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On the unsteady motion and stability of a heaving airfoil in ground effect

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Acta Mechanica Sinica 2011年第2期27卷 164-178页

作者： juan Molina david Angland School of Engineering Sciences University of Southampton Southampton SO17 1BJ UK

This study explores the fluid mechanics and force generation capabilities of an inverted heaving airfoil placed close to a moving ground using a URANS solver with the Spalart-Allmaras turbulence model. By varying the mean ground clearance and motion frequency of the airfoil, it was possible to construct a frequency-height diagram of the various forces acting on the airfoil. The ground was found to enhance the downforce and reduce the drag with respect to freestream. The unsteady motion induces hysteresis in the forces’ behaviour. At moderate ground clearance, the hysteresis increases with frequency and the airfoil loses energy to the flow, resulting in a stabilizing motion. By analogy with a pitching motion, the airfoil stalls in close proximity to the ground. At low frequencies, the motion is unstable and could lead to stall flutter. A stall flutter analysis was undertaken. At higher frequencies, inviscid effects overcome the large separation and the motion becomes stable. Forced trailing edge vortex shedding appears at high frequencies. The shedding mechanism seems to be independent of ground proximity. However, the wake is altered at low heights as a result of an interaction between the vortices and the ground.

关键词： Oscillating airfoil · Flutter · Wing in ground effect · Vortex shedding

Lifestyles of Older Adults in Castilla-La Mancha(Spain):Influence of Sex,Age,and Habitat

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Fudan Journal of the Humanities and Social Sciences 2024年第2期17卷 313-335页

作者： Esther Portal Martínez juan Lirio Castro david Alonso gonzález JoséLuis gómez Ramos University of Castilla-La Mancha Talavera de la ReinaSpain Complutense University MadridSpain

This paper presents the quantitative research results of a comprehensive study titled“Current Profle of Older Adults in Castilla-La Mancha(Spain).”The study aims to understand and describe the characteristics of individuals aged 65 and above within this autonomous region,with a focus on the variables of sex,age,and habitat.A cross-sectional approach was employed,utilizing quantitative methods to collect *** gather information,a customized questionnaire was developed to address the study objectives,covering various aspects such as sociodemographic factors,living conditions,leisure activities,social participation,and cultural *** survey was conducted via telephone,ensuring representation by employing gender quotas,age-group stratifcation,and considerations for habitat size.A representative sample of 1,065 participants was included in the *** fndings reveal a degree of homogeneity in the lifestyles of older adults,with discernible variations infuenced by factors such as sex,habitat,and *** results shed light on the diverse habits and experiences of older adults,emphasizing the signifcance of habitat conditions,social participation,and the aging process.

关键词： Lifestyle habits Older adults Habitat conditions Social participation Aging experience

genoDrawing:An Autoencoder Framework for Image Prediction from SNP Markers

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Plant Phenomics 2023年第4期5卷 816-824页

作者： Federico Jurado-Ruiz david Rousseau juan A.Botía Maria José Aranzana Center for Research in Agricultural genomics(CRAg) 08193 BarcelonaCerdanyolaSpain Universitéd'Angers LARISINRAe UMR IRHS49000 AngersFrance Department of Information and Communication Engineering University of Murcia30071 MurciaSpain IRTA(Institut de Recerca i Tecnologia Agroalimentàries) BarcelonaSpain

Advancements in genome sequencing have facilitated whole-genome characterization of numerous plant species,providing an abundance of genotypic data for genomic *** selection and neural networks(NNs),particularly deep learning,have been developed to predict complex traits from dense genotypic ***,an NN model to extract features from images in an unsupervised manner,has proven to be useful for plant *** study introduces an autoencoder framework,genoDrawing,for predicting and retrieving apple images from a low-depth single-nucleotide polymorphism(SNP)array,potentially useful in predicting traits that are difficult to *** demonstrates proficiency in its task using a small dataset of shape-related *** indicate that the use of SNPs associated with visual traits has substantial impact on the generated images,consistent with biological *** using substantial SNPs is crucial,incorporating additional,unrelated SNPs results in performance degradation for simple NN architectures that cannot easily identify the most important *** proposed genoDrawing method is a practical framework for exploring genomic prediction in fruit tree phenotyping,particularly beneficial for small to medium breeding companies to predict economically substantial heritable *** genoDrawing has limitations,it sets the groundwork for future research in image prediction from genomic *** studies should focus on using stronger models for image reproduction,SNP information extraction,and dataset balance in terms of phenotypes for more precise outcomes.

关键词： Auto Drawing prediction

High-precision chaotic radial basis function neural network model:Data forecasting for the Earth electromagnetic signal before a strong earthquake

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geoscience Frontiers 2022年第1期13卷 364-373页

作者： guocheng Hao juan guo Wei Zhang Yunliang Chen david AYuen School of Mechanical Engineering and Electronic Information China University of GeosciencesWuhan 430074China School of Computer Science China University of GeosciencesWuhan 430074China Department of Mathematics Duke UniversityDurhamNC 27708USA Department of Applied Physics and Applied Mathematics Columbia UniversityNew YorkNY 10027USA

The Earth’s natural pulse electromagnetic field data consists typically of an underlying variation tendency of intensity and *** change tendency may be related to the occurrence of earthquake *** of the underlying intensity trend plays an important role in the analysis of data and disaster *** chaos theory and the radial basis function neural network,this paper proposes a forecasting model of the chaotic radial basis function neural network to conduct underlying intensity trend forecasting by the Earth’s natural pulse electromagnetic field *** main strategy of this forecasting model is to obtain parameters as the basis for optimizing the radial basis function neural network and to forecast the reconstructed Earth’s natural pulse electromagnetic field *** verification experiments,we employ the 3 and 6 days’data of two channels as training samples to forecast the 14 and 21-day Earth’s natural pulse electromagnetic field data *** to the forecasting results and absolute error results,the chaotic radial basis function forecasting model can fit the fluctuation trend of the actual signal strength,effectively reduce the forecasting error compared with the traditional radial basis function ***,this network may be useful for studying the characteristics of the Earth’s natural pulse electromagnetic field signal before a strong earthquake and we hope it can contribute to the electromagnetic anomaly monitoring before the earthquake.

关键词： Earth’s natural pulse electromagnetic field Chaos theory Radial Basis Function neural network Forecasting model

A neural network to predict reactor core behaviors

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Nuclear Science and Techniques 2014年第1期25卷 75-80页

作者： juan Jose Ortiz-Servin david A.Pelta Jose Alejro Castillo Instituto Nacional de Investigaciones Nucleares Carretera Mexico Toluca S/NLa Marquesa OcoyoacacEstado de Mexico ETS Ingenieria Informatica y Telecomunicaciones Universidad de GranadaC/Daniel Saucedo Aranda

The global fuel management problem in BWRs(Boiling Water Reactors) can be understood as a very complex optimization problem,where the variables represent design decisions and the quality assessment of each solution is done through a complex and computational expensive *** last aspect is the major impediment to perform an extensive exploration of the design space,mainly due to the time lost evaluating non promising *** this work,we show how we can train a Multi-Layer Perceptron(MLP) to predict the reactor behavior for a given *** trained MLP is able to evaluate the configurations immediately,thus allowing performing an exhaustive evaluation of the possible configurations derived from a stock of fuel lattices,fuel reload patterns and control rods *** our particular problem,the number of configurations is approximately 7.7×10^(10);the evaluation with the core simulator would need above 200 years,while only 100hours were required with our approach to discern between bad and good *** later were then evaluated by the simulator and we confirm the MLP *** good core configurations reached the energy requirements,satisfied the safety parameter constrains and they could reduce uranium enrichment costs.

关键词：神经网络预测行为质量评估堆芯沸水反应堆多层感知器 MLP 优化问题

Dendritic nanoarchitecture imparts ZSM-5 zeolite with enhanced adsorption and catalytic performance in energy applications

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Journal of Energy Chemistry 2023年第5期80卷 77-88,I0003页

作者： María del Mar Alonso-Doncel Cristina Ochoa-Hernández gema gómez-Pozuelo Adriana Oliveira Joségonzález-Aguilar ángel Peral Raúl Sanz david P.Serrano Thermochemical Processes Unit IMDEA Energy InstituteAvda.Ramon de la Sagra3E28935MostolesMadridSpain Department of Heterogeneous Catalysis Max-Planck-Institut für KohlenforschungKaiser-Wilhem-Platz14540Muheim an der RuhGermay Department of Chemical and Environmental Technology Rey Juan Carlos UniversityC/Tulipan s/nE28933MostolesMadridSpain High Temperature Processes Unit IMDEA Energy InstituteAvda.Ramon de la Sagra3E28935MostolesMadridSpain Department of Chemical Energy and Mechanical TechnologyRey Juan Carlos UniversityC/Tulipan s/n28933MostolesMadridSpain

The development of zeolites possessing dendritic features represents a great opportunity for the design of novel materials with applications in a large variety of fields and,in particular,in the energy sector to afford its transition towards a low carbon *** the current work,ZSM-5 zeolite showing a dendritic3D nanoarchitecture has been synthesized by the functionalization of protozeolitic nanounits with an amphiphilic organosilane,which provokes the branched aggregative growth of zeolite *** ZSM-5 exhibits outstanding accessibility arising from a highly interconnected network of radially-oriented mesopores(3-10 nm)and large cavities(20-80 nm),which add to the zeolitic micropores,thus showing a well-defined trimodal pore size *** singular features provide dendritic ZSM-5 with sharply enhanced performance in comparison with nano-and hierarchical reference materials when tested in a number of energy related applications,such as VOCs(toluene)adsorption(improved capacity),plastics(low-density polyethylene)catalytic cracking(boosted activity)and hydrogen production by methane catalytic decomposition(higher activity and deactivation resistance).

关键词： Dendritic ZSM-5 VOCs adsorption Plastics cracking Methane decomposition Hydrogen production

SHRIMP zircon U-Pb ages from coal beds across the Permian-Triassic boundary, eastern Yunnan, southwestern China

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Journal of Palaeogeography 2018年第2期7卷 117-129页

作者： juan Wang Long-Yi Shao Hao Wang Baruch Spiro david Large State Key Laboratory of Coal Resources and Safety Mining College of Geoscience and Surveying Engineering China University of Mining and Technology (Beijing) School of Resources and Environment Henan Polytechnic University Department of Mineralogy The Natural History MuseumLondon Faculty of Engineering University of Nottingham

The first SHRIMP zircon U e Pb ages from coal beds close to the end-Permian mass extinction are reported from the Ccoal seam in the Yantang Mine in Laibin Town, Xuanwei County, eastern Yunnan *** were extracted from kaolinite claystone layers, defined as tonsteins(volcanic ash deposits), in the subseam Band Bof the coal seam *** U-Pb ages are 252.0 ± 2.3 Ma and 250.3 ± 2.1 Ma for the sub-seam Band B, respectively. Within analytical uncertainties, these U-Pb ages include the time period of the onset of the mass extinction at 251.941 ± 0.037 Ma, which was obtained from the marine Meishan section in Zhejiang Province, ~1600 km away from the Yantang Mine. These new ages represent not only the first and closest ages to the PTB mass extinction in terrestrial coal beds, but also ages from the nearest site to the Emeishan volcanoes investigated so far. Therefore these new data provide the most accurate stratigraphic horizon of terrestrial facies of the end-Permian extinction in South China. The Emeishan volcanoes were likely the source of volcanic ash in the coal seams at the Xuanwei County and broader areas in South China. Furthermore, the minerals and geochemistry characteristics of the Ccoal seam also implied the influences of contemporaneous volcanic activities.

关键词： PTB mass extinction C1 coal seam SHRIMP U-Pb isotope age Xuanwei County Yunnan Province

A Non-Destructive Time Series Model for the Estimation of Cherry Coffee Production

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Computers, Materials & Continua 2022年第3期70卷 4725-4743页

作者： Jhonn Pablo Rodríguez david griol Zoraida Callejas juan Carlos Corrales Telematics Engineering group University of CaucaPopayán190002Colombia INRAE University of ToulouseUMR 1248 AGIRF-31326Castanet TolosanFrance Department of Software Engineering University of GranadaGranada18071Spain

Coffee plays a key role in the generation of rural employment in *** than 785,000 workers are directly employed in this activity,which represents the 26%of all jobs in the agricultural *** coffee growers estimate the production of cherry coffee with the main aim of planning the required activities,and resources(number of workers,required infrastructures),anticipating negotiations,estimating,price,and foreseeing losses of coffee production in a specific *** important processes can be affected by several factors that are not easy to predict(e.g.,weather variability,diseases,or plagues.).In this paper,we propose a non-destructive time series model,based on weather and crop management information,that estimate coffee production allowing coffee growers to improve their management of agricultural activities such as flowering calendars,harvesting seasons,definition of irrigation methods,nutrition calendars,and programming the times of concentration of production to define the amount of personnel needed for *** combination of time series and machine learning algorithms based on regression trees(XgBOOST,TR and RF)provides very positive results for the test dataset collected in real conditions for more than a *** best results were obtained by the XgBOOST model(MAE=0.03;RMSE=0.01),and a difference of approximately 0.57%absolute to the main harvest of 2018.

关键词： Cherry coffee production estimation learner approaches time series weather data crop management data

Bigger or long-winged male common crossbills exhibit redder carotenoid-based plumage coloration

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Current Zoology 2023年第2期69卷 165-172页

作者： Blanca Fernandez-Eslava Daniel Alonso david galicia juan Arizaga Carlos Alonso-Alvarez Biologia Ambiental Universidad de NavarraFacultad de CienciasC/Irunlarrea1 Pamplona31008 NavarraSpain Ornitologia Sociedad de Ciencias de AranzadiZorroagagaina 1120014 DonostiaSan SebastianSpain Ecologia Evolutiva Museo Nacional de Ciencias Naturales(CSiC)Edificio Pinar 2528006 MadridSpain

Carotenoid-based ornaments are often considered reliable(honest)individual condition signals because their expression implies physiological costs unaffordable for low-quality animals(handicap signals).Recently,it has been suggested that efficient cell respiration is mandatory for producing red ketocarotenoids from dietary yellow *** implies that red colorations should be entirely unfalsifiable and independent of expression costs(index signals).In a precedent study,male common crossbills,Loxia curvirostra,showing a red plumage reported higher apparent survival than those showing yellowish-orange *** plumage redness in this species is due to ketocarotenoid accumulation in ***,we correlated the male plumage redness(a 4-level visual score:yellow,patchy,orange,and red)and the body morphology in more than 1,ooo adult crossbills captured in 3 Iberian localities to infer the mechanisms responsible for color evolution.A principal component analysis summarized morphometry of 10 variables(beak,wing,tarsus length,etc.).The overall body size(PC1)and the length of flight feathers regarding body size(Pc3)showed significant positive relationships with plumage *** redness was barely correlated with bill shape measures,suggesting no constraint in acquiring carotenoids from pine ***,large body sizes or proportionally long flying feathers could help carotenoid acquisition via social competition or increased foraging *** longer flight feathers might also be associated with a specific cell respiration profile that would simultaneously favor flying capacities and enzymatic transformations needed for ketocarotenoid *** a phenotypic profile would agree with the hypothesis of ketocarotenoid-based colors acting as individual quality index signals.

关键词： avian carotenoids color and biometrics Loxia genus Mediterranean crossbills resource allocation trade-offs shared pathway hypothesis