Optical observations of NGC 2915: a nearby blue compact dwarf galaxy

This paper presents B and R band Charge Coupled Device (CCD) images and medium resolution spectroscopy of NGC 2915, a relatively isolated BCD (blue compact dwarf) galaxy at a distance of approximately 5 Mpc. NGC 2915 contains two stellar populations: a high surface brightness blue core population and a red diffuse population. The core population contains all of the H II, and numerous embedded objects. It is the locus of current high mass star formation. The brightest embedded objects are likely to be young ionizing clusters, while many of the fainter objects are likely to be individual supergiant stars with masses up to approximately 25 solar mass, or blends of a few such stars. Curious aligned structures on the SE side of the galaxy are seen and their nature discussed. The spectrum of the core is dominated by bright narrow emission lines like that of a high excitation and low metallicity (less than half solar) H II region. The continuum is flat, with Balmer and Ca II features seen in absorption. The velocity of the Ca II features suggest contamination by galactic interstellar absorption. There is a significant velocity gradient in the spectra, probably indicative of rotation. Outside of its core, NGC 2915 resembles a dE (dwarf elliptical) galaxy, in that it has an exponential surface brightness profile, is red ((B-R)(sub 0) = 1.65), and has a low extrapolated central surface brightness (B(0)(sub c) = 22.44). NGC 2915's properties are compared with other BCDs, concentrating on two morphologically similar BCDs that are near enough to resolve into stars: NGC 1705 and NGC 5253. It is noted that the presence of winds in BCDs invalidates closed box chemical evolution models and the remaining constraints on star formation duration are relatively weak. Some BCDs, including NGC 2915, may be able to maintain their present star formation rate for Gyr time scales. This suggests that the overall evolution of these BCDs may be much slower than the approximately 10 Myr burst time scales commonly quoted. However, shortly after the formation of a massive (10(exp 6) solar mass) cluster a BCD will have all the properties of strong starburst galaxy).
GPU accelerated electric field Monte Carlo simulation of light propagation in turbid media using a finite-size beam model

An electric field Monte Carlo (EMC) simulation directly traces the complex electric field vectors in multiple scattering and estimates the electric field in a preferred direction. The full vectorial nature of EMC makes it a powerful and flexible tool to simulate the coherence and polarization phenomena of light. As a numerical method, EMC needs to launch a large number of photons to achieve an accurate result, making it time-consuming. Previously, EMC did not account for the beam size. Because of the stochastic character of the instantaneous electric field in the simulation, the convolution method alone is unsuitable for the Monte Carlo simulation of photon energy for a beam with a finite size. It is necessary to launch photons from all possible locations to simulate a finite-size beam, which results in a significant increase in the computational burden. In order to accelerate the simulation, a parallel implementation of the electric field Monte Carlo simulation based on the compute unified device architecture (CUDA) running on a graphics processing unit (GPU) is presented in this paper. Our program, which is optimized for Fermi architecture, is able to simulate the coherence phenomenon of a finite-size beam normally incident on turbid media. A maximum speedup of over 370x is achieved with a GTX480 GPU, compared with that obtained using an Intel i3-2120 CPU.
Space motions of globular clusters NGC 362 and NGC 6218 (M12)

We measured the absolute proper motions of NGC 6218 (M12) against distant galaxies and of NGC 362 against stars of the Small Magellanic Cloud (typical accuracy ±0″.13 cent −1 ). The results are combined with these of the two studied clusters NGC 4147 and NGC 5466. A variety of parameters is determined within the approximation of a simple Galactic potential, including the description of the last transits of the clusters through the main plane of the Galaxy.
The kinematic dynamo action of spiralling convective flows

We consider the kinematic production of magnetic fields in a sphere by velocity fields dominated by differential rotation and spiralling convective cells. The high magnetic Reynolds number limit of Braginsky (1964) is considered and formulae are derived allowing an α-effect parametrization of such flows to be easily calculated. This permits an axisymmetric system to be investigated in parallel with the direct 3-D numerical computations. Good agreement between the asymptotic and 3-D calculations is found. The ‘spiralling’ property typical of convective motion in rotating spheres is important in terms of dynamo action; the differential rotation coexisting with this feature is also vital. Indeed, it is the presence of both features which allows the analysis of Braginsky to be employed. With flows approximating the columnar form anticipated for rapidly rotating convection, dynamo action is relatively easily achieved for all azimuthal wavenumbers; modes of differing wavenumbers interact almost by a simple superposition. With flows of more complex latitudinal form, the mutual interactions between modes become more complicated. For columnar-type flows, dipole magnetic fields are favoured when the sense of outward spiralling is prograde and the zonal flow is eastwards, as is physically preferred.