Miracle-dz/UniFAR-FTUs huggingface dataset:
Saturation Effect on Photoionization-driven Broad Absorption Line Variability

We study the saturation effect on broad absorption line (BAL) variability through a variation phenomenon, which shows significant variation in Si IV BAL but no, or only small, change in C IV BAL (hereafter Phenomenon I). First, we explore a typical case showing Phenomenon I, quasar SDSS J153715.74+582933.9 (hereafter J1537+5829). We identify four narrow absorption line (NAL) systems within its Si IV BAL and two additional NAL systems within its C IV BAL, and confirm their coordinated weakening. Combining with the obvious strengthening of the ionizing continuum, we attribute the BAL variability in J1537+5829 to the ionization changes caused by the continuum variations. Secondly, a statistical study based on multiobserved quasars from SDSS-I/II/III is presented. We confirm that (1) the moderate anticorrelation between the fractional variations of Si IV BALs and the continuum in 74 quasars that show Phenomenon I and (2) the sample showing BAL variations tends to have larger ionizing continuum variations. These results reveal the ubiquitous effect of the continuum variability on Phenomenon I and BAL variation. We attribute the relative lack of variation of C IV BALs in Phenomenon I to the saturation effects. Nonetheless, these absorbers are not very optically thick in Si IV and the ionization changes in response to continuum variations could be the main driver of their variations. Finally, we find that the saturation effect on BAL variability can well explain many phenomena of BAL variations that have been reported before.
Quantitative aspects of entanglement in the driven Jaynes–Cummings model

Adopting the framework of the Jaynes–Cummings model with an external quantum field, we obtain exact analytical expressions of the normally ordered moments for any kind of cavity and driving fields. Such analytical results are expressed in the integral form, with their integrands having a commom term that describes the product of the Glauber–Sudarshan quasiprobability distribution functions for each field, and a kernel responsible for the entanglement. Considering a specific initial state of the tripartite system, the normally ordered moments are then applied to investigate not only the squeezing effect and the nonlocal correlation measure based on the total variance of a pair of Einstein–Podolsky–Rosen type operators for continuous variable systems, but also the Shchukin–Vogel criterion. This kind of numerical investigation constitutes the first quantitative characterization of the entanglement properties for the driven Jaynes–Cummings model.
What drives the radio slopes in radio-quiet quasars?

The origin of the radio emission in Radio Quiet (RQ) quasars is not established yet. Important hints can be provided by the spectral slope, and its relation to other emission properties. We compiled the highest resolution 5 and 8.4 GHz VLA observations available of the RQ optically selected PG quasars at z 0.3) quasars have a steep slope (alpha_R -0.5), indicative of a compact optically thick synchrotron source. Flat alpha_R quasars also have a low Fe II/Hbeta line ratio, and a flat soft X-ray slope. The 16 Radio Loud (RL) PGs do not follow the RQ quasar set of correlations, and their alpha_R is set by M_BH, suggesting that the radio emission mechanisms in RL and RQ quasars are different. A possible interpretation is that high L/L_Edd RQ quasars produce a strong outflow and an associated optically thin synchrotron emission. In lower L/L_Edd RQ quasars, the strong outflow is missing, and only a compact optically thick radio source remains, possibly associated with the accretion disk coronal emission. A systematic study of RQ quasars at higher frequencies, and higher resolution, can test whether a compact flat source indeed resides in the cores of all RQ quasars, and allow the exploration of its relation with the coronal X-ray emission.
Dual hybrid convolutional generative adversarial network for hyperspectral image classification

ABSTRACT Generative adversarial networks (GANs) have effectively promoted the development of hyperspectral image classification technology in generating samples. Many GAN-based models for hyperspectral image classification use deconvolution to generate fake samples, which will cause chequerboard artefacts and affect classification performance. Furthermore, the training of GANs still faces the problem of mode collapse. Aiming at the above problems, we proposed a dual hybrid convolutional generative adversarial network (DHCGAN) for hyperspectral image classification. Firstly, the combination of nearest neighbour upsampling and sub-pixel convolution is employed in the generator, which avoids the overlap of convolution domain and effectively suppresses the chequerboard artefacts caused by deconvolution. Secondly, the traditional convolution and dilated convolution are fused in the discriminator, which expands the receptive field without increasing parameters and achieves more effective feature extraction. In addition, some adaptive drop blocks are embedded into the generator and discriminator to effectively alleviate the problem of mode collapse. Experiments were performed on four hyperspectral datasets (including three classical datasets – Indian Pines, University of Pavia and Houston, a new dataset – WHU-Hi-HanChuan). Experimental results show that the proposed method can provide a certain performance improvement over some competing methods, such as the accuracy has been increased by more than 1% on the three classical datasets, and even got over 3% improvement on WHU_Hi_HanChaun dataset.
Semiconducting to metallic transition in CX(BN)Y nanotubes: effects of C stripes in BN basis

In this work, we study the structural and electronic properties of CX(BN)Y nanotubes, varying the CX concentration in the BN base structure. The developed work was done combining semiempirical, density functional theory (DFT) and Green’s function calculation methods. In the first part, we shown by structure energies that the distribution of B − C, C − N, C − C, and B − C chemical bonds greatly influence the structural stabilization of the nanotubes and the integration of the carbo (C) atoms within the CX(BN)Y systems has a strong dependence on the atomic distribution of B, C, and N atoms. In the second part, we shown that atomic distribution of B, C, and N atomos has also a strong impact on the electronic band gap, transforming the electronic structure of initial BN electronic configurations.
Light force fluctuations in a strongly coupled atom–cavity system

Between mirrors, the density of electromagnetic modes differs from the one in free space. This changes the radiation properties of an atom as well as the light forces acting on an atom. It has profound consequences in the strong-coupling regime of cavity quantum electrodynamics. For a single atom trapped inside the cavity, we investigate the atom–cavity system by scanning the frequency of a probe laser for various atom–cavity detunings. The avoided crossing between atom and cavity resonance is visible in the transmission of the cavity. It is also visible in the loss rate of the atom from the intracavity dipole trap. On the normal-mode resonances, the dominant contribution to the loss rate originates from dipole-force fluctuations which are dramatically enhanced in the cavity. This conclusion is supported by Monte Carlo simulations.
Students' Perception of ODL Using Telegram as a Japanese Language Learning Platform

Since the beginning of 2020 following the spread of the COVID-19 epidemic, ODL has become the new norm in education either at the primary school level or in higher education institutions. This study is motivated to identify the student's perception of the teaching and learning platform chosen by the instructor so that the ODL session can be optimized and will successfully assist the students’ attainment of the Japanese language course. The purpose of this study is to investigate how students perceive Telegram as an ODL platform for learning Japanese. This quantitative study used a 5-point Likert scale as an instrument. The survey was divided into five sections. Section A was the demographic profile, Section B was Learner-to-Learner Interaction, Section C was Learner-to-Instructor Interaction, Section D was Learner-to-Content Interaction and Section E was Learner-to-Platform Interaction. There are 26 items for the Four Types of Interactions. 186 students learning Introductory Japanese Level II participated in this survey. Data is analyzed using SPSS Frequency Statistics, Descriptive Statistics and Paired Samples T-Test. The findings of the study show that students agree with the choice of Telegram as an online Japanese learning platform and the interaction between students, instructors, content and platform is positive. It is suggested that qualitative studies are also conducted to explore more about their perceptions of Telegram being a platform for ODL. analyzed using SPSS version 26 Frequency Statistics for the demographic profile, Descriptive Statistics for all Likert’s and Paired Samples T -Test for comparison between Learner-to-Learner Interaction and Learner-to-Instructor Interaction to reveal the percentage and mean scores.
Quantum magnetism in minerals

The discovery of magnetism by the ancient Greeks was enabled by the natural occurrence of lodestone – a magnetized version of the mineral magnetite. Nowadays, natural minerals continue to inspire the search for novel magnetic materials with quantum-critical behaviour or exotic ground states such as spin liquids. The recent surge of interest in magnetic frustration and quantum magnetism was largely encouraged by crystalline structures of natural minerals realizing pyrochlore, kagome, or triangular arrangements of magnetic ions. As a result, names like azurite, jarosite, volborthite, and others, which were barely known beyond the mineralogical community a few decades ago, found their way into cutting-edge research in solid-state physics. In some cases, the structures of natural minerals are too complex to be synthesized artificially in a chemistry lab, especially in single-crystalline form, and there is a growing number of examples demonstrating the potential of natural specimens for experimental investigations in the field of quantum magnetism. On many other occasions, minerals may guide chemists in the synthesis of novel compounds with unusual magnetic properties. The present review attempts to embrace this quickly emerging interdisciplinary field that bridges mineralogy with low-temperature condensed-matter physics and quantum chemistry.
Streaming-enhanced flow-mediated transport

We investigate the ability of an active body (master) to manipulate a passive object (slave) purely via contactless flow-mediated mechanisms, motivated by potential applications in microfluidic devices and medicine (drug delivery purposes). We extend prior works on active–passive cylinder pairs by superimposing periodic oscillations to the master’s linear motion. In a viscous fluid, such oscillations produce an additional viscous streaming field, which is leveraged for enhancing slave transport. We see that superimposing oscillations robustly improves transport across a range of Reynolds numbers. Comparison with results without oscillations highlights the flow mechanisms at work, which we capitalize on to design (master) geometries for augmented transport. These principles are found to extend to three-dimensional active–passive shapes as well.
Correlations and structures in modern galaxy redshift surveys

The new generation galaxy redshift surveys which became available over the last five years are first to provide three-dimensional maps containing hundreds of thousands of the local galaxies. These new data allow researchers to extend the range of scales available for correlation analysis to more than 100 Mpc/h. Correlations in the volume limited samples extracted from the latest available versions of 2dF and SDSS galaxy catalogs are characterized using the conditional density and the reduced two-point correlation function. For the conditional density a power-law behavior is detected in the range of scales from about 0.5 Mpc/h to 30 Mpc/h, having an exponent 2 . 0 8 . 0 ± = γ for the 2dF and 1 . 0 9 . 0 ± = γ for the SDSS. Extending analysis to the larger scales using the SDSS data shows an evidence of possible homogeneity detection with the conditional density going towards a constant value; reliability of this evidence is then discussed. The samples are then tested for a presence of the super-large structures or systematic biases which may affect correlation analysis using simple methods of the differential number counts and the radial density distribution.
Feature Points on Point-based Surface and Their Applications

Surface acquisition methods are becoming popular for many practical applications in manufacturing, art, and design. With the growing amount of geometric data, efficient tools for matching and recognition of complex surfaces become more important. In order to achieve such efficiency, many existing methods operate on a limited subset of feature points sampled from the surfaces, often randomly. In this thesis, we introduce an alternative way to achieve the efficiency by detecting a set of salient feature points from complex 3D geometry data. The method builds a scale-space representation for the input surface and use local extrema of the difference along normal direction between neighbor scales as salient points (or features). For every feature detected, we define a point signature vector that reflects the variation of local surface normals. Salient points and their signatures are invariant to rigid transformation and are stable under surface variation. This provides a good basis for a single feature to find its correct match with good probability in a large database of features. We show the effectiveness of selected features and their signatures by applying them to solve several 3D computer vision problems. We first use the features for pairwise surface registration that matches two partial surface scans or matches a partial scan to its CAD model. The result of pairwise surface matching is used to align multi-view scans of the same object to reconstruct the complete model. We also use the selected features and their signatures for 3D object recognition, and evaluate their performance on both synthetic and real world 3D data with clustering and occlusion. Experiments demonstrate that the proposed features and signatures are robust for the applications.
Estimation et comparaison de niveaux de retour pour les vitesses extrêmes des vents

Several modelling of extreme values (here maximum daily wind speed) are possible: • Generalized Extreme Value Distributions (Frechet, Gumbel or Weibull) whose parameters can be estimated either by maximum likelihood or by probability weighted moments. Hypotheses required for this model are not always verified. Except for the Weibull distribution, the estimation of return levels above 50 years gives unexploitable confidence intervals. Depending on the meteorological stations, the distributions may be different. • Peak Over Threshold method and Generalized Pareto Distribution. But to determine the threshold is not so easy and the required hypotheses restricting. Depending on the methods different results are noticed for the same phenomenon. This shows that this modelling, imperative due to very little extreme data, implies delicate statistical investigations and to be careful when using the results, an exact validation seeming not possible.
Recovery of bacterioruberin and proteins using aqueous solutions of surface-active compounds

Haloarchaea microorganisms are little explored marine resources that can be a promising source of valuable compounds with unique characteristics, due to their adaptation to extreme environments. In this work, the extraction of bacterioruberin and proteins from Haloferax mediterranei ATCC 33500 was investigated using aqueous solutions of ionic liquids and surfactants, which were further compared with ethanol. Despite the good performance of ethanol in the extraction of bacterioruberin, the use of aqueous solutions of surface-active compounds allowed the simultaneous release of bacterioruberin and proteins in a multi-product process, with the non-ionic surfactants being identified as the most promising. The optimum operational conditions allowed a maximum extraction yield of 0.37 ± 0.01 mgbacterioruberin gwet biomass−1 and 352 ± 9 mgprotein gwet biomass−1 with an aqueous solution of Tween® 20 (at 182.4 mM) as the extraction solvent. In addition, high purities of bacterioruberin were obtained, after performing a simple induced precipitation using ethanol as an antisolvent to recover the proteins present in the initial extract. Finally, a step for polishing the bacterioruberin was performed, to enable solvent recycling, further closing the process to maximize its circularity.
Corrections to "Advancements in codes for computer aided design of depressed collectors and tracing

The BSCAT computer code being developed by us for the design of depressed collectors for gyrotrons employs a special algorithm for tracing the trajectories of backscattered electrons. Monte Carlo techniques are used on a large ensemble of rays to ensure accurate representation of the stochastic process. Recent work has focused on improvement of the modeling of the electron backscatter phenomenon itself. We have introduced more accurate models for the backscatter coefficients for true secondaries, as well as elastically and inelastically backscattered primaries. These models are adapted to the energy ranges and the angles of incidence of the primaries. They are linked with experimental data as available in current literature or with Monte Carlo simulations. Analytical representations have been used where they closely approximate the experimental or simulation data, in an effort to make the computation as versatile and computationally inexpensive as feasible. The same has been done for angular and energy distributions of the emitted electrons.
w∞ algebras, conformal mechanics and black holes

We discuss BPS solitons in gauged = 2, D = 4 supergravity. The solitons represent extremal black holes interpolating between different vacua of anti-de Sitter spaces. The isometry superalgebras are determined and the motion of a superparticle in the extremal black hole background is studied and confronted with superconformal mechanics. We show that the Virasoro symmetry of conformal mechanics, which describes the dynamics of the superparticle near the horizon of the extremal black hole under consideration, extends to a symmetry under the w algebra of area-preserving diffeomorphisms. We find that a Virasoro subalgebra of w can be associated with the Virasoro algebra of the asymptotic symmetries of AdS 2 . In this way spacetime diffeomorphisms of AdS 2 translate into diffeomorphisms in phase space: our system offers an explicit realization of the AdS 2 /CFT 1 correspondence. Using the dimensionally reduced action, the central charge is computed. Finally, we also present generalizations of superconformal mechanics which are invariant under = 1 and = 2 superextensions of w .
Joint galaxy - lensing observables and the dark energy

Deep multicolor galaxy surveys with photometric redshifts will provide a large number of two-point correlation observables: galaxy-galaxy angular correlations, galaxy-shear cross correlations, and shear-shear correlations between all redshifts. These observables can potentially enable a joint determination of the dark-energy-dependent evolution of the dark matter and distances as well as the relationship between galaxies and dark matter halos. With recent cosmic microwave background determinations of the initial power spectrum, a measurement of the mass clustering at even a single redshift will constrain a well-specified combination of dark energy (DE) parameters in a flat universe; we provide convenient fitting formulas for such studies. The combination of galaxy-shear and galaxy-galaxy correlations can determine this amplitude at multiple redshifts. We illustrate this ability in a description of the galaxy clustering with 5 free functions of redshift which can be fitted from the data. The galaxy modeling is based on a mapping onto halos of the same abundance that models a flux-limited selection. In this context and under a flat geometry, a 4000 deg${}^{2}$ galaxy-lensing survey can achieve a statistical precision of $\ensuremath{\sigma}({\ensuremath{\Omega}}_{\mathrm{DE}})=0.005$ for the dark energy density, $\ensuremath{\sigma}{(w}_{\mathrm{DE}})=0.02$ and $\ensuremath{\sigma}{(w}_{a})=0.17$ for its equation of state and evolution, evaluated at dark energy matter equality $z\ensuremath{\approx}0.4,$ as well as constraints on the 5 halo functions out to $z=1. $ More importantly, a joint analysis can make dark energy constraints robust against systematic errors in the shear-shear correlation and halo modeling.
DNA Electromagnetic Properties and Interactions

DNA is an essential molecule central to the survival and propagation of life, it was imperative to investigate possible electromagnetic properties inherent to it, such as the existence of any non-trivial interactions of this molecule with electromagnetic fields (beyond the usual dielectric response and damage by ionizing gamma radiations). Extensive investigations were carried out with both prokaryotic and eukaryotic purified DNA samples utilizing some of the most sensitive and precision instrumentation and methods available, while scanning the whole spectral region from 1Hz to 100KHz (in the low frequencies) and all the way to the high-frequency region of 100MHz (including investigations on the effects of 100MHz high-frequency fields as well as 2.4GHz microwave fields on the DNA). We were unable to detect any electromagnetism of any kind intrinsic to the DNA or its coupling to external noise sources, whether concentrated or diluted in water, as compared to control samples (H2O or empty chambers), neither existence of any possible spontaneous or stimulated/induced electromagnetic fields or waves emanated from both the eukaryotic and prokaryotic genetic material. Based on our measurements, we conclude that either there is no intrinsic electromagnetic activity or fields present in the DNA material, in both concentrated or diluted form, or any such activity is extremely weak in its intensity and beyond the measurement limits of current scientific methods.
Neutron width statistics in a realistic resonance-reaction model

Recent experiments on $s$-wave neutron scattering from $^{192,194,196}$Pt found that the reduced neutron width distributions deviated significantly from the expected Porter-Thomas distribution (PTD). Several explanations have been proposed for this PTD violation within the statistical model of compound nucleus reactions. Here, we study the statistics of the reduced neutron widths in the reaction $n+ ^{194}$Pt within a model that combines the standard statistical model of the compound nucleus with a realistic treatment of the neutron channel. We find that the reduced width distribution is well described by the PTD for a reasonable range of the neutron-nucleus coupling strength and depth of the neutron channel potential. We also find that the energy dependence of the average width in the presence of a near-threshold bound or virtual state of the neutron channel potential differs from the $\sqrt{E}$ dependence, commonly assumed in experimental analysis, and is in excellent agreement with the analytic form proposed by H. A. Weidenm\"uller [1]. In these cases, the reduced neutron width distributions extracted using the $\sqrt{E}$ dependence are significantly broader than the PTD.