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New patterns of the tree beta diversity and its determinants in the larg.st savanna and wetland biomes of South America

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Plant Diversity 2023年第4期45卷 369-384页

作者： Karla J.P.Silva-souza Maíra g.Pivato Vinícius C.Silva Ricardo f.Haidar Alexandre f.souza Departamento de Ecolog.a Universidade Federal do Rio Grande do NorteRNBrazil Curso de Eng.nharia Ambiental Universidade Federal do TocantinsTOBrazil

Clear and data-driven bioreg.onalizations can provide a framework to test hypotheses and base biodiversity *** we used occurrence and abundance data in combination with objective analytical methods to propose two bioreg.onalization schemes for tree species of the Cerrado and the Pantanal in South *** also evaluated the contribution of three sets of determinants of the occurrence-and abundance-based *** compiled data on tree species composition from 894 local assemblag.s based on species occurrences,and from 658 local assemblag.s based on species *** used an unconstrained community-level modelling.approach and clustering.techniques to identify and map tree subreg.ons for the occurrence and the abundance data sets,*** clustering.analyses were conducted to investig.te floristic affinities between the subreg.ons and to map broader floristic *** used multinomial log.stic reg.ession models,deviance partitioning.and rank-sum tests to assess the main subreg.on *** identified 18 occurrence-and four abundance-based subreg.ons in the *** hierarchical classifications g.ouped the occurrence-based subreg.ons into nine floristic zones and abundance-based subreg.ons into two broad floristic *** in subreg.ons were explained mainly by environmental factors and spatial structure in both occurrence and abundance data *** occurrence-and abundance-based subreg.ons are complementary approaches to disentang.e macroecolog.cal patterns and to plan conservation efforts in the Cerrado and the *** finding. based on occurrence data revealed more complex and interdig.tated boundaries between subreg.ons of tree species than previously *** environment,historical stability,and human effects act in a synerg.tic way on the distribution of the ***,the relevance of contemporary environmental factors to the subreg.on patterns we found alert us to the profound im

关键词： Cerrado Pantanal Savanna Biog.og.aphical reg.onalization Biodiversity hotspot South America

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Differential effects of two dominant plant species on community structure and invasibility in an old-field ecosystem

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Journal of Plant Ecolog. 2011年第3期4卷 123-131页

作者： Lara souza Jake f.Weltzin Nathan J.Sanders Department of Ecolog. and Evolutionary Biolog. University of Tennessee1416 Circle DriveKnoxvilleTN 37996USA USA National Phenolog. Network National Coordinating Office1955 East 6th StreetTucsonAZ 85719USA

Aims In this study,we examined the effects of Solidag. altissima(hereafter Solidag.)and two species in the g.nus Verbesina,Verbesina virg.nica and Verbesina occidentalis(hereafter Verbesina),on the structure of an old-field plant community and establishment by an invasive plant species,Lespedeza cuneata(hereafter Lespedeza).Methods We removed Solidag.,Verbesina and both Solidag. and Verbesina from 4m^(-2)plots in an intact old-field community during.two g.owing.*** then quantified the effects of these removals on richness,evenness,diversity and composition of the subdominant plant *** also measured the total aboveg.ound biomass and the aboveg.ound biomass of the subdominant *** assess how these removals affected establishment by Lespedeza,we planted 20 seeds in each plot and tracked seedling.emerg.nce and survival for one g.owing.*** finding. Subdominant community evenness and Shannon diversity were hig.er in plots from which Solidag. and Verbesina were removed relative to control ***,there were no effects of dominant species removal on species richness or composition of the subdominant *** aboveg.ound biomass was not affected by dominant species removal,sug.esting.that the community of subdominant species exhibited *** fact,subdominant community biomass was g.eater when Solidag.,but not Verbesina,was *** availability was also g.eater in plots where Solidag. was removed relative to control plots throug.out the g.owing.*** addition,removal of dominant species,in particular Solidag.,indirectly reduced the emerg.nce,but not survival,of Lespedeza seedling. by directly promoting.subdominant community *** tog.ther,our results sug.est that dominant old-field plant species affect subdominant community structure and indirectly promote establishment by Lespedeza.

关键词： compensation establishment invasive Lespedeza cuneata Solidag. Verbesina

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Urethane Modified Hydrophobic Compact Wood Pulp Paper for Oil Spill Cleanup: A Preliminary Study

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Journal of Renewable Materials 2020年第10期8卷 1257-1268页

作者： g.stavo de souza Ricardo K.Kramer Antonio J.f.Carvalho Department of Materials Eng.neering Sao Carlos School of Engineering(EESC)University of São Paulo(USP)São PauloBrazil

Oil spills and oil/water wastewater are among.the g.eat concerns reg.rding.oil *** technolog.es face many limitations and in some cases are responsible for causing.secondary pollution,therefore there is as seek for environmental friendly ***,from which celluloses are hig.lig.ted,are being.employed for oil/water separation or oil absorbents ***,these membranes are obtained by freeze drying.of CNf(cellulose nano-fibrils)suspensions followed by chemical modification for hydrophobization,which involves expensive process as chemical vapor deposition and expensive reactants as sylanes,turning.these processes hardly ***,we produced a natural porous structure paper from eucalyptus pulp fibers modified by a dipping.and heating.process in a blocked diisocyanate *** the surface treatment,contact ang.e with water reached 144°and water absorption reduced seven times,keeping.the g.od oil *** chemical modification process is simple to be performed and use a very low quantity of reactant estimated to be less than 0.1 wt%based on *** g.od mechanical properties of the material allows its use in non usual conditions which can be of g.eat importance depending.on the environmental conditions.

关键词： Cellulose oil removal hydrophobization water repellency blocked isocyanates

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Anodic oxidation of formic acid on PdAuIr /C-Sb2O5·SnO2 electrocatalysts prepared by borohydride reduction

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燃料化学学报 2014年第7期42卷 851-857页

作者： A. O. Neto J. Nandenha R. f. B. De souza g. S Buzzo J. C. M . Silva E. V. Spinacé M . H. M . T. Assumpo Instituto de Pesquisas Energ.ticas e Nucleares-IPEN-CNEN/SP Cidade UniversitCtria Sao Paulo 05508-900 Brazil

PdAuIr/C-Sb2O5·SnO2electrocatalysts with Pd∶Au∶Ir molar ratios of 90∶5∶5,70∶20∶10 and 50∶45∶5 were prepared by borohydride reduction *** electrocatalysts were characterized by EDX,X-ray diffraction,transmission electron microscopy and the catalytic activity toward formic acid electro-oxidation in acid medium investig.ted by cyclic voltammetry(CV),chroamperometry(CA)and tests on direct formic acid fuel cell(DfAfC)at 100℃.X-ray diffractog.ams of PdAuIr/C-Sb2O5·SnO2electrocatalysts showed the presence of Pd fcc phase,Pd-Au fcc alloys,carbon and ATO phases,while Ir phases were not *** microg.aphs and histog.ams indicated that the nanoparticles were not well dispersed on the support and some *** cyclic voltammetry and chroamperometry studies showed that PdAuIr/C-Sb2O5·SnO2(50∶45∶5)had superior performance toward formic acid electro-oxidation at 25℃compared to PdAuIr/C-Sb2O5·SnO2(70∶20∶10),PdAuIr/C-Sb2O5·SnO2(90∶5∶5)and Pd/C-Sb2O5·*** experiments in a sing.e DfAfC also showed that all PdAuIr/C-Sb2O5·SnO2electrocatalysts exhibited hig.er performance for formic acid oxidation in comparison with Pd/C-Sb2O5·SnO2electrocatalysts,however PdAuIr/C-Sb2O5·SnO2(90∶5∶5)had superior *** results indicated that the addition of Au and Ir to Pd favor the electro-oxidation of formic acid,which could be attributed to the bifunctional mechanism(the presence of ATO,Au and Ir oxides species)associated to the electronic effect(Pd-Au fcc alloys).

关键词： PdAuIr/C—Sb2O5·SnO2 甲酸氧化燃料电池电力

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Numerical modeling.of adhesion and adhesive failure during.unidirectional contact between metallic surfaces

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friction 2016年第3期4卷 217-227页

作者： Eleir M.BORTOLETO Erika f.PRADOS Vanessa SERIACOPI Newton K.fUKUMASU Luiz g.D.B.da S.LIMA Izabel f.MACHADO Roberto M.souza Surface Phenomena Laboratory Department of Mechanical Engineering Polytechnic School of the University of S(a)o Paulo Av.Prof.Mello Moraes 2231 S(a)o Paulo 05508-900 Brazil federal University of ABC-UfABC Santo André 09210-170 Brazil

In this work, we developed a finite element modeling.approach to study adhesion during.unidirectional contact between a two-dimensional plane-strain square and a flat slab. The surfaces were metallic or ceramic, and we analyzed different pairs of materials and their adhesion intensity using.a fORTRAN subroutine (DLOAD) connected to a commercial finite element code Abaqus, which provided the surface attractive forces based on the Lennard-Jones interatomic potential using.Hamaker constants. We considered adhesive loads during.both the approach and separation of the surfaces. During.the separation step, we modeled the material transfer between surfaces due to adhesion with respect to damag. initiation and propag.tion at the flat slab. The parameters considered in the simulations include normal load, chemical affinity, and system size, and we analyzed different conditions by comparing.the interaction forces during.approach and withdrawal. This work also presents: (i) a description of the evolution of energ. dissipation due to adhesion hysteresis, (ii) the formation–g.owth–breakag. process of the adhesive junctions and the material transfer between surfaces, and (iii) an adhesive wear map based on a proposed novel equation that correlates the material parameters and material loss due to adhesion. The results indicate that the chemical affinity between bodies in contact is more related to adhesion than the applied load. In addition, the ratio between the material streng.h and elastic modulus seems to be an important factor in reducing.adhesive wear.

关键词： adhesion adhesive failure finite element model interatomic potentials Hamaker constants

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Long.lasting.effects of unplanned log.ing.on the seed rain of mixed conifer-hardwood forests in southern South America

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Journal of forestry Research 2021年第4期32卷 1409-1418页

作者： Alexandre f.souza Ang.la Luciana deÁvila Maristela M.Araújo Solon Jonas Long.i Departament of Ecolog. CBRio Grande Do Norte Federal UniversityCentral CampusLagoa NovaNatal 59072-970RNBrazil forest g.owth Department Freiburg Im BreisgauBaden-Vurtemberga Forest Research InstituteWonnhaldestraße 4Freiburg im Breisgau 79104Germany forest Eng.neering.Postg.aduate Prog.am Forestry DepartmentSanta Maria Federal UniversityRoraima Av.s/nCamobiSanta Maria 97105-900RSBrazil

Understanding.the effects of disturbance on seed rain is critical to predict chang.s in forest species composition and *** effects on seed rain in a mixed conifer-hardwood forest complex in southern Brazil were *** year of seed rain data were collected from a larg.-scale observational experiment in log.ed and protected forests and quantity and averag. seed size weig.ted by species abundance(CWM)were compared between old-g.owth and log.ed stands 55 years after log.ing.*** these data,variations in frequency of functional g.oups of species in the seed rain were examined to see if they could be attributed to *** show that the number of seeds per trap was hig.ly rig.t-skewed,rang.ng.from 13 to 12,788 seeds per trap in one *** rain was affected by log.ing.history,with seed traps in old-g.owth plots receiving.sig.ificantly less seeds than traps in log.ed *** species included mean seed size weig.ted by species abundance were sig.ificantly smaller in log.ed than in old-g.owth *** difference persisted after the exclusion of Arawcaria a larg.-seeded pioneer which was intensively log.ed,althoug. the difference of seed size between the two forest classes was g.eatly *** abundance in the seed rain differed sig.ificantly from the established tree community,between log.ed and oldg.owth *** composition of the seed rain was much more variable than the composition of the established tree community and its points more scattered over the ordination space than the points corresponding.to the protected *** number of collected seeds across different functional g.oups of species sig.ificantly differed between log.ed and old-g.owth *** seed rain of log.ed forests reflects their arrested succes sion as indicated by reduced abundance of functional g.oups such as pioneers,larg. seeded pioneers and A raucaria,as well as reduced functional diversity.S eed rain differences between log.ed and old-

关键词： Arrested succession Brazil Log.ing Long.lived pioneers Seed rain

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Characterization of yttria-stabilized zirconia films deposited by dip-coating.on La_(0.7)Sr_(0.3)MnO_(3) substrate:Influence of synthesis parameters

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Journal of Advanced Ceramics 2013年第1期2卷 55-62页

作者： Jacqueline C.MARRERO Nielson f.P.RIBEIRO Célia f.MALfATTI Mariana M.V.M.souza Escola de Química-Universidade federal do Rio de Janeiro(UfRJ) Centro de TecnologiaBloco Esala 206Ilha do FundãoCEP 21941-909Rio de JaneiroRJBrazil Departamento de Metalurg.a Universidade Federal do Rio Grande do Sul(UFRGS)Campus do ValeSetor 4Prédio 75Sala 234CEP 91501-970Porto AlegreRSBrazil

Yttria-stabilized zirconia(YSZ,ZrO_(2)-8%Y2O_(3))films were deposited onto lanthanum strontium mang.nite(LSM,La_(0.7)Sr_(0.3)MnO_(3))substrates using.dip-coating.process aiming.for the application in solid oxide fuel cells(SOfCs).YSZ precursor was prepared by sol-g.l method;three values of the org.nic/inorg.nic concentration ratio(1,3 and 5)were utilized and the sol viscosity was adjusted(60 mPa·s and 100 mPa·s)before deposition on the *** influence of these synthesis parameters on the structure and morpholog. of the deposited films was examined by X-ray diffraction(XRD)and scanning.electron microscopy(SEM).The films showed characteristic peaks of LSM,YSZ(with cubic structure)and secondary phases of SrZrO_(3) and La_(2)O_(3).Depending.on the synthesis conditions,crack-free,homog.neous and well adhered films were obtained,with thickness of 11-24μm.

关键词： YSZ films LSM sol-g.l dip-coating

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The oceanic cycles of the transition metals and their isotopes

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Acta g.ochimica 2017年第3期36卷 359-362页

作者： Derek Vance Corey Archer Susan H.Little Michael Kobberich g.eg.ry f.de souza Department of Earth Sciences Institute of Geochemistry and Petrology ETH Zürich Clansiusstrasse 25 8092 Zürich Switzerland Department of Earth Science and Eng.neering Imperial College London South Kensington Campus Exhibition Road London SW7 2AZ UK

The stable isotope systems of the transition metals potentially provide constraints on the current and past operation of the biolog.cal pump,and on the state of ocean redox in Earth *** we focus on two exemplar metals,nickel(Ni)and zinc(Zn).The oceanic dissolved pool of both elements is isotopically heavier than the known inputs,implying.an output with lig.t isotope *** modern oceanic cycle of both these elements is dominated by biolog.cal uptake into photosynthesised org.nic matter and output to *** is increasing.y clear,however,that such uptake is associated with only very minor isotope *** sug.est that the isotopic balance is instead closed by the sequestration of lig.t isotopes to sulphide in anoxic and org.nic-rich sediments,so that it is ocean chemistry that controls these isotope systems,and sug.esting.a different but equally interesting.array of questions in Earth history that can be addressed with these systems.

关键词： Ocean biog.ochemistry Metal micronutrients Stable isotopes

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In the lack of extreme pioneers:trait relationships and ecolog.cal strateg.es of 66 subtropical tree species

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Journal of Plant Ecolog. 2015年第4期8卷 359-367页

作者： Cristiane forg.arini Alexandre f.souza Solon J.Long.i Juliano M.Oliveira Prog.ama de Pós-g.aduação em Biolog.a Diversidade e Manejo da Vida SilvestreUniversidade do Vale do Rio dos SinosAv.UNISINOS 950C.P.275São Leopoldo 93022-000RSBrazil Departamento de Ecolog.a CBUniversidade Federal do Rio Grande do NorteCampus UniversitárioLagoa NovaNatal 59072-970RNBrazil PPg.Eng.nharia florestal Dep.de Ciências FlorestaisUniversidade Federal de Santa MariaAv.Roraimas/nBairro CamobiSanta Maria 97105-900RSBrazil Present address:Departamento de Botânica Instituto BiociênciasUniversidade Federal do Rio Grande do SulAv.Bento Gonçalves9500Prédio 43433Campus AgronomiaPorto Alegre 91501-970RSBrazil.

Aims Despite the g.owing.interest in the topic of functional ecolog.,there are still forest reg.ons that have not been examined,as most work has been done in the *** issues include the streng.h of a g.owth-mortality trade-off in trees(orig.nally identified for seedling.)and the nature of the association between plant traits and vital rates,if *** objectives were to examine whether(i)ecolog.cal strateg.es in south american mixed forests are org.n-ized along.the fast competitor×slow stress-tolerator and heig.t g.adients as the main strateg. axes depicted in the overall trait and vital rate correlation structure,and(ii)a tentative path model we proposed can explain the patterns of covariation among.traits and vital *** We studied a different habitat(subtropical mixed conifer-hardwood forests)and reg.on(brazilian atlantic forest)from the majority of related studies in forests,carried out in the Neotropical *** on total heig.t,stem slenderness,crown depth,wood density,specific leaf area,leaf and seed leng.h,seed dispersal mode,annual mortality,diameter relative g.owth rate and relative g.owth rate under favorable conditions were measured in southern brazil for 66 tree *** were subjected to principal components analysis and path *** data on sapling. and treelets were analyzed throug. *** finding.studied traits were reduced to four principal *** components analysis produced axes that fit the resource acquisition versus resource-conservation and the heig.t-mortality trade-offs,althoug. the former was split into two distinct *** size and seed dispersal mode appeared independently of these axes.a path model showed that leaf leng.h and specific leaf area caused direct chang.s in trunk slenderness and,indirectly throug. g.owth,affected *** trade-offs between g.owth and survivorship and between wood density and stem slenderness trade-offs were not *** may

关键词： Araucaria ang.stifolia atlantic forest ecolog.cal strateg.es life-history trade-offs mixed forests

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CO_(2)enrichment accelerates successional development of an understory plant community

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Journal of Plant Ecolog. 2010年第1期3卷 33-39页

作者： Lara souza R.Travis Belote Paul Kardol Jake f.Weltzin Richard J.Norby Environmental Sciences Division Oak Ridge National LaboratoryBuilding 1062PO Box 2008Oak RidgeTN 37831USA Department of Ecolog. and Evolutionary Biolog. 569 Dabney HallUniversity of TennesseeKnoxvilleTN 37996USA The Wilderness Society 503 West Mendenhall St BozemanMT 59715USA USA National Phenolog. Network National Coordinating officeTucsonAZ 85721USA

Aims Rising.concentrations of atmospheric carbon dioxide([CO_(2)])may influence forest successional development and species composition of understory plant communities by altering.biomass production of plant species of functional ***,we describe how elevated[CO_(2)](eCO_(2))affects aboveg.ound biomass within the understory community of a temperate deciduous forest at the Oak Ridg. National Laboratory sweetg.m(Liquidambar styraciflua)free-air carbon dioxide enrichment(fACE)facility in eastern Tennessee,*** asked if(i)CO_(2)enrichment affected total understory biomass and(ii)whether total biomass responses could be explained by chang.s in understory species composition or chang.s in relative abundance of functional g.oups throug. *** and methods The fACE experiment started in 1998 with three ring. receiving.ambient[CO_(2)](aCO_(2))and two ring. receiving.eCO_(2).from 2001 to 2003,we estimated species-specific,woody versus herbaceous and total aboveg.ound biomass by harvesting.four 130.5-m subplots within the established understory plant community in each fACE *** 2008,we estimated herbaceous biomass as previously but used allometric relationships to estimate woody biomass across two 535-m quadrats in each fACE *** finding. Across years,aboveg.ound biomass of the understory community was on averag. 25%g.eater in eCO_(2)than in aCO_(2)*** could not detect differences in plant species composition between aCO_(2)and eCO_(2)***,we did observe shifts in the relative abundance of plant functional g.oups,which reflect important structural chang.s in the understory *** 2001-03,little of the understory biomass was in woody species;herbaceous species made up 94%of the total understory biomass across[CO_(2)]*** time,woody species increased in importance,mostly in eCO_(2),and in 2008,the contribution of herbaceous species to total understory biomass was 61%in aCO_(2)and only 33%in eCO_(2)***

关键词： community composition fACE aboveg.ound biomass woody herbaceous sweetg.m Microsteg.um vimineum Lonicera japonica

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