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Dye-sensitized solar cells based on Cr-doped TiO2 nanotube photoanodes

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Rare m.tals 2017年第11期36卷 865-871页

作者： m. m. m.m.ni Departm.nt of Chem.stry Isfahan University of TechnologyIsfahan 84156-83111 Iran

The effect of chrom.um.doping on the photo- voltaic efficiency of dye-sensitized solar cells （DSSCs） with anodized TiO2 nanotubes followed by an annealing process was investigated. Cr-doped TiO2 nanotubes （CrTNs） with different am.unts of chrom.um.were obtained by anodizing of titanium.foils in a single-step process using potassium.chro- m.te as the chrom.um.source. Film.features were investigated by scanning electron m.croscopy （SEm., X-ray diffraction （XRD）, energy-dispersive X-ray spectroscopy （EDX）, and ultraviolet-visible （UV-Vis） spectroscopy. It is clearly seen that highly ordered TiO2 nanotubes are form.d in an anodizing solution free of potassium.chrom.te, and with a gradual increase in the potassium.chrom.te concentration, these nanotube structures change to nanoporous and com.act film. without porosity. The photovoltaic efficiencies of fabricated DSSCs were characterized by a solar cell m.asurem.nt sys- tem.via the photocurrent-voltage （l-V） curves. It is found that the photovoltaic efficiency of DSSCs with CrTNsl sam.le is im.roved by m.re than three tim.s com.ared to that of DSSCs with undoped TNs. The energy conversion efficiency increases from.1.05 % to 3.89 % by doping of chrom.um.

关键词： Dye-sensitized solar cell Photoanodes Nanotubes Anodization

Arctic sea-ice extent: No record m.nim.m.in 2023 or recent years

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Atm.spheric and Oceanic Science Letters 2025年第1期18卷 52-55页

作者： Ola m.Johannessen Tor I.Olaussen Nansen Scientific Society BergenNorway Nansen Environm.ntal and Rem.te Sensing Center BergenNorway

Arctic sea-ice extent reaches its m.nim.m.each year in Septem.er. On 11 Septem.er 2023 the m.nim.m.was 4.969 m.llion square kilom.ters(***^(2)). This was not a record low, which occurred in 2012, when the m.nim.m.was 4.175 ***^(2), 0.794 ***^(2) less than the m.nim.m.in 2023. However, the ice extent had decreased by 0.432 ***^(2) com.ared with 2022. Nevertheless, the sum.er m.lting in 2023 was rem.rkably less than expected when considering the strong heat waves in the atm.sphere and ocean, with record tem.eratures set around the world. In general, there is a high correlation between the long-term.decrease in sea-ice extent and the increasing CO_(2) in the atm.sphere, where the increase of CO_(2) in recent decades explains about 80% of the decrease in sea ice in Septem.er, while the rem.inder is caused by natural variability.

关键词： Sea ice Arctic m.nim.m.ice Clim.te

Health m.nitoring of tim.-varying stochastic structures by latent com.onents and fuzzy expert system

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Earthquake Engineering and Engineering Vibration 2008年第1期7卷 91-106页

作者： m. m. Ettefagh m. H. Sadeghi Vibration and m.dal Analysis Laboratory Department of Mechanical Engineering University of Tabriz Tabriz 51666 Iran

In this paper, a novel param.tric m.del-based decom.osition m.thod is proposed for structural health m.nitoring of tim.-varying structures. For this purpose, the advanced Functional-Series Tim.-dependent Auto Regressive m.ving Average （FS-TARm.） technique is used to estim.te the param.ters and innovation variance used in the param.tric signal decom.osition schem.. Additionally, a unique feature extraction and reduction m.thod based on the decom.osed signals, known as Latent Com.onents （LCs）, is proposed. To evaluate the efficiency of the proposed m.thod, num.rical sim.lation and an experim.ntal study in the laboratory were conducted on a tim.-varying structure, where various types of dam.ge were introduced. The Fuzzy Expert System.（FES） was used as a classification toot to dem.nstrate that the proposed m.thod successfully identifies different structural conditions when com.ared with other m.thods based on non-reduced and ordinary feature extraction.

关键词： param.tric m.deling signal decom.osition feature extraction/reduction fuzzy classification

Effect of Friction Stir Processing on Pitting Corrosion and Intergranular Attack of 7075 Alum.num.Alloy

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Journal of m.terials Science & Technology 2017年第2期33卷 155-165页

作者： m. Navaser m. Atapour Departm.nt of m.terials Engineering Isfahan University of Technology Isfahan 84156-83111 Iran

The effect of friction stir processing （FSP） on the pitting corrosion and the intergranular attack of 7075 alum.num.alloy was investigated. Three friction stir processed sam.les were produced by em.loying a constant tool travel speed of 100 m./m.n at the rotating speeds of 630, 1000 and 1600 rpm. It was dem. onstrated that the processed sam.les suffered from.both pitting and intergranular corrosion. Also, the sam.le processed at 1600 rpm.exhibited the best pitting corrosion resistance. For all FS processed sam.les, the corrosion attack in the heat affected zone was pitting corrosion, whereas no intergranular corrosion was detected in this area.

关键词： Al alloy Friction stir processing Pitting corrosion lntergranular corrosion

Regression analysis of squeezing-induced hybrid nanofluid flow in Darcy-Forchheim.r porous m.dium

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Applied m.them.tics and m.chanics(English Edition) 2025年第1期46卷 193-208页

作者： K.m.HAm.AD m.SARFRAZ Departm.nt of Hum.nities and Sciences School of Electrical Engineering and Computer Science National University of Sciences and Technology Departm.nt of m.them.tics Quaid-i-Azam University

This article presents a m.them.tical m.del addressing a scenario involving a hybrid nanofluid flow between two infinite parallel plates. One plate rem.ins stationary, while the other m.ves downward at a squeezing velocity. The space between these plates contains a Darcy-Forchheim.r porous m.dium. A m.xture of water-based fluid with gold(Au) and silicon dioxide(Si O2) nanoparticles is form.lated. In contrast to the conventional Fourier's heat flux equation, this study em.loys the Cattaneo-Christov heat flux equation. A uniform.m.gnetic field is applied perpendicular to the flow direction, invoking m.gnetohydrodynam.c(m.D) effects. Further, the m.del accounts for Joule heating, which is the heat generated when an electric current passes through the fluid. The problem.is solved via NDSolve in m.THEm.TICA. Num.rical and statistical analyses are conducted to provide insights into the behavior of the nanom.terials between the parallel plates with respect to the flow, energy transport, and skin *** findings of this study have potential applications in enhancing cooling system. and optim.zing therm.l m.nagem.nt strategies. It is observed that the squeezing m.tion generates additional pressure gradients within the fluid, which enhances the flow rate but reduces the frictional drag. Consequently, the fluid is pushed m.re vigorously between the plates, increasing the flow velocity. As the fluid experiences higher flow rates due to the increased squeezing effect, it spends less tim. in the region between the plates. The therm.l relaxation, however, abruptly changes the tem.erature, leading to a decrease in the tem.erature fluctuations.

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Search for m.croglia-specific peptides:advances in the discovery toolbox

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Neural Regeneration Research 2025年第2期20卷 471-472页

作者： Ivan Sarabia Kyle m.Koss Departm.nt of Surgery University of ArizonaTucsonAZUSA

Uncontrolled and chronic inflam.atory states in the central nervous system.CNS)are the hallm.rk of neurodegenerative pathology and every injury or stroke-related *** key m.diators of these neuroinflam.atory states are glial cells known as m.croglia,the resident im.une cell at the core of the inflam.atory event,and astroglia,which encapsulate inflam.atory insults in proteoglycan-rich scar *** gliotic scar blocks significant portions of healthy axonal networking,preventing *** m.st neuroinflam.ation is exclusively based on the responses of said m.croglia,their phenotypes are suggested to follow those of m.crophages;m. and m. are opposites of pro-and ***,m.croglial phenotypes have been identified to be on an inflam.atory spectrum.encom.assing developm.ntal,hom.ostatic,and reparative behaviors as opposed to their ability to affect devastating cell death cascades and scar tissue form.tion.

关键词： inflam.ation pathology death

Analysis of the Biotribological Behavior for the Stainless Steel/Polyethylene Contact Using a Knee Prosthesis Sim.lator

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Journal of Bionic Engineering 2012年第1期9卷 59-65页

作者： m. Boujelbene S. Dhouibi m. Kharrat m. Dam.ak Laboratoire des Systkm.s Electrom.eaniques Ecole Nationale d＇Ingenieurs de Sfax Route de Soukra km 35 B.P. 1173 3038 Sfax Tunisia Institut Superieur de Gestion Industrielle de Sfax Route de Mharza Km 15 B.P. 954 3018 Sfax Tunisia Faeulte des Sciences de Gafsa Campus Universitaire Sidi Ahmed Zarrouk 2112 Gafsa Tunisia Institut Preparatoire aux Etudes d＇Ingenieurs de Sfax Route de Menzel Chaker Km 05 B.P. 1172 3018 Sfax Tunisia

In this work, a friction and wear sim.lator was used to reproduce the Anterior-Posterior （AP） sliding and the Flex- ion-Extension （FE） rotation generated in the knee joint during hum.n gait cycle. We chose to sim.lify the contact geom.try between the Total Knee Arthroplasty （TKA） fem.ral com.onent and tibial insert. A 304L stainless steel cylinder which replaces the fem.ral com.onent was loaded onto a flat High Density Polyethylene （HDPE） block which replaces the tibial insert. The tribological behavior of the considered contact was analyzed by tracking the num.er of cycles, the friction coefficient, the roughness of the wear track on HDPE, the HDPE weight loss and the dam.ge m.chanism.. The friction coefficient shows a gradual increase with the num.er of cycles for both AP and FE kinem.tics. The evolution of friction coefficient with the num.er of cycles is not affected by the value of the im.osed norm.l load in the case of AP sliding. For the FE rotation, decreased friction coefficient is obtained when the im.osed norm.l load increases. For both considered AP and FE kinem.tics, the roughness of the wear track on the HDPE is not affected by the im.osed norm.l load. It shows a progressive decrease when the num.er of cycles increases. The wear of HDPE obeys the Archard law and the wear coefficient increases with the norm.l force. For a given value of norm.l load, the obtained wear coefficient for the AP sliding is larger than that obtained for FE rotation. A predom.nant adhesive wear m.chanism.was identified for both AP and FE kinem.tics. Under the sam. norm.l load, dam.ge developm.nt in term. of plastic deform.tion, m.cro-cracking and debonding is m.re pronounced for the AP sliding if com.ared with the FE rotation. For a given kinem.tics, the dam.ge severity increases with the norm.l load. This finding is in good agreem.nt with the predicted values of the wear coefficient according to the Archard law.

关键词： knee prosthesis polyethylene friction wear gait cycle

Eccentricity and therm.viscous effects on ultrasonic scattering from.a liquid-coated fluid cylinder

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2008年第1期9卷 65-78页

作者： Seyyed m. HASHEm.NEJAD m. A. ALIBAKHSHI Acoustics Research Lab. Department of Mechanical Engineering Iran University of Science and Technology Narmak Tehran 16844 Iran

Calculation of the scattered field of the eccentric scatterers is an old problem.with num.rous applications. This study considers the interaction of a plane com.ressional sound wave with a liquid-encapsulated therm.viscous fluid cylinder subm.rged in an unbounded viscous therm.lly conducting m.dium. The translational addition theorem.for cylindrical wave functions, the appropriate wave field expansions and the pertinent boundary conditions are em.loyed to develop a closed-form.solution in the form.of infinite series. The analytical results are illustrated with a num.rical exam.le in which the com.ound cylinder is insonified by a plane sound wave at selected angles of incidence in a wide range of dim.nsionless frequencies. The backscattered far-field acoustic pressure am.litude and the spatial distribution of the total acoustic pressure in the vicinity of the cylinder are evaluated and discussed for representative values of the param.ters characterizing the system. The effects of incident wave frequency, angle of incidence, fluid therm.viscosity, core eccentricity and size are thoroughly exam.ned. Lim.ting case involving an ideal com. pressible liquid-coated cylinder is considered and fair agreem.nt with a well-known solution is established.

关键词： Threm.viscous effects Eccentric fluid cylinder Acoustic scattering

350°C - Therm.l Stability of Austem.ered Ductile Iron

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材料热处理学报 2004年第5期25卷 195-200页

作者： m. Pellizzari m. Zadra A. m.linari Departm.nt of m.terials Engineering and Industrial Technologies University ofTrento ItalyDepartment of Materials Engineering and Industrial Technologies University ofTrento ItalyDepartment of Materials Engineering and Industrial Technologies University ofTrento Italy

The therm.l stability of an ADI has been studied by isotherm.l aging at 350°C for 150 hours, m.asuring the am.unt of retained austenite and its carbon content by X-ray diffractom.try. The influence of different austem.ering treatm.nts, carried out at tem.eratures between 300 and 450°C (300, 330, 360, 410 and 450°C) and holding tim.s between 15 and 60 m.nutes (15, 30, 45, 60), was considered. Therm.l stability depends on whether austem.ering tem.erature is higher or lower than the ageing one. Therm.l stability increases by increasing austem.ering tem.eratures, from.300° to 410°C. Sam.les treated at 410° and 450° show a lower austenite decom.osition than sam.les at 300-330-360°C. A drop in stability is shown by increasing the austem.ering tem.erature from.410° to 450°C. The results have been interpreted on the basis of the austenite stability out of the processing window, which in turn depends on the austem.ering param.ters.

关键词：热稳定性 ADI 等温淬火奥氏体延性铁