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Bound in continuum states and induced transparency in mesoscopic demultiplexer with two outputs

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Chinese Physics B 2020年第12期29卷 429-437页

作者： Z Labdouti T mrabti A mouadili E h El Boudouti F Fethi B Djafari-rouhani LPmR Dèpartement de PhysiqueFacultèdes SciencesUniversitèMohammed IOujdaMorocco LSTA Dèpartement de PhysiqueFacultèPolydisciplinaire de LaracheUniversitèAbdelmalek EssaadiTètouanMorocco LPmCER Dèpartement de PhysiqueFacultèdes Sciences et Techniques de MohammediaUniversitèHassan IICasablancaMorocco IEmN UMR CNRS 8520UFR de PhysiqueUniversitède Lille59655 Villeneuve d'AscqFrance

We investigate the electronic transport in a simple mesoscopic cross structure made of two wires(stubs)grafted at the same point along a quantum *** show that the structure may exhibit important phenomena such as bound in continuum(BIC)*** states are transformed into electromagnetically induced transparency(EIT)resonance by detuning slightly the lengths of the *** last phenomenon is used to propose and study a mesoscopic demultiplexer device with an input waveguide and two output *** give closed-form expressions of the geometrical parameters that allow a selective transfer of a given state in the first waveguide without perturbing the second *** effect of temperature on the transmission resonances is also examined by using Landauer-Büttiker *** analytical results of the dispersion relation and transmission and reflection coefficient are obtained using the Green's function method.

关键词： mesoscopic structure demultiplexer device bound states in continuum(BIC) EIT resonance

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

magnetohydrodynamic Activity During Limiter Biasing on the CT-6B Tokamak

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Chinese Physics Letters 2001年第3期18卷 393-395页

作者： KhORShID Pejman WANG Long YANG Xuan-Zong FENG Chun-hua ZhANG Peng-Yun QI Xia-Zhi rouhani Shahriar RAhImITABAR m.Reza AGhAmIR m.Farzin GhORANNEVISS mahmud hANTEZADEh m.Reza Institute of Physics Chinese Academy of SciencesBeijing 100080 Plasma Physics Research Centre Azad UniversityTehranIran Institute for Studies in Theoretical Physics and mathematics TehranIran

magnetohydrodynamic phenomena in the CT-6B Tokamak based on mirnov oscillations have been investigated by applying the limiter biasing potentials and changing the vacuum chamber gas pressure and plasma *** results show that setting up a radial electric field at the plasma edge could drive electromagnetic instabilities in the tokamak *** oscillation frequency upon application of a positive bias decreases about 10-15%and then after a delay time,τ_(d)=2.5-3 ms increases about 20-25%with respect to their value without *** the negative bias regime the oscillation frequency increases about 10%in 1 ms after the application of the bias *** poloidal rotation velocity changes during two steps are related to its link with the radial electric field and the time scale of the density *** frequency of oscillations increases with the increasing chamber gas pressure and decreases with the increasing the outward plasma displacement.

关键词： Tokamak oscillation tokamak

Free vibration and buckling analysis of polymeric composite beams reinforced by functionally graded bamboo fbers

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Applied mathematics and mechanics(English Edition) 2024年第3期45卷 543-562页

作者： h.m.FEIZABAD m.h.YAS Department of mechanical Engineering Razi UniversityKermanshah ***Iran

Natural fibers have been extensively researched as reinforcement materials in polymers on account of their environmental and economic advantages in comparison with synthetic fibers in the recent *** fibers are renowned for their good mechanical properties,abundance,and short cycle *** beams are one of the fundamental structural components and are susceptible to mechanical loads in engineering applications,this paper performs a study on the free vibration and buckling responses of bamboo fiber reinforced composite(BFRC)beams on the elastic *** different functionally graded(FG)layouts and a uniform one are the considered distributions for unidirectional long bamboo fibers across the *** elastic properties of the composite are determined with the law of *** hamilton’s principle,the governing equations of motion are *** generalized differential quadrature method(GDQm)is then applied to the equations to obtain the *** achieved outcomes exhibit that the natural frequency and buckling load values vary as the fiber volume fractions and distributions,elastic foundation stiffness values,and boundary conditions(BCs)and slenderness ratio of the beam ***,a comparative study is conducted between the derived analysis outcomes for BFRC and homogenous polymer beams to examine the effectiveness of bamboo fibers as reinforcement materials,demonstrating the significant enhancements in both vibration and buckling responses,with the exception of natural frequencies for cantilever beams on the Pasternak foundation with the FG-◇fiber ***,the obtained analysis results of BFRC beams are also compared with those for carbon nanotube reinforced composite(CNTRC)beams found in the literature,indicating that the buckling loads and natural frequencies of BFRC beams are lower than those of CNTRC beams.

关键词： bamboo fiber free vibration buckling analysis functionally graded(FG)beam elastic foundation generalized differential quadrature method(GDQm)

Analytical model for thermal lensing and spherical aberration in diode side-pumped Nd:YAG laser rod having Gaussian pump profile

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Chinese Physics B 2015年第12期24卷 334-341页

作者： m h moghtader Dindarlu m Kavosh Tehrani h Saghafifar A maleki Institute of Optics and Laser Malek-Ashtar University of Technology

In this paper, according to the temperature and strain distribution obtained by considering the Gaussian pump profile and dependence of physical properties on temperature, we derive an analytical model for refractive index variations of the diode side-pumped Nd：YAG laser rod. Then we evaluate this model by numerical solution and our maximum relative errors are 5% and 10% for variations caused by thermo–optical and thermo–mechanical effects; respectively. Finally, we present an analytical model for calculating the focal length of the thermal lens and spherical aberration. This model is evaluated by experimental results.

关键词： side-pumped laser rod Gaussian pump profile thermal effects thermal lens spherical aberration

microstructure evolution of a recycled Al-Fe-Si-Cu alloy processed by tube channel pressing

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International Journal of minerals,metallurgy and materials 2018年第10期25卷 1166-1172页

作者： m.h.Farshidi m.Rifai h.miyamoto Department of materials Science and metallurgical Engineering Ferdowsi University of Mashhad Department of mechanical Engineering Doshisha University

Although excellent recyclability is one of the advantages of Al alloys, a recycling process can reduce different properties of these alloys by adding coarse AlFeSi particles into the alloys' microstructures. One of the well-known methods for modifying the microstructure of metallic materials is the imposition of severe plastic deformation(SPD). Nevertheless, the microstructure evolutions of recycled Al alloys containing extraordinary fractions of AlFeSi particles during SPD processing have seldom been considered. The aim of the present work is to study the microstructure evolution of a recycled Al–Fe–Si–Cu alloy during SPD processing. For this purpose, tubular specimens of the mentioned alloy were subjected to different numbers of passes of a recently developed SPD process called tube channel pressing(TCP); their microstructures were then studied using different techniques. The results show that coarse AlFeSi particles are fragmented into finer particles after processing by TCP. however, decomposition and dissolution of AlFeSi particles through TCP processing are negligible. In addition, TCP processing results in an increase in hardness of the alloy, which is attributed to the refinement of grains, to an increase of the dislocation density, and to the fragmentation of AlFeSi particles.

关键词： AlFeSi intermetallic particle severe plastic deformation microstructure tube channel pressing

Solvability of a class of PT-symmetric non-hermitian hamiltonians：Bethe ansatz method

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Chinese Physics B 2017年第6期26卷 14-21页

作者： m Baradaran h Panahi Department of Physics University of Guilan Rasht 41635-1914Iran

We use the Bethe ansatz method to investigate the Schrdinger equation for a class of PT-symmetric non-hermitian hamiltonians. Elementary exact solutions for the eigenvalues and the corresponding wave functions are obtained in terms of the roots of a set of algebraic equations. Also, it is shown that the problems possess sl（2） hidden symmetry and then the exact solutions of the problems are obtained by employing the representation theory of sl（2） Lie algebra. It is found that the results of the two methods are the same.

关键词： PT-symmetry Bethe ansatz method Lie algebraic approach quasi-exactly solvable

A STABILITY ThEOREm FOR CONSTRAINED OPTImAL CONTROL PROBLEmS

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Journal of Computational mathematics 2004年第5期22卷 633-640页

作者： m.h.Farag DepartmentofmathematicsandComputerScienceFacultyofEducation lbriSultanateofOman

This paper presents the stability of difference approximations of an optimal control problem for a quasilinear parabolic equation with controls in the coefficients, boundary conditions and additional restrictions. The optimal control problem has been convered to one of the optimization problem using a penalty function technique. The difference approximations problem for the considered problem is obtained. The estimations of stability of the solution of difference approximations problem are proved. The stability estimation of the solution of difference approximations problem by the controls is obtained.

关键词： Finite difference method Penalty function methods Quasilinear Parabolic equations Stability estimations

Influence of Zn^(2+)or Cu^(2+) on Reduction and Recalcination Behavior of Fe_2TiO_5

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Journal of materials Science & Technology 2007年第5期23卷 697-702页

作者： m.Bahgat m.h.Khedr h.S.Abdelmaksoud CmRDI P.O.Box 87-HelwanCairoEgypt Chemistry Department Faculty of ScienceBenisuef UniversityEgypt

Fe2O3, TiO2, CuO and ZnO powders were mixed according to the formula of （1-x）TiO2 xCuO-Fe2O3 or （1-x）TiO2 xZnO-Fe2O3 （x=0, 0.2 0.4, 0.6, 0.8, 1）, and well ball-milled with h2O for 3 h to ensure homogeneity of the powdered solids, then fired at 1200℃ for 4 h. The fired samples were reduced at 500℃ with hydrogen gas. The reduced samples were subjected to recalcination at 500℃ in CO2 atmosphere. Both of fired, reduced and calcined samples were characterized by X-ray diffraction, vibrating sample magnetometry, reflected light microscopy and scanning electron microscopy. Different phases were formed after firing of Cu^＋2 or Zn^2＋ substituted Fe2TiO5. magnetization （Bs） of the formed phases after firing are very low corresponding to diluted magnetic semiconductors （DmS） and increases with increasing the substituted cations （Cu^＋2 or Zn^2＋）. The reduction of the fired samples enhanced the Bs values whereas the reducibility increases with increasing the Cu^＋2 or Zn^2＋ content. Samples show different tendency toward CO2 decomposition which is very important for environmental minimization for CO2.

关键词： Nanosized ferrite Titanate Reduction magnetic properties Reduction-recalcin-ation CO2 decomposition