期刊文献+
共找到58,907篇文章
< 1 2 250 >
每页显示 20 50 100
Adiabatic shear localization evolution for steel based on the Johnson-Cook model and gradient-dependent plasticity 被引量:4
1
作者 Xuebin Wang 《Journal of University of Science and Technology Beijing》 CSCD 2006年第4期313-318,共6页
Gradient-dependent plasticity is introduced into the phenomenological Johnson-Cook model to study the effects of strainhardening, strain rate sensitivity, thermal-softening, and microstructure. The microstructural eff... Gradient-dependent plasticity is introduced into the phenomenological Johnson-Cook model to study the effects of strainhardening, strain rate sensitivity, thermal-softening, and microstructure. The microstructural effect (interactions and interplay among microstructures) due to heterogeneity of texture plays an important role in the process of development or evolution of an adiabatic shear band with a certain thickness depending on the grain diameter. The distributed plastic shear strain and deformation in the shear band are derived and depend on the critical plastic shear strain corresponding to the peak flow shear stress, the coordinate or position, the internal length parameter, and the average plastic shear strain or the flow shear stress. The critical plastic shear strain, the distributed plastic shear strain, and deformation in the shear band are numerically predicted for a kind of steel deformed at a constant shear strain rate. Beyond the peak shear stress, the local plastic shear strain in the shear band is highly nonuniform and the local plastic shear deformation in the band is highly nonlinear. Shear localization is more apparent with the increase of the average plastic shear strain. The calculated distributions of the local plastic shear strain and deformation agree with the previous numerical and experimental results. 展开更多
关键词 adiabatic shear band STEEL STRAIN-HARDENING gradient-dependent plasticity Johnson-Cook model
在线阅读 下载PDF
Dynamic analysis of fault rockburst based on gradient-dependent plasticity and energy criterion 被引量:17
2
作者 XuebinWang XiaobinYang +1 位作者 ZhihuiZhang YishanPan 《Journal of University of Science and Technology Beijing》 CSCD 2004年第1期5-9,共5页
Fault rockburst is treated as a strain localization problem under dynamicloading condition considering strain gradient and strain rate. As a kind of dynamic fracturephenomena, rockburst has characteristics of strain l... Fault rockburst is treated as a strain localization problem under dynamicloading condition considering strain gradient and strain rate. As a kind of dynamic fracturephenomena, rockburst has characteristics of strain localization, which is considered as aone-dimensional shear problem subjected to normal compressive stress and tangential shear stress.The constitutive relation of rock material is bilinear (elastic and strain softening) and sensitiveto shear strain rate. The solutions proposed based on gradient-dependent plasticity show thatintense plastic strain is concentrated in fault band and the thickness of the band depends on thecharacteristic length of rock material. The post-peak stiffness of the fault band was determinedaccording to the constitutive parameters of rock material and shear strain rate. Fault bandundergoing strain softening and elastic rock mass outside the band constitute a system and theinstability criterion of the system was proposed based on energy theory. The criterion depends onthe constitutive relation of rock material, the structural size and the strain rate. The staticresult regardless of the strain rate is the special case of the present analytical solution. Highstrain rate can lead to instability of the system. 展开更多
关键词 strain localization ROCKBURST plastic strain gradient criterion ofinstability strain rate fault band strain softening
在线阅读 下载PDF
Quantitative calculation for the dissipated energy of fault rock burst based on gradient-dependent plasticity 被引量:11
3
作者 Xuebin Wang Shuhong Dai Long Hai Department of Mechanics and Engineering Sciences, Liaoning Technical University, Fuxin 123000, China 《Journal of University of Science and Technology Beijing》 CSCD 2004年第3期197-201,共5页
The capacity of energy absorption by fault bands after rock burst wascalculated quantitatively according to shear stress-shear deformation curves considering theinteractions and interplaying among microstructures due ... The capacity of energy absorption by fault bands after rock burst wascalculated quantitatively according to shear stress-shear deformation curves considering theinteractions and interplaying among microstructures due to the heterogeneity of strain softeningrock materials. The post-peak stiffness of rock specimens subjected to direct shear was derivedstrictly based on gradient-dependent plasticity, which can not be obtained from the classicalelastoplastic theory. Analytical solutions for the dissipated energy of rock burst were proposedwhether the slope of the post-peak shear stress-shear deformation curve is positive or not. Theanalytical solutions show that shear stress level, confining pressure, shear strength, brittleness,strain rate and heterogeneity of rock materials have important influence on the dissipated energy.The larger value of the dissipated energy means that the capacity of energy dissipation in the formof shear bands is superior and a lower magnitude of rock burst is expected under the condition ofthe same work done by external shear force. The possibility of rock burst is reduced for a lowersoftening modulus or a larger thickness of shear bands. 展开更多
关键词 rock burst HETEROGENEITY dissipated energy plastic strain gradient post-peak stiffness characteristic length fault band strain softefiing
在线阅读 下载PDF
Calculation of temperature distribution in adiabatic shear band based on gradient-dependent plasticity 被引量:8
4
作者 王学滨 《中国有色金属学会会刊:英文版》 CSCD 2004年第6期1062-1067,共6页
A method for calculation of temperature distribution in adiabatic shear band is proposed in terms of gradient-dependent plasticity where the characteristic length describes the interactions and interplaying among micr... A method for calculation of temperature distribution in adiabatic shear band is proposed in terms of gradient-dependent plasticity where the characteristic length describes the interactions and interplaying among microstructures. First, the increment of the plastic shear strain distribution in adiabatic shear band is obtained based on gradient-dependent plasticity. Then, the plastic work distribution is derived according to the current flow shear stress and the obtained increment of plastic shear strain distribution. In the light of the well-known assumption that 90% of plastic work is converted into the heat resulting in increase in temperature in adiabatic shear band, the increment of the temperature distribution is presented. Next, the average temperature increment in the shear band is calculated to compute the change in flow shear stress due to the thermal softening effect. After the actual flow shear stress considering the thermal softening effect is obtained according to the Johnson-Cook constitutive relation, the increment of the plastic shear strain distribution, the plastic work and the temperature in the next time step are recalculated until the total time is consumed. Summing the temperature distribution leads to rise in the total temperature distribution. The present calculated maximum temperature in adiabatic shear band in titanium agrees with the experimental observations. Moreover, the temperature profiles for different flow shear stresses are qualitatively consistent with experimental and numerical results. Effects of some related parameters on the temperature distribution are also predicted. 展开更多
关键词 温度分布 绝热剪切带 应力定位 金相学 计算方法
在线阅读 下载PDF
Analysis of localized shear deformation of ductile metal based on gradient-dependent plasticity 被引量:10
5
作者 王学滨 代树红 +1 位作者 海龙 潘一山 《中国有色金属学会会刊:英文版》 CSCD 2003年第6期1348-1353,共6页
Shear localization in linear strain softening heterogeneous material under simple shear was investigated analytically. The closed-form solutions obtained based on gradient plasticity theory considering interactions an... Shear localization in linear strain softening heterogeneous material under simple shear was investigated analytically. The closed-form solutions obtained based on gradient plasticity theory considering interactions and interplaying among microstructures due to heterogeneity of metal material show that in the normal direction of shear band, elastic shear displacement is linear; while plastic and total shear displacement are non-linear. Elastic shear strain in the band is uniform and the non-uniformity of total shear displacement stems from localized plastic shear displacement. In the center of the band, plastic and total shear displacement all reach their maximum values. In strain-softening process, elastic displacement decreases as flow shear stress decreases. Contrarily, plastic and total shear displacement increase and manifest shear localization occurs progressively. Under the same shear stress level, plastic and total shear displacement increase as strain softening modulus and elastic shear modulus decrease. The present analytical solutions were compared with many experimental results and the agreement is good. 展开更多
关键词 延性金属 局部剪切变形 显微结构 可塑性
在线阅读 下载PDF
Revisiting Nonlinear Modelling Approaches for Existing RC Structures:Lumped vs.Distributed Plasticity
6
作者 Hüseyin Bilgin Bredli Plaku 《Structural Durability & Health Monitoring》 2026年第1期70-85,共16页
Nonlinear static procedures are widely adopted in structural engineering practice for seismic performance assessment due to their simplicity and computational efficiency.However,their reliability depends heavily on ho... Nonlinear static procedures are widely adopted in structural engineering practice for seismic performance assessment due to their simplicity and computational efficiency.However,their reliability depends heavily on how the nonlinear behaviour of structural components is represented.The recent earthquakes in Albania(2019)and Türkiye(2023)have underscored the need for accurate assessment techniques,particularly for older reinforced concrete buildings with poor detailing.This study quantifies the discrepancies between default and user-defined component modelling in pushover analysis of pre-modern reinforced concrete structures,analysing two representative low-and mid-rise reinforced concrete frame buildings.The lumped plasticity approach incorporates moment-rotation relationships derived from actual member properties and reinforcement configurations,while the distributed plasticity approach uses software-generated default properties based on modern codes.Results show that the distributed plasticity models systematically overestimate both the strength and the deformation capacity by up to 35%compared to lumped plasticity models,especially in buildings with poor detailing and low concrete strength.These findings demonstrate that default software procedures,widely used in practice but not validated for pre-modern structures,produce dangerously unconservative seismic performance estimates.The study provides quantitative evidence of the critical need for tailored modelling strategies that reflect the actual conditions of the existing building stock. 展开更多
关键词 Reinforced concrete frames seismic assessment pushover analysis lumped plasticity distributed plasticity
在线阅读 下载PDF
Neuronal plasticity and its role in Alzheimer's disease and Parkinson's disease
7
作者 Israt Jahan Mohammad Harun-Ur-Rashid +4 位作者 MdAminul Islam Farhana Sharmin Soad K.Al Jaouni Abdullah M.Kaki Samy Selim 《Neural Regeneration Research》 2026年第1期107-125,共19页
Neuronal plasticity,the brain's ability to adapt structurally and functionally,is essential for learning,memory,and recovery from injuries.In neurodegenerative diseases such as Alzheimer's disease and Parkinso... Neuronal plasticity,the brain's ability to adapt structurally and functionally,is essential for learning,memory,and recovery from injuries.In neurodegenerative diseases such as Alzheimer's disease and Parkinson's disease,this plasticity is disrupted,leading to cognitive and motor deficits.This review explores the mechanisms of neuronal plasticity and its effect on Alzheimer's disease and Parkinson's disease.Alzheimer's disease features amyloid-beta plaques and tau tangles that impair synaptic function,while Parkinson's disease involves the loss of dopaminergic neurons affecting motor control.Enhancing neuronal plasticity offers therapeutic potential for these diseases.A systematic literature review was conducted using databases such as PubMed,Scopus,and Google Scholar,focusing on studies of neuronal plasticity in Alzheimer's disease and Parkinson's disease.Data synthesis identified key themes such as synaptic mechanisms,neurogenesis,and therapeutic strategies,linking molecular insights to clinical applications.Results highlight that targeting synaptic plasticity mechanisms,such as long-term potentiation and long-term depression,shows promise.Neurotrophic factors,advanced imaging techniques,and molecular tools(e.g.,clustered regularly interspaced short palindromic repeats and optogenetics)are crucial in understanding and enhancing plasticity.Current therapies,including dopamine replacement,deep brain stimulation,and lifestyle interventions,demonstrate the potential to alleviate symptoms and improve outcomes.In conclusion,enhancing neuronal plasticity through targeted therapies holds significant promise for treating neurodegenerative diseases.Future research should integrate multidisciplinary approaches to fully harness the therapeutic potential of neuronal plasticity in Alzheimer's disease and Parkinson's disease. 展开更多
关键词 Alzheimer's disease long-term depression long-term potentiation NEUROINFLAMMATION neuronal plasticity Parkinson's disease synaptic plasticity
暂未订购
Frontal synaptic plasticity:A new key to homeostatic sleep regulation
8
作者 Yusuke Iino Shoi Shi 《Neural Regeneration Research》 2026年第6期2313-2314,共2页
Sleep is a fundamental biological process essential for maintaining brain function,cognitive performance,and overall health.Despite over a century of research,the mechanisms underlying sleep homeostasis-the process by... Sleep is a fundamental biological process essential for maintaining brain function,cognitive performance,and overall health.Despite over a century of research,the mechanisms underlying sleep homeostasis-the process by which the need for sleep accumulates during wakefulness and dissipates during sleep-remain incompletely understood.This article explores the latest advancements in sleep research,focusing on the role of synaptic plasticity in sleep homeostasis,as illuminated by Sawada et al.(2024). 展开更多
关键词 homeostatic sleep sleep regulation brain function cognitive performance sleep homeostasis synaptic plasticity frontal synaptic plasticity
暂未订购
Monocyte Phenotypic Plasticity in Peripheral Artery Disease:From Pathophysiology to Therapeutic Targets
9
作者 Gizem Kaynar Beyaz Ahmet Kirbas Sevgi Kalkanli Tas 《BIOCELL》 2026年第1期130-153,共24页
Peripheral artery disease(PAD)remains a significant global health issue,with current treatments primarily focused on relieving symptoms and addressingmacrovascular issues.However,critical immunoinflammatory mechanisms... Peripheral artery disease(PAD)remains a significant global health issue,with current treatments primarily focused on relieving symptoms and addressingmacrovascular issues.However,critical immunoinflammatory mechanisms are often overlooked.Recent evidence suggests that monocyte phenotypic plasticity plays a central role in PAD development,affecting atherogenesis,plaque progression,ischemia-reperfusion injury,and chronic ischemic remodeling.This narrative review aims to summarize the latest advances(2023-2025)in understanding monocyte diversity,functional states,and their changes throughout different stages of PAD.We discuss both established and emerging biomarkers,such as circulating monocyte subset proportions,functional assays,immune checkpoint expression,and multi-omics signatures,highlighting their potential for prognosis and the challenges in translating them to clinical practice.We also present a stage-specific approach to mapping out potential therapies,linking monocyte phenotypes to molecular targets and possible interventions.Additionally,we address regulatory,economic,and implementation considerations for applying these findings in a clinical setting.The goal of this review is to facilitate the development of targeted immunomodulatory strategies to improve limb and cardiovascular outcomes in PAD by combining mechanistic understanding with therapeutic innovation. 展开更多
关键词 Peripheral artery disease MONOCYTES phenotypic plasticity IMMUNOMODULATION therapeutic targets
暂未订购
Brain structural plasticity in large-brained mammals:Not only narrowing roads
10
作者 Marco Ghibaudi Alessandro Zanone Luca Bonfanti 《Neural Regeneration Research》 2026年第5期1669-1680,共12页
The capacity of the central nervous system for structural plasticity and regeneration is commonly believed to show a decreasing progression from“small and simple”brains to the larger,more complex brains of mammals.H... The capacity of the central nervous system for structural plasticity and regeneration is commonly believed to show a decreasing progression from“small and simple”brains to the larger,more complex brains of mammals.However,recent findings revealed that some forms of neural plasticity can show a reverse trend.Although plasticity is a well-preserved,transversal feature across the animal world,a variety of cell populations and mechanisms seem to have evolved to enable structural modifications to take place in widely different brains,likely as adaptations to selective pressures.Increasing evidence now indicates that a trade-off has occurred between regenerative(mostly stem cell–driven)plasticity and developmental(mostly juvenile)remodeling,with the latter primarily aimed not at brain repair but rather at“sculpting”the neural circuits based on experience.In particular,an evolutionary trade-off has occurred between neurogenic processes intended to support the possibility of recruiting new neurons throughout life and the different ways of obtaining new neurons,and between the different brain locations in which plasticity occurs.This review first briefly surveys the different types of plasticity and the complexity of their possible outcomes and then focuses on recent findings showing that the mammalian brain has a stem cell–independent integration of new neurons into pre-existing(mature)neural circuits.This process is still largely unknown but involves neuronal cells that have been blocked in arrested maturation since their embryonic origin(also termed“immature”or“dormant”neurons).These cells can then restart maturation throughout the animal's lifespan to become functional neurons in brain regions,such as the cerebral cortex and amygdala,that are relevant to high-order cognition and emotions.Unlike stem cell–driven postnatal/adult neurogenesis,which significantly decreases from small-brained,short-living species to large-brained ones,immature neurons are particularly abundant in large-brained,long-living mammals,including humans.The immature neural cell populations hosted in these complex brains are an interesting example of an“enlarged road”in the phylogenetic trend of plastic potential decreases commonly observed in the animal world.The topic of dormant neurons that covary with brain size and gyrencephaly represents a prospective turning point in the field of neuroplasticity,with important translational outcomes.These cells can represent a reservoir of undifferentiated neurons,potentially granting plasticity within the high-order circuits subserving the most sophisticated cognitive skills that are important in the growing brains of young,healthy individuals and are frequently affected by debilitating neurodevelopmental and degenerative disorders. 展开更多
关键词 adult neurogenesis AMYGDALA brain plasticity cerebral cortex comparative approach evolution immature neurons
暂未订购
Xijiaqi Formula attenuates cognitive dysfunction by inhibiting neuroinflammation and promoting neuroplasticity in rats with chronic heart failure
11
作者 Jie Chen Xuefen Wu +8 位作者 Qian Zhang Hongcai Shang Wanting Li Linnan Zhou Xinyu Chu Guiyang Xia Huan Xia Xiaohong Wei Sheng Lin 《Chinese Journal of Natural Medicines》 2026年第1期73-88,共16页
Chronic heart failure(CHF)impairs cognitive function.Xijiaqi Formula(XJQ),a traditional Chinese medicine(TCM)used clinically to treat CHF,demonstrates potential for improving cognition in CHF patients.However,its prec... Chronic heart failure(CHF)impairs cognitive function.Xijiaqi Formula(XJQ),a traditional Chinese medicine(TCM)used clinically to treat CHF,demonstrates potential for improving cognition in CHF patients.However,its precise mechanism in treating post-CHF cognitive dysfunction remains unclear.This study systematically investigates XJQ’s effects on post-CHF cognitive dysfunction and the underlying mechanisms.The components of XJQ were identified through liquid chromatography-mass spectrometry.CHF was induced in rats via ligation of the left anterior descending coronary artery,followed by six weeks of XJQ treatment.Cardiac function was evaluated through echocardiography and hemodynamic parameters,while cognitive function was assessed using Morris water maze(MWM)and open field tests(OFT).XJQ treatment enhanced both cardiac and cognitive functions in CHF rats.Network pharmacology identified 12 core active components of XJQ and indicated its effect on cognitive dysfunction involved regulating synapses,inflammation,and phosphodiesterase 4(PDE4)-dependent cyclic adenosine monophosphate(cAMP)signaling.XJQ inhibited microglial and astrocyte activation,decreased proinflammatory cytokines,and mitigated neuronal damage.Notably,XJQ promoted synaptic repair and dendritic growth by downregulating PDE4 and upregulating cAMP,protein kinase A(PKA),cAMP-response element binding protein(CREB),brain-derived neurotrophic factor(BDNF),PSD95,and synapsin I levels.Molecular docking and Bio-layer interferometry assays confirmed direct binding of quercetin,kaempferol,isorhamnetin,and darutoside to PDE4.In conclusion,XJQ alleviates neuroinflammation and enhances synaptic plasticity to improve cognitive dysfunction in CHF rats via the PDE4/cAMP/PKA/CREB signaling pathway.These findings provide valuable insight into the heart-brain axis. 展开更多
关键词 Xijiaqi Formula Cognitive dysfunction Chronic heart failure Synaptic plasticity NEUROINFLAMMATION PDE4
原文传递
Plasticity meets regeneration during innate spinal cord repair
12
作者 Amruta Tendolkar Mayssa H.Mokalled 《Neural Regeneration Research》 2026年第3期1136-1137,共2页
Regenerative capacity of the central nervous system(CNS)is unevenly distributed among vertebrates.While most mammalian species including humans elicit limited repair following CNS injury or disease,highly regenerative... Regenerative capacity of the central nervous system(CNS)is unevenly distributed among vertebrates.While most mammalian species including humans elicit limited repair following CNS injury or disease,highly regenerative vertebrates including urodele amphibians and teleost fish spontaneously reverse CNS damage.Teletost zebrafish(danio rerio)are tropical freshwater fish that proved to be an excellent vertebrate model of successful CNS regeneration.Differential neuronal,glial,and immune injury responses underlie disparate injury outcomes between highly regenerative zebrafish and poorly regenerative mammals.This article describes complications associated with neuronal repair following spinal cord injury(SCI)in poorly regenerative mammals and highlights intersecting modes of plasticity and regeneration in highly regenerative zebrafish(Figures 1 and 2).Comparative approaches evaluating immunoglial SCI responses were recently reviewed elsewhere(Reyes and Mokalled,2024). 展开更多
关键词 urodele amphibians central nervous system central nervous system cns REGENERATION vertebrate model plasticity vertebrates teleost fish
暂未订购
A peridynamics modeling approach for pre-cracked rock cracking processes under impact by integrating Drucker-Prager plasticity model and efficient contact model
13
作者 Jingzhi Tu Nengxiong Xu Gang Mei 《Journal of Rock Mechanics and Geotechnical Engineering》 2026年第1期179-195,共17页
In rock engineering,natural cracks in rock masses subjected to external loads tend to initiate and propagate,leading to potential safety hazards.To investigate the effect of cracking behavior on the mechanical propert... In rock engineering,natural cracks in rock masses subjected to external loads tend to initiate and propagate,leading to potential safety hazards.To investigate the effect of cracking behavior on the mechanical properties of rocks,the cracking processes of pre-cracked rocks have been extensively studied using numerical modeling methods.The peridynamics(PD)exhibits advantages over other numerical methods due to the absence of the requirements for remeshing and external crack growth criterion.However,for modeling pre-cracked rock cracking processes under impact,current PD implementations lack generally applicable rock constitutive models and impact contact models,which leads to difficulties in determining rock material parameters and efficiently calculating impact loads.This paper proposes a non-ordinary state-based peridynamics(NOSBPD)modeling method integrating the Drucker-Prager(DP)plasticity model and an efficient contact model to address the above problems.In the proposed method,the Drucker-Prager plasticity model is integrated into the NOSBPD,thereby equipping NOSBPD with the capability to accurately characterize the nonlinear stress-strain relationship inherent in rocks.An efficient contact model between particles and meshes is designed to calculate the impact loads,which is essentially a coupling method of PD with the finite element method(FEM).The effectiveness of the proposed NOSBPD modeling method is verified by comparison with other numerical methods and experiments.Experimental results indicate that the proposed method can effectively and accurately predict the 3D cracking processes of pre-cracked cracks under impact loading,and the maximum principal stress is the key driver behind wing crack formation in pre-cracked rocks. 展开更多
关键词 Pre-cracked rocks Cracking processes Non-ordinary state-based peridynamics (NOSBPD) Drucker-Prager plasticity model Efficient contact model
在线阅读 下载PDF
Engineered peptides bolster plant plasticity
14
作者 Ziyao Hu Langrang Zhang +1 位作者 Huibin Han Guodong Wang 《Journal of Integrative Plant Biology》 2026年第1期13-16,共4页
Signaling peptides are known for their prominent roles in plant growth, development, and environmental adaptation(Zhang et al., 2025). However, their extremely low natural abundance and highly dynamic expression patte... Signaling peptides are known for their prominent roles in plant growth, development, and environmental adaptation(Zhang et al., 2025). However, their extremely low natural abundance and highly dynamic expression patterns pose significant technical challenges to extract sufficient amounts with good purity for biological studies and practical applications.Consequently, chemical synthesis and microbial systems offer attractive alternatives to obtain potent peptides at higher quantities and purity. Incorporating modifications or substitutions, chemically synthetic approaches enable the creation of more effective engineered peptides such as agonists,antagonists, chemically modified peptides, or peptide-like molecules with novel functions compared to native peptides. 展开更多
关键词 chemical synthesis plant growth plant development biological studies plant plasticity microbial systems engineered peptides signaling peptides
原文传递
Unveiling the microscopic origins of dual-phase HfTaC_(2)/W ceramics with enhanced plasticity
15
作者 Changxing ZHANG Ke CAO +7 位作者 Junhui LUO Xiaofei ZHU Junkai LIU Ying HAN Ran HE Qian LI Li YANG Yichun ZHOU 《Science China(Technological Sciences)》 2026年第3期126-136,共11页
Hf xTa 1-xC-based ceramics exhibit exceptional thermodynamic stability under extreme temperatures. However, their intrinsic brittleness raises significant concerns about their safe service in extreme environments. Her... Hf xTa 1-xC-based ceramics exhibit exceptional thermodynamic stability under extreme temperatures. However, their intrinsic brittleness raises significant concerns about their safe service in extreme environments. Here, we designed and fabricated HfTaC/W_(2) dual-phase ceramics with robust interface bonding through induction plasma spheroidization. During in situ transmission electron microscopy(TEM) mechanical testing, the dual-phase ceramics exhibited plastic deformation with a fracture strength of(7.6 ± 1.2) GPa and a strain of 23.8% ± 0.18% in nanopillar compression, and a fracture strain of 6.2% under tensile loading. The mechanism of plastic deformation in both compression and tensile tests is attributed to the interactions between dislocations and dual-phase interfaces, as well as the dislocation movement inside the W phase. Thus, our work demonstrates the enhanced plasticity of dual-phase HfTaC_(2)/W with a W network embedded in the HfTaC_(2) matrix than singlephase HfTaC_(2) and provides a paradigm for the development of advanced ceramics that combine strength with enhanced ductility for both functional and structural applications. 展开更多
关键词 HfTaC_(2)/W dual-phase ceramics in situ TEM heterogeneous interface dislocation-induced plasticity
原文传递
A Temperature-Indexed Concrete Damage Plasticity Model Incorporating Bond-Slip Mechanism for Thermo-Mechanical Analysis of Reinforced Concrete Structures
16
作者 Wu Feng Tengku Anita Raja Hussin Xu Yang 《Structural Durability & Health Monitoring》 2026年第1期216-234,共19页
This study investigates the thermo–mechanical behavior of C40 concrete and reinforced concrete subjected to elevated temperatures up to 700℃by integrating experimental testing and advanced numerical modeling.A tempe... This study investigates the thermo–mechanical behavior of C40 concrete and reinforced concrete subjected to elevated temperatures up to 700℃by integrating experimental testing and advanced numerical modeling.A temperature-indexed Concrete Damage Plasticity(CDP)framework incorporating bond–slip effects was developed in Abaqus to capture both global stress–strain responses and localized damage evolution.Uniaxial compression tests on thermally exposed cylinders provided residual strength data and failure observations for model calibration and validation.Results demonstrated a distinct two-stage degradation regime:moderate stiffness and strength reduction up to~400℃,followed by sharp deterioration beyond 500℃–600℃,with residual capacity at 700℃reduced to~20%–25%of the ambient value.Strain–damage analyses revealed the formation of a peripheral tensile strain band,which thickened and propagated inward with increasing temperature,governing crack initiation and cover spalling.Supplemental analyses highlighted that transverse reinforcement improved ductility and damage distribution at moderate temperatures(~300℃),but bond deterioration and steel softening beyond~600℃substantially diminished confinement effectiveness.The proposed CDP model accurately reproduced experimental stress–strain curves(R^(2)≈0.94–0.98 up to 600℃;≈0.90 at 700℃),with peak stress errors within 7%–10%and energy absorption captured within~12%.These findings confirm the robustness of the temperature-indexed CDP framework for simulating fire-damaged reinforced concrete and provide practical guidelines for post-fire assessment,spalling detection,and fire-resilient design of structural members. 展开更多
关键词 Thermo-mechanical coupling high temperature concrete damage plasticity(CDP) BOND-SLIP residual strength fire resistance spalling prediction structural safety assessment
在线阅读 下载PDF
Differential plasticity of excitatory and inhibitory reticulospinal fibers after spinal cord injury:Implication for recovery
17
作者 Rozaria Jeleva Carmen Denecke Muhr +1 位作者 Alina P.Liebisch Florence M.Bareyre 《Neural Regeneration Research》 2026年第5期2011-2020,共10页
The remodeling of axonal connections following injury is an important feature driving functional recovery.The reticulospinal tract is an interesting descending motor tract that contains both excitatory and inhibitory ... The remodeling of axonal connections following injury is an important feature driving functional recovery.The reticulospinal tract is an interesting descending motor tract that contains both excitatory and inhibitory fibers.While the reticulospinal tract has been shown to be particularly prone to axonal growth and plasticity following injuries of the spinal cord,the differential capacities of excitatory and inhibitory fibers for plasticity remain unclear.As adaptive axonal plasticity involves a sophisticated interplay between excitatory and inhibitory input,we investigated in this study the plastic potential of glutamatergic(vGlut2)and GABAergic(vGat)fibers originating from the gigantocellular nucleus and the lateral paragigantocellular nucleus,two nuclei important for locomotor function.Using a combination of viral tracing,chemogenetic silencing,and AI-based kinematic analysis,we investigated plasticity and its impact on functional recovery within the first 3 weeks following injury,a period prone to neuronal remodeling.We demonstrate that,in this time frame,while vGlut2-positive fibers within the gigantocellular and lateral paragigantocellular nuclei rewire significantly following cervical spinal cord injury,vGat-positive fibers are rather unresponsive to injury.We also show that the acute silencing of excitatory axonal fibers which rewire in response to lesions of the spinal cord triggers a worsening of the functional recovery.Using kinematic analysis,we also pinpoint the locomotion features associated with the gigantocellular nucleus or lateral paragigantocellular nucleus during functional recovery.Overall,our study increases the understanding of the role of the gigantocellular and lateral paragigantocellular nuclei during functional recovery following spinal cord injury. 展开更多
关键词 GABAergic(vGat)fibers gait features glutamatergic(vGlut2)fibers plasticity recovery of function reticulospinal tract spinal cord injury
暂未订购
INVESTIGATION ON GRADIENT-DEPENDENT NONLOCAL CONSTITUTIVE MODELS FOR ELASTO-PLASTICITY COUPLED WITH DAMAGE 被引量:1
18
作者 沈新普 沈国晓 +1 位作者 陈立新 杨璐 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2005年第2期218-233,共16页
Firstly, typical) gradient-dependent nonlocal inelastic models were briefly reviewed. Secondly, based on the principle of ‘gradient-dependent energy dissipation', a gradient-dependent constitutive model for plast... Firstly, typical) gradient-dependent nonlocal inelastic models were briefly reviewed. Secondly, based on the principle of ‘gradient-dependent energy dissipation', a gradient-dependent constitutive model for plasticity coupled with isotropic damage was presented in the framework of continuum thermodynamics. Numerical scheme for calculation of Laplacian term of damage field with the numerical results obtained by FEM calculation was proposed. Equations have been presented on the basis of Taylor series for both 2-dimensional and 3-dimensional cases, respectively. Numerical results have indicated the validity of the proposed gradient-dependent model and corresponding numerical scheme. 展开更多
关键词 DAMAGE plasticity NONLOCAL constitutive model gradient-dependent
在线阅读 下载PDF
Microstructural evolution during the progressive transformation-induced plasticity effect in a Fe-0.1C-5Mnmedium manganese steel 被引量:1
19
作者 Mei Zhang Wenhao Li +3 位作者 Yangfei Chen Yang Jiang Xiaofei Guo Han Dong 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS 2025年第2期369-379,共11页
The microstructural evolution of a cold-rolled and intercritical annealed medium-Mn steel(Fe-0.10C-5Mn)was investigated during uniaxial tensile testing.In-situ observations under scanning electron microscopy,transmiss... The microstructural evolution of a cold-rolled and intercritical annealed medium-Mn steel(Fe-0.10C-5Mn)was investigated during uniaxial tensile testing.In-situ observations under scanning electron microscopy,transmission electron microscopy,and X-ray diffraction analysis were conducted to characterize the progressive transformation-induced plasticity process and associated fracture initiation mechanisms.These findings were discussed with the local strain measurements via digital image correlation.The results indicated that Lüders band formation in the steel was limited to 1.5%strain,which was mainly due to the early-stage martensitic phase transformation of a very small amount of the less stable large-sized retained austenite(RA),which led to localized stress concentrations and strain hardening and further retardation of yielding.The small-sized RA exhibited high stability and progressively transformed into martensite and contributed to a stably extended Portevin-Le Chatelier effect.The volume fraction of RA gradually decreased from 26.8%to 8.2%prior to fracture.In the late deformation stage,fracture initiation primarily occurred at the austenite/martensite and ferrite/martensite interfaces and the ferrite phase. 展开更多
关键词 medium-Mn steel retained austenite progressive transformation-induced plasticity effect local strain fracture initiation
在线阅读 下载PDF
Recent Advances in the Molecular Mechanisms of Ocular Dominance Plasticity in the Visual Cortex 被引量:2
20
作者 Yanglin Qin Wei Wang +1 位作者 Yu Gu Xuefeng Shi 《Neuroscience Bulletin》 2025年第9期1645-1655,共11页
The visual cortex is an essential part of the brain for processing visual information.It exhibits structural and functional plasticity,which is crucial for adapting to complex visual environments.The quintessential ma... The visual cortex is an essential part of the brain for processing visual information.It exhibits structural and functional plasticity,which is crucial for adapting to complex visual environments.The quintessential manifestation of visual cortical plasticity is ocular dominance plasticity during the critical period,which involves numerous cellular and molecular events.While previous studies have emphasized the role of visual cortical neurons and their associated functional molecules in visual plasticity,recent findings have revealed that structural factors such as the extracellular matrix and glia are also involved.Investigating how these molecules interact to form a complex network that facilitates plasticity in the visual cortex is crucial to our understanding of the development of the visual system and the advancement of therapeutic strategies for visual disorders like amblyopia. 展开更多
关键词 Visual cortex plasticity Visual experience Development Molecular mechanisms
原文传递
上一页 1 2 250 下一页 到第
使用帮助 返回顶部