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Applied Mathematics and Mechanics(English Edition) 2024年第6期45卷 947-962页

作者： N.IQBAL J.chOI s.f.sh.h.c.lee s.lee Department of Mechanical Roboticsand Energy EngineeringDongguk University-SeoulSeoul 04620Republic of Korea

A chemo-mechanical model is developed to investigate the effects on the stress development of the coating of polycrystalline Ni-rich LiNixMnyco_(z)O_(2)(x≥0.8)(NMc)particles with poly(3,4-ethylenedioxythiophene)(PEDOT).The simulation results show that the coating of primary NMc particles significantly reduces the stress generation by efficiently accommodating the volume change associated with the lithium diffusion,and the coating layer plays roles both as a cushion against the volume change and a channel for the lithium transport,promoting the lithium distribution across the secondary particles more ***,the lower stiffness,higher ionic conductivity,and larger thickness of the coating layer improve the stress *** paper provides a mathematical framework for calculating the chemo-mechanical responses of anisotropic electrode materials and fundamental insights into how the coating of NMc active particles mitigates stress levels.

关键词： lithium-ion battery(LIB) polycrystalline particle coating finite element simulation Ni-rich LiNixMnyco_(z)O_(2)(x>0.8)(NMc)

superplasticity of fine-grained Mg-10Li alloy prepared by severe plastic deformation and understanding its deformation mechanisms

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Journal of Magnesium and Alloys 2024年第1期12卷 316-331页

作者： h.T.Jeong s.W.lee W.J.Kim Department of Materials science and Engineering Hongik UniversityMapo-guSangsu-dong 72-1Seoul 121-791Republic of Korea

The superplastic behavior and associated deformation mechanisms of a fine-grained Mg-10.1 Li-0.8Al-0.6Zn alloy(LAZ1011)with a grain size of 3.2μm,primarily composed of the Bccβphase and a small amount of the hcPαphase,were examined in a temperature range of 473 K to 623 *** microstructural refinement of this alloy was achieved by employing high-ratio differential speed *** best superplasticity was achieved at 523 K and at strain rates of 10^(-4)-5×10^(-4)s^(-1),where tensile elongations of 550±600%were *** the heating and holding stage of the tensile samples prior to tensile loading,a significant increase in grain size was observed at temperatures above 573 ***,it was important to consider this effect when analyzing and understanding the superplastic deformation behavior and *** the investigated strain rate range,the superplastic flow at low strain rates was governed by lattice diffusion-controlled grain boundary sliding,while at high strain rates,lattice diffusion-controlled dislocation climb creep was the rate-controlling deformation *** was concluded that solute drag creep is unlikely to *** the late stages of deformation at 523 K,it was observed that grain boundary sliding led to the agglomeration of theαphase,resulting in significant strain *** mechanism maps were constructed forβ-Mg-Li alloys in the form of 2D and 3D formats as a function of strain rate,stress,temperature,and grain size,using the constitutive equations for various deformation mechanisms derived based on the data of the current tests.

关键词： Magnesium-lithium alloy superplasticity severe plastic deformation Grain size Grain growth

Ethnocultural heritage of the North-Eastern caucasus as a factor of eco-tourism development

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Journal of Mountain science 2024年第8期21卷 2810-2824页

作者： Zaburaeva Khava sh. complex Research Institute named after Kh.I.Ibragimov of the Russian Academy of sciences Grozny 366002Russia

The North-East caucasus is a multi-ethnic mountain macroregion with a rich cultural heritage,insufficiently studied in the context of the ecotourism *** fill this gap and identify promising directions of environmentally safe forms of tourism,the author used in-depth review of modern literature to investigate the features of ecological tourism and the problems of preserving ethno-cultural heritage,and used historical and comparative-geographical methods to analyze the development of the tangible and intangible cultural heritage of the indigenous peoples of the North-Eastern caucasus in different historical periods and to identify the geographical peculiarities of the distribution of historical and cultural monuments(tower buildings),pilgrimage sites and centers of traditional crafts and *** part of the planned expeditions,the author personally visited some historical monuments and handicraft centers for a deeper study of ethno-cultural *** cartographic method made it possible to visualize the *** results of the research show that the ethnocultural heritage of the North-East caucasus is formed by material(historical and cultural monuments)and immaterial elements of culture(language,customs,traditions,ethnic identification)of those peoples,who live *** ethnocultural heritage is considered as the most important factor in the development of the tourism *** is revealed that this region has a large potential for development in various areas of *** highest concentration of religious buildings focused in mountainous *** tower structures were erected in mountainous and high-altitude *** ancient times to the present day there have been preserved various types of crafts and trades(pottery,metalworking,burka making,jewelry making,carpet weaving,gold embroidery,wood and stone carving,etc.),which can become objects of *** ethnocultural heritage of the North-East caucasus needs to be preserved a

关键词： Mountainous districts sustainable development Prospects stone Towers folk crafts

Generalized polynomial chaos expansion by reanalysis using static condensation based on substructuring

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Applied Mathematics and Mechanics(English Edition) 2024年第5期45卷 819-836页

作者： D.lee s.chANG J.lee Department of Automotive Engineering Hanyang UniversitySeoul 04763Republic of Korea school of Mechanical Engineering Chungnam National UniversityDaejeon 34134Republic of Korea Department of Mechanical Robotics and Energy EngineeringDongguk UniversitySeoul 04620Republic of Korea

This paper presents a new computational method for forward uncertainty quantification(UQ)analyses on large-scale structural systems in the presence of arbitrary and dependent random *** method consists of a generalized polynomial chaos expansion(GPcE)for statistical moment and reliability analyses associated with the stochastic output and a static reanalysis method to generate the input-output data *** the reanalysis,we employ substructuring for a structure to isolate its local regions that vary due to random *** allows for avoiding repeated computations of invariant substructures while generating the input-output data *** substructuring with static condensation further improves the computational efficiency of the reanalysis without losing ***,the GPcE with the static reanalysis method can achieve significant computational saving,thus mitigating the curse of dimensionality to some degree for UQ under high-dimensional *** numerical results obtained from a simple structure indicate that the proposed method for UQ produces accurate solutions more efficiently than the GPcE using full finite element analyses(fEAs).We also demonstrate the efficiency and scalability of the proposed method by executing UQ for a large-scale wing-box structure under ten-dimensional(all-dependent)random inputs.

关键词： forward uncertainty quantification(UQ) generalized polynomial chaos expansion(GPcE) static reanalysis method static condensation substructuring

Effect of Eu3+,Bi3+,and Li+ doping on luminescent property of GdNbO4

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Journal of Rare Earths 2024年第1期42卷 66-75页

作者： s.W.Wi Y.s.lee Department of Physics and Integrative Institute of Basic sciences Soongsil University

We investigated the emission properties of Eu3+-doped GdNbO4-based oxide phosphors,aiming at improving the Eu3+emission by codoping of Bi3+and Li+.Eu3+singly doped,Eu3+and Bi3+doubly doped,and Eu3+,Bi3+,and Li+triply doped GdNbO4were prepared using a high-temperature solid-state reaction *** red-orange emissions from Eu3+in the singly doped samples are significantly improved by the codoping of Bi3+,mainly due to the energy transfer from Bi3+to Eu3+.The additional codoping of Li+is found to increase the Eu3+emission *** improvement might be attributed to the increase in the photoluminescent quantum yield originating from larger grain sizes and better crystallinity.A detailed analysis of the X-ray diffraction pattern and the asymmetric ratio estimated from the photoluminescence spectra show that the local lattice environment around Eu3+in GdNbO4does not change significantly with the codoping of Bi3+and Li+.Our results indicate that Li+doping is a promising way to improve the emission properties of rare-earth ion-doped GdNbO4phosphors.

关键词： Eu 3+ GdNbO 4 codoping of Li + Photoluminescence sensitizer Rare earths

All-electron basis sets for h to Xe specific for ZORA calculations:Applications in atoms and molecules

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chinese Physics B 2024年第8期33卷 238-246页

作者： c.s.Gomes f.E.Jorge A.canal Neto Departamento de fisica Universidade Federal do Espirito Santo29075-910 VitoriaESBrazil Departamento de fisica Instituto de Ciencias Exatas e BiologicasUniversidade Federal de Ouro Preto Campus Universitario Morro do Cruzeiro35402-136 Ouro PretoMGBrazil

A segmented basis set of quadruple zeta valence quality plus polarization functions(QZP)for h through Xe was developed to be used in conjunction with the ZORA *** set was augmented with diffuse functions to describe electrons farther away from the nuclei *** the ZORA-ccsD(T)/QZP-ZORA theoretical model,atomic ionization energies and bond lengths,harmonic vibrational frequencies,and atomization energies of some molecules were *** addition of core-valence corrections has been shown to improve the agreement between theoretical and experimental results for molecular *** atomization energies,a similar observation emerges when considering spin-orbit *** the augmented QZP-ZORA set,static mean dipole polarizabilities of a set of atoms were calculated and compared with previously published recommended and experimental *** evaluations of the ZORA and Douglas–Kroll–hess hamiltonians were made for each property studied.

关键词： QZP-ZORA and AQZP-ZORA basis sets elements from h to Xe ccsD(T)method atomic and molecular properties

A comprehensive Review on charging Topologies and Power Electronic converter solutions for Electric Vehicles

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Journal of Modern Power systems and clean Energy 2024年第3期12卷 675-694页

作者： Abdelfatah Ali hossam h.h.Mousa Mostafa f.shaaban Maher A.Azzouz Ahmed s.A.Awad the Department of Electrical Engineering American University of Sharjah26666 SharjahUnited Arab Emirates the Department of Electrical Engineering South Valley University83523 QenaEgypt the Department of Electrical and computer Engineering University of WindsorWindsorON N9B 3P4 Canada Electrical Engineering Department Qatar UniversityDoha 2713Qatar Department of Electrical and computer Engineering Sultan Qaboos UniversityMuscat123Oman

Electric vehicles(EVs)are becoming more popular worldwide due to environmental concerns,fuel security,and price *** performance of EVs relies on the energy stored in their batteries,which can be charged using either Ac(slow)or Dc(fast)***,EVs can also be used as mobile power storage devices using vehicle-to-grid(V2G)*** electronic converters(PEcs)have a constructive role in EV applications,both in charging EVs and in ***,this paper comprehensively investigates the state of the art of EV charging topologies and PEc solutions for EV *** examines PEcs from the point of view of their classifications,configurations,control approaches,and future research prospects and their impacts on power *** can be classified into various topologies:Dc-Dc converters,Ac-Dc converters,Dc-Ac converters,and Ac-Ac *** address the limitations of traditional Dc-Dc converters such as switching losses,size,and high-electromagnetic interference(EMI),resonant converters and multiport converters are being used in high-voltage EV ***,power-train converters have been modified for high-efficiency and reliability in EV *** paper offers an overview of charging topologies,PEcs,challenges with solutions,and future trends in the field of the EV charging station applications.

关键词： charging station charging topology electric vehicle power electronic converter vehicle-to-grid

MgO-attached graphene nanosheet(MgO@GNs)reinforced magnesium matrix nanocomposite with superior mechanical,corrosion and biological performance

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International Journal of Minerals,Metallurgy and Materials 2024年第9期31卷 2062-2076页

作者： s.Abazari A.shamsipur h.R.Bakhsheshi-Rad M.s.soheilirad f.Khorashadizade s.s.Mirhosseini Department of Materials and Metallurgical Engineering Amirkabir University of TechnologyTehran ***Iran Iranian National standards Organization of hormozgan HormozganIran Advanced Materials Research center Department of Materials EngineeringNajafabad BranchIslamic Azad UniversityNajafabadIran Department of Materials and Metallurgical Engineering Iran University of Science and TechnologyTehranIran

Magnesium(Mg)alloys are gaining great consideration as body implant materials due to their high biodegradability and ***,they suffer from low corrosion resistance and antibacterial *** this research,semi-powder metallurgy followed by hot extrusion was utilized to produce the magnesium oxide@graphene nanosheets/magnesium(MgO@GNs/Mg)composite to improve mechanical,corrosion and cytocompatibility *** have revealed that the incorporation of MgO@GNs nanohybrids into Mg-based composite enhanced microhardness and compressive *** vitro,osteoblast cell culture tests show that using MgO@GNs nanohybrid fillers enhances osteoblast adhesion and apatite *** presence of MgO@GNs nanoparticles in the composites decreased the opening defects,micro-cracks and micro-pores of the composites thus preventing the penetration of the corrosive solution into the *** demonstrated that the MgO@GNs/Mg composite possesses excellent antibacterial properties because of the combination of the release of MgO and physical damage to bacterium membranes caused by the sharp edges of graphene nanosheets that can effectively damage the cell wall thereby facilitating penetration into the bacterial lipid ***,the MgO@GNs/Mg composite with high mechanical strength,antibacterial activity and corrosion resistance is considered to be a promising material for load-bearing implant applications.

关键词： metal matrix composites MgO@GNs nanohybrid strengthening mechanisms antibacterial activity biocompatibility

circulation Pattern controls of summer Temperature Anomalies in southern Africa

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Advances in Atmospheric sciences 2024年第2期41卷 341-354页

作者： chibuike chiedozie IBEBUchI cameron c.lee Department of Geography Kent State UniversityKentOhio 44242USA climRIsE Lab Kent State UniversityKentOhio 44242USA

This study investigates the relationship between circulation patterns and austral summer temperature anomalies in southern Africa. The results show that the formation of continental lows tends to increase the thickness of the lower atmosphere. further, the distinct variabilities of high and low pressure under the circulation types, influence air mass advection from the adjacent oceans, as well as atmospheric stability over land. stronger anticyclonic circulation at the western branch of the Mascarene high-pressure system enhances the low-level cold air advection by southeast winds,decreases the thickness, and lowers the temperature over a majority of the land in southern Africa. conversely, a weaker Mascarene high, coupled with enhanced cyclonic activity in the southwest Indian Ocean increases low-level warm air advection and increases temperature anomalies over vast regions in southern Africa. The ridging of a closed south Atlantic anticyclone at the southern coast of southern Africa results in colder temperatures near the tip of southern Africa due to enhanced low-level cold air advection by southeast winds. however, when the ridge is weak and westerly winds dominate the southern coast of southern Africa, these areas experience temperature increases. The northward track of the southern hemisphere mid-latitude cyclone, which can be linked to the negative southern Annular Mode, reduces the temperature in the southwestern part of southern Africa. Also, during the analysis period, El Ni?o was associated with temperature increases over the central parts of southern Africa;while the positive Indian Ocean dipole was linked to a temperature increase over the northeastern, northwestern, and southwestern parts of southern Africa.

关键词： temperature circulation types subtropical Indian Ocean dipole southern Annular Mode El Ni?o Indian Ocean dipole Mascarene high south Atlantic anticyclone

A Preliminary comparative study on the centering Algorithms for cassiniIss NAc Images

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Research in Astronomy and Astrophysics 2024年第10期24卷 58-65页

作者： T.Liang Q.-f.Zhang G.-M.Liu W.-h.Zhu c.-s.Wang Department of computer science Jinan UniversityGuangzhou 510632China sino-french Joint Laboratory for Astrometry Dynamics and Space ScienceJinan UniversityGuangzhou 510632China school of computer science Guangdong University of EducationGuangzhou 510303China

Obtaining high precision is an important consideration for astrometric studies using images from the Narrow Angle camera(NAc)of the cassini Imaging science subsystem(Iss).selecting the best centering algorithm is key to enhancing astrometric *** this study,we compared the accuracy of five centering algorithms:Gaussian fitting,the modified moments method,and three point-spread function(Psf)fitting methods(effective Psf(ePsf),PsfEx,and extended Psf(x Psf)from the cassini Imaging central Laboratory for Operations(cIcLOPs)).We assessed these algorithms using 70 Iss NAc star field images taken with cL1 and cL2 filters across different stellar *** ePsf method consistently demonstrated the highest accuracy,achieving precision below 0.03 pixels for stars of magnitude *** to the previously considered best,the modified moments method,the e Psf method improved overall accuracy by about 10%and 21%in the sample and line directions,***,the xPsf model provided by cIcLOPs had lower precision than the ***,the ePsf exhibits an improvement in measurement precision of 23%and 17%in the sample and line directions,respectively,over the *** discrepancy might be attributed to the xPsf focusing on photometry rather than *** findings highlight the necessity of constructing Psf models specifically tailored for astrometric purposes in NAc images and provide guidance for enhancing astrometric measurements using these Iss NAc images.

关键词： methods:analytical techniques:image processing stars:imaging astrometry