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A perspective on age-related changes in cell environment and risk of neurodegenerative diseases

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Neural Regeneration Research 2024年第4期19卷 719-720页

作者： Alice y.liu Department of Cell Biology.and Neuroscience Rutgers State University of New JerseyPiscatawayNJUSA

“Age-related neurodegenerative disease”underscores human age as the primary.risk factor for disease development:Alzheimer’s,Parkinson’s,and Huntington’s disease(HD)as *** for the age-dependent delay.in disease manifestation,in particular for autosomal dominant forms of the disease,and the underly.ng cause(s)of specific neuron dy.function and death to manifest as memory.loss,anxiety.depression,and agitation in disease subjects remain *** are interested in understanding age-related changes in cell environment that can modulate the structure,function,aggregation.

关键词： Huntington Alzheimer death

Microstructure evolution and shape memory.behaviors of Ni_(47)Ti_(44)Nb_(9)alloy.subjected to multistep thermomechanical loading with different prestrain levels

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Journal of Materials Science & Technology 2024年第4期171卷 80-93页

作者： y.H.Zhang H.Li Z.W.y.ng x.liu Q.F.Gu State Key.Laboratory.of Solidification Processing School of Materials Science and EngineeringNorthwestern Polytechnical UniversityXi’an 710072China Shaanxi Key.Laboratory.of High-Performance Precision Forming Technology.and Equipment Northwestern Polytechnical UniversityXi’an 710072China

Ni_(47)Ti_(44)Nb_(9)shape memory.alloy.SMA)is a promising material in the aerospace field due to its wide transformation *** application of shape memory.effect depends on multistep thermomechan-ical loading,viz.,low-temperature deformation and subsequent heating to ***-temperature deformation prestrain play. a pivotal role in shape memory.properties tailoring of SMA ***,microstructure evolution and deformation mechanisms of Ni_(47)Ti_(44)Nb_(9)SMA subjected to vari-ous prestrain levels are still *** this end,microstructure evolution and shape memory.behaviors of Ni_(47)Ti_(44)Nb_(9)alloy.subjected to multistep thermomechanical loading with prestrain levels of 8%-16%at-28℃(M_(s)+30℃)were *** results demonstrate that the stress-strain curve of the specimen exhibits four distinct stages at a maximal prestrain of 16%.Whereas stageⅡand stageⅢend at prestrains of∼8%and∼12%,*** stageⅡ,the stress-induced martensitic transformation is accompanied by.the dislocation slip of the NiTi matrix andβ-Nb *** stageⅢ,in addition to the higher density.of dislocations and further growth of stress-induced martensite variants(SIMVs),(001)compound twins are introduced as a result of the(001)deformation twinning in stress-induced ***{20-1}martensite twins are gradually.introduced in stageⅣ.Correspondingly.after subsequent unloading and heating,a higher density.of{114}austenite twins form in the specimen with a larger prestrain of 16%.With increasing prestrain from 8%to 16%,the recoverable strainε_(re)^(T)upon heating increases first and then ***ε_(re)^(T)obtains a maximum of 7.03%at 10%prestrain and de-creases to 6.17%at 16%*** increase ofε_(re)^(T)can be attributed to the formation of new SIMVs,the further growth of existing SIMVs,and the recoverable(001)compound *** the decrease ofε_(re)^(T)is mainly.associated with the irrecoverable strain by.20−1}martensite *** effe

关键词： Ni_(47)Ti_(44)Nb_(9)shape memory.alloy Wide transformation hy.teresis Thermomechanical loading Microstructure evolution Shape memory.behaviors Stress-induced martensitic transformation Deformation twinning

Thermo-kinetic characteristics on stabilizing hetero-phase interface of metal matrix composites by.cry.tal plasticity.finite element method

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Journal of Materials Science & Technology 2024年第2期169卷 53-67页

作者： y.B.Zhang S.J.Song F.liu State Key.Laboratory.of Solidification Processing Northwestern Polytechnical UniversityXi’an 710072China Analy.ical&Testing Center Northwestern Polytechnical UniversityXi’an 710072China

Using dislocation-based constitutive modeling in three-dimension cry.tal plasticity.finite element(3D CPFE)simulations,co-deformation and instability.of hetero-phase interface in different material sy.tems were herein studied for poly.ry.talline metal matrix composites(MMCs).Local stress and strain fields in two ty.es of 3lay.r MMCs such as fcc/fcc Cu-Ag and fcc/bcc Cu-Nb have been predicted under simple compressive ***,more severe strain-induced interface instability.can be observed in the fcc/bcc sy.tems than in the fcc/fcc sy.tems upon refining to metallic nanolay.red composites(MNCs).By.detailed analy.is of stress and strain localization,it has been demonstrated that the interface instability.is alway. accompanied by.high-stress concentration,i.e.,thermody.amic characteristics,or high strain prevention i.e.,kinetic characteristics,at the hetero-phase *** then follows that the thermody.amic driving forceG and the kinetic energy.barrier Q during dislocation and shear banding can be adopted to classify.the deformation modes,following the so-called thermo-kinetic *** by.inserting a high density.of high-energy.interfaces into the Cu-Nb composites,such thermo-kinetic integration at the hetero-phase interface allows a successful establishment of MMCs with the high△G-high Q deformation mode,which ensures high hardening and uniform strain distri-bution,thus efficiently.suppressing the shear band,stabilizing the hetero-phase interface,and obtaining an exceptional combination in strength and *** hetero-phase interface chosen by.a couple of thermody.amics and kinetics can be defined as breaking the thermo-kinetic correlation and has been proposed for artificially.designing MNCs.

关键词： Thermody.amics and kinetics Phy.ics-based constitutive modeling Hetero-phase interface Cry.tal plasticity.finite element

Multi-population particle swarm optimization algorithm for automatic design of steel frames

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Frontiers of Structural and Civil Engineering 2024年第1期18卷 89-103页

作者： Wenchen SHAN Jiepeng liu y.o DING y.Frank CHEN Junwen ZHOU Institute of Smart City.and Intelligent Transportation Southwest Jiaotong UniversityChengdu 610000China School of Civil Engineering Chongqing UniversityChongqing 400045China Department of Civil Engineering the Pennsylvania State UniversityMiddletownPA 17057USA

Steel structures are widely.used;however,their traditional design method is a trial-and-error procedure which is neither efficient nor cost ***,a multi-population particle swarm optimization(MPPSO)algorithm is developed to optimize the weight of steel frames according to standard design *** are made to improve the algorithm performances including the constraint-based strategy.piecewise mean learning strategy.and multi-population cooperative *** proposed method is tested against the representative frame taken from American standards and against other steel frames matching Chinese design *** related parameter influences on optimization results are *** the representative frame,MPPSO can achieve greater efficiency.through reduction of the number of analy.es by.more than 65% and can obtain frame with the weight for at least 2.4%lighter.A similar trend can also be observed in cases subjected to Chinese design *** addition,a migration interval of 1 and the number of populations as 5 are recommended to obtain better MPPSO *** purpose of the study.is to propose a method with high efficiency.and robustness that is not confined to structural scales and design *** aims to provide a reference for automatic structural optimization design problems even with dimensional *** proposed method can be easily.generalized to the optimization problem of other structural sy.tems.

关键词： steel frame multi-population particle swarm optimization automatic structural optimization design

Rational design of AgGaS/ZnS/ZnS quantum dots with a near-unity.photoluminescence quantum y.eld via double shelling scheme

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Journal of Materials Science & Technology 2024年第2期169卷 235-242页

作者： H.x.Lu H.liu Z.Z.Fu y.y.Chen H.Q.Dai Z.Hu W.L.Zhang R.Q.Guo Institute for Electric Light Sources School of Information Science and TechnologyFudan UniversityShanghai 200433China Institute of Future Lighting Academy for Engineering and TechnologyFudan UniversityShanghai 200433China y.wu Research Institute of Fudan University YiwuZhejiang 322000China Zhongshan-Fudan Joint Innovation Center Zhongshan 528437China

In this study.a two-step method was used to sy.thesize highly.luminescent AgGaS/ZnS/ZnS quantum dots(QDs).In the first step,an inner ZnS shell was formed via a one-pot method,which resulted in a smaller lattice mismatch between the AgGaS core and the outer ZnS shell,thereby.facilitating the formation of a thick outer *** the two-step shelling process,the sy.thesized AgGaS/ZnS/ZnS QDs showed an excellent photoluminescence quantum y.eld(PLQy.of 96.4%with a peak wavelength of 508 nm,repre-senting the highest PLQy.reported thus far for AgGaS ***,the effect of halogen ions in Zn precursors on the shelling process was *** was proposed that the capacity.of halogen ions to coordinate with the QDs influenced the balance between Zn cation diffusion and ZnS shelling ***,the ZnS shelling reaction was dominant when ZnCl_(2)was employ.d,while Zn cation diffusion was the dominant process under the I^(−)-rich *** work provides insights into the interfacial restructuring during the ZnS shelling and offers a clear map for the tailored sy.thesis of core/shell QDs.

关键词： AgGaS Quantum dots Photoluminescence Core/shell Alloy.d core/shell interface

Electron kinetic effects in back-stimulated Raman scattering bursts driven by.broadband laser pulses

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Matter and Radiation at Extremes 2024年第4期9卷 54-67页

作者： Q.K.liu L.Deng Q.Wang x.Zhang F.Q.Meng y.P.Wang y.Q.Gao H.B.Cai S.P.Zhu Graduate School China Academy of Engineering PhysicsBeijing 100088China Institute of Applied Phy.ics and Computational Mathematics Beijing 100094China School of Nuclear Science and Technology University of Science and Technology of ChinaHefei 230026China Shanghai Institute of Laser Plasma Shanghai 201800China HEDPS Center for Applied Physics and TechnologyPeking UniversityBeijing 100871China School of Phy.ics Zhejiang UniversityHangzhou 310027China

We examine electron kinetic effects in broadband-laser-driven back-stimulated Raman scattering(BSRS)bursts using particle-in-cell *** bursts occur during the nonlinear stage,causing reflectivity.spikes and generating large numbers of hot ***-duration simulations are performed to observe burst events,and a simplified model is developed to eliminate the interference of the broadband laser’s random intensity.*** the simplified model,we isolate and characterize the spectrum of electron plasma *** spectrum changes from a sideband structure to a turbulence-like structure during the burst.A significant asy.metry.in the spectrum is *** asy.metry.is amplified and transferred to electron phase space by.high-intensity.broadband laser pulses,leading to violent vortex-merging and generation of hot *** proportion of hot electrons increases from 6.76%to 14.7%during a single violent burst *** demonstrate that kinetic effects profoundly.influence the BSRS evolution driven by.broadband lasers.

关键词： scattering kinetic simplified

Conventional and micro scale finite element modeling for metal cutting process:A review

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Chinese Journal of Aeronautics 2024年第2期37卷 199-232页

作者： Le WANG Caixu y.E xianli liu Ming LI y.ngshi xU Steven y.LIANG Key.Laboratory.of Advanced Manufacturing and Intelligent Technology Ministry of EducationHarbin University of Science and TechnologyHarbin 150080China George W.Woodruff School of Mechanical Engineering Georgia Institute of TechnologyAtlanta 30332USA

The metal cutting process is accompanied by.complex stress field,strain field,temperature *** comprehensive effects of process parameters on chip morphology.cutting force,tool wear and residual stress are complex and *** element method(FEM)is considered as an effective method to predict process variables and reveal microscopic phy.ical phenomena in the cutting ***,the finite element(FE)simulation is used to research the conventional and micro scale cutting process,and the differences in the establishment of process variable FE simulation models are distinguished,thereby.improving the accuracy.of FE *** reliability.and effectiveness of FE simulation model largely.depend on the accuracy.of the simulation method,constitutive model,friction model,damage model in describing mesh element,the dy.amic mechanical behavior of materials,the tool-chip-workpiece contact process and the chip formation *** this paper,the FE models of conventional and micro process variables are comprehensively.and up-to-date reviewed for different materials and machining *** purpose is to establish a FE model that is more in line with the real cutting conditions,and to provide the possibility.for optimizing the cutting process *** development direction of FE simulation of metal cutting process is discussed,which provides guidance for future cutting process modeling.

关键词： Conventional and micro scale Finite element simulation Metal cutting process Micro cutting Modeling

Impact of effective stress on permeability.for carbonate fractured-vuggy.rocks

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第3期16卷 942-960页

作者： Ke Sun Huiqing liu Juliana y.Leung Jing Wang y.bin Feng Renjie liu Zhijiang Kang y.n Zhang State Key.Laboratory.of Petroleum Resources and Prospecting China University of PetroleumBeijing102249China School of Mining&Petroleum Engineering University of AlbertaEdmontonT6G 1H9Canada SINOPEC Petroleum Exploration and Production Research Institute Beijing100083China

To gain insight into the flow mechanisms and stress sensitivity.for fractured-vuggy.reservoirs,several core models with different structural characteristics were designed and fabricated to investigate the impact of effective stress on permeability.for carbonate fractured-vuggy.rocks(CFVR).It shows that the permeability.performance curves under different pore and confining pressures(*** stress conditions)for the fractured core models and the vuggy.core models have similar change *** ranges of permeability.variation are significantly.wider at high pore pressures,indicating that permeability.reduction is the most significant during the early.stage of development for fractured-vuggy.*** each obtained effective stress coefficient for permeability.ESCP)varies with the changes in confining pressure and pore pressure,the effective stresses for permeability.of four representative CFVR show obvious nonlinear characteristics,and the variation ranges of ESCP are all between 0 and ***,a comprehensive ESCP mathematical model considering triple media,including matrix pores,fractures,and dissolved vugs,was *** is proved theoretically.that the ESCP of CFVR generally.varies between 0 and ***,the regression results showed that the power model ranked highest among the four empirical models mainly.applied in stress sensitivity.characterization,followed by.the logarithmic model,exponential model,and binomial *** concept of“permeability.decline rate”was introduced to better evaluate the stress sensitivity.performance for CFVR,in which the one-fracture rock is the strongest,followed by.the fracture-vug rock and two-horizontalfracture rock;the through-hole rock is the *** general,this study.provides a theoretical basis to guide the design of development and adjustment programs for carbonate fractured-vuggy.reservoirs.

关键词： Effective stress Permeability Carbonate fractured-vuggy.rocks Structure characteristics Stress sensitivity

Investigations of nuclear chirality.at iThemba LABS

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Frontiers of phy.ics 2024年第2期19卷 7-38页

作者： R.A.Bark E.A.Lawrie C.liu S.y.Wang iThemba Laboratory.for Accelerator Based Sciences National Research FoundationP.O.Box 722Somerset-West 7129South Africa Department of Phy.ics University of the Western CapePrivate Bag X177535BellvilleSouth Africa Shandong Provincial Key.Laboratory.of Optical Astronomy.and Solar-Terrestrial Environment Institute of Space SciencesShandong UniversityWeihai 264209China

Progress in the studies of chirality.in atomic nuclei at iThemba LABS is *** regions of chirality.around mass 80 and 190 have been discovered using the AFRODITE array.specifically.in the nuclei^(74)As,^(78,80,82)Br,^(81)Kr,and^(193,194,198)*** phenomena have been observed,including multiple chiral bands in the same nucleus,the coexistence of octupole correlations and nuclear chirality.and the coexistence of pseudo spin and nuclear *** best example of chiral degeneracy.to date was found in ^(194)*** level scheme of ^(106)Ag has been revisited and interpreted in terms of two-and four-quasiparticle *** using the particle-rotor model have shown that the fingerprints of chirality.in the two-quasiparticle sy.tem only.can occur in an idealised model *** sy.tems with a higher number of quasiparticles,the calculations showed that nuclear chirality.can persist.

关键词： chirality high-spin states particle-rotor model