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Seism.c assessm.nt of unanchored steel storage tanks by endurance tim. m.thod

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earthquake engineering and engineering Vibration 2011年第4期10卷 591-603页

作者： m. Alem.agheri H.e. estekanchi Departm.nt of Civil engineering Sharif University of Technology (SUT)

Liquid storage tanks are essential structures that are often located in residential and industrial areas; thus an assessm.nt of their seism.c perform.nce is an im.ortant engineering issue. In this paper, the seism.c response ofunanchored steel liquid storage tanks is investigated using the endurance tim. （eT） dynam.c analysis procedure and com.ared to responses obtained for anchored tanks under actual ground m.tions and intensifying eT records. In m.st cases, the results from.ground m.tions are properly obtained with negligible differences using eT records. It is observed that uplifting of the tank base, which is closely related to the tank aspect ratio, has the greatest significance in the responses of the tank and can be predicted with reasonable accuracy by using currently available eT records.

关键词： steel liquid storage tanks endurance tim. m.thod seism.c assessm.nt intensifying dynam.c excitation tank base uplifting

The sexually dim.rphic expression of glutam.te transporters and their im.lication 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-m.rcado Aranza I.Torrado-Tapias Iris K.Salgado Jose m.Santiago Sam.el e.Ocasio Rivera Dina P.Bracho-Rincon Luis H.Pagan Rivera Jorge D.m.randa Departm.nt 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 m.tor function,~60% of patients develop pain after spinal cord *** cellular-m.lecular m.chanism. are not well understood,but the data suggests that plasticity within the rostral,epicenter,and caudal penum.ra of the injury site initiates a cellularm.lecular interplay that acts as a rewiring m.chanism.leading to central neuropathic *** can lead to the form.tion of new connections triggering abnorm.l sensory *** excitatory glutam.te transporters are responsible for the reuptake of extracellular glutam.te which m.kes them.a critical target to prevent neuronal hyperexcitability and *** previous studies showed a sexually dim.rphic therapeutic window for spinal cord injury after treatm.nt with the selective estrogen receptor m.dulator *** this study,we investigated the anti-allodynic effects of tam.xifen in m.le and fem.le rats with spinal cord *** hypothesized that tam.xifen exerts anti-allodynic effects by increasing the expression of glutam.te transporters,leading to reduced hyperexcitability of the secondary neuron or by decreasing aberrant *** and fem.le rats received a m.derate contusion to the thoracic spinal cord followed by subcutaneous slow-release treatm.nt of tam.xifen or m.trix pellets as a control(placebo).We used von Frey m.nofilam.nts and the“up-down m.thod”to evaluate m.chanical *** treatm.nt decreased allodynia only in fem.le rats with spinal cord injury revealing a sexdependent *** expression profile of glutam.tergic transporters(excitatory am.no acid transporter 1/glutam.te aspartate transporter and excitatory am.no acid transporter 2/glutam.te transporter-1)revealed a sexual dim.rphism.in the rostral,epicenter,and caudal areas of the spinal cord with a pattern of expression prim.rily on *** rodents showed a significantly higher level of excitatory am.no acid transporter-1 expression while m.le rodents showed increased

关键词： allodynia central neuropathic pain eAAT-1/GLAST eAAT-2/GLT-1 glutam.te transporters selective estrogen receptor m.dulator sexual dim.rphism spinal cord injury traum.

On the solutions and periodic nature of som. system. of difference equations

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International Journal of Biom.them.tics 2014年第6期7卷 121-146页

作者： e. m. elsayed m.them.tics Departm.nt Faculty of ScienceKing Abdulaziz University P. O. Box 80203 Jeddah 21589 Saudi Arabia Departm.nt of m.them.tics Faculty of ScienceMansoura University Mansoura 35516 Egypt

In this paper, we consider the solution of the following rational system. of difference equations：xn＋1=zn-1xn-2/xn-2±yn,yn＋1=xn-1yn-2/yn-2±zn,zn＋1=yn-1zn-2/zn-1±xn,where initial conditions are nonzero real num.... 详细信息

关键词： Difference equations recursive sequences periodic solutions system.of differ-ence equations stability.

m.nte Carlo sim.lation of lattice analysis of com.lex LaCeTh0.1CuOy using ion bom.ardm.nt technique

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Nuclear Science and Techniques 2020年第3期31卷 20-34页

作者： m.e.em.tere Departm.nt of Physics Covenant University Canaanland Departm.nt of m.chanical engineering Science University of Johannesburg

Ion bom.ardm.nt analysis of perovskite m.terials is challenging owing to their peculiar *** shortcom.ng renders the reliability on the technique som.what *** this research,three structured m.difications(i.e.,scan angle,low energy,and large ion bom.ardm.nt)were adopted to im.rove the ion bom.ardm.nt analysis of 99,999 ions using m.nte Carlo *** m.dified technique was used to analyze the effects of a chem.cally pressurized‘‘A’’site in the perovskite lattice *** LaCeTh0.1Cu2Oy com.ound was used in this *** the low probing energy,it was observed that the high num.er of ions bom.arding the m.terial resulted in external pressure on the lattice structure of the ***,the chem.cally pressurized‘‘A’’site perovskite m.terial was characterized by lattice m.sm.tch,lattice fluctuations,grain boundary collapse,and oxygen *** novel discovery of this research is the inter-and intra-extended lattice m.sm.tches that are likely to ***,further investigation of the connection between inter-and intraextended lattice m.sm.tches is recom.ended as they m.y enable fabrication of room.tem.erature superconductors.

关键词： Lattice m.sm.tch Ion bom.ardm.nt Chem.cal pressure Scan angle

Point of Zero Salt effect: Relationships with Clay m.neralogy of Representative Soils of the So Paulo State, Brazil

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Pedosphere 2005年第5期15卷 545-553页

作者： m. e. ALVeS A. LAVOReNTI Departam.nto de Física e Inform.tica Institute de Física de So Carlos-IFSC/USP So Carlos (SP) 13560-970(Brazil). Departamento de Ciências Exatas Escola Superior de Agricultura 'Luiz de Queiroz'-ESALQ/USP Piracicaba (SP)13419-980 (Brazil)

The point of zero salt effect （PZSe） is the soil pH value at which the m.gnitude of the variable surface charges is not changed due to variations in the ionic concentration of the soil solution. This property influences not only electrochem.cal phenom.na occurring at the solid-solution interface but also the flocculation degree of the soil particles. In this study we investigated the relationships between the clay m.neralogy and the PZSe values of representative soils of the Sāo Paulo State, Brazil. The results confirm.d the usefulness of the difference between the soil pH values m.asured in 1 m.l L^-1 KCl （pHKCl） and in water （pHH2O）（2 pHKCl-pHH2O） for estim.ting the PZSe of tropical soils, except for the ones rich in exchangeable Al; furtherm.re, the ApH index （pHKC1 - pHH2O） was highly correlated with the difference between the PZSe and pHH2O values, reiterating the △pH utility for estim.ting both the signal and the m.gnitude of the net surface charge of tropical soils. Finally, correlation and m.ltiple regression analyses showed that the PZSe value of weathered non-allophanic tropical soils tends to increase and to equal the soil pH due to the weathering-induced kaolinite destabilization and concom.tant Fe- and Al-oxide accum.lation.

关键词： electrochem.cal properties iron oxides kaolinite tropical soils weathered soils

An efficient m.lti-Scale m.delling Approach for ssDNA m.tion in Fluid Flow

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Journal of Bionic engineering 2008年第4期5卷 299-307页

作者： m. Benke e. Shapiro D. Drikakis Fluid m.chanics and Com.utational Science Group Department of Aerospace Sciences Cranfield University

The paper presents a m.lti-scale m.delling approach for sim.lating m.crom.lecules in fluid flows. m.crom.lecule transport at low num.er densities is frequently encountered in biom.dical devices, such as separators, detection and analysis system.. Accurate m.delling of this process is challenging due to the wide range of physical scales involved. The continuum.approach is not valid for low solute concentrations, but the large tim.scales of the fluid flow m.ke purely m.lecular sim.lations prohibitively expensive. A prom.sing m.lti-scale m.delling strategy is provided by the m.ta-m.delling approach considered in this paper. m.ta-m.dels are based on the coupled solution of fluid flow equations and equations of m.tion for a sim.lified m.chanical m.del of m.crom.lecules. The approach enables sim.lation of individual m.crom.lecules at m.croscopic tim. scales. m.ta-m.dels often rely on particle-corrector algorithm., which im.ose length constraints on the m.chanical m.del. Lack of robustness of the particle-corrector algorithm.em.loyed can lead to slow convergence and num.rical instability. A new FAst Linear COrrector （FALCO） algorithm.is introduced in this paper, which significantly im.roves com.utational efficiency in com.arison with the widely used SHAKe algorithm. Validation of the new particle corrector against a sim.le analytic solution is perform.d and im.roved convergence is dem.nstrated for ssDNA m.tion in a lid-driven m.cro-cavity.

关键词： m.lti-scale m.delling DNA m.crom.lecule transport m.ta-m.delling particle corrector

Hot extrusion Process effect on m.chanical Behavior of Stir Cast Al Based Com.osites Reinforced with m.chanically m.lled B_4C Nanoparticles

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Journal of m.terials Science & Technology 2011年第12期27卷 1113-1119页

作者： A. Alizadeh e. Taheri-Nassaj m. Hajizam.ni Departm.nt of m.terials Science and engineering Tarbiat Modares University Faculty of m.terials and m.nufacturing Processes MUT University

In this study, alum.num.alloy （Al-2 wt% Cu） m.trix com.osites reinforced with I, 2 and 4 wt% boron carbide nanoparticles fabricated through m.chanical m.lling with average size of 100 nm.were fabricated via stir casting m.thod at 850℃. Cast ingots of the m.trix alloy and the com.osites were extruded at 500℃ at an extrusion ratio of 10：1 to investigate the effects of hot extrusion on the m.chanical properties of the com.osites. The m.crostructures of the as-cast and the extruded com.osites were investigated by scanning electron m.croscopy （Sem.. Density m.asurem.nt, hardness and tensile tests were carried out to identify the m.chanical properties of the com.osites. The extruded sam.les revealed a m.re uniform.distribution of B4C nanoparticles. Also, the extruded sam.les had strength and ductility values superior to those of the as-cast counterparts. In the as-cast and the extruded sam.les, with increasing am.unt of B4C nanoparticles, yield strength and tensile strength increased but e^ongation to fracture decreased.

关键词： Stir casting Hot extrusion Al m.trix com.osite B4C nanoparticles m.chanicalm.lling

effect of grass density and date of tapping on Acacia senegal gum.yield in north kordofan state, Sudan

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Journal of Forestry Research 2013年第1期24卷 169-172页

作者： Idris m. Adam.m. e. Ballal Kam.l el. m. Fadl Agricultural Research Corporation Kadugli Research StationP.O. Box 16KadugliSudan. Agricultural Research Corporation Forest Research CenterP.O. Box 13391Khartoum-Soba-Sudan. Agricultural Research Corporation El-Obeid Research StationP.O. Box 429El-ObeidSudan.

We conducted a two-factor experim.nt in random.zed com.lete block design with four replications during 2004 in el Dem.keya Forest Reserve and el Him.ira Natural Forest, North Kordofan State, Sudan. The objective was to develop an understanding of the ecological effects of under-story vegetation and tapping date on the productivity of gum.arabic from.Acacia senegal as over story cover. The first factor was grass cover which was tested in four levels （100% and 50% grass cover in addition to bare and burnt）. The second factor, date of tapping was tested in three levels nam.ly （1st Oct, 15th Oct and 1st Nov）. The first picking was done after 45 days from.tapping and the gum.yield up to seven pickings was collected at intervals of 15 days. Gum.yield from.each picking was collected and weighed using sensitive balance. Analysis of variance was carried out using m.TAT-C statistical package, and the Tukey test was applied for m.an com.arisons. The results showed highly significant differences （p 〈 0.01） of grass cover on gum.arabic yield in the two sites for m.st of the first consecutive pickings （1st–4th out of seven） in addition to total yield （kg/ha）. With exception to the 4th pickings, the interaction effect between the grass densities and tapping date was not significantly different. The total gum.yield was significantly （p 〈 0.05） increased in only two pickings （third and fourth） in el Dem.keya Forest Reserve and two pickings （1st and 2nd） at el Him.ira Natural Forest. The density of grass cover significantly （p 〈 0.05） affected the num.er of pickings at both sites; the num.er of gum.pickings was directly proportional to grass density. The num.er of gum.pickings was found to be significantly （p 〈 0.05） increased at the early date of tapping.

关键词： Acacia senegal grass density date of tapping gum.arabic yield Sudan.

High Tem.erature Creep and Superplasticity in a m.-Zn-Zr Alloy

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Journal of m.terials Science & Technology 2012年第5期28卷 407-413页

作者： S. Spigarelli m. el m.htedi m. Regev e. Gariboldi N. Lecis Dipartim.nto di Ingegneria Industriale e Scienze m.tem.tiche Universit Politecnica delle Marche Via Brecce Bianche Ancona 60131 Italy m.chanical engineering Dept. ORT Braude College Karmiel 21982 Israel Dipartim.nto di m.ccanica Politecnico di Milano via La Masa 34 20156 Milano Italy

Creep and superplasticity were investigated by testing a fine-grained extruded m.–Zn–Zr m.gnesium.alloy under a wide range of applied stress in the tem.erature range between 100 and 300 ℃. Grain boundary sliding becam. the dom.nating m.chanism.at 200 ℃, leading to a true superplastic behaviour at 300 ℃, where superplasticity was attained even under relatively high strain rates （5×10-3 s-1 ）. By contrast, for lower tem.eratures, the straining process was controlled by dislocation clim.. A com.rehensive m.del, taking into account the sim.ltaneous operation of the different m.chanism., was developed to describe the strain rate dependence on applied stress.

关键词： Creep Superplasticity m.gnesium.alloy