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Free vibration and transient response of double curved beams connected by intermediate straight beams

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Applied Mathematics and Mechanics(English Edition) 2025年第1期46卷 37-62页

作者： R.A.JAFARI-TALOOKOLAEI h.GhANDVAR E.JUMAEV s.KhATIR T.CUONG-LE school of Mechanical Engineering Babol Noshirvani University of Technology Department of Mechanical Engineering Faculty of Engineering New Uzbekistan University University of Business and science Center for Engineering Application and Technology solutions Ho Chi Minh City Open University

This paper investigates the free vibration and transient response of interconnected structures including double curved beams and intermediate straight beams,which are all constructed from functionally graded porous(FGP) materials. The strain potential and kinetic energies of each beam along with the work done by the external force are calculated. Additionally, a higher-order beam element is introduced to derive stiffness and mass matrices, along with the force vector. The curved and straight beams are discretized, and their assembled stiffness, mass matrices, and force vectors, are *** conditions at the joints are used to derive the total matrices of the entire structure. subsequently, the natural frequencies and transient response of the system are determined. The accuracy of the mathematical model and the self-developed computer program is validated through the comparison of the obtained results with those of the existing literature and commercial software ANsYs, demonstrating excellent ***, a comprehensive study is conducted to investigate the effects of various parameters on the free vibration and transient response of the considered structure.

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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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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

Benevolent behavior of Kleinia grandiflora leaf extract as a green corrosion inhibitor for mild steel in sulfuric acid solution

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International Journal of Minerals,Metallurgy and Materials 2014年第11期21卷 1083-1095页

作者： Muthukrishnan Pitchaipillai karthik Raj Jeyaprabha Balasubramanian Prakash Periakaruppan Department of Chemistry Faculty of Engineering Karpagam UniversityCoimbatore-641021 Tamil Nadu India Department of Chemistry Thiagarajar CollegeMadurai-625009 Tamil Nadu India Department of Civil Engineering Fatima Michael College of Engineering & TechnologyMadurai-625020 Tamil Nadu India

The ethanolic extract of Kleinia grandiflora leaves was characterized and tested for its potential anticorrosion properties on mild steel in 1 M h2sO4 medium using mass-loss analysis, potentiodynamic polarization measurements, electrochemical impedance spectroscopy, Fourier-transform infrared spectroscopy, scanning electron microscopy, UV–visible spectroscopy, and X-ray diffraction analysis. The effect of temperature on the corrosion behavior of mild steel was studied in the range of 308 to 328 K. The inhibition efficiency was observed to increase with increasing concentration of the extract. Polarization curves revealed that the Kleinia grandiflora leaf extract is a mixed inhibitor. Impedance diagrams revealed that an increase of Kleinia grandiflora leaf extract concentration increased the charge transfer resistance and decreased the double-layer capacitance. The adsorption process obeys Langmuir＇s model, with a standard free energy of adsorption（ΔGads） of-18.62 k J/mol. The obtained results indicate that the Kleinia grandiflora leaf extract can serve as an effective inhibitor for the corrosion of mild steel in a sulfuric acid medium.

关键词： steel corrosion mild steel sulfuric acid corrosion inhibitors

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

Investigation of structural,magnetic and optical properties of rare earth substituted bismuth ferrite

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Journal of Rare Earths 2013年第4期31卷 370-375页

作者： T.Durga Rao T.karthik saket Asthana Advanced Functional Materials Laboratory Department of PhysicsIndian Institute of Technology Hyderabad Department of Materials science and Engineering Indian Institute of Technology Hyderabad

Polycrystalline BiFeO3 and rare earth substituted ***3 （BRFO, R=Y, ho and Er） compounds were prepared by rapid solid state sintering technique. structural phase analysis indicated that all the compounds stabilized in rhombohedral structure （R3c space group） and a small orthorhombic phase fraction was observed in BRFO compounds. From the Raman spectra results, the changes in the phonon frequencies （A1） and line widths suggested lattice distortion in the BRFO compounds as was evidenced in the XRD analysis. Compared to the linear variation of magnetization with magnetic field （M-h） shown by BFO, an obvious M-h loop was observed in BRFO compounds which could be due to the suppression of space modulated spin structure and was explained on the basis of weak ferromagnetism and field induced spin reorientation. UV-Vis spectroscopy evidenced a change in local FeO6 envi- ronment due to shift in the 6Alg→4T2g energy transition band. BRFO compounds with improved remnant magnetization and coercive field are applicable for magnetoelectric devices.

关键词： structural distortion spin-reorientation G-type antiferromagnet rare earths

s-Factor of the ^(3)h(α,γ)^(7)Li Reaction at Astrophysical Energies

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Chinese Physics Letters 2013年第10期30卷 59-62页

作者： h.sadeghi Department of Physics Faculty of ScienceArak UniversityArak 8349-8-38156Iran

The astrophysical s-factor forα-^(3)h radiative capture is calculated at astrophysical *** construct conserved two-and three-body electromagnetic currents,using minimal substitution in the explicit momentum dependence of the two-and three-nucleon *** realistic Argonne v_(18) two-nucleon and Urbana IX or Tucson–Melbourne three-nucleon interactions are considered for *** extrapolation of results for the astrophysical s-factor at zero energy,the energy in the order of 1 keV and less is found to be s(0)=0.107(0.112)keV·b,with(without)three-body interactions in satisfactory agreement with other theoretical results and experimental data.

关键词： calculation substitution momentum

Numerical tests of theoretical models describing ionization of h(1s) atom by linearly polarized flat pulse of laser radiation

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Chinese Physics B 2018年第9期27卷 254-261页

作者： Jarostaw h Bauer Min Deng Katedra Fizyki Teoretycznej Wydzial Fizyki i lnformatyki Stosowanej Uniwersytetu LddzkiegoUI.Pomorska 149/153PL-90-236 LddlPoland state Key Laboratory o fLow-Dimensional Quantum Physics Department of PhysicsTsinghua UniversityBeijing 100084China

We derive the well-known Coulomb correction factor for the Gordon-Volkov wave function describing an outgoing electron in the process of ionization in an intense laser field. Although rigorous treatment would limit its use only to laser fields much lower than the so-called barrier-suppression field, it appears that in practice the correction factor may be used also close to and even above this critical value of the laser field. We compare predictions of several analytical expressions describing ionization rate of the hydrogen atom in its ground state in the strong linearly polarized laser field. We also compare ionization probabilities obtained by integrating these ionization rates over a temporal envelope of the laser pulse with predictions based on the exact numerical solution to the time-dependent schr ¨odinger equation.

关键词： laser fields ionization s-matrix Coulomb-Volkov wave function