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Modelling dynamic pantograph loads with combined numerical analysis

railway Engineering Science 2024年第1期32卷 81-94页

作者： F.F.jackson r.Mishra j.M.rebelo j.Santos P.Antunes j.Pombo H.Magalhaes L.Wills M.Askill School of Computing and Engineering University of HuddersfieldHuddersfieldUK School of Computing and Engineering Institute of Railway ResearchUniversity of HuddersfieldHuddersfieldUK IDMEC Instituto Superior TecnicoUniversidade de LisboaLisbonPortugal ISEL Instituto Politecnico de LisboaLisbonPortugal Hitachi rail Newton AycliffeUK Wabtec/Brecknell Willis ChardUK

Appropriate interaction between pantograph and catenary is imperative for smooth operation of electric *** heights of overhead lines to accommodate level crossings,overbridges,and tunnels pose significant challenges in maintaining consistent current collection performance as the pantograph aerodynamic profile,and thus aerodynamic load changes significantly with operational *** research aims to analyse the global flow characteristics and aerodynamic forces acting on individual components of an HSX pantograph operating in different configurations and orientations,such that the results can be combined with multibody simulations to obtain accurate dynamic insight into contact ***,computational fluid dynamics simulations are used to investigate the pantograph component loads in a representative setting,such as that of the recessed cavity on a Class 800 *** an aerodynamic perspective,this study indicates that the total drag force acting on non-fixed components of the pantograph is larger for the knuckle-leading orientation rather than the knuckle-trailing,although the difference between the two is found to reduce with increasing pantograph *** the aerodynamic loads acting on individual components with multibody tools allows for realistic dynamic insight into the pantograph *** results obtained show how considering aerodynamic forces enhance the realism of the models,leading to behaviour of the pantograph-catenary contact forces closely matching that seen in experimental tests.

关键词： Pantograph-catenary interaction Pantograph aerodynamics Computational fluid dynamics Pantograph loads Current collection performance

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Multidimensional images and aberrations in STEM

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Chinese Physics B 2024年第9期33卷 68-74页

作者： Eric r.Hoglund Andrew r.Lupini Center for Nanophase Materials Sciences Oak Ridge National LaboratoryOak RidgeTN 37831United States

recent advances in scanning transmission electron microscopy(STEM)have led to increased development of multidimensional STEM imaging modalities and novel image reconstruction *** interest arises because the main electron lens in a modern transmission electron microscope usually has a diffraction-space information limit that is significantly better than the real-space resolution of the same *** state-of-affairs is sometimes shared by other scattering methods in modern physics and contributes to a broader excitement surrounding multidimensional techniques that scan a probe while recording diffraction-space images,such as ptychography and scanning nano-beam ***,the contrasting resolution in the two spaces raises the question as to what is limiting their effective ***,we examine this paradox by considering the effects of aberrations in both image and diffraction planes,and likewise separate the contributions of pre-and post-sample *** consideration provides insight into aberration-measurement techniques and might also indicate improvements for super-resolution techniques.

关键词： scanning transmission electron microscopy (STEM) aberrations

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Structural effects induced by dialysis-based purification of carbon nanomaterials

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Nano Materials Science 2024年第4期6卷 475-483页

作者： A.D.Veloso A.M.Ferraria A.M.Botelho do rego A.S.Viana A.j.S.Fernandes A.j.Fielding r.A.Videira M.C.Oliveira CQ-Vr and Chemistry Department University of Trás-os-Montes e Alto Douro BSIrG iBB-Institute for Bioengineering and BiosciencesDepartment of Chemical Engineeringand Associate Laboratory i4HB-Institute for Health and BioeconomyInstituto Superior TécnicoUniversidade de Lisboa Centro de Química Estrutural Institute of Molecular SciencesDepartamento de Química e BioquímicaFaculdade de CiênciasUniversidade de Lisboa I3N and Physics Department University of AveiroCampus de Santiago Faculty of Science Pharmacy and Biomolecular SchoolLiverpool John Moores University rEQUIMTE/LAQV Laborat orio de FarmacognosiaDepartamento de QuímicaFaculdade de Farm aciaUniversidade do Porto

Dialysis plays a crucial role in the purification of nanomaterials but its impact on the structural properties of carbon nanomaterials was never ***,a carbon-based nanomaterial generated electrochemically in potassium phosphate buffer,was characterized before and after dialysis against pure *** is shown that dialysis affects the size of the carbon domains,structural organization,surface functionalization,oxidation degree of carbon,and grade of ***,dialysis drives the nanomaterial organization from discrete roundish carbon domains,with sizes ranging from 70 to 160 nm,towards linear stacking structures of small nanoparticles （rallel,alcohol and ether （epoxide） surface groups evolve into more oxidized carbon groups （e.g.,ketone and ester groups）.Investigation of the as-prepared nanomaterial by electron paramagnetic resonance （EPr） revealed a resonance signal consistent with carbon-oxygen centred ***,this study brings to light the selective affinity of the carbon nanomaterial under study to capture Na+ions,a property greatly enhanced by the dialysis process,and its high ability to trap oxygen,particularly before *** findings open new perspectives for the application of carbon-based nanomaterials and raise awareness of the importance of structural changes that can occur during the purification of carbon-based nanomaterials.

关键词： Nanocarbon Surface functionalization NMr XPS Hydrophilic carbon Paramagnetic

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Comparison of methods for deriving phenotypes from incomplete observation data with an application to age at puberty in dairy cattle

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journal of Animal Science and Biotechnology 2024年第2期15卷 535-545页

作者： Melissa A.Stephen Chris r.Burke jennie E.Pryce Nicole M.Steele Peter r.Amer Susanne Meier Claire V.C.Phyn Dorian j.Garrick DairyNZ Ltd 605 Ruakura RoadHamilton 3240New Zealand AL rae Centre for Genetics and Breeding-Massey University RuakuraHamilton 3214New Zealand Agriculture Victoria research AgriBioCentre for AgriBioscienceBundooraVictoria 3083Australia School of Applied Systems Biology La Trobe UniversityBundooraVictoria 3083Australia AbacusBio DunedinNew Zealand

Background Many phenotypes in animal breeding are derived from incomplete measures,especially if they are challenging or expensive to measure *** include time-dependent traits such as reproductive status,or *** measures for these traits result in phenotypes that are subject to left-,interval-and rightcensoring,where phenotypes are only known to fall below an upper bound,between a lower and upper bound,or above a lower bound *** we compare three methods for deriving phenotypes from incomplete data using age at first elevation(>1 ng/mL)in blood plasma progesterone(AGEP4),which generally coincides with onset of puberty,as an example *** We produced AGEP4 phenotypes from three blood samples collected at about 30-day intervals from approximately 5,000 Holstein–Friesian or Holstein–Friesian×jersey cross-bred dairy heifers managed in 54 seasonal-calving,pasture-based herds in New *** used these actual data to simulate 7 different visit scenarios,increasing the extent of censoring by disregarding data from one or two of the three *** methods for deriving phenotypes from these data were explored:1)ordinal categorical variables which were analysed using categorical threshold analysis;2)continuous variables,with a penalty of 31 d assigned to right-censored phenotypes;and 3)continuous variables,sampled from within a lower and upper bound using a data augmentation *** Credibility intervals for heritability estimations overlapped across all methods and visit scenarios,but estimated heritabilities tended to be higher when left censoring was *** sires with at least 5 daughters,the correlations between estimated breeding values(EBVs)from our three-visit scenario and each reduced data scenario varied by method,ranging from 0.65 to *** estimated breed effects also varied by method,but breed differences were smaller as phenotype censoring *** Our results indicate that using

关键词： Cattle Gibbs sampler Markov-chain Monte Carlo(MCMC) Puberty

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Network analyses:Inhibition of androgen receptor signaling reduces inflammation in the lung through Ar-MAF-IL6 signaling axes

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Genes & Diseases 2024年第3期11卷 140-143页

作者： Albert r.Wang Andrew M.Baschnagel Zijian Ni Sean r.Brennan Hypatia K.Newton Darya Buehler Christina Kendziorski randall j.Kimple Gopal lyer Department of Human Oncology University of Wisconsin School of Medicine and Public HealthUniversity of WisconsinMadisonWI 53705USA Department of Biomedical Engineering University of Wisconsin-MadisonMadisonWI 53705USA University of Wisconsin Carbone Cancer Center MadisonWI 53705USA Department of Biostatistics and Medical Informatics University of Wisconsin-MadisonMadisonWI 53706USA Department of Biology Tufts UniversityMedfordMA 02155USA Department of Pathology and Laboratory Medicine University of Wisconsin School of Medicine and Public HealthUniversity of WisconsinMadisonWI 53705USA

Androgen receptor(Ar)is a major transcription factor that plays a role in inflammatory response including interleukin-6(IL6)signaling.1 While Ar regulation through paracrine loop signaling in prostate tissue is well-studied,its impact through an IL6 autocrine loop in the lung has not been wellstudied despite the organ's response to respiratory viral *** inhibition and rNA knockdown of Ar identified a bZIP transcription factor MAF to be a common target of inflammation using these perturbations in lung cells.

关键词： inflammation lung respiratory

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Mechanocatalysis of CO to CO_(2)on TiO_(2)surface controlled at atomic scale

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Nano research 2024年第7期17卷 5826-5834页

作者： Yuuki Adachi robert Turanský ján Brndiar Kamil Tokár Qiang Zhu Huan Fei Wen Yasuhiro Sugawara IvanŠtich Yan jun Li Department of Applied Physics Osaka University2-1 YamadaokaSuitaOsaka 565-0871Japan Institute of Physics Slovak Academy of SciencesBratislava 84511Slovakia Institute of Informatics Slovak Academy of SciencesBratislava 84507Slovakia Faculty of Natural Sciences University of Ss.Cyril and MethodiusTrnava 91701Slovakia Key Laboratory of Instrumentation Science and Dynamic Measurement School of Instrument and ElectronicsNorth University of ChinaTaiyuan 030051China

The common ways to activate a chemical reaction are by heat,electric current,or ***,mechanochemistry,where the chemical reaction is activated by applied mechanical force,is less common and only poorly understood at the atomic *** we report a tip-induced activation of chemical reaction of carbon monoxide to dioxide on oxidized rutile TiO_(2)(110)*** activation is studied by atomic force microscopy,Kelvin probe force microscopy under ultrahigh-vacuum and liquid nitrogen temperature conditions,and density functional theory(DFT)*** reaction is inferred from hysteretic behavior of frequency shift signal further supported by vector force mapping of vertical and lateral forces needed to trigger the chemical reaction with torque motion of carbon monoxide towards an oxygen *** reaction is found to proceed stochastically at very small tip-sample ***,the local contact potential difference reveals the atomic-scale charge redistribution in the reactants required to unlock the *** results open up new insights into the mechanochemistry on metal oxide surfaces at the atomic scale.

关键词： atomic resolution mechanochemistry atomic force microscopy Kelvin probe force microscopy density functional theory(DFT)simulation CO oxidation catalysis rutile TiO_(2)surface

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Opposite latitudinal gradients for species richness and phylogenetic diversity of endemic snakes in the Atlantic Forest

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Current Zoology 2024年第4期70卷 522-530页

作者： joséThales da Motta Portillo josuéAnderson rēgo Azevedo Fausto Erritto Barbo ricardo j.Sawaya Programa de Pos-Graduacao em Biologia Animal Instituto de BiocienciasLetras e Ciencias ExatasUniversidade Estadual Paulista"Julio de Mesquita Filho"Rua Cristovao Colombo2265Sao Josédo Rio PretoSao Paulo 15054-000Brazil Programa de Colecoes Cientificas Biologicas Coordenagao de BiodiversidadeInstituto Nacional de Pesquisas da AmazoniaAvenida AndréAraujo2936ManausAmazonas 69067-375Brazil Gothenburg Global Biodiversity Centre University of GothenburgBox 461GothenburgVastra Gotaland SE-40530Sweden Instituto Federal de Educacao Ciencia e Tecnologia de Minas GeraisRodovia Machado-Paraguacukm 3MachadoMinas Gerais 37750-000Rraizil Centro de Ciencias Naturais e Humanas UniversidadeFederaldo ABCRua Arcturus03Sao Bernardo do CampoSao Paulo09606-070Brazil

The decrease in species richness toward higher latitudes is an expected biogeographical *** pattern could be related to particular envi-ronmental constraints and the evolutionary history of ***,species richness does not fully represent the evolutionary history of the clades behind their *** diversity better clarifies the role of historical factors in biogeographical *** analyzed envi-ronmental and historical drivers related to latitudinal variation in species richness and phylogenetic diversity of Atlantic Forest endemic *** implemented species distribution models,from voucherbased locality points,to map the snake ranges and *** used generalized additive mixed models to evaluate the relationships among the diversity metrics and area,topographical roughness,and past climate change velocity since the Last Maximum Glacial in the Atlantic Forest latitudinal *** to the expected general pattern,species richness was higher toward higher latitudes,being positively related to past climatic *** richness also increased with total area and higher topographical *** diversity,on the other hand,showed opposite relationships related to the same *** diversity increased with lower climatic stability in lower ***,dimensions of diversity were affected in different ways by historical and environmental constraints in this unique and threatened biodiversity hotspot.

关键词： biodiversity latitudinal gradient neotropical region phylogenetic diversity serpents species richness.

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Kinematic analysis of flexible bipedal robotic systems

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Applied Mathematics and Mechanics(English Edition) 2024年第5期45卷 795-818页

作者： r.FAZEL A.M.SHAFEI S.r.NEKOO Department of Mechanical Engineering Shahid Bahonar University of KermanKerman ***Iran Departamento de Ingenieria de Sistemas y Automatica Escuela Técnica Superior de IngenieriaUniversidad de SevillaSeville 41092Spain

In spite of its intrinsic complexities,the passive gait of bipedal robots on a sloping ramp is a subject of interest for numerous *** distinguishes the present research from similar works is the consideration of flexibility in the constituent links of this type of robotic *** is not a far-fetched assumption because in the transient(impact)phase,due to the impulsive forces which are applied to the system,the likelihood of exciting the vibration modes increases ***,the human leg bones that are involved in walking are supported by viscoelastic muscles and ***,for achieving more exact results,it is essential to model the robot links with viscoelastic *** this end,the Gibbs-Appell formulation and Newton's kinematic impact law are used to derive the most general form of the system's dynamic equations in the swing and transient phases of *** most important issue in the passive walking motion of bipedal robots is the determination of the initial robot configuration with which the system could accomplish a periodic and stable gait solely under the effect of gravitational *** extremely unstable nature of the system studied in this paper and the vibrations caused by the impulsive forces induced by the impact of robot feet with the inclined surface are some of the very serious challenges encountered for achieving the above-mentioned *** overcome such challenges,an innovative method that uses a combination of the linearized equations of motion in the swing phase and the algebraic motion equations in the transition phase is presented in this paper to obtain an eigenvalue *** solving this problem,the suitable initial conditions that are necessary for the passive gait of this bipedal robot on a sloping surface are *** effects of the characteristic parameters of elastic links including the modulus of elasticity and the Kelvin-Voigt coefficient on the walking stability of this type of

关键词： bipedal robot flexible link swing phase transient phase eigenvalue problem Kelvin-Voigt coefficient

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Holographic dark energy in non-conserved gravity theory

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Communications in Theoretical Physics 2024年第4期76卷 126-133页

作者： H r Fazlollahi Institute of Gravitation and Cosmology Peoples Friendship University of Russia(RUDN University)6 Miklukho-Maklaya StMoscow117198Russia

recently, reconsidering the rastall idea T_(μ;νν)^(v)=α_(,μ) through relativistic thermodynamics gives a new form for the scalar field α which led us to construct modern modified theory of gravity debugged ‘non-conserved gravity theory’ Fazlollahi 2023 Euro. Phys. j. C 83 923. This theory unlike other modified theories of gravity cannot directly explain the current acceleration expansion in the absence of the cosmological constant and or existence of other forms of dark energy. Hence, in this study we have reinvestigated holographic dark energy Ρ_(X)~H^(2) in the non-conserved theory of gravity. In this context, the density and pressure of dark energy depend on the non-conserved term and density of the dust matter field. As shown, due to non-conservation effects on large-scale structures, unlike the original holographic model, our model onsets an acceleration epoch for the current Universe satisfies observations. Moreover, the interaction and viscous scenarios are studied for this model.

关键词： non-conserved gravity covariant form of thermodynamics holographic dark energy

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Sustained adenosine release:revealing its impact on osteogenic signalling pathways of human mesenchymal stromal cells

Engineered Regeneration

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Engineered regeneration 2024年第2期5卷 255-268页

作者： Hadi Hajiali jane McLaren Cristina Gonzalez-García Salah Abdelrazig Dong-Hyun Kim Matthew j.Dalby Manuel Salmerón-Sánchez Felicity r.A.j.rose School of Pharmacy Nottingham Biodiscovery InstituteUniversity of NottinghamNottinghamUK Healthcare Technologies Institute School of Chemical EngineeringUniversity of BirminghamBirminghamUK Centre for the Cellular Microenvironment University of GlasgowGlasgowUK Centre for Analytical Bioscience Advanced Materials&Healthcare Technologies DivisionSchool of PharmacyUniversity of NottinghamNottinghamUK Marine Microbiomics Program in BiologyDivision of Science and MathematicsNew York University Abu Dhabi(NYUAD)P.O.Box 129188Abu DhabiUnited Arab Emirates

Non-healing fractures,a global health concern arising from trauma,osteoporosis,and tumours,can lead to severe ***,integral to cellular energy metabolism,gains prominence in bone regeneration via adeno-sine A2 B receptor *** study introduces a controlled-release system for localized adenosine delivery,fostering human mesenchymal stromal cell(hMSC)differentiation into functional bone *** study investi-gates how the ratio of lactic acid to glycolic acid in microparticles can influence adenosine release and explores the downstream effects on gene expression and metabolic profiles of osteogenic differentiation in hMSCs cultured in growth and osteoinductive *** into adenosine-modulated signalling pathways during MSC differenti-ation,with osteogenic factors,provide a comprehensive understanding of the pathways *** gene expression and metabolic profiles unravels adenosine’s regulatory mechanisms in MSC *** adenosine release from microparticles induces mineralization,synergizing with osteogenic media supplements,showcasing the potential of adenosine for treating critical bone defects and metabolic *** study high-lights the efficacy of a polymeric microparticle-based delivery system,offering novel strategies for bone *** adenosine’s roles and associated signalling pathways advances our comprehension of molecular mech-anisms steering bone regeneration,propelling innovative biomaterial,combined with metabolites,approaches for clinical use.

关键词： Adenosine release Osteogenic signalling pathways Human mesenchymal stromal cells Bone regeneration

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