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Ontogenetic transition in leaf traits: a new cost associated with the increase in leaf longevity

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Journal of Plant Ecology 2014年第6期7卷 567-575页

作者： Sonia Mediavilla Maria Herranz Patricia González-Zurdo Alfonso Escudero departamento de Ecología Facultad de BiologíaUniversidad de SalamancaSalamanca 37071Spain

Aims Recent work has identified a worldwide‘economics’spectrum of correlated leaf traits that mainly reflects the compromises between maximizing leaf longevity and short-term ***,during the early stages of tree growth different species tend to exhibit a common strategy,because competition for soil water and nutrients forces the maximization of short-term productivity owing to the need for rapid growth during the most vulnerable part of the tree’s life ***,our aim here was to compare the variations that occur during ontogeny in the different leaf traits(morphology and leaf chemical composition)of several coexisting Mediterranean woody species differing in their leaf life spans and to test our hypothesis that tree species with a long leaf life span should exhibit larger shifts in leaf characteristics along *** Six Mediterranean tree species differing in leaf life span,selected from three plots located in central-western Spain,were studied during three growth stages:seedlings,juveniles and mature *** life span,leaf morphology(leaf area,dry weight,thickness and mass per unit area)and chemical composition(N and fibre con-centrations)were measured in all six *** magnitude of the ontogenetic changes in the different traits was estimated and related to the mean leaf longevity of the different *** Findings Along ontogeny,strong changes were observed in all variables *** early growth stages showed lower leaf thickness,leaf thickness and mass per unit area and N,cellulose and hemi-cellulose concentrations than mature trees,but a higher lignin ***,these changes were especially marked in species with a longer leaf life span at *** dif-ferences in leaf life span,leaf morphology and chemical com-position were stronger at the mature stage than at the seedling *** conclude that greater plasticity and more intense strat-egy shifts along ontogeny are necessarily associ

关键词： leaf morphology leaf N concentration fibre content Pinus Quercus tree age class

A Characterization of Linearly Semisimple Groups

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Acta Mathematica Sinica,English Series 2011年第1期27卷 185-192页

作者： Amelia ALVARE Z Pedro SANCHO Carlos SANCHO departamento de Matemdticas Universidad de Extremadura Avenida de Elvas s/n 06006 Badajoz Spain departamento de Matemdticas Universidad de Salamanca Plaza de la Merced 1-4 37'008 Salamanca Spain

Let G -- Spec A be an affine K-group scheme and A = （w ∈ A＊： dimK A＊-w 〈 ∞, dimK w. A＊〈 ∞}. Let （-, -）： A＊ × A → K, （w, w）：= tr（ww）, be the trace form. We prove that G is linearly reductive if... 详细信息

Let G -- Spec A be an affine K-group scheme and A = （w ∈ A＊： dimK A＊-w 〈 ∞, dimK w. A＊〈 ∞}. Let （-, -）： A＊ × A → K, （w, w）：= tr（ww）, be the trace form. We prove that G is linearly reductive if and only if the trace form is non-degenerate on A＊.

关键词： Linearly reductive group trace form Pontrjagin's duality

Molecular and compact four-quark states

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Chinese Physics C 2010年第9期34卷 1290-1293页

作者： A.Valcarce J.Vijande departamento de Física Fundamental Universidad de Salamanca departamento de Física Atómica Molecular y NuclearUniversidad de Valencia (UV) and IFIC (UV-CSIC)

We study charmonium （ccnn）,bottomonium （b bnn） and exotic （ccnn and bbnn） four-quark states by means of a standard non-relativistic quark potential *** look for possible bound *** them we are able to distinguish... 详细信息

关键词： tetraquarks quark-models charmonium exotics

Spectrophotometric determination of the formation constants of Calcium(Ⅱ) complexes with 1,2-ethylenediamine,1,3-propanediamine and 1,4-butanediamine in acetonitrile

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Green Energy & Environment 2017年第1期2卷 51-57页

作者： Jacqueline González González Mónica Nájera-Lara Varinia López-Ramírez Juan Antonio Ramírez-Vázquez José J.N.Segoviano-Garfias Programa de Maestría en Biociencias División de Ciencias de la Vida (DICIVA) Universidad de Guanajuato Campus Irapuato-Salamanca Colegio del Nivel Medio Superior de salamanca(ENMS) departamento de Ingeniería Bioquímica Instituto Tecnológico Superior de Irapuato (ITESI) departamento de Ciencias Ambientales División de Ciencias de la Vida (DICIVA) Universidad de Guanajuato Campus Irapuato-Salamanca

In this work, with the purpose to explore the coordination chemistry of calcium complexes which could work as a partial model of manganese-calcium cluster, a spectrophotometric study to evaluate the stability of the complexes: Calcium(Ⅱ)-1,2-ethylendiamine, Calcium(Ⅱ)-1,3-propanediamine and Calcium(Ⅱ)-1,4-butanediamine in acetonitrile, were carried on. By processing the spectrophotometric data with the HypSpec program allows the determination of the formation constants. The logarithmic values of the formation constants obtained for Calcium(Ⅱ)-1,2-ethylendiamine, Calcium(Ⅱ)-1,3-propanediamine and Calcium(Ⅱ)-1,4-butanediamine were log β_(110) = 4.69, log β_(110)= 5.25 and log β_(110) = 4.072, respectively.

关键词： Calcium(Ⅱ)complexes Solution equilibria Artificial photosynthesis Absorbance molar Speciation

Role of hyperfine mixing in b→c semileptonic decays of doubly-heavy baryons

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Chinese Physics C 2010年第9期34卷 1488-1490页

作者： C.Albertus E.Hernández J.Nieves departamento de Física Fundamental e IUFFyM Universidad de Salamanca Instituto de Física Corpuscular (IFIC) Centro Mixto CSIC-Universidad de ValenciaInstitutos de Investigación de Paterna

We analyze the effects of hyperfine mixing in b → c semileptonic decays of doubly heavy *** qualitatively confirm the results by *** and *** in ***.A,2009,24： 2401– 2413,finding that mixing has a great impact on those ***,predictions without mixing differ by a factor of 2 and this discrepancy translates to the mixed case where large differences in decay widths are observed between the two calculations.

关键词： doubly-heavy baryons semileptonic decay hyperfine mixing

Is X(3872) a bound state?

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Chinese Physics C 2019年第12期43卷 115-120页

作者： Pablo G.Ortega Enrique Ruiz Arriola Grupo de Fisica Nuclear and Instituto Universitario de Fisica Fundamental y Matematicas(IUFFyM) Universidad de SalamancaE-37008 SalamancaSpain departamento de Fisica Atomica Molecular y Nuclear and Instituto Carlos I de Fisica Teorica y ComputacionalUniversidad de GranadaE-18071 GranadaSpain

All existing experimental evidence for the bound state nature of X(3872)relies on observing its decay products,which are measured with a finite experimental mass resolution that is typically△m≥2 MeV,and much larger than its alleged binding energy,BX=0.00(18)*** the other hand,we have found recently that there is a clear cancellation in the 1^++channel of the invariant DD^*mass around the threshold between continuum and the bound *** is very much like a similar cancellation in the proton-neutron continuum with the deuteron in the 1^++*** on comparative fits with a common Tsallis distribution of the experimental cross-sections for prompt production of deuterons and X(3872)in pp collisions with a finite pT,we find a strong argument for questioning the bound state nature of this state,which also suggests that the large observed production rate could be consistent with a half-bound state.

关键词： charmonium molecular states particle production Tsallis distribution

NHC-catalysed[3+2]-asymmetric annulation between pyrazolin-4,5-diones and enals:synthesis of novel spirocyclic pyrazolone γ-butyrolactones and computational study of mechanism and stereoselectivity

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Organic Chemistry Frontiers 2022年第2期9卷 420-427页

作者： Marta Gil-Ordonez Alicia Maestro Pablo Ortega Pablo G.Jambrina Jose M.Andres GIR-SintACat-Instituto Universitario CINQUIMA y departamento de Química Orgánica Facultad de CienciasUniversidad de ValladolidPaseo Belén 747011 ValladolidSpain departamento de Química Física University of Salamanca37008 SalamancaSpain

Chiral pyrazolones with a spirocyclic centre at the C4-position are widely found in a large family of medically relevant *** recent years,organocatalysis,particularly that performed with quiral N-heterocyclic carbenes(NHCs),has allowed the enantioselective synthesis of these spirocyclic compounds despite its inherent *** this work,we describe the fully diastereo-and highly enantioselective synthesis of novel spirocyclic pyrazolone γ-butyrolactones via NHC-catalysed[3+2]annulation reaction of enals and 1H-pyrazol-4,*** understand the catalytic mechanism and origin of stereoselectivity,electronic structure calculations were carried *** considering various pathways,we concluded that the stereoselectivity-determining step is the formation of the lactone that proceeds after addition of the NHC derived homoenolate to the electrophilic carbonyl group of pyrazolin-4,*** calculations predict that the free energy barrier is lower for the(RS)product,which is also the main product experimentally obtained.

关键词： synthesis spiro mechanism

Single droplet drying of detergents:Experimentation and modelling

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Particuology 2021年第5期19卷 35-47页

作者： Borja Hernandez Rosa Mondragon Mark A.Pintoa Leonor Hernandez J.Enrique Julia Juan Carlos Jarque Sergio Chiva Mariano Martin Newcastle Innovation Centre Procter&Gamble R&DNewcastle upon TyneUK departamento de Ingenieria Quimica y Textil.universidad de salamanca SalamancaSpain departamento de Ingenieria Mecanica y Construccion Universitat Jaume ICastellon de la PlanaSpain Instituto de Tecnologia Ceramica Universitat Jaume ICastellon de la PlanaSpain

This study evaluates the single droplet drying(SDD)of *** data are used to validate a theoretical multistage *** experiments are carried out in an acoustic levitator analysing six different detergent formulations at 393 *** work is completed by developing a model based on conservation *** model is composed of the three stages observed in the drying *** the first stage,an external surface drying stage occurs until the surface is saturated and the crust is *** the next stage,the drying rate is governed by diffusion through the *** the same time,the particle heats up until boiling conditions are achieved in the core of the *** this point,the third stage *** the final stage,the droplet core is in boiling conditions which are governed by the pressure drop through the crust and the concentration of *** model has been evaluated for the different formulations being flexible to predict the drying of different mixtures with good accuracy.

关键词： Drying Single droplet Acoustic levitator detergents

Semileptonic bc to cc and bb to bc baryon decays and heavy quark spin symmetry

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Chinese Physics C 2010年第9期34卷 1364-1367页

作者： J.Nieves J.M.Flynn E.Hernández Instituto de Física corpuscular (IFIC) Centro Mixto Universidad de Valencia-CSICInstitutos de Investigación de Paterna School of Physics and Astronomy University of Southampton departamento de Física Fundamental e IUFFyM Universidad de Salamanca

We study the semileptonic decays of the lowest-lying bc baryons to the lowest-lying cc baryons （Ξ （＊） bc → Ξ （＊） cc and Ω （＊） bc → Ω （＊） cc ）,in the limit m b,m c Λ QCD and close to the zero recoil *** separate heavy quark spin symmetries make it possible to describe all these decays using a single form *** also show how these constraints can be used to test the validity of different quark model *** to bc baryon decays are also discussed.

关键词： heavy quark spin symmetry semileptonic decays constituent quark modelsIf