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Convergence of a Generalized Riemann Problem Scheme for the Burgers Equation

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Communications on Applied mathematics and Computation 2024年第4期6卷 2215-2238页

作者： mária Lukáčová-medvid’ová Yuhuan Yuan Institute of mathematics Johannes Gutenberg-University MainzStaudingerweg 955128MainzGermany School of mathematics Nanjing University of Aeronautics and Astronautics211106NanjingJiangsuChina

In this paper,we study the convergence of a second-order finite volume approximation of the scalar conservation *** scheme is based on the generalized Riemann problem(GRP)*** first investigate the stability of the GRP scheme and find that it might be entropy-unstable when the shock wave is *** adding an artificial viscosity,we propose a new stabilized GRP *** the assumption that numerical solutions are uniformly bounded,we prove the consistency and convergence of this new GRP method.

关键词： Scalar conservation law Finite volume method Generalized Riemann problem(GRP)solver Entropy stability Consistency Convergence

Advantageous mechanochemical synthesis of copper(Ⅰ)selenide semiconductor,characterization,and properties

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Frontiers of Chemical Science and Engineering 2022年第3期16卷 433-442页

作者： Katarína Gáborová marcela Achimovičová michal Hegedüs Vladimír Girman mária Kaňuchová Erika Dutková Institute of Geotechnics Slovak Academy of SciencesKošice04001Slovakia Institute of metallurgy Faculty of MaterialsMetallurgy and RecyclingTechnical UniversityKošice04201Slovakia Synthon s.r.o.Blansko67801Czech Republic Faculty of Science Pavol JozefŠafárik UniversityKošice04154Slovakia Institute of Earth Resources Faculty of MiningEcologyProcess Control and GeotechnologiesTechnical UniversityKošice04200Slovakia

Copper(I)selenide-nanocrystalline semiconductor was synthesized via one-step mechanochemical synthesis after 5 min milling in a planetary ball *** kinetics of synthesis was followed by X-ray powder diffraction analysis and specific surface area measurements of milled 2Cu/Se *** X-ray diffraction confirmed the orthorhombic crystal structure of Cu_(2)Se with the crystallite size∼25 *** surface chemical structure was studied by X-ray photoelectron spectroscopy,whereby the binding energy of the Cu 2p and Se 3d signals corresponded to Cu^(+)and Se^(2−)oxidation *** electron microscopy revealed agglomerated nanocrystals and confirmed their orthorhombic structure,as *** optical properties were studied utilizing ultraviolet-visible spectroscopy and photoluminescence *** direct bandgap energy 3.7 eV indicated a blue-shift phenomenon due to the quantum size *** type of Cu_(2)Se synthesis can be easily adapted to production dimensions using an industrial vibratory *** advantages of mechanochemical synthesis represent the potential for inexpensive,environmentally-friendly,and waste-free manufacturing of Cu_(2)Se.

关键词： Cu_(2)Se berzelianite nanocrystalline semiconductor mechanochemical synthesis planetary ball mill

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ImEX Large Time Step Finite Volume methods for Low Froude Number Shallow Water Flows

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Communications in Computational Physics 2014年第7期16卷 307-347页

作者： Georgij Bispen K.R.Arun mária Lukácová-medvid’ová Sebastian Noelle Institute of mathematics University of MainzGermany School of mathematics Indian Institute of Science Education and Research ThiruvananthapuramIndia IGPm RWTH AachenGermany.

We present new large time step methods for the shallow water flows in the lowFroude number *** order to take into accountmultiscale phenomena that typically appear in geophysical flows nonlinear fluxes are split into a linear part governing the gravitational waves and the nonlinear *** propose to approximate fast linear waves implicitly in time and in space bymeans of a genuinely multidimensional evolution *** the other hand,we approximate nonlinear advection part explicitly in time and in space bymeans of themethod of characteristics or some standard numerical flux *** integration is realized by the implicit-explicit(ImEX)*** apply the ImEX Euler scheme,two step Runge Kutta Cranck Nicolson scheme,as well as the semi-implicit BDF scheme and prove their asymptotic preserving property in the low Froude number *** experiments demonstrate stability,accuracy and robustness of these new large time step finite volume schemes with respect to small Froude number.

关键词： LowFroude number flows asymptotic preserving schemes shallowwater equations large time step semi-implicit approximation evolution Galerkin schemes

SOLID STATE PROPERTIES AND LEACHING OF mECHANICALLY ACTIVATED TETRAHEDRITE

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Acta metallurgica Sinica(English Letters) 1994年第2期7卷 79-83页

作者： BAL■P ACHImovI■ovm SEPLAKV BASTLZ LIPAKJ

The mechanical activation of tetrahedrite Cu_(12)Sb_(4)S_(13) was carried out in a planetary mill. The changes in the surface and bulk properties produced in mineral by mechanical activation were detected by infrared, photoelectron and mossbauer spectroscopy. The rate and selectivity of tetrahedrite acid leaching depends on conditions of mechanical activation.

关键词： mechanical activation leaching tetrahedrite

ON CLASSES OF REGULAR GRAPHS WITH CONSTANT mETRIC DImENSION

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Acta mathematica Scientia 2013年第1期33卷 187-206页

作者： muhammad ImRAN Syed Ahtsham ul Haq BOKHARY Ali AHmAD Andrea SEmANIov-FENovíKov Centre for Advanced mathematics and Physics(CAmP) National University of Sciences and Technology(NUST) Center for Advanced Studies in Pure and Applied mathematics Bahauddin Zakariya University College of Computer and Information System Jazan University Department of Applied mathematics and Informatics Technical University

In this paper, we are dealing with the study of the metric dimension of some classes of regular graphs by considering a class of bridgeless cubic graphs called the flower snarks Jn, a class of cubic convex polytopes considering the open problem raised in [m. Imran et al., families of plane graphs with constant metric dimension, Utilitas math., in press] and finally Harary graphs H5,n by partially answering to an open problem proposed in Ⅱ. Javaid et al., Families of regular graphs with constant metric dimension, Utilitas math., 2012, 88： 43-57]. We prove that these classes of regular graphs have constant metric dimension.

关键词： metric dimension basis resolving set cubic graph flower snark convexpolytope

Wireless organic electronic ion pumps driven by photovoltaics

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npj Flexible Electronics 2019年第1期3卷 126-131页

作者： marie Jakešová Theresia Arbring Sjöström VedranĐerek David Poxson magnus Berggren Eric Daniel Głowacki Daniel T.Simon Laboratory of Organic Electronics ITN Campus NorrköpingLinköping UniversitySE-60174 NorrköpingSweden Wallenberg Centre for molecular medicine Linköping UniversitySE-58185 LinköpingSweden

The organic electronic ion pump(OEIP)is an emerging bioelectronic technology for on-demand and local delivery of pharmacologically active species,especially targeting alkali ions,and *** electrical control is advantageous for providing precise spatial,temporal,and quantitative delivery,traditionally,it necessitates *** complicates ***,we demonstrate integration of an OEIP with a photovoltaic driver on a flexible carrier,which can be addressed by red light within the tissue transparency *** thin-film bilayer photovoltaic pixels are arranged in series and/or vertical tandem to provide the 2.5–4.5 V necessary for operating the high-resistance electrophoretic ion *** demonstrate light-stimulated transport of cations,ranging in size from protons to *** device,laminated on top of the skin,can easily be driven with a red LED emitting through a 1.5-cm-thick *** end result of our work is a thin and flexible integrated wireless device platform.

关键词： precise transparency alkali

Homogenization of twin-roll cast AA8079 aluminum alloy studied by in-situ TEm

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Transactions of Nonferrous metals Society of China 2022年第7期32卷 2138-2149页

作者： R.KRÁLÍK B.KŘIVSKÁ L.BAJTOŠovÁ m.ŠLAPÁKovÁ m.CIESLAR Faculty of mathematics and Physics Charles UniversityKe Karlovu 312116 Prague 2Czechia

AA8079 is a commonly used stock material for manufacturing thin packaging *** primary alloying elements Fe and Si can form binary and tertiary ***-situ TEm simulating homogenization annealing process of the as-cast material was used to analyze the real-time changes of the shape,type,and distribution of these *** affect the mechanical properties of the final product and susceptibility of the material to the formation of pinholes and other macroscopic *** set of as-cast samples were annealed in a regime simulating industrial treatment in combination with measurements of resistivity to validate the results of the in-situ *** results show clear temperature intervals of recovery,matrix desaturation,and phase transformations occurring in several stages:spheroidization of the original particles above 450℃,nucleation of new particles at 475℃,particles coarsening above 525℃,and an entire dissolution of the original particles above 550℃.

关键词： aluminum alloys in-situ annealing homogenization foil stock materials

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SPEED:an integrated,smartphone-operated,handheld digital PCR Device for point-of-care testing

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microsystems & Nanoengineering 2024年第3期10卷 149-158页

作者： Haoqing Zhang Xiaocheng Liu Xinlu Wang Zhiqiang Yan Ying Xu martina Gaňová TomášŘezníček marie Korabečná Pavel Neuzil ministry of Education Key Laboratory of micro and Nano Systems for Aerospace School of Mechanical EngineeringNorthwestern Polytechnical University127 West Youyi RoadXi’anShaanxi 710072PR China The Key Laboratory of Biomedical Information Engineering of the ministry of Education School of Life Science and TechnologyXi’an Jiaotong UniversityXi’anShaanxi 710049PR China Bioinspired Engineering and Biomechanics Center(BEBC) Xi’an Jiaotong UniversityXi’an 710049PR China School of marine Science and Technology Northwestern Polytechnical UniversityXi’anShaanxi 710072PR China Central European Institute of Technology Brno University of TechnologyPurkyňova 12361300 BrnoCzech Republic ITD Tech S.R.O Osvoboditelu100573581 BohumínCzech Republic Institute of Biology and medical Genetics First Faculty of MedicineCharles University and General University Hospital of PragueAlbertov 412800 PragueCzech Republic

This study elaborates on the design,fabrication,and data analysis details of SPEED,a recently proposed smartphonebased digital polymerase chain reaction(dPCR)*** dPCR chips incorporate partition diameters ranging from 50μm to 5μm,and these partitions are organized into six distinct blocks to facilitate image *** to the superior thermal conductivity of Si and its potential for mass production,the dPCR chips were fabricated on a Si substrate.A temperature control system based on a high-power density Peltier element and a preheating/cooling PCR protocol user interface shortening the thermal cycle *** optical design employs four 470 nm light-emitting diodes as light sources,with filters and mirrors effectively managing the light emitted during *** algorithm is utilized for image processing and illumination nonuniformity correction including conversion to a monochromatic format,partition identification,skew correction,and the generation of an image correction *** validated the device using a range of deoxyribonucleic acid targets,demonstrating its potential applicability across multiple ***,we provide guidance and verification of the design and testing of the recently proposed SPEED device.

关键词： correction smart testing

Biodegradable zinc-iron alloys: Complex study of corrosion behavior,mechanical properties and hemocompatibility

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Progress in Natural Science:materials International 2021年第2期31卷 279-287页

作者： Z.Orságová Králová R.Gorejová R.Orin?aková m.Petra?ková A.Orin?ak m.Kupková m.Hrubov?a?ková T.Sop?ák m.Baláz? I.maska?ová A.Kovalc?íková K.Kova? Department of Physical Chemistry Faculty of Science Pavol Jozef ?afa?rik University in Ko?ice Institute of materials Research Slovak Academy of Sciences Institute of Geotechnics Slovak Academy of Sciences University of Veterinary medicine and Pharmacy in Ko?ice Department of Animal Nutrition Dietetics and Animal Breeding

Zn-Fe alloys have been extensively investigated in this study with a view to their application as biodegradable bone implants. Biogenic element zinc is a very appropriate metal because of the ideal degradation rate compared to those of mg and Fe. Studied alloys were made by compressing metallic powders in a content ratio of 100% Zn,Zn-1% Fe, Zn-2% Fe, Zn-5% Fe and Zn-10% Fe and sintering at 350°C for 1 h. Prepared samples were examined by optical microscopy, SEm and XRD. Corrosion behavior, mechanical testing and hemocompatibility were observed subsequently. The electrochemical performance of such materials was studied in the simulated body fluids. The enhanced corrosion rate was observed for all samples after iron addition due to the micro-galvanic effect between the pure Zn and Zn11Fe intermetallic phase. The corrosion rate of the Zn-5% Fe alloyed sample was more than 20-times higher（2.89 mmpy） compared to the pure Zn. However, alloying with more than 5 wt %of iron diminished the mechanical performance of the material. Therefore, the performed mechanical and hemocompatibility tests showed acceptable biocompatibility of zinc and Zn-1% Fe and Zn-2% Fe samples.

关键词： Biodegradable materials Zinc Iron Alloy Corrosion behavior Hemocompatibility