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The ρ-variation of the Hermitian Riesz Transform

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Acta Mathematica Sinica,English Series 2010年第10期26卷 1827-1838页

作者： Raquel CRESCIMBENI Francisco Javier MARTíN-REYES Alberto DE lA TORRE josé l.torrea Departamento de Matemática Universidad Nacional del Comahue Facultad de Economía y Administración Departamento de Análisis Matemático Facultad de Ciencias Universidad de Málaga Facultad de Ciencias Universidad Autónoma de Madrid ICMAT-CSIC-UAM-UCM-UC3M

In this paper we prove the behaviour in weighted lp spaces of the oscillation and variation of the Hilbert transform and the Riesz transform associated with the Hermite operator of dimension 1. We prove that this operator maps lP（R, w（x）dx） into itself when w is a weight in the Ap class for 1 〈 p 〈 ∞. For p = 1 we get weak type for the A1 class. Weighted estimated are also obtained in the extreme case p = ∞.

关键词： Oscillation-p-variation-singular integral-Hermite operator

Fractional Square Functions and Potential Spaces, Ⅱ

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Acta Mathematica Sinica,English Series 2015年第11期31卷 1759-1774页

作者： Jorge J.BETANCOR Juan C.FARIA lourdes RODRIGUEZ-MESA Ricardo TESTONI jos l.torrea Departamento de Anlisis Matemtico Universidad de La Laguna Campus de Anchieta Avda.Astrofísico Francisco Snchez 38271 La Laguna (Sta.Cruz de Tenerife) Spain Departamento de Matemtica Universidad Nacional del Sur Avda. Alem 1253 8000 Bahía BlancaBuenos Aires Argentina Departamento de Matem'aticas Universidad Autónoma de Madrid ICMAT-CSIC-UAM-UCM-UC3MCiudad Universitaria de Canto Blanco 28049 Madrid Spain

In this paper, we study fractional square functions associated with the Poisson semigroup for SchrSdinger operators. We characterize the potential spaces in the SchrSdinger setting by using vertical, area and gλ, fra... 详细信息

关键词： g-function Schrodinger operator potential space

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

Fast synthesis of gold nanoparticles by cold atmospheric pressure plasma jet in the presence of Au^(+) ions and a capping agent

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Plasma Science and Technology 2024年第7期26卷 108-115页

作者： Tatiana HABIB josé Mauricio A.CAIUT Bruno CAIllIER laboratoire Diagnostics des Plasmas Hors Equilibre(DPHE) Universitéde ToulouseINU ChampollionAlbi 81000France Department of Chemistry The Nanomaterials and Luminescent Systems GroupFaculty of PhilosophyScience and Letters at Ribeirão PretoUniversity of São PauloRibeirão Preto-SP 14040-901Brazil

Homogeneous gold nanoparticles were synthesized under atmospheric pressure using a nonthermal helium plasma jet in a single-step process.A current power supply was used to generate the plasma discharge rich in diverse reactive *** species induce rapid chemical reactions responsible for the reduction of the gold salts upon contact with the liquid *** this study,spherical and monodispersed gold nanoparticles were obtained within 5 min of plasma exposure using a solution containing gold(Ⅲ)chloride hydrate(HAuCl_(4))as a precursor and polyvinylpyrrolidone(PVP)as a capping agent to inhibit *** formation of these metal nanoparticles was initially perceptible through a visible change in the sample's color,transitioning from light yellow to a red/pink *** was subsequently corroborated by UVvis spectroscopy,which revealed an optical absorption in the 520-550 nm range for Au NPs,corresponding to the surface plasmon resonance(SPR)*** investigation into the impact of various parameters,including plasma discharge duration,precursor and capping agent concentrations,was carried out to optimize conditions for the formation of well-separated,spherical gold *** light scattering(DlS)was used to measure the size of these nanoparticles,transmission electron microscopy(TEM)was used to observe their morphology and X-ray diffraction(XRD)was also employed to determine their crystallographic *** results confirm that homogeneous spherical gold nanoparticles with an average diameter of 13 nm can be easily synthesized through a rapid,straightforward,and environmentally friendly approach utilizing a helium atmospheric pressure plasma.

关键词： gold nanoparticles non-thermal plasma jet helium DBD

Enhancement of the CO_(2)adsorption and hydrogenation to CH_(4)capacity of Ru–Na–Ca/γ–Al_(2)O_(3)dual function material by controlling the Ru calcination atmosphere

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Journal of Environmental Sciences 2024年第6期140卷 292-305页

作者： Alejandro Bermejo-lópez Beñat Pereda-Ayo Jon A.Onrubia-Calvo joséA.González-Marcos Juan R.González-Velasco Department of Chemical Engineering Faculty of Science and TechnologyUniversidad del País Vasco UPV/EHUBarrio Sarrienas/n48940 LeioaBizkaiaSpain

Integrated CO_(2)capture and utilization(ICCU)technology requires dual functional materials(DFMs)to carry out the process in a single reaction *** influence of the calcination atmosphere on efficiency of 4%Ru-8%Na_(2)CO_(3)-8%CaO/γ-Al_(2)O_(3)DFM is *** adsorbent precursors are first co-impregnated onto alumina and calcined in ***,Ru precursor is impregnated and four aliquotes are subjected to different calcination protocols:static air in muffle or under different mixtures(10%H_(2)/N_(2),50%H_(2)/N_(2)and N_(2))*** are characterized by XRD,N_(2)adsorption-desorption,H_(2)chemisorption,TEM,XPS,H_(2)-TPD,H_(2)-TPR,CO_(2)-TPD and *** catalytic behavior is evaluated,in cycles of CO_(2)adsorption and hydrogenation to CH_(4),and temporal evolution of reactants and products concentrations is *** calcination atmosphere influences the physicochemical properties and,ultimately,activity of *** data and catalytic performance discover the acccomodation of Ru nanoparticles disposition and basic sites is mostly influencing the catalytic *** calcined under N_(2)flow(RuNaCa-N_(2))shows the highest CH_(4)production(449μmol/g at 370℃),because a well-controlled decomposition of precursors which favors the better accomodation of adsorbent and Ru phases,maximizing the specific surface area,the Ru-basic sites interface and the participation of different basic sites in the CO_(2)methanation ***,the calcination in a N_(2)flow is revealed as the optimal calcination protocol to achieve highly efficient DFM for integrated CO_(2)adsorption and hydrogenation applications.

关键词： CO_(2)methanation Integrated CO_(2)capture and utilization(ICCU) Dual functional material(DFM) Ru calcination atmosphere

Chi-square automatic interaction detection(CHAID)analysis of the use of safety goggles and face masks as personal protective equipment(PPE)to protect against occupational biohazards

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Journal of Biosafety and Biosecurity

Journal of Biosafety and Biosecurity 2024年第2期6卷 125-133页

作者： Raúl Aguilar-Elena Juán joséAgún-González Universidad Internacional de Valencia ValenciaSpain

Background:This study represents the first Spanish investigation to rigorously evaluate compliance with the use of safety goggles and face masks as essential personal protective equipment(PPE)in companies with workplaces involving exposure to biological ***:This study aimed to examine the degree of use of face masks and safety goggles as personal protective equipment(PPE),the factors that influence their use,and the profile of workers exposed to occupational biological agents in Spanish companies in the health sector,farming sector,meat industry,waste treatment plants,food industry,and veterinary ***:We conducted a cross-sectional descriptive study involving 590 Spanish workers from 51 *** developed a 34-item questionnaire to assess workers’perception of risk related to exposure to biological agents in their *** the questions,three were designed to measure the degree of use of key protective equipment in sectors with biological agent exposure:protective gloves,safety goggles or face *** only analyzed safety goggles and face *** performed various statistical analyses,including Cronbach’s alpha,frequency of endorsement,content validity ratio using lawshe’s method,varimax rotation,the Kaiser-Meyer-Olkin test,and Bartlett’s sphericity test,to assess the internal consistency and reliability of the ***,we employed a chi-square automatic interaction detection(CHAID)segmentation analysis,using workers’responses regarding their attitudes toward safety goggles and face mask usage as PPE for protection against biological risks,with demographic variables as independent ***:In the current study,CHAID analysis revealed that workers exposed to group 2 biological agents used more safety goggles and face shields compared with workers exposed to other groups of biological ***,workers in laboratories and the food industry used face masks more than workers of other ***

关键词： PPE Safety googles and breath mask CHAID Biological Agents Occupational Biosafety

Nuclear phylogenomics of Asteraceae with increased sampling provides new insights into convergent morphological and molecular evolution

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Plant Communications 2024年第6期5卷 117-138页

作者： Guojin Zhang Junbo Yang Caifei Zhang Bohan Jiao josél.Panero Jie Cai Zhi-Rong Zhang lian-Ming Gao Tiangang Gao Hong Ma College of life Sciences Hunan Normal UniversityChangshaHunan 410081China Department of Biology the Huck Institute of the Life Sciencesthe Pennsylvania State UniversityState CollegePA 16801USA State Key laboratory of Plant Diversity and Specialty Crops Institute of BotanyChinese Academy of SciencesBeijing 100093China Germplasm Bank of Wild Species Kunming Institute of BotanyChinese Academy of SciencesKunmingYunnan 650201China Wuhan Botanical Garden and Sino-Africa Joint Research Center Chinese Academy of SciencesWuhan 430074China Department of Integrative Biology University of TexasAustinTX 78712USA CAS Key laboratory for Plant Diversity and Biogeography of East Asia Kunming Institute of BotanyChinese Academy of SciencesKunmingYunnan 650201China lijiang National Forest Biodiversity National Observation and Research Station Kunming Institute of BotanyChinese Academy of SciencesLijiangYunnan 674100China

Convergent morphological evolution is widespread in flowering plants,and understanding this phenomenon relies on well-resolved *** phylogenetic reconstruction using transcriptome datasets has been successful in various angiosperm groups,but it is limited to taxa with available fresh ***,which are one of the two largest angiosperm families and are important for both ecosystems and human livelihood,show multiple examples of convergent *** Asteraceae phylogenies have resolved relationships among most subfamilies and many tribes,but many phylogenetic and evolutionary questions regarding subtribes and genera remain,owing to limited ***,we increased the sampling for Asteraceae phylogenetic reconstruction using transcriptomes and genome-skimming datasets and produced nuclear phylogenetic trees with 706 species representing two-thirds of recognized *** character reconstruction supports multiple convergent evolutionary events in Asteraceae,with gains and losses of bilateral floral symmetry correlated with diversification of some subfamilies and smaller groups,*** of the calyx-related pappus may have been especially important for the success of some subtribes and *** evolutionary analyses support the likely contribution of duplications of MADS-box and TCP floral regulatory genes to innovations in floral morphology,including capitulum inflorescences and bilaterally symmetric flowers,potentially promoting the diversification of *** divergences and reductions in CYC2 gene expression are related to the gain and loss of zygomorphic *** phylogenomic work with greater taxon sampling through inclusion of genome-skimming datasets reveals the feasibility of expanded evolutionary analyses using DNA samples for understanding convergent evolution.

关键词： sunflower family floral symmetry florets capitulescence molecular clock ancestral character pappus subtribe MADS-box TCP CYC2 gene family gene expression

Ferroelectricity Induced by Oxygen Vacancies in Rhombohedral ZrO_(2) Thin Films

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Energy & Environmental Materials 2024年第1期7卷 229-237页

作者： Veniero lenzi josé P.B.Silva Břetislav Šmíd Vladimir Matoín Cosmin M.Istrate Corneliu Ghica Judith l.MacManus-Driscoll luís Marques Physics Center of Minho and Porto Universities(CF-UM-UP) University of MinhoCampus de Gualtar 4710-057Braga Portugal laboratory of Physics for Materials and Emergent Technologies LapMETUniversity of Minho4710-057Braga Portugal Department of Surface and Plasma Science Faculty of Mathematics and PhysicsCharles UniversityV Holešovičkách 218000Prague 8 Czech Republic National Institute of Materials Physics 105 bis Atomistilor 077125Magurele Romania Department of Materials Science and Metallurgy 27 Charles Babbage Rd.Cambridge CB3 OFSUK

Rhombohedral phase Hf_(x)Zr_(1.x)O_(2)(HZO,x from 0 to 1)films are promising for achieving robust ferroelectric polarization without the need for an initial wake-up pre-cycling,as is normally the case for the more commonly studied orthorhombic ***,a large spontaneous polarization observed in rhombohedral films is not fully understood,and there are also large discrepancies between experimental and theoretical *** this work,in rhombohedral ZrO_(2)thin films,we show that oxygen vacancies are not only a key factor for stabilizing the phase,but they are also a source of ferroelectric polarization in the *** is shown experimentally through the investigation of the structural properties,chemical composition and the ferroelectric properties of the films before and after an annealing at moderate temperature(400℃)in an oxygen environment to reduce the V_(o)concentration *** experimental work is supported by density functional theory(DFT)calculations which show that the rhombohedral phase is the most stable one in highly oxygen defective ZrO_(2)*** DFT calculations also show that V_(o)contribute to the ferroelectric *** findings reveal the importance of V_(o)for stabilizing rhombohedral ZrO_(2)thin films with superior ferroelectric properties.

关键词： charged defects ferroelectric polarization rhombohedral phase stability zirconia

Electrifying Ba_(0.5)Sr_(0.5)Co_(0.8)Fe_(0.2)O_(3-δ) for focalized heating in oxygen transport membranes

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Journal of Energy Chemistry 2024年第4期91卷 99-110页

作者： Marwan laqdiem Julio García-Fayos laura Almar Alfonso J.Carrillo Álvaro Represa joséM.lópez Nieto Sonia Escolástico David Catalán-Martinez jose M.Serra Instituto de Tecnología Química(Universitat Politècnica de València–Consejo Superior de Investigaciones Científicas) Av.Los Naranjos s/nE-46022 ValenciaSpain

Industry decarbonization requires the development of highly efficient and flexible technologies relying on renewable energy resources,especially biomass and solar/wind *** the case of pure oxygen production,oxygen transport membranes(OTMs)appear as an alternative technology for the cryogenic distillation of air,the industrially-established process of producing ***,OTMs could provide oxygen from different sources(air,water,CO_(2),etc.),and they are more flexible in adapting to current processes,producing oxygen at 700^(-1)000℃.Furthermore,OTMs can be integrated into catalytic membrane reactors,providing new pathways for different *** first part of this study was focused on electrification on a traditional OTM material(Ba_(0.5)Sr_(0.5)Co_(0.8)Fe_(0.2)O_(3-δ)),imposing different electric currents/voltages along a capillary *** to the emerging Joule effect,the membrane-surface temperature and the associated O_(2) permeation flux could be ***,the OTM is electrically and locally heated and reaches 900℃on the surface,whereas the surrounding of the membrane was maintained at 650℃.The O_(2)permeation flux reached for the electrified membranes was~3.7 Nml min^(-1)cm^(-2),corresponding to the flux obtained with an OTM non-electrified at 900℃.The influence of depositing a porous Ce_(0.8)Tb_(0.2)O_(2-δ) catalytic/protective layer on the outer membrane surface revealed that lower surface temperatures(830℃)were detected at the same imposed electric ***,the electrification concept was demonstrated in a catalytic membrane reactor(CMR)where the oxidative dehydrogenation of ethane(ODHE)was carried *** reaction is very sensitive to temperature,and here,we demonstrate an improvement of the ethylene yield by reaching moderate temperatures in the reaction chamber while the O_(2) injection into the reaction can be easily fine-tuned.

关键词： Oxygen permeation Oxidative dehydrogenation of ethane Oxygen transport membranes Joule effect Mixed ionic-electronic conductors Catalytic membrane reactors