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Frontiers of Mechanical Engineering 2015年第3期10卷 221-232页

作者： pedro BOCCA Facultad de Ingenieria Universidad Nacional de San Juan San Juan5400 Argentina

In the mechanized harvest of vines, grape berries are detached through the vibration to the structure supporting the clusters. According to the kind of guide selected, the clusters require one or two vibration directions in the structure. For guiding in parral structures, vibration is necessary in two directions or planes： One perpendicular to the other. The guide branches producing the clusters develop in these planes, and the guiding is called H-guiding. Mechanism theory indicates that a mechanism has as many degrees of freedom as its actuators, and an actuator is needed to achieve a certain vibration. Having the smallest number of possible actuators is beneficial in reducing moving parts and achieving more compact and easily controllable mecha- nisms. In this case, a single degree-of-freedom mechanism is proposed. It is capable of generating vibrations on two planes： One perpendicular to the other. This mechanism is the sum of two link mechanisms on perpendicular planes with a common outlet located at the output rod of the mechanism where the actuator is found. As the distance between the soil and the elements containing the clusters is not constant, a system has been designed to measure the accelerations at the bars and the rocker to validate the acceleration values that detach the grape berries in a prototype in a lab experiment, to ensure that the acceleration needed for pulling the grape berries are produced at any contact point of the bar.

关键词： harvest mechanisms one DOF vibration

High-Efficiency DC-DC Converter for Large Input-Voltage Fluctuations in Solar Applications

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Chinese Journal of Electronics 2015年第3期24卷 502-507页

作者： AGUILLON-GARCIA Jacobo BANUELOS-SANCHEZ pedro SIST Sun Yat-sen University

In the solar energy systems the solar irradiance variation is partially engaged, limiting the converter’s transformation rate for a certain input amount and leaving the rest of energy unconverted. In order to utilize at its maximum the energy provided from a Photovoltaic(PVP) system, this manuscript proposed a topology that can cope with marginal input voltage variations from 60V(DC) up to 1050V(DC) for a steady output voltage of 700V(DC). This output voltage value is suitable for any interlink post-regulation architecture. Based on previous observations, this paper presents a wide-input voltage high-efficiency non-isolated single-control topology. Analysis, operating stages, simulations and experimental results for a 3k W prototype are presented.

关键词： DC-DC power converters Energy conversion Photovoltaic system Power conditioning Solar generation

Colletotrichum species and complexes:geographic distribution,host range and conservation status

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Fungal Diversity 2021年第5期110卷 109-198页

作者： pedro Talhinhas Riccardo Baroncelli LEAF-Linking Landscape EnvironmentAgriculture and Food-Research CentreAssociated Laboratory TERRAInstituto Superior de AgronomiaUniversidade de LisboaTapada da Ajuda1349-017 LisbonPortugal Department of Agricultural and Food Sciences(DISTAL) University of BolognaBolognaItaly

The taxonomy of the genus Colletotrichum has undergone tremendous changes over the last decade,with over 200 species being currently recognised and species complexes being informally used to cluster those *** of these species are important plant pathogens,some rather polyphagous and others host-specific,but several occur seldomly and some may in fact be ecologically *** mainly on literature from the past decade,in this work we review the occurrence,geographic distribution and host spectrum of currently recognised Colletotrichum species under phylogenetic,pathologi-cal/agronomic and ecological perspectives,providing a list arranged by Colletotrichum species and species complexes.A total of 257 species are listed and grouped into 15 species *** this work we have recorded 1353 unique host species-Colletotrichum species association records from 720 hosts,with the Fabaceae as the family with higher number of hosts(52 host species)but with the Rosaceae as the family with the highest number of host species-Colletotrichum species association records(118 association records).According to occurrence data,88 species are common in nature,128 were considered as data deficient and 41 are threatened,some of which are likely extinct from nature and preserved only in cul-ture *** species are relevant plant pathogens,in some cases geographically confined and thus of potential quarantine *** on the major changes that occurred on Colletotrichum taxonomy over the last decade,this work provides a comprehensive overview of occurrence data of Colletotrichum species,compiling host range and geographical distribution,with relevance for plant pathology and conservation *** current taxonomic framework in Colle-totrichum is revealing numerous species but poses challenges to the employment of standard criteria for the evaluation of biological conservation of these *** advocate that conservation mycology and taxonomy should

关键词： Colletotrichum Species complex Taxonomy Host range Geographic distribution Conservation mycology

Pleistocene Birds of Gruta da Furninha （Peniche-Portugal）： A Paleontological and Paleoenvironmental Aproach

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Journal of Environmental Science and Engineering(A) 2017年第10期6卷 502-509页

作者： Silverio Domingues figueiredo pedro Proenga Cunha Femanda Sousa Telmo Pereira Americo Rosa Polytechnic Institute of Tomar Quinta do Contador Estrada da Serra 2300-313 Tomar Portugal Portuguese Center of Geo-History and Prehistory Largo de Sao Caetano Golega 2150-265 Portugal Geosciences Center--Univ. of Coimbra Rua Silvio Lima Univ. Coimbra Coimbra 3030-790 Portugal MARE--Marine and Environmental Sciences Centre Department of Earth Sciences Coimbra University Rua Silvio LimaCoimbra 3030- 790 Portugal ICArEHB--Interdisciplinary Center for Archaeology and Evolution of Human Behaviour Human and Social Sciencies Faculty University of Algarve Campus de Gambelas 8005-139 Faro Portugal

The cave-site of Gruta da Furninha is a coastal karstic cavity. In the late 19th century, excavation of the sedimentary infill of the cave allowed the identification of two lithostratigraphic units： a Holocene one dominated by sands, containing human bones and a Neolithic industry; and a Late Pleistocene one, containing a diverse set of fossils set and Paleolithic artifacts. This study mainly focuses on taphonomic and palaeoenvironmental data concerning the Pleistocene bird bones that were collected from six layers （at 11 m and 6.7 m asl）. A main result of this study was the discovery of a left humerus fragment, with osteological features of the Alcidae family; from comparison with upper arms of distinct species of this family, it was concluded that this fossil belongs to Penguin impennis. The Pleistocene birds of the Furninha cave were also compared with the avifauna that currently occurs in the region of Peniche peninsula and a climate and environmental interpretation of the Pleistocene fossiliferous set is provided.

关键词： Birds Pleistocene marine caves Portugal.

Weighted binary relations involving core-EP inverse

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Frontiers of Mathematics in China 2020年第4期15卷 685-699页

作者： Yuefeng GAO Jianlong CHEN pedro PATRICIO College of Science University of Shanghai for Science and TechnologyShanghai 200093China School of Mathematics Southeast UniversityNanjing 210096China CMAT-Centro de Matematica Universidade do MinhoBraga 4710-057Portugal

We study a new binary relation defined on the set of rectangular complex matrices involving the weighted core-EP inverse and give its *** relation becomes a ***,one-sided preorders associated to the weighted core-EP i... 详细信息

关键词： Weighted core-EP inverse core-EP inverse pseudo core inverse pre-order

Dynamics of phosphorus in sediments of a naturally acidic lake

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International Journal of Sediment Research 2013年第1期28卷 90-102页

作者： Temporetti pedro Snodgrass KIMBERLEY pedrozo FERNANDO Centro Regional Universitario Bariloche Universidad Nacional del ComahueCONICETQuintral 12508400 BarilocheArgentina Staff Environmental Engineer Water and Environmental Technologies 480 East Park StreetSuite 200 ButteMT59701MontanaEEUU INIBIOMA Centro Regional Universitario BarilocheUniversidad Nacional del ComahueCONICETQuintral 12508400 BarilocheArgentina

The mechanisms which controls the fixation and/or release of P in sediment of an extremely acidic lake（pH = 2.0 to 3.0） and its response to the influence of eutrophic urban waste water were *** results,in the chemical composition,in the mineralogy of the sediment and in the material as obtained from sediment traps,show that the lake sediments are mainly volcanic material reflecting volcanic features of the *** sedimentation rate calculated for the lake(2.5×10;mg m;day;) was higher than that observed in other similar glacial lakes in both Andean Patagonia and also elsewhere in the *** Total Phosphorus concentration in sediments was higher than figures reported by other authors for mining acid lakes,and the main fraction of P was found associated with organic *** was no control by Fe or Al on P,because both are in solution at pH < *** was concluded that changes in the natural input of nutrients（derivatives of Copahue volcano fluid,the discharge of sewage,or basin run-off） are responsible for a high concentration of SRP and N-NH;in the *** experiments showed that sediments have no ability to retain phosphorus and a continuous release of P from the sediments into the water column was *** assays where the pH was artificially increased showed that the P still remains in solution until at least pH *** was concluded that changes in the natural input of nutrients due to:1) the volcanic fluids,2) the increase in sewage charges,or 3) surface runoff upstream,maintain a high trophic state with high concentrations of dissolved P and N-NH;,although the threshold of neutral pH in the lake is *** study will enable a better understanding about of the mechanism of release/fixation of phosphorus in acidic sediments in order to assist in making decisions regarding the conservation and management of this natural environment.

关键词： Sediments Phosphorus release Acidic lake

Lessons learnt from a deep excavation for future application of the observational method

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Journal of Rock Mechanics and Geotechnical Engineering 2018年第3期10卷 468-485页

作者： Raul Fuentes Anton Pillai pedro Ferreira School of Civil Engineering University of LeedsLeedsLS2 9JTUK Ove Arup and Partners 13 Fitzroy StreetLondonW1T 4BQUK Department of Civil Environmental&Geomatic EngineeringUniversity College LondonChadwick BuildingGower StreetLondonWC1E 6BTUK

This paper draws lessons learnt from a comprehensive case study in overconsolidated clay. Apart from the introduction of the case study, including field measurements, the paper draws on the observations and a three-dimensional（3 D） numerical analysis to discuss the implications of observations in the application of the observational method（OM） in the context of the requirements of EUROCODE 7（EC7）.In particular, we focus on corner effects and time-dependent movements and provide initial guidance on how these could be considered. Additionally, we present the validation of a new set of parameters to check that it provides a satisfactory compliance with EC7 as a set of design parameters. All these findings and recommendations are particularly important for those who want to use the OM in similar future projects.

关键词： Deep excavation Basement Ground movements Wall movements Retaining wall Corner effects Time-dependent movements

Meteorological drought features in northern and northwestern parts of Mexico under different climate change scenarios

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Journal of Arid Land 2017年第1期9卷 65-75页

作者： Carlos ESCALANTE-SANDOVAL pedro NUNEZ-GARCIA Faculty of Engineering National Autonomous University of Mexico Cd. Universitaria Coyoacan 04510 Mexico

Meteorological drought has been an inevitable natural disaster throughout Mexican history and the northern and northwestern parts of Mexico（i.e., the studied area）, where the mean annual precipitation（MAP） is less than 500 mm, have suffered even more from droughts in the past. The aim of this study was to conduct a meteorological drought analysis of the available MAP data（1950–2013） from 649 meteorological stations selected from the studied area and to predict the drought features under the different IPCC-prescribed climate change scenarios. To determine the long-term drought features, we collected 1×10~4 synthetic samples using the periodic autoregressive moving average（PARMA） model for each rainfall series. The simulations first consider the present prevailing precipitation conditions（i.e., the average from 1950 to 2013） and then the precipitation anomalies under IPCC-prescribed RCP 4.5 scenario and RCP 8.5 scenario. The results indicated that the climate changes under the prescribed scenarios would significantly increase the duration and intensity of droughts. The most severe impacts may occur in the central plateau and in the Baja California Peninsula. Thus, it will be necessary to establish adequate protective measures for the sustainable management of water resources in these regions.

关键词： meteorological drought synthetic simulation climate change water stress evapotranspiration

On the Restricted Arc-connectivity of s-geodetic Digraphs

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Acta Mathematica Sinica,English Series 2010年第10期26卷 1865-1876页

作者： Camino BALBUENA pedro GARCíA-VZQUEZ Departament de Matemàtica Aplicada Ⅲ Universitat Politècnica de Catalunya Departamento de Matemática Aplicada I Universidad de Sevilla E.T.S. de Arquitectura

For a strongly connected digraph D the minimum ,cardinality of an arc-cut over all arc-cuts restricted arc-connectivity λ′（D） is defined as the S satisfying that D - S has a non-trivial strong component D1 such that D - V（D1） contains an arc. Let S be a subset of vertices of D. We denote by w＋（S） the set of arcs uv with u ∈ S and v S, and by w-（S） the set of arcs uv with u S and v ∈ S. A digraph D = （V, A） is said to be λ′-optimal if λ′（D） =ξ′（D）, where ξ′（D） is the minimum arc-degree of D defined as ξ（D） = min {ξ′（xy）： xy ∈ A}, and ξ′（xy） = min（｜ω＋（{x,y}）｜, ｜w-（{x,y}）｜, ｜w＋（x） ∪ w- （y）｜, ｜w- （x） ∪ω＋（y）｜}. In this paper a sufficient condition for a s-geodetic strongly connected digraph D to be λ′-optimal is given in terms of its diameter. Furthermore we see that the h-iterated line digraph Lh（D） of a s-geodetic digraph is λ′-optimal for certain iteration h.

关键词： Restricted arc-connectivity arc-cut diameter s-geodetic digraph line digraph

Abiotic drivers shape seed inputs and outputs in a tropical wetland on Croton trinitatis population

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Ecological Processes 2022年第1期11卷 65-77页

作者： Francielli Bao Arnildo Pott pedro Manuel Villa Centro de Avaliação da Biodiversidade Pesquisa e Conservação do Cerrado(CBC)Instituto Chico Mendes de Conservação da Biodiversidade(ICMBio)BrasíliaDF 70670-350Brazil Programa de Pós-Graduação em Biologia Vegetal Instituto de BiociênciasUniversidade Federal de Mato Grosso do SulCampo GrandeMS 79070-900Brazil Programa de Pós-Graduacão em Botânica Departamento de Biologia VegetalUniversidade Federal de ViçosaViçosaMG 36570-900Brazil Fundación para la Conservación de la Biodiversidad Mérida 7101Venezuela

Background:Predicting how natural and anthropogenic drivers shape different ecological indicators,such as plant populations along environmental gradients,can be a relevant tool for establishing management and conservation criteria of tropical *** aimed to assess the effects of seasonal flood disturbance,type of grasslands and topographical conditions on Croton trinitatis population distribution in a tropical ***:The study was carried out in a seasonally flooded grassland(Central-West Brazil).We conducted samplings of soil on the dry and flood hydrophases of the *** took the samples in eight seasonal ponds,with 1 km interval between *** were marked during the flood period,observing the water level,one in the lowest zone,in the middle of the pond=low(ca.60 cm deep),one at the pond edge=mid(ca.30 cm deep)and one in the higher zone,on the external part=high(ca.1 cm deep).Results:The results showed that the topography,seasonality,and types of grassland determine differences in the abundance patterns of adult plants and seedlings,and seed bank and seed *** abiotic factors can shape plant population-related ecological processes and patterns,with outputs(germination and predation)and inputs(local dispersion and from neighbouring areas)of proportional seeds for the population maintenance in this ***:We emphasize the importance of these findings,to show that abiotic factors are not the only ones to be considered in ecological studies of distribution and structuring of populations in habitats with extreme seasonal events.

关键词： Environmental filter Flood disturbance Pantanal Population ecology Seasonal change Seed predation Seedling Soil seed bank