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Analysis of Landau damping in radially inhomogeneous plasma column

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Chinese Physics B 2018年第5期27卷 365-373页

作者： h Rajabalinia-Jelodar m K Salem F m Aghamir h Zakeri-Khatir Plasma Physics Research Center Science and Research BranchIslamic Azad University Department of Physics University of Tehran

The Landau damping behavior in a cylindrical inhomogeneous warm magnetized plasma waveguide has been *** radial inhomogeneity for different characteristic lengths（L0） with strong spatial dispersion has been taken into *** analyses have been considered for two limits ωce 〈 ωpe and ωce 〉 ωpe. Due to the radial inhomogeneity of the plasma, all essential equations for studying the Landau damping are calculated in the Bessel–Furrier and differential Bessel–Furrier expansions. The dependence of Landau damping on the inhomogeneity, temperature and external magnetic field for electrostatic modes is scrutinized and described in detail through numerical calculations. The associated numerical results are presented and discussed.

关键词： inhomogeneous warm plasma cylindrical plasma waveguide Landau damping electrostatic modes

Effect of partition coefficient on microsegregation during solidification of aluminium alloys

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International Journal of minerals,metallurgy and materials 2014年第10期21卷 980-989页

作者： m.h.Avazkonandeh-Gharavol m.haddad-Sabzevar h.Fredriksson Department of metallurgy and materials Engineering Faculty of Engineering Ferdowsi University of Mashhad Department of materials Science and Engineering School of Industrial Engineering and Management Royal Institute of Technology

In the modeling of microsegregation, the partition coefficient is usually calculated using data from the equilibrium phase diagrams. The aim of this study was to experimentally and theoretically analyze the partition coefficient in binary aluminum--copper alloys. The sam- ples were analyzed by differential thermal analysis （DTA）, which were melted and quenched from different temperatures during solidifica- tion. The mass fraction and composition of phases were measured by image processing and scanning electron microscopy （SEm） equipped with an energy-dispersive X-ray spectroscopy （EDS） unit. These data were used to calculate as the experimental partition coefficients with four different methods. The experimental and equilibrium partition coefficients were used to model the concentration profile in the primary phase. The modeling results show that the profiles calculated by the experimental partition coefficients are more consistent with the experi- mental profiles, compared to those calculated using the equilibrium partition coefficients.

关键词： aluminum copper alloys solidification partition coefficient microsegregation numerical modeling differential thermal analysis

The electrical impedance, AC conductivity and dielectric properties of phenol red compound investigated and modeled by an artificial neural network

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Communications in Theoretical Physics 2020年第10期72卷 139-148页

作者： h A m Ali D m habashy Physics Department Faculty of EducationAin Shams UniversityRoxyCairo 11757Egypt

The impedance spectroscopy,electrical conductivity and electric modulus of bulk phenol red were measured,as a function of both frequency and *** neural networks(ANNs)were used for modeling its electrical *** two parts(real and imaginary)of its complex impedance(Z^*)were analyzed and the activation energy related to the electrical relaxation process was *** curves were plotted showing semicircles for the different *** AC electrical conductivity follows a power lawσac(ω)αω^η.The maximum barrier height Bm was derived for specific temperatures.A plausible mechanism for the AC conduction of bulk phenol red was deduced from the temperature reliance of the frequency *** dielectric data was analyzed using electric modulus as a *** addition,ANNs were used to model the impedance parts and the total electrical *** runs were tried,to obtain the best *** training and prediction results were compared to the equivalent experimental results,with a good match *** equation describing the experimental results was obtained mathematically,based on the use of *** outputs demonstrated that ANNs are an admirable tool for modeling experimental results.

关键词： phenol red impedance spectroscopy electric modulus neural network

Petrology, geochemistry, radioactivity, and m–W type rare earth element tetrads of El Sela altered granites, south eastern desert,Egypt

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Acta Geochimica 2019年第1期38卷 95-119页

作者： A.m.El mezayen m.A.heikal m.G.El-Feky h.A.Shahin I.K.Abu Zeid S.R.Lasheen Geology Department Faculty of Science Al Azhar University Nuclear material Authority

The southern part of the Eastern Desert of Egypt—about 30 km southwest of Abu-Ramad city—is mainly covered by ophiolitic rocks(Sul hamed), island arc assemblage, younger granites(muscovite granites of Qash Amer and two mica granites of El Sela), and various acidic and basic dikes. Field, petrological, and geochemical studies indicate that the El Sela shear zone has been subject to hydrothermal and supergene alteration such as kaolinization, albitization, sericitization, and hematitization. It is invaded by quartz ENE–WSW veins associated with hydrothermal alteration accompanied by radioactive mineralization. The investigated younger granitic rocks had very low contents of compatible elements, such as Cr, Ni,and Co; and high contents of incompatible elements, such as Zr, and large ion lithophiles, such as Sr, especially in the El Sela shear zone. major oxide and trace element analyses revealed calc-alkaline affinity and peraluminous *** highly differentiated granitic rocks' lower Zr/hf and higher Y/ho than the normal ratio are consistent with hydrothermal alteration. most samples had rare earth element(REE)-patterns with an m-type tetrad effect in the first and fourth segments and a W-type tetrad in the third segment. The average ∑REE in the studied granites was lower than the world granite average; the ratio of light to heavy REEs greater. The main radioactive, uranium-bearing, and uraniferous Fe and mn minerals are uranothorite,autunite, uranophane and autunite as compounds, kasolite,columbite, xenotime, uranophane-bearing zircon and jarosite, silver-bearing pyrite, hematite, and autunite-bearing pyrolusite.

关键词： Geochemistry REE-tetrad effect Radioactive minerals Radiometric measurements Qash Amer El Sela

Effect of substrate temperature on the morphological,structural,and optical properties of RF sputtered Ge(1-x)Snx films on Si substrate

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Chinese Physics B 2017年第5期26卷 313-318页

作者： h mahmodi m R hashim Nano-Optoelectronics Research Laboratory School of Physics Universiti Sains Malaysia 11800 USM Pulau Penang Malaysia Institute of Nano Optoelectronics Research and Technology (INOR) Universiti Sains Malaysia 11800 USM Pulau Penang Malaysia

In this study, Ge（1-x）Snx alloy films are co-sputtered on Si（100） substrates using RF magnetron sputtering at different substrate temperatures. Scanning electron micrographs, atomic force microscopy（AFm）, Raman spectroscopy, and x-ray photoemission spectroscopy（XPS） are conducted to investigate the effect of substrate temperature on the structural and optical properties of grown Ge Sn alloy films. AFm results show that RmS surface roughness of the films increases from 1.02 to 2.30 nm when raising the substrate temperature. This increase could be due to Sn surface segregation that occurs when raising the substrate temperature. Raman spectra exhibits the lowest FWhm value and highest phonon intensity for a film sputtered at 140℃. The spectra show that decreasing the deposition temperature to 140℃ improves the crystalline quality of the alloy films and increases nanocrystalline phase formation. The results of Raman spectra and XPS confirm Ge–Sn bond formation. The optoelectronic characteristics of fabricated metal-semiconductor-metal photodetectors on sputtered samples at room temperature（RT） and 140℃ are studied in the dark and under illumination. The sample sputtered at 140℃ performs better than the RT sputtered sample.

关键词： sputtering magnetron illumination crystalline raising roughness optoelectronic phonon segregation FWhm

Dynamic modeling of a three-dimensional braided composite thin plate considering braiding directions

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Applied mathematics and mechanics(English Edition) 2025年第1期46卷 123-138页

作者： Chentong GAO huiyu SUN Jianping GU W.m.hUANG College of Aerospace Engineering Nanjing University of Aeronautics and Astronautics School of mechanical and Aerospace Engineering Nanyang Technological University Jiangsu Key Laboratory of Advanced Structural materials and Application Technology School of Materials Science and EngineeringNanjing Institute of Technology

Currently, there are a limited number of dynamic models available for braided composite plates with large overall motions, despite the incorporation of three-dimensional(3D) braided composites into rotating blade components. In this paper, a dynamic model of 3D 4-directional braided composite thin plates considering braiding directions is established. Based on Kirchhoff's plate assumptions, the displacement variables of the plate are expressed. By incorporating the braiding directions into the constitutive equation of the braided composites, the dynamic model of the plate considering braiding directions is obtained. The effects of the speeds, braiding directions, and braided angles on the responses of the plate with fixed-axis rotation and translational motion, respectively, are investigated. This paper presents a dynamic theory for calculating the deformation of 3D braided composite structures undergoing both translational and rotational motions. It also provides a simulation method for investigating the dynamic behavior of non-isotropic material plates in various applications.

关键词： three-dimensional (3D) braided composite braiding direction composite thin plate large overall motion dynamic model O313.7

mφller Energy-momentum Complex in General Relativity for higher Dimensional Universes

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Chinese Physics Letters 2007年第7期24卷 1821-1824页

作者： m. Aygiin S. Aygiin i. Yflmaz h. Baysal i. Tarhan Department of Physics Art and Science Faculty Canakkale Onsekiz Mart University 17020 Canakkale Thrkey Department of Secondary Science and mathematics Education Faculty of Education~anakkale Onsekiz Mart University 17100 Canakkale Turkey

Using the mφ11er energy-momentum definition in general relativity （GR） we calculate the total energy-momentum distribution associated with （n 4- 2）-dimensional homogeneous and isotropic model of the universe. It is found that total energy of m^ller is vanishing in （n 4- 2） dimensions everywhere but n-momentum components of mφ11er in （n 4- 2） dimensions are different from zero. Also, we evaluate the static Einstein Universe, FRW universe and de Sitter universe in four dimensions by using （n 4- 2）-type metric, then calculate the mφ11er energy-momentum distribution of these spacetimes. however, our results are consistent with the results of Banerjee and Sen, Xulu, Radinschi, Vargas, Cooperstock-Israelit, A ygiin et al., Rosen, and Johri et al. in four dimensions.

关键词： Energy-momentum Relativity Dimensional

Electrical,thermal and electrochemical properties of γ-ray-reduced graphene oxide

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International Journal of minerals,metallurgy and materials 2021年第10期28卷 1726-1734页

作者： m.m.Atta h.A.Ashry G.m.Nasr h.A.Abd El-Rehim Radiation Physics Department National Center for Radiation Research and Technology(NCRRT)Atomic Energy AuthorityCairo 11787Egypt Physics Department Faculty of ScienceCairo UniversityCairo 12613Egypt Radiation Chemistry Department National Center for Radiation Research and Technology(NCRRT)Atomic Energy AuthorityCairo 11787Egypt

The properties of γ-ray-reduced graphene oxide samples(GRGOs)were compared with those of hydrazine hydrate-reduced graphene oxide(hRGO).Fourier transform infrared spectroscopy,X-ray diffractometry,Raman spectroscopy,Brunauer-Emmett-Teller surface area analysis,thermogravimetric analysis,electrometry,and cyclic voltammetry were carried out to verify the reduction process,structural changes,and defects of the samples,as well as to measure their thermal,electrical,and electrochemical *** with γ-rays distorted the structure of GRGOs and generated massive defects through the extensive formation of new smaller sp^(2)-hybridized domains compared with those of *** thermal stability of GRGOs was higher than that of hRGO,indicating the highly efficient removal of thermally-labile oxygen species by γ-*** prepared at 80 kGy showed a pseudocapacitive behavior comparable with the electrical double-layer capacitance behavior of ***,the specific capacitance of GRGO was enhanced by nearly three times compared with that of *** results reflect the advantages of radiation reduction in energy storage applications.

关键词： graphene γ-ray electrical thermal electrochemical

Emerging role of A-kinase anchoring protein 5 signaling in reward circuit function

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Neural Regeneration Research 2025年第10期20卷 2913-2914页

作者： William J.Flerlage mark L.Dell’Acqua Brian m.Cox Fereshteh S.Nugent Uniformed Services University of the health Sciences Department of Pharmacology and Molecular TherapeuticsBethesdaMDUSA Department of Pharmacology University of Colorado School of MedicineAnschutz Medical CampusAuroraCOUSA

There is a strong evidence supporting the hypothesis of synaptic dysfunction as a major contributor to neural circuit and network disruption underlying emotional and mood dysregulation in psychiatric disorders(Simmons et al.,2024).Diverse sets of distinct molecular signaling pathways converge on the synapse to regulate synaptogenesis,synaptic function,and synaptic plasticity in brain regions and circuits through complex interactions organized by numerous multivalent protein scaffolds,including the family of proteins known as A-kinase anchoring proteins(AKAPs).

关键词： function supporting