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Friction 2024年第10期12卷 2325-2343页

作者： Cristina GARCÍA-CABEZÓn Juan Alfonso nARAnJO Celia GARCÍA-HERnÁndeZ Cristina BERGes Gemma HERRAnZ Fernando martÍn-PEDROSA Materials Engineering E.I.I.Universidad de ValladolidValladolid 47011Spain InEI-escuela Técnica Superior de Ingeniería Industrial(ETSII) Universidad de Castilla La ManchaCastilla-La Mancha 13071Spain

Fused filament fabrication(FFF)is one of the additive manufacturing processes which has gained more interest because of its simplicity and *** technology is similar to the conventional metal injection moulding(MIM)process,consisting of the feedstock preparation of metal powder and polymer binders,followed by layer-by-layer 3D printing(FFF)or injection(MIM)to create green parts and,finally,debinding and ***,both technologies provide near-dense *** work presents an in-depth study of the processing method’s *** porosity,microstructure,hardness,corrosion,and tribocorrosion behaviour are compared for 17-4 PH SS samples processed from powder by additive manufacturing using FFF and MIM,as well as conventional powder metallurgy(PM)*** samples exhibited the highest macro and microhardness,while corrosion behaviour was similar for both MIM and FFF samples,but superior in comparison to conventional PM ***,the FFF-as fabricated samples displayed a significant improvement in tribocorrosion resistance that could be explained by the higher proportion of delta ferrite and retained austenite in their microstructure.

关键词： 17-4 PH SS fused filament fabrication(FFF) metal injection moulding(MIM) corrosion behaviour powder metallurgy(PM) tribocorrosion behaviour

Output feedback adaptive super twisting sliding mode control for quadrotor UAVs

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Control Theory and Technology 2024年第1期22卷 92-105页

作者： Oscar Salas-Peña Jesus deLeón-Morales Susana V.Gutiérrez-martínez École Centrale de nantes-LS2n UMR 6004 CNRS44300NantesFrance Facultad de Ingeniería Mecánica y Eléctrica Universidad Autónoma de Nuevo León66451San Nicolás de Los GarzaMexico

In this paper, a sliding mode control with adaptive gain combined with a high-order sliding mode observer to solve the tracking problem for a quadrotor UAV is addressed, in presence of bounded external disturbances and parametric uncertainties. The high order sliding mode observer is designed for estimating the linear and angular speed in order to implement the proposed scheme. Furthermore, a Lyapunov function is introduced to design the controller with the adaptation law, whereas an analysis of finite time convergence towards to zero is provided, where sufficient conditions are obtained. Regarding previous works from literature, one important advantage of proposed strategy is that the gains of control are parameterized in terms of only one adaptive parameter, which reduces the control effort by avoiding gain overestimation. numerical simulations for tracking control of the quadrotor are given to show the performance of proposed adaptive control–observer scheme.

关键词： Adaptive super twisting controller High-order sliding modes observer UAV

Europium recovery process by means of polymeric nanoparticles functionalized with acrylic acid,curcumin and fumaramide

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Journal of Rare Earths 2024年第10期42卷 1950-1959页

作者： P.A.martínez-Montoya J.M.del Río A.de J.Morales-Ramirez M.Corea escuela Superior de Ingeniería Química e Industrias Extractivas ESIQIE-IPNDepartamento de Ingeniería Metalúrgica UPALM S/N Col.Lindavista escuela Superior de Ingenieria Química e Industrias Extractivas ESIQIE-IPNLaboratorio de Investigación en Polímeros y NanomaterialesUPALM S/N Col.Lindavista Centra de Investigación e Innovación Tecnológica CIITEC-IPNCda.de CECATIs/n

Polymeric nanoparticles of poly(methyl methacrylate) were obtained by emulsion polymerization techniques in a proce ss of two *** particles were functionalized with acrylic acid,curcumin,and fumaramide and three series of polymeric particles were *** incorporation of functional groups was confirmed by Fourier transform-infrared spectrosocopy(FT-IR) and ultraviolet-visible(UV-Vis) *** spherical morphology of particles with an average diameter of 100 nm was observed by scartning electron microscopy(SEM).The polymeric materials were used for recovery of [Eu]from synthetic *** nanoparticles show excellent chelation capacity to trap rare-earth ions,because they recover more than 85% of [Eu] at pH of *** images of SEM after extraction process show arrays between particles with larger average particle sizes to 1.5 *** addition,the particles have a good stripping capacity,exceeding 50% of it,maintaining their homogeneity in morphology and good stability in dispersion for the recovery and stripping processes.A pseudo-second model order is obtained for the extraction and stripping processes while the best results of stripping process are obtained at pH of6.

关键词： Chelating effect Emulsion polymerization Extraction process Rare earths Stripping process [Eu]recovery

Improving the radiological diagnosis of hepatic artery thrombosis after liver transplantation: Current approaches and future challenges

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World Journal of Transplantation 2024年第1期14卷 1-8页

作者： Cristian Lindner Raúl Riquelme Rodrigo San martín Frank Quezada Jorge Valenzuela Juan P Maureira martín Einersen department of Radiology Faculty of MedicineUniversity of ConcepciónConcepción 4030000Chile department of Radiology Hospital Clínico Regional Guillermo Grant BenaventeConcepción 4030000Chile department of Statistics Catholic University of MauleTalca 3460000Chile neurovascular Unit Department of RadiologyHospital Clínico Regional Guillermo Grant BenaventeConcepción 4030000Chile

Hepatic artery thrombosis(HAT)is a devastating vascular complication following liver transplantation,requiring prompt diagnosis and rapid revascularization treatment to prevent graft *** present,imaging modalities such as ultrasound,computed tomography,and magnetic resonance play crucial roles in diagnosing *** imaging techniques have improved sensitivity and specificity for HAT diagnosis,they have limitations that hinder the timely diagnosis of this *** this sense,the emergence of artificial intelligence(AI)presents a transformative opportunity to address these diagnostic *** development of machine learning algorithms and deep neural networks has demonstrated the potential to enhance the precision diagnosis of liver transplant complications,enabling quicker and more accurate detection of *** article examines the current landscape of imaging diagnostic techniques for HAT and explores the emerging role of AI in addressing future challenges in the diagnosis of HAT after liver transplant.

关键词： Liver transplantation Postoperative complications Hepatic artery Thrombosis Radiology Artificial intelligence

Enhancing Hyper-Spectral Image Classification with Reinforcement Learning and Advanced Multi-Objective Binary Grey Wolf Optimization

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Computers, Materials & Continua 2024年第6期79卷 3469-3493页

作者： Mehrdad Shoeibi Mohammad Mehdi Sharifi nevisi Reza Salehi Diego martín Zahra Halimi Sahba Baniasadi TheWPI Business School Worcester Polytechnic InstituteWorcesterMassachusetts01609-2280USA department of Industrial Engineering Iran University of Science and TechnologyNarmakTehran16846-13114Iran ETSI de Telecomunicación Universidad Politécnica de MadridAv.Complutense 30Madrid28040Spain department of Civil and Environmental Engineering University of MarylandCollege ParkMaryland20742USA department of Industrial Engineering College of EngineeringUniversity of HoustonHoustonTexas77204USA

Hyperspectral(HS)image classification plays a crucial role in numerous areas including remote sensing(RS),agriculture,and the monitoring of the *** band selection in HS images is crucial for improving the efficiency and accuracy of image *** process involves selecting the most informative spectral bands,which leads to a reduction in data *** on these key bands also enhances the accuracy of classification algorithms,as redundant or irrelevant bands,which can introduce noise and lower model performance,are *** this paper,we propose an approach for HS image classification using deep Q learning(DQL)and a novel multi-objective binary grey wolf optimizer(MOBGWO).We investigate the MOBGWO for optimal band selection to further enhance the accuracy of HS image *** the suggested MOBGWO,a new sigmoid function is introduced as a transfer function to modify the wolves’*** primary objective of this classification is to reduce the number of bands while maximizing classification *** evaluate the effectiveness of our approach,we conducted experiments on publicly available HS image datasets,including Pavia University,Washington Mall,and Indian Pines *** compared the performance of our proposed method with several state-of-the-art deep learning(DL)and machine learning(ML)algorithms,including long short-term memory(LSTM),deep neural network(Dnn),recurrent neural network(Rnn),support vector machine(SVM),and random forest(RF).Our experimental results demonstrate that the Hybrid MOBGWO-DQL significantly improves classification accuracy compared to traditional optimization and DL ***-DQL shows greater accuracy in classifying most categories in both datasets *** the Indian Pine dataset,the MOBGWO-DQL architecture achieved a kappa coefficient(KC)of 97.68%and an overall accuracy(OA)of 94.32%.This was accompanied by the lowest root mean square error(RMSE)of 0.94,indicating very precise

关键词： Hyperspectral image classification reinforcement learning multi-objective binary grey wolf optimizer band selection

Secrecy Outage Probability Minimization in Wireless-Powered Communications Using an Improved Biogeography-Based Optimization-Inspired Recurrent neural network

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Computers, Materials & Continua 2024年第3期78卷 3971-3991页

作者： Mohammad Mehdi Sharifi nevisi Elnaz Bashir Diego martín Seyedkian Rezvanjou Farzaneh Shoushtari Ehsan Ghafourian department of Industrial Engineering Iran University of Science and TechnologyNarmakTehran16846-13114Iran department of Computer Science Iowa State UniversityAmesIowaIA50011USA ETSI de Telecomunicación Universidad Politécnica de MadridMadrid28040Spain department of Engineering California State University East BayHaywardCalifornia94542USA department of Industrial Engineering Bu-Ali Sina UniversityHamedan65178-38695Iran

This paper focuses on wireless-powered communication systems,which are increasingly relevant in the Internet of Things(IoT)due to their ability to extend the operational lifetime of devices with limited *** main contribution of the paper is a novel approach to minimize the secrecy outage probability(SOP)in these *** SOP is crucial for maintaining the confidentiality and integrity of data,especially in situations where the transmission of sensitive data is *** proposed method harnesses the power of an improved biogeography-based optimization(IBBO)to effectively train a recurrent neural network(Rnn).The proposed IBBO introduces an innovative migration *** core advantage of IBBO lies in its adeptness at maintaining equilibrium between exploration and *** is accomplished by integrating tactics such as advancing towards a random habitat,adopting the crossover operator from genetic algorithms(GA),and utilizing the global best(Gbest)operator from particle swarm optimization(PSO)into the IBBO *** IBBO demonstrates its efficacy by enabling the Rnn to optimize the system parameters,resulting in significant outage probability *** comprehensive simulations,we showcase the superiority of the IBBO-Rnn over existing approaches,highlighting its capability to achieve remarkable gains in SOP *** paper compares nine methods for predicting outage probability in wireless-powered *** IBBO-Rnn achieved the highest accuracy rate of 98.92%,showing a significant performance *** contrast,the standard Rnn recorded lower accuracy rates of 91.27%.The IBBO-Rnn maintains lower SOP values across the entire signal-to-noise ratio(SnR)spectrum tested,suggesting that the method is highly effective at optimizing system parameters for improved secrecy even at lower SnRs.

关键词： Wireless-powered communications secrecy outage probability improved biogeography-based optimization recurrent neural network

High-repetition-rate source of nanosecond duration kA-current pulses driven by relativistic laser pulses

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High Power Laser Science and Engineering 2024年第3期12卷 106-115页

作者： Michael Ehret Jakub Cikhardt Philip Wykeham Bradford Iuliana-Mariana Vladisavlevici Tomas Burian Diego de Luis Jose Luis Henares Rubén Hernández martín Jon Imanol Apiñaniz Roberto Lera JoséAntonio Pérez-Hernández João Jorge Santos Giancarlo Gatti Centro de Láseres Pulsados(CLPU) VillamayorSpain Czech Technical University in Prague Faculty of Electrical EngineeringPragueCzech Republic Univ.Bordeaux-CnRS-CEA Centre Lasers Intenses et Applications(CELIA)UMR 5107TalenceFrance department of Radiation and Chemical Physics FZU-Institute of Physics of the Czech Academy of SciencesPragueCzech Republic

We report the first high-repetition-rate generation and simultaneous characterization of nanosecond-scale return currents of kA-magnitude issued by the polarization of a target irradiated with a PW-class high-repetition-rate titanium:sapphire laser system at relativistic *** present experimental results obtained with the VEGA-3 laser at intensities from5×10^(18)to 1.3×10^(20)W cm^(-2).A non-invasive inductive return-current monitor is adopted to measure the derivative of return currents of the order of kA ns-1and analysis methodology is developed to derive return *** compare the current for copper,aluminium and Kapton targets at different laser *** data show the stable production of current peaks and clear prospects for the tailoring of the pulse shape,which is promising for future applications in highenergy-density science,for example,electromagnetic interference stress tests,high-voltage pulse response measurements and charged particle beam *** compare the target discharge of the order of hundreds of nC with theoretical predictions and a good agreement is found.

关键词： current pulses electromagnetic pulse application high-power laser relativistic laser plasma

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Wear protection assessment of ultralow viscosity lubricants in high-power-density engines:A novel wear prediction algorithm

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Friction 2024年第8期12卷 1785-1800页

作者： Javier BLAnCO-RODRÍGUEZ Jacobo PORTEIRO JoséA.LÓPEZ-CAMPOS martíCORTADA-GARCÍA Silvia FERnÁndeZ-CASTEJÓn CInTECX Universidade de VigoLagoas-Marcosende s/nVigo 36310Spain Repsol SA MadridSpain

Durability and reliability have been studied for decades through intensive trial-error ***,there are numerous fields of application where the costs associated with this approach are not *** lubricated machines with severe dynamic loads,such as high-power-density engines,simulation tools offer clear advantages over intensive *** and multiple scenarios can be cost-effectively simulated to assess different lubricants and engine *** work presented here details the study of wear based on a validated elastohydrodynamic(EHD)simulation model of the connecting rod journal *** model accounts for elastic deformation through a connecting rod finite element model(FEM).In addition,multiple lubricant rheological and tribological dependences,determined by specific experimental tests,are applied in the model through their interaction with the simulation ***,a novel wear algorithm is proposed to predict wear depth over time evolution along a proposed wear cycle based on the typical working ranges of high-performance engines.A final assessment is presented to compare 4 different ultralow-viscosity lubricants in their protective performance under severe *** results show the evolution of the wear load and wear depth over the wear *** evaluation is key to describing a lubricant selection procedure for high-power-density engines.

关键词： wear modelling finite element modelling mixed lubrication elastohydrodynamic(EHD) internal combustion engines bearings

Long-term monitoring reveals the effect of precipitation and silviculture on nothofagus regeneration in northern Patagonia mixed forests

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Ecological Processes 2024年第2期13卷 103-117页

作者： Georgina Sola Camila Mateo Alejandro dezzotti Paula Marchelli Hernán Attis Beltrán Renato Sbrancia Luis Chauchard Marcelo González Pe?alba martín Lara Verónica El Mujtar Consejo nacional de Investigaciones Científicas y Técnicas (COnICET ) Asentamiento Universitario San martín de los Andes (AUSMA-UnCo) Instituto de Investigaciones Forestales y Agropecuarias Bariloche (IFAB) Instituto Nacional de Tecnología Agropecuaria (INTA) Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET ) departamento de Conservación y Manejo Parque Nacional Lanín- Administración de Parques Nacionales (PNL-APN)

Background Tree regeneration is a key component of resilience because it promotes post-disturbance recovery of forests. northwestern Patagonia from Argentina is occupied by nothofagus alpina（na）, n. obliqua（no）, and n. dombeyi（nd） forests that grow along an intense precipitation gradient, managed throughout shelterwood silvicultural system by technicians of the Lanin natural Reserve. The objective of this study was to evaluate the influence of seeding cuttings over the dynamics of nothofagus mixed forests across landscape（precipitation gradient） based mainly on the composition and abundance of tree regeneration, permanent sampling plots and generalized linear mixed models. In particular, we analysed:（i） the structure of sexual and asexual regeneration during nd > 20 years after harvest（the dynamics of managed forests）, and（ii） the structure of sexual regeneration in primary and managed forests after > 20 years of harvest（the effect of silviculture）.Results nd was the most abundant species in the regeneration of managed forests during all periods in both sites despite its lower contribution to the adult cohort. During the 10–20 years period after harvest, the humid site exhibited higher regeneration density than the mesic site(120,000 and 6000 ind ha-1, respectively), and it decreased afterwards. The number of established regeneration（> 2 m height） was lower for na in the mesic site and for no in the humid site(0 and 57 ind ha-1, respectively). However, in comparison to no, na showed a higher number of sprouted stumps and sprouts per stump, and a higher sprout height in the mesic site. no exhibited higher sprout mortality in the humid site. Finally, the regeneration of primary forests showed lower density and height, and a more balanced composition than that of managed *** The silvicultural effects on the mixed forest regeneration dynamics was strongly influenced by the condition of sites. Therefore, management prescriptions should be adj

关键词： nothofagus alpina nothofagus obliqua nothofagus dombeyi Basal sprouting Shelterwood silvicultural system Ecological resilience

Wood anatomical acclimation in the endemic genus Polylepis in Peruvian Andean forests

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Journal of Mountain Science 2024年第9期21卷 2986-3000页

作者： Anthony GUERRA Fressia n.AMes-martÍnEZ Ernesto C.RODRÍGUEZ-RAMÍREZ Postgraduate Programme in Agronomy/Plant Physiology department of Biology-Institute of natural Sciences Federal University of LavrasLavras 37203-202Minas Gerais 30000-31999Brazil Laboratory of Biotechnology and Molecular Biology Continental UniversitySan Antonio UrbanizationHuancayo 12000Peru Ecology and Biodiversity Research Programme ANDINUS AssociationMiguel Grau Street 370Huancayo 12000Peru dendrochronology Laboratory Continental UniversitySan Carlos Avenue 1980Huancayo 12000Peru

Polylepis(Queñua)is a dominant woody plant genus in Andean Puna forests that occurs in a wide range of montane habitats and is ecologically diverse in endemism,which may be particularly threatened by climate *** anatomical traits are essential for understanding how plants adjust their ecophysiological requirements and maximize their resilience,resistance,and recovery to extreme *** the effects of extreme climatic conditions in high altitude ecosystems have been studied extensively,our knowledge is relatively limited to quantitative differences in the main xylem *** address this gap,we assessed the acclimation of wood anatomical traits in six Peruvian Andean Polylepis species with different water availability(semi-dry with high moisture and semiarid with dry winters).We selected hydraulic diameter,vessel density,vessel grouping index,solitary vessel index,vulnerability index,mesomorphy index,vessel element length,fiber length,fiber wall thickness,fiber lumen diameter,and total fiber diameter that can provide relevant eco-wood anatomical acclimation to hydric *** performed multivariate analysis to determine the leading dimensions of covariation among Polylepis species and climatic *** wood anatomical traits(vessel grouping index,vulnerability index,and fiber wall thickness)were dissimilar between xeric-and mesic-Polyelpis *** study demonstrates that wood anatomical traits in Peruvian Andean Polylepis species provides high-resolution and long-term eco-wood anatomical signals on how climate oscillations drive the acclimation processes of fiber and vessel *** findings underscore the significance of xylem hydraulic adjustment to various hydrological environments in Andean puna *** evaluating the effects of drought on wood anatomical characteristics and ecological function,we demonstrate the capacity of tree species to adapt and endure climate-related changes,thereby emphasizing their resilience and ada

关键词： Carlquist indices Climatic resilience Vessel traits Fiber Functional trait Hydric stress

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