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Critical behavior and Joule-Thomson expansion of charged AdS black holes surrounded by exotic fluid with modified Chaplygin equation of state

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Chinese Physics C 2024年第6期48卷 179-190页

作者：张梦瑶陈浩 Hassan Hassanabad 隆正文杨辉 School of Mathematics and Statistics Guizhou UniversityGuiyang 550025China School of Physics and Electronic Science Zunyi Normal UniversityZunyi 563006China Faculty of Physics Shahrood University of TechnologyShahroodIran Department of Physics University of Hradec KrálovéRokitanského 6250003 Hradec KrálovéCzechia College of Physics Guizhou UniversityGuiyang 550025China

By considering the concept of a unified single fluid model,referred to as modified Chaplygin gas(MCG),which amalgamates dark energy and dark matter,we explore the thermodynamic characteristics of charged anti-de Sitter(AdS)black holes existing in an unconventional fluid accompanied by *** accomplish this objective,we derive the equations of state by regarding the charge Q^(2) as a thermodynamic *** effects of MCG parameters on the critical thermodynamic quantities(ψ_(c),T_(c),Q_(c)^(2))are examined,followed by a detailed analysis of the Q^(2)-ψ *** provide a clearer explanation of the phase transition,we present an analysis of the Gibbs free *** is important to note that if the Hawking temperature exceeds the critical temperature,a distinct pattern is observed known as swallowtail *** indicates that the system undergoes a first-order phase transition from a smaller black hole to a larger *** critical exponent of the system is found to be in complete agreement with that of the van der Waals fluid ***,we investigate the impact of MCG parameters and black hole charge on Joule-Thomson(J-T)expansion in the extended phase *** J-T coefficient is examined to pinpoint the exact region experiencing cooling or heating,and the observation reveals that the presence of negative heat capacity results in the occurrence of a cooling *** impact of MCG on the inversion curve of charged black holes exhibits a striking resemblance to that observed in most multi-dimensional black hole *** addition,it is worth noting that certain parameters exert a significant influence on the ratio T_(min)/*** specific values of the MCG parameters,the ratio is consistent with the charged AdS black *** parametersγandβhave a non-negligible effect on the isenthalpic curve.

关键词： black hole dark matter dark energy phase transition Joule-Thomson expansion

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Quasi-normal modes,emission rate,and shadow of charged AdS black holes with perfect fluid dark matter

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Chinese Physics C 2024年第8期48卷 246-256页

作者： Hao Chen Shi-Hai Dong Sepehr Hassanabadi Narges Heidari Hassan Hassanabadi School of Physics and Electronic Science Zunyi Normal UniversityZunyi 563006China Research Center for Quantum Physics Huzhou UniversityHuzhou 313000China Centro de Investigación en Computación Instituto Politécnico NacionalUPALMMexico City 07700Mexico Department of Physics University of TehranNorth Karegar AvenueTehran 14395-547Iran Faculty of Physics Shahrood University of TechnologyShahroodIran Department of Physics University of Hradec KrálovéRokitanského 6250003 Hradec KrálovéCzechia

In this study,we comprehensively investigated charged AdS black holes surrounded by a distinct form of dark *** particular,we focused on key elements including the Hawking temperature,quasi-normal modes(QNMs),emission rate,and *** first calculated the Hawking temperature,thereby identifying critical values such as the critical radius and maximum temperature of the black hole,essential for determining its phase *** analysis focused on the QNMs of charged AdS black holes immersed in perfect fluid dark matter(PFDM)within the massless scalar field *** the Wentzel-Kramers-Brillouin(WKB)method,we accurately derived the frequencies of these ***,we conducted a meticulous assessment of how the intensity of the PFDM parameterαinfluences the partial absorption cross sections of the black hole,along with a detailed study of the frequency variation of the energy emission *** pivotal role of geodesics in understanding astrophysical black hole characteristics is ***,we examined the influence of the dark matter parameter on photon evolution by computing the shadow radius of the black *** findings distinctly demonstrate the significant impact of the PFDM parameterαon the boundaries of this shadow,providing crucial insights into its features and *** also provide profound insights into the intricate dynamics between a charged AdS black hole,novel dark matter,and various physical phenomena,elucidating their interplay and contributing valuable knowledge to the understanding of these cosmic entities.

关键词： black hole dark matter quasi-normal modes greybody factor shadow radius

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Magmatic-tectonic response of the South china Craton to the Paleo-Pacific subduction during the Triassic:a new viewpoint based on Well NK-1

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Journal of Oceanology and Limnology 2024年第1期42卷 58-89页

作者： Chan WANG Hao LIU Gang LI Zhen SUN Tingting GONG Li MIAO Xiaowei ZHU Yunying ZHANG Weihai XU Wen YAN Key Laboratory of Ocean and Marginal Sea Geology South China Sea Institute of OceanologyChinese Academy of SciencesGuangzhou 510301China Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou) Guangzhou 511458China Key Laboratory of Tectonic Controlled Mineralization and Oil Reservoir of ministry of Natural Resources Chengdu University of TechnologyChengdu 610059China School of Earth Sciences and Resources China University of Geosciences(Beijing)Beijing 100083China College of Earth Science Chengdu University of TechnologyChengdu 610059China University of Chinese Academy of Sciences Beijing 100049China

The Nansha Block(NB)is one of the blocks separated from the southern margin of the South china Craton(SCC)by the western Pacific subduction,which contains rich information of geodynamic and tectonic *** reveal the essence of western Paleo-Pacific subduction during the Triassic period,Well NK-1 in this block was selected for petrographic study,and published research data from other cooperative teams were compared.A double-cycle pattern of basic to neutral magmatic volcanism was established,and 36 lithological rhythmic layers and representative cryptoexplosive breccia facies and welded tuff bands were *** with a reanalysis of published geochronological data,geochemical elements,and isotope geochemistry,we found that the rock assemblages could be divided into an intermediate-acid dacite(DA)series(SiO_(2)>65%)and basaltic(BA)series(Co<40μg/g),which was formed during the early Late Triassic((218.6±3.2)–(217.9±3.5)Ma).BA exhibits obvious calc-alkaline island-arc magmatic properties:(^(87)Sr/^(86)Sr)_i ratio ranging 0.70377–0.71118(average:0.70645),^(147)Sm/^(144)Nd ratio ranging 0.119–0.193(average:0.168),and chondrite-normalized rare earth element(REE)curves being flat,while DA exhibits remarkable characteristics of subducted island-arc andesitic magma:(^(87)Sr/^(86)Sr)_i ratio(0.70939–0.71129;average:0.71035),εNd(t)value(-6.2–-4.8;average:-5.6)andε_(Hf)(t)value(-2.9–-1.7,average:-2.2)show obvious crust-mantle mixing *** and DA reveal typical characteristics of island-arc magma systems and typeⅡenriched mantle(EM-Ⅱ)*** magma was likely resulted from the process whereby the continental crust frontal accretionary wedge was driven by the Paleo-Pacific slab subduction into the deep and began to melt,resulting in a large amount of melt(fluid)joined the asthenosphere on the side of the continental *** contrast,DA magma was likely resulted from the process whereby the plate front was forced to bend with increasing subducti

关键词： Paleo-Pacific tectonic domain tectonic evolution rift volcanic rock Nansha Block South china Craton

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比较三种稳定剂对FeS纳米颗粒的稳定效果及对水土中镉的固定与去除性能的影响

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Journal of Central South University 2024年第4期31卷 1064-1075页

作者：田舒婷赵东叶霍丽娟马骏杨睿 Department of Environmental Science School of Environment and ResourcesTaiyuan University of Science and TechnologyTaiyuan 030024China Environmental Engineering Program Department of Civil&Environmental EngineeringAuburn UniversityAuburnAL 36849USA Department of Civil Constructionand Environmental EngineeringSan Diego State UniversitySan DiegoCA 92182USA

本研究评估了三种多糖稳定剂(羧甲基纤维素钠(CMC)、羧甲基淀粉钠(CMS)和一种水溶性淀粉)用于稳定FeS纳米颗粒的有效性,并测试了相应稳定化纳米颗粒在水和土壤中固定Cd^(2+)的性能。使用0.010 wt%CMC、0.025 wt%CMS或0.065 wt%淀粉可获... 详细信息

本研究评估了三种多糖稳定剂(羧甲基纤维素钠(CMC)、羧甲基淀粉钠(CMS)和一种水溶性淀粉)用于稳定FeS纳米颗粒的有效性,并测试了相应稳定化纳米颗粒在水和土壤中固定Cd^(2+)的性能。使用0.010 wt%CMC、0.025 wt%CMS或0.065 wt%淀粉可获得完全稳定的FeS纳米颗粒(100 mg/L FeS)。CMC-FeS表现出较高的zeta负电位,淀粉-FeS保持中性,而CMS-FeS则表现出中等负电位。CMCFeS对Cd^(2+)的吸附速率最快,吸附容量也最高。当用100 mg/L CMC-FeS或CMS-FeS处理一种含Cd土壤(58.3 mg/kg Cd)后,Cd的TCLP浸出率分别降低了88.4%和68.0%。CMC-FeS和CMS-FeS均可在模型土壤中运移,显示出其在土壤中原位固定Cd^(2+)方面的潜力。土壤穿透曲线实验表明,CMC-FeS在4.5个孔体积,CMS-FeS在约25个孔体积处几乎完全穿透。柱实验结果表明,当用55个孔体积的CMC-FeS或CMS-FeS悬浮液(100 mg/L)处理该含Cd土壤后,Cd的水浸出率分别降低了98.2%和98.0%。根据目标污染物、材料在土壤中的传输特性和材料成本,可找到这三种稳定剂在土壤修复中的最佳应用。

关键词：硫化铁纳米颗粒稳定剂重金属污染物固定土壤修复地下水污染

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Linking 24-h Movement Behavior Guidelines to Cognitive Difficulties,Internalizing and Externalizing Problems in Preterm Youth

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International Journal of Mental Health Promotion 2024年第8期26卷 651-662页

作者： Zhihui Cheng Ailikute Aikeremu Yanping Gao Zhihao Zhang Anthony G.Delli Paoli Paolo Marcello Cunha Alyx Taylor Fabian Herold Liye Zou Body-Brain-Mind Laboratory School of PsychologyShenzhen UniversityShenzhen518060China Department of Kinesiology and Health Rutgers UniversityNew BrunswickNJ 08901USA Metropolitan University Center of Maringá Maringá87020Brazil School of Health and Rehabilitation Sciences AECC University CollegeBournemouthBH52DFUK Research Group Degenerative and Chronic Diseases MovementFaculty of Health Sciences BrandenburgUniversity of PotsdamPotsdam14476Germany

Background:Given the heightened risk of developmental challenges associated with preterm birth,it is crucial to explore interventions that may ameliorate potential adverse *** study aimed to examine whether meeting the 24-h movement behavior(24-HMB)guidelines,which include recommendations on physical activity(PA),screen time(ST),and sleep(SL),is related to indicators of cognitive difficulties,internalizing problems(e.g.,depression and anxiety),and externalizing problems(e.g.,difficulties in making friends and arguing)in a sample of preterm youth(children and adolescents born preterm).Methods:In this cross-sectional study,data from 3410 preterm youth(aged 6 to 17 years)were included for data *** logistic regression was used to investigate associations between meeting the 24-HMB guidelines and the above-mentioned health outcomes,while controlling for sociodemographic and health-related ***:The prevalence of meeting 24-HMB guidelines varied across independent and integrated components of the 24-HMB *** the ST guideline alone(p<0.05)and integrated guidelines(i.e.,ST+SL and ST+SL+PA)were associated with fewer cognitive difficulties and reduced internalizing and externalizing problems(p<0.05).Specifically,meeting the SL guideline alone and integrated guidelines(i.e.,SL+ST)were associated with lower odds of depression and anxiety(p<0.01).Additionally,meeting independent,and integrated(PA and/or ST)guidelines were associated with less pronounced difficulties in making friends and arguing(p<0.05).Meeting 24-HMB guidelines in an isolated and integrated manner are linked to better cognitive performance and fewer internalizing and externalizing problems in preterm ***:Results suggest that advocating for the implementation of the 24-HMB guidelines may reduce cognitive challenges and behavioral issues,which is of high relevance for improving public *** longitudinal studies in preterm youth should inves

关键词： Cognitive difficulties externalizing problems internalizing problems physical activity preterm youth

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An air-stable single-crystal layered oxide cathode based on multifunctional structural modulation for high-energy-density sodium-ion batteries

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Science china Chemistry 2024年

作者： Yi-Feng Liu Hai-Yan Hu Jia-Yang Li Hongrui Wang Yi Zhao Jingqiang Wang Yuan-Bo Wu Yan-Jiang Li Guang-Yu Zhang Qing-Qun Sun Yan-Fang Zhu Rui-Ren Tang Xiong-Wei Wu Jia-Zhao Wang Shi-Xue Dou Shu-Lei Chou Yao Xiao Key Laboratory of Advanced Energy Materials Chemistry (ministry of education) Nankai University School of Chemistry and Materials Science Hunan Agricultural University Institute of Energy Materials Science University of Shanghai for Science and Technology Wenzhou Key Laboratory of Sodium-Ion Batteries Wenzhou University Technology Innovation Institute for Carbon Neutralization Institute for Carbon Neutralization College of Chemistry and Materials Engineering Wenzhou University College of Chemistry and Chemical Engineering Central South University

P2-type layered oxide, Na2/3Ni1/3Mn2/3O2, has drawn particular interest as a promising cathode material for sodium-ion batteries(SIBs) due to its fast sodium-ion transport channels with low migration potential. However, some catastrophic flaws, such as air instability, complicated multiphase evolution, and irreversible anionic redox, limit its electrochemical performance and hinder its application. Here, an air-stable single-crystal P2-type Na2/3Ni1/3Mn1/3Ti1/3O2is proposed based on the multifunctional structural modulation of Ti substitution that could alleviate the issues for practical SIBs. As a result, the cathode with high energy density shows excellent air stability and highly reversible phase transitions(P2–OP4), and delivers faster kinetics and stable anion redox chemistry. Meanwhile, a thorough investigation of the relationship between structure, function, and properties is demonstrated,emphasizing formation processes, electrochemical behavior, structural evolution, and air stability. Overall, this study provides the direction of multifunctional structural modulation for the development of high-performance sodium-based layered cathode materials for practical applications.

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DYNAMICS FOR A CHEMOTAXIS MODEL WITH GENERAL LOGISTIC DAMPING AND SIGNAL DEPENDENT MOTILITY

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Acta Mathematica Scientia 2024年第3期44卷 1046-1063页

作者：涂馨予穆春来邱蜀燕张静 School of Mathematics and Statistics Southwest UniversityChongqing400715China Department of Applied Mathematics The Hong Kong Polytechnic UniversityHung HomHong KongChina College of Mathematics and Statistics Chongqing UniversityChongqing401331China School of Sciences Southwest Petroleum UniversityChengdu610500China

In this paper,we consider the fully parabolic Chemotaxis system with the general logistic source{ut=Δ(γ(v)u)+λu-μu^(k),x∈Ω,t>0,vt=△v+wz,x∈Ω,t>0,wt=-wz,x∈Ω,t>0,zt=△z-z+u,x∈Ω,t>0 whereΩ⊂ℝn(n≥1)is a smooth and bounded domain,λ≥0,μ≥0,κ>1,and the motility function satisfies thatγ(v)∈C3([0,∞)),γ(v)>0,γ′(v)≤0 for all v≥*** the Neumann boundary condition,we obtain the global boundedness of solutions if one of the following conditions holds:(i)λ=μ=0,1≤nλ3;(ii)λ>0,μ>0,combined withκ>1,1≤n≤3 or k>n+2/4,,n>***,we prove that the solution (u, v, w, z) exponentially converges to the constant steady state ((λ/μ)1/k-1,∫Ωv0dx+∫Ωw0dx/|Ω|,0,(λ/μ)1/k-1).

关键词： chemotaxis signal-dependent motility logistic source boundedness asymptotic behavior

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Design of high-temperature superconductors at moderate pressures by alloying AlH3 or GaH3

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Matter and Radiation at Extremes 2024年第1期9卷 94-103页

作者： Xiaowei Liang Xudong Wei Eva Zurek Aitor Bergara Peifang Li Guoying Gao Yongjun Tian Center for High Pressure Science(CHiPS) State Key Laboratory of Metastable Materials Science and TechnologyYanshan UniversityQinhuangdao 066004China School of Materials Science and Engineering Henan University of TechnologyZhengzhou 450001China Department of Chemistry State University of New York at BuffaloBuffaloNew York 14260-3000USA Physics Department and EHU Quantum Center University of the Basque CountryUPV/EHU48080 BilbaoSpain Donostia International Physics Center(DIPC) 20018 DonostiaSpain Centro de Física de Materiales CFM Centro Mixto CSIC-UPV/EHU20018 DonostiaSpain Extreme Conditions Physics Research Team College of Physics and Electronic InformationInner Mongolia Minzu UniversityTongliao 028043China

Since the discovery of hydride superconductors,a significant challenge has been to reduce the pressure required for their *** this context,we propose that alloying could be an effective strategy to achieve *** focus on a series of alloyed hydrides with the AMH_(6)composition,which can be made via alloying A15 AH_(3)(A=Al or Ga)with M(M=a group IIIB or IVB metal),and study their behavior under *** of them are predicted to maintain the A15-type structure,similar to AH_(3)under pressure,providing a platform for studying the effects of alloying on the stability and superconductivity of AH_(3).Among these,the A15-type phases of AlZrH_(6)and AlHfH_(6)are found to be thermodynamically stable in the pressure ranges of 40–150 and 30–181 GPa,***,they remain dynamically stable at even lower pressures,as low as 13 GPa for AlZrH_(6)and 6 GPa for AlHfH_(6).These pressures are significantly lower than that required for stabilizing A15 ***,the introduction of Zr or Hf increases the electronic density of states at the Fermi level compared with *** enhancement leads to higher critical temperatures(Tc)of 75 and 76 K for AlZrH_(6)and AlHfH_(6)at 20 and 10 GPa,*** the case of GaMH_(6)alloys,where M represents Sc,Ti,Zr,or Hf,these metals reinforce the stability of the A15-type structure and reduce the lowest thermodynamically stable pressure for GaH_(3) from 160 GPa to 116,95,80,and 85 GPa,*** noteworthy are the A15-type GaMH_(6)alloys,which remain dynamically stable at low pressures of 97,28,5,and 6 GPa,simultaneously exhibiting high Tc of 88,39,70,and 49 K at 100,35,10,and 10 GPa,***,these findings enrich the family of A15-type superconductors and provide insights for the future exploration of high-temperature hydride superconductors that can be stabilized at lower pressures.

关键词： alloying alloys superconductors

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NUMERICAL SIMULATION OF TURBULENT SPOTS IN INCLINED OPEN-CHANNEL FLOW

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Journal of Hydrodynamics 2005年第2期17卷 179-185页

作者： ZHANGLi TANGDeng-bin CollegeofAerospaceEngineering NanjingUniversityofAeronauticsandAstronauticsNanjing210016China

The generation and evolution of turbulent spots in the open-channel flow are simulated numerically by using the Navier-Stokes equations. An effective numerical method with high accuracy and high resolution is developed. The fourth-order time splitting methods with high accuracy is proposed. Three-dimensional coupling difference methods are presented for the spatial discretization of the Poisson equation of pressure and Hemholtz equations of velocity, therefore, the fourth-order three-dimensional coupling central difference schemes are constituted. The fourth-order explicit upwind-biased compact difference schemes are designed to overcome the difficulty for the general higher-order central difference scheme which is inadaptable in the boundary neighborhood. The iterative algorithm and overall time marching is used to enhance efficiency. The method is applied in the numerical simulation of turbulent spots at various complex boundary conditions and flow domains. The generation and the developing process of turbulent spots are given, and the basic characteristics of turbulent spots are shown by simulating the evolution of the wall pulse in inclined open-channel flow.

关键词： turbulent spot Navier-Stokes equation numerical simulation three-dimensional coupling difference scheme wall pulse

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Effects of sintering pressure and temperature on microstructure and tribological characteristic of Cu-based aircraft brake material

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中国有色金属学会会刊：英文版 2007年第4期17卷 669-675页

作者：熊翔盛洪超陈洁姚萍屏State Key Laboratory of Powder Metallurgy Central South University State Key Laboratory of Powder Metallurgy Central South University

A novel Cu-based P/M aircraft brake material was prepared and the effects of sintering pressure and temperature on microstructure and tribological characteristic were investigated. For the constant sintering temperature, when the sintering pressure increases from 0.5 MPa to 1.5 MPa, the porosity, wear loss and friction coefficient decrease remarkably. When the sintering pressure increases from 1.5 MPa to 2.5 MPa, the porosity further decreases but in a little degree and wear behaviors are improved slightly. However, once the sintering pressure is larger than 2.5 MPa, it has no obvious effect on microstructure and tribological characteristic. For the constant sintering pressure, when the sintering temperature increases from 900 ℃ to 930 ℃, the sintered density remarkably increases, and wear behaviors are obviously improved. For further increasing sintering temperature to 1 000 ℃, the density keeps on increasing, but wear behaviors change slightly.

关键词：摩擦材料烧结压力烧结温度飞机制动材料铜基材料微观结构

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