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Nonlinear forced vibration in a subcritical regime of a porous functionally graded pipe conveying fluid with a retaining clip

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Applied mathematics and mechanics(English Edition) 2025年第1期46卷 101-122页

作者： m.GHOLAmI m.EFTEKHARI Department of mechanical Engineering Shahid Bahonar University of Kerman

This study examines the nonlinear behaviors of a clamped-clamped porous pipe made of a functionally graded material(FGm) that conveys fluids and is equipped with a retaining clip, focusing on primary resonance and subcritical dynamics. The nonlinear governing equations for the FGm pipe are derived by the extended Hamilton's principle, and subsequently discretized through the application of the Galerkin *** direct method of multi-scales is then used to solve the derived equations. A thorough analysis of various parameters, including the clip stiffness, the power-law index, the porosity, and the clip location, is conducted to gain a comprehensive understanding of the system's nonlinear dynamics. Through the analysis of the first natural frequency, the study highlights the influence of the flow velocity and the clip stiffness, while the comparisons with metallic pipes emphasize the role of FGm composition. The examination of the forced response curves reveals saddle-node bifurcations and their dependence on parameters such as the detuning parameter and the power-law index, offering valuable insights into the system's nonlinear resonant behavior. Furthermore, the frequency-response curves illustrate the hardening nonlinearities influenced by factors such as the porosity and the clip stiffness, revealing nuanced effects on the system response and resonance characteristics. This comprehensive analysis enhances the understanding of nonlinear behaviors in FGm porous pipes with a retaining clip, providing key insights for practical engineering applications in system design and optimization.

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EBSD Investigation on Effect of Cooling Rate on microstructure and Transformation Textures of High Strength Hot-rolled Steel Plates

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Journal of Iron and Steel Research International 2016年第3期23卷 261-269页

作者： Nancy m.lopez GRANADOS Armando SALINAS RODRIGUEZ Department of metallurgical Engineering and materials Science Center of Research and Advanced StudiesCINVESTAV-Unidad Saltillo

The effect of cooling rate on the microstructure and transformation textures of high strength hot-rolled steels was *** treated samples subjected to different cooling conditions were characterized by optical and scanning electron microscopes using orientation imaging microscopy（OIm）.The experimental results demonstrate that there is a significant effect of cooling rate on microstructures and textures resulting from phase *** cooling rates lead to the appearance of the cube（001）[010],rotated cube（001）[110]/（001）[110],Goss（110）[001]and rotated Goss（110）[110]*** contrast,textures developed at rapid cooling rates are preferably of Cu（112）[111],Br（110）[112],transformed Cu（113）[110]and transformed Br（332）[113]/（112）[131].These texture changes are attributed to the selective character of the phase *** OIm technique was used to have a better understanding of the formation of phases and their relationship between microstructure and processing *** volume fraction of micro-constituents resulting from phase transformation such as bainite,martensite and different types of ferrite,can be measured satisfactorily by this technique correlating image quality of EBSD patterns to specific phases.

关键词： orientation imaging microscopy texture phase transformation microstructure steel

Neurogenesis dynamics in the olfactory bulb:deciphering circuitry organization, function, and adaptive plasticity

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Neural Regeneration Research 2025年第6期20卷 1565-1581页

作者： moawiah m.Naffaa Department of Psychology and Neuroscience Duke UniversityDurhamNCUSA Department of Cell Biology Duke University School of MedicineDurhamNCUSA

Adult neurogenesis persists after birth in the subventricular zone, with new neurons migrating to the granule cell layer and glomerular layers of the olfactory bulb, where they integrate into existing circuitry as inhibitory interneurons. The generation of these new neurons in the olfactory bulb supports both structural and functional plasticity, aiding in circuit remodeling triggered by memory and learning processes. However, the presence of these neurons, coupled with the cellular diversity within the olfactory bulb, presents an ongoing challenge in understanding its network organization and function. moreover,the continuous integration of new neurons in the olfactory bulb plays a pivotal role in regulating olfactory information processing. This adaptive process responds to changes in epithelial composition and contributes to the formation of olfactory memories by modulating cellular connectivity within the olfactory bulb and interacting intricately with higher-order brain regions. The role of adult neurogenesis in olfactory bulb functions remains a topic of debate. Nevertheless, the functionality of the olfactory bulb is intricately linked to the organization of granule cells around mitral and tufted cells. This organizational pattern significantly impacts output, network behavior, and synaptic plasticity, which are crucial for olfactory perception and memory. Additionally, this organization is further shaped by axon terminals originating from cortical and subcortical regions. Despite the crucial role of olfactory bulb in brain functions and behaviors related to olfaction, these complex and highly interconnected processes have not been comprehensively studied as a whole. Therefore, this manuscript aims to discuss our current understanding and explore how neural plasticity and olfactory neurogenesis contribute to enhancing the adaptability of the olfactory system. These mechanisms are thought to support olfactory learning and memory, potentially through increased

关键词： network adaptability neurogenesis neuronal communication olfactory bulb olfactory learning olfactory memory synaptic plasticity

mitochondria–cGAS–STING axis is a potential therapeutic target for senescence-dependent inflammaging-associated neurodegeneration

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Neural Regeneration Research 2025年第3期20卷 805-807页

作者： Josém.Izquierdo Centro de Biología molecular Severo Ochoa(CBm) Consejo Superior de Investigaciones Científicas-Universidad Autónoma de Madrid(CSIC-UAM)MadridSpain

The word “senescence” comes from the Latin senescens, meaning “to begin to age”, and is characterized by a long-lasting but reversible block in proliferation, resulting from stress-induced cell cycle arrest of pre... 详细信息

关键词： Latin potential lasting

Broadband vectorial ultrathin optics with experimental efficiency up to 99%in the visible region via universal approximators

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Light(Science & Applications) 2021年第3期10卷 420-433页

作者： F.Getman m.makarenko A.Burguete-lopez A.Fratalocchi PRImALIGHT Faculty of Electrical EngineeringApplied Mathematics and Computational ScienceKing Abdullah University of Science and TechnologyThuwal 23955-6900Saudi Arabia

Integrating conventional optics into compact nanostructured surfaces is the goal of flat *** the enormous progress in this technology,there are still critical challenges for real-world applications due to the limited operational efficiency in the visible region,on average lower than 60%,which originates from absorption losses in wavelengththick(~500 nm)*** issue is the realization of on-demand optical components for controlling vectorial light at visible frequencies simultaneously in both reflection and transmission and with a predetermined wavefront *** this work,we developed an inverse design approach that allows the realization of highly efficient(up to 99%)ultrathin(down to 50 nm thick)optics for vectorial light control with broadband input-output responses in the visible and near-IR regions with a desired wavefront *** approach leverages suitably engineered semiconductor nanostructures,which behave as a neural network that can approximate a user-defined input-output *** performance results from the ultrathin nature of these surfaces,which reduces absorption losses to nearnegligible ***,we discuss polarizing beam splitters,comparing their performance with the best results obtained from both direct and inverse design techniques,and new flat-optics components represented by dichroic mirrors and the basic unit of a flat-optics display that creates full colours by using only two subpixels,overcoming the limitations of conventional LCD/OLED technologies that require three subpixels for each composite *** devices can be manufactured with a complementary metal-oxide-semiconductor(CmOS)-compatible process,making them scalable for mass production at low cost.

关键词： optics visible inverse

On SIR epidemic models with generally distributed infectious periods： Number of secondary cases and probability of infection

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International Journal of Biomathematics 2017年第2期10卷 157-169页

作者： A. Gomez-Corral m. lopez-Garcia Instituto de Ciencias matemdticas CSIC- UAM- UC3M- UCM Calle Nicolds Cabrera 13-15 Madrid 28049 Spain Department of Applied mathematics School of Mathematics University of Leeds Leeds LS29JT UK

Recently, Clancy [SIR epidemic models with general infectious period distribution, Statist. Prob. Left. 85 （2014） 1-5] has shown how SIR epidemics in which individuals＇ infection periods are not necessarily exponentially distributed may be modeled in terms of a piecewise-deterministic markov process （PDmP）. In this paper, we present a more detailed description of the underlying PDmP, from which we analyze the population transmission number and the infection probability of a certain susceptible individual.

关键词： Number of secondary cases piecewise-deterministic markov process proba-bility of infection SIR epidemic model.

OBSERVATION OF NONLINEAR VERTICUm-TYPE SYSTEmS APPLIED TO ECOLOGICAL mONITORING

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International Journal of Biomathematics 2012年第6期5卷 61-75页

作者： S. mOLNAR m. GAmEZ lopez Institute of mathematics and Informatics Szent Istvdn University Department of Statistics and Applied mathematics University of Almer~a La Carada de San Urbano 04120 Almerla Spain

In this paper the concept of a nonlinear verticumtype observation system is introduced. These systems are composed from several ＂subsystems＂ connected sequentially in a particular way： a part of the state variables of each ＂subsystem＂ also appears in the next ＂subsystem＂ as an ＂exogenous variable＂ which can also be interpreted as a con trol generated by an ＂exosystem＂. Therefore these ＂subsystems＂ are not observation systems, but formally can be considered as controlobservation systems. The problem of observability of such systems can be reduced to rank conditions on the ＂subsystems＂. Indeed, under the condition of Lyapunov stability of an equilibrium of the ＂large＂, verticumtype system, it is shown that the Kalman rank condition on the linearization of the ＂subsystems＂ implies the observability of the original, nonlinear verticumtype system. For an illustration of the above linearization result, a stagestructured fishery model with reserve area is considered. Observability for this system is obtained by applying the above linearization and decomposition approach. Furthermore, it is also shown that, applying an appropriate observer design method to each subsystem, from the observa tion of the biomass densities of the adult （harvested） stage, in both areas, the biomass densities of the prerecruit stage can be efficiently estimated.

关键词： Verticum-type system nonlinear system observability observer design fishery with reserve area.

Transport mechanism in chemically reactive hybrid nanofluid flow containing gyrotactic micro-organisms over a curved oscillatory surface

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Applied mathematics and mechanics(English Edition) 2025年第1期46卷 177-192页

作者： m.NAVEED m.ImRAN T.ASGHAR Z.ABBAS Department of mathematics Division of Science and TechnologyUniversity of Education Department of mathematics The Islamia University of Bahawalpur

This paper examines the transport analysis, including both heat transfer and mass transfer, in hybrid nanofluid flow containing gyrotactic microorganisms towards a curved oscillatory surface. The influence of magnetic fields is also inspected in terms of their physical characteristics. To depict the phenomena of transport, modified versions of both Fick's and Fourier's laws are used. Additionally, the characteristics of both heterogeneous and homogeneous chemical reactions are also incorporated. Utilizing a curvilinear coordinate system, the flow problem is formulated as partial differential equations(PDEs)for momentum, concentration, microorganism field, and energy. An analytical solution to the obtained flow equations is achieved utilizing the homotopy analysis method(HAm).The effects of significant flow parameters on the pressure and microorganism fields, velocity, oscillation velocity, concentration, and temperature distributions are shown via graphs. Furthermore, the variations in skin friction, mass transfer rate, heat transfer rate, and local motile number due to different involved parameters are presented in tables and are analyzed in detail. Graphical results indicate that the curves of velocity and temperature fields are enhanced as the values of the solid volume fraction variables *** is also verified that the concentration rate field decreases as the values of the homogeneous reaction strength parameter and the radius of curvature parameter increase, and it increases with the Schmidt number and the heterogeneous reaction strength *** outcomes show a favorable response of the motile number to advanced values of the Peclet number, the Schmidt number, the microorganism difference parameter, and the bio-convective Lewis number.

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Brain-penetrating neurotrophic factor mimetics: HER-096 as a disease-modifying therapy for Parkinson’s disease

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Neural Regeneration Research 2025年第4期20卷 1094-1095页

作者： Natalia Kulesskaya Kira m.Holmström Henri J.Huttunen Herantis Pharma Plc EspooFinland

Neurotrophic factors as a therapeutic approach in neurodegenerative diseases:A major unmet need in the field of central nervous system diseases is disease-modifying *** for decades there have been various symptomatic treatments available to alleviate the symptoms of the disease,disease-modification,*** that stop,significantly delay,or reverse the progression of the disease,has been turned out to a difficult goal to achieve.

关键词： diseases treatment therapeutic