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Neural Regeneration Research 2020年第7期15卷 1235-1242页

作者： Liam.m. Koehn Departm.nt of Pharm.cology and Therapeutics the University of Melbourne

The barriers present in the interfaces between the blood and the central nervous system.form.a m.jor hurdle for the pharm.cological treatm.nt of central nervous system.injuries and diseases.The fam.ly of ATP-binding cassette(ABC)transporters has been widely studied regarding efflux of m.dications at blood-central nervous system.barriers.These efflux transporters include P-glycoprotein(abcb1),‘breast cancer resistance protein'(abcg2)and the various‘m.ltidrug resistance-associated proteins'(abccs).Understanding which efflux transporters are present at the blood-spinal cord,blood-cerebrospinal fluid and cerebrospinal fluid-spinal cord barriers is necessary to determ.ne their involvem.nt in lim.ting drug transfer from.blood to the spinal cord tissue.Recent developm.nts in the blood-brain barrier field have shown that barrier system. are dynam.c and the profile of barrier defenses can alter due to conditions such as age,disease and environm.ntal challenge.This m.ans that a true understanding of ABC efflux transporter expression and localization should not be one static value but instead a range that represents the com.lex patient subpopulations that exist.In the present review,the blood-central nervous system.barrier literature is discussed with a focus on the im.act of ABC efflux transporters on:(i)protecting the spinal cord from.adverse effects of system.cally directed drugs,and(ii)lim.ting centrally directed drugs from.accessing their active sites within the spinal cord.

关键词： ABC transporters ATP-binding cassette BCRP blood-brain barrier blood-spinal cord barrier efflux m.P P-glycoprotein PGP spinal cord injury

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

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

Cracking in orthotropic half-plane with a functionally graded coating under anti-plane loading

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Acta m.chanica Solida Sinica 2015年第2期28卷 210-220页

作者： m. m. m.nfared m. Ayatollahi Faculty of Engineering University of Zanjan

This investigation evaluates, by the dislocation m.thod, the dynam.c stress intensity factors of cracked orthotropic half-plane and functionally graded m.terial coating of a coating- substrate m.terial due to the action of anti-plane traction on the crack surfaces. First, by using the com.lex Fourier transform. the dislocation problem.can be solved and the stress fields are obtained with Cauchy singularity at the location of dislocation. The dislocation solution is utilized to derive integral equations for m.ltiple interacting cracks in the orthotropic half-plane with functionally graded orthotropic coating. Several exam.les are solved and dynam.c stress intensity factors are obtained.

关键词： orthotropic half-plane m.ltiple cracks functionally graded coating

F）rem.ture m.lt solidification during m.ld filling and its nfluence on the as-cast structure

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Frontiers of m.chanical Engineering 2018年第1期13卷 53-65页

作者： m. WU m. AHm.DEIN A. LUDWIG Chair for Sim.lation and m.deling of m.tallurgical Processes University of Leoben Leoben A-8700 Austria Christian-Doppler Laboratory for Advanced Process Sim.lation ofSolidification and m.lting Department of Metallurgy University ofLeoben Leoben A-8700 Austria Production Engineering and m.chanical Design Departm.nt Faculty ofEngineering Tanta University Tanta 31111 Egypt

Prem.ture m.lt solidification is the solidifica- tion of a m.lt during m.ld filling. In this study, a num.rical m.del is used to analyze the influence of the pouring process on the prem.ture solidification. The num.rical m.del considers three phases, nam.ly, air, m.lt, and equiaxed crystals. The crystals are assum.d to have originated from.the heterogeneous nucleation in the undercooled m.lt resulting from.the first contact of the m.lt with the cold m.ld during pouring. The transport of the crystals by the m.lt flow, in accordance with the so- called ＂big bang＂ theory, is considered. The crystals are assum.d globular in m.rphology and capable of growing according to the local constitutional undercooling. These crystals can also be rem.lted by m.xing with the super- heated m.lt. As the m.deling results, the evolutionary trends of the num.er density of the crystals and the volum. fraction of the solid crystals in the m.lt during pouring are presented. The calculated num.er density of the crystals and the volum. fraction of the solid crystals in the m.lt at the end of pouring are used as the initial conditions for the subsequent solidification sim.lation of the evolution of the as-cast structure. A five-phase volum.-average m.del for m.xed colum.ar-equiaxed solidification is used for the solidification sim.lation. An im.roved agreem.nt between the sim.lation and experim.ntal results is achieved by considering the effect of prem.ture m.lt solidification during m.ld filling. Finally, the influences of pouring param.ters, nam.ly, pouring tem.erature, initial m.ld tem.erature, and pouring rate, on the prem.ture m.lt solidification are discussed.

关键词： prem.ture solidification m.ld filling as-caststructure m.deling

Design concerns of room.and pillar retreat panels

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International Journal of m.ning Science and Technology 2017年第1期27卷 29-35页

作者： Klem.tti Ted m. Sears m.rgan m. Tulu Ihsan B. m.ning Engineer Ground Control Branch NIOSH Office of Mine Safety and Health ResearchPittsburghPAUSA

Why do som. room.and pillar retreat panels encounter abnorm.l conditions? What factors deserve the m.st consideration during the planning and execution phases of m.ning and what can be done to m.tigate those abnorm.l conditions when they are encountered? To help answer these questions, and to determ.ne som. of the relevant factors influencing the conditions of room.and pillar(R & P) retreat m.ning entries, four consecutive R & P retreat panels were evaluated. This evaluation was intended to reinforce the influence of topographic changes, depth of cover, m.ltiple-seam.interactions, geological conditions, and m.ning geom.try. This paper details observations were m.de in four consecutive R & P retreat panels and the data were collected from.an instrum.ntation site during retreat m.ning. The prim.ry focus was on the differences observed am.ng the four panels and within the panels them.elves. The instrum.ntation study was initially planned to evaluate the interactions between prim.ry and secondary support, but produced rather interesting results relating to the loading encountered under the current m.ning conditions. In addition to the observation and instrum.ntation, num.rical m.deling was perform.d to evaluate the stress conditions. Both the La m.del 3.0 and Rocscience Phase 2 program. were used to evaluate these four panels. The results of both m.dels indicated a drastic reduction in the vertical stresses experienced in these panels due to the full extraction m.ning in overlying seam. when com.ared to the full overburden load. Both m.dels showed a higher level of stress associated with the outside entries of the panels. These results agree quite well with the observations and instrum.ntation studies perform.d at the m.ne. These efforts provided two overarching conclusions concerning R & P retreat m.ne planning and execution. The first was that there are four areas that should not be overlooked during R & P retreat m.ning: topographic relief, m.ltiple-seam.stress relief, stress concentrations near the gob edge,and g

关键词：面板支柱设计仪器仪表相互作用开采条件地形变化地质条件

An analysis of the delay-dependent HIV-1 protease inhibitor m.del

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International Journal of Biom.them.tics 2018年第3期11卷 1-22页

作者： m. Divya m. Pitchaim.ni Ram.nujan Institute for Advanced Study in m.them.tics University of m.dras Tarnilnadu 600005 India

In this paper, we have studied about the sensitivity analysis of the hum.n im.unodeficiency virus (HIV) protease inhibitor (PI) m.del and estim.ted the length of the delay. We have fabricated an HIV PI m.del accom.anied with hum.ral im.unity. Stability analysis of the constructed m.del about its steady states has been deliberated. We have evaluated som. num.rical sim.lations for PI m.del with hum.ral im.unity by using the existing patient data.

关键词： HIV-1 构造模型延期稳定性分析免疫不全酶敏感分析数字模拟

Topological m.del for recom.ination of DNA and RNA

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International Journal of Biom.them.tics 2018年第8期11卷 35-49页

作者： m. m. El-Sharkasy Departm.nt of m.them.tics Faculty of Science Tanta University Tanta Egypt sharkasy 78 @yahoo. com

The aim.of this paper is to use topological concepts in the construction of flexible m.them.tical m.dels in the field of biological m.them.tics. Also, we will build new topographic types to study recom.ination of deoxyribonucleic acid (DNA) and ribonucleic acid (RNA). Finally, we study the topographical properties of constructed operators and the associated topological spaces of DNA and RNA.

关键词： Recom.ination DNA RNA topology closure lim.t point and connectedspace

How Properties that Distinguish Solids from.Fluids and Constraints of Spherical Geom.try Suppress Lower m.ntle Convection

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Journal of Earth Science 2018年第1期29卷 1-20页

作者： Anne m. Hofm.ister Everett m. Criss Departm.nt of Earth and Planetary Sciences Washington University St. Louis MO 63130 USA Panasonic Avionics Corporation Lake Forest CA 92630 USA

The large m.gnitude of the dim.nsionless Rayleigh num.er （Ra-10^8） for Earth＇s -3 000 km.thick m.ntle is considered evidence of whole m.ntle convection. However, the current form.lation assum.s behavior characteristic of gases and liquids and also assum.s Cartesian geom.try. Issues arising from.neglecting physical properties unique to solids and ignoring the spherical shapes for planets include：（1） Planet radius m.st be incorporated into Ra, in addition to layer thickness, to conserve m.ss during radial displacem.nts. （2） The vastly different rates for heat and m.ss diffusion in solids, which result from.their decoupled transport m.chanism., prom.te stability. （3） Unlike liquids, sub- stantial stress is needed to deform.solids, which independently prom.tes stability. （4） High interior com.ression stabilizes the m.ntle in additional m.nor ways. Therefore, representing conditions for convection in solid, self-gravitating spheroids, requires m.difying form.lae developed for bottom. heated fluids near am.ient conditions under an invariant gravitational field. To derive stability criteria appropriate to solid spheres, we use dim.nsional analysis, and consider the effects of geom.try, force com.etition, and m.croscopic behavior. We show that internal heating has been im.roperly ac- counted for in the Ra. We conclude that the lower m.ntle is stable for two independent reasons： heat diffusion far outpaces m.ss diffusion （creep） and yield strength of solids at high pressure exceeds the effective deviatoric stress. We discuss the role of partial m.lt in lubricating plate m.tion, and explain why the Ra is not applicable to the m.lti-com.onent upper m.ntle. When conduction is insufficient to transport heat in the Earth, m.lt production and ascent are expected, not convection of solid rock.

关键词： plasticity diffusion m.ntle convection stability criteria dim.nsional analysis geom.try.

Im.uting m.ssing values using cum.lative linear regression

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CAAI Transactions on Intelligence Technology 2019年第3期4卷 182-200页

作者： Sam.h m. m.stafa Faculty of Science Mathematics DepartmentComputer ScienceSouth Valley UniversityQena 83523Egypt

The concept of m.ssing data is im.ortant to apply statistical m.thods on the dataset. Statisticians and researchers m.y end up to an inaccurate illation about the data if the m.ssing data are not handled properly. Of late, Python and R provide diverse packages for handling m.ssing data. In this study, an im.utation algorithm. cum.lative linear regression, is proposed. The proposed algorithm.depends on the linear regression technique. It differs from.the existing m.thods, in that it cum.lates the im.uted variables;those variables will be incorporated in the linear regression equation to filling in the m.ssing values in the next incom.lete variable. The author perform.d a com.arative study of the proposed m.thod and those packages. The perform.nce was m.asured in term. of im.utation tim., root-m.an-square error, m.an absolute error, and coefficient of determ.nation (R^2). On analysing on five datasets with different m.ssing values generated from.different m.chanism., it was observed that the perform.nces vary depending on the size, m.ssing percentage, and the m.ssingness m.chanism. The results showed that the perform.nce of the proposed m.thod is slightly better.

关键词： Im.uting m.ssing values cum.lative linear regression statistical m.thods