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On q-n-gonal Klein Surfaces

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Acta Mathematica Sinica,English Series 2007年第10期23卷 1833-1844页

作者： b.estrada R.A.HIDALGO E.MARTINEZ Departamento de Matemáticas Fundamentales UNEDPaseo Senda del Rey 928040 MadridSpain Departamento de Matemática Universidad Técnica Federico Santa MaríaCasilla 110-V ValparaisoChile

We consider proper Klein surfaces X of algebraic genus p ≥ 2, having an automorphism φ of prime order n with quotient space X/（φ） of algebraic genus q. These Klein surfaces axe called q-n-gonal surfaces and they are n-sheeted covers of surfaces of algebraic genus q. In this paper we extend the results of the already studied cases n ≤ 3 to this more general situation. Given p ≥ 2, we obtain, for each prime n, the （admissible） values q for which there exists a q-n-gonal surface of algebraic genus p. Furthermore, for each p and for each admissible q, it is possible to check all topological types of q-n-gonal surfaces with algebraic genus p. Several examples are given： q-pentagonal surfaces and q-n-gonal bordered surfaces with topological genus g = 0, 1.

关键词： Klein surfaces Riemann surfaces automorphism groups non-Euclidean crystallographic groups

Prospects for ASEAN-China Free Trade Area:A Qualitative and Quantitative Analysis

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China & World Economy 2009年第4期17卷 104-120页

作者： Donghyun Park Innwon Park Gemma Esther b.estrada Economic and Research Department Asian Development Bank Division of International Studies Korea University

The current global financial and economic crisis is giving new life to initiatives that promote closer economic integration among East Asian countries. A significant example is the ASEAN- China Free Trade Area （.4 CFTA）, which is set to come into effect around 2010..4CFTA aims to boost trade between two economies that are partners as well as competitors： ASEAN and China. In the present paper, we use insights from customs union theory in a qualitative analysis considering whether,4CFTA would benefit both sides. We also apply a computable general equilibrium model to perform a quantitative analysis of the same issue. both our qualitative and quantitative analyses provide grounds for guarded optimism regarding A CFTA ＇s prospects as a vehicle for strengthening the economic partnership between ASEAN and China.

关键词： ASEAN China computable general equilibrium model economic integration free trade area

What is the effect of Tribulus terrestris on testicular morphology and sperm production?An experimental study in the rat model

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Asian Journal of Andrology 2024年第1期26卷 67-70页

作者： Marcello Henrique Araujo Da Silva Gabriela Faria buys-Goncalves Joao Henrique Duque Reis estrada Francisco Jose barcellos Sampaio Diogo benchimol de Souza Urogenital Research Unit Rio de Janeiro State UniversityRio de Janeiro 20551-030RJBrazil

The objective of this study was to investigate whether treatment with Tribulus terrestris(Tt)has any impact on the testicular morphology and function in a rodent *** male rats were divided into a control group and a group receiving 100 mg kg^(-1) body weight of Tt *** 4o days of experiment,the animals were submitted to euthanasia;epididymal tail spermatozoa were collected;and spermatozoa concentration,motility,and viability were *** addition,testicles were collected and processed for histomorphometrical *** were compared using the Student's t-test and considered significant when Pbility showed no difference between the ***,testicular weight and volume,seminiferous tubule diameter,tunica propria surface density,seminiferous epithelium surface density,and intertubular compartment surface density were statistically similar between the ***,seminiferous epithelium height and tubular lumen surface density were augmented in animals treated with *** with Tt does not cause a major impact on testicular morphology,promoting only subtle *** difference on spermatozoa parameters was observed.

关键词： morphometry testicle Tribulus terrestris

Photosynthetic Gas Exchange and Nitrogen Assimilation in Green bean Plants Supplied with Two Sources of Silicon

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Phyton-International Journal of Experimental botany 2024年第5期93卷 963-980页

作者： Julio C.Anchondo-Páez Esteban Sánchez Carlos A.Ramírez-estrada Alondra Salcido-Martínez Erick H.Ochoa-Chaparro Department of Plant Physiology Centro de Investigación en Alimentación y DesarrolloCiudad Delicias33089México

beans contain a wide range of vitamins,proteins,calcium,and zinc which make them an important food source for many *** meet the demand for bean production worldwide,large amounts of fertilizers and pesticides are ***,the cost of production and environmental impact *** produce food sustainably,the use of beneficial nutrients such as silicon as a biostimulant has been ***,information about the effect of different sources of silicon on the metabolism of bean plants is *** plants *** were grown in pots for 60 days and the effect of foliar application of silicon nanoparticles and the silicon-based biostimulant Codasilat 4 concentrations(0,1,2,and 4 mM)on total biomass,yield,photosynthetic pigment concentration,photosynthetic activity,stomatal conductance,transpiration rate,chlorophyll fluorescence,and nitrogen assimilation were *** results obtained showed that the supply of silicon at a dose of 1 mM functioned as a biostimulant,favoring gas exchange and nitrogen assimilation within the plant,which stimulated growth and *** results of this research work allowed a better comprehension of the effects of silicon application through silicon nanoparticles and the biostimulant Codasilon the physiology of green bean plants.

关键词： Nanoparticles silicon Phaseolus vulgaris L.

DNA metabarcoding reveals seasonal changes in diet composition across four arthropod-eating lizard species(Phrynosomatidae:Sceloporus)

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Integrative Zoology 2024年第3期19卷 480-495页

作者： Mauricio HERNÁNDEZ Stephanie HEREIRA-PACHECO Antton ALbERDI Aníbal H.DÍAZ DE LA VEGA-PÉREZ Arturo estrada-TORRES Sergio ANCONA Yendi E.NAVARRO-NOYA Doctorado en Ciencias biológicas Centro Tlaxcala de Biología de la ConductaUniversidad Autónoma de TlaxcalaTlaxcalaMexico Estación Científica La Malinche Centro Tlaxcala de Biología de la ConductaUniversidad Autónoma de TlaxcalaTlaxcalaMexico Center for Evolutionary Hologenomics The Globe InstituteUniversity of CopenhagenCopenhagenDenmark Consejo Nacional de Ciencia y Tecnología-Centro Tlaxcala de biología de la Conducta Universidad Autónoma de TlaxcalaTlaxcalaMexico Departamento de Ecología Evolutiva Instituto de EcologíaUniversidad Nacional Autónoma de MéxicoMexico CityMexico Laboratorio de Interacciones bióticas Centro de Investigación en Ciencias BiológicasUniversidad Autónoma de TlaxcalaSan Felipe IxtacuixtlaTlaxcalaMexico

Diet composition and its ecological drivers are rarely investigated in coexisting closely related *** used a molecular approach to characterize the seasonal variation in diet composition in four spiny lizard species inhabiting a mountainous *** metabarcoding revealed that the lizards Sceloporus aeneus,***,***,and *** mostly consumed arthropods of the orders Hemiptera,Araneae,Hymenoptera,and *** terrestrial lizards *** and *** mostly predated ants and spiders,whereas the arboreal–saxicolous *** and saxicolous *** largely consumed grasshoppers and *** taxonomic and phylogenetic diversity of the prey was higher during the dry season than the rainy season,likely because reduced prey availability in the dry season forced lizards to diversify their diets to meet their nutritional *** and phylogenetic composition varied seasonally depending on the species,but only dietary composition varied with *** dietary turnover was greater in *** than in ***,suggesting site-specific seasonal variability in prey availability;no other differences among species were ***,which lives at the highest altitude in our study site,displayed interseasonal variation in diet *** differences were correlated with the species’feeding strategies and elevational distribution,which likely contributed to the coexistence of these lizard species in the studied geographic area and beyond.

关键词： arthropod-eating lizards diet breadth environmental barcoding mountainous ecosystem seasonal dietary shifts

Extended quantum molecular dynamics model predicts new breathing modes in 36Ar bubble nuclei

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Nuclear Science and Techniques 2024年第10期35卷 268-270页

作者： Joseph b.Natowitz Department of Chemistry and Cyclotron Institute Texas A&M UniversityCollege Station

In theoretical investigations of36Ar published by Ge Ren et al.（Phys Lett b 138990,2024）,36Ar bubble nuclei,char acterized by central density depletions,were studied using the extended quantum molecular dynamics *** novel density distributions—microbubble,bubble,and cluster resonances—were identified,each showing distinc spectral signatures in the gamma-ray decay spectrum o the isoscalar monopole ***,the oscillation frequency of the bubble mode mirrors macroscopic bubble dynamics,bridging classical and quantum phenomena in atomic *** exploration of exotic nuclei,driven by advances in large-scale radioactive ion beam facilities,reshapes nuclea physics,particularly as regards the complex structures and behaviors of atomic *** structures and deforma tions[1–3]challenge traditional models.

关键词： bubble quantum dynamics

black hole shadows in Einstein-bel-Robinson gravity

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Chinese Physics C 2024年第5期48卷 272-283页

作者： b.Hamil b.C.Lütfüoğlu Laboratoire de Physique Mathématique et Subatomique Facultédes Sciences ExactesUniversitéConstantine 1ConstantineAlgeria Department of Physics University of Hradec KrálovéRokitanského 6250003 Hradec KrálovéCzechia

Gravity models given by higher-order scalar curvature corrections are believed to bear important consequences. Einstein-bel-Robinson (EbR) gravity with quartic curvature modification motivated Sajadi et al. to explore static spherically symmetric black hole solutions using perturbative methods. In this study, inspired by their work, we investigate AdS black hole shadows in EbR gravity and demonstrate how the gravity parameter alters the energy emission rate. Finally, we address the same problem in the presence of plasma, because the black holes are thought to be surrounded by a medium that changes the geodesic of photons.

关键词： black hole shadows Einstein-bel-Robinson gravity plasma

HVOF-sprayed HAp/S53P4 bG composite coatings on an AZ31 alloy for potential applications in temporary implants

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Journal of Magnesium and Alloys 2024年第1期12卷 345-360页

作者： Carlos A.Poblano-Salas John Henao Astrid L.Giraldo-betancur Paola Forero-Sossa Diego German Espinosa-Arbelaez Jorge A.González-Sánchez Luis R.Dzib-Pérez Susana T.estrada-Moo Idelfonso E.Pech-Pech CIATEQ A.C. Av.Manantiales 23-AParque Industrial Bernardo QuintanaEl MarquésQuerétaro 76246Mexico CONAHCYT-CIATEQ A.C. Av.Manantiales 23-AParque Industrial Bernardo QuintanaEl MarquésQuerétaro 76246Mexico CONAHCYT-Cinvestav Libramiento Norponiente#2000.Fraccionamiento Real de JuriquillaQuerétaro 76230Mexico Universidad Tecnológica de Querétaro Av.Pie de la Cuesta N°2501Querétaro 76148Mexico CIDESI Av.Playa Pie de la Cuesta No 702Col.San PabloQuerétaro 76125Mexico Center for Corrosion Research Autonomous University of CampecheAv.Héroe de Nacozari No.480P.C.24070San Francisco de CampecheCam.Mexico

bioactive thermal spray coatings produced via high-velocity oxygen fuel spray(HVOF)from hydroxyapatite(HAp)and bioactive glasses(bG)have the potential to be employed on temporary implants due to the ability of both HAp and bG to dissolve and promote osseointegration,considering that both phases have different reaction and dissolution rates under in-vitro *** the present work,75%***-25%wt.S53P4 bioactive glass powders were HVOF-sprayed to obtain HAp/S53P4 bG composite coatings on a bioresorbable AZ31 *** study is focused on exploring the effect of the stand-off distance and fuel/oxygen ratio variation as HVOF parameters to obtain stable structural coatings and to establish their effect on the phases and microstructure produced in those *** characterization techniques,such as scanning electron microscopy,X-ray diffraction,and Fourier transform infrared spectroscopy,were employed to characterize relevant structural and microstructural properties of the composite *** results showed that thermal gradients during coating deposition must be managed to avoid delamination due to the high temperature achieved(max 550℃)and the differences in coefficients of thermal *** was also found that both spraying distance and oxygen/fuel ratio allowed to keep the hydroxyapatite as the main phase in the *** addition,in-vitro electrochemical studies were performed on the obtained HAp/S53P4 bG composite coatings and compared against the uncoated AZ31 *** results showed a significant decrease in hydrogen evolution(at least 98%)when the bioactive coating was applied on the Mg alloy during evaluation in simulated body fluid(SbF).

关键词： Coatings Composites Thermal spray Temporary implants Hydrogen evolution

Water Vapor Information from Satellite and Its Applications

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Advances in Atmospheric Sciences 2024年第1期41卷 188-189页

作者： b.J.SOHN School of Earth and Environmental Sciences Seoul National UniversitySeoul 08826Korea

Water vapor is a critical component of the hydrological cycle because it plays a vital role in transporting water from one part of the cycle to *** vapor evaporated from surfaces such as oceans,lakes,and rivers conden... 详细信息

关键词： motion oceans lakes