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Dynamic stress concentration in an infinitely long cylindrical cavity due to a point spherical source embedded within a fluid-saturated poroelastic formation of infinite extent

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Applied Mathematics and Mechanics(English Edition) 2025年第1期46卷 139-156页

作者： H.HoSSEINI o.BALILASHAKI Department of Mechanical Engineering Faculty of EngineeringGolestan University

The effects of a harmonically exciting monopole source on an infinitely long cylindrical cavity embedded entirely within a fluid-saturated poroelastic formation of infinite extent are examined theoretically. It is assumed that the source is located outside the cavity at a specified distance from the borehole axis. The magnitudes of the hoop and radial stresses beside the pore pressures exerted on the interface and inside the porous medium surrounding the borehole are calculated and discussed. Biot's poroelastic modeling along with three types of boundary conditions for the cylindrical interface including the ideal fluid, empty borehole, and rigid inclusion with a hard boundary is employed for the analysis. Utilizing a proper translational addition theorem for expressing the incident spherical wave in terms of cylindrical wave expansions, the proposed boundary conditions at the interface are satisfied. Stresses are formulated by means of wave potential functions in a three-dimensional(3D) manner. The effects of the frequency and the radial distance between the source and borehole on the induced stresses are examined for the first cylindrical modes over frequency spectra. Two permeability conditions for the interface and three types of soils for the porous formation are considered throughout the analysis. To give an overall outline of the study, a numerical example is presented. The results clearly indicate that the distance is a key parameter and has considerable effects on the induced stress values. In addition, the interface permeability condition and soil characteristics play an important role in determining the dynamic response of the borehole. Finally,the obtained results are compared with the relevant analyses existing in the literature for some limit cases, and good agreement is achieved.

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A Characterization of Linearly Semisimple Groups

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Acta Mathematica Sinica,English Series 2011年第1期27卷 185-192页

作者： Amelia alvare.Z Pedro SANCHo Carlos SANCHo Departamento de Matemdticas Universidad de Extremadura Avenida de Elvas s/n 06006 Badajoz Spain Departamento de Matemdticas Universidad de Salamanca Plaza de la Merced 1-4 37'008 Salamanca Spain

Let G -- Spec A be an affine K-group scheme and A = （w ∈ A＊： dimK A＊-w 〈 ∞, dimK w. A＊〈 ∞}. Let （-, -）： A＊ × A → K, （w, w）：= tr（ww）, be the trace form. We prove that G is linearly reductive if... 详细信息

Let G -- Spec A be an affine K-group scheme and A = （w ∈ A＊： dimK A＊-w 〈 ∞, dimK w. A＊〈 ∞}. Let （-, -）： A＊ × A → K, （w, w）：= tr（ww）, be the trace form. We prove that G is linearly reductive if and only if the trace form is non-degenerate on A＊.

关键词： Linearly reductive group trace form Pontrjagin's duality

Neuroinflammation revisited through the microglial lens

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Neural Regeneration Research 2025年第7期20卷 1989-1990页

作者： Renato Socodato João B.Relvas Institute of Research and Innovation in Health(i3S)and Institute for Molecular and Cell Biology(IBMC) University of PortoPortoPortugal Department of Biomedicine Faculty of Medicine of the University of Porto(FMUP)PortoPortugal

Neuroimmunology is emerging as a pivotal field,shedding light on the intricate dialogues between the central nervous system(CNS)and the immune *** exploration is particularly significant in understanding microglia,the CNS’s innate immune cells,beyond the conventional conflation of“neuroinflammation”and“microglial activation.”This conflation has clouded the true complexity of these processes,potentially stalling scientific progress and the development of new *** challenge the long-standing perspectives that have oversimplified these interactions,advocating for a deeper exploration of the dynamic relationship between neuroinflammation and microglial *** dissecting specific molecular pathways,we aim to illuminate their elaborate roles in neuroinflammatory responses,especially in the context of Alzheimer’s disease(AD).Here,neuroinflammation is not merely a passive observer or a direct antagonist but a complex agent in the disease’s *** article calls for a significant paradigm shift towards an integrative,multi-omics approach to *** such a comprehensive framework is crucial for advancing our understanding of neuroinflammatory conditions and paving the way for targeted therapeutic strategies for brain diseases.

关键词： inflammation simplified activation

Contribution of mechanical forces to structural synaptic plasticity:insights from 3D cellular motility mechanisms

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Neural Regeneration Research 2025年第7期20卷 1995-1996页

作者： Rita o.Teodoro Mafalda Ribeiro Ramos Lara Carvalho iNoVA4Health NOVA Medical School|Faculdade de Ciências MédicasNMS|FCMUniversidade Nova de LisboaLisboaPortugal

Cells,tissues,and organs are constantly subjected to the action of mechanical forces from the extracellular environment-and the nervous system is no ***-intrinsic properties such as membrane lipid composition,abundance of mechanosensors,and cytoskeletal dynamics make cells more or less likely to sense these *** and extrinsic cues are integrated by cells and this combined information determines the rate and dynamics of membrane protrusion growth or retraction(Yamada and Sixt,2019).Cell protrusions are extensions of the plasma membrane that play crucial roles in diverse contexts such as cell migration and neuronal synapse *** the nervous system,neurons are highly dynamic cells that can change the size and number of their pre-and postsynaptic elements(called synaptic boutons and dendritic spines,respectively),in response to changes in the levels of synaptic activity through a process called *** plasticity is a hallmark of the nervous system and is present throughout our lives,being required for functions like memory formation or the learning of new motor skills(Minegishi et al.,2023;Pillai and Franze,2024).

关键词： plasticity structural mechanisms

Apples to oranges:environmentally derived,dynamic regulation of serotonin neuron subpopulations in adulthood?

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Neural Regeneration Research 2025年第9期20卷 2596-2597页

作者： Christopher J.o’Connell Matthew J.Robson Department of Genetics College of MedicineHarvard UniversityBostonMAUSA James L.Winkle College of Pharmacy Division of Pharmaceutical SciencesUniversity of CincinnatiCincinnatiOHUSA Neuroscience Graduate Program College of MedicineUniversity of CincinnatiCincinnatiOHUSA

Traumatic brain injury(TBI)is a public health problem with an undue economic burden that impacts nearly every age,ethnic,and gender group across the globe(Capizzi et al.,2020).TBIs are often sustained during a dynamic range of exposures to energetic environmental forces and as such outcomes are typically heterogeneous regarding severity and pathology(Capizzi et al.,2020).

关键词： sustained orange dynamic

合成二氧化氯的催化剂和方法及该催化剂的制备

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绿箭信息 2000年第2期1卷 25-28页

作者： Patr.,DF danie.,o

使用一种失活速率降低的催化剂用亚氯酸钠的水溶液合成二氧化氮。催化剂最好为钯，钯与其它钯系金属的混合物（如Ｐｂ＋Ｐｔ）或者是钯与第１副族金属的混合物（Ｐｂ＋Ａｕ），所用的载体为可用第１主族金属的硕酸盐如（Ｋ２ＣＯ３）、... 详细信息

使用一种失活速率降低的催化剂用亚氯酸钠的水溶液合成二氧化氮。催化剂最好为钯，钯与其它钯系金属的混合物（如Ｐｂ＋Ｐｔ）或者是钯与第１副族金属的混合物（Ｐｂ＋Ａｕ），所用的载体为可用第１主族金属的硕酸盐如（Ｋ２ＣＯ３）、第２主族金属的碳酸盐（如ＣａＣＯ３）或者是可转化成ＭｇＯ的镁盐改性的物质，载体还可以是第１主族金属的碳酸盐（如Ｋ２ＣＯ３）或者是可转化成ＭｇＯ的镁盐改性的物质。

关键词：二氯化氯合成方法催化剂金属催化剂制备

New 0D/1D Physical Approach for Modelling the Gas Dynamics Behavior Inside the Intake System of an Engine

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Journal of Thermal Science 2018年第4期27卷 394-403页

作者： David CHALET Mohamad YASSINE Jérome MIGAUD Ecole Centrale de Nantes LHEEA lab. (ECN/CNRS) Nantes France MANN+HUMMEL France Laval France

The competition among carmakers to introduce the most innovative solutions is growing day by day. Since few years, simulation is being used widely in automotive industries. Instead of building costly prototypes and expending fuel for doing tests on a real engine, simulation became a good solution before taking new decisions. Concerning the study of gas dynamics and pressure wave's propagation in the intake system of an internal combustion engine, a precise modelling is needed in order to obtain good results. Unfortunately, the computational time for these simulations is considered as high compared to the real time. The main objective of the new approach presented in this paper, is to reduce simulation time of models in the internal combustion engine simulation code, allowing them to accomplish many engine simulations faster than one-dimensional non-linear approach. A transfer function is defined to link directly the relative pressure and the air mass flow rate. In a second time, the model is included into an internal combustion engine simulation code. The results obtained with this code are compared to experimental ones which are measured on a one-cylinder engine test bench. A good agreement is obtained between the experimental results and the numerical one. The model was improved by adding a transfer function for temperature evolution. The convergence time is then reduced as well as the global simulation time of the model.

关键词： gas dynamics compressible flow transfer function accuracy simulation time engine

Nanobubble generation and its applications in froth flotation(part IV):mechanical cells and specially designed column flotation of coal

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Mining Science and Technology 2010年第5期20卷 641-671页

作者： FAN Maoming TAo danie.HoNAKER Rick LUo Zhenfu Department of Mining Engineering University of Kentucky Lexington KY 40506 USA CPT Eriez Manufacturing Co Erie PA 16514 USA School of Chemical Engineering and Technology China University of Mining & Technology Xuzhou 221116 China

Coal is the world's most abundant fossil *** froth flotation is a widely used cleaning process to separate coal from mineral *** of coarse coal particles,ultrafine coal particles and oxidized coal particles is well known to be difficult and *** this paper,the nanobubbles' effects on the flotation of the varying particle size,particle density and floatability coal samples were evaluated using a bank of pilot scale flotation cells,a laboratory scale and a pilot scale specially designed flotation *** parameters evaluated during this study include the flow rate ratio between the nanobubble generator and the conventional size bubble generator,the superficial air velocity,collector dosage,frother concentration,flotation feed rate,feed solids concentration,feed particle size,and the superficial wash water flow rate,*** results show that the use of nanobubbles in a bank of mechanical cells flotation and column flotation increased the flotation recovery by 8%～27% at a given product *** increased the flotation rate constants of 600～355,355～180,180～75,and 75～0 microns size coal particles by 98.0%,98.4%,50.0% and 41.6%,*** separation selectivity index was increased by up to 34%,depending on the flotation feed characteristics and the flotation conditions.

关键词： coal froth flotation cavitation nanobubble flotation kinetics

1973年能源价格上涨后能源的消费与经济发展

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世界石油科学 1995年第1期 8-16页

作者：杜金亮 danie.,J