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First-principles study and electronic structures of Mn-doped ultrathin ZnO nanofilms

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Chinese Physics B 2012年第10期21卷 362-368页

作者： e.Salmani A.Benyoussef h.ez-Zahraouy e.h.saidi O.Mounkachi LMPhe(URAC 12) Departement de PhysiqueFacult'e des SciencesUniversit'e Mohammed V-AgdalRabatMorocco LPhe Departement de PhysiqueFacult'e des SciencesUniversit'e Mohammed V-AgdalRabatMorocco Institute of Nanomaterials and Nanotechnology MAScIRRabatMorocco

The first-principles density functional calculation is used to investigate the electronic structures and magnetic properties of Mn-doped and N-co-doped ZnO *** band structure calculation shows that the band gaps of ZnO films with 2,4,and 6 layers are larger than the band gap of the bulk with wurtzite structure and decrease with the increase of film ***,the four-layer ZnO nanofilms exhibit ferromagnetic phases for Mn concentrations less than 24% and 12% for Mn-doping performed in the whole layers and two layers of the film respectively,while they exhibit spin glass phases for higher Mn *** is also found,on the one hand,that the spin glass phase turns into the ferromagnetic one,with the substitution of nitrogen atoms for oxygen atoms,for nitrogen concentrations higher than 16% and 5% for Mn-doping performed in the whole layers and two layers of the film *** the other hand,the spin-glass state is more stable for ZnO bulk containing 5% of Mn impurities,while the ferromagnetic phase is stable by introducing the p-type carriers into the bulk ***,it is shown that using the effective field theory for ferromagnetic system,the Curie temperature is close to the room temperature for the undamped Ruderman-Kittel-Kasuya-Yoshida（RKKY） interaction.

关键词： ultra thin film ZnO ab initio electronic structure magnetic properties effective field theory

electronic and magnetic structures of V-doped zinc blende Zn_(1-x)V_xN_yO_(1-y) and Zn_(1-x)V_xP_yO_(1-y)

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Chinese Physics B 2011年第8期20卷 419-424页

作者： N.Mamouni M.Belaiche A.Benyoussef A.el Kenz h.ez-Zahraouy M.Loulidi e.h.saidi e.K.hlil Laboratoire de Magntisme et de Physique des hautes energies Dpartement de Physique Associ au CNRSTURACB.P.1014Facult des SciencesRabatMorocco Laboratoire de Magntisme Matriaux MagntiquesMicro-ondes et CramiqueENSRabatMorocco INANOTeCh Institute of Nanomaterials and NanotechnologyMAScIRRabatMorocco Laboratoire de Physique des hautes energies Dpartement de Physique B.P.1014Facult des SciencesRabatMorocco Institut Nel MCMF-UJFC.N.R.SB.P.16638042 Grenoble CedexFrance

electronic and magnetic structures of zinc blende ZnO doped with V impurities are studied by first-principles calculations based on the Korringa-Kohn-Rostoker （KKR） method combined with the coherent potential approximation （CPA）. Calculations for the substitution of O by N or P are performed and the magnetic moment is found to be sensitive to the N or P content. Furthermore, the system exhibits a half-metallic band structure accompanied by the broadening of vanadium bands. The mechanism responsible for ferromagnetism is also discussed and the stability of the ferromagnetic state compared with that of the paramagnetic state is systematically investigated by calculating the total energy difference between them by using supercell method.

关键词： ab initio calculations density of states magnetic moment doping diluted magneticsemiconductors

Artificial perturbation for solving the Korteweg-de Vries equation

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Journal of Zhejiang University-Science A(Applied Physics & engineering) 2006年第12期7卷 2079-2082页

作者： KheLIL N. BeNSALAh N. saidi h. ZeRARKA A. Laboratory of Physics and Applied Mathematics University Med Khider BP 145 07000 Biskra Algeria

A perturbation method is introduced in the context of dynamical system for solving the nonlinear Korteweg-de Vries (KdV) equation. Best efficiency is obtained for few perturbative corrections. It is shown that, the question of convergence of this approach is completely guaranteed here, because a limited number of term included in the series can describe a sufficient exact solution. Comparisons with the solutions of the quintic spline, and finite difference are presented.

关键词： Perturbation Taylor series Quintic spline Korteweg-de Vries (KdV) equation

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

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

Collapse assessment of steel moment frames using endurance time method

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earthquake engineering and engineering Vibration 2015年第2期14卷 347-360页

作者： e.Rahimi h.e.estekanchi Department of Civil engineering Sharif University of Technology (SUT)

In endurance time(eT) method structures are subjected to a set of predesigned intensifying excitations. These excitations are produced in a way that their response spectrum, while complying with a specifi ed spectrum, intensifi es with time so they can be used approximately to simulate the average effects of several ground motions scaled to different intensities. In this paper applicability of the eT method for evaluating collapse potential of buildings is investigated. A set of four steel moment frames is used for collapse assessment. The process of using eT method in collapse evaluation is explained and the results are compared with incremental dynamic analysis(IDA) results. It is shown that although the computational effort using the eT method is much less than the IDA analysis, the results of both methods are consistent. Finally collapse fragility curves using eT and IDA methods are produced and it is shown that the probabilities of collapse in different hazard levels are also consistent.

关键词： endurance time method collapse analysis incrementa

Solution flow rate influence on ZnS thin films properties grown by ultrasonic spray for optoelectronic application

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Journal of Semiconductors 2018年第9期39卷 1-7页

作者： A.Derbali h.saidi A.Attaf h.Benamra A.Bouhdjer N.Attaf h.ezzaouia L.Derbali M.S.Aida Laboratory of Thin Films and Applications LPCMA University of Biskra Algeria BP 145 RP 07000 Biskra Algerie Laboratoire de Couches Minces et Interfaces Faculte des Sciences Universite de Constantine Algeria Laboratory of Semiconductors Nanostructures and Advanced Technology (LSNTA) Research and Technology Centreof Energy BorjCedria Science and Technology Park BP 95 2050 Hammam-Lif Tunisia Department of Physics Faculty of Sciences King Abdulaziz University Djeddah KSA

The aim of this work is to investigate the dependence of Zn S thin films structural and optical properties with the solution flow rate during the deposition using an ultrasonic spray method. The solution flow rate ranged from 10 to 50 m L/h and the substrate temperature was maintained at 450 °C. The effect of the solution flow rate on the properties of Zn S thin films was investigated by X-ray diffraction（XRD）, scanning electron microscopy（SeM）, optical transmittance spectroscopy（UV–V） and the four-point method. The X-ray diffraction analysis showed that the deposited material was pure zinc sulphide, it has a cubic sphalerite structure with preferential orientation along the（111） direction. The grain size values were calculated and found to be between 38 to 82 *** analysis revealed that the deposited thin films have good adherence to the substrate surfaces, are homogeneous and have high density. The average transmission of all films is up more than 65% in the range wavelength from 200 to 1100 nm and their band gap energy values were found between 3.5–3.92 e V. The obtained film thickness varies from 390 to 1040 nm. Moreover, the electric resistivity of the deposited films increases with the increasing of the solution flow rate between 3.51 × 10^5 and 11 × 10^5 Ω·cm.

关键词： zinc sulphide X-ray diffraction ultrasonic spray solution flow rate optical and electrical properties

Schrodinger equation for an Open System

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Chinese Physics Letters 2002年第9期19卷 1238-1243页

作者：毕桥 h.e.Ruda ComplexityScienceCenter YangzhouUniversityYangzhou225002 energeniusCentreforAdvancednanotechnology UniversityofTorontoTorontoM5S3E4Canada

We present a Schr?dinger (Liouville) type of equation for a quantum open system. It has a correlated part, and various master equations may be its special cases. It also has significant applications for constructing decoherence-free subspace for quantum computation. It is related to the original Schrodinger (Liouville) equation for the total system through a non-unitary similarity transformation. It is unnecessary for its correlated part to be self-adjoint, so there is a complex spectrum for the corresponding hamiltonian (Liouvillian), which enables the time evolution of states to be asymmetric. This shows just the correlation to produce evolution of world.

关键词： Liouville equation

First-principles study of the structural,elastic,electronic,optical,and vibrational properties of intermetallic Pd_2Ga

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Chinese Physics B 2012年第3期21卷 341-348页

作者： Yildirim A Koc h Deligoz e Department of Physics Siirt University Department of Physics Aksaray University

The structural, elastic, electronic, optical, and vibrational properties of the orthorhombic Pd2Ga compound are investigated using the norm-conserving pseudopotentials within the local density approximation in the frame of density functional theory. The calculated lattice parameters have been compared with the experimental values and found to be in good agreement with these results. The second-order elastic constants and the other relevant quantities, such as the Young＇s modulus, shear modulus, Poisson＇s ratio, anisotropy factor, sound velocity, and Debye temperature, have been calculated. It is shown that this compound is mechanically stable after analysing the calculated elastic constants. Furthermore, the real and imaginary parts of the dielectric function and the optical constants, such as the optical dielectric constant and the effective number of electrons per unit cell, are calculated and presented. The phonon dispersion curves are derived using the direct method. The present results demonstrate that this compound is dynamically stable.

关键词： Pd2Ga vibrational properties optical properties elastic constants