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Timing and Spectral Analysis of the Black Hole X-Ray Binary MAXI J1803-298 with Insight-HXMT Data

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Research in Astronomy and Astrophysics 2024年第6期24卷 209-224页

作者： Ying-Chen Xu Jin-Lu Qu MMéndez Rui-Can Ma Long Ji Liang Zhang Yue Huang Qing-Cui Bu Li-Ming Song Key Laboratory of Particle Astrophysics Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China University of Chinese Academy of Sciences Chinese Academy of SciencesBeijing 100049China Kapteyn Astronomical Institute University of GroningenP.O.BOX 8009700 AV GroningenThe Netherlands Dongguan Neutron Science Center Dongguan 523808China School of Physics and Astronomy Sun Yat-Sen UniversityZhuhai 519082China Institut für Astronomie und Astrophysik Kepler Center for Astro and Particle PhysicsEberhard Karls UniversitätSand 1D-72076 TübingenGermany

We present a comprehensive analysis of the 2021 outburst of MAXI J1803–298 utilizing observations of the Insight-Hard X-ray Modulation Telescope(Insight-HXMT)spanning from the low hard state to the high soft *** the Insight-HXMT data set,compared to the previous work,we identify a more prolonged presence of typeC quasi-periodic oscillations(QPOs)with centroid frequencies ranging from~0.16 to 6.3 Hz,which present correlations with the hardness ratio and the photon index of the Comptonized *** QPO frequencies less than~2 Hz,the QPO phase lags are hard(photons of 10–19 keV arrive later than those of 1–4 keV),while at higher frequencies,the lags become soft at and above~4 ***,the spectra in all Insight-HXMT observations consist of a multi-color blackbody component and a Comptonized component,as commonly observed in classical black hole X-ray *** analyze state transitions and the evolution of accretion geometry in this *** fitted inner disk radius increases abnormally during the low hard state,hypothesized to result from the corona condensing onto the inner ***,two significant drops in flux are observed during the soft intermediate state,maybe implying changes in the corona/jet and the disk,respectively.

关键词： X-rays:binaries accretion accretion disks stars:black holes

Calculation of Two-Tailed Exact Probability in the Wald-Wolfowitz One-Sample Runs Test

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Journal of Data Analysis and Information Processing 2024年第1期12卷 89-114页

作者： josé Moral De La Rubia School of Psychology Universidad Autónoma de Nuevo León Monterrey Nuevo León México

The objectives of this paper are to demonstrate the algorithms employed by three statistical software programs (R, Real Statistics using Excel, and SPSS) for calculating the exact two-tailed probability of the Wald-Wolfowitz one-sample runs test for randomness, to present a novel approach for computing this probability, and to compare the four procedures by generating samples of 10 and 11 data points, varying the parameters n0 (number of zeros) and n1 (number of ones), as well as the number of runs. Fifty-nine samples are created to replicate the behavior of the distribution of the number of runs with 10 and 11 data points. The exact two-tailed probabilities for the four procedures were compared using Friedman’s test. Given the significant difference in central tendency, post-hoc comparisons were conducted using Conover’s test with Benjamini-Yekutielli correction. It is concluded that the procedures of Real Statistics using Excel and R exhibit some inadequacies in the calculation of the exact two-tailed probability, whereas the new proposal and the SPSS procedure are deemed more suitable. The proposed robust algorithm has a more transparent rationale than the SPSS one, albeit being somewhat more conservative. We recommend its implementation for this test and its application to others, such as the binomial and sign test.

关键词： Randomness Nonparametric Test Exact Probability Small Samples Quantiles

Utilizing neural networks to supplant chemical kinetics tabulation through mass conservation and weighting of species depletion

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Energy and AI 2024年第2期16卷 101-110页

作者： Franz M.Rohrhofer Stefan Posch Clemens Gößnitzer joséM.García-Oliver Bernhard C.Geiger Know-Center GmbH Sandgasse 36Graz8010StyriaAustria LEC GmbH Inffeldgasse 19Graz8010StyriaAustria Universitat Politècnica de València Camíde VeraValència46022ValènciaSpain

Artificial Neural Networks(ANNs)have emerged as a powerful tool in combustion simulations to replace memory-intensive tabulation of integrated chemical *** reaction mechanisms,however,present a challenge for standard ANN approaches as modeling multiple species typically suffers from inaccurate predictions on minor *** paper presents a novel ANN approach which can be applied on complex reaction mechanisms in tabular data form,and only involves training a single ANN for a complete reaction *** approach incorporates a network architecture that automatically conserves mass and employs a particular loss weighting based on species *** modifications are used to improve the overall ANN performance and individual prediction accuracies,especially for minor species mass *** validate its effectiveness,the approach is compared to standard ANNs in terms of performance and ANN *** distinct reaction mechanisms(H_(2),C_(7)H_(16),C_(12)H_(26),OME_(34))are used as a test cases,and results demonstrate that considerable improvements can be achieved by applying both modifications.

关键词： Neural network approach Chemical kinetics Flamelet tabulation Mass conservation Species loss weighting

Rice University Rule to Determine the Number of Bins

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Open Journal of Statistics 2024年第1期14卷 119-149页

作者： josé Moral De La Rubia School of Psychology Universidad Autónoma de Nuevo León Monterrey Mexico

This study aims to establish a rationale for the Rice University rule in determining the number of bins in a histogram. It is grounded in the Scott and Freedman-Diaconis rules. Additionally, the accuracy of the empirical histogram in reproducing the shape of the distribution is assessed with respect to three factors: the rule for determining the number of bins (square root, Sturges, Doane, Scott, Freedman-Diaconis, and Rice University), sample size, and distribution type. Three measures are utilized: the average distance between empirical and theoretical histograms, the level of recognition by an expert judge, and the accuracy index, which is composed of the two aforementioned measures. Mean comparisons are conducted with aligned rank transformation analysis of variance for three fixed-effects factors: sample size (20, 35, 50, 100, 200, 500, and 1000), distribution type (10 types), and empirical rule to determine the number of bins (6 rules). From the accuracy index, Rice’s rule improves with increasing sample size and is independent of distribution type. It outperforms the Friedman-Diaconis rule but falls short of Scott’s rule, except with the arcsine distribution. Its profile of means resembles the square root rule concerning distributions and Doane’s rule concerning sample sizes. These profiles differ from those of the Scott and Friedman-Diaconis rules, which resemble each other. Among the seven rules, Scott’s rule stands out in terms of accuracy, except for the arcsine distribution, and the square root rule is the least accurate.

关键词： Histogram Class Intervals Accuracy Distributions Descriptive Statistics

Measures of Variability for Qualitative Variables Using the R Software

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Open Journal of Statistics 2024年第3期14卷 259-293页

作者： josé Moral de la Rubia School of Psychology Universidad Autnoma de Nuevo Len Monterrey Mexico

Although there are many measures of variability for qualitative variables, they are little used in social research, nor are they included in statistical software. The aim of this article is to present six measures of variation for qualitative variables of simple calculation, as well as to facilitate their use by means of the R software. The measures considered are, on the one hand, Freemans variation ratio, Morals universal variation ratio, Kvalseths standard deviation from the mode, and Wilcoxs variation ratio which are most affected by proximity to a constant random variable, where the measures of variability for qualitative variables reach their minimum value of 0. On the other hand, the Gibbs-Poston index of qualitative variation and Shannons relative entropy are included, which are more affected by the proximity to a uniform distribution, where the measures of variability for qualitative variables reach their maximum value of 1. Point and interval estimation are addressed. Bootstrap by the percentile and bias-corrected and accelerated percentile methods are used to obtain confidence intervals. Two calculation situations are presented: with a sample mode and with two or more modes. The standard deviation from the mode among the six considered measures, and the universal variation ratio among the three variation ratios, are particularly recommended for use.

关键词： Variation Ratio Relative Entropy Index of Qualitative Variation Standard Deviation from Mode Bootstrap Confidence Interval

Sodium-glucose cotransporter-2 inhibitors protect tissues via cellular and mitochondrial pathways:Experimental and clinical evidence

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World Journal of Experimental Medicine 2024年第2期14卷 46-52页

作者： Raúl Lelio Sanz Sebastián García Menéndez Felipe Inserra Leon Ferder Walter Manucha Department of Pathology Facultad de Ciencias MédicasUniversidad Nacional de CuyoMendoza 5500Argentina Department of Pharmacology Instituto de Medicina y Biología Experimental de CuyoCentro Científico TecnológicoMendoza 5500Argentina Department of Nephrology Universidad de MaimónidesCiudad Autónoma de Buenos Aires C1405Argentina Department of Cardiology Universidad de MaimónidesCiudad Autónoma de Buenos Aires C1405Argentina

Mitochondrial dysfunction is a key driver of cardiovascular disease(CVD)in metabolic syndrome and *** dysfunction promotes the production of reactive oxygen species(ROS),which cause oxidative stress and *** II,the main mediator of the renin-angiotensin-aldosterone system,also contributes to CVD by promoting ROS *** activity of sirtuins(SIRTs),a family of proteins that regulate cellular metabolism,also worsens oxidative *** of energy production by mitochondria is a common feature of all metabolic *** SIRT levels and 5’adenosine monophosphate-activated protein kinase signaling stimulate hypoxia-inducible factor 1 beta,which promotes ***,in turn,increases autophagy and mitophagy,processes that clear cells of debris and protect against *** cotransporter-2 inhibitors(SGLT2i),a class of drugs used to treat type 2 diabetes,have a beneficial effect on these *** clinical trials have shown that SGLT2i improves cardiac function and reduces the rate of cardiovascular and renal ***2i also increase mitochondrial efficiency,reduce oxidative stress and inflammation,and strengthen *** findings suggest that SGLT2i hold great potential for the treatment of ***,they are proposed as anti-aging drugs;however,rigorous research is needed to validate these preliminary findings.

关键词： Sodium-glucose cotransporter-2 inhibitors Cardiovascular diseases Sirtuins Oxidative stress Inflammation Mitochondrial dysfunction

Hydroxyapatite composites with carbon allotropes:Preparation,properties,and applications

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Particuology 2024年第5期88卷 239-265页

作者： Boris I.Kharisov Oxana V.Kharissova Lucy T.González Yolanda Peña Méndez Igor E.Uflyand Idalia Gómez de la Fuente Universidad Autónoma de Nuevo León Ave.UniversidadCiudad UniversitariaSan Nicolás de los GarzaNuevo León 66455Mexico Tecnologico de Monterrey Escuela de Ingeniería y CienciasMonterreyNuevo Leon 64890Mexico Department of Chemistry Southern Federal UniversityRostov-on-DonRussia

Hydroxyapatite(HA)and its composites with inorganic additives,dopants,and polymers is a rapidly developing branch in the materials *** particular,carbon allotropes are widely used in these composites being widely applied for medical *** a gap of insufficient generalization of recent achievements in the field of the HA/Carbon composites,in this review we present the state of the art of the field of HA composites and hybrids with classic carbon allotropes and *** composites are known for carbon nanotubes,nanofibers,graphene and its oxidized forms,as well as,in a lesser grade,for graphite,fullerenes,nanodiamonds,carbon nanofoams,*** composites can be fabricated by a variety of classic and less-common methods,such as co-precipitation(with or without ultrasonic treatment),CVD,hot isostatic pressing,hydrothermal,spark plasma sintering,biomimetic mineralization,thermal and plasma spray,electrochemical and electrophoretic deposition,self-assembling,3D printing,electrospinning,and lyophilisation,among *** of various synthesis techniques can be also carried out for composite *** or synthetic HA can be used as it is for further interaction with carbon allotropes or it can be first prepared and then reacted with carbon counterpart;similarly,carbon allotropes can be introduced into the interaction with HA directly or they can be first synthesized,in particular from *** biocompatible composites can be produced in the form of coatings,powders,and scaffolds and can additionally contain quantitative amounts of third phases,frequently natural or synthetic *** these composites,especially with O-containing functionalizing groups,HA disadvantages could be considerably decreased with simultaneous enhancement of mechanical properties,becoming similar to human bone,chemical stability and biocompatibility,as well as possessing antibacterial ***→G reduction and higher HA decoration were obs

关键词： Hydroxyapatite Carbon nanotubes Graphene Quantum dots Fullerenes Nanodiamonds

The first record of dermochelyid turtles in the Eocene of Tierra del Fuego:new insights on the evolution of the Weddellian faunas

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Advances in Polar Science 2024年第1期35卷 63-77页

作者： Paula BONA Juliana STERLI Marcelo Saúl de la FUENTE Eduardo OLIVERO Marta S.FERNÁndez Marcelo REGUERO División Paleontología Vertebrados Museo de La Plata-Anexo IIFacultad de Ciencias Naturales y MuseoUniversidad Nacional de La PlataLa Plata B1900FWAArgentina Consejo Nacional de Investigaciones Científicas y Técnicas(CONICET) Ciudad Autónoma de Buenos Aires C1425FQBArgentina Museo Paleontológico Egidio Feruglio Trelew U9100Argentina Instituto de Evolución Ecología Histórica y Ambiente-CONICETSan Rafael CP5600Argentina Centro Austral de Investigaciones Científicas-CONICET Universidad Nacional de Tierra del FuegoUshuaia CP 9410Argentina División Paleontología Vertebrados Museo de La PlataUniversidad Nacional de La PlataLa Plata B1900FWAArgentina

The Antarctic Paleogene marine fossil record has been the key to reconstructing the evolution of the Weddellian Sea and final dismemberment of Southern *** this context,Eocene marine vertebrates from Seymour(Marambio)Island have provided valuable *** present the first Eocene record of marine reptiles from the southern Atlantic Coast of South *** corresponds to several postcranial turtle remains represented by a proximal end of the right humerus,three caudal and one thoracic vertebrae,a fragment of the left pubis,and ten ossicles of the dorsal carapace,coming from the Leticia Formation(late-mid Eocene)at Cabo Tiburones,Tierra del Fuego,*** materials show severalfeatures such as the size and general morphology of the humerus and vertebrae,and the presence of relatively small,irregular,smooth,and unkeeled ossicles,which allow us to assign them to Dermochelyidae *** are a cosmopolitan group ofcryptodiran turtles,registered from the late Cretaceous up to the recent,with some physiological-biological peculiarities(e.g.,endothermy and an exclusive jellyfish-based diet)and characterized by the presence of an osseous carapace formed by *** new finding from the Leticia Formation is an addition to the scarce and extremely fragmentary record of Eocene dermochelyids from the southern seas like those from the La Meseta and Submeseta formations(Antarctica)and the Waihao and Burnside formations(New Zealand).This new information allows us to discuss the presence of these turtles in such high latitudes in the past and its implication in the evolution of the Weddellian fauna.

关键词： marine reptiles sea turtles Dermochelyidae Paleogene La Meseta Formation Submeseta Formation Leticia Formation

Tribologically induced nanostructural evolution of carbon materials: A new perspective

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Friction 2024年第1期12卷 144-163页

作者： Guilherme Oliveira NEVES Nicolás ARAYA Diego Berti SALVARO Thiago de Souza LAMIM Renan Oss GIACOMELLI Cristiano BINDER Aloisio Nelmo KLEIN joséDaniel Biasoli de MELLO Laboratório de Materiais Universidade Federal de Santa CatarinaSanta Catarina 88040-900Brazil Departamento de Ingeniería Mecánica Facultad de IngenieríaUniversidad del Bío-BíoConcepcion 4070-386Chile Universidad de Concepción Concepcion 4070-386Chile SENAI Innovation Institute for Laser Processing Santa Catarina 89218-153Brazil Universidade Federal de Uberlândia Minas Gerais 38408-100Brazil

Carbon-based solid lubricants are excellent options to reduce friction and wear,especially with the carbon capability to adopt different allotropes *** the macroscale,these materials are sheared on the contact along with debris and contaminants to form tribolayers that govern the tribosystem *** a recently developed advanced Raman analysis on the tribolayers,it was possible to quantify the contactinduced defects in the crystalline structure of a wide range of allotropes of carbon-based solid lubricants,from graphite and carbide-derived carbon particles to multi-layer graphene and carbon *** addition,these materials were tested under various dry sliding conditions,with different geometries,topographies,and solid-lubricant application *** of the initial tribosystem conditions and allotrope level of atomic ordering,there is a remarkable trend of increasing the point and line defects density until a specific saturation limit in the same order of magnitude for all the materials tested.

关键词： carbon nanostructures tribology Raman spectroscopy defects quantification tribolayer solid lubrication