检索结果-南通市图书馆

Negative refractions by triangular lattice sonic crystals in partial band gaps

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2015年第4期24卷 310-321页

作者： s.alagoz B.B.alagoz A.sahin s.Nur Department of Physics Inonu University Department of Electrical and Electronics Engineering Inonu University Vocational school of Health services Medical Imaging Techniques Inonu University

This study numerically demonstrates the effects of partial band gaps on the negative refraction properties of sonic crystal. The partial band gap appearing at the second band edge leads to the efficient transmissions of scattered wave envelopes in the transverse directions inside triangular lattice sonic crystal, and therefore enhances the refraction property of sonic crystal. Numerical simulation results indicate a diagonal guidance of coupled scattered wave envelopes inside crystal structure at the partial band gap frequencies and then output waves are restored in the vicinity of the output interface of sonic crystal by combining phase coherent scattered waves according to Huygens＇ principles. This mechanism leads to two operations for wavefront engineering： one is spatial wavefront shifting operation and the other is convex-concave wavefront inversion operation. The effects of this mechanism on the negative refraction and wave focalization are investigated by using the finite difference time domain （FDTD） simulations. This study contributes to a better understanding of negative refraction and wave focusing mechanisms at the band edge frequencies, and shows the applications of the slab comer beam splitting and sC-air multilayer acoustic system.

关键词： sonic crystal negative refraction wave focusing partial band gap

An Investigation of Ionic Flows in a sphere-Plate Electrode Gap

在线全文

学校读者我要写书评

暂无评论

Plasma science and Technology 2013年第10期15卷 1012-1019页

作者： H.Z.ALIsOY s.alagoz G.T.ALIsOY B.B.alagoz Department of Electrical-Electronics Inonu University Department of Physics Inonu University Department of Mathematics Inonu University

This paper presents analyses of ion flow characteristics and ion discharge pulses in a sphere-ground plate electrode system. As a result of variation in electric field intensity in the electrode gap, the ion flows towards electrodes generate non-uniform discharging pulses. Inspection of these pulses provides useful information on ionic stream kinetics, the effective thickness of ion cover around electrodes, and the timing of ion clouds discharge pulse sequences. A finite difference time domain （FDTD） based space-charge motion simulation is used for the numerical analysis of the spatio-temporal development of ionic flows following the first Townsend avalanche, and the simulation results demonstrate expansion of the positive ion flow and compression of the negative ion flow, which results in non-uniform discharge pulse characteristics.

关键词： ion flow FDTD simulation space charge motion

Modeling and analysis of dielectric materials by using gradient-descent optimization method

在线全文

学校读者我要写书评

暂无评论

International Journal of Modeling, simulation, and scientific Computing 2017年第1期8卷 213-230页

作者： B.B.alagoz H.Z.Alisoy M.Koseoglu s.alagoz Electrical-Electronics Engineering Inonu University Turkey Electronics and Communication Engineering Namik Kemal University Turkey Department of Physics Inonu University Turkey

This study presents a numerical method based on parallel RC equivalent circuit model fitting methodology for analysis and modeling of dielectric *** proposed method employs gradient-descent optimization method(GDOM)to estimate parallel RC equivalent circuit model from current waveforms by minimizing sum of squared difference(ssD)*** of parallel RC equivalent circuit parameters from measured current waveforms provides a useful tool for identification,simulation and analysis of dielectric ***,applications of the proposed method for time and frequency analyses of dielectric materials are demonstrated *** simulations were presented to discuss efficiency of the proposed method for modeling,analysis and monitoring of insulator materials.

关键词： Dielectric materials insulators numerical analysis modeling

Theoretical demonstration of the hybrid focusing points of sonic crystal flat lenses and possible applications

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Physics B 2013年第7期22卷 393-399页

作者： serkan alagoz Baris Baykant alagoz Department of Physics Inonu University Department of Electric-Electronics Inonu University

We demonstrate the hybrid focusing points of sonic crystals for a multi-source array applied to flat sonic crystal lenses. The contributions of different point source couples form hybrid focusing points. Ray-trace analyses are conducted for acoustic flat lenses with multi-source configurations. The finite-difference time-domain （FDTD） simulation of flat lenses with multi-source configurations demonstrates the establishment of pure and hybrid focusing points in a pyramidal constellation. The number of focusing points in the pyramidal constellation depends on the number of point sources. We propose an acoustic device for fine-tuning the location of a far-field hybrid focusing point and discuss its benefits for acoustic energy focusing application.

关键词： negative refraction sonic crystal metamaterials wave focusing acoustic flat lens

A Note on Robust stability Analysis of Fractional Order Interval systems by Minimum Argument Vertex and Edge Polynomials

在线全文

学校读者我要写书评

暂无评论

IEEE/CAA Journal of Automatica sinica 2016年第4期3卷 411-421页

作者： Baris Baykant alagoz Department of Computer Engineering Inonu University

By using power mapping(s =v^m),stability analysis of fractional order polynomials was simplified to the stability analysis of expanded degree integer order polynomials in the first Riemann ***,more investigation is needed for revealing properties of power mapping and demonstration of conformity of Hurwitz stability under power mapping of fractional order characteristic *** of this study have two folds: Firstly,this paper demonstrates conservation of root argument and magnitude relations under power mapping of characteristic polynomials and thus substantiates validity of Hurwitz stability under power mapping of fractional order characteristic *** also ensures implications of edge theorem for fractional order interval ***,in control engineering point of view,numerical robust stability analysis approaches based on the consideration of minimum argument roots of edge and vertex polynomials are *** the computer-aided design of fractional order interval control systems,the minimum argument root principle is applied for a finite set of edge and vertex polynomials,which are sampled from parametric uncertainty *** illustrative examples are presented to discuss effectiveness of these approaches.

关键词： Fractional order systems robust stability edge theorem interval uncertainty

Revisiting cerebral endothelial cells in Alzheimer’s disease

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2025年第10期20卷 2911-2912页

作者： Amira s.Hanafy Department of Neurosurgery University Hospital BonnBonnGermany

Alzheimer’s disease(AD)is the most common neurodegenerative disorder characterized by slow and progressive decline of cognitive and memory *** only approximately 5%of the cases,AD is familial,as often predisposed by genetic mutations(Hoogmartens et al.,2021),while sporadic AD accounts for approximately 95%of the *** amyloid cascade hypothesis is one of the fundamental hypotheses put out to explain AD pathogenesis as dysregulated homeostasis of amyloid-β(Aβ)peptides that leads to the accumulation of Aβplaques in the parenchyma,an anatomical hallmark of AD.

关键词： Alzheimer Aβ cerebral

A systematic review of progenitor survival and maturation in Parkinsonian models

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2025年第11期20卷 3172-3178页

作者： Giulia Comini Eilís Dowd Pharmacology&Therapeutics and Galway Neuroscience Center University of GalwayGalwayIreland

stem cell-based brain repair is a promising emergent therapy for Parkinson's disease based on years of foundational research using human fetal donors as a cell *** current therapeutic options for patients,this approach has the potential to provide longterm stem cell–derived reconstruction and restoration of the dopaminergic input to denervated regions of the brain allowing for restoration of certain functions to *** ultimate clinical success of stem cell–derived brain repair will depend on both the safety and efficacy of the approach and the latter is dependent on the ability of the transplanted cells to survive and differentiate into functional dopaminergic neurons in the Parkinsonian *** the pre-clinical literature suggests that there is considerable variability in survival and differentiation between studies,the aim of this systematic review was to assess these parameters in human stem cell-derived dopaminergic progenitor transplant studies in animal models of Parkinson's disease.A defined systematic search of the PubMed database was completed to identify relevant studies published up to March *** screening,76 articles were included in the analysis from which 178 separate transplant studies were *** these,graft survival could be assessed in 52 studies and differentiation in 129 ***,we found that graft survival ranged froms transplanted,with a median of 51%of transplanted cells surviving in the brain;while dopaminergic differentiation of the cells ranged from 0% to 46% of cells transplanted with a median of 3%.This systematic review suggests that there is considerable scope for improvement in the differentiation of stem cell-derived dopaminergic progenitors to maximize the therapeutic potential of this approach for patients.

关键词： cell replacement therapy differentiation embryonic stem cells graft induced pluripotent stem cells Parkinson's disease survival transplant

Deciphering the mechanobiology of microglia in traumatic brain injury with advanced microsystems

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2025年第8期20卷 2304-2306页

作者： Anthony Procès sylvain Gabriele Univ.Grenoble Alpes InsermU1216Grenoble Institut des NeurosciencesGrenobleFrance Mechanobiology&Biomaterials Group CIRMAPResearch Institute for BiosciencesUniversity of MonsMonsBelgium

Advanced microsystems in traumatic brain injury research:Traumatic brain injury(TBI)results from a mechanical insult to the brain,leading to neuronal and axonal damage and subsequently causing a secondary *** minutes ... 详细信息

关键词： traumatic injury damage

Emerging structures and dynamic mechanisms ofγ-secretase for Alzheimer’s disease

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2025年第1期20卷 174-180页

作者： Yinglong Miao Michael s.Wolfe Computational Medicine Program and Department of Pharmacology University of North Carolina–Chapel HillChapel HillNCUSA Department of Medicinal Chemistry University of KansasLawrenceKSUSA

γ-secretase,called“the proteasome of the membrane,”is a membrane-embedded protease complex that cleaves 150+peptide substrates with central roles in biology and medicine,including amyloid precursor protein and the Notch family of cell-surface *** inγ-secretase and amyloid precursor protein lead to early-onset familial Alzheimer’s disease.γ-secretase has thus served as a critical drug target for treating familial Alzheimer’s disease and the more common late-onset Alzheimer’s disease as ***,critical gaps remain in understanding the mechanisms of processive proteolysis of substrates,the effects of familial Alzheimer’s disease mutations,and allosteric modulation of substrate cleavage byγ-*** this review,we focus on recent studies of structural dynamic mechanisms ofγ-*** mechanisms,including the“Fit-stay-Trim,”“sliding-Unwinding,”and“Tilting-Unwinding,”have been proposed for substrate proteolysis of amyloid precursor protein byγ-secretase based on all-atom molecular dynamics *** an incorrect registry of the Notch1 substrate was identified in the cryo-electron microscopy structure of Notch1-boundγ-secretase,molecular dynamics simulations on a resolved model of Notch1-boundγ-secretase that was reconstructed using the amyloid precursor protein-boundγ-secretase as a template successfully capturedγ-secretase activation for proper cleavages of both wildtype and mutant Notch,being consistent with biochemical experimental *** approach could be potentially applied to decipher the processing mechanisms of various substrates byγ-*** addition,controversy over the effects of familial Alzheimer’s disease mutations,particularly the issue of whether they stabilize or destabilizeγ-secretase-substrate complexes,is ***,an outlook is provided for future studies ofγ-secretase,including pathways of substrate binding and product release,effects of modulators on familial Alzheimer’s disease mutations

关键词： Alzheimer’s disease amyloid precursor protein cryo-EM structures drug design intramembrane proteolysis molecular dynamics Notch