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Highly electroactive N–Fe hydrothermal carbons and carbon nanotubes for the oxygen reduction reaction

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Journal of Energy Chemistry 2020年第11期29卷 260-270页

作者： r.G.morais N.rey-raap J.L.Figueiredo m.F.r.pereira Associate Laboratory LSrE-LCm Departamento de Engenharia QuimicaFaculdade de EngenhariaUniversidade do PortoR.Dr.Roberto Frias s/n4200-465PortoPortugal

Glucose-derived carbons were prepared by hydrothermal carbonization of glucose followed by carbonization or activation to obtain carbon materials with different microporosities. These microporous carbons and carbon nanotubes(CNTs) were functionalized with melamine and/or iron(Ⅱ) phthalocyanine(FePc)following three different methodologies:(i) Functionalization with melamine via thermal treatment,(ii)incorporation of the lowest amount of FePc reported in the literature via incipient wetness impregnation followed by thermal treatment and(iii) functionalization with melamine followed by Fe Pc *** chemical and textural characterization of the prepared materials and their electrochemical assessment allowed to understand the role of microporosity in the incorporation of FePc and its effect on the oxygen reduction reaction(Orr). It was observed that FePc was preferentially incorporated inside the porous structure, especially in samples with more developed microporosity. However, functionalization with melamine modified the textural properties and the surface chemistry, favoring the incorporation of FePc on the surface. regarding the electrochemical performance, the presence of FePc greatly enhanced the electroactivity of the microporous catalysts. An onset potential of 0.88 V and a four-electron pathway were obtained for glucose-derived carbons, whereas the limiting current densities and kinetic current densities rose by 126% and 222%, respectively, in comparison to the base sample. Notwithstanding, the highest electrochemical activity was observed for the sample prepared with CNTs, due to the synergy between the active metal centers and their highly graphitic carbon structure. The electrochemical parameters of CNTFeP csurpass the commercial Pt/C. The half-wave potential is 40 mV higher, the limiting current density increases by 17%, and a negligible production of by-products(rved.

关键词： Iron(Ⅱ)phthalocyanine Hydrothermal carbons Carbon nanotubes Oxygen reduction reaction Electrocatalysis

Experimental and numerical characterization of 3D‑printed scaffolds under monotonic compression with the aid of micro‑CT volume reconstruction

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Bio-Design and manufacturing 2021年第2期4卷 222-242页

作者： r.Baptista m.F.C.pereira A.maurício D.rechena V.Infante m.Guedes CDP2T Departamento de Engenharia MecanicaEscola Superior de Tecnologia de SetúbalInstituto Politécnico de Setúbal2910‑761 SetúbalPortugal CErENA DECivilInstituto Superior TécnicoUniversidade de LisboaAv.Rovisco Pais11049‑001 LisbonPortugal IDmEC Instituto Superior TécnicoUniversidade de LisboaAv.Rovisco Pais11049‑001 LisbonPortugal IPFN Instituto Superior TécnicoUniversidade de Lisboa1049‑001 LisbonPortugal CeFEmA Instituto Superior TécnicoUniversidade de LisboaAv.Rovisco Pais11049‑001 LisbonPortugal

Even when damaged by injury or disease bone tissue has the remarkable ability to *** this process is limited by large size bone defects,tissue engineering is responsible for restoring,maintaining or improving tissue *** are support structures,designed to be implanted in the damaged site,supporting mechanical loads and protecting the regenerating bone *** this paper,3D-printed PLA scaffolds with three different porosity values and two different geometries were experimentally and numerically ***-CT analysis showed that fused filament fabrication can be used to produce scaffolds with the desired porosity and 100%of interconnected *** monotonical compression,scaffolds apparent compressive modulus increased from 89 to 918 mPa,while yield stress increased from 2.9 to 27.5 mPa as porosity decreased from 70 to 30%.Open porosity decreased up to 8%on aligned scaffolds and 14%on staggered scaffolds,after compression,while scaffold’s surface-to-volume ratio highest reduction(7.48 to 4.55 mm−1)was obtained with aligned low porosity ***-CT volume reconstruction allowed for scaffold simplified numerical models to be built and *** agreement was found when predicting scaffold’s apparent compressive ***,it can be concluded that 3D printing is a viable scaffold manufacturing technique for trabecular bone replacement.

关键词： Scaffold Pore design mechanical behavior micro-CT analysis Finite element method

Inter-Individual rapid Force Improvements after mixed Session and Traditional Periodization in Aging Adults:A randomized Trial

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Journal of Science in Sport and Exercise 2021年第2期3卷 125-137页

作者： Bruno monteiro moura Ewertton de Souza Bezerra Lucas B.r.Orssatto Antonio renato pereira moro fernando Diefenthaeler Universidade Federal de Santa Catarina Centro de DesportosLaboratório de BiomecânicaFlorianópolisCEP 88040-900Brazil Universidade Federal do Amazonas Faculdade de Educação Física e FisioterapiaLaboratório de Estudo do Desempenho HumanoManausCEP 38400-678Brazil School of Exercise and Nutrition Sciences Queensland University of TechnologyBrisbane 4059Australia

Background Different periodization models have been widely used to improve maximum and rapid force in aging ***,it is unclear if some specific model can influence the remarkable heterogeneity of responsiveness to rapid torque improvements following resistance *** Compare the effects of mixed session periodization(mSP)and traditional(TP)models on neuromuscular performance and individual responsiveness in aging *** Twenty-two aging men and women(64.6±5.2 years old;1.68±0.1 m;77.8±16.0 kg)completed the intervention *** were assigned into mSP(n=11)or TP(n=11)resistance training for lower *** outcome measures normalized dynamic leg press(5-rm:Bm),absolute and normalized knee isometric peak torque(PT and PT:Bm)and rate of torque development,and impulse were assessed at baseline and after three blocks of a 9-wk resistance training(3 sessions per week).Thigh leg lean mass was assessed by dual-energy x-ray absorptiometry at baseline and after the *** Similar increases were observed for 5-rm:Bm(mSP:28.8%±13.5%and TP:26.4%±7.6%,PmSP:223.7±50.7 N·m and TP:189.9±58.6 N·m,Prved for PT:Bm(mSP:16.4%±16.5%and TP:4.7%±9.2%,P>0.05).Absolute and normalized rTD remained unchanged throughout intervention(P>0.05),but both groups improved impulse(mSP:22.1%±25.7%and TP:12.6%±45.2%,PmSP responders(n=5)presented significant time effect for absolute rTD(Pmpulse(Priodization protocols increased 5-rm:Bm and PT,it was not interchangeable through improve-ments in rTD even adopting power training ***,these results suggest a great inter-individual variability following different periodization models for aging people.

关键词： rate of torque development Impulse Strength training muscular strength Hypertrophy Periodization

Cr（V）involvementin the toxicity pathway of testicular damage

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Asian Journal of Andrology 2002年第2期4卷 153-155页

作者： m.L.pereira T.m.Santos 等 DepartmentofBiology Departmentofchemistry UniversityofAveriro3810－193AveiroPortugal

Aim: The functional integrity of the blood-testis barrier (BTB) in male mice exposed to Cr(V) was studied in order to clarify the mechanism underlying testicular injury. methods: Adult male mice were subcutaneously injected repeated doses of 8.02 mmol (0.5 mL) of Cr/*** for 5 days. Animals receiving a similar volume of bis(hydroxyethyl)-aminotris(hydroxymethyl)methane buffer (BT) were used as controls. The animals were sacrificed on day 6 and small fragments of seminiferous tubules, approximately 8-10 mm length, were incised and sutured at both ends. They were exposed in vitro to horseradish peroxidase-containing culture medium for 10 minutes. Tissues were then fixed and processed for ultrastructural studies. results: Controls and Cr(V)-treated group resulted in the uptake of the tracer by Sertoli cells. However, the major finding consisted in the permeability of the BTB only in the Cr(V)-group, as evidenced by the presence of the tracer within the junctions between the neighbouring Sertoli cells. Conclusion: The BTB is disrupted in mice submitted to Cr(V). The permeability of the BTB is a crucial feature to be investigated for the understanding of lesions within the seminiferous tubule.

关键词： Blood-testis barrier Cr(V) Horseradish peroxidase Integrity Spermatogenesis

作物根区底部土壤水分向上运移通量的计算方法

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水利学报 2001年第12期32卷 19-25页

作者：刘钰蔡林根 r.m.fernando L.S.pereira 中国水利水电科学研究院水利所北京100044 葡萄牙里斯本技术大学农学院农业工程系

本文用河北雄县试验站的实测资料验证了一维土壤水动力学模型—WAVE模型 (WaterandAgrochemicalsintheSoilandVadoseEnvironment) ,率定了土壤水力学特性参数和作物根系吸水函数 .在此基础上 ,应用该模型模拟不同地下水埋深和不同作物... 详细信息

本文用河北雄县试验站的实测资料验证了一维土壤水动力学模型—WAVE模型 (WaterandAgrochemicalsintheSoilandVadoseEnvironment) ,率定了土壤水力学特性参数和作物根系吸水函数 .在此基础上 ,应用该模型模拟不同地下水埋深和不同作物腾发量条件下根区底部向上水分通量的变化 ,从而得到地下水对根层的补给量与根层土壤储水量的关系 .把这一关系用于制定和评价灌溉制度的水量平衡模型当中。

关键词：地下水毛管上升通量计算方法水量平衡作物根区底部水分通量试验材料 WAVE模型动态模拟土壤水动力学模型

Solar spectral conversion based on plastic films of lanthanide-doped ionosilicas for photovoltaics:Down-shifting layers and luminescent solar concentrators

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Journal of rare Earths 2020年第5期38卷 531-538页

作者： m.A.Cardoso S.F.H.Correia A.r.Frias H.m.r.Goncalves r.F.P.pereira S.C.Nunes m.Armand P.S.André V.de Zea Bermudez r.A.S.Ferreira Department of Physics and CICECO-Aveiro Institute of materials University of Aveiro3810-193AveiroPortugal Department of Chemistry and CQ-Vr University of Tras-os-Montes e Alto Douro5000-801Vila RealPortugal Instituto de Telecomunicacoes University of Aveiro3810-193AveiroPortugal rEQUImTE Instituto Superior de Engenharia do Porto4200-072PortoPortugal Chemistry Centre and Chemistry Department University of Minho4710-057BragaPortugal CICS-Health Sciences research Center and Chemistry Department University of Beira Interior6201-001CovilhaPortugal Electrical Energy Storage Department CIC EnergiguneParque Tecnologico de AlavaMinano01510Spain Department of Electrical and Computer Engineering Instituto de TelecomunicacoesInstituto Superior TecnicoUniversidade de Lisboa1049-001LisbonPortugal

The mismatch between the photovoltaic(PV)cells absorption and the solar irradiance on earth is one of the major limitations towards more efficient PV energy *** aspect was addressed by downshifting the solar irradiance on Earth through luminescent down-shifting layers based on lanthanidedoped surface-functionalized ionosilicas(ISs)embedded in poly(methyl methacrylate)(PmmA)coated on the surface of commercial Si-based PV *** IS-PmmA hybrid materials exhibit efficient solar radiation harvesting(spectral overlap of^9.5×10^19 photons/(s·m2))and conversion(quantum yield^52%).The direct solar radiation and the down-shifted radiation are partially guided and lost through total internal reflection to the layer edges being unavailable for PV conversion of the coated PV *** tuning the down-shifting layer thickness,it also acts as luminescent solar concentrator enabling the collection of the guided radiation by flexible PV cells applied on the borders of the down-shifting layer leading to an enhancement of the PV energy conversion from^5%(in the case of the single-use of the luminescent down-shifting layer)to^13%comparing with the bare PV *** overall electrical output of the device resulted in an absolute external quantum efficiency increase of^32%for the optimized Eu^3+-based films in the UV spectral region(compared with the bare PV device,which is among the best values reported so far).

关键词： Ionosilicas Lanthanides Photovoltaics Luminescent solar concentrators Down-shifting layers Silicon photovoltaic cells

mechanical characterization of sisal reinforced cement mortar

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Theoretical & Applied mechanics Letters 2014年第6期4卷 26-30页

作者： r.Fujiyama F.Darwish m.V.pereira Department of mechanical Engineering Para Federal University Department of Civil Engineering Fluminense Federal University Department of materials Engineering Catholic University of rio de Janeiro

This work aims at evaluating the mechanical behavior of sisal fiber reinforced cement mortar. The composite material was produced from a mixture of sand, cement, and water. Sisal fibers were added to the mixture in different lengths. mechanical characterization of both the composite and the plain mortar was carried out using three point bend, compression, and impact tests. Specimens containing notches of different root radii were loaded in three point bending in an effort to determine the effect of the fibers on the fracture toughness of the material. The results obtained indicate that, while fiber reinforcement leads to a decrease in compressive strength, J-integral calculations at maximum load for the different notch root radii have indicated, particularly for the case of long fibers, a significant superiority of the reinforced material in comparison with the plain cement mortar, in consistence with the impact test data.

关键词： composite material impact energy fracture initiation J-integral

The inception of a Paleotethyan magmatic arc in Iberia

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Geoscience Frontiers 2015年第2期6卷 297-306页

作者： m.F.pereira A.Castro C.Fernández IDL Departamento de Geociências ECT Universidade de évora Departamento de Geología Universidad de Huelva Departamento de Geodinámica y Paleontología Universidad de Huelva

This paper presents a compilation of recent U-Pb （zircon） ages of late Carboniferous-early Permian （LC EP） calc-alkaline batholiths from lberia, together with a petrogenetic interpretation of magma generation based on comparisons with mesozoic and Tertiary Cordilleran batholiths and experimental melts. Zircon U-Pb ages distributed over the range ca. 315-280 ma, indicate a linkage between calc-alkaline magmatism, Iberian orocline generation and Paleotethys subduction. It is also shown that Iberian LC-EP calcalkaline batholiths present unequivocal subduction-related features comparable with typical Cordilleran batholiths of the Pacific Americas active margin, although geochemical features were partially obscured by local modifications of magmas at the level of emplacement by country rock assimilation. When and how LC-EP calc-alkaline batholiths formed in Iberia is then discussed, and a new and somewhat controversial interpretation for their sources and tectonic setting （plume-assisted relamination） is suggested. The batholiths are proposed to have formed during the subduction of the Paleotethys oceanic plate （Pangaea self-subduction） and, consequently, they are unrelated to Variscan collision. The origin of the Iberian batholiths is related to the Eurasian active margin and probably represents the inception of a Paleotethvan arc in the core of Pangaea.

关键词： Permo-Carboniferous Calc-alkaline arc-related batholiths Pangaea Paleotethys subduction Variscan and Cimmerian cycles

Carbon monoxide as C1 Building Block in Fine Chemical Synthesis

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Chinese Journal of Chemistry 2024年第2期42卷 199-221页

作者： rui m.B.Carrilho mario J.F.Calvete Gabor mikle Laszlo Kollar mariette m.pereira University of Coimbra Coimbra Chemistry CentreDepartment of ChemistryRua Larga3004-535 CoimbraPortugal Department of General and Inorganic Chemistry and ELKH-PTE research Groupfor Selective Chemical Syntheses University of PecsIfjusag utja 6H-7624 PecsHungary

Carbon monoxide(CO)has become one of the most relevant and versatile renewable C1 building blocks for chemical synthesis,especially in the fine chemicals industry,due to the development of efficient and selective catalysts for its *** this review,we present a comprehensive critical analysis of the last 10 years literature on the use of CO as a renewable feedstock for fine chemicals *** review is organized by type of catalytic reaction,namely alkene and alkyne carbonylation,hydroformylation,carbonylation of aryl halides,carbonylative cross-coupling and C-H *** examples of the synthesis of relevant building blocks and/or known pharmaceuticals are *** is placed on examples of utilizing CO as the C1 building block in one or more catalytic *** catalyst used and the reaction conditions are consistently presented throughout all of the examples.

关键词： Carbon monoxide Fine chemicals Carbonylation Hydroformylation C-H functionalization