Miracle-dz/UniFAR-FTUs huggingface dataset:
On‐chip stimulated Brillouin Scattering for microwave signal processing and generation

Demonstration of continuously tunable delay, low‐noise lasers, dynamically controlled gratings, and optical phase shifting using the stimulated Brillouin scattering (SBS) process has lead to the emergence of SBS as a promising technology for microwave photonics. On‐chip realization of SBS enables photonic integration of microwave photonic signal processing and offers significantly enhanced performance and improved efficiency. On‐chip stimulated Brillouin scattering is reviewed in the context of slow‐light based tunable delay, low‐noise narrow linewidth lasers and filtering for integrated microwave photonics. A discussion on key material and device properties, necessary to enable on‐chip Brillouin scattering using both the single‐pass and resonator geometry, is presented along with an outlook for photonic integration of microwave signal processing and generation in other platforms.
Adaptive RID kernels which minimize time-frequency uncertainty

The reduced interference distribution (RID) satisfies many of the desirable properties of time-frequency distributions (TFDs), including reduced interference. Using simple rules, it is possible to define kernels which guarantee the RID properties. A primitive h(t) is the starting point for kernel design. Starting with this primitive h(t), one may evolve a RID which enjoys all of the desirable properties. In addition, RIDs designed by this means also exhibit scale invariance in addition to the time-shift invariance and frequency-shift invariance exhibited by members of Cohen's class relevant to these properties. Such RIDs also exhibit a property which we call information invariance. Information invariance is defined under Renyi's generalized information. Renyi information has been found to be a useful quantifier of resolution in TFDs wherein minimum values of Renyi information are related to maximum resolution of the signal components. In this paper, we show that h(t) may be adapted to minimize Renyi information and thus achieve very good time-frequency resolution. <<ETX>>
Light scattering from a surfactant «sponge» phase: evidence for a hidden symmetry

New light-scattering data from an anomalous isotropic phase in a bilayer-forming surfactant system (sponge phase) are analysed using a Landau-Ginzburg theory with two fluctuating order parameters: one the surfactant density, and the other associated with an "inside/outside" (I/O) symmetry that arises in bilayer-containing systems. The scattering shows a clear signature of this additional order parameters. The concentration dependence of the osmotic compressibility provides strong evidence for fluctuation-induced logarithmic corrections to the elasticity and/or area parameters of the bilayer.
Various L2-signatures and a topological L2-signature theorem

For a normal covering over a closed oriented topological manifold we give a proof of the L2-signature theorem with twisted coefficients, using Lipschitz structures and the Lipschitz signature operator introduced by Teleman. We also prove that the L-theory isomorphism conjecture as well as the C^*_max-version of the Baum-Connes conjecture imply the L2-signature theorem for a normal covering over a Poincar space, provided that the group of deck transformations is torsion-free. We discuss the various possible definitions of L2-signatures (using the signature operator, using the cap product of differential forms, using a cap product in cellular L2-cohomology,.) in this situation, and prove that they all coincide.
Equilibration properties of classical integrable field theories

We study the equilibration properties of classical integrable field theories at a finite energy density, with a time evolution that starts from initial conditions far from equilibrium. These classical field theories may be regarded as quantum field theories in the regime of high occupation numbers. This observation permits to recover the classical quantities from the quantum ones by taking a proper ℏ→0 limit. In particular, the time averages of the classical theories can be expressed in terms of a suitable version of the LeClair–Mussardo formula relative to the generalized Gibbs ensemble. For the purposes of handling time averages, our approach provides a solution of the problem of the infinite gap solutions of the inverse scattering method.
Non-markovian entanglement dynamics of quantum continuous variable systems in thermal environments

We study two continuous variable systems (or two harmonic oscillators) and investigate their entanglement evolution under the influence of non-Markovian thermal environments. The continuous variable systems could be two modes of electromagnetic fields or two nanomechanical oscillators in the quantum domain. We use the quantum open system method to derive the non-Markovian master equations of the reduced density matrix for two different but related models of the continuous variable systems. The two models both consist of two interacting harmonic oscillators. In model A, each of the two oscillators is coupled to its own independent thermal reservoir, while in model B the two oscillators are coupled to a common reservoir. To quantify the degrees of entanglement for bipartite continuous variable systems in Gaussian states, logarithmic negativity is used. We find that the dynamics of the quantum entanglement is sensitive to the initial states, the oscillator-oscillator interaction, the oscillator-environment interaction and the coupling to a common bath or to different, independent baths.
Impact of liming on extractable phosphorus, exchangeable base cations, and effective cation exchange capacity of eastern Free State soils

Soil acidity can adversely affect wheat production in the eastern Free State, South Africa. Liming of the soils is therefore essential. The aim of this study was to establish whether extractable phosphorus (P), exchangeable calcium (Ca), magnesium (Mg) and potassium (K) concentrations and cation ratios remained within recommended ranges after liming. Incubation and field studies were done on soils of wheat fields at Kestell, Fouriesburg, Prinsloo and Melrose in the eastern Free State, South Africa. Lime was applied at different rates to induce soil acidity ranges for determination of Bray 1 extractable P and ammonium acetate (NH4OAc) exchangeable Ca, Mg and K concentrations. Cation ratios (Ca:Mg, Mg:K and (Ca + Mg):K) and effective cation exchange capacity (ECEC) were also calculated. Apart from the Prinsloo soil, liming decreased extractable P concentration only in the incubation study. In the incubation and field studies exchangeable Ca and Mg concentrations increased while exchangeable K concentration remained unchanged. Despite liming of the soils, exchangeable Ca and Mg concentrations at Kestell and Fouriesburg were still less than the required thresholds. The Ca:Mg ratio decreased at both sites while the Mg:K and (Ca + Mg):K ratios increased with liming. Liming increased ECEC of all soils at all four sites. Our results show that liming does not always result in the recommended cation levels required for soil fertility.
NARROW-BAND PHOTOMETRY AND THE EVOLUTION OF GALAXIES.

A new approach to the use of narrow-band filters in extragalactic research is described. The photometric system vz, bz, yz essentially imitates, at the redshift of the cluster of galaxies in question, the Strömgren v, b, y passbands. This system has some obvious advantages: the uncertainties associated with k-corretions are bypassed, and the passbands avoid the stronger emission lines appearing in the spectra of some normal and most active galaxies. It is necessary to acquire filters for each redshift value and to have accurate spectrophotometry for at least one galaxy at the redshift in order to calibrate the photometry. It is shown that the vz, bz, yz filter system is especially suitable for testing the evolutionary synthesis models. For that purpose 48 CCD frames of three clusters of galaxies (Abell 665, the small cluster around 3C 234, and Cl 1021.1+0427) were obtained. For galaxies, metric magnitudes were derived corresponding to a linear physical standard diameter of 32 kpc (H0 = 60 km s-1Mpc-1, q0 = 0.5). Galaxies showing a strong color gradient along their images (disk galaxies) are distinguished from galaxies with no, or very small, color gradient along their images (elliptical and lenticulars).
Constructing a Merged Cloud–Precipitation Radar Dataset for Tropical Convective Clouds during the DYNAMO/AMIE Experiment at Addu Atoll

AbstractTo improve understanding of the convective processes key to the Madden–Julian oscillation (MJO) initiation, the Dynamics of the MJO (DYNAMO) and the Atmospheric Radiation Measurement Program (ARM) MJO Investigation Experiment (AMIE) collected 4 months of observations from three radars—the S-band dual-polarization Doppler radar (S-Pol), the C-band Shared Mobile Atmospheric Research and Teaching Radar (SMART-R), and Ka-band ARM zenith radar (KAZR)—along with radiosonde and comprehensive surface meteorological instruments on Addu Atoll, Maldives, in the tropical Indian Ocean. One DYNAMO/AMIE hypothesis suggests that the evolution of shallow and congestus cloud populations is essential to the initiation of the MJO. This study focuses on evaluating the ability of these three radars to document the full spectrum of cloud populations and to construct a merged cloud–precipitation radar dataset that can be used to test this hypothesis. Comparisons between collocated observations from the three radars show .
Identification and Validation of Common Reference Genes for Normalization of Esophageal Squamous Cell Carcinoma Gene Expression Profiles

Esophageal squamous cell carcinoma (ESCC) is one of the subtypes of esophageal cancer with Chinese characteristics, and its five-year survival rate is less than 20%. Early diagnosis is beneficial to improving the survival rate of ESCC significantly. Quantitative Real-Time Polymerase Chain Reaction is a high-throughput technique that can quantify tumor-related genes for early diagnosis. Its accuracy largely depends on the stability of the reference gene. There is no systematic scientific basis to demonstrate which reference gene expression is stable in ESCC and no consensus on the selection of internal reference. Therefore, this research used four software programs (The comparative delta-Ct method, GeNorm, NormFinder, and BestKeeper) to evaluate the expression stability of eight candidate reference genes commonly used in other tumor tissues and generated a comprehensive analysis by RefFinder. Randomly selected transcriptome sequencing analysis confirmed the SPP1 gene is closely related to ESCC. It was found that the expression trend of SPP1 obtained by RPS18 and PPIA as internal reference genes were the same as that of sequencing. The results show that RPS18 and PPIA are stable reference genes, and PPIA + RPS18 are a suitable reference gene combination. This is a reference gene report that combines transcriptome sequencing analysis and only focuses on ESCC, which makes the quantification more precise, systematic, and standardized, and promotes gene regulation research and the early diagnosis of ESCC in the future.
Point singularities and conformal metrics on Riemann surfaces

Given a closed hyperbolic Riemann surface and a finite number of points, we prove the existence and uniqueness of hyperbolic conformai metrics with prescribed singularities or degeneracies at the given points. If M is a closed Riemann surface with negative Euler characteristic x(M), then it admits a compatible metric g with Gauss curvature K = — 1. If p e M, then we can ask for a compatible metric g on M = M \ {p} with Gauss curvature K = — 1 and some prescribed singularity or degeneracy at p, (1) g/g = 0(r2a) asr = r(x) = dist9(x,p)^0. Such singularities arise, for example, from maps which are locally z —► zm (z € C, m e Z+): pushing the standard metric forward gives a singularity corresponding to a = — (m — 1)/m and pulling back the standard metric gives a degeneracy corresponding to a = m — 1. Thus we are particularly interested in (1) with — 1 < a < oo. More generally, we can consider a finite number of points pi,. , pn e M and ai,. , a„ € R and try to find a compatible metric g on M = M \ {pi,. ,pn} with (2) g/g = 0(r2a') asrl=rl(x) = distg(x,pl)-+0. Our main result is the following. THEOREM. Let (M, g) be a compact Riemann surface with Gauss curvature K = — 1 and pi,. ,pn e M. Suppose the numbers cti,. , an satisfy (i) —1 < a¿ < oo, and (ii) x(M) + Et ai < 0Then M = M \ {p\,. ,pn} admits a unique metric g which is pointwise conformai to g, has Gauss curvature K = — 1, and satisfies (2). Moreover, g has total curvature (3) Jj-l)dÂ = 27rlx(M) + ̂ 2al\. PROOF. We shall assume for notational convenience that n = 1 but all steps of the proof generalize immediately. We want to solve (4) Au-e2u = -l on M = M\{p} Received by the editors November 14, 1986 and, in revised form, February 24, 1987. 1980 Mathematics Subject Classijication (1985 Revision). Primary 30F10; Secondary 35J60.
On the Structure and Variability of the Migrating Diurnal Temperature Tide Observed by SABER

Temperature observations made by the SABER infrared radiometer from January 2002 through December 2021 are used to study the structure and variability of the migrating diurnal temperature tide in the middle atmosphere (~17 to 105 km). In the lower stratosphere, and in the mesosphere and lower thermosphere (MLT), tidal structure is dominated by the gravest latitudinally symmetric mode, with a smaller contribution from the first anti-symmetric mode; in the middle and upper stratosphere, non-vertically propagating modes are prominent. Consistent with previous work, low-frequency variability is mainly semiannual, with maxima at the equinoxes. Quasi-biennial variability is also present and evident in low-passed time series. There are robust relationships between the semiannual and quasi-biennial variability of the tide and the semiannual and quasi-biennial tropical zonal wind oscillations, respectively, which persist throughout the 20-year dataset. While the physical mechanisms responsible for these relationships cannot be ascertained from the observations, the present results should be useful for hypothesis testing with numerical models. It is also found that the diurnal tide breaks due to convective instability in the MLT. This is reflected in its mean vertical structure, which grows as expected for a non-dissipating wave below ~85 km, but ceases to grow at higher altitudes. Direct confirmation that dissipation is due to breaking is obtained from the potential temperature field, which shows frequent instances of reversed vertical gradient, particularly at the equinoxes. Breaking of the diurnal tide has a major impact on the zonal-mean temperature and zonal wind structure of the MLT at the equinoxes.
A product integration method for the approximation of the early exercise boundary in the American option pricing problem

Integral equation methods are now becoming well‐established tools in the study of financial models used in theory and practice. In this paper, we investigate the fully nonlinear weakly singular nonstandard Volterra integral equations representing the early exercise boundary of American option contracts, which gained popularity in recent years. We propose a product integration approach based on linear barycentric rational interpolation to solve the problem. The price of the option will then be computed using the obtained approximation of the early exercise boundary and a barycentric rational quadrature. The convergence of the approximation scheme will also be analyzed. Finally, some numerical experiments based on the introduced method are presented and compared with some exiting approaches.
Biology learning tasks variation during COVID-19 pandemic and its effect on students’ self-efficacy

Changes in the learning process during the COVID-19 pandemic require quick adaptation from teachers and students to immediately achieve learning goals. However, it remains ineffective, resulting in a threat of learning loss. This condition can be overcome if students have confidence in their abilities or self-efficacy. It is important to do an analysis related to biology learning tasks taught by the teachers and students’ self-efficacy. This study aims to analyze biology learning tasks variation during the COVID-19 pandemic and its effect on students’ self-efficacy. This study used descriptive design with cross-sectional survey method. Samples were taken using the convenience sampling technique from five public schools. 446 students out of 465 total students and seven biology teachers participated in this study as respondents. The instruments used in this study were rubrics for quantifying learning tasks and self-efficacy questionnaires given to students after Biology Learning. The results show that all learning modes in Biology Learning during the COVID-19 pandemic have learning tasks that were more dominant in the low-level cognitive process. The dominant learning tasks include retrieval and comprehension, while learning tasks with a higher level of cognitive processing such as analysis, knowledge utilization, and metacognitive only cover a small part of the whole Biology learning process. There were no learning tasks that reached the highest level of cognitive process (self-system). The result of self-efficacy in all learning modes was high, but it was higher in learning modes that used hybrid learning. Biology learning tasks given by the teachers during the COVID-19 pandemic have an effect on students’ self-efficacy.
Long range random walks and associated geometries on groups of polynomial growth

In the context of countable groups of polynomial volume growth, we consider a large class of random walks that are allowed to take long jumps along multiple subgroups according to power law distributions. For such a random walk, we study the large time behavior of its probability of return at time $n$ in terms of the key parameters describing the driving measure and the structure of the underlying group. We obtain assorted estimates including near-diagonal two-sided estimates and the H\"older continuity of the solutions of the associated discrete parabolic difference equation. In each case, these estimates involve the construction of a geometry adapted to the walk.
On harmonic and pseudoharmonic maps from strictly pseudoconvex CR manifolds

In this paper, we give some rigidity results for both harmonic and pseudoharmonic maps from CR manifolds into Riemannian manifolds or Kahler manifolds. Some basicity, pluriharmonicity and Siu-Sampson type results are established for both harmonic maps and pseudoharmonic maps.
Small positive values for supercritical branching processes in random environment

Branching Processes in Random Environment (BPREs) $(Z_n:n\geq0)$ are the generalization of Galton-Watson processes where in each generation the reproduction law is picked randomly in an i.i. d. manner. In the supercritical case, the process survives with positive probability and then almost surely grows geometrically. This paper focuses on rare events when the process takes positive but small values for large times. We describe the asymptotic behavior of $\mathbb{P}(1 \leq Z_n \leq k|Z_0=i)$, $k,i\in\mathbb{N}$ as $n\rightarrow \infty$. More precisely, we characterize the exponential decrease of $\mathbb{P}(Z_n=k|Z_0=i)$ using a spine representation due to Geiger. We then provide some bounds for this rate of decrease. If the reproduction laws are linear fractional, this rate becomes more explicit and two regimes appear. Moreover, we show that these regimes affect the asymptotic behavior of the most recent common ancestor, when the population is conditioned to be small but positive for large times.
A general framework for comparing numerical uncertainty theories

Deciding which of the existing uncertainty theories is the appropriate one to use in the formalization of a given problem is still a difficult task. It is possible to compare these theories either using pragmatic considerations (e.g. efficiency) or experimentally applying them on a set of problems; however, up to now there is no general frame in which we can compare the uncertainty theories with respect to their meanings. Our work aims to develop a general formalism for representing and reasoning with uncertain knowledge, which provides such a framework and is not restricted in using one specific uncertainty theory as a basis. This formalism is based on the work of Carnap's logical foundation of probability. But, instead of propositions, we regard distinctions as elementary notions. Up until now, the following theories can be expressed within the framework: Bayes theory, fuzzy set theory, Dempster/Shafer theory (belief functions) and upper/lower probability theory.
Complementary co‐kriging: spatial prediction using data combined from several environmental monitoring networks

We consider the problem of optimal spatial prediction of an environmental variable using data from more than one sampling network. A model incorporating spatial dependence and measurement errors with network‐specific biases and variances serves as the basis for the analysis of the combined data from all networks. We develop the associated optimal prediction methodology, which we call complementary co‐kriging because (a) data from each network complements the other, and (b) the solutions to several prediction problems of interest are co‐kriging predictors. A hypothetical example illustrates how much better the complementary co‐kriging predictor can be, when compared to the ordinary kriging predictors from each network alone and to a ‘naive’ combined predictor. We use the methodology to obtain optimal predictions of wet nitrate concentration data over the eastern U.S. using data combined from the National Atmospheric Deposition Program/National Trends Network (NADP/NTN) and the Clean Air Status and Trends Network (CASTNet). Copyright © 2005 John Wiley & Sons, Ltd.
The sharp quantitative isocapacitary inequality

We prove a sharp quantitative form of the classical isocapacitary inequality. Namely, we show that the difference between the capacity of a set and that of a ball with the same volume bounds the square of the Fraenkel asymmetry of the set. This provides a positive answer to a conjecture of Hall, Hayman, and Weitsman (J. d' Analyse Math. '91).
Abelian Spiders

Let Γ be a connected finite graph. Fix an integer k, and let v1, . , vk be k (not necessarily distinct) vertices of Γ. For any k-tuple k = (r1, . . . , rk) of non-negative integers, we define a (k)spider graph Γk on Γ to be the graph obtained by adjoining a 2-valent tree of length ri to Γ at vi. We say a graph Γ is abelian if Q(λ2) is an abelian extension, where λ is the Perron–Frobenius eigenvalue of Γ (the unique largest real eigenvalue of the adjacency matrix MΓ of Γ). If Γ is one of the affine Dynkin diagrams, then Γ is abelian, and λ2 = 4 cos2(2π/N) for some integer N . Conversely, if λ ≤ 2, then Γ is an affine Dynkin diagram.