Miracle-dz/UniFAR-FTUs huggingface dataset:
Homologous Microflares with Mass Ejection and Plasma Heating on the Quiet Sun

Study of microflares on the quiet Sun is extremely important in learning the physics of both solar flare and atmospheric heating. Here, for the first time, we report the detailed observations of two homologous microflares from Atmospheric Imager Assembly (AIA) images and Heliospheric Magnetic Imager magnetograms in a very quiet region. The two microflares are observed clearly in the extreme ultraviolet and faintly in the ultraviolet in AIA images. They have an area of ∼59 Mm2 and ∼46 Mm2, and a duration of 25 minutes and 22 minutes. The magnetic cancellation continuously takes place during the microflares, and the magnetic flux decrease is apparent, with a value of ∼4 × 1018 Mx. The obvious mass ejections are observed during the microflares, and dimming occurs during and after the microflares. The velocity of mass ejection is up to 160 km s−1. For the two microflares, the time of peak intensity in λ 30.4 nm precedes that of the coronal peak emission, up to 2.4–3.3 minutes. Their thermal energy is estimated to be 1.3 × 1027 erg and 2.5 × 1026 erg, respectively, which heats the corona up to 5.8 MK and 2.8 MK. There are many similarities of microflares on the quiet Sun to major flares in the active regions.
A study of the formation of isotopically pure 28Si layers for quantum computers using conventional ion implantation

We have investigated the use of conventional ion implantation to fabricate enriched 28Si layers for use in quantum computers. The final compositions of samples enriched using ultra-low energy (ULE) (800 eV and 2 keV) and low energy (20 keV) 28Si implants of varying fluences (1 × 1016–3.8 × 1017 cm−2) using two different implanters were measured using channelled Rutherford Backscattering Spectroscopy (RBS). The dynamic, binary collision approximation program TRIDYN was used to model the implantation profiles to guide the analysis of the RBS spectra. It was found that ULE implants achieved high 28Si enrichment levels but were heavily contaminated with oxygen due to poor vacuum in the implanter wafer end station. It was shown that oxidation could be reduced by using an accelerator with an end station with better vacuum and increasing the implant energy to 20 keV. However, TRIDYN simulations predict that the best 28Si enrichment levels that could be achieved under these conditions would saturate at ∼99.2% due to self-sputtering. We modelled a range of conditions with TRIDYN and so recommend low energies (<3 keV), ultra-high vacuum implantation for high 28Si enrichment (>99.9%) with the lowest possible fluences (∼5–10 × 1017 cm−2).
1 3 D ec 2 00 0 A Gas-Kinetic Stability Analysis of Self-Gravitating and Collisional Particulate Disks with Application to Saturn ’ s Rings

Linear theory is used to determine the stability of the self-gravitating, rapidly (and nonuniformly) rotating, two-dimensional, and collisional particulate disk against small-amplitude gravity perturbations. A gas-kinetic theory approach is used by exploring the combined system of the Boltzmann and the Poisson equations. The effects of physical collisions between particles are taken into account by using in the Boltzmann kinetic equation a Krook model integral of collisions modified to allow collisions to be inelastic. It is shown that as a direct result of the classical Jeans instability and a secular dissipative-type instability of small-amplitude gravity disturbances (e.g. those produced by a spontaneous perturbation and/or a companion system) the disk is subdivided into numerous irregular ringlets, with size and spacing of the order of 4πρ ≈ 2πh, where ρ ≈ cr/κ is the mean epicyclic radius, cr is the radial dispersion of random velocities of particles, κ is the local epicyclic frequency, and h ≈ 2ρ is the typical thickness of the system. The present research is aimed above all at explaining the origin of various structures in highly flattened, rapidly rotating systems of mutually gravitating particles. In particular, it is suggested that forthcoming Cassini spacecraft high-resolution images may reveal this kind of hyperfine ∼ 2πh < ∼ 100 m structure in the main rings A, B, and C of the Saturnian ring system.
Adsorption of Lead(II) from Aqueous Solution by Using Leaves of Date Trees As an Adsorbent

The efficiency of date tree leaves as a low cost adsorbent for removing lead ions from aqueous solution has been investigated in this paper. Batch experiments were conducted to study the effects of the main parameters such as contact time, initial concentration of Pb(II), adsorbent dose, solution pH, agitation speed, ionic strength, and temperature on the adsorption of Pb(II) by date tree leaves. The maximum removal of lead(II) is found to be 94 % at pH 5.8, initial Pb(II) concentration of 10 mg·L−1, adsorbent dose of 1 g·L−1, agitation speed of 200 rpm, ionic strength of 0.005 M, and temperature of 25 °C. Dynamics of the adsorption process were studied, and the values of rate constants of pseudofirst-order and pseudosecond-order were calculated. Equilibrium isotherms for the adsorption of Pb(II) were analyzed by the Langmuir, Freundlich, and Temkin isotherm models. The Temkin isotherm model was found to represent better the data of Pb(II) sorption onto date tree leaves. Different thermodynamic parameters.
Investigation of sulfur interactions on a conventional nickel-based solid oxide fuel cell anode during methane steam and dry reforming

Solid oxide fuel cells (SOFC) are an attractive energy source because they do not have undesirable emissions, are scalable, and are feedstock flexible, which means they can operate using a variety of fuel mixtures containing H2 and hydrocarbons. In terms of fuel flexibility, most potential fuel sources contain sulfur species, which severely poison the nickel-based anode. The main objective of this thesis is to systematically evaluate sulfur interactions on a conventional Ni/YSZ anode and compare sulfur poisoning during methane steam and dry reforming (SMR and DMR) to a conventional catalyst (Sud Chemie, Ni/K2O−CaAl2O4). Reforming experiments (SMR and DMR) were carried out in a packed bed reactor (PBR), and it was demonstrated that Ni/YSZ is much more sensitive to sulfur poisoning than Ni/K2O−CaAl2O4 as evidenced by the decline in activity to zero in under an hour for both SMR and DMR. Adsorption and desorption of H2S and SO2 on both catalysts was evaluated, and despite the low amount of accessible nickel on Ni/YSZ (14 times lower than Ni/K2O−CaAl2O4), it adsorbs 20 times more H2S and 50 times more SO2 than Ni/K2O−CaAl2O4. A one-dimensional, steady state PBR model (Detchem) was used to evaluate SMR and DMR under poisoning conditions using the Deutschmann mechanism and a recently published sulfur sub-mechanism[1, 2]. To fit the observed deactivation in the presence of 1 ppm H2S, the adsorption/desorption equilibrium constant was increased by a factor 16,000 for Ni/YSZ and 96 for Ni/K2O−CaAl2O4. A tubular SAE reactor was designed and fabricated for evaluating DMR in a reactor that mimics an SOFC. Evidence of hydrogen diffusion through a supposedly impermeable layer indicated that the tubular SAE reactor has a major flaw in which gases diffuse to unintended parts of the tube. It was also found to be extremely susceptible to coking which leads to cell failure even in operating regions that mimic real biogas. These problems made it impossible to validate the tubular SAE model with experimental data, but the tubular SAE model predictions compared with predictions from an existing model agreed well for fuel channel exhaust gases.
Quality and suitability of harvested rainwater for drinking in Bangladesh

Several programs have been undertaken during the last few years to install rooftop rainwater harvesting systems as an alternative drinking water supply source both in the coastal and arsenic affected areas in Bangladesh. In this study, quality of the harvested rainwater used for drinking water supply was assessed. A total of 308 harvested rainwater samples were collected from the different storage reservoirs located both in coastal and arsenic affected areas and analysed for various physical, chemical and microbial indicators. Most of the physical and chemical water quality parameters were well below the Bangladesh Drinking Water Standard and WHO guideline values. However, the harvested rainwater was found microbiologically contaminated to some extent and the water is not suitable for consumption without treatment. For safe and sustainable rainwater harvesting, WHO guideline and water safely plan (WSP) can be adopted in Bangladesh.
Enhanced Ultraviolet Luminescence of ZnO Nanorods Treated by High-Pressure Water Vapor Annealing (HWA)

Zinc oxide nanorods (ZnO NRs), synthesized by a low temperature chemical method, were postannealed at 260 °C in air and under high pressure water vapor (HWA) at 1.3–3.9 MPa. We found that the UV luminescence intensity increased by a factor of 2–3 after HWA annealing compared to that observed after annealing in air. Structural analysis of the nanorods in relation with their optical properties by means of Raman and XPS spectroscopies, transmission and scanning electron microscopies allow to conclude that the origin of the UV luminescence enhancement is due to the transformation of the Zn(OH)2 surface–layer into ZnO, but also to the growth of a new thin ZnO layer at the surface of the rods. This layer is 1–2 nm thick and its presence leads to surface reconstruction of the nanorods. In addition, we show that the size and the density of the nanopores within the ZnO NRs are reduced upon HWA annealing with respect to air annealing.
The influence of felling season and log-soaking temperature on the wetting and phenol formaldehyde adhesive bonding characteristics of birch veneer

Abstract Most adhesive studies employing wood veneer as the substrate assume that it is a relatively uniform material if wood species and veneer thickness are constant. In the present study, veneers from rotary cut birch (Betula pendula Roth) were produced from logs harvested in spring, autumn and winter, and soaked at 20°C and 70°C prior to peeling. Firstly, veneers produced from logs felled in autumn were dried at 103°C for 24 h and subsequently half of these veneers were heat-treated at 180°C for 3 h. In addition, veneers produced from logs felled in all three seasons were dried at 160°C for 3.5 min to simulate industrial drying. The wettability of veneers was evaluated goniometrically, and bonding strength was evaluated with an automated bonding evaluation system (ABES). The results show that soaking birch logs at 70°C rather than at 20°C before peeling, or harvesting trees in the spring rather than in the autumn or winter, gives rise to veneers with enhanced wettability and higher bond strengths with a phenol-formaldehyde adhesive. Changes in the preparation and history of a veneer surface may have a profound effect on the development of adhesive bonds.
α - Maxmin Expected Utility with Non-Unique Prior

Preferences over acts have an α-Maxmin Expected Utility (α-MEU) representation if they can be represented by an α-mix between the worst and the best expected utility over a set or priors. The case α=1 is characterized in Gilboa and Schmeidler (1989). Inspired by their representation result, two novel types of axioms are introduced: α-Monotonicity and α-Uncertainty Attitude. Replacing the axioms Monotonicity and Uncertainty Aversion in Gilboa and Schmeidler (1989) by these axioms provides a characterization of α-MEU preferences for α not 1/2.
Between a Rock and a Hard Place: A New Perspective on the Resource Curse

Military expenditure shares significantly affect the relationship between the risk of civil conflict outbreak and natural resources. We show that a significant positive correlation between the risk of civil conflict outbreak and resource rents is limited to countries with low military expenditure shares. In countries with high military expenditure shares there is no significant relationship between the risk of civil conflict outbreak and rents from natural resources. An important message is thus that a conflict resource curse is absent in countries with sufficiently large military expenditure shares. However, there is a trade-off: the larger military expenditure shares, the smaller is the effect that resource rents have on economic growth and democracy.
On Distributive Justice by Antitrust: The Robin Hood Cartel

Equity concerns in antitrust could justify market power in return for a fairer allocation by weighing the consumer welfare of certain disadvantaged groups more heavily. A simple example of an equity-justified agreement illustrates how seeking distributive justice through relaxed antitrust enforcement is ineffective and inefficient. Permitting competitors to jointly set prices gives them the power to price discriminate, which they could use to redistribute wealth by overcharging the rich and giving lower than competitive prices to the poor. Provided society values redistribution enough, such a ‘Robin Hood cartel’ is profitable, despite losing money on the poor and creating deadweight losses. Yet the poor will be given only what is minimally required in return for permission to take from the rich. Without conditions, the joint-profit maximizing wealth redistribution is nothing more than alms for the poor. They receive more under a full-payout plan, but total deadweight losses remain high. In essence, assigning a larger relative consumer welfare weight to the poor discounts the inefficiencies on the rich.
How do Investors React to Biased Information? Evidence from Chinese IPO Auctions

We study how institutional investors utilize potentially biased information by analyzing the effect of IPO underwriters' earnings forecasts on investors' bidding behaviors in Chinese IPO auctions. Despite the presence of upward biases in underwriters' earnings forecasts, we nd that investors' bid prices are higher in IPOs with higher earnings forecasts. The investors' positive reaction to biased information can be explained in a rational expectation model where the underwriter has valuable information about the IPO but has a biased incentive in presenting the information to investors. Consistent with the model's predictions, we find that an investor's bid price is more sensitive to the underwriter's earnings forecast when the forecast bias is expected to be smaller, when the relative precision of the underwriter's information over the investor's information is higher, and when the investor has a higher valuation of the IPO.
Differential Treatment and the Winner's Effort in Contests with Incomplete Information

We study the design of all-pay contests when the organizer's objective is to maximize the expected winner's effort and contestants have private information about their valuations for the prize. We identify sufficient conditions for every optimal contest to involve differential treatment of ex ante symmetric contestants. Moreover, we provide a complete characterization of optimal contests when valuations are uniformly distributed. Finally, we demonstrate that when differential treatment is allowed, maximizing the expected winner's effort is different from maximizing the expected highest effort, which can be strictly greater in the optimum.
Earnings Management in Australian Not-for-Profit Disability Services

The Australian not-for-profit and charitable sector is an important component in that country’s social capital. It delivers services and supports to some of the most vulnerable people in the community. However, up until recently, poor data sets related to the sector’s financial performance and position have meant that the examination of its financial capacity has been unable to be undertaken. This paper reports on our findings relative to earnings management in the context of Not-for-profit disability service providers. Assessing a longitudinal data set providing financial data relative to 154 such not-for-profits, we have identified that the sector is subject to earnings management, that such activities are aimed at reducing reported profit likely in order for these organisations to meet the normative financial expectations of stakeholders including public sector funders and philanthropists. This finding has significant implications for our understanding of not-for-profit financial, regulatory and audit arrangements in place and accounting standards as they apply to this sector.
Changes in assortative matching and educational inequality: evidence from marriage and birth records in Mexico

Abstract Over the past three decades, educational attainment in Mexico has grown substantially. This increase in educational attainment may affect marriage patterns through the growing supply of individuals with higher education and changing preferences over their partner's education level. We use administrative marriage and birth certificate records to quantify changes in the relative education levels for both married and unmarried couples. Our results suggest that individuals who marry outside their education category prefer to match with a partner with a similar education level. That is, college graduates prefer to match with individuals with a secondary education rather than those with a primary education. We also find that assortativeness among pairs which include college graduates has grown considerably over this time period. Our findings hold across both marriage records and birth certificate records, indicating a parallel increase in assortativeness regardless of marital status.
Reconstructing Cities: Stimulating Redevelopment through the Tax Code

The welfare effect of urban renewal policies depends on the size of the external effects and the quantity of the building stock that gets redeveloped. While evidence on the externalities is growing, credibly identified estimates of the responsiveness of redevelopment are completely lacking. I exploit a sharp reduction in the value-added tax (VAT) on construction services for redevelopment in a select group of 32 Belgian cities to fill this gap. The results show that the 15 percentage points reduction in the VAT rate lead to an increase in the amount of demolished and redeveloped floorspace of respectively 36% and 35%.
ADMM and inexact ALM: the QP case

Embedding randomization procedures in the Alternating Direction Method of Multipliers (ADMM) has recently attracted an increasing amount of interest as a remedy to the fact that the direct $n$-block generalization of ADMM is not necessarily convergent ($n \geq 3$). Even if, in practice, the introduction of such techniques could mitigate the diverging behaviour of the $n$-block extension of ADMM, from the theoretical point of view, it can ensure just the convergence in expectation, which may not be a good indicator of its robustness and efficiency. In this work, analysing the strongly convex quadratic programming case, we interpret the $n$-block Gauss-Seidel sweep performed by ADMM in the context of the inexact Augmented Lagrangian Method. Using the proposed analysis, we are able to outline an alternative technique to those present in literature which, supported from stronger theoretical guarantees, is able to ensure the convergence of the $n$-block generalization of the ADMM method.
Teacher Model Fingerprinting Attacks Against Transfer Learning

Transfer learning has become a common solution to address training data scarcity in practice. It trains a specified student model by reusing or fine-tuning early layers of a well-trained teacher model that is usually publicly available. However, besides utility improvement, the transferred public knowledge also brings potential threats to model confidentiality, and even further raises other security and privacy issues. In this paper, we present the first comprehensive investigation of the teacher model exposure threat in the transfer learning context, aiming to gain a deeper insight into the tension between public knowledge and model confidentiality. To this end, we propose a teacher model fingerprinting attack to infer the origin of a student model, i.e., the teacher model it transfers from. Specifically, we propose a novel optimization-based method to carefully generate queries to probe the student model to realize our attack. Unlike existing model reverse engineering approaches, our proposed fingerprinting method neither relies on fine-grained model outputs, e.g., posteriors, nor auxiliary information of the model architecture or training dataset. We systematically evaluate the effectiveness of our proposed attack. The empirical results demonstrate that our attack can accurately identify the model origin with few probing queries. Moreover, we show that the proposed attack can serve as a stepping stone to facilitating other attacks against machine learning models, such as model stealing.
Stability of combinatorial polynomials and its applications

Many important problems are closely related to the zeros of certain polynomials derived from combinatorial objects. The aim of this paper is to make a systematical study on the stability of polynomials in combinatorics. Applying the characterizations of Borcea and Brändén concerning linear operators preserving stability, we present criteria for real stability and Hurwitz stability of recursive polynomials. We also give a criterion for Hurwitz stability of the Turán expressions of recursive polynomials. As applications of these criteria, we derive some stability results occurred in the literature in a unified manner. In addition, we obtain the Hurwitz stability of Turán expressions for alternating runs polynomials of types A and B and solve a conjecture concerning Hurwitz stability of alternating runs polynomials defined on a dual set of Stirling permutations. Furthermore, we prove that the Hurwitz stability of any symmetric polynomial implies its semi-γ-positivity. We study a class of symmetric polynomials and derive many nice properties including Hurwitz stability, semi-γ-positivity, non γ-positivity, unimodality, strong q-log-convexity, the Jacobi continued fraction expansion and the relation with derivative polynomials. In particular, these properties of the alternating descents polynomials of types A and B can be obtained in a unified approach. Finally, based on the h-polynomials from combinatorial geometry, we use real stability to prove a criterion for zeros interlacing between a polynomial and its reciprocal polynomial, which in particular implies the alternatingly increasing property of the original polynomial. This criterion extends a result of Brändén and Solus and unifies such properties for many combinatorial polynomials, including ascent polynomials for k-ary words, descent polynomials on signed Stirling permutations and colored permutations and q-analog of descent polynomials on colored permutations, and so on. Furthermore, we also obtain a recurrence relation and zeros interlacing of q-analog of descent polynomials on colored permutations that extend some results of Brändén and Brenti. In addition, as an application of Hurwitz stability, we prove the alternatingly increasing property and zeros interlacing for two kinds of peak polynomials on the dual set of Stirling permutations. ∗Supported partially by the National Natural Science Foundation of China (Nos. 11971206, 12022105) and the Natural Science Fund for Distinguished Young Scholars of Jiangsu Province (No. BK20200048). Email address: ding-mj@hotmail.com (M.-J. Ding), bxzhu@jsnu.edu. cn (B.-X. Zhu)