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
The highly dynamic nature,strong uncertainty,and coupled multiple safety constraints inherent in carrier aircraft recovery operations pose severe challenges for real-time decision-making.Addressing bolter scenarios,th...The highly dynamic nature,strong uncertainty,and coupled multiple safety constraints inherent in carrier aircraft recovery operations pose severe challenges for real-time decision-making.Addressing bolter scenarios,this study proposes an intelligent decision-making framework based on a deep long short-term memory Q-network.This framework transforms the real-time sequencing for bolter recovery problem into a partially observable Markov decision process.It employs a stacked long shortterm memory network to accurately capture the long-range temporal dependencies of bolter event chains and fuel consumption.Furthermore,it integrates a prioritized experience replay training mechanism to construct a safe and adaptive scheduling system capable of millisecond-level real-time decision-making.Experimental demonstrates that,within large-scale mass recovery scenarios,the framework achieves zero safety violations in static environments and maintains a fuel safety violation rate below 10%in dynamic scenarios,with single-step decision times at the millisecond level.The model exhibits strong generalization capability,effectively responding to unforeseen emergent situations—such as multiple bolters and fuel emergencies—without requiring retraining.This provides robust support for efficient carrier-based aircraft recovery operations.展开更多
Artificial intelligence(AI)processes data-centric applications with minimal effort.However,it poses new challenges to system design in terms of computational speed and energy efficiency.The traditional von Neumann arc...Artificial intelligence(AI)processes data-centric applications with minimal effort.However,it poses new challenges to system design in terms of computational speed and energy efficiency.The traditional von Neumann architecture cannot meet the requirements of heavily datacentric applications due to the separation of computation and storage.The emergence of computing inmemory(CIM)is significant in circumventing the von Neumann bottleneck.A commercialized memory architecture,static random-access memory(SRAM),is fast and robust,consumes less power,and is compatible with state-of-the-art technology.This study investigates the research progress of SRAM-based CIM technology in three levels:circuit,function,and application.It also outlines the problems,challenges,and prospects of SRAM-based CIM macros.展开更多
A modified four transistor （4T） self-body-bias structured SRAM/SOI memory cell is proposed. The structure is designed and its parameters are obtained by performance simulation and analysis with TSUPREM4 and MEDICI.T...A modified four transistor （4T） self-body-bias structured SRAM/SOI memory cell is proposed. The structure is designed and its parameters are obtained by performance simulation and analysis with TSUPREM4 and MEDICI.The structure saves area and its process is simplified by using the body resistor with buried p^＋ channel beneath the nMOS gate instead of the pMOS of 6T CMOS SRAM. Furthermore, this structure can operate safely with a 0.5V supply voltage, which may be prevalent in the near future. Finally, compared to conventional 6T CMOS SRAM,this structure＇s transient responses are normal and its power dissipation is 10 times smaller.展开更多
基于系统级封装(System in a Package, SiP)技术的SRAM型FPGA微系统广泛应用于航天领域。由于微系统复杂的封装结构,限制了大多数传统失效分析设备与分析方式的应用。针对微系统器件的故障诊断困难、测试流程复杂等可靠性问题,开展了常...基于系统级封装(System in a Package, SiP)技术的SRAM型FPGA微系统广泛应用于航天领域。由于微系统复杂的封装结构,限制了大多数传统失效分析设备与分析方式的应用。针对微系统器件的故障诊断困难、测试流程复杂等可靠性问题,开展了常见故障分析研究。对SRAM配置固有缺陷和FPGA内部配置刷新电路异常等典型故障的产生机理进行了深入分析和总结。结合理论分析和问题现象,提出了配置位回读校验测试及比对、辅助电源VCC, AUX电流参数一致性控制等测试筛选方法,有效提升了测试覆盖性。利用相应测试手段和数据分析方法,可精准定位失效机理与失效部位,对后续宇航用SRAM型FPGA微系统应用及筛选有重要意义。展开更多
In recent years,carbon nanotube field effect transistor(CNTFET)has become an attractive alternative to silicon for designing high-performance,highly stable,and low-power static random access memory(SRAM).SRAM serves a...In recent years,carbon nanotube field effect transistor(CNTFET)has become an attractive alternative to silicon for designing high-performance,highly stable,and low-power static random access memory(SRAM).SRAM serves as a cache memory in computers and many portable devices.Carbon nanotubes(CNTs),because of their exceptional transport capabilities,outstanding thermal conductivities,and impressive current handling capacities,have demonstrated great potential as an alternative device to the standard complementary metal-oxide-semiconductor(CMOS).The SRAM cell design using CNTFET is being compared to SRAM cell designs built using traditional CMOS technology.This paper presents the comprehensive analysis of CMOS&CNTFET based 8T SRAM cell design.Because of the nanoscale size,ballistic transport,and higher carrier mobility of the semiconducting nanotubes in CNTFET,it is integrated into the 8T SRAM cell.The approach incorporates several nonidealities,including the presence of quantum confinement consequences in the peripheral and transverse prescriptions,acoustic and transparent photon diffraction in the region surrounding the channel,as well as the screening effects by parallel CNTs in CNTFETs with multiple CNTs.By incorporating Stanford University CNTFET model in CADENCE(virtuoso)32 nm simulation,we have found that CNTFET SRAM cell is 4 times faster in terms of write/read delay and the write/read power delay product(PDP)value is almost 5 times lower compared to CMOS based SRAM.We have also analyzed the effect of temperature&different tube positions of CNTs on the performance evaluation of the 8T SRAM cell.展开更多
This paper explores the impact of back-gate bias (V_(soi)) and supply voltage (V_(DD)) on the single-event upset (SEU) cross section of 0.18μm configurable silicon-on-insulator static random-access memory (SRAM) unde...This paper explores the impact of back-gate bias (V_(soi)) and supply voltage (V_(DD)) on the single-event upset (SEU) cross section of 0.18μm configurable silicon-on-insulator static random-access memory (SRAM) under high linear energy transfer heavyion experimentation.The experimental findings demonstrate that applying a negative back-gate bias to NMOS and a positive back-gate bias to PMOS enhances the SEU resistance of SRAM.Specifically,as the back-gate bias for N-type transistors(V_(nsoi)) decreases from 0 to-10 V,the SEU cross section decreases by 93.23%,whereas an increase in the back-gate bias for P-type transistors (V_(psoi)) from 0 to 10 V correlates with an 83.7%reduction in SEU cross section.Furthermore,a significant increase in the SEU cross section was observed with increase in supply voltage,as evidenced by a 159%surge at V_(DD)=1.98 V compared with the nominal voltage of 1.8 V.To explore the physical mechanisms underlying these experimental data,we analyzed the dependence of the critical charge of the circuit and the collected charge on the bias voltage by simulating SEUs using technology computer-aided design.展开更多
Photonic platforms are gradually emerging as a promising option to encounter the ever-growing demand for artificial intelligence,among which photonic time-delay reservoir computing(TDRC)is widely anticipated.While suc...Photonic platforms are gradually emerging as a promising option to encounter the ever-growing demand for artificial intelligence,among which photonic time-delay reservoir computing(TDRC)is widely anticipated.While such a computing paradigm can only employ a single photonic device as the nonlinear node for data processing,the performance highly relies on the fading memory provided by the delay feedback loop(FL),which sets a restriction on the extensibility of physical implementation,especially for highly integrated chips.Here,we present a simplified photonic scheme for more flexible parameter configurations leveraging the designed quasi-convolution coding(QC),which completely gets rid of the dependence on FL.Unlike delay-based TDRC,encoded data in QC-based RC(QRC)enables temporal feature extraction,facilitating augmented memory capabilities.Thus,our proposed QRC is enabled to deal with time-related tasks or sequential data without the implementation of FL.Furthermore,we can implement this hardware with a low-power,easily integrable vertical-cavity surface-emitting laser for high-performance parallel processing.We illustrate the concept validation through simulation and experimental comparison of QRC and TDRC,wherein the simpler-structured QRC outperforms across various benchmark tasks.Our results may underscore an auspicious solution for the hardware implementation of deep neural networks.展开更多
Hippocampal neuronal loss causes cognitive dysfunction in Alzheimer’s disease.Adult hippocampal neurogenesis is reduced in patients with Alzheimer’s disease.Exercise stimulates adult hippocampal neurogenesis in rode...Hippocampal neuronal loss causes cognitive dysfunction in Alzheimer’s disease.Adult hippocampal neurogenesis is reduced in patients with Alzheimer’s disease.Exercise stimulates adult hippocampal neurogenesis in rodents and improves memory and slows cognitive decline in patients with Alzheimer’s disease.However,the molecular pathways for exercise-induced adult hippocampal neurogenesis and improved cognition in Alzheimer’s disease are poorly understood.Recently,regulator of G protein signaling 6(RGS6)was identified as the mediator of voluntary running-induced adult hippocampal neurogenesis in mice.Here,we generated novel RGS6fl/fl;APP_(SWE) mice and used retroviral approaches to examine the impact of RGS6 deletion from dentate gyrus neuronal progenitor cells on voluntary running-induced adult hippocampal neurogenesis and cognition in an amyloid-based Alzheimer’s disease mouse model.We found that voluntary running in APP_(SWE) mice restored their hippocampal cognitive impairments to that of control mice.This cognitive rescue was abolished by RGS6 deletion in dentate gyrus neuronal progenitor cells,which also abolished running-mediated increases in adult hippocampal neurogenesis.Adult hippocampal neurogenesis was reduced in sedentary APP_(SWE) mice versus control mice,with basal adult hippocampal neurogenesis reduced by RGS6 deletion in dentate gyrus neural precursor cells.RGS6 was expressed in neurons within the dentate gyrus of patients with Alzheimer’s disease with significant loss of these RGS6-expressing neurons.Thus,RGS6 mediated voluntary running-induced rescue of impaired cognition and adult hippocampal neurogenesis in APP_(SWE) mice,identifying RGS6 in dentate gyrus neural precursor cells as a possible therapeutic target in Alzheimer’s disease.展开更多
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 the National Natural Science Foundation of China(Grant No.62403486)。
文摘The highly dynamic nature,strong uncertainty,and coupled multiple safety constraints inherent in carrier aircraft recovery operations pose severe challenges for real-time decision-making.Addressing bolter scenarios,this study proposes an intelligent decision-making framework based on a deep long short-term memory Q-network.This framework transforms the real-time sequencing for bolter recovery problem into a partially observable Markov decision process.It employs a stacked long shortterm memory network to accurately capture the long-range temporal dependencies of bolter event chains and fuel consumption.Furthermore,it integrates a prioritized experience replay training mechanism to construct a safe and adaptive scheduling system capable of millisecond-level real-time decision-making.Experimental demonstrates that,within large-scale mass recovery scenarios,the framework achieves zero safety violations in static environments and maintains a fuel safety violation rate below 10%in dynamic scenarios,with single-step decision times at the millisecond level.The model exhibits strong generalization capability,effectively responding to unforeseen emergent situations—such as multiple bolters and fuel emergencies—without requiring retraining.This provides robust support for efficient carrier-based aircraft recovery operations.
基金the National Key Research and Development Program of China(2018YFB2202602)The State Key Program of the National Natural Science Foundation of China(NO.61934005)+1 种基金The National Natural Science Foundation of China(NO.62074001)Joint Funds of the National Natural Science Foundation of China under Grant U19A2074.
文摘Artificial intelligence(AI)processes data-centric applications with minimal effort.However,it poses new challenges to system design in terms of computational speed and energy efficiency.The traditional von Neumann architecture cannot meet the requirements of heavily datacentric applications due to the separation of computation and storage.The emergence of computing inmemory(CIM)is significant in circumventing the von Neumann bottleneck.A commercialized memory architecture,static random-access memory(SRAM),is fast and robust,consumes less power,and is compatible with state-of-the-art technology.This study investigates the research progress of SRAM-based CIM technology in three levels:circuit,function,and application.It also outlines the problems,challenges,and prospects of SRAM-based CIM macros.
文摘A modified four transistor （4T） self-body-bias structured SRAM/SOI memory cell is proposed. The structure is designed and its parameters are obtained by performance simulation and analysis with TSUPREM4 and MEDICI.The structure saves area and its process is simplified by using the body resistor with buried p^＋ channel beneath the nMOS gate instead of the pMOS of 6T CMOS SRAM. Furthermore, this structure can operate safely with a 0.5V supply voltage, which may be prevalent in the near future. Finally, compared to conventional 6T CMOS SRAM,this structure＇s transient responses are normal and its power dissipation is 10 times smaller.
文摘基于系统级封装(System in a Package, SiP)技术的SRAM型FPGA微系统广泛应用于航天领域。由于微系统复杂的封装结构,限制了大多数传统失效分析设备与分析方式的应用。针对微系统器件的故障诊断困难、测试流程复杂等可靠性问题,开展了常见故障分析研究。对SRAM配置固有缺陷和FPGA内部配置刷新电路异常等典型故障的产生机理进行了深入分析和总结。结合理论分析和问题现象,提出了配置位回读校验测试及比对、辅助电源VCC, AUX电流参数一致性控制等测试筛选方法,有效提升了测试覆盖性。利用相应测试手段和数据分析方法,可精准定位失效机理与失效部位,对后续宇航用SRAM型FPGA微系统应用及筛选有重要意义。
文摘In recent years,carbon nanotube field effect transistor(CNTFET)has become an attractive alternative to silicon for designing high-performance,highly stable,and low-power static random access memory(SRAM).SRAM serves as a cache memory in computers and many portable devices.Carbon nanotubes(CNTs),because of their exceptional transport capabilities,outstanding thermal conductivities,and impressive current handling capacities,have demonstrated great potential as an alternative device to the standard complementary metal-oxide-semiconductor(CMOS).The SRAM cell design using CNTFET is being compared to SRAM cell designs built using traditional CMOS technology.This paper presents the comprehensive analysis of CMOS&CNTFET based 8T SRAM cell design.Because of the nanoscale size,ballistic transport,and higher carrier mobility of the semiconducting nanotubes in CNTFET,it is integrated into the 8T SRAM cell.The approach incorporates several nonidealities,including the presence of quantum confinement consequences in the peripheral and transverse prescriptions,acoustic and transparent photon diffraction in the region surrounding the channel,as well as the screening effects by parallel CNTs in CNTFETs with multiple CNTs.By incorporating Stanford University CNTFET model in CADENCE(virtuoso)32 nm simulation,we have found that CNTFET SRAM cell is 4 times faster in terms of write/read delay and the write/read power delay product(PDP)value is almost 5 times lower compared to CMOS based SRAM.We have also analyzed the effect of temperature&different tube positions of CNTs on the performance evaluation of the 8T SRAM cell.
基金supported by the National Key Laboratory of Materials Behavior and Evaluation Technology in Space Environment(No.6142910220208)National Natural Science Foundation of China(Nos.12105341 and 12035019)the opening fund of Key Laboratory of Silicon Device and Technology,Chinese Academy of Sciences(No.KLSDTJJ2022-3).
文摘This paper explores the impact of back-gate bias (V_(soi)) and supply voltage (V_(DD)) on the single-event upset (SEU) cross section of 0.18μm configurable silicon-on-insulator static random-access memory (SRAM) under high linear energy transfer heavyion experimentation.The experimental findings demonstrate that applying a negative back-gate bias to NMOS and a positive back-gate bias to PMOS enhances the SEU resistance of SRAM.Specifically,as the back-gate bias for N-type transistors(V_(nsoi)) decreases from 0 to-10 V,the SEU cross section decreases by 93.23%,whereas an increase in the back-gate bias for P-type transistors (V_(psoi)) from 0 to 10 V correlates with an 83.7%reduction in SEU cross section.Furthermore,a significant increase in the SEU cross section was observed with increase in supply voltage,as evidenced by a 159%surge at V_(DD)=1.98 V compared with the nominal voltage of 1.8 V.To explore the physical mechanisms underlying these experimental data,we analyzed the dependence of the critical charge of the circuit and the collected charge on the bias voltage by simulating SEUs using technology computer-aided design.
基金National Natural Science Foundation of China(62171305,62405206,62004135,62001317,62111530301)Natural Science Foundation of Jiangsu Province(BK20240778,BK20241917)+3 种基金State Key Laboratory of Advanced Optical Communication Systems and Networks,China(2023GZKF08)China Postdoctoral Science Foundation(2024M752314)Postdoctoral Fellowship Program of CPSF(GZC20231883)Innovative and Entrepreneurial Talent Program of Jiangsu Province(JSSCRC2021527).
文摘Photonic platforms are gradually emerging as a promising option to encounter the ever-growing demand for artificial intelligence,among which photonic time-delay reservoir computing(TDRC)is widely anticipated.While such a computing paradigm can only employ a single photonic device as the nonlinear node for data processing,the performance highly relies on the fading memory provided by the delay feedback loop(FL),which sets a restriction on the extensibility of physical implementation,especially for highly integrated chips.Here,we present a simplified photonic scheme for more flexible parameter configurations leveraging the designed quasi-convolution coding(QC),which completely gets rid of the dependence on FL.Unlike delay-based TDRC,encoded data in QC-based RC(QRC)enables temporal feature extraction,facilitating augmented memory capabilities.Thus,our proposed QRC is enabled to deal with time-related tasks or sequential data without the implementation of FL.Furthermore,we can implement this hardware with a low-power,easily integrable vertical-cavity surface-emitting laser for high-performance parallel processing.We illustrate the concept validation through simulation and experimental comparison of QRC and TDRC,wherein the simpler-structured QRC outperforms across various benchmark tasks.Our results may underscore an auspicious solution for the hardware implementation of deep neural networks.
基金supported by the National Institutes of Health,Nos.AA025919,AA025919-03S1,and AA025919-05S1(all to RAF).
文摘Hippocampal neuronal loss causes cognitive dysfunction in Alzheimer’s disease.Adult hippocampal neurogenesis is reduced in patients with Alzheimer’s disease.Exercise stimulates adult hippocampal neurogenesis in rodents and improves memory and slows cognitive decline in patients with Alzheimer’s disease.However,the molecular pathways for exercise-induced adult hippocampal neurogenesis and improved cognition in Alzheimer’s disease are poorly understood.Recently,regulator of G protein signaling 6(RGS6)was identified as the mediator of voluntary running-induced adult hippocampal neurogenesis in mice.Here,we generated novel RGS6fl/fl;APP_(SWE) mice and used retroviral approaches to examine the impact of RGS6 deletion from dentate gyrus neuronal progenitor cells on voluntary running-induced adult hippocampal neurogenesis and cognition in an amyloid-based Alzheimer’s disease mouse model.We found that voluntary running in APP_(SWE) mice restored their hippocampal cognitive impairments to that of control mice.This cognitive rescue was abolished by RGS6 deletion in dentate gyrus neuronal progenitor cells,which also abolished running-mediated increases in adult hippocampal neurogenesis.Adult hippocampal neurogenesis was reduced in sedentary APP_(SWE) mice versus control mice,with basal adult hippocampal neurogenesis reduced by RGS6 deletion in dentate gyrus neural precursor cells.RGS6 was expressed in neurons within the dentate gyrus of patients with Alzheimer’s disease with significant loss of these RGS6-expressing neurons.Thus,RGS6 mediated voluntary running-induced rescue of impaired cognition and adult hippocampal neurogenesis in APP_(SWE) mice,identifying RGS6 in dentate gyrus neural precursor cells as a possible therapeutic target in Alzheimer’s disease.
