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Twists and Gromov Hyperbolicity of Riemann Surfaces

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Acta Mathematica Sinica,English Series 2011年第1期27卷 29-44页

作者： Katsuhiko MATSUZAKI jose M. RODRIGUEZ Department of Mathematics School of Education Waseda University Shinjuku Tokyo 169-8050 Japan Departamento de Matemdticas Universidad Carlos IH de Madrid Avenida de la Universidad 30 28911 Legangs Madrid Spain

The main aim of this paper is to study whether the Gromov hyperbolicity is preserved under some transformations on Riemann surfaces （with their Poincare metrics）. We prove that quasiconformal maps between Riemann surfaces preserve hyperbolicity; however, we also show that arbitrary twists along simple closed geodesics do not preserve it, in general.

关键词： Quasiconformal maps Riemann surfaces Gromov hyperbolicity

Female mate choice based on pheromone content may inhibit reproductive isolation between distinct populations of Iberian wall lizards

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Current Zoology 2013年第2期59卷 210-220页

作者： Marianne GABIROT Pilar LOPEZ jose MARTIn Departement Ecologie Comportementale (U.M.R. 5175) CEFE-CNRS 1919 Route de Mende F34293 Montpellier Cedex 5 France Departamento de Ecologia Evolutiva Museo Naeional de Ciencias Naturales C.S.I.C. Jos6 Guti6rrez Abascal 2 28006 Madrid Spain

The Iberian wall lizard Podarcis hispanica forms part of a species complex with several morphologically and geneti- cally distinct types and populations, which may or may not be reproductively isolated. We analyzed whether female mate choice based on males＇ chemical signals may contribute to a current pre-mating reproductive isolation between two distinct populations of P. hispanica from central Spain. We experimentally examined whether females choose to establish territories on areas scent-marked by males of their own population, versus areas marked by males of the other population. Results showed that fe- males did not prefer scent-marks of males from their own population. In contrast, females seemed to attend mostly to among-individual variation in males＇ pheromones that did not differ between populations. Finally, to test for strong premating re- productive isolation, we staged intersexual encounters between males and females. The population of origin of males and females did not affect the probability nor the duration of copulations. We suggest that the different environmental conditions in each population might be selecting for different morphologies and different chemical signals of males that maximize efficiency of communication in each environment. However, females in both populations based mate choice on a similar condition-dependent signal of males. Thus, male signals and female mate choice criteria could be precluding premating reproductive isolation between these phenotypically ＂distinct＂ populations [Current Zoology 59 （2）： 210-220, 2013].

关键词： Podarcis hispanica Chemical communication Mate preferences Mate recognition Species recognition Conflict

Tribological performance of tributylmethylammonium bis(trifluoromethylsulfonyl)amide as neat lubricant and as an additive in a polar oil

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Friction 2019年第3期7卷 282-288页

作者： Rubén GOnZáLEZ Diego RAMOS David BLAnCO Alfonso FERnánDEZ-GOnZáLEZ jose L.VIESCA Mark HADFIELD Antolin HERnánDEZ BATTEZ Department of Marine Science and Technology University of OviedoAsturias 33203Spain Department of Construction and Manufacturing Engineering University of OviedoAsturias 33203Spain Department of Physical and Analytical Chemistry University of OviedoAsturias 33006Spain Department of Design and Engineering Bournemouth UniversityPoole BH12 5BBUK

The ionic liquid(IL) tributylmethylammonium bis(trifluoromethylsulfonyl)amide([n4441][nTf2]) was used as neat lubricant and as an additive(1.5 wt%) in a polar oil to study its friction and wear reducing *** tests were completed for 90 minutes at room temperature and 100 °C in a reciprocating configuration at loads of 30 and 70 n,10 Hz-frequency,and 4 mm stroke *** volume was measured by confocal microscopy and the surface-IL interaction determined by *** main findings were that neat IL showed the best tribological behavior;the IL-containing mixture behaved similar to the base oil regarding friction,however outperformed the antiwear behavior of the base oil under higher temperature;surface-IL chemical interaction was found mainly at 100 °C.

关键词： ionic liquid additive friction wear polar oil

THE InTEGRATIOn OF STIFF SYSTEMS OF ODEs USInG nDFs AnD MEBDFs

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Journal of Computational Mathematics 2013年第2期31卷 175-189页

作者： Elisabete Alberdi Celaya Juan jose Anza Department of Applied Mathematics EUIT de Minas y Obras P(tblicas Universidad del Pals Vasco UPV/EHU Colina de Beurko s/n 48902 Barakaldo Spain Department of Applied Mathematics ETS de Ingenieria de Bilbao Universidad del Pals Vasco UPV/EHU Alameda de Urquijo s/n 48013 Bilbao Spain

In this paper we modify the MEBDF method using the nDFs as predictors instead of the BDFs. We have done it in three different ways： changing both predictors of the MEBDF, changing only the first predictor and changing only the second one. We have called the new methods MEnDF, MEnBDF and MEBnDF respectively. The new methods are A-stable up to order 4 and the stability properties of the new methods are better than the MEBDF method.

关键词： BDF nDF MEBDF Stiff ODEs Stability.

Contrasting size-dependent life history strategies of an insular lizard

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Current Zoology 2020年第6期66卷 625-633页

作者： Andreu Rotger jose Manuel Igual Giacomo Tavecchia Animal Demography and Ecology Unit GEDAIMEDEA(CSIC-UIB)c M.Marques 2101790EsporlesSpain

In many species with continuous growth,body size is an important driver of life-history tactics and its relative importance is thought to reflect the spatio-temporal variability of selective *** developed a deterministic size-dependent integral projection model for 3 insular neighboring lizard populations with contrasting adult body sizes to investigate how size-related selective pressures can influence lizard life-history *** each population,we broke down differences in population growth rates into contributions from size-dependent body growth,survival,and feeundity.A life table response experiment(LTRE)was used to compare the population dynamics of the 3 populations and quantify the contributions of intrinsic demographic coefficients of each population to the population growth rate(z).Perturbation analyses revealed that the largest adults contributed the most to the population growth rate,but this was not true in the population with the smallest adults and size-independent *** we were not able to identify a single factor responsible for this difference,the combination of the demographic model on a continuous trait coupled with an LTRE analysis revealed how individuals from sister populations of the same species follow different life strategies and showed different compensatory mechanisms among survival,individual body growth,and *** results indicate that body size can play a contrasting role even in closely-related and closely-spaced populations.

关键词： body size capture-recapture integral projection model Lilfords lizard size-dependent mortality

A new Phasor Estimator for PMU Applications:P Class and M Class

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Journal of Modern Power Systems and Clean Energy 2020年第1期8卷 55-66页

作者： jose R.Razo-Hernandez Arturo Mejia-Barron David Granados-Lieberman Martin Valtierra-Rodriguez jose F.Gomez-Aguilar EnAP-Research Group Facultad de IngenieríaUniversidad Autónoma de Querétaro(UAQ)San CayetanoC.P.76807México EnAP-Research Group Departamento de Ingeniería ElectromecánicaInstituto Tecnológico Superior de Irapuato(ITESI)Colonia El CopalC.P.36821México COnACyT-Centro nacional de Investigación y Desarrollo Tecnológico(CEnIDET) Tecnológico Nacional de MéxicoInterior Internado Palmira S/NCol.PalmiraC.P.62490México

Phasor measurement units(PMUs)are fundamental tools in the applications of modern power systems,where synchronized phasor estimations are *** accuracy and dynamic performance requirements for phasor,frequency,and rate of change of frequency(ROCOF)estimations are established in the IEEE Std.C37.118.1-2011 along with the IEEE Std.C37.118.1 a-2014,where two PMU performances are suggested:P class filters for applications requiring fast response and M class filters for applications requiring high rejection to aliased *** this paper,a methodology to design new phasor estimators that satisfy the P class and M class requirements in PMUs is *** proposed methodology is based on finite impulse response filters,brick-wall filters,and complex filter design concepts,where frequency range,time performance,harmonic rejection and out-of-band interference requirements are considered in its design.A comparative analysis using the reference model given by the IEEE Std.C37.118.1 is *** results show the effectiveness of the phasor estimators under steady-state and dynamic conditions according to the PMU standard,making them suitable tools for applications in power systems.

关键词： Brick-wall filter complex filter IEEE Std.C37.118.1 M class P class phasor measurement unit(PMU) phasor estimator

Optimal Multimodel Representation by Laguerre Filters Applied to a Communicating Two Tank System

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Journal of Systems Science & Complexity 2018年第3期31卷 621-646页

作者： SAMEH Adaily ABDELKADER Mbarek TAREK Garna jose Ragot Laboratory of Automatic Control Signal and Image Processing National Engineering School of Monastir University of Monastir 5019 Tunisia Higher Institute of Applied Science and Technology of Sousse University of Sousse 4003 Tunisia Center of Research on Automatic of nancy CNRS 2 Avenue de la for de Haye 54516 Vandoeuvre Cedex France.

This paper presents the development of a new nonlinear representation by exploiting the multimodel approach and the new linear representation ARX-Laguerre for each operating region. The resulting multimodel, entitled ARX-Laguerre multimodel, is characterized by the parameter number reduction with a recursive representation. However, a significant reduction of this multimodel is subject to an optimal choice of Laguerre poles characterizing each local linear model ARX-Laguerre. Therefore, the authors propose an optimization algorithm to estimate, from input/output measurements, the optimal values of Laguerre poles. The ARX-Laguerre multimodel as well as the proposed optimization algorithm are tested on a continuous stirred tank reactor system （CSTR）. Moreover, the authors take into account a practical validation on an experimental communicating two tank system （CTTS）.

关键词： ARX-Laguerre model Laguerre poles multimodel approach optimization

An overview on nucleation theories and models

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Journal of Rare Earths 2019年第10期37卷 1015-1022页

作者： Marcos Flavio de Campos jose Adilson de Castro Department of Mechanical Engineering Federal Fluminense University

Several different models for coercivity are discussed. There are two main situations: i) nanocrystalline magnets, with grain size bellow the single domain particle size, and ii) magnets with grain size above single domain particle size. The described theories and models are general, and can be applied in either ndFeB magnets, SmFeCoCuZr or strontium ferrite magnets. The spring effect observed in isotropic nanocrystalline magnets can be explained with the Stoner-Wohlfarth model. Modifications of the StonerWohlfarth model are necessary to take into account the effect of interaction between grains. When the grain size is above the single domain size, energy considerations show that nucleation should occur at the surface of grains. nucleation is interpreted as a two-step process, where domain wall displacement occurs for grain size above single domain size, after a nucleus is first formed. The effect of grain size on the coercive field is discussed.

关键词： Coercivity nucleation Grain size Spring effect nd-Fe-B Permanent magnet

5Ws of Green and Sustainable Software

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Tsinghua Science and Technology 2020年第3期25卷 401-414页

作者： Coral Calero Javier Mancebo Felix Garcia Maria Angeles Moraga jose Alberto Garcia Berna jose Luis Fernandez-Aleman Ambrosio Toval the Institute of Technology and Information Systems University of Castilla-La ManchaCiudad Real 13071Spain. the Department of Informatics and Systems University of MurciaMurcia 30003Spain

Green and Sustainable Software has emerged as a new and highly active area in the software *** several years of research and work,we believe that it is now necessary to obtain a general snapshot of how the research in this area is *** do so,we have applied the 5 Ws(why,when,who,where,and what),a formula for getting the complete story on a *** have therefore carried out a study,using 542 publications related to Green and Sustainable Software research;these were recovered using *** results obtained allow us to conclude that it is important to identify key elements of the research to allow researchers be fully aware of the state of the research on Green and Sustainable Software(why);the study uses papers published between 2000 and the beginning of november 2018(when);the most prolific authors are mainly from Europe,although the USA is the most active country,Green and Sustainable Software being a very interactive area with a good number of multinational publications(who);the top five keywords related to sustainable aspects are Green Software,Green IT,Software Sustainability,Energy Consumption,and Energy Efficiency(what);finally,as regards the places authors prefer to publish in,there is almost a complete balance between conferences and journals,with a trend towards an increase in the number of publications(where).

关键词： Green Software Sustainable Software Software Engineering Software Sustainability Energy Efficiency Energy Utilization