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Periodic oscillations and stability of thin variable stiffness composite laminated plates

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Periodic oscillations and stability of thin variable stiffne...

Comparison of Electron Acceleration Ability of SiO_2 and ZnS fromZnS∶Er Transient Electroluminescence

23rd International Congress of Theoretical and Applied Mechanics

作者： Pedro Ribeiro Hamed Akhavan deMec/IDMEC Faculdade de Engenharia da Universidade do PortoPortoPortugal

＜正＞Tow placement machines allow for the variation of the orientation of fibres along a lamina and in this way one obtains a composite laminated panel where the stiffness varies from point to point. Forced,geometrically non-linear,periodic vibrations of thin variable stiffness composite laminated（VSCL） plates are analysed in

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Journal of Rare Earths 2006年第3期24卷 298-301页

作者：张福俊徐征刘玲孟立建 Key Laboratory of Luminescence and Optical Information Ministry of Education Institute of Optoelectronic Technology Beijing Jiaotong University Beijing 100044 China Key Laboratory of Luminescence and Optical Information Ministry of Education Institute of Optoelectronic Technology Beijing Jiaotong University Beijing 100044 ChinaDepartmento de Fisica Instituto Superior de Engenharia do Porto 4200-072 Porto Protugal departmento de Fisica Instituto Superior de engenharia do Porto 4200-072 Porto Protugal

The acceleration ability of electrons in SiO2 and ZnS was compared through the variation of emission intensity based on ZnS ： Er electroluminescence during the reverse of polarity of sinusoidal voltage. In order to avoid the influence of work function of electrode, cathodal and anodal materials were ITO （indium tin oxide）. The ratio of maximum emission intensity under positive and negative half period is 2.18. This result demonstrates that the electron acceleration ability of SiO2 is 2.18 times stronger than that of ZnS.

关键词： electron acceleration rare earths

Spectroscopic investigations on Yb^3+ doped and Pr^3+/Yb^3+ codoped tellurite glasses for photonic applications

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Journal of Rare Earths 2021年第1期39卷 33-42,I0002页

作者： M.Seshadri M.J.V.Bell V.Anjos Y.Messaddeq Grupo de engenharia e Espectroscopia de Materiais Departamento de Fisica-ICEUniversidade Federal de Juiz de ForaJuiz de ForaMG36036-900Brazil Centre d'Optique Photonique et Laser2375 Rue de la TerrasseUniversite LavalQuebecQCG1V 0A6Canada

In this work we repo rt on structural and spect roscopic properties of Yb^3+doped and Pr^3+/Yb^3+co-doped TeO2-Bi2 O3-ZnO-Li2 O-Nb2 O5(TBZLN)tellurite *** and stretching modes of TeO2 and Te-OH bond(strong and weak)were analysed from the deconvolution of observed Raman and FT-IR *** on the absorption measurements,the energy bands of Yb^3+and Pr^3+ions are *** spectroscopic properties for the radiative transitions of Yb^3+and Pr^3+ions were reported using McCumber and Judd-Ofelt *** emission bands originating from 3 P1 and 3 P0 to lower lying levels of Pr^3+were registered under 447 nm *** emission band around 1334 nm assigned to the Pr3:1 G4→3 H5 was observed when excited at 980 *** stimulated emission cross-section(σemi(λ))and effective linewidth(Δλeff)for the 3 P1→3 H6,3 P1→3 H5,3 P0→3 H6,3 P0→3 F2,3 P1→3 F3,3 P1→3 F4,3 P0→3 F4 and 1 G4→3 H5 transitions of Pr^3+are *** luminescence in Pr^3+/Yb^3+codoped glass upon 980 nm excitation was *** resonant transfer processes between Yb^3+and Pr^3+ions are presented and *** chromaticity co-ordinates were also evaluated from the visible emission spectra showing that Pr^3+/Yb^3+co-doped glass may be suitable for the development of yellow-orange(λexc=447 nm)and near white light(λexc=980 nm)emitting devices in photonics.

关键词： Rare earth ions Tellurite glass Spectroscopic properties Upconversion luminescence

Proposal of a fireproof design code for dwellings against the action of wildland fires

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Resilient Cities and Structures 2023年第3期2卷 104-119页

作者： M.R.T.Arruda A.R.A.Bicelli P.Cantor E.B.Assis F.Branco CERIS Instituto Superior TécnicoUniversidade de LisboaPortugal Escola de engenharia de São Carlos Universidade de São PauloBrazil Instituto Superior Técnico Universidade de LisboaPortugal

This study proposes a concept for the development of a fireproof design code for the verification of dwellings susceptible to wildfire *** are currently structural codes for the design of buildings when subjected to indoor fires,outside fires that grow on the facade of buildings,and even fires in an accident situation due to ignitions with hydrocarbons or transportation *** of these security verification specifications are described in EC1:*** current regulation in Portugal uses safety criteria and risk categories that are for indoor fires,therefore is very conservative and may not present an economic fireproof design against the action of *** aim of this work is a straight verification based on natural temperature characteristic curves that simulate wildfire heat flow by convection,radiation,and the deposits of firebrands.

关键词： Structural safety verification Wildfires in dwellings Nominal fires vs natural fires Fireproof construction guidelines

Functionalization of AuMSS nanorods towards more effective cancer therapies

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Nano Research 2019年第4期12卷 719-732页

作者： Carolina F. Rodrigues Telma A. Jacinto Andre F. Moreira Elisabete C. Costa Sonia P. Miguel Ilidio J. Correia CICS-UBI -Centro de Investigagao em Ciencias da Saude Universidade da Beira Interior Covilhd 6200-506 Portugal CIEPQF - departamento de engenharia Quimica Universidade de Coimbra Rua 13 Silvio Lima Coimbra 3030-790 Portugal

The applicatio n of nano particles as selective drug delivery platforms arises as one the most promising therapeutic strategies in the biomedical field. Such systems can encapsulate drugs, prevent its premature degradation, transport and promote the drugs specific delivery to the target site. Among the different nanostructures, gold-core mesoporous silica shell (AuMSS) nanorods have been one of the most explored due to their unique physical and chemical properties. The mesoporous silica biocompatibility, high surface area that can be easily functionalized, tubular pores that can store the drugs, conjugated with the intrinsic capacity of gold nanorod to absorb near-infrared radiation, allows the combination of hyperthermia (i.e., photothermal effect) with drug delivery, making them a nanoplatforms with a huge potential for cancer therapy. Nevertheless, the successful applicati on of AuMSS nanoparticles as an effective can cer nano medicine is hindered by the uncon trolled release of the therapeutic payloads, limited blood circulation time and unfavorable pharmacokinetics. In this review, an overview of the modificati ons performed to improve the AuMSS nano rods applicati on in nanom edicine is provided, highlighting the practical approaches that enhaneed the AuMSS nanorods targeting, responsiveness to different stimuli, and blood circulation time. Further, the basics of AuMSS nano rods syn thesis procedures, gen eral properties, and its applicati on in can cer therapy are also described.

关键词： gold nano rods silica surface modifications targeting cancer

Effect of operating conditions and potassium content on Fischer-Tropsch liquid products produced by potassium-promoted iron catalysts

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Journal of Natural Gas Chemistry 2008年第2期17卷 175-178页

作者： Francisco E.M.Farias Fernando G.Sales Fabiano A.N.Fernandes Universidade Federal do Ceará Departamento de Engenharia QuímicaCampus do PiciBloco 70960455-760 Fortaleza-CEBrazil

The dependencies of Fischer-Tropsch synthesis liquid hydrocarbon product distribution on operating pressure and temperature have been studied over three potassium-promoted iron catalysts with increasing potassium molar content. The study followed an experimental planning and the results were analyzed based on surface response methodology. The effects of different operating conditions and potassium contents on the liquid product distribution were compared based on number average carbon number and dispersion. Results showed that high pressures （25 to 30 arm） favored the production of waxes that could be converted into liquid fuels through hydrocracking, while greater direct selectivity towards diesel was favored by low pressure （20 arm） using catalysts with low potassium to iron molar ratios. The liquid product distribution produced using an iron catalyst with high potassium content presented higher number-average number of carbons when compared to the distribution obtained using an iron catalyst with low potassium content.

关键词： Fischer-Tropsch synthesis liquid fuels iron-based catalyst potassium

Why static bound-state calculations of tetraquarks should be met with scepticism

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Chinese Physics C 2017年第5期41卷 49-53页

作者： George Rupp Eef van Beveren Centro de Fisica e engenharia de Materiais Avancados Instituto Superior Tecnico Universidade de Lisboa P-1049-001 Lisboa Portugal Centro de Fisica da UC Departamento de Fisica Universidade de Coimbra P-3004-516 Coimbra Portugal

Recent experimental signals have led to a revival of tetraquarks,the hypothetical q~2q~2 hadronic states proposed by Jaffe in 1976 to explain the light scalar *** structures with exotic quantum numbers have indeed been observed recently,though a controversy persists as to whether these are true resonances and not merely kinematical threshold enhancements,or otherwise states not of a true q~2q~2 ***,puzzling non-exotic mesons are also often claimed to have a tetraquark ***,the corresponding model calculations are practically always carried out in pure and static bound-state approaches,ignoring completely the coupling to asymptotic two-meson states and unitarity,especially the dynamical effects *** this short paper we argue that these static predictions of real tetraquark masses are highly unreliable and provide little evidence of the very existence of such states.

关键词： meson scalar quark dynamical asymptotic otherwise argue merely decay exotic

Extracellular vesicles from oviductal and uterine fluids supplementation in sequential in vitro culture improves bovine embryo quality

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Journal of Animal Science and Biotechnology 2023年第1期14卷 114-133页

作者： Cláudia Lima Verde Leal Karina Canón-Beltrán Yulia N.Cajas Meriem Hamdi Aracelli Yaryes María Gemma Millán de la Blanca Paula Beltrán-Brena Rosane Mazzarella Juliano Coelho da Silveira Alfonso Gutiérrez-Adán Encina M González Dimitrios Rizos department of Animal Reproduction National Center Institute for Agriculture and Food Research and Technology(CSIC-INIA)28040 MadridSpain. departamento de Medicina Veterinaria Faculdade de Zootecnia e Engenharia de AlimentosUniversidade de Sao Paulo(FZEA-USP)PirassunungaBrazil. Facultad de Ciencias agrarias y Ambientales Programa de Medicina VeterinariaFundacion Universitaria Juan de CastellanosTunjaColombia. Laboratorio de Biotecnologia de la Reproduccion Animal Facultad de Ciencias AgropecuariasUniversidad de Cuenca(UC)EC010205 CuencaEcuador. department of Anatomy and Embryology Veterinary Faculty-Universidad Complutense de Madrid(UCM)MadridSpain.

Background:In vitro production of bovine embryos is a well-established technology,but the in vitro culture(IVC)system still warrants improvements,especially regarding embryo *** study aimed to evaluate the effect of extracellular vesicles(EVs)isolated from oviductal(OF)and uterine fluid(UF)in sequential IVC on the development and quality of bovine *** were cultured in SOF supplemented with either BSA or EVs-depleted fetal calf serum(dFCS)in the presence(BSA-EV and dFCS-EV)or absence of EVs from OF(D1 to D4)and UF(D5 to D8),mimicking in vivo *** from oviducts(early luteal phase)and uterine horns(mid-luteal phase)from slaughtered heifers were isolated by size exclusion *** rate was recorded on days 7-8 and their quality was assessed based on lipid contents,mitochondrial activity and total cell numbers,as well as survival rate after *** mRNA abundance for lipid metabolism-related transcripts and levels of phosphorylated hormonesensitive lipase(pHSL)proteins were also ***,the expression levels of 383 miRNA in OF-and UF-EVs were assessed by ***:Blastocyst yield was lower(Pdecreased in dFCSEV(P0.05).Lipid metabolism transcripts were affected by EVs and showed interaction with type of protein source in medium(PPARGC1B,LDLR,CD36,FASN and PNPLA2,Pdevelopment but improves blast

关键词： Cattle Cryopreservation Embryo development Exosomes Lipid metabolism miRNAs Oviduct Uterus

DC Plasma Technology Applied to Powder Metallurgy: an Overview

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Plasma Science and Technology 2013年第1期15卷 70-81页

作者： A. N. KLEIN R. P. CARDOSO H. C. PAVANATI C. BINdeR A. M. MALISKA G. HAMMES D. FUSAO A. SEEBER S. F. BRUNATTO J. L. R. MUZART LabMat (Materials Laboratory) Departamento de Engenharia Mec~nica Universidade Federal de Santa Catarina (UFSC) 88040-900 FlorianSpolis - SC Brazil departamento de engenharia Mecanica Universidade Federal do Parana (UFPR) 81531-990 Curitiba- PR Brazil departamento Academico de Metal-Mecanica Instituto Federal de Santa Catarina (IFSC) 88020-300 Florianopolis - SC Brazil Universidade Tecnologica Federal do Parana (UTFPR) 84016-210 Ponta Grossa - PR Brazil Centro de Ciencia e Tecnologia Universidade de Caxias do Sul 95070-560 Caxias do Sul- RS Brazil

DC plasma is a very promising technology for processing different materials, and is becoming especially interesting when low environmental impact and high-performance treatments are needed. Some of the intrinsic characteristics of DC plasma technology, which make it suitable for powder metallurgy （PM） and powder injection molding （PIM） parts production, are low- pressure processing and plasma environment high reactivity. Moreover it can be considered as a highly competitive green technology. In this work, an overview of some of the important DC plasma techniques applied to PM and PIM parts processing is presented. Emphasis is given to the descriptions of the main characteristics and the technique potentials of plasma-assisted nitriding, plasma-assisted thermal debinding, plasma-assisted sintering, and simultaneously plasma-assisted sintering and surface alloying. The aspects presented and discussed in this paper indicate that DC plasma processes are promising and competitive techniques for PM and PIM parts processing.

关键词： powder metallurgy DC glow discharge plasma nitriding plasma sintering,plasma-assisted thermal debinding surface alloying