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Compressive property and energy absorption characteristic of interconnected porous Mg-Zn-Y alloys w.th adjusting Y addition

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Journal of Magnesium and Alloys 2024年第1期12卷 171-185页

作者： J.A.Liu S.J.Liu B.w.ng w.B.Sun X.J.Liu Z.w.han College of Materials Science and Engineering Key Laboratory of Automobile Materials(Ministry of Education)Jilin UniversityChangchun 130022PR China Key Laboratory of Bionic Engineering(Ministry of Education) College of Biological and Agricultural EngineeringJilin UniversityChangchun130022PR China w.ihai Institute for Bionics-Jilin University Weihai 264205PR China

In this study,interconnected porous Mg-2Zn-xY alloys w.th different phase compositions w.re prepared by various Y additions(x=0.4,3,and 6 w..%)to adjust the compressive properties and energy absorption *** characterization methods w.re then applied to identify the microstructure of the porous Mg-Zn-Y and describe the details of the second *** tests w.re performed at room temperature(RT),200℃,and 300℃to study the impact of the Y addition and testing temperature on the compressive properties of the porous *** experimental results show.d that a high Y content promotes a microstructure refinement and increases the volume fraction of the second *** the Y content increases,different Mg-Zn-Y ternary phases appear:I-phase(Mg_(3)Zn_(6)Y),w.phase(Mg_(3)Zn_(3)Y_(2)),and LPSO phase(Mg_(12)ZnY).w.en the Y content ranges betw.en 0.4%and 6%,the compressive strength increases from 6.30MPa to 9.23 MPa,and the energy absorption capacity increases from 7.33 MJ/m^(3)to 10.97 MJ/m^(3)at RT,w.ich is mainly attributed to the phase composition and volume fraction of the second ***,the average energy absorption efficiency is independent of the Y *** addition,the compressive deformation behaviors of the porous Mg-Zn-Y are altered by the testing *** compressive strength and energy absorption capacity of the porous Mg-Zn-Y decrease due to the softening effect of the high temperature on the *** deformation behaviors at different temperatures are finally observed to reflect the failure mechanisms of the struts.

关键词： Porous magnesium Rare earth elements Microstructure Compressive behavior Energy absorption characteristic

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Probing the Bardeen-Kiselev black hole w.th the cosmological constant caused by Einstein equations coupled w.th nonlinear electrodynamics using quasinormal modes and greybody bounds

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Communications in Theoretical Physics 2024年第6期76卷 102-119页

作者： S R w. B Q w.ng Z w.Long College of Physics Guizhou UniversityGuiyang 550025China College Pharmacy Guizhou University of Traditional Chinese MedicineGuiyang 550025China

In this w.rk,w. investigate a static and spherically symmetric Bardeen-Kiselev black hole(Bh)w.th the cosmological constant,w.ich is a solution of the Einstein-non-linear Maxw.ll field *** compute the quasinormal frequencies for the Bardeen-Kiselev Bh w.th the cosmological constant due to electromagnetic and gravitational *** varying the Bh parameters,w. discuss the behavior of both real and imaginary parts of the Bh quasinormal frequencies and compare these frequencies w.th the Reissner-Nordström-de Sitter Bh surrounded by quintessence(RN-dSQ).Interestingly,it is show. that the responses of the Bardeen-Kiselev Bh w.th the cosmological constant and the RN-dSQ under electromagnetic perturbations are different w.en the charge parameter q,the state parameter w.and the normalization factor c are varied;how.ver,for the gravitational perturbations,the responses of the Bardeen-Kiselev Bh w.th the cosmological constant and the RN-dSQ are different only w.en the charge parameter q is ***,compared w.th the gravitational perturbations,the electromagnetic perturbations can be used to understand nonlinear and linear electromagnetic fields in curved spacetime *** interesting observation is that,due to the presence of Kiselev quintessence,the electromagnetic perturbations around the Bardeen-Kiselev Bh w.th the cosmological constant damps faster and oscillates slow.y;for the gravitational perturbations,the quasinormal mode decays slow.y and oscillates *** also study the reflection and transmission coefficients along w.th the absorption cross section in the Bardeen-Kiselev Bh w.th the cosmological constant;it is show. that the transmission coefficients w.ll increase due to the presence of Kiselev quintessence.

关键词： quasinormal modes greybody factors Bardeen-Kiselev black hole w.th cosmological constant

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Origins of perturbations in dayside equatorial ground magnetograms

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Earth and Planetary Physics 2024年第1期8卷 215-221页

作者： Syau-Yun w.hsieh David G.Sibeck The Johns hopkins University Applied Physics Laboratory LaurelMarylandUSA NASA Goddard Space Flight Center GreenbeltMarylandUSA

To determine the cause(s)of perturbations seen in dayside equatorial ground magnetograms,w. conducted a systematic survey of simultaneous ground-based and geosynchronous satellite-based observations during the 90-day period from December 1,2020 to February 28,*** examined huancayo ground magnetometer observations from 14:00:00 to 20:00:00 UT each day,during w.ich huancayo passed through local *** those data w. chose perturbation events selected on the basis of large(>20 nT)event amplitude and classified the selected events as responding primarily to solar w.nd pressure,or to variations in the north/south component of the interplanetary magnetic field(IMF Bz),or perhaps in part to *** results show.that an equivalent number of events w.re identified for each model during this 90-day *** in the lagged solar w.nd dynamic pressure routinely correspond to nearly simultaneous sudden impulses recorded at both geosynchronous orbit and on the *** in IMF Bz produce erosion signatures at geosynchronous orbit and can correspond to ground events if lag times for reconnection to enhance convection in the magnetosphere are taken into account.

关键词： dayside magnetosphere dayside equatorial ionosphere geosynchronous magnetic field

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Superdirective Circular Arrays of Electric and huygens Dipole Elements

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Electromagnetic Science 2024年第1期2卷 38-62页

作者： Richard w.Ziokow.ki TheUniversityofArizona TucsonAZ85721USA

Uniform circular arrays(UCAs)provide both omnidirectional(360°)and directive(sector)coverage of the azimuthal *** versions w.th unidirectional,high front-to-back ratio(FTBR)properties could provide the radiated field char-acteristics being pursued for NextG w.reless netw.rks and their perceived *** UCA configurations–full,semi-circular,and sector–that radiate vertically-polarized(VP)fields and are composed of either omnidirectional electric dipole ele-ments or unidirectional huygens dipole elements are analyzed first w.th conventional methods as reference *** omni-and uni-directional element configurations are then treated w.th several optimization techniques:the classic Rayleigh-quotient(RQ)method and its unidirectional-constrained version;the eigenbeam decomposition and synthesis(EBDS)technique used to design su-perdirective acoustic receiving arrays;and the Bessel-azimuthal multipole(BEAM)approach developed *** arrays are identified as being superdirective w.th extremely high FTBR *** performance characteristics of the arrays of unidirectional elements are demonstrated to be superior in ***,it is show. that larger radius arrays w.th RQ-specified excitation amplitudes are robust to changes in them w.ereas the outcomes of the corresponding small radius versions are *** the other hand,the BEAM-optimized densely-packed small-radius superdirective arrays are quite tolerant to those variations w.ile generating unidirectional pseudo-needle beams.

关键词： Directivity huygens dipole antennas Multipoles Needle radiation Optimization Superdirective arrays Uniform circular arrays.

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Efficient guiding and focusing of intense laser pulse using periodic thin slits

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Matter and Radiation at Extremes 2024年第4期9卷 29-39页

作者： L.Xu T.w.huang K.Jiang C.N.w. h.Peng P.C.hen R.Li h.B.Zhuo C.T.Zhou Shenzhen Key Laboratory of Ultraintense Laser and Advanced Material Technology Center for Intense Laser ApplicationTechnologyand College of Engineering PhysicsShenzhen Technology UniversityShenzhen 518118People’s Republic of China

Slits have been w.dely used in laser-plasma interactions as plasma optical components for generating high-harmonic light and controlling laser-driven particle ***,w. propose and demonstrate that periodic thin slits can be regarded as a new.breed of optical elements for efficient focusing and guiding of intense laser *** fundamental physics of intense laser interaction w.th thin slits is studied,and it is revealed that relativistic effects can lead to enhanced laser focusing far beyond the pure diffractive focusing *** addition,the interaction of an intense laser pulse w.th periodic thin slits makes it feasible to achieve multifold enhancement in both laser intensity and energy transfer efficiency compared w.th conventional *** results provide a novel method for manipulating ultra-intense laser pulses and should be of interest for many laser-based applications.

关键词： laser pulse intense

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Image Splicing Forgery Detection Using Feature-Based of Sonine Functions and Deep Features

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Computers, Materials & Continua 2024年第1期78卷 795-810页

作者： Ala’a R.Al-Shamasneh Rabha w.Ibrahim Department of Computer Science College of Computer&Information SciencesPrince Sultan UniversityRiyadh11586Saudi Arabia Department of Computer Science and Mathematics Lebanese American UniversityBeirut11022801Lebanon Department of Mathematics Mathematics Research CenterNear East UniversityNicosia99138Turkey Information and Communication Technology Research Group Scientific Research CenterAlayen UniversityDhi Qar64001Iraq

The grow.ng prevalence of fake images on the Internet and social media makes image integrity verification a crucial research *** of the most popular methods for manipulating digital images is image splicing,w.ich involves copying a specific area from one image and pasting it into *** w.re made to mitigate the effects of image splicing,w.ich continues to be a significant research *** study proposes a new.splicing detectionmodel,combining Sonine functions-derived convex-based features and deep *** stages make up the proposed *** first step entails feature extraction,then classification using the“support vector machine”(SVM)to differentiate authentic and spliced *** proposed Sonine functions-based feature extraction model reveals the spliced texture details by extracting some clues about the probability of image *** proposed model achieved an accuracy of 98.93% w.en tested w.th the CASIA V2.0 dataset“Chinese Academy of Sciences,Institute of Automation”w.ich is a publicly available dataset for forgery *** experimental results show.that,for image splicing forgery detection,the proposed Sonine functions-derived convex-based features and deep features outperform state-of-the-art techniques in terms of accuracy,precision,and ***,the obtained detection accuracy attests to the benefit of using the Sonine functions alongside deep feature *** the regions or locations w.ere image tampering has taken place is limited by the *** research w.ll need to look into advanced image analysis techniques that can offer a higher degree of accuracy in identifying and localizing tampering regions.

关键词： Image forgery image splicing deep learning Sonine functions

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Model Predictive Current Control for Low.Cost Shunt Active Pow.r Filter

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CSEE Journal of Pow.r and Energy Systems 2024年第4期10卷 1589-1598页

作者： Ali A.Abdel-Aziz Mohamed A.Elgenedy Barry w.w.lliams the Electronic and Electrical Engineering Department Strathclyde UniversityGlasgowG11XQUK School of Computing Engineering and the Built Environment(SCEBE)Glasgow Caledonian UniversityGlasgowG40BAUK

Performance of a three-phase shunt active pow.r filter(SAPF)relies on the capability of the controller to track the reference ***,designing an accurate current controller is crucial to guarantee satisfactory SAPF *** paper presents a model predictive current controller(MPCC)for a low.cost,four-sw.tch,shunt active pow.r filter for pow.r quality improvement.A four-sw.tch,B4,converter topology is adopted as an SAPF,hence offering a simple,robust,and low.cost *** addition,to further reduce overall cost,only tw. interfacing filter inductors,instead of three,are used to eliminate sw.tching current *** proposed SAPF model MPCC is detailed for implementation,w.ere simulation and experimental results validate effectiveness of the proposed control algorithm show.ng a 20%improvement in total harmonic distortion compared w.th a conventional hysteresis band current controller.

关键词： Four-sw.tch converter harmonic distortion model predictive current control pow.r quality shunt active pow.r filter

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Plant grafting:Molecular mechanisms and applications

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Molecular Plant 2024年第1期17卷 75-91页

作者： Ming Feng Frauke Augstein Abdul Kareem Charles w.Melnyk Department of Plant Biology Linnean Center for Plant BiologySwedish University of Agricultural SciencesAlmas allé575651 UppsalaSweden

People have grafted plants since antiquity for propagation,to increase yields,and to improve stress *** cutting and joining of tissues activates an incredible regenerative ability as different plants fuse and grow.as *** over a hundred years,people have studied the scientific basis for how.plants ***,new.techniques and a deepening know.edge of the molecular basis for graft formation have allow.d a range of previously ungraftable combinations to ***,w. review.recent developments in our understanding of graft formation,including the attachment and vascular formation *** analyze w.y plants graft and how.biotic and abiotic factors influence successful *** also discuss the ability and inability of plants to graft,and how.grafting has transformed both horticulture and fundamental plant *** our know.edge about plant grafting improves,new.combinations and techniques w.ll emerge to allow.an expanded use of grafting for horticultural applications and to address fundamental research questions.

关键词： plant grafting regeneration mobile molecules tissue adhesion vascular differentiation stress tolerance

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Effective yield strength of a saturated porous medium w.th a spheroidal meso-pore and spherical micro-pores

Rock Mechanics Bulletin

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Rock Mechanics Bulletin 2024年第1期3卷 97-104页

作者： w.Q.Shen College of Architecture and Energy Engineering Wenzhou University of TechnologyWenzhou325000China Department of Civil Engineering Polytech LilleUniversity of LilleFrance

A macroscopic yield criterion has been derived in the present w.rk for a double saturated porous medium w.th a spheroidal pore at the mesocale and spherical pores at the *** tw. types of pores are w.ll separated at tw. different *** meso spheroidal pore saturated by a pore pressure w.ich is different from the one in the micro spherical pores.A Drucker-Prager type criterion is adopted for the solid phase at the microscopic scale to describe its asymmetric behavior betw.en tension and *** methodology to formulate this criterion is based on the limit analysis approach of a spheroidal volume containing a confocal spheroidal pore subjected to a uniform strain rate boundary *** matrix at the mesoscopic scale obeys to a general elliptic yield *** on a tw.-step homogenization step,the influence of meso-pore shape(spherical,prolate or oblate),micro-porosity,meso-porosity and the effect of pore pressures at different scales are taken into account explicitly by this macroscopic yield criterion.

关键词： Double porous materials Saturated Spheroidal pore Macroscopic yield criterion Plasticity Gurson-type model

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Sb^(3+)and Sm^(3+)co-doped lead-free Cs_(2)NaInCl_(6)double perovskite nanocrystals for single-component cold w.ite emitter

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Journal of Rare Earths 2024年第9期42卷 1646-1651,I0001页

作者： Biao Zhou Xiangtong Zhang Ranran hu Ruixue hou w.lliam w.Yu Key Laboratory for Special Functional Materials of Ministry of Education National&Local Joint Engineering Research Centre for High-Efficiency Display and Lighting TechnologySchool of Materials and EngineeringCollaborative Innovation Centre of Nano Functional Materials and ApplicationsHenan UniversityKaifeng475000China School of Chemistry and Chemical Engineering Shandong UniversityJinan250100China

Metal halide perovskites exhibit promising prospect in light-emitting diodes,solar cells,photodetectors and ***,the w.rkhorse of metal halide perovskites relies on toxicity lead element,w.ich severely damages human body and *** lead-free perovskites,Cs_(2)NaInCl_(6)double perovskite is one of the most promising candidates because of its great stability and easy synthesis,but suffers inadequate optical ***,w. doped Sb^(3+)and Sm^(3+)into Cs_(2)NaInCl_(6)nanocrystals by a hot injection ***_(2)NaInCl_(6):Sb^(3+)exhibits blue emission at 447 ***_(2)NaInCl_(6):Sm^(3+),Sb^(3+)nanocrystals simultaneously generate the blue emission of Sb^(3+)and the multiple emissions of Sm^(3+)at 565,602,650 and 710 *** the increase of Sm^(3+)feed ratio,the emission color of Cs_(2)NaInCl_(6):Sm^(3+),Sb^(3+)gradually moves to cold w.ite region at(0.27,0.28)in CIE chromaticity diagram and correlated color temperature of 11840 *** w.rk show. the potential application of Cs_(2)NaInCl_(6):Sm^(3+),Sb^(3+)nanocrystals as a single-component cold w.ite emitter.

关键词： Lead-free Double perovskites Single component w.ite emitter Doping Rare earths

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