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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.

关键词： cylindrical cavity O353.4 point source porous medium stress concentration wave-field transformation

Multi-Objective optimization for stable and efficient cargo transportation of partial space elevator

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Defence Technology(防务技术) 2025年第2期44卷 17-29页

作者： Gefei Shi Zheng h.Zhu School of Aeronautics and Astronautics Sun Yat-sen UniversityGuangzhou 510275China Shenzhen Key Laboratory of Intelligent Microsatellite Constellation Shenzhen 518107China Department of Mechanical Engineering York University4700 Keele StreetTorontoCanada

This paper proposed a new libration decoupling analytical speed function(LD-ASF)in lieu of the classic analytical speed function to control the climber's speed along a partial space elevator to improve libration stability in cargo *** LD-ASF is further optimized for payload transportation efficiency by a novel coordinate game theory to balance competing control objectives among payload transport speed,stable end body's libration,and overall control input via model predictive *** transfer period is divided into several sections to reduce computational *** validity and efficacy of the proposed LD-ASF and coordinate game-based model predictive control are demonstrated by computer *** results reveal that the optimized LD-ASF results in higher transportation speed,stable end body's libration,lower thrust fuel consumption,and more flexible optimization space than the classic analytical speed function.

关键词： Partial space elevator Stable transportation Libration decoupling analytical speed function Coordinate game Model predictive control Pareto optimization

ON ThE GAUSSIAN KINEMATIC FORMULA OF *** AND ***

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Acta Mathematica Scientia 2025年第1期45卷 200-214页

作者： Joseph h.G.Fu Department of Mathematics University of GeorgiaAthensGA30602USA

We apply methods of algebraic integral geometry to prove a special case of the Gaussian kinematic formula of *** idea,suggested already by Adler and Taylor,is to view the GKF as the limit of spherical kinematic formul... 详细信息

关键词： integral geometry kinematic formula probability density Gaussian density

Neuroinflammation as a therapeutic target in huntington's disease

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Neural Regeneration Research 2025年第3期20卷 817-818页

作者： Andrea Kwakowsky Thulani h.Palpagama Center for Brain Research and Department of Anatomy and Medical Imaging Faculty of Medical and Health SciencesUniversity of AucklandAucklandNew Zealand Pharmacology and Therapeutics School of MedicineGalway Neuroscience CentreUniversity of GalwayGalwayIreland

In 1872, George huntington presented his essay “On Chorea” to the Meigs and Mason Academy of Medicine and, in doing so, detailed a disease that would later bear his name. huntington's disease(hD) is a genetic, neurodegenerative disease that manifests as the loss of motor control,cognitive impairment,and mood and psychiatric changes in paents.

关键词： huntington inflammation Medicine

Glial response in the midcingulate cortex in huntington’s disease

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Neural Regeneration Research 2025年第1期20卷 207-208页

作者： Thulani h.Palpagama Andrea Kwakowsky Center for Brain Research and Department of Anatomy and Medical Imaging Faculty of Medical and Health SciencesUniversity of AucklandAucklandNew Zealand Pharmacology and Therapeutics School of MedicineGalway Neuroscience CenterUniversity of GalwayGalwayIreland

huntington’s disease(hD)is a genetic disease characterized by the progressive degeneration of the striatum and *** can present with a variety of symptoms that can broadly be classified into motor symptoms,inclusive of choreatic movements and rigidity,mood and psychiatric symptoms,such as depression and apathy,and cognitive symptoms,such as cognitive *** causal mutation underlying hD results from an expansion of a CAG repeat sequence on the IT15 gene,resulting in the formation and accumulation of a mutant huntingtin protein.

关键词： huntington degeneration cortex

Comparative chemical sensor for detection of chromium(Ⅵ) in aqueous solution

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Optoelectronics Letters 2025年第1期21卷 21-27页

作者： Sura h.AL-REKABI A.A.ALWAhIB Electrical Technique Department Al Suwayrah Technical InstituteMiddle Technical UniversityBaghdadIraq Laser and Optoelectronics Department University of Technology-IraqBaghdadIraq

A process for purifying aqueous solutions containing heavy and toxic metals such as chromium(Cr) has been *** of the extremely harmful pollutants in rivers and seawater is the heavy metal ions due to their direct impacts on human,animals and plants are hexavalent Cr(Ⅵ).Consequently,highly sensitive sensor to detect Cr is *** plasmon resonance(SPR) technique has attracted huge research interest in detecting heavy metals *** this study,three types of prism-based SPR sensor,gold(Au)/silver(Ag),Au/polyaniline(PANI) and Au/titanium dioxide(TiO_(2)) nanostructured films,are investigated as potential sensing material to detect the presence of Cr(Ⅵ) ions in *** base Au layer with thickness of 48.3 nm is deposited on a glass slide for all *** Au/Ag,Au/PANI nanofibers and Au/TiO_(2) sensor films,the Cr(Ⅵ) concentration is varied from 1 ppm to 15 ppm with sensitivity of 0.270 °ppm^(-1),0.082 °ppm^(-1) and 0.039 °ppm^(-1),*** on these results,the Au/PANI nanofibers are the most sensitive to Cr(Ⅵ) among the tested sensing materials.

关键词： chromium fibers silver

Mossbauer,optical and structural properties of Fe^(3+) ion in borate glass

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Journal of Rare Earths 2025年第1期43卷 162-170,I0006页

作者： Essam A.Elkelany hesham Y.Amin A.Samir M.M.EL-hady h.h.El-Bahnasawy Moukhtar A.hassan Basic Science Department Faculty of EngineeringSinai UniversityAl-Arish45511Egypt School of Information and Electrical Engineering Hangzhou City UniversityHangzhou30015China State Key Laboratory of Modern Optical Instrumentation College of Optical Science and EngineeringZhejiang UniversityHangzhou310027China Basic Science Department Faculty of Engineering at ShoubraBenha University11629Egypt Physics Department Faculty of ScienceAl-Azhar University11884CairoEgypt

Lanthanum-bearing iron lithium borate glass is a quaternary system for oxide glasses and was prepared via the melt-quenching *** present article correlates the structure,optical,ligand field and M?ssbauer data on iron lithium borate glass co ntaining La^(3+).The density was measured,while the molar volume was *** physical parameters are *** increasing the La_(2)O_(3) content within the glass network,infrared spectra analysis reveals structural modifications such as the increase in BO_(4) units and the decline in both BO_(3) units and NBO bonds ***,optical absorption spectra were *** absorption spectra disclose a plethora of electronic transitions that are related to Fe^(3+)in tetrahedral and octahedral sites,however,Fe^(2+)phase is not observed in optical spectra,but it has a clear signature in M?ssbauer ***,the glass absorption edges undergo a clear blue shift,reflecting an increased band gap energy(1.96-2.28 eV).The decline in NBO bonds justifies this ***,the values of crystal field splitting are increased,while the values of Racah parameters are *** trend is justified by the decline in NBO bonds and increases electron localization around Fe cations.M?ssbauer spectra confirm the existence of Fe^(3+)in tetrahedral and octahedral sites,while Fe^(2+)exists in only a tetrahedral *** increasing La_(2)O_(3) content,the isomer shift of Fe^(3+)in tetrahedral sites changes to be 0.312-0.329 mm/s,while the isomer shift of octahedral Fe^(3+)is 0.424-0.456 mm/*** findings coincide with optical *** the isomer shift of tetrahedral Fe^(2+)is 0.902-0.911 mm/*** results of structural,optical and ligand field associated with M?ssbauer spectra open more vistas toward the utility of these samples in the optics realm.

关键词： Fe3+ions Rare-earth oxide Mossbauer spectra Ligand field parameters Optical properties

Characterization and source apportionment of volatile organic compounds in hong Kong:A 5-year study for three different archetypical sites

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Journal of Environmental Sciences 2025年第5期151卷 424-440页

作者： Yuchen Mai Vincent Cheung Peter K.K.Louie Kenneth Leung Jimmy C.h.Fung Alexis K.h.Lau Donald R.B.lake Dasa Gu Division of Environment and Sustainability The Hong Kong University of Science and TechnologyHong Kong 999077China Environmental Protection Department Hong Kong 999077China Environment and Ecology Bureau Hong Kong 999077China Department of Chemistry University of CaliforniaIrvine 92617USA

Initial success has been achieved in hong Kong in controlling primary air pollutants,but ambient ozone levels kept increasing during the past three *** organic compounds(VOCs)are important for mitigating ozone pollution as its major *** study analyzed VOC characteristics of roadside,suburban,and rural sites in hong Kong to investigate their compositions,concentrations,and source *** showthat the TVOC concentrations were 23.05±13.24,12.68±15.36,and 5.16±5.48 ppbv for roadside,suburban,and rural sites between May 2015 to June 2019,*** using Positive Matrix Factorization(PMF)model,six sources were identified at the roadside site over five years:Liquefied petroleum gas(LPG)usage(33%–46%),gasoline evaporation(8%–31%),aged air mass(11%–28%),gasoline exhaust(5%–16%),diesel exhaust(2%–16%)and fuel filling(75–9%).Similarly,six sources were distinguished at the suburban site,including LPG usage(30%–33%),solvent usage(20%–26%),diesel exhaust(14%–26%),gasoline evaporation(8%–16%),aged air mass(4%–11%),and biogenic emissions(2%–5%).At the rural site,four sources were identified,including aged airmass(33%–51%),solvent usage(25%–30%),vehicular emissions(11%–28%),and biogenic emissions(6%–12%).The analysis further revealed that fuel filling and LPG usage were the primary contributors to OFP and Oh reactivity at the roadside site,while solvent usage and biogenic emissions accounted for almost half of OFP and Oh reactivity at the suburban and rural sites,*** findings highlight the importance of identifying and characterizing VOC sources at different sites to help policymakers develop targeted measures for pollution mitigation in specific areas.

关键词： Volatile organic compounds Positive matrix factorization Source apportionment Ozone formation

Does mesenchymal stem cell’s secretome affect spinal sensory circuits?Implication for pain therapies

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Neural Regeneration Research 2025年第1期20卷 181-183页

作者： Francesco Ferrini Esri h.Juárez Adalberto Merighi Department of Veterinary Sciences University of TurinGrugliascoTOItaly Department of Psychiatry and Neuroscience UniversitéLavalQuébec CityQCCanada

Mesenchymal stem cells(MSCs)are multipotent adult stem cells of mesodermal origin that can be isolated from various tissues,including bone marrow,tooth pulp,adipose tissue,and umbilical *** have gained significant attention in regenerative medicine due to their ability to modulate the immune system and favor tissue *** enrich the medium in which they are cultivated with a broad range of bioactive molecules,including growth factors,cytokines,chemokines,enzymes,nucleic acids,and extracellular vesicles that collectively compose the MSC *** increasing number of pre-clinical studies suggest that delivering in vivo an MSC-conditioned medium(i.e.,the medium collected from MSC cultures after at least 3 days of exposure)exerts neuroprotective and anti-inflammatory effects in a variety of neurological conditions.

关键词： protective clinical collective