Programmable/reprogrammable magneto-responsive composites(MRCs)are highly desirable for applications in soft robotics,morphable actuators,and biomedical devices due to their capabilities of undergoing reversible,compl...Programmable/reprogrammable magneto-responsive composites(MRCs)are highly desirable for applications in soft robotics,morphable actuators,and biomedical devices due to their capabilities of undergoing reversible,complex,untethered,and rapid deformations.However,current MRC-based devices primarily rely on soft matrices,which revert to their original shapes and cease functioning when external magnetic fields are removed.Moreover,their magnetization programming,deformations,and functioning need to alternate between encoding and actuation platforms,limiting the adaptability and efficiency.Here,we present a reprogrammable magnetic shape-memory composite(RM-SMC)integrating a shape-memory polymer(SMP)skeleton with phase-transition magnetic microcapsules.High-intensity laser melts microcapsules for magnetic realignment under programmed fields,while low-intensity laser softens SMP for structural reconfiguration without compromising integrity.This dual-laser strategy facilitates in situ magnetization programming,shape morphing,and function execution within a single material system.Our innovative approach enables unique applications,including omnidirectional multi-degree-of-freedom actuators that can activate light switches,solar trackers that optimize energy capture,and adaptive impellers that modulate fluid pumping.By eliminating platform alternation and enabling shape/function retention post-actuation,the RM-SMC platform overcomes critical limitations in conventional MRCs,establishing a paradigm for multifunctional devices requiring persistent configuration control and field-independent operation.展开更多
BACKGROUND Mild cognitive impairment(MCI)is a high-risk precursor to Alzheimer’s disease characterized by declining memory or other progressive cognitive functions without compromising daily living abilities.AIM To i...BACKGROUND Mild cognitive impairment(MCI)is a high-risk precursor to Alzheimer’s disease characterized by declining memory or other progressive cognitive functions without compromising daily living abilities.AIM To investigate the efficacy of repetitive transcranial magnetic stimulation(rTMS)in patients with MCI.METHODS This retrospective analysis involved 180 patients with MCI who were admitted to The First Hospital of Shanxi Medical University from January 2021 to June 2023.Participants were allocated into the research(n=98,receiving rTMS)and control groups(n=82,receiving sham stimulation).Memory tests,cognitive function assessments,event-related potential–P300 tests,and electroencephalogram(EEG)examinations were conducted pre-treatment and post-treatment.Further,memory quotient(MQ),cognitive function scores,and EEG grading results were compared,along with adverse reaction incidences.RESULTS Pre-treatment MQ scores,long-term and short-term memory,as well as immediate memory scores,demonstrated no notable differences between the groups.Post-treatment,the research group exhibited significant increases in MQ scores,long-term memory,and short-term memory compared to baseline(P<0.05),with these improvements being statistically superior to those in the control group.However,immediate memory scores exhibited no significant change(P>0.05).Further,the research group demonstrated statistically better post-treatment scores on the Revised Wechsler Memory Scale than the control group.Furthermore,post-treatment P300 latency and amplitude improved significantly in the research group,surpassing the control group.EEG grading in the research group improved,and the incidence of adverse reactions was significantly lower than in the control group.CONCLUSION Patients with MCI receiving rTMS therapy demonstrated improved memory and cognitive functions and EEG grading and exhibited high safety with fewer adverse reactions.展开更多
As artificial intelligence and big data become increasingly prevalent, resistive random-access memory (RRAM) has become one of the most promising alternatives for storing massive amounts of data. In this study, we emp...As artificial intelligence and big data become increasingly prevalent, resistive random-access memory (RRAM) has become one of the most promising alternatives for storing massive amounts of data. In this study, we employed high-quality crystalline TiN/Al_(2)O_(3)/BaTiO_(3)/Pt RRAM with an optimized thin Al_(2)O_(3) interlayer around 12 nm thick prepared using atomic layer deposition since the thickness of the interlayer affects the memory window size. After insertion of the Al_(2)O_(3) interlayer, the novel RRAM exhibited outstanding uniform resistive switching voltage and the ON/OFF memory window drastically increased from 10 to 103 without any discernible decline in performance. Moreover, the low-resistance state and high-resistance state operating current values decreased by almost one order and three orders of magnitude, respectively, thereby decreasing the power consumption for the RESET and SET processes by more than three and almost one order of magnitude, respectively. The device also exhibits multilevel resistive switching behavior when varying the applied voltage. Finally, we also developed a 6 6 crossbar array which demonstrated consistent and reliable resistive switching behavior with minimal variation. Hence, our approach holds great promise for producing state-of-the-art non-volatile resistive switching devices.展开更多
Shape memory alloys(SMAs)and shape memory ceramics(SMCs)exhibit high recovery ability due to the martensitic transformation,which complicates the fracture mechanism of SMAs and SMCs.The phase field method,as a powerfu...Shape memory alloys(SMAs)and shape memory ceramics(SMCs)exhibit high recovery ability due to the martensitic transformation,which complicates the fracture mechanism of SMAs and SMCs.The phase field method,as a powerful numerical simulation tool,can efficiently resolve the microstructural evolution,multi-field coupling effects,and fracture behavior of SMAs and SMCs.This review begins by presenting the fundamental theoretical framework of the fracture phase field method as applied to SMAs and SMCs,covering key aspects such as the phase field modeling of martensitic transformation and brittle fracture.Subsequently,it systematically examines the phase field simulations of fracture behaviors in SMAs and SMCs,with particular emphasis on how crystallographic orientation,grain size,and grain boundary properties influence the crack propagation.Additionally,the interplay between martensite transformation and fracture mechanisms is analyzed to provide deeper insights into the material responses under mechanical loading.Finally,the review explores future prospects and emerging trends in phase field simulations of SMA and SMC fracture behavior,along with potential advancements in the fracture phase field method itself,including multi-physics coupling and enhanced computational efficiency for large-scale simulations.展开更多
At the beginning of the 20^(th)century,German scientist Richard Semon introduced the term'engram'to describe the neural substrate implicated in the processes of memory formation and retrieval[1].The trace of t...At the beginning of the 20^(th)century,German scientist Richard Semon introduced the term'engram'to describe the neural substrate implicated in the processes of memory formation and retrieval[1].The trace of the corresponding biophysical and biochemical changes in the brain responding to an external stimulus is called an engram,and understanding the physical manifestations of memory formation and recall remains a fundamental yet unresolved question[2].展开更多
This paper presents the development of a thermoplastic shape memory rubber that can be programmed at human body temperature for comfortable fitting applications.We hybridized commercially available thermoplastic rubbe...This paper presents the development of a thermoplastic shape memory rubber that can be programmed at human body temperature for comfortable fitting applications.We hybridized commercially available thermoplastic rubber(TPR)used in the footwear industry with un-crosslinked polycaprolactone(PCL)to create two samples,namely TP6040 and TP7030.The shape memory behavior,elasticity,and thermo-mechanical response of these rubbers were systematically investigated.The experimental results demonstrated outstanding shape memory performance,with both samples achieving shape fixity ratios(Rf)and shape recovery ratios(R_(r))exceeding 94%.TP6040 exhibited a fitting time of 80 s at body temperature(37℃),indicating a rapid response for shape fixing.The materials also showed good elasticity before and after programming,which is crucial for comfort fitting.These findings suggest that the developed shape memory thermoplastic rubber has potential applications in personalized comfort fitting products,offering advantages over traditional customization techniques in terms of efficiency and cost-effectiveness.展开更多
Computing-in-memory(CIM)has been a promising candidate for artificial-intelligent applications thanks to the absence of data transfer between computation and storage blocks.Resistive random access memory(RRAM)based CI...Computing-in-memory(CIM)has been a promising candidate for artificial-intelligent applications thanks to the absence of data transfer between computation and storage blocks.Resistive random access memory(RRAM)based CIM has the advantage of high computing density,non-volatility as well as high energy efficiency.However,previous CIM research has predominantly focused on realizing high energy efficiency and high area efficiency for inference,while little attention has been devoted to addressing the challenges of on-chip programming speed,power consumption,and accuracy.In this paper,a fabri-cated 28 nm 576K RRAM-based CIM macro featuring optimized on-chip programming schemes is proposed to address the issues mentioned above.Different strategies of mapping weights to RRAM arrays are compared,and a novel direct-current ADC design is designed for both programming and inference stages.Utilizing the optimized hybrid programming scheme,4.67×programming speed,0.15×power saving and 4.31×compact weight distribution are realized.Besides,this macro achieves a normalized area efficiency of 2.82 TOPS/mm2 and a normalized energy efficiency of 35.6 TOPS/W.展开更多
A Shape Memory Polymer Composite(SMPC)is developed by reinforcing an epoxy-based polymer with randomly oriented short glass fibers.Diverging from previous research,which primarily focused on the hot programming of sho...A Shape Memory Polymer Composite(SMPC)is developed by reinforcing an epoxy-based polymer with randomly oriented short glass fibers.Diverging from previous research,which primarily focused on the hot programming of short glass fiber-based SMPCs,this work explores the potential for programming below the glass transition temperature(Tg)for epoxy-based SMPCs.To mitigate the inherent brittleness of the SMPC during deformation,a linear polymer is incorporated,and a temperature between room temperature and Tg is chosen as the deformation temperature to study the shape memory properties.The findings demonstrate an enhancement in shape fixity and recovery stress,alongside a reduction in shape recovery,with the incorporation of short glass fibers.In addition to tensile properties,thermal properties such as thermal conductivity,specific heat capacity,and glass transition temperature are investigated for their dependence on fiber content.Microscopic properties,such as fiber-matrix adhesion and the dispersion of glass fibers,are examined through Scanning Electron Microscope imaging.The fiber length distribution and mean fiber lengths are also measured for different fiber fractions.展开更多
设计了一套存储器辐射效应远程在线测试系统,对一款磁阻随机存取存储器(Magnetoresistive Random Access Memory,MRAM)在不同工作模式下开展了电离总剂量和瞬态电离辐射效应实验研究,获得了以下研究结果:1)电离总剂量辐照实验中,在动态...设计了一套存储器辐射效应远程在线测试系统,对一款磁阻随机存取存储器(Magnetoresistive Random Access Memory,MRAM)在不同工作模式下开展了电离总剂量和瞬态电离辐射效应实验研究,获得了以下研究结果:1)电离总剂量辐照实验中,在动态读写模式下,首先出现的效应为电源电流显著增加,器件在30 krad(Si)时,出现了读数据错误;2)瞬态电离辐射辐照实验中,MRAM在静态加电模式和动态读数据模式未观测到数据或功能错误,但在动态写数据模式下出现数据写入失败的现象。初步分析认为写数据失败的原因可能是γ射线引起的PN结光电流形成电路全局光电流,造成MRAM电源波动,触发MRAM写保护有效。本文研究结果表明在总剂量与瞬态电离辐射环境下,MRAM会出现功能异常。MRAM的外围电路是其抗辐射性能的敏感薄弱环节。展开更多
The main purpose of this paper is to investigate the singularities of solutions to the single Tricomi equation with derivative term and combined memory term.In addition,the blow-up of the solution to the weakly couple...The main purpose of this paper is to investigate the singularities of solutions to the single Tricomi equation with derivative term and combined memory term.In addition,the blow-up of the solution to the weakly coupled system with memory term is also considered,where one is a power nonlinear term and the other is a derivative nonlinear term.Upper bound lifespan estimates of solution are obtained in the sub-critical by utilizing the test function method and iteration technique.The innovation of this paper focuses on the lifespan estimates of the solutions,which extends the well-known Strauss and Glassey conjectures.展开更多
The distinctive feature of the adaptive immune system is its ability to generate immunological memory that can provide defense against subsequent infections.In the case of antibody-mediated immune responses,this memor...The distinctive feature of the adaptive immune system is its ability to generate immunological memory that can provide defense against subsequent infections.In the case of antibody-mediated immune responses,this memory comes in two cellular forms:plasma cells(PCs)and memory B cells(MBCs).PCs protect against reinfection by constitutively producing antibodies.The presence of a diverse pool of MBCs,which can expand and differentiate into PCs in secondary immune responses,is thought to be particularly important for defense against new pathogen variants.Recent studies have shown that the MBC compartment is far more heterogeneous than previously anticipated.This heterogeneity,among other factors,is shaped by their developmental pathway(germinal center(GC)vs non-GC-derived MBCs),the duration and strength of antigenic stimulation,anatomical and microanatomical localization,and the timing of generation in ontogeny.Combinations of these“layers”of MBC identities can define MBCs’properties and their fate in recall responses.Here,we review the mechanisms underlying MBC differentiation,maintenance,and reactivation and explore how the layered identity of MBCs contributes to the functions of these cells.展开更多
Aerobic exercise facilitates synaptic plasticity,thereby improving cognitive functions such as learning and memory.The 5-hydroxytryptamine system has been indicated in these processes.5-Hydroxytryptamine type 3 recept...Aerobic exercise facilitates synaptic plasticity,thereby improving cognitive functions such as learning and memory.The 5-hydroxytryptamine system has been indicated in these processes.5-Hydroxytryptamine type 3 receptors are necessary for exercise-induced hippocampal neurogenesis.Some antipsychotic drugs with 5-hydroxytryptamine type 3 receptor antagonistic properties may impede the amelioration of cognitive impairment and hippocampal plasticity induced by exercise.However,the mechanisms underlying the facilitation of synaptic plasticity by aerobic exercise have not yet been elucidated.In this study,we found that 5-hydroxytryptamine type 3 receptors played an important role in aerobic exercise-mediated improvement of hippocampal-dependent spatial and exploratory memory in mice.While 5-hydroxytryptamine type 3 receptors did not affect baseline neurogenesis in the hippocampal dentate gyrus,5-hydroxytryptamine type 3 receptors were required for aerobic exercise-induced neurogenesis and astrocyte proliferation in this region.In addition,5-hydroxytryptamine type 3 receptors were crucial for maintaining long-term potentiation in the CA1,dentate gyrus,and CA3 regions of the hippocampus.The long-term potentiation changes induced by aerobic exercise in sub-regions of the hippocampus were heterogeneous:5-hydroxytryptamine type 3 receptors were essential for aerobic exercise to enhance long-term potentiation in the CA3,but not the CA1 or dentate gyrus,regions of the hippocampus.Furthermore,aerobic exercise up-regulated 5-hydroxytryptamine type 3 receptor expression and increased brain-derived neurotrophic factor release in the hippocampus in a 5-hydroxytryptamine type 3 receptor-dependent manner.These results suggest that aerobic exercise increases hippocampal dentate gyrus neurogenesis and astrocyte proliferation via the up-regulation of 5-hydroxytryptamine type 3 receptors,leading to more brain-derived neurotrophic factor production and release from these cells,which results in long-term potentiation facilitation in the hippocampal CA3 region and help improve memory.Our findings provide insight into the mechanisms by which physical activity enhances memory and may have implications for improving memory through modulating 5-hydroxytryptamine type 3 receptor.展开更多
With the acceleration of industrialization,the pollution problem of sulfur dioxide(SO_(2))emitted from coal-fired power plants has become increasingly severe.Although wet flue gas desulfurization(FGD)technology can re...With the acceleration of industrialization,the pollution problem of sulfur dioxide(SO_(2))emitted from coal-fired power plants has become increasingly severe.Although wet flue gas desulfurization(FGD)technology can remove about 95%of SO_(2),its high energy consumption and the corrosion risk of downstream equipment caused by residual SO_(2)(500–3000 ppm)still need to be addressed[1].Previous porous materials(such as MOFs)achieve selective adsorption of SO_(2) through open metal sites,M–OH sites or functional organic groups,but the problem of CO_(2) co-adsorption limits their practical application[2].In recent years,hydrogen-bonded organic frameworks(HOFs)have emerged as a research hotspot due to their reversible hydrogen-bonding networks and flexible structures[3],but their stability under extreme conditions and efficient separation performance still need to be improved[4].展开更多
Near-infrared(NIR)light-responsive shape memory polymers(SMPs)show great promise for biomedical applications,but conventional photothermal agents suffer from high cost,complex preparation,or poor biocompatibility,whil...Near-infrared(NIR)light-responsive shape memory polymers(SMPs)show great promise for biomedical applications,but conventional photothermal agents suffer from high cost,complex preparation,or poor biocompatibility,while lignin-based alternatives exhibit insufficient photothermal conversion efficiency.Herein,we developed a novel strategy to enhance photothermal performance of lignin through sequential demethylation modification and Fe^(3+)complexation for constructing NIR light responsive SMPs.Dealkaline lignin(DL)was first demethylated using iodocyclohexane to produce demethylated lignin(DDL)with increased catechol content,which was then incorporated into polycaprolactone-based polyurethane synthesis followed by Fe^(3+)complexation.Results showed that DDL-Fe^(3+)complexes have significantly enhanced photothermal conversion performance,and the resulting PU-DDL+Fe^(3+)polyurethane with 0.5 wt%DDL content demonstrated a temperature increases of 39.8℃under 0.33 W·cm-2808 nm NIR irradiation.This excellent photothermal performance enables the shape-fixed PU-DDL+Fe^(3+)polyurethane to rapidly recover to its initial shape under NIR light irradiation.Additionally,PU-DDL+Fe^(3+)polyurethane exhibits good mechanical properties and biocompatibility,demonstrating significant biomedical application potential.展开更多
The goal of this paper is to investigate the long-time dynamics of solutions to a Kirchhoff type suspension bridge equation with nonlinear damping and memory term.For this problem we establish the well-posedness and e...The goal of this paper is to investigate the long-time dynamics of solutions to a Kirchhoff type suspension bridge equation with nonlinear damping and memory term.For this problem we establish the well-posedness and existence of uniform attractor under some suitable assumptions on the nonlinear term g(u),the nonlinear damping f(u_(t))and the external force h(x,t).Specifically,the asymptotic compactness of the semigroup is verified by the energy reconstruction method.展开更多
GABA_(A) receptors containingα5-subunits(GABA_(A)R-α5)cluster at both extrasynaptic and synaptic locations,interacting with the scaffold proteins radixin and gephyrin,respectively,and the re-localization of GABA_(A...GABA_(A) receptors containingα5-subunits(GABA_(A)R-α5)cluster at both extrasynaptic and synaptic locations,interacting with the scaffold proteins radixin and gephyrin,respectively,and the re-localization of GABA_(A)R-α5 influences GABAergic transmission.Here,we found that when early spatial memory deficits occurred in aged mice at 24 h after sevoflurane anesthesia,there was a re-localization of GABA_(A)R-α5 that enhanced tonic inhibition and reduced the decay kinetics of miniature inhibitory postsynaptic currents in the hippocampal CA1 region.Mechanistically,increased phosphorylation of radixin at threonine 564(Thr564)mediates the re-localization of GABA_(A)R-α5.Acute treatment with the selective extrasynaptic GABA_(A)R-α5 antagonist S44819 restored the GABA_(A)R-α5-mediated inhibitory currents by reversing radixin phosphorylation-dependent GABA_(A)R-α5 re-localization,then improved the sevoflurane-induced spatial memory impairment in aged mice.Our results suggest that the localization of GABA_(A)R-α5 altered by sevoflurane is linked to unbalanced GABAergic transmission,which induces early memory impairment in aged mice.Modulating the GABA_(A)R-α5 localization might be a novel strategy to improve memory after sevoflurane exposure.展开更多
Oxide semiconductors(OSs),introduced by the Hosono group in the early 2000s,have evolved from display backplane materials to promising candidates for advanced memory and logic devices.The exceptionally low leakage cur...Oxide semiconductors(OSs),introduced by the Hosono group in the early 2000s,have evolved from display backplane materials to promising candidates for advanced memory and logic devices.The exceptionally low leakage current of OSs and compatibility with three-dimensional(3D)architectures have recently sparked renewed interest in their use in semiconductor applications.This review begins by exploring the unique material properties of OSs,which fundamentally originate from their distinct electronic band structure.Subsequently,we focus on atomic layer deposition(ALD),a core technique for growing excellent OS films,covering both basic and advanced processes compatible with 3D scaling.The basic surface reaction mechanisms—adsorption and reaction—and their roles in film growth are introduced.Furthermore,material design strategies,such as cation selection,crystallinity control,anion doping,and heterostructure engineering,are discussed.We also highlight challenges in memory applications,including contact resistance,hydrogen instability,and lack of p-type materials,and discuss the feasibility of ALD-grown OSs as potential solutions.Lastly,we provide an outlook on the role of ALD-grown OSs in memory technologies.This review bridges material fundamentals and device-level requirements,offering a comprehensive perspective on the potential of ALD-driven OSs for next-generation semiconductor memory devices.展开更多
基金supported by the National Natural Science Foundation of China(Nos.52075516,61927814,62325507,and 52122511)the National Key Research and Development Program of China(No.2021YFF0502700)+2 种基金the Major Scientific and Technological Projects in Anhui Province(202103a05020005,202203a05020014)the Students’Innovation and Entrepreneurship Foundation of USTC(CY2022G09)the Hefei Municipal Natural Science Foundation(No.HZR2450)。
文摘Programmable/reprogrammable magneto-responsive composites(MRCs)are highly desirable for applications in soft robotics,morphable actuators,and biomedical devices due to their capabilities of undergoing reversible,complex,untethered,and rapid deformations.However,current MRC-based devices primarily rely on soft matrices,which revert to their original shapes and cease functioning when external magnetic fields are removed.Moreover,their magnetization programming,deformations,and functioning need to alternate between encoding and actuation platforms,limiting the adaptability and efficiency.Here,we present a reprogrammable magnetic shape-memory composite(RM-SMC)integrating a shape-memory polymer(SMP)skeleton with phase-transition magnetic microcapsules.High-intensity laser melts microcapsules for magnetic realignment under programmed fields,while low-intensity laser softens SMP for structural reconfiguration without compromising integrity.This dual-laser strategy facilitates in situ magnetization programming,shape morphing,and function execution within a single material system.Our innovative approach enables unique applications,including omnidirectional multi-degree-of-freedom actuators that can activate light switches,solar trackers that optimize energy capture,and adaptive impellers that modulate fluid pumping.By eliminating platform alternation and enabling shape/function retention post-actuation,the RM-SMC platform overcomes critical limitations in conventional MRCs,establishing a paradigm for multifunctional devices requiring persistent configuration control and field-independent operation.
文摘BACKGROUND Mild cognitive impairment(MCI)is a high-risk precursor to Alzheimer’s disease characterized by declining memory or other progressive cognitive functions without compromising daily living abilities.AIM To investigate the efficacy of repetitive transcranial magnetic stimulation(rTMS)in patients with MCI.METHODS This retrospective analysis involved 180 patients with MCI who were admitted to The First Hospital of Shanxi Medical University from January 2021 to June 2023.Participants were allocated into the research(n=98,receiving rTMS)and control groups(n=82,receiving sham stimulation).Memory tests,cognitive function assessments,event-related potential–P300 tests,and electroencephalogram(EEG)examinations were conducted pre-treatment and post-treatment.Further,memory quotient(MQ),cognitive function scores,and EEG grading results were compared,along with adverse reaction incidences.RESULTS Pre-treatment MQ scores,long-term and short-term memory,as well as immediate memory scores,demonstrated no notable differences between the groups.Post-treatment,the research group exhibited significant increases in MQ scores,long-term memory,and short-term memory compared to baseline(P<0.05),with these improvements being statistically superior to those in the control group.However,immediate memory scores exhibited no significant change(P>0.05).Further,the research group demonstrated statistically better post-treatment scores on the Revised Wechsler Memory Scale than the control group.Furthermore,post-treatment P300 latency and amplitude improved significantly in the research group,surpassing the control group.EEG grading in the research group improved,and the incidence of adverse reactions was significantly lower than in the control group.CONCLUSION Patients with MCI receiving rTMS therapy demonstrated improved memory and cognitive functions and EEG grading and exhibited high safety with fewer adverse reactions.
基金supported by the National Research Foundation of Korea funded by the Korean Government(grant No.RS-2023-00208801).
文摘As artificial intelligence and big data become increasingly prevalent, resistive random-access memory (RRAM) has become one of the most promising alternatives for storing massive amounts of data. In this study, we employed high-quality crystalline TiN/Al_(2)O_(3)/BaTiO_(3)/Pt RRAM with an optimized thin Al_(2)O_(3) interlayer around 12 nm thick prepared using atomic layer deposition since the thickness of the interlayer affects the memory window size. After insertion of the Al_(2)O_(3) interlayer, the novel RRAM exhibited outstanding uniform resistive switching voltage and the ON/OFF memory window drastically increased from 10 to 103 without any discernible decline in performance. Moreover, the low-resistance state and high-resistance state operating current values decreased by almost one order and three orders of magnitude, respectively, thereby decreasing the power consumption for the RESET and SET processes by more than three and almost one order of magnitude, respectively. The device also exhibits multilevel resistive switching behavior when varying the applied voltage. Finally, we also developed a 6 6 crossbar array which demonstrated consistent and reliable resistive switching behavior with minimal variation. Hence, our approach holds great promise for producing state-of-the-art non-volatile resistive switching devices.
基金supported by the National Natural Science Foundation of China(12202294)the Sichuan Science and Technology Program(2024NSFSC1346).
文摘Shape memory alloys(SMAs)and shape memory ceramics(SMCs)exhibit high recovery ability due to the martensitic transformation,which complicates the fracture mechanism of SMAs and SMCs.The phase field method,as a powerful numerical simulation tool,can efficiently resolve the microstructural evolution,multi-field coupling effects,and fracture behavior of SMAs and SMCs.This review begins by presenting the fundamental theoretical framework of the fracture phase field method as applied to SMAs and SMCs,covering key aspects such as the phase field modeling of martensitic transformation and brittle fracture.Subsequently,it systematically examines the phase field simulations of fracture behaviors in SMAs and SMCs,with particular emphasis on how crystallographic orientation,grain size,and grain boundary properties influence the crack propagation.Additionally,the interplay between martensite transformation and fracture mechanisms is analyzed to provide deeper insights into the material responses under mechanical loading.Finally,the review explores future prospects and emerging trends in phase field simulations of SMA and SMC fracture behavior,along with potential advancements in the fracture phase field method itself,including multi-physics coupling and enhanced computational efficiency for large-scale simulations.
文摘At the beginning of the 20^(th)century,German scientist Richard Semon introduced the term'engram'to describe the neural substrate implicated in the processes of memory formation and retrieval[1].The trace of the corresponding biophysical and biochemical changes in the brain responding to an external stimulus is called an engram,and understanding the physical manifestations of memory formation and recall remains a fundamental yet unresolved question[2].
基金supported by the Aeronautical Science Foundation of China(Grant Nos.2024Z009052003,20230038052001 and 20230015052002)the Third Batch of Science and Technology Plan Projects in Changzhou City in 2023(Applied Basic Research,Grant No.CJ20230080).
文摘This paper presents the development of a thermoplastic shape memory rubber that can be programmed at human body temperature for comfortable fitting applications.We hybridized commercially available thermoplastic rubber(TPR)used in the footwear industry with un-crosslinked polycaprolactone(PCL)to create two samples,namely TP6040 and TP7030.The shape memory behavior,elasticity,and thermo-mechanical response of these rubbers were systematically investigated.The experimental results demonstrated outstanding shape memory performance,with both samples achieving shape fixity ratios(Rf)and shape recovery ratios(R_(r))exceeding 94%.TP6040 exhibited a fitting time of 80 s at body temperature(37℃),indicating a rapid response for shape fixing.The materials also showed good elasticity before and after programming,which is crucial for comfort fitting.These findings suggest that the developed shape memory thermoplastic rubber has potential applications in personalized comfort fitting products,offering advantages over traditional customization techniques in terms of efficiency and cost-effectiveness.
基金supported in part by the National Natural Science Foundation of China (62422405, 62025111,62495100, 92464302)the STI 2030-Major Projects(2021ZD0201200)+1 种基金the Shanghai Municipal Science and Technology Major Projectthe Beijing Advanced Innovation Center for Integrated Circuits
文摘Computing-in-memory(CIM)has been a promising candidate for artificial-intelligent applications thanks to the absence of data transfer between computation and storage blocks.Resistive random access memory(RRAM)based CIM has the advantage of high computing density,non-volatility as well as high energy efficiency.However,previous CIM research has predominantly focused on realizing high energy efficiency and high area efficiency for inference,while little attention has been devoted to addressing the challenges of on-chip programming speed,power consumption,and accuracy.In this paper,a fabri-cated 28 nm 576K RRAM-based CIM macro featuring optimized on-chip programming schemes is proposed to address the issues mentioned above.Different strategies of mapping weights to RRAM arrays are compared,and a novel direct-current ADC design is designed for both programming and inference stages.Utilizing the optimized hybrid programming scheme,4.67×programming speed,0.15×power saving and 4.31×compact weight distribution are realized.Besides,this macro achieves a normalized area efficiency of 2.82 TOPS/mm2 and a normalized energy efficiency of 35.6 TOPS/W.
文摘A Shape Memory Polymer Composite(SMPC)is developed by reinforcing an epoxy-based polymer with randomly oriented short glass fibers.Diverging from previous research,which primarily focused on the hot programming of short glass fiber-based SMPCs,this work explores the potential for programming below the glass transition temperature(Tg)for epoxy-based SMPCs.To mitigate the inherent brittleness of the SMPC during deformation,a linear polymer is incorporated,and a temperature between room temperature and Tg is chosen as the deformation temperature to study the shape memory properties.The findings demonstrate an enhancement in shape fixity and recovery stress,alongside a reduction in shape recovery,with the incorporation of short glass fibers.In addition to tensile properties,thermal properties such as thermal conductivity,specific heat capacity,and glass transition temperature are investigated for their dependence on fiber content.Microscopic properties,such as fiber-matrix adhesion and the dispersion of glass fibers,are examined through Scanning Electron Microscope imaging.The fiber length distribution and mean fiber lengths are also measured for different fiber fractions.
文摘设计了一套存储器辐射效应远程在线测试系统,对一款磁阻随机存取存储器(Magnetoresistive Random Access Memory,MRAM)在不同工作模式下开展了电离总剂量和瞬态电离辐射效应实验研究,获得了以下研究结果:1)电离总剂量辐照实验中,在动态读写模式下,首先出现的效应为电源电流显著增加,器件在30 krad(Si)时,出现了读数据错误;2)瞬态电离辐射辐照实验中,MRAM在静态加电模式和动态读数据模式未观测到数据或功能错误,但在动态写数据模式下出现数据写入失败的现象。初步分析认为写数据失败的原因可能是γ射线引起的PN结光电流形成电路全局光电流,造成MRAM电源波动,触发MRAM写保护有效。本文研究结果表明在总剂量与瞬态电离辐射环境下,MRAM会出现功能异常。MRAM的外围电路是其抗辐射性能的敏感薄弱环节。
基金Supported by National Natural Science Foundation of China Under Grant(12401647)Supported by Fundamental Research Program of Shanxi Province(202203021212336)+2 种基金Taiyuan Institute of Technology Scientific Research Initial Funding(2023KJ057,2024KJ007,2024LJ005)Supported by Scientific and Technologial Innovation Programs of Higher Education Institutions in Shanxi(2024L358)Youth Program of Taiyuan University(24TYQN10)。
文摘The main purpose of this paper is to investigate the singularities of solutions to the single Tricomi equation with derivative term and combined memory term.In addition,the blow-up of the solution to the weakly coupled system with memory term is also considered,where one is a power nonlinear term and the other is a derivative nonlinear term.Upper bound lifespan estimates of solution are obtained in the sub-critical by utilizing the test function method and iteration technique.The innovation of this paper focuses on the lifespan estimates of the solutions,which extends the well-known Strauss and Glassey conjectures.
基金Our laboratory is supported by grants from the Swedish Research Council(2021-01468)Cancerfonden(211602 Pj and 243516 Pj)+2 种基金Barncancerfonden(PR2023-0091)Radiumhemmets Forskningsfonder(231233)the Knut and Alice Wallenberg Foundation(KAW 2024.0097).
文摘The distinctive feature of the adaptive immune system is its ability to generate immunological memory that can provide defense against subsequent infections.In the case of antibody-mediated immune responses,this memory comes in two cellular forms:plasma cells(PCs)and memory B cells(MBCs).PCs protect against reinfection by constitutively producing antibodies.The presence of a diverse pool of MBCs,which can expand and differentiate into PCs in secondary immune responses,is thought to be particularly important for defense against new pathogen variants.Recent studies have shown that the MBC compartment is far more heterogeneous than previously anticipated.This heterogeneity,among other factors,is shaped by their developmental pathway(germinal center(GC)vs non-GC-derived MBCs),the duration and strength of antigenic stimulation,anatomical and microanatomical localization,and the timing of generation in ontogeny.Combinations of these“layers”of MBC identities can define MBCs’properties and their fate in recall responses.Here,we review the mechanisms underlying MBC differentiation,maintenance,and reactivation and explore how the layered identity of MBCs contributes to the functions of these cells.
基金supported by the National Natural Science Foundation of China,Nos.31972914,31771175(both to YH).
文摘Aerobic exercise facilitates synaptic plasticity,thereby improving cognitive functions such as learning and memory.The 5-hydroxytryptamine system has been indicated in these processes.5-Hydroxytryptamine type 3 receptors are necessary for exercise-induced hippocampal neurogenesis.Some antipsychotic drugs with 5-hydroxytryptamine type 3 receptor antagonistic properties may impede the amelioration of cognitive impairment and hippocampal plasticity induced by exercise.However,the mechanisms underlying the facilitation of synaptic plasticity by aerobic exercise have not yet been elucidated.In this study,we found that 5-hydroxytryptamine type 3 receptors played an important role in aerobic exercise-mediated improvement of hippocampal-dependent spatial and exploratory memory in mice.While 5-hydroxytryptamine type 3 receptors did not affect baseline neurogenesis in the hippocampal dentate gyrus,5-hydroxytryptamine type 3 receptors were required for aerobic exercise-induced neurogenesis and astrocyte proliferation in this region.In addition,5-hydroxytryptamine type 3 receptors were crucial for maintaining long-term potentiation in the CA1,dentate gyrus,and CA3 regions of the hippocampus.The long-term potentiation changes induced by aerobic exercise in sub-regions of the hippocampus were heterogeneous:5-hydroxytryptamine type 3 receptors were essential for aerobic exercise to enhance long-term potentiation in the CA3,but not the CA1 or dentate gyrus,regions of the hippocampus.Furthermore,aerobic exercise up-regulated 5-hydroxytryptamine type 3 receptor expression and increased brain-derived neurotrophic factor release in the hippocampus in a 5-hydroxytryptamine type 3 receptor-dependent manner.These results suggest that aerobic exercise increases hippocampal dentate gyrus neurogenesis and astrocyte proliferation via the up-regulation of 5-hydroxytryptamine type 3 receptors,leading to more brain-derived neurotrophic factor production and release from these cells,which results in long-term potentiation facilitation in the hippocampal CA3 region and help improve memory.Our findings provide insight into the mechanisms by which physical activity enhances memory and may have implications for improving memory through modulating 5-hydroxytryptamine type 3 receptor.
基金the support of the National Natural Science Foundation of China(Nos.22205207 and 22378369).
文摘With the acceleration of industrialization,the pollution problem of sulfur dioxide(SO_(2))emitted from coal-fired power plants has become increasingly severe.Although wet flue gas desulfurization(FGD)technology can remove about 95%of SO_(2),its high energy consumption and the corrosion risk of downstream equipment caused by residual SO_(2)(500–3000 ppm)still need to be addressed[1].Previous porous materials(such as MOFs)achieve selective adsorption of SO_(2) through open metal sites,M–OH sites or functional organic groups,but the problem of CO_(2) co-adsorption limits their practical application[2].In recent years,hydrogen-bonded organic frameworks(HOFs)have emerged as a research hotspot due to their reversible hydrogen-bonding networks and flexible structures[3],but their stability under extreme conditions and efficient separation performance still need to be improved[4].
基金supported by the National Natural Science Foundation of China(Nos.51603005,52403186 and 52573150)Fujian Provincial Natural Science Foundation of China(No.2024J011447)+1 种基金Natural Science Foundation of Xiamen,China(No.3502Z20227305)the Postdoctoral Fellowship Program of CPSF(No.GZC20240095)。
文摘Near-infrared(NIR)light-responsive shape memory polymers(SMPs)show great promise for biomedical applications,but conventional photothermal agents suffer from high cost,complex preparation,or poor biocompatibility,while lignin-based alternatives exhibit insufficient photothermal conversion efficiency.Herein,we developed a novel strategy to enhance photothermal performance of lignin through sequential demethylation modification and Fe^(3+)complexation for constructing NIR light responsive SMPs.Dealkaline lignin(DL)was first demethylated using iodocyclohexane to produce demethylated lignin(DDL)with increased catechol content,which was then incorporated into polycaprolactone-based polyurethane synthesis followed by Fe^(3+)complexation.Results showed that DDL-Fe^(3+)complexes have significantly enhanced photothermal conversion performance,and the resulting PU-DDL+Fe^(3+)polyurethane with 0.5 wt%DDL content demonstrated a temperature increases of 39.8℃under 0.33 W·cm-2808 nm NIR irradiation.This excellent photothermal performance enables the shape-fixed PU-DDL+Fe^(3+)polyurethane to rapidly recover to its initial shape under NIR light irradiation.Additionally,PU-DDL+Fe^(3+)polyurethane exhibits good mechanical properties and biocompatibility,demonstrating significant biomedical application potential.
基金Supported by the National Natural Science Foundation of China(Grant Nos.11961059,1210502)the University Innovation Project of Gansu Province(Grant No.2023B-062)the Gansu Province Basic Research Innovation Group Project(Grant No.23JRRA684).
文摘The goal of this paper is to investigate the long-time dynamics of solutions to a Kirchhoff type suspension bridge equation with nonlinear damping and memory term.For this problem we establish the well-posedness and existence of uniform attractor under some suitable assumptions on the nonlinear term g(u),the nonlinear damping f(u_(t))and the external force h(x,t).Specifically,the asymptotic compactness of the semigroup is verified by the energy reconstruction method.
基金supported by the Tianjin Scientific Research Start-up Foundation for Talent Introduction(2021-1-10)the 14th Five-Year Plan Peak Discipline Support Plan of Tianjin Medical University Cancer Institute and Hospital(7-2-13)+3 种基金National Natural Science Foundation of China(82171221),Beijing Bethune Charitable Foundation(YXJL-2024-0778-0030)Beijing Science and Technology Innovation Medical Development Foundation(KC2024-JF-0069)Tianjin Medical University Postgraduate Education Reform Research Program(TMUYY02)Tianjin Key Medical Discipline(Specialty)Construction(TJYXZDXK-009A).
文摘GABA_(A) receptors containingα5-subunits(GABA_(A)R-α5)cluster at both extrasynaptic and synaptic locations,interacting with the scaffold proteins radixin and gephyrin,respectively,and the re-localization of GABA_(A)R-α5 influences GABAergic transmission.Here,we found that when early spatial memory deficits occurred in aged mice at 24 h after sevoflurane anesthesia,there was a re-localization of GABA_(A)R-α5 that enhanced tonic inhibition and reduced the decay kinetics of miniature inhibitory postsynaptic currents in the hippocampal CA1 region.Mechanistically,increased phosphorylation of radixin at threonine 564(Thr564)mediates the re-localization of GABA_(A)R-α5.Acute treatment with the selective extrasynaptic GABA_(A)R-α5 antagonist S44819 restored the GABA_(A)R-α5-mediated inhibitory currents by reversing radixin phosphorylation-dependent GABA_(A)R-α5 re-localization,then improved the sevoflurane-induced spatial memory impairment in aged mice.Our results suggest that the localization of GABA_(A)R-α5 altered by sevoflurane is linked to unbalanced GABAergic transmission,which induces early memory impairment in aged mice.Modulating the GABA_(A)R-α5 localization might be a novel strategy to improve memory after sevoflurane exposure.
基金supported by National Research Foundation of Korea(NRF)funded by Ministry of Science and ICT(MSIT)(No.RS-2023-00260527,RS-2024-00407282,RS-2025-00557667)supported by Hanyang University Industry-University Cooperation Foundation(No.202400000003943)supported by Korea Planning&Evaluation Institute of Industrial Technology(KEIT)funded by South Korean Ministry of Trade,Industry and Energy(MOTIE)(No.RS-2025-25454815,RS-2025-02308064,20017382)。
文摘Oxide semiconductors(OSs),introduced by the Hosono group in the early 2000s,have evolved from display backplane materials to promising candidates for advanced memory and logic devices.The exceptionally low leakage current of OSs and compatibility with three-dimensional(3D)architectures have recently sparked renewed interest in their use in semiconductor applications.This review begins by exploring the unique material properties of OSs,which fundamentally originate from their distinct electronic band structure.Subsequently,we focus on atomic layer deposition(ALD),a core technique for growing excellent OS films,covering both basic and advanced processes compatible with 3D scaling.The basic surface reaction mechanisms—adsorption and reaction—and their roles in film growth are introduced.Furthermore,material design strategies,such as cation selection,crystallinity control,anion doping,and heterostructure engineering,are discussed.We also highlight challenges in memory applications,including contact resistance,hydrogen instability,and lack of p-type materials,and discuss the feasibility of ALD-grown OSs as potential solutions.Lastly,we provide an outlook on the role of ALD-grown OSs in memory technologies.This review bridges material fundamentals and device-level requirements,offering a comprehensive perspective on the potential of ALD-driven OSs for next-generation semiconductor memory devices.
