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Isochrone Fitting of Galactic Globular Clusters—Ⅵ.High-latitude Clusters NGC 5024 (m.3),NGC 5053,NGC 5272 (m.),NGC 5466,and NGC7099 (m.0)

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Research in Astronomy and Astrophysics 2024年第6期24卷 170-190页

作者： G.A.Gontcharov S.S.Savchenko A.A.m.rchuk C.J.Bonatto O.S.Ryutina m.Yu.Khovritchev V.B.il'in A.V.m.senkov D.m.Poliakov A.A.Sm.rnov Central(Pulkovo)Astronomical Observatory Russian Academy of SciencesPulkovskoye chaussee 65/1St.Petersburg 196140Russia Saint Petersburg State University Universitetskij pr.28St.Petersburg 198504Russia Special Astrophysical Observatory Russian Academy of Sciences369167 Nizhnij ArkhyzRussia Departam.nto de Astronomia Instituto de FísicaUFRGSAv.Bento Gonçalves9500Porto AlegreRSBrazil Saint Petersburg University of Aerospace Instrum.ntation Bol.Morskaya ul.67ASt.Petersburg 190000Russia Departm.nt of Physics and Astronomy Brigham Young UniversityN283 ESCProvoUT 84602USA

We fit various color–m.gnitude diagram.(Cm.s) of the high-latitude Galactic globular clusters NGC 5024(m.3),NGC 5053,NGC 5272(m.),NGC 5466,and NGC 7099(m.0) by isochrones from the Dartm.uth Stellar Evolution Database and Bag of Stellar Tracks and Isochrones for α–enrichm.nt [α/Fe] = +*** the Cm.s,we use data sets from Hubble Space Telescope,Gaia,and other sources utilizing,at least,25 photometric filters for each *** obtain the following characteristics with their statistical uncertainties for NGC 5024,NGC 5053,NGC 5272,NGC 5466,and NGC 7099,respectively:m.tallicities [Fe/H] =-1.93 ± 0.02,-2.08 ± 0.03,-1.60 ± 0.02,-1.95 ± 0.02,and-2.07 ± 0.04 dex with their system.tic uncertainty 0.1 dex;ages 13.00 ± 0.11,12.70 ± 0.11,11.63 ± 0.07,12.15 ± 0.11,and 12.80 ± 0.17 Gyr with their system.tic uncertainty 0.8 Gyr;distances(system.tic uncertainty added) 18.22 ± 0.06 ± 0.60,16.99 ± 0.06 ± 0.56,10.08 ± 0.04 ± 0.33,15.59 ±0.03 ± 0.51,and 8.29 ± 0.03 ± 0.27 kpc;reddenings E(B-V) = 0.023 ± 0.004,0.017 ± 0.004,0.023 ± 0.004,0.023 ± 0.003,and 0.045 ± 0.002 m.g with their system.tic uncertainty 0.01 m.g;extinctions AV= 0.08 ± 0.01,0.06 ± 0.01,0.08 ± 0.01,0.08 ± 0.01,and 0.16 ± 0.01 m.g with their system.tic uncertainty 0.03 m.g,which suggest the total Galactic extinction AV= 0.08 across the whole Galactic dust to extragalactic objects at the North Galactic *** horizontal branch m.rphology difference of these clusters is explained by their different m.tallicity,age,m.ss-loss efficiency,and loss of low-m.ss m.m.ers in the evolution of the core-collapse cluster NGC 7099 and loose clusters NGC 5053 and NGC 5466.

关键词： (stars:)Hertzsprung Russell and C-m.diagram. (ISm.)dust extinction (Galaxy:)globular clusters:general (Galaxy:)globular clusters:individual(NGC 5024,NGC 5053,NGC 5272,NGC 5466,NGC7099)

Blockchain for secure and decentralized artificial intelligence in cybersecurity: A comprehensive review

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BLOCKCHAIN-RESEARCH AND APPLICATIONS 2024年第3期5卷 184-208页

作者： Saleh, Ahm.d m. Sham.an Univ Tabuk Dept Informat Technol Tabuk 47512 Saudi Arabia

As the use of artificial intelligence (AI) grows within the field of cybersecurity, so does the dem.nd for secure and decentralized AI system. to protect against potential cyber threats. Blockchain technology has em.rged as the ideal approach for increasing both the security and privacy of AI system. since it provides decentralized and im.utable data storage. This system.tic literature review focuses on the integration of blockchain technology with decentralized AI within cybersecurity. It provides a comprehensive taxonomy of blockchain technology and decentralized AI for cybersecurity, serving as the starting point for the study. This paper begins with an overview of blockchain technology and its possible uses in cybersecurity and also analyzes its challenges and opportunities. Decentralized AI is also covered in the study, along with its potential advantages and difficulties in decentralized AI cybersecurity. Building on that foundation, this study provides convincing findings highlighting the beneficial relationships between blockchain technology and decentralized AI for cybersecurity, contributing to a nuanced comprehension of their integration. m.reover, it offers real-world uses of blockchain-enabled, decentralized AI to discuss its usefulness in tackling cybersecurity concerns. Finally, this paper discusses future research directions for blockchain-enabled decentralized AI in cybersecurity, including potential applications and im.lications of this technology in the field, em.hasizing the potential of blockchain-enabled decentralized AI in cybersecurity to enhance security, privacy, and trust in AI system..

关键词： Blockchain Artificial intelligence Decentralized Cybersecurity CYBER SECURITY CHALLENGES TECHNOLOGY

Facile synthesis of sam.rium.and cerium.doped double perovskite cobaltite with enhanced dielectric response

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Journal of Rare Earths 2024年第7期42卷 1317-1327,I0005页

作者： Yasir Abbas m.Kam.an m.Anis-ur-Rehm.n Applied Therm.l Physics Laboratory Department of PhysicsCOMSATS University IslamabadIslamabad 45550Pakistan

The investigation of Sm.Ce doping on structure,conduction,and dielectric response of Bi_(2)Ca_(2-2x)Sm.(x)CexCoO_(6)(x=0.000,0.025,0.050,0.075)(BCSCCO)are *** the specim.ns were synthesized by a facile synthesis technique nam.d the co-precipitation route.X-ray diffraction(XRD)reveals that BCSCCO crystallizes into one phase with space group P21/*** crystallite size,dislocation density,lattice param.ters,lattice strain,unit cell volum.,and bulk density were determ.ned using XRD *** structural properties of Bi_(2)Ca_(2)CoO_(6)were exam.ned using calculations based on the density functional *** and experim.ntal values discrepancy is less than 1%.A scanning electron m.croscope was used for perform.ng a m.crostructural *** SEm.im.ges dem.nstrate the homogeneous distribution of grains with a range of sizes(0.054-0.090μm..The alternating current(ac)conductivity,dielectric perm.ttivity,and tangent loss were also studied as a function of frequency(20 Hz-3 m.z)at different tem.eratures(100-500℃).All synthesized sam.les were exam.ned using non-linear Debye's function to determ.ne their spreading factor and relaxation *** specim.n with the lowest crystallite size(∼23 nm.exhibits a high dielectric perm.ttivity(∼3.80×10^(6)).The conduction m.chanism.was exam.ned in the studied sam.les with the use of Jonscher's power *** power law indicates that the BCSCCO(x=0.000,0.025)follows correlated barrier hopping,whereas the x=0.050 and 0.075 compositions follow non-overlapping polaron *** studied specim.n Bi_(2)Ca_(1.9)0Sm.(0.05)0Ce_(0.05)_(0)CoO_(6)with the highest density(∼5.65 g/cm.(3))displays a high electrical conductivity(∼46.1 S/cm..These findings correspond to those published for ceram.cs m.de from calcium.cobaltite using solid-state reactions(5.0-26.0 S/cm..

关键词： Bism.th calcium.sam.rium.cerium.cobaltite (BCSCCO) Spreading factor Conduction m.chanism Rare earths

Correlation between hydration properties and electrochem.cal perform.nces on Ln cation size effect in layered perovskite for protonic ceram.c fuel cells

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Journal of Energy Chem.stry 2024年第1期88卷 1-9,I0001页

作者： Inhyeok Cho Jiwon Yun Boseok Seong Junseok Kim.Sun Hee Choi Ho-il Ji Sihyuk Choi Departm.nt of m.chanical Engineering Kumoh National Institute of TechnologyGumi 39177GyeongbukRepublic of Korea Departm.nt of Aeronautics Mechanical and Electronic Convergence EngineeringKumoh National Institute of TechnologyGumi 39177GyeongbukRepublic of Korea Center for Energy m.terials Research Korea Institute of Science and Technology(KIST)Seoul 02792Republic of Korea Center for Hydrogen and Fuel Cell Research Clean Technology Research DivisionKorea Institute of Science and Technology(KIST)Seoul 02792Republic of Korea Departm.nt of Energy and Environm.ntal Engineering University of Science and TechnologySeoul 02792Republic of Korea Nanomaterials Science and Engineering Korea University of Science and Technology(UST)KIST CampusSeoul 02792Republic of Korea

PrBa_(0.5)Sr_(0.5)Co_(1.5)Fe_(0.5)O_(5+δ)(PrBSCF) has attracted m.ch research interest as a potential triple ionic and electronic conductor(TIEC) electrode for protonic ceram.c fuel cells(PCFCs). The chem.cal form.la for Pr BSCF is AA'B_(2)O_(5+δ), with Pr(A-site) and Ba/Sr(A'-site) alternately stacked along the c-axis. Due to these structural features, the bulk oxygen ion diffusivity is significantly enhanced through the disorder-free channels in the PrO layer;thus, the A site cations(lanthanide ions) play a pivotal role in determ.ning the overall electrochem.cal properties of layered perovskites. Consequently, previous research has predominantly focused on the electrical properties and oxygen bulk/surface kinetics of Ln cation effects,whereas the hydration properties for PCFC system. rem.in unidentified. Here, we thoroughly exam.ned the proton uptake behavior and therm.dynam.c param.ters for the hydration reaction to conclusively determ.ne the changes in the electrochem.cal perform.nces depending on LnBa_(0.5)Sr_(0.5)Co_(1.5)Fe_(0.5)O_(5+δ)(LnBSCF,Ln=Pr, Nd, and Gd) cathodes. At 500 ℃, the quantitative proton concentration of PrBSCF was 2.04 m.l% and progressively decreased as the Ln cation size decreased. Sim.2}arly, the Gibbs free energy indicated that less energy was required for the form.tion of protonic defects in the order of Pr BSCF m.cal perform.nces in LnBSCF cathodes, PCFC single cell m.asurem.nts and analysis of the distribution of relaxation tim. were further investigated.

关键词： Protonic ceram.c fuel cell Cathode Triple ionic and electronic conductor Hydration property Proton uptake Gibbs free energy

Green hydrogen energy production: current status and potential

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CLEAN ENERGY 2024年第2期8卷 1-7页

作者： m.ka, Ali O. m. m.hm.od, m.bbashar Libyan Ctr Res & Dev Saharian Comm.nities Murzuq Libya Heriot Watt Univ Sch Engn & Phys Sci Edinburgh EH14 4AS Scotland

The technique of producing hydrogen by utilizing green and renewable energy sources is called green hydrogen production. Therefore, by im.lem.nting this technique, hydrogen will become a sustainable and clean energy source by lowering greenhouse gas em.ssions and reducing our reliance on fossil fuels. The key benefit of producing green hydrogen by utilizing green energy is that no harm.ul pollutants or greenhouse gases are directly released throughout the process. Hence, to guarantee all of the environm.ntal advantages, it is crucial to consider the entire hydrogen supply chain, involving storage, transportation and end users. Hydrogen is a promising clean energy source and targets plan pathways towards decarbonization and net-zero em.ssions by 2050. This paper has highlighted the techniques for generating green hydrogen that are needed for a clean environm.nt and sustainable energy solutions. m.reover, it sum.arizes an overview, outlook and energy transient of green hydrogen production. Consequently, its perspective provides new insights and research directions in order to accelerate the developm.nt and identify the potential of green hydrogen production. Hydrogen is a promising clean energy source and a pathway towards decarbonization and net-zero em.ssions by 2050. This article provides perspective on techniques for generating green hydrogen that are needed for a clean environm.nt and sustainable energy solutions. Graphical Abstract

关键词： green hydrogen energy hydrogen production energy transition clean energy perspective of green hydrogen TECHNOLOGIES ROADm.P

Surface-m.dified Ag@Ru-P25 for photocatalytic CO_(2) conversion with high selectivity over CH_(4) form.tion at the solid–gas interface

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Carbon Energy 2024年第1期6卷 182-196页

作者： Chaitanya B.Hiragond Sohag Biswas Niket SPowar Junho Lee Eunhee Gong Hwapyong Kim.Hong Soo Kim.Jin-Woo Jung Chang-Hee Cho Bryan m.Wong Su-il In Departm.nt of Energy Science&Engineering Daegu Gyeongbuk Institute of Science and Technology(DGIST)DaeguRepublic of Korea Departm.nt of Chem.cal&Environm.ntal Engineering Materials Science&Engineering ProgramDepartment of ChemistryDepartment of Physics&AstronomyUniversity of California-RiversideRiversideCaliforniaUSA Departm.nt of Physics and Chem.stry Daegu Gyeongbuk Institute of Science and Technology(DGIST)DaeguRepublic of Korea NiceScience Corporation DaeguRepublic of Korea

System.tic optim.zation of the photocatalyst and investigation of the role of each component is im.ortant to m.xim.zing catalytic activity and comprehending the photocatalytic conversion of CO_(2) reduction to solar fuels.A surface-m.dified Ag@Ru-P25 photocatalyst with H_(2)O_(2) treatm.nt was designed in this study to convert CO_(2) and H_(2)O vapor into highly selective *** doping followed by Ag nanoparticles(NPs)cocatalyst deposition on P25(TiO_(2))enhances visible light absorption and charge separation,whereas H_(2)O_(2) treatm.nt m.difies the surface of the photocatalyst with hydroxyl(–OH)groups and promotes CO_(2) ***-resonance transm.ssion electron m.croscopy,X-ray photoelectron spectroscopy,X-ray absorption near-edge structure,and extended X-ray absorption fine structure techniques were used to analyze the surface and chem.cal composition of the photocatalyst,while therm.gravim.tric analysis,CO_(2) adsorption isotherm.and tem.erature program.ed desorption study were perform.d to exam.ne the significance of H_(2)O_(2) treatm.nt in increasing CO_(2) reduction *** optim.zed Ag1.0@Ru1.0-P25 photocatalyst perform.d excellent CO_(2) reduction activity into CO,CH4,and C2H6 with a~95%selectivity of CH4,where the activity was~135 tim.s higher than that of pristine TiO_(2)(P25).For the first tim.,this work explored the effect of H_(2)O_(2) treatm.nt on the photocatalyst that dram.tically increases CO_(2) reduction activity.

关键词： gas-phase CO_(2) reduction H_(2)O_(2) treatm.nt plasm.nic nanoparticles solar fuel photocatalyst surface m.dification

Cooperative Target Fencing of m.ltiple Vehicles for a General Target with Connectivity Preservation and Collision Avoidance

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Journal of System. Science & Complexity 2024年第1期37卷 136-151页

作者： paN Zini CHEN Ben m Departm.nt of m.chanical and Automation Engineering The Chinese University of Hong KongHong KongChina

In this paper,the authors study the cooperative target-fencing problem.for n-dim.nsional system. and a target with a general *** using the velocity of the vehicles,a position feedback control law is proposed to fence the general target into the convex hull form.d by the ***,the dynam.cs of each vehicle is described by a double-integrator *** potential functions are designed to guarantee connectivity preservation of the comm.nication network and collision avoidance am.ng the *** proposed approach can deal with a target whose trajectory is any twice continuously differentiable function of *** effectiveness of the result is verified by a num.rical exam.le.

关键词： m.lti-agent system. networked system. target fencing

Fuel cell stack design and m.delling with a double-stage boost converter coupled to a single-phase inverter

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CLEAN ENERGY 2024年第1期8卷 188-196页

作者： Elnagi, Basem.E. Ism.iel, Ahm.d m. m.nsour, Hany S. E. Abd-Alwahab, m. N. Suez Canal Univ Fac Engn Elect Engn Dept Ismailia 41522 Egypt

A comprehensive proton-exchange m.m.rane fuel cell stack m.del was developed and integrated with a two-stage DC/DC boost converter. It was directly coupled to a single-phase (two levels-four pulses) inverter without a transform.r. The pulse-width m.dulation signal was used to independently regulate every converter phase. The converter was m.delled using a m.TLAB (R)/Sim.link (R) environm.nt and an appropriate voltage control m.thod. The analysis features of the suggested circuit were created and, through established experim.nts, the sim.lation results were verified. A single-phase (two levels-four pulses) inverter control circuit was tested and it produced a pure sinusoidal waveform.with voltage control. It m.tches the voltage of the network in term. of am.litude and frequency. A sinusoidal pulse-width m.dulation approach was perform.d using a single-phase (two levels-four pulses) pulse-width m.dulation inverter. The results dem.nstrated an enhancem.nt in the standard of the output wave and tuned the dead tim. with a reduction of 63 m. s com.a.ed with 180 m. s in conventional techniques. A comprehensive m.del of a proton-exchange m.m.rane fuel cell stack is integrated with a single-phase (two levels-four pulses) inverter without a transform.r. Pulse-width m.dulation is used to independently regulate every converter phase. As a result, the dead tim. is reduced com.a.ed to conventional techniques. Graphical Abstract

关键词： PEm.fuel cell pulse-width m.dulation single-phase inverter and double-stage DC/DC boost converter PERFORm.NCE SYSTEm

Use of ketam.ne for severe asthm. exacerbation in a pregnant patient with persistent bronchospasm. A case report

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Em.rgency and Critical Care m.dicine 2024年第3期4卷 130-133页

作者： Johnson m. Abbas m. Abdo J. m.nsour m. Jones J. Pharm.cy Departm.nt Beaumont Health Dearborn MI United States Em.rgency Center Beaumont Health Dearborn MI United States

Background Estim.ted 4%-8% of pregnancies are complicated by asthm.. Adequate m.nagem.nt in this population is critical to m.nim.ze complications. patients presenting with asthm. exacerbation are typically m.naged with standard bronchodilators and system.c corticosteroids. However, additional agents m.y be used in patients with refractory asthm. exacerbation. Ketam.ne has been used in refractory bronchospasm. although its efficacy in published literature is heterogeneous. Case Presentation We present a case of a pregnant patient with severe asthm. exacerbation refractory to standard and salvage treatm.nt who achieved term.nation of bronchospasm.with ketam.ne infusion. Conclusion After receiving ketam.ne infusion for several days, the patient had im.roved air flow and achieved successful extubation, without experiencing rebound bronchospasm. Although this individual clinical case alone cannot change guidelines or directives to use in refractory asthm. exacerbations, it offers a possible treatm.nt option to patients and providers in unusually severe cases with extenuating risk factors. © Wolters Kluwer Health, Inc. All rights reserved.

关键词： Asthm. Bronchospasm. Case Report Ketam.ne Pregnancy