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Demonstration of laser pulse amplification by stimulated Brillouin scattering

High Power Laser Science and Engineering 2014年第4期 46-51页

作者： E.Guillaume K.Humphrey H.Nakamura r.M.G.M.Trines r.Heathcote M.Galimberti Y.Amano D.Doria G.Hicks E.Higson S.Kar G.Sarri M.Skramic J.Swain K.Tang J.Weston P.Zak E.P.Alves r.a.fonseca F.Fi ′uza H.Habara K.A.Tanaka r.Bingham M.Borghesi Z.Najmudin L.O.Silva P.A.Norreys Laboratoire d'Optique Appliqu′ee Ecole PolytechniquePalaiseau 91128 France STFC rutherford Appleton Laboratory Didcot Oxon OX11 0QX United Kingdom University of Strathclyde Glasgow G11XQ United Kingdom Blackett Laboratory Imperial College London Prince Consort RoadLondon SW7 2BZ United Kingdom Graduate School of Engineering Osaka University Queens University Belfast Belfast BT7 1NN United Kingdom University of Oxford Parks RoadOxford OX1 3PU United Kingdom

The energy transfer by stimulated Brillouin backscatter from a long pump pulse(15 ps) to a short seed pulse(1 ps)has been investigated in a proof-of-principle demonstration experiment. The two pulses were both amplified in different beamlines of a Nd:glass laser system, had a central wavelength of 1054 nm and a spectral bandwidth of 2 nm, and crossed each other in an underdense plasma in a counter-propagating geometry, off-set by 10?. It is shown that the energy transfer and the wavelength of the generated Brillouin peak depend on the plasma density, the intensity of the laser pulses, and the competition between two-plasmon decay and stimulated raman scatter instabilities. The highest obtained energy transfer from pump to probe pulse is 2.5%, at a plasma density of 0.17 ncr, and this energy transfer increases significantly with plasma density. Therefore, our results suggest that much higher efficiencies can be obtained when higher densities(above0.25ncr) are used.

关键词： laser–plasma interactions optical pulse generation and compression stimulated Brillouin and raman scattering ultra-fast optical processes

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Nanoparticles embedded into glass matrices:glass nanocomposites

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Frontiers of Materials Science 2022年第3期16卷 1-81页

作者： Javier fonseca Department of Chemical Engineering Northeastern UniversityBoston 02115USA

research on glass nanocomposites(GNCs)has been very active in the past *** have attracted—and still do—great interest in the fields of optoelectronics,photonics,sensing,electrochemistry,catalysis,biomedicine,and *** this review,the potential applications of GNCs in these fields are briefly described to show the reader the possibilities of these *** most important synthesis methods of GNCs(melt-quenching,sol-gel,ion implantation,ion-exchange,staining process,spark plasma sintering,radio frequency sputtering,spray pyrolysis,and chemical vapor deposition techniques)are extensively *** major aim of this review is to systematize our knowledge about the synthesis of GNCs and to explore the mechanisms of formation and growth of NPs within glass *** size-controlled preparation of NPs within glass matrices,which remains a challenge,is essential for advanced ***,a thorough understanding of GNC synthesis techniques is expected to facilitate the preparation of innovative GNCs.

关键词： glass nanocomposites melt-quenching sol-gel ion implantation ion-exchange

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Direct oxidation of methane at low temperature using Pt/C,Pd/C,Pt/C-ATO and Pd/C-ATO electrocatalysts prepared by sodium borohydride reduction process

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燃料化学学报 2018年第9期46卷 1137-1145页

作者： J.Nandenha E.H.Fontes r.M.Piasentin F.C.fonseca A.O.Neto Instituto de Pesquisas Energéticas e Nucleares IPEN/CNEN-SPAv.Prof.Lineu Prestes2242 Cidade UniversitáriaCEP 05508-000Sao PauloSPBrazil

The main objective of this paper was to characterize the voltammetric profiles of the Pt/C,Pt/C-ATO,Pd/C and Pd/CATO electrocatalysts and study their catalytic activities for methane oxidation in an acidic electrolyte at 25 ℃ and in a direct methane proton exchange membrane fuel cell at 80 ℃. The electrocatalysts prepared also were characterized by X-ray diffraction( XrD) and transmission electron microscopy( TEM). The diffractograms of the Pt/C and Pt/C-ATO electrocatalysts show four peaks associated with Pt face-centered cubic( fcc) structure,and the diffractograms of Pd/C and Pd/C-ATO show four peaks associated with Pd face-centered cubic( fcc) structure. For Pt/C-ATO and Pd/C-ATO,characteristic peaks of cassiterite( SnO_2) phase are observed,which are associated with Sb-doped SnO_2( ATO) used as supports for electrocatalysts. Cyclic voltammograms( CV) of all electrocatalysts after adsorption of methane show that there is a current increase during the anodic scan. However,this effect is more pronounced for Pt/C-ATO and Pd/C-ATO. This process is related to the oxidation of the adsorbed species through the bifunctional mechanism,where ATO provides oxygenated species for the oxidation of CO or HCO intermediates adsorbed in Pt or Pd sites. From in situ ATr-FTIr( Attenuated Total reflectance-Fourier Transform Infrared) experiments for all electrocatalysts prepared the formation of HCO or CO intermediates are observed,which indicates the production of carbon dioxide. Polarization curves at 80 ℃in a direct methane fuel cell( DMEFC) show that Pd/C and Pt/C electroacatalysts have superior performance to Pd/C-ATO and Pt/C-ATO in methane oxidation.

关键词： sodium borohydride reduction process Pt/C-ATO and Pd/C-ATO electrocatalysts methane oxidation acidic electrolytes polarization curves

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Sao Francisco-Congo Craton break-up delimited by U-Pb-Hf isotopes and trace-elements of zircon from metasediments of the Aracuaí Belt

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Geoscience Frontiers 2019年第2期10卷 611-628页

作者： Mathias Schannor Cristiano Lana Marco A.fonseca Applied Isotope research Group Department of GeologyUniversidade Federal de Ouro Preto

Detrital zircon U-Pb geochronology combined with Hf isotopic and trace element data from metasedimentary rocks of the Aracuai Belt in southeastern Brazil provide evidence for break-up of the Congo-Sao Francisco Craton. The U-Pb age spectra of detrital zircons from metasediments of the rio Doce Group(rDG) range from 900-650 Ma and define a maximum depositional age of ca. 650 Ma. Zircon trace element and whole rock data constrain an oceanic island arc as source for the deposition setting of the protoliths to the metasediments. Zircon ε_(Hf)(t) values from these rocks are positive between +1 and +15, supporting previous evidence of a Neoproterozoic extensional phase and oceanic crust formation in a precursor basin to the Aracuai Belt. recrystallization of detrital zircon at ca. 630 Ma is compatible with a regional metamorphic event associated with terrane accretion to the Paleoproterozoic basement after transition from an extensional to a convergent regime. The juvenile nature, age spectra and trace element composition recorded in detrital zircons of metasediments from the Aracuai Belt correspond with zircons from metasedimentary rocks and oceanic crust remnants of other orogenic belts to its south. This suggests that rifting and oceanic crust formation of the entire orogenic system, the so-called Mantiqueira Province, was contemporaneous, most likely related to the opening of a large ocean. It further indicates that the cratonic blocks involved in the orogenic evolution of the Mantiqueira Province were spatially connected as early as 900 Ma.

关键词： Detrital zircon U-Pb geochronology Lu-Hf isotopes Trace elements Aracuaí Belt

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Photoluminescent Tb^(3+)-based metal-organic framework as a sensor for detection of methanol in ethanol fuel

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Journal of rare Earths 2019年第3期37卷 225-231页

作者： ramon r.F.fonseca rafael D.L.Gaspar Ivo M.raimundo Jr. Priscilla P.Luz Department of Chemistry Federal University of Espírito Santo Institute of Chemistry University of Campinas

The sensing capability of a Tb^(3+)-metal-organic framework, based on its photoluminescence, was used for detection of methanol in ethanol fuel. It was synthesized using terbium and trimesic acid as a metal ion center and ligand, respectively. Powder X-ray diffraction, infrared spectroscopy, thermogravimetric analysis and scanning electron microscopy were employed to characterize the synthesized MOF-76 structural features. According to the results, MOF-76 was successfully obtained with minor synthetic modification and its activated form(named TbTMA) was tested as a sensor for methanol. Tb^(3+) luminescence intensity increases as the methanol concentration in ethanol fuel also increases and the water content does not affect this response. Our findings indicate TbTMA as an appropriate sensor for evaluating ethanol fuel adulteration by methanol addition above the allowed limit.

关键词： Lanthanide Metal-organic frameworks Luminescence Ethanol fuel Sensor Adulteration

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Approach to a patient with cardiac amyloidosis

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Journal of Geriatric Cardiology 2019年第7期16卷 567-574页

作者： Christopher Strouse Alexandros Briasoulis rafael fonseca Yogesh Jethava Department of Internal Medicine Division of HematologyOncologyand Blood and Marrow TransplantationUniversity of IowaIowa CityIAUSA Cardiomyopathy Section Cardiology DivisionUniversity of IowaIowa CityIowaUSA Bone Marrow Transplant Program Mayo ClinicPhoenixArizonaUSA

1 Introduction Cardiac amyloid(CA)is characterized by inexorably progressive heart failure making early diagnosis and treatment *** article will review the pathophysiology,clinical presentation,diagnosis,prognostication and treatment of patients with CA.2 Pathophysiology CA is the result of extracellular deposition of a misfolded protein into cardiac tissue,forming insoluble aggregations of rigid,nonbranching 10 nm wide *** causes impaired cardiac function by disrupting cardiac architecture,direct myotoxicity and ischemic injury secondary to infiltration of intramyocardial vessels.

关键词： Cardiac amyloidosis Heart failure The elderly

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Trial eligibility in advanced hepatocellular carcinoma: Does it support clinical practice in underrepresented subgroups?

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World Journal of Gastroenterology 2021年第24期27卷 3429-3439页

作者： Federico Piñero Leonardo Gomes da fonseca Hepatology and Liver Unit Hospital Universitario AustralSchool of MedicineAustral UniversityBuenos Aires B1629HJArgentina Clinical Oncology Insituto do Cancer do Estado de São PauloUniversity of São PauloSão Paulo 05403-000Brazil

Although hepatocellular carcinoma is considered a highly lethal malignancy,recent therapeutic advances have been achieved during the last 10 *** scenario resulted in an unprecedented improvement in survival for patients with advanced hepatocellular carcinoma,almost reaching 20-26 mo of overall survival after first-second line sequential *** advent of the combination of atezolizumab with bevacizumab showed,for the first time,superiority over sorafenib with improvement in overall ***,first and second-line trials were correctly based on the premise that a strict selection of patients enhances the power to capture the positive effect of treatment by excluding competing risks for mortality such as liver failure,decompensated cirrhosis or other underlying medical *** a result,the inclusion criteria used in clinical trials do not support the use of novel therapies in several real-world scenarios involving underrepresented subgroups,such as patients with unpreserved liver function,other comorbid conditions,a history of solid-organ transplantation,autoimmune disorders and those with a high risk of *** present text aims at discussing treatment strategies in these subgroups.

关键词： Eligibility Systemic therapies End-stage Hepatocellular carcinoma

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resource management at the network edge for federated learning

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Digital Communications and Networks 2024年第3期10卷 765-782页

作者： Silvana Trindade Luiz F.Bittencourt Nelson L.S.da fonseca Institute of Computing State University of CampinasCampinasBrazil

Federated learning has been explored as a promising solution for training machine learning models at the network edge,without sharing private user *** limited resources at the edge,new solutions must be developed to leverage the software and hardware resources as the existing solutions did not focus on resource management for network edge,specially for federated *** this paper,we describe the recent work on resource manage-ment at the edge and explore the challenges and future directions to allow the execution of federated learning at the *** such as the discovery of resources,deployment,load balancing,migration,and energy effi-ciency are discussed in the paper.

关键词： resource management Edge computing Federated learning Machine learning

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Basic density, extractive content and moisture sorption properties of Pinus pinaster wood infected with the pinewood nematode, Bursaphelenchus xylophilus

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Journal of Forestry research 2015年第1期26卷 233-240页

作者： Valeria reva Luís fonseca José L.Lousada Isabel Abrantes António r.Figueiredo Domingos X.Viegas Centre of Forest Fire Studies Association for the Development of Industrial Aerodynamics(CEIF/ADAI) Rua Pedro Hispano CFE-Centre for Functional Ecology Department of Life SciencesUniversity of Coimbra Centre for research and Technology of Agro-Environment Biological Sciences(CITAB) UTADQuinta dos Prados Apartado

The pinewood nematode（PWN）, Bursaphelenchus xylophilus, has become one of the most severe threats to pine forest worldwide. Nematodes, migrating through resin canals and feeding on the living cells, induce rapid metabolic changes in ray parenchyma cells, create cavitation areas, decrease xylem water content and oleoresin exudation, and cause necrosis of parenchyma and cambial cells. This study focused on the impact of PWN infection on technological parameters of wood and evaluated the impact of anatomic and biochemical incidences of tree defense reactions on basic density, extractive content and moisture sorption properties of Pinus pinaster *** of infected and uninfected wood were *** presence of nematodes reduced wood basic density by2 % and decreased the total content of extractives in infected wood as compared with uninfected（5.98 and8.90 % of dry wood mass, respectively）. Extractives in infected trees had inverse distribution along the trunk as compared with uninfected trees. The adsorption isotherms for infected and uninfected wood had similar *** recorded differences（some statistically significant） in the equilibrium moisture content of infected and uninfected wood under varying environmental conditions. Despite the verified differences in wood basic density, extractive content and moisture sorption properties, the overall conclusion is that the PWN had a slight impact on these characteristics of wood.

关键词： Pinewood nematode Wood density Extractives Equilibrium moisture content Economic impact

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Automatic detection and evaluation of sugarcane planting rows in aerial images

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Information Processing in Agriculture 2023年第3期10卷 400-415页

作者： Bruno Moraes rocha Afonso Ueslei da fonseca Helio Pedrini Fabrızzio Soares Instituto de Informa´tica Universidade Federal de Goia´sGoiaˆnia 74690-900GOBrazil Institute of Computing University of CampinasCampinas 13083-852SPBrazil

Sugarcane planting is an important and growing activity in ***,several techniques have been developed over the years to maximize crop productivity and profit,amongst them,processing of sugarcane field *** this sense,this research aims to identify and analyze crop rows and measure their gaps from aerial images of sugarcane *** this,a small remotely Piloted Aircraft captured the images,generating orthomosaics of the areas for ***,each orthomosaic is classified with the K-Nearest Neighbor algorithm to segment regions of *** row orientation is estimated using the rGB gradient *** operations and computational geometry models are then used to detect and map rows and gaps along the planting row *** evaluate the results,crop rows are mapped and compared to manually taken *** technique obtained an error smaller than 2%when compared to gap length in crop rows from an orthomosaic with the area of 8.05 ha(ha).The proposed approach can map the positioning of the automatically generated row segments appropriately onto manually created ***,our method also achieved similar results when confronted with a manual technique for differing growth stages(40 and 80 days after harvest)of the sugarcane *** proposed method presents a great potential to be adopted in sugarcane planting monitoring。

关键词： Sugarcane Planting rows Aerial Images remotely Piloted Aircraft

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