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Creation and research of the SAW transducer with a single-phase grid and a piezoelectric zinc oxide film

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Journal of Advanced Dielectrics 2022年第5期12卷 48-52页

作者： G.Ya.Karapetyan m.e.Kutepov e.m.kaidashev A.L.Nikolaev Laboratory of Nanomaterials Southern Federal University 200/1 Stachki Avenue344090 Rostov-on-DonRussia

A method for obtaining a new type of surface acoustic wave(SAW)transducer operating at double frequency with a single-phase closed-loop lattice and a piezoelectric zinc oxide film is developed and experimentally investigated.A method for calculating such a transducer has been developed,its equivalent circuit has been compiled,taking into account propagation losses,losses in the metal film and the inductance of the connecting *** the frequency is doubled,the SAW attenuation per unit length increases.

关键词： Surface acoustic wave(SAW) interdigital transducer(IDT) zinc oxide(ZnO)film.

Synthesis of ZnO nanorods for piezoelectric resonators and sensors

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Journal of Advanced Dielectrics 2022年第1期12卷 24-30页

作者： A.L.Nikolaev m.A.Kazmina N.V.Lyanguzov K.G.Abdulvakhidov e.m.kaidashev Research and education Center“materials”Don State Technical University No.1 Gagarin sq. Rostov-on-Don344000Russia Vorovich mathematics mechanics and Computer Sciences Institute Southern Federal University No.200/1 Stachki Str.Rostov-on-Don 344090Russia Southern Research Center RAS No.41 Chehova Str.Rostov-on-Don344006Russia The Smart materials Research Institute Southern Federal University No.178/24 Sladkova Str.Rostov-on-Don 344090Russia

efficiency of the piezoelectric chemisensors may be considerably enhanced by use of zinc oxide nanorods as sensing *** nanorod arrays being good piezoelectric materials possess large surface area,which provides extra benefits for chemisorption and *** oriented nanorod arrays are typically prepared onto highly crystalline substrates,whereas the nanorods growth onto metal contacts meets significant technological *** this paper,we report on carbothermal,electrochemical,and hydrothermal techniques of ZnO nanorod arrays synthesis on metal *** optical and structural properties of the obtained nanorods were studied using scanning electron microscopy,X-ray diffraction(XRD),Raman spectroscopy,and lumi-nescence spectroscopy.A reliable technique was developed for obtaining ohmic contact with the grown nanorods.I-U curves of prepared contact were *** synthesis made it possible to obtain the most crystallinely perfect,homogeneous,and dense arrays of nanorods and control the concentration of point defects by changing the synthesis parameters over a wide *** electrochemical synthesis demonstrated excellent results for synthesis of ZnO nanorods on the surface of resonator electrodes.

关键词： Hydrothermal synthesis electrochemical synthesis carbothermal synthesis upper contact ZnO nanorods

Optimizing VO_(2)film properties for use in SAW devices

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Journal of Advanced Dielectrics 2021年第5期11卷 44-47页

作者： m.e.Kutepov G.Ya.Karapetyan I.V.Lisnevskaya K.G.Abdulvakhidov A.A.Kozmin e.m.kaidashev Laboratory of Nanomaterials Southern Federal University Stachki200/1344090 Rostov-on-DonRussia Department of Chemistry Southern Federal University Zorge7344090Rostov-on-DonRussia Smart materials Research Institute Southern Federal University Sladkova178/24344090Rostov-on-DonRussia

The aim of this study is to optimize the conditions for producing thin VO_(2)films for their use in SAW *** used the pulsed laser deposition(PLD)method to produce VO_(2)*** used a metallic vanadium *** dependence of the oxygen pressure during PLD on the resistive metal-insulator transition(mIT)on substrates of c-sapphire and LiNbO_(3)YX/128°was *** resulting films had sharp metal-insulator temperature transitions on c-Al_(2)O_(3).The most high-quality films showed resistance change by four orders of *** the lower point of the hysteresis,the resistance of these samples was in the range of 50-100Ω.The synthesized VO_(2)films had a sharp temperature transition and a relatively small width of thermal *** SAW damping during its passage through a VO_(2)/ZnO/LiNbO_(3)YX/128°film at the metal-insulator phase transition temperature was *** SAW decreases with increasing temperature from 52 dB/cm to 0 dB/cm.

关键词： Surface acoustic wave VO_(2)film laser pulsed deposition parameter S21 metal-insulator transition

embedding epitaxial VO_(2)film with quality metal-insulator transition to SAW devices

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Journal of Advanced Dielectrics 2022年第5期12卷 53-59页

作者： m.e.Kutepov §,G.Ya.Karapetyan T.A.minasyan V.e.Kaydashev I.V.Lisnevskaya K.G.Abdulvakhidov A.A.Kozmin e.m.kaidashev Laboratory of Nanomaterials Southern Federal University200/1 Stachki Ave.344090 Rostov-on-DonRussia Department of Chemistry Southern Federal University7 Zorge St.344090 Rostov-on-DonRussia Smart materials Research Institute Southern Federal University178/24 Sladkova St.344090 Rostov-on-DonRussia

epitaxial VO_(2)films grown by pulsed laser deposition(PLD)method with superior phase transition related switching characteristics are successfully embedded to SAW devices using concept of the“impedance loaded SAW sensor”.A resistance of VO2 sensor abruptly drops from 0.7 mΩto 90Ωwhen it is heated above~65℃and shows a narrow hysteresis loops when *** designs of SAW devices are examined in which RF signal is reflected back from interdigital transducer(IDT)or a surface acoustic waves(SAW)is transferred through a coupler and the RF response is altered 2 and 3 times correspondingly upon the phase transition in *** the proposed devices with external load,a SAW does not propagate via VO2 film and therefore is not attenuated which is beneficiary for wireless ***,a SAW phase shift as great as 50°is induced to the SAW transferred through the coupler due to the phase transition in *** proposed approach may boost the development of remotely controlled autonomous sensors,including those based on VO2 metamaterials and hybrid plasmonic structures for near IR/middle IR and sub-THz/THz applications.

关键词： Surface acoustic wave SAW pulsed laser deposition PLD VO_(2) epitaxial film.

The sexually dimorphic expression of glutamate transporters and their implication in pain after spinal cord injury

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Neural Regeneration Research 2025年第11期20卷 3317-3329页

作者： Jennifer m.Colón-mercado Aranza I.Torrado-Tapias Iris K.Salgado Jose m.Santiago Samuel e.Ocasio Rivera Dina P.Bracho-Rincon Luis H.Pagan Rivera Jorge D.miranda Department of Physiology University of Puerto RicoMedical Sciences CampusSan JuanPRUSA National Institutes of Health National Human Genome Research InstituteBethesdaMDUSA Universidad Central del Caribe School of MedicineBayamónPRUSA University of Puerto Rico Carolina CampusCarolinaPRUSA Institute of Neurobiology San JuanPRUSA

In addition to the loss of motor function,~60% of patients develop pain after spinal cord *** cellular-molecular mechanisms are not well understood,but the data suggests that plasticity within the rostral,epicenter,and caudal penumbra of the injury site initiates a cellularmolecular interplay that acts as a rewiring mechanism leading to central neuropathic *** can lead to the formation of new connections triggering abnormal sensory *** excitatory glutamate transporters are responsible for the reuptake of extracellular glutamate which makes them a critical target to prevent neuronal hyperexcitability and *** previous studies showed a sexually dimorphic therapeutic window for spinal cord injury after treatment with the selective estrogen receptor modulator *** this study,we investigated the anti-allodynic effects of tamoxifen in male and female rats with spinal cord *** hypothesized that tamoxifen exerts anti-allodynic effects by increasing the expression of glutamate transporters,leading to reduced hyperexcitability of the secondary neuron or by decreasing aberrant *** and female rats received a moderate contusion to the thoracic spinal cord followed by subcutaneous slow-release treatment of tamoxifen or matrix pellets as a control(placebo).We used von Frey monofilaments and the“up-down method”to evaluate mechanical *** treatment decreased allodynia only in female rats with spinal cord injury revealing a sexdependent *** expression profile of glutamatergic transporters(excitatory amino acid transporter 1/glutamate aspartate transporter and excitatory amino acid transporter 2/glutamate transporter-1)revealed a sexual dimorphism in the rostral,epicenter,and caudal areas of the spinal cord with a pattern of expression primarily on *** rodents showed a significantly higher level of excitatory amino acid transporter-1 expression while male rodents showed increased

关键词： allodynia central neuropathic pain eAAT-1/GLAST eAAT-2/GLT-1 glutamate transporters selective estrogen receptor modulator sexual dimorphism spinal cord injury trauma

Impact of Zika virus non-structural protein mutations on hippocampal damage

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Neural Regeneration Research 2025年第8期20卷 2307-2308页

作者： Larissa m.G.Cassiano Roney S.Coimbra Neurogenômica/Imunopatologia Instituto RenéRachouFiocruzBelo HorizonteBrazil Departamento de Bioquímica e Imunologia Instituto de Ciências BiológicasUniversidade Federal de Minas GeraisBelo HorizonteBrazil

The Zika virus(ZIKV),a member of the Flaviviridae family,attracted worldwide attention for its connection to severe neurological effects,notably microcephaly in newborns,first reported during the 2015 epidemic in ***,its impact goes beyond fetal and neonatal abnormalities,also affecting the central nervous system(CNS)in both children and adults,leading to enduring cognitive and behavioral impairments.

关键词： damage fetal neonatal

environmental chemical study on the marsh of Fatimid cemetery at Aswan City, egypt

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Journal of environmental Sciences 2002年第4期14卷 464-473页

作者： m.e.Soltan Chemistry Department Faculty of Science

environmental chemical study were carried out on the Fatimid cemetery marsh at Aswan City(24°1'N and 32°9'e), egypt. marsh contents(warter, soil, sediment, metal and nonmetal bearing salts, and emergent weed) were analysed to known the source of marsh water, speciation of the different elements between the marsh contents, and the toleration of emergent weed (Phargmites australies) for different metals and their bioaccumulation coefficients. Thus, metals(Ca, mg, Na, K, Ni, Fe, mn, Cu, Zn, Cd and Pb) and nonmetals(CO 2- 3, HCO - 3, Cl -, SO 2- 4, PO 3- 4, NO - 3, SiO 2, organic matter and pH value) were determined in the samples. According to the chemical analysis, and applying the base exchange equation(water type) and calculate the hydrochemical parameters for marsh water samples, we can indicate that the marsh water is ground water with Na SO 4 type and deep meteoric genesis. Topsoil of marsh dry land characterized by CaCl as dominant salt,while NaCl is a dominant salt in subsoil. The elevated pH values of marsh contents minimized the metal solubilities in different samples. Phragmites australies showed a strong ability to accumulate mn and Fe in the aerial part in opposite to Co, Ni and Cd.

关键词： marsh water soil sediment emergent weed egypt

INVeRSe PROBLemS FOR A GeNeRAL mULTI-CONNeCTeD BOUNDeD DRUm WITH APPLICATIONS IN PHYSICS

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Acta mathematica Scientia 2003年第1期23卷 104-116页

作者： e.m.e.Zayed mathematics Department Faculty of Science Zagazig University Zagazig Egypt

This paper studies the influence of a finite container on an ideal *** trace of the heat kernel (t) =exp, where are the eigenvalues of the negative Laplacian -in Rn(n = 2 or 3), is studied for a general multi-connected bounded drum ft which is surrounded by simply connected bounded domains Ωi with smooth boundaries Ωi(i = 1,… ,m) where the Dirichlet, Neumann and Robin boundary conditions on Ωi(i = 1,…,m) are considered. Some geometrical properties of Ω are determined. The thermodynamic quantities for an ideal gas enclosed in Ω are examined by using the asymptotic expansions of (t) for short-time t. It is shown that the ideal gas can not feel the shape of its container Ω, although it can feel some geometrical properties of it.

关键词： Inverse problem heat kernel eigenvalues an ideal gas multi-connected bounded domain

The 3D Inverse Problem of the Wave equation for a General multi-connected Vibrating membrane with a Finite Number of Piecewise Smooth Boundary Conditions

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Acta mathematica Sinica,english Series 2005年第4期21卷 733-752页

作者： e.m.e.ZAYeD mathematics Department Faculty of ScienceZagazig UniversityZagazig.Egypt

The trace of the wave kernel μ（t） =∑ω=1^∞ exp（-iteω^1/2）, where {eω}ω^∞=1 are the eigenvalues of the negative Laplacian -△↓2 = -∑k^3=1 （δ/δxk）^2 in the （x^1, x^2, x^3）-space, is studied for a variety of bounded domains, where -∞ 〈 t 〈 ∞ and i= √-1. The dependence of μ （t） on the connectivity of bounded domains and the Dirichlet, Neumann and Robin boundary conditions are analyzed. Particular attention is given for a multi-connected vibrating membrane Ω in Ra surrounded by simply connected bounded domains Ω j with smooth bounding surfaces S j （j = 1,……, n）, where a finite number of piecewise smooth Dirichlet, Neumann and Robin boundary conditions on the piecewise smooth components Si^＊（i = 1 ＋ kj-1,……, kj） of the bounding surfaces S j are considered, such that S j = Ui-1＋kj-1^kj Si^＊, where k0=0. The basic problem is to extract information on the geometry Ω by using the wave equation approach from a complete knowledge of its eigenvalues. Some geometrical quantities of Ω （e.g. the volume, the surface area, the mean curvuture and the Gaussian curvature） are determined from the asymptotic expansion ofexpansion of μ（t） for small │t│.

关键词： Inverse problem Wave kernal eigenvalues Greens function multi-connected vibrating membrane Negative Laplacian Heat kernel