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Towards efficient strain engineering of 2D materials:A four-points bending approach for compressive strain

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Nano Research 2024年第6期17卷 5317-5325页

作者： Hao Li félix Carrascoso Ana Borrás Gloria P.Moreno francisco J.Aparicio Ángel Barranco Andrés Castellanos Gómez Campus de Cantoblanco Instituto de Ciencia de Materiales de MadridC.Sor Juana Inés de la Cruz328049 MadridSpain Nanotechnology on Surfaces and Plasma Lab Instituto de Ciencia de Materiales de Sevilla(CSIC-Universidad de Sevilla).C/Americo Vespucio 49E-41092 SevilleSpain departamento de física Aplicada I Escuela Politécnica SuperiorUniversidad de Sevillac/Virgen deÁfrica 7E-41011 SevilleSpain

Strain engineering,as a powerful strategy to tune the optical and electrical properties of two-dimensional(2D)materials by deforming their crystal lattice,has attracted significant interest in recent years.2D materials can sustain ultra-high strains,even up to 10%,due to the lack of dangling bonds on their surface,making them ideal brittle *** remarkable mechanical resilience,together with a strong strain-tunable band structure,endows 2D materials with a broad optical and electrical response upon ***,strain engineering based on 2D materials is restricted by their nanoscale and strain quantification *** this study,we have modified a homebuilt three-points bending apparatus to transform it into a four-points bending apparatus that allows for the application of both compressive and tensile strains on 2D *** approach allows for the efficient and reproducible construction of a strain system and minimizes the buckling effect caused by the van der Waals interaction by adamantane encapsulation *** results demonstrate the feasibility of introducing compressive strain on 2D materials and the potential for tuning their optical and physical properties through this approach.

关键词： uniaxial compressive strain polymer encapsulation differential reflectance spectroscopy exciton tunability

Observation about the Classical Electromagnetic Gauge Transformation and Its Quantum Correspondence

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Journal of Modern Physics 2024年第4期15卷 474-479页

作者： Gustavo V. López Jorge A. Lizarraga departamento de física Universidad de Guadalajara Guadalajara Mexico

Using the Landau and symmetric gauges for the vector potential of a constant magnetic field and the quantum problem of a charged particle moving on a flat surface, we show the classical electromagnetic gauge transformation does not correspond to a one-dimensional unitary group transformation U(1) of the wave function for the quantum case. In addition, with the re-examination of the relation between the magnetic field B and its vector potential A, we found that, in order to have a consistent formulation of the dynamics of the charged particle with both expressions, we must have that B=∇×A if and only if B≠0.

关键词： Gauge Transformation Harmonic Oscillator Quantum Hall Effect Electromagnetic Potentials

Metal-modulated epitaxy of Mg-doped Al_(0.80)In_(0.20)N-based layer for application as the electron blocking layer in deep ultraviolet light-emitting diodes

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Journal of Semiconductors 2024年第5期45卷 80-89页

作者： Horacio Irán Solís-Cisneros Carlos Alberto Hernández-Gutiérrez Enrique Campos-González Máximo López-López Optomechatronics Group Tecnológico Nacional de México Campus Tuxtla Gutiérrezcarretera Panamericana 1080C.P.29050Tuxtla GutiérrezChiapasMéxico departamento de física Instituto Nacional de Investigaciones NuclearesCarretera México-Toluca s/nC.P.52750La Marquesa OcoyoacacMéxico departamento de física Centro de Investigación y estudios Avanzados del Instituto Politécnico NacionalAv.Instituto Politécnico Nacional 2508San Pedro ZacatencoGustavo A.Madero07360 Ciudad de MéxicoCDMXMéxico

This work reports the growth and characterization of p-AlInN layers doped with Mg by plasma-assisted molecular beam epitaxy(PAMBE).AlInN was grown with an Al molar fraction of 0.80 by metal-modulated epitaxy(MME)with a thickness of 180 nm on Si(111)substrates using AlN as buffer *** substrate temperatures were used to enhance the incorporation of indium atoms into the alloy without clustering,as confirmed by X-ray diffraction(XRD).Cathodoluminescence measurements revealed ultraviolet(UV)range ***,Hall effect measurements indicated a maximum hole mobility of 146 cm^(2)/(V∙s),corresponding to a free hole concentration of 1.23×10^(19)cm^(−3).The samples were analyzed by X-ray photoelectron spectroscopy(XPS)estimating the alloy composition and extracting the fermi level by valence band ***-doped AlInN layers were studied for use as the electron-blocking layer(EBL)in LED *** varied the Al composition in the EBL from 0.84 to 0.96 molar fraction to assess its theoretical effects on electroluminescence,carrier concentration,and electric field,using SILVACO *** results from this study highlight the importance and capability of producing high-quality Mg-doped p-AlInN layers through *** simulations suggest that an Al content of 0.86 is optimal for achieving desired outcomes in electroluminescence,carrier concentration,and electric field.

关键词： metal-modulated epitaxy AlInN DUV-LED EBL simulation

High CO_(2)permeation using a new Ce_(0.85)Gd_(0.15)O_(2-δ)-LaNiO_(3)composite ceramic–carbonate dual-phase membrane

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Journal of Environmental Sciences 2024年第6期140卷 219-229页

作者： Daniela González-Varela Jfrancisco Gómez-García Gustavo Tavizon Heriberto Pfeiffer Instituto de Investigaciones en Materiales Universidad Nacional Autónoma de MéxicoCd.UniversitariaDel.CoyoacánCP 04510Ciudad de MéxicoMéxico departamento de física y Química Teórica Facultad de QuímicaUniversidad Nacional Autónoma de MéxicoCd.UniversitariaDel.CoyoacánCP 04510Ciudad de MéxicoMéxico 不详

This work shows the synthesis,characterization and evaluation of dense-ceramic membranes made of Ce_(0.85)Gd_(0.15)O_(2-δ)-LaNiO_(3)(CG-LN)composites,where the fluorite-perovskite ratio(CG:LN)was varied as follows:75:25,80:20 and 85:15 wt.%.Supports were initially characterized by XRD,SEM and electrical conductivity(using vacuum and oxygen atmospheres),to determine the composition,microstructural and ionic-electronic conductivity ***,supports were infiltrated with an eutectic carbonates mixture,producing the corresponding dense dual-phase membranes,in which CO_(2)permeation tests were ***,CO_(2)permeation experiments were performed from 900 to 700℃,in the presence and absence of oxygen(flowed in the sweep membrane side).Results showed that these composites possess high CO_(2)permeation properties,where the O_(2)addition significantly improves the ionic conduction on the sweep membrane ***,the GC80-LN20 composition presented the best results due to the following physicochemical characteristics:high electronic and ionic conductivity,appropriate porosity,interconnected porous channels,as well as thermal and chemical stabilities between the composite support and carbonate phases.

关键词： CO_(2)permeation Doped CeO_(2) LaNiO_(3) Impedance Ceramic carbonate membrane

Close Major-merger Pairs at z=0: Star-forming Galaxies with Pseudobulges

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Research in Astronomy and Astrophysics 2024年第5期24卷 35-60页

作者：何川徐聪 Ute Lisenfeld 戴昱方陶陶黄家声王炜余清正 Chinese Academy of Sciences South America Center for Astronomy National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China School of Astronomy and Space Sciences University of Chinese Academy of SciencesBeijing 100049China departamento de física Teórica y del Cosmos Universidad de Granada18071 GranadaSpain Instituto Carlos I de física Téorica y Computacional Facultad de Ciencias18071 GranadaSpain department of Astronomy Xiamen UniversityXiamen 361005China CAS Key Laboratory of Optical Astronomy National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101China

We present a study of star-forming galaxies (SfGs) with pseudobulges (bulges with Sérsic index n2σ) mean of specific star formation rate (sSfR) enhancement (sSfR_(enh)=0.33±0.07 versus sSfR_(enh)=0.12±0.06) and br... 详细信息

We present a study of star-forming galaxies (SfGs) with pseudobulges (bulges with Sérsic index nfrom new aperture photometries in the optical and near-infrared bands (aperture size of 7 kpc) and from the literature,we find that the mean Age of central stellar populations in Spirals with pseudobulges is consistent with that of disky galaxies and is nearly constant against the bulge-to-total ratio (B/T).Paired Spirals have a slightly lower fraction of pure disk galaxies (B/T≤0.1) than their counterparts in the control *** to SfGs with classical bulges,those with pseudobulges have a higher (>2σ) mean of specific star formation rate (sSfR) enhancement (sSfR_(enh)=0.33±0.07 versus sSfR_(enh)=0.12±0.06) and broader scatter (by~1 dex).The eight SfGs that have the highest sSfR_(enh)in the sample all have pseudobulges.A majority (69%) of paired SfGs with strong enhancement (having sSfR more than5 times the median of the control galaxies) have *** Spitzer data show that the pseudobulges in these galaxies are tightly linked to nuclear/circum-nuclear *** SfGs in S+S and in S+E pairs have significantly (>3σ) different sSfR enhancement,with the means of sSfR_(enh)=0.45±0.08 and-0.04±*** find a decrease in the sSfR enhancements with the density of the environment for SfGs with *** a high fraction (5/11) of pseudobulge SfGs in S+E pairs are in rich groups/clusters (loca density N_(1Mpc)≥7),the dense environment might be the cause for their low s SfR_(enh).

关键词： galaxies evolution-galaxies interactions-galaxies star formation-galaxies structure-galaxies bulges-galaxies photometry

Exact solutions for magnetohydrodynamic nanofluids flow and heat transfer over a permeable axisymmetric radially stretching/shrinking sheet

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Chinese Physics B 2024年第2期33卷 108-114页

作者： U.S.Mahabaleshwar G.P.Vanitha L.M.Pérez Emad H.Aly I.Pop department of Studies in Mathematics Davangere UniversityShivagangothriDavangereIndia departamento de f´ısica FACIUniversidad de Tarapac´aCasilla 7DAricaChile department of Mathematics Faculty of EducationAin Shams UniversityRoxyCairoEgypt department of Mathematics Babes-Bolyai University400084 Cluj-NapocaRomania

We report on the magnetohydrodynamic impact on the axisymmetric flow of Al_(2)O_(3)/Cu nanoparticles suspended in H_(2)O past a stretched/shrinked *** the use of partial differential equations and the corresponding thermophysical characteristics of nanoparticles,the physical flow process is *** resultant nonlinear system of partial differential equations is converted into a system of ordinary differential equations using the suitable similarity *** transformed differential equations are solved *** of the magnetic parameter,solid volume fraction and stretching/shrinking parameter on momentum and temperature distribution have been analyzed and interpreted *** skin friction and Nusselt number were also *** addition,existence of dual solution was deduced for the shrinking sheet and unique solution for the stretching ***,Al_(2)O_(3)/H_(2)O nanofluid flow has better thermal conductivity on comparing with Cu/H_(2)O ***,it was found that the first solutions of the stream are stable and physically realizable,whereas those of the second ones are unstable.

关键词： magnetohydrodynamic nanofluid stretching/shrinking sheet axisymmetric flow analytical solution suction/injection

Oligodendroctyes:the forgotten players of diabetes pathophysiology

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Neural Regeneration Research 2024年第11期19卷 2349-2350页

作者： Juan Antonio López-Villodres Beatriz García-Díaz departamento fisiología Humana Histología HumanaAnatomía Patológica y Educación Física y DeportivaFacultad de MedicinaUniversidad de MálagaMálagaSpain UGC Neurociencia.Instituto de Investigación Biomédica de Málaga y Plataforma en Nanomedicina(IBIMA Plataforma Bionand) MálagaSpain

Oligodendrocytes(OLs),glial cells that provide myelin sheaths to axons in the central nervous system(CNS),have a dual ***,this myelin fatty cover around the axons protects the nerves and is crucial for the saltatory propagation of action *** and not less important,OLs provide trophic support to neurons and ***,OL metabolism is important for OL well-being and the proper accomplishment of their functions,and OL metabolism energetics directly affect the energy metabolism of neighboring neurons.

关键词： metabolism nerves myelin

A multi-shot target wheel assembly for high-repetition-rate, laser-driven proton acceleration

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High Power Laser Science and Engineering 2024年第2期 91-98页

作者： J.Pe?as A.Bembibre D.Cortina-Gil L.Martín A.Reija C.Ruiz M.Seimetz A.Alejo J.Benlliure Instituto Galego de física de Altas Enerxías Universidade de Santiago de Compostela Laboratorio Láser de Aceleración y Aplicaciones RIAIDT Universidade de Santiago de Compostela Instituto Universitario de física fundamental y Matemáticas y Dpto.de Didáctica de la Matemática y de las Ciencias Experimentales Universidad de Salamanca Instituto de Instrumentación para Imagen Molecular (I3M) CSIC-Universitat Politècnica de València

A multi-shot target assembly and automatic alignment procedure for laser–plasma proton acceleration at high repetition rate are introduced. The assembly is based on a multi-target rotating wheel capable of hosting more than 5000 targets,mounted on a 3D motorized stage to allow rapid replenishment and alignment of the target material between laser irradiations. The automatic alignment procedure consists of a detailed mapping of the impact positions at the target surface prior to the irradiation that ensures stable operation of the target, which alongside the purpose-built design of the target wheel, enables operation at rates up to 10 Hz. Stable and continuous laser-driven proton acceleration at 10 Hz is demonstrated, with observed cut-off energy stability about 15%.

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Localized-states quantum confinement induced by roughness in CdMnTe/CdTe heterostructures grown on Si(111) substrates

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Journal of Semiconductors 2024年第9期 34-42页

作者： Leonarde do Nascimento Rodrigues Wesley fiorio lnoch Marcos L.f.Gomes Odilon D.D.Couto Jr. Bráulio S.Archanjo Sukarno Olavo ferreira Physics department Federal University of Vi?osa Instituto de física Gleb Wataghin Universidade Estadual de Campinas National Institute of Metrology Quality and Technology (Inmetro) Materials Metrology Division (DIMAT)

This work shows that despite a lattice mismatch of almost 20%, CdMnTe/CdTe/CdMnTe heterostructures grown directly on Si(111) have surprisingly good optical emission properties. The investigated structures were grown by molecular beam epitaxy and characterized by scanning transmission electron microscopy, macro-and micro-photoluminescence. Low temperature macro-photoluminescence experiments indicate three emission bands which depend on the CdTe layer thickness and have different confinement characteristics. Temperature measurements reveal that the lower energy emission band (at 1.48 eV)is associated to defects and bound exciton states, while the main emission at 1.61 eV has a weak 2D character and the higher energy one at 1.71 eV has a well-defined (zero-dimensional, 0D) 0D nature. Micro-photoluminescence measurements show the existence of sharp and strongly circularly polarized (up to 40%) emission lines which can be related to the presence of Mn in the heterostructure. This result opens the possibility of producing photon sources with the typical spin control of the diluted magnetic semiconductors using the low-cost silicon technology.

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