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Die in pieces:how Drosophila sheds light on neurite degeneration and clearance

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Journal of Genetics and Genomics 2019年第4期46卷 187-199页

作者： Maria l.Sapar Chun han Weill Institute for Cell and Molecular Biology Department of Molecular Biology and GeneticsCornell University

Dendrites and axons are delicate neuronal membrane extensions that undergo degeneration after physical injuries. In neurodegenerative diseases, they often degenerate prior to neuronal death. Understanding the mechanisms of neurite degeneration has been an intense focus of neurobiology research in the last two decades. As a result, many discoveries have been made in the molecular pathways that lead to neurite degeneration and the cell-cell interactions responsible for the subsequent clearance of neuronal debris. Drosophila melanogaster has served as a prime in vivo model system for identifying and characterizing the key molecular players in neurite degeneration, thanks to its genetic tractability and easy access to its nervous system. The knowledge learned in the fly provided targets and fuel for studies in other model systems that have further enhanced our understanding of neurodegeneration. In this review, we will introduce the experimental systems developed in Drosophila to investigate injuryinduced neurite degeneration, and then discuss the biological pathways that drive degeneration. We will also cover what is known about the mechanisms of how phagocytes recognize and clear degenerating neurites, and how recent findings in this area enhance our understanding of neurodegenerative disease pathology.

关键词： Drosophila Neurite degeneration Axon Dendrite Wallerian degeneration Phagocyte Phagocytosis PS exposure Injury assay

STUDy oN SEVERAl INFlUENCE FACToRS oF WElDED STRUCTURES IN FATIGUE TEST

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STUDY ON SEVERAL INFLUENCE FACTORS OF WELDED STRUCTURES IN F...

Effect of high Density Pulsing Current on Mechanical Properties of Fe-6.5wt.%Si Alloy Sheet

第一届国际机械工程学术会议

作者： liu G N Zhang X h Zhao M h liu y J (NAMT Center Zhengzhou Research Institute of Mechanical Engineering)Zhang J S liu T Tao y liu y (CAD Center Zhengzhou Research Institute of Mechanical Engineering)

＜正＞ Three steel materials used widely in Chinese industry[l] have been chosen to study the fatigue characters of welded structures under various *** on the fatigue testing results that correspond to different stress ratios,loading methods,and dimensions of the welded joints,the relations among these influential factors are obtained mat may help predict the fatigue lives under an actual *** addition,the stress analyses are also made to find out the influence of the shape of a welding line on the fatigue life of a welded joint

关键词： Welded structures Fatigue Influence factors SCF S-N curves

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Effect of High Density Pulsing Current on Mechanical Propert...

ElECTRoRhEoloGy AND CREEP-RECoVERy BEhAVIoR oF CoNDUCTING PolyThIoPhENE/Poly(oXyMEThylENE)-BlEND SUSPENSIoNS

中国材料大会2012

作者： h.C.Zhou y.F.liang F.ye G.y.Tang J.P.lin State Key laboratory for Advanced Metals and Materials University of Science and Technology Beijing Advanced Materials Institute Graduate School at ShenzhenTsinghua University

ISBN: (纸本)9783037856093

It is well known that excellent soft magnetic properties are obtained in electrical steel with Si content of 6.5wt.%,such as high permeability,low coercive force,near zero magnetostriction,*** due to its poor ambient temperature ductility it is very hard to fabricate this material by conventional hot-cold rolling ***,high-density electropulsing treatment（EPT） attracts widespread applications as a new heat treatment *** this paper,heat treatment effect of high-density pulsing current on microstructure,micro-hardness and mechanical properties of as rolled Fe-6.5wt.%Si alloy sheet were *** results showed that the microstructure and mechanical properties were closely related to the parameters of the *** and uniform recrystallized grains were obtained by optimizing parameters of the high density *** with the conventional heat treatment method,the time and temperature for heat treatment can be reduced ***,it is considered that EPT is an efficient heat treatment approach for this rolled *** of the effect of high-density pulsing current has been discussed also in this investigation.

关键词： high-density pulsing current Fe-6.5wt.%Si alloy Recrystallization Mechanical properties

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Chinese Journal of Polymer Science 2012年第1期30卷 16-25页

作者： ozlem Erol h.Ibrahim Unal Bekir Sari Smart Materials Research lab Chemistry Department Gazi UniversityAnkaraTurkey

Electrorheological properties and creep-recovery behavior of polythiophene/polyoxymethylene-blend having PT（50%）/PoM（50%） composition were *** size,conductivity and dielectric values were measured to be 24.77μm,3.85×10^（-5） S·m^（-1） and 26.75,*** ratio was measured to be 64%at the end of 16 *** effects of dispersed particle volume fraction,external electric field strength,shear rate,frequency and temperature on ER properties and storage modulus of PT/PoM-blend/silicone oil（So） suspensions were *** were observed in the electric field viscosities of the suspensions and thus they were classified as a smart *** thinning non-Newtonian viscoelastic behavior was determined for PT/PoM-blend/So ***,time-dependent deformation was examined by creep-recovery tests and recoverable viscoelastic deformation established.

关键词： Conducting polythiophene/poly(oxymethylene) Blends Electrorheogical fluids Creep-recovery behavior

Effect of Welding Parameters on GTA Weld Shape for Pure Iron Plate under Ar-o_2 Mixed Shielding

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Journal of Materials Science & Technology 2006年第3期22卷 359-366页

作者： ShanDing lU h.Fujii K.Nogi Institute of Metal Research Chinese Academy of Sciences Shenyang 110016 China Joining and Welding Research Institute Osaka University 11-1 Mihogaoka ibaraki Osaka 567-0047 Japan

Weld shape variation for different welding parameters is investigated on pure iron plate under gas tungsten arc （GTA） welding with argon-oxygen mixed shielding. Results showed that small addition of oxygen to the argon base shielding gas can effectively adjust the oxygen adsorption to the molten pool. An inward Marangoni convection occurs on the pool surface when the oxygen content in the weld pool is over the critical value, 80×10^-6, for pure iron plate under Ar-0.3%o2 mixed shielding. low oxygen content in the weld pool changes the inward Marangoni to an outward direction under the Ar-0.1%o2 shielding. The GTA weld shape depends to a large extent on the pattern and strength of the Marangoni convection on the pool surface, which is determined by the content of surface active element, oxygen, in the weld pool and the welding parameters. The strength of the Marangoni convection on the liquid pool is a product of the temperature coefficient of the surface tension （dσ/dT） and the temperature gradient （dT/dr） on the pool surface. Different welding parameters will change the temperature distribution and gradient on the pool surface, and therefore, affect the strength of Marangoni convection and the weld shape.

关键词： Weld shape oxygen Marangoni convection Mixed shielding gas

Simultaneous observations of large-scale traveling ionospheric disturbances on the nightside and dayside middle latitude

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Simultaneous observations of large-scale traveling ionospher...

Multi-material additive manufacturing-functionally graded materials by means of laser remelting during laser powder bed fusion

中国空间科学学会空间物理学专业委员会第十五届全国日地空间物理学研讨会

作者： h.T.Cai F.yin S.y.Ma J.S.Xu y.W.liu Department of Space Physics School of Electronic InformationWuhan University Key laboratory of Geospace Environment and Geodesy Ministry of Education of PRC

In this paper,we present further observational evidences for the trans-polar propagation of large-Scale Traveling Ionospheric Disturbances(lSTIDs)from their nightside source region to the dayside reported by Cai et al.(2011).Slant Total Electron Content(STEC)observed by longitudinally-aligned GPS receiver chains in North American and European sectors were analyzed to demonstrate presences of lSTIDs at both nightside and dayside *** of TID were inferred from phase difference in time series of STEC perturbations(TECP)derived from measurements of ground-based GPS receivers,which are separated by hundreds kilometer *** of the day-time and night-time ionospheric disturbances were estimated to be around 128 minutes,being in good agreement with that of the trans-polar AGW recorded by EISCAT/ESR *** the dayside,the lSTID moved equatorward with an average phase speed of40 m/*** North American sector,however,southward speed of the night-time lSTID was much slower,being around 160 m/*** suggest that the observed day-time and night-time mid-latitude lSTIDs are likely to have the same source region,being located somewhere at night-time auroral *** been launched on the nightside,the waves propagate simultaneously equatorward and *** equatorward moving waves are recorded by GPS receiver chain in North American *** poleward-moving waves,however,cross the polar cap from nightside to dayside and then are detected consecutively at high-and mid-latitudes by EISCAT/ESR radars and GPS receiver chains,respectively.

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Frontiers of Mechanical Engineering 2023年第4期18卷 183-193页

作者： Alexander SChMIDT Felix JENSCh Sebastian hÄRTEl Chair of hybrid Manufacturing Brandenburg University of TechnologyCottbus 03046Germany

Many processes may be used for manufacturing functionally graded *** them,additive manufacturing seems to be predestined due to near-net shape manufacturing of complex geometries combined with the possibility of applying different materials in one *** adjusting the powder composition of the starting material layer by layer,a macroscopic and step-like gradient can be *** further improve the step-like gradient,an enhancement of the in-situ mixing degree,which is limited according to the state of the art,is *** this paper,a novel technique for an enhancement of the in-situ material mixing degree in the melt pool by applying laser remelting(lR)is *** effect of layer-wise lR on the formation of the interface was investigated using pure copper and low-alloy steel in a laser powder bed fusion *** cross-sectional selective electron microscopic analyses were carried *** applying lR,the mixing degree was enhanced,and the reaction zone thickness between the materials was ***,an additional copper and iron-based phase was formed in the interface,resulting in a smoother gradient of the chemical composition than the case without *** Marangoni convection flow and thermal diffusion are the driving forces for the observed effect.

关键词： multi-material additive manufacturing(MMAM) functionally graded materials(FGMs) laser powder bed fusion(l-PBF) laser remelting(lR) pure copper

Influence of porosity distribution on nonlinear free vibration and transient responses of porous functionally graded skew plates

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Defence Technology（防务技术） 2021年第6期17卷 1918-1935页

作者： Naveen Kumar h S Subhaschandra Kattimani TNguyen-Thoi Department of Mechanical Engineering National Institute of Technology KarnatakaSurathkal575025India Division of Computational Mathematics and Engineering Institute for Computational ScienceTon Duc Thang UniversityHo Chi Minh CityViet Nam Faculty of Civil Engineering Ton Duc Thang University Ho Chi Minh CityViet Nam

This article deals with the investigation of the effects of porosity distributions on nonlinear free vibration and transient analysis of porous functionally graded skew(PFGS)*** effective material properties of the PFGS plates are obtained from the modified power-law equations in which gradation varies through the thickness of the PFGS plate.A nonlinear finite element(FE)formulation for the overall PFGS plate is derived by adopting first-order shear deformation theory(FSDT)in conjunction with von Karman’s nonlinear strain displacement *** governing equations of the PFGS plate are derived using the principle of virtual *** direct iterative method and Newmark’s integration technique are espoused to solve nonlinear mathematical *** influences of the porosity distributions and porosity parameter indices on the nonlinear frequency responses of the PFGS plate for different skew angles are studied in various *** effects of volume fraction grading index and skew angle on the plate’s nonlinear dynamic responses for various porosity distributions are illustrated in detail.

关键词： Porous functionally graded skew plates Porosity distributions Nonlinear transient response Nonlinear frequency ratio Nonlinear frequency parameter

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自然降水变异对人工增雨效果评估的影响

中国科学：地球科学 2015年第6期45卷 1011-1019页

作者：吴香华牛生杰金德镇孙海燕南京信息工程大学数学与统计学院南京210044 南京信息工程大学大气物理学院南京210044 南京信息工程大学大气物理与大气环境重点实验室南京210044 吉林省人工影响天气办公室长春130062

效果评估是人工增雨试验中的关键问题之一。降水在时空分布上往往存在自然变异，使得精确估算自然降水量、评估人工增雨的效果变得比较困难．基于吉林省1997-2007年4～7月飞机人工增雨作业的宏观记录资料和降水量日值数据，运用现代统... 详细信息

效果评估是人工增雨试验中的关键问题之一。降水在时空分布上往往存在自然变异，使得精确估算自然降水量、评估人工增雨的效果变得比较困难．基于吉林省1997-2007年4～7月飞机人工增雨作业的宏观记录资料和降水量日值数据，运用现代统计模拟方法“bootstrap”分析自然降水变异，并设法控制其对人工增雨效果评估的影响．研究表明，自然降水变异的影响有三种控制方法：增加催化样本量、删除异常点和选取降水结构相似的对比单元．催化样本量越大，自然降水变异的影响和催化效果的检出下限越小．催化样本量为470时，若要检出20％～30％的增雨效果，置信度可达90％．在单次作业的效果检验中，删除强异常点和选取降水结构相似的对比单元，建立数据删失模型，能够有效地控制自然降水变异的影响，提高人工增雨效果评估的效率．结果显示，吉林省人工增雨相对效果的分布主要集中在0～30％，平均11．95％．人工增雨作业的效果，和降水量大小没有直接联系，而其波动幅度随着降水量增加而逐渐越小．

关键词：人工增雨效果自然降水变异 bootstrap 数据删失模型检出下限