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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

Chromomagnetic dipole moments of light quarks in the bestest little Higgs model

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Chinese Physics C 2024年第10期48卷 125-136页

作者： T.cisneros-Pérez E.Cruz-Albaro A.Y.Ojeda-Castañeda S.E.Solís-núñez Unidad Académica de Ciencias Químicas Universidad Autónoma de ZacatecasApartado Postal C-58598060 ZacatecasMexico Facultad de Física Universidad Autónoma de ZacatecasApartado Postal C-58098060 ZacatecasMexico

In this study,we investigated the anomalous Chromomagnetic Dipole Moment(CMDM),denoted as μ_(q)^(BLHM),of light quarks q=(u,c,d,s,b) within the framework of the Bestest Little Higgs Model(BLHM)as an extension of the Standard Model(SM).Our investigation encompassed novel interactions among the light quarks,heavy quark B,and heavy bosons (W'^(±),H^(±),φ^(±),η^(±))incorporating the extended Cabibbo-Kobayashi-Maskawa(CKM)matrix characteristic of the *** thoroughly explored the permissible parameter space,yielding a spectrum of CMDM values ranging from 10^(-10) to 10^(-3).

关键词： beyond standard model flavor physics chromomagnetic dipole light quarks

Paleoclimate reconstruction during MIS5a based on a speleothem from nerja Cave, Málaga, South Spain

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natural Science 2013年第5期5卷 533-540页

作者： C. jiménez de cisneros E. Caballero Instituto Andaluz de Ciencias de la Tierra. CSIC-UGR. Avd. de las Palmeras 4 18100 Armilla Granada Spain

Speleothems from nerja Cave in southern Spain provide a record during interglacial period MIS5a. Period of speleothem deposition occurred from 70,000 90,000 yr ago. Oxygen (δ18O) and hydrogen (δD) isotope ratios of speleothem and fluid inclusions enable the reconstruction of climatic variability in this region of southern Spain. Fluid inclusions trapped in speleothems represent samples of drip water from which the speleothems grew. The isotopic compositions of cave dripwaters approximate average annual δ18O and δD of precipitation, therefore δ18O can be calculated from D/H of inclusion water using the MWL relationship δD = 8δ18O + 10. The measurements of the δD values of fluid-inclusion water and δ18O values from speleothems have been applied to paleoclimate reconstruction in Southern Spain indicating a colder condition than at present.

关键词： Speleothems Fluid Inclusions Stable Isotope Paleoclimate Spain

Oxygen Isotopic Fractionation in the Kaolinite-Water System during the Synthetic Process

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Journal of Minerals and Materials Characterization and Engineering 2018年第4期6卷 507-516页

作者： E. Caballero C. jiménez de cisneros Instituto Andaluz de Ciencias de la Tierra (UGR-CSIC) Armilla Spain

Oxygen isotope fractionation is studied during the synthesis of kaolinite under controlled conditions of temperature and time. Equilibrium conditions have been established and its relationship with temperature has been studied. Kaolinite was hydrothermally precipitated starting from non-crystalline aluminosilicate gels. The amount of kaolinite obtained increases up to a limited constant value and in all cases coexists with the amorphous starting gels. It can be seen that the data obtained at 48 hours of synthesis can be considered as quasi-equilibrium, since the total isotopic equilibrium has not been reached, only the sample obtained at 24 hours should be discarded for studies in equilibrium. This would allow us, with the samples obtained at 720 hours, to try to establish a relationship between isotopic fractionation and temperature, provided that we know the water in equilibrium with the synthesized kaolinite. Two equations have been obtained that show correlation coefficients with a high statistical significance.

关键词： Oxygen Isotopic Fractionation Kaolinite-Water System Isotopic Equilibrium

Foaming supramolecular surfactants for gas mobility control in naturally fractured carbonate reservoirs at high temperature,salinity,and hardness

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Petroleum Science 2022年第6期19卷 3134-3148页

作者： Enrique Soto-Castruita Raúl Hern andez-Altamirano Eduardo Buenrostro-González Erick-Emanuel Luna-Rojero Sung Jae Ko-Kim Violeta-Yasmín Mena-Cervantes Mirna Pons-jiménez Jorge-Francisco Ramírez-Pérez David-Aaσn nieto-Alvarez Ricardo Cerón-Camacho Jos e-Ernesto Parra Raúl Oviedo-Roa Jos e-Manuel Martínez-Magadán Rodolfo cisneros-Dévora Luis-S.Zamudio-Rivera Instituto Mexicano del Petr oleo Eje Central Lazaro Cardenas Norte 152Col.San Bartolo AtepehuacanCiudad de Mexico07730Mexico COnACy T-Instituto Mexicano del Petroleo Eje Central Lazaro Cardenas Norte 152Col.San Bartolo AtepehuacanCiudad de Mexico07730Mexico Centro Mexicano para la Produccion mas Limpia Instituto Politecnico NacionalAvenida Acueducto s/nCol.La Laguna TicomanCiudad de Mexico07340Mexico Centro de Tecnologías para Exploracion y Produccion Camino de Terracería 800Col.San Jose NovilleroBoca delRíoVeracruz94286Mexico

Oil production and mainte nance are essential issues in naturally fractured reservoirs because they are the largest and most productive on ***,they present early water and gas channeling but could be remediated by using foaming agents to control these phenomena through blocking channeling *** Mexico these reservoirs have pressure up to 5,500 psi,high temperature up to 200℃,salinity up to400,000 ppm,and hardness up to 250,000 ppm;due to these thermodynamic conditions,there has been no available technology to form stable enough *** this work,a foaming supramolecular surfactant with the capability to chelate Ca^(2+)ions is *** a result,surfactant monomers are bridged by captured Ca^(2+)cations leading to the formation of high-molecular-weight oligomers,which significantly increment the viscosity of the solution improving the foam stability,and since at this manner the Ca2+cations are no longer available to precipitate as components of solid salts,the foaming supramolecular surfactant also performs as *** observations are explained through quantum theoretical *** foam is stable,effectively blocking the gas channels,whereas in presence of oil the foam is broken leading the oil to pass into the *** characteristic rheological properties of the foam allow its injection into the formation at a range of flow rates,foam qualities,and shear stress to achieve the flooding and the blocking of a variety of fractured carbonate formations,and the change of the wettability of the matrix,which is a desirable behavior in a huff and puff process,as reported in a previous publication about a successful pilot test of this foam.

关键词： Calcium chelation Foaming composition Supramolecular surfactant Molecular design Gas mobility control Flow assurance Improved oil recovery Conformance control

Mechanical properties of the A356 aluminum alloy modified with La/Ce

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Journal of Rare Earths 2013年第8期31卷 811-816页

作者： E. Aguirre-de la Torre R. Pérez-Bustamante J. Camarillo-cisneros C.D. Gómez-Esparza H.M. Medrano-Prieto R. Martínez-Sánchez Advanced Materials Research Center (CIMAV) National Laboratory of Nanotechnology

The research of rare earths for the synthesis of materials with improved mechanical performance is of great interest when they are considered for potential applications in the automotive industry. In this regard, the effect on the mechanical properties and microstmcture of the automotive A356 aluminum alloy reinforced with 0.2 （wt.%） AI-6Ce-3La （ACL） was investigated. The ACL was added to the melted A356 alloy in the as-received condition and processed by mechanical milling. In the second route, the effect of the ACL processed by mechanical milling and powder metallurgy techniques was investigated, and compared with the results ob- tained from the A356 alloy strengthened with ACL in the as-received condition. Microstmctural properties were evaluated by means of X-ray diffraction in order to observe the solubility of Ce/La in the A1 matrix. In addition, electron microscopy was employed in or- der to investigate the effect of milling time on the size and morphology of La/Ce phase under milling process. Mechanical properties of the A356 alloy modified with ACL were measured by hardness and tensile test. For comparison unmodified specimens of the A356 were characterized according to the previous procedure. The microstructural and mechanical characterization was carried out in specimens alter solution and artificial aging. Observations in scanning electron microscopy indicated a homogeneous dispersion of La/Ce phases by using both routes; however, mechanical results, in the modified A356 alloy with the ACL in the as-received condi- tion, showed an improvement in the mechanical performance of the A356 alloy over that reinforced with the ACL mechanically milled.

关键词： A356 rare earths mechanical milling mechanical properties

Use of carbon nanotubes for strain and damage sensing of epoxy-based composites

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International Journal of Smart and nano Materials 2012年第2期3卷 152-161页

作者： J.Rams M.Sánchez A.Ureña A.jiménez-Suárez M.Campo A.Güemes Materials Science and Engineering Rey Juan Carlos UniversityTulipan s/nMostoles28933 MadridSpain ETSIA Universidad Politécnica de MadridPza.de Cardenal Cisneros 328040 MadridSpain

The interest in structural health monitoring of carbon fiber-reinforced polymers using electrical methods to detect damage in structures is growing because once the material is fabricated the evaluation of strain and damage is simple and *** order to obtain the conductivity,the polymer matrix must be conductive and the use of nanoreinforcement seems to be the most feasible *** this work,the behavior of nanoreinforced polymer with carbon nanotubes(CnTs)and composites with glass and carbon fibers with nanoreinforced matrices was *** composites were evaluated in tensile tests by simultaneously measuring stress,strain and *** elastic deformation,a linear increase in resistance was observed and during fracture of the composite fibers,stronger and discontinuous changes in the resistivity were *** other factors,the percentage of nanotubes incorporated in the matrix turned out to be an important factor in the sensitivity of the method.

关键词： carbon nanotube nanoreinforcement structural health monitoring strain sensing carbon fiber

Selective reductive coupling of nitro aliphatic compounds with aldehydes in hydrogen using gold catalyst

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Chinese Journal of Catalysis 2016年第10期37卷 1756-1763页

作者： Larisha cisneros Pedro Serna Avelino Corma 瓦伦西亚理工大学-西班牙国家研究委员会化学工程研究所西班牙瓦伦西亚46022 埃克森美孚研究与工程有限公司企业战略研究美国新泽08801

nitrones were synthesized in good yields directly from nitro aliphatic compounds, aldehydes, and H2 using highly dispersed gold nanoparticles on titania, The high selectivity for nitrone synthesis contrasts with the platinum supported on carbon and corresponds to an increase from roughly 50% to 90%, The catalytic performance is tuned by precise control of the structure of the active sites, the characteristics of the support and reaction conditions.

关键词： Gold catalystnitro compoundCascade-type reactionHydrogenationnitrone

Altitude as environmental filtering influencing phylogenetic diversity and species richness of plants in tropical mountains

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Journal of Mountain Science 2023年第2期20卷 285-298页

作者： GALVÁn-cisneros Carlos M. VILLA Pedro M. COELHO Alex J.P. CAMPOS Prímula V. MEIRA-nETO João A.A. Laboratory of Ecology and Evolution of Plants Departamento de Biologia VegetalUniversidade Federal de ViçosaViçosaMG36570-900Brazil Botany Gradute Program Universidade Federal de ViçosaViçosaMG36570-900Brazil

Elucidating how multiple factors affect biodiversity and plant community assembly is a central issue in ecology,especially in vulnerable ecosystems such as tropical *** studies are more relevant in global warming scenarios that induce the upward displacement of plant species towards reduced habitats and hostile environments in tropical *** study aimed to analyze how altitude affects taxonomic and phylogenetic diversity in plant communities of tropical ***,we tested if(i)increased altitude works as an environmental filtering promoting decreased species richness,decreased phylogenetic diversity,and increased phylogenetic clustering in these tropical mountains;and if(ii)plant communities of high altitude in tropical mountains are also result of recent diversification with plant species recently split shortening phylogenetic distances between closest related *** tested effects of altitude on species richness and phylogenetic metrics using linear mixed-effects *** Haleakala presented 114 species,Mount Kilimanjaro presented 231 species and Mount Purace presented 280 *** found an environmental filtering effect with increasing altitude causing phylogenetic clustering,decreased phylogenetic diversity and decreased species *** decreasing phylogenetic distances between closest relatives are congruent with neo-endemics,suggesting recent plant diversification in high altitudes of tropical mountains,possibly driven by geographic isolation and environmental *** of global warming should be monitored in tropical mountains focusing on distribution shifts.

关键词： Tropical mountains Global warming Environmental filtering Phylogenetic ecology Assembly rules Conservation Mountaintop vegetation