With the atomically sharp interface and stable switching channel, van der Waals(vdW) heterostructure memristors have attracted extensive interests for the application of high-density memory and neuromorphic computing....With the atomically sharp interface and stable switching channel, van der Waals(vdW) heterostructure memristors have attracted extensive interests for the application of high-density memory and neuromorphic computing. Here, we demonstrate a new type of vdW heterostructure memristor device by sandwiching a single-crystalline h-BN layer between two thin graphites. In such a device, a stable bipolar resistive switching(RS) behavior has been observed for the first time. We also characterize their switching performance, and observe an on/off ratio of >10^(3) and a minimum RESET voltage variation coefficient of3.81%. Our work underscores the potential of 2D materials and vdW heterostructures for emerging memory and neuromorphic applications.展开更多
Neuromorphic intelligent hardware technologies have undergone rapid advancement during the past decade,with the goal of building intelligent devices and systems capable of overcoming challenges associated with convent...Neuromorphic intelligent hardware technologies have undergone rapid advancement during the past decade,with the goal of building intelligent devices and systems capable of overcoming challenges associated with conventional hardware.Realization of neuromorphic intelligent hardware depends on major advances in materials science,condensed matter physics,device physics and engineering.As a revolutionary discovery,two-dimensional(2D)materials with atomically-thin thickness and exceptionally high tunability introduce a new physical paradigm and show great promise in the development of intelligent devices.Here,we give prominence to three categories of tunable properties(i.e.,charge carrier,band structure,lattice structure)that are inherent for 2D materials and review their superiorities in constructing intelligent devices particularly in electronics and optoelectronics.Furthermore,we provide insight into how the unique physical mechanisms emerging in 2D materials offer a fertile ground for the design of diverse intelligence devices.展开更多
Room-temperature sodium-sulfur(RT Na-S)batteries are a promising next-generation energy storage device due to their low cost,high energy density(1274 Wh kg^(-1)),and environmental friendliness.However,RT Na-S batterie...Room-temperature sodium-sulfur(RT Na-S)batteries are a promising next-generation energy storage device due to their low cost,high energy density(1274 Wh kg^(-1)),and environmental friendliness.However,RT Na-S batteries face a series of vital challenges from sulfur cathode and sodium anode:(i)sluggish reaction kinetics of S and Na_(2)S/Na_(2)S_(2);(ii)severe shuttle effect from the dissolved intermediate sodium polysulfides(NaPSs);(iii)huge volume expansion induced by the change from S to Na_(2)S;(iv)continuous growth of sodium metal dendrites,leading to short-circuiting of the battery;(v)huge volume expansion/contraction of sodium anode upon sodium plating/stripping,causing uncontrollable solid-state electrolyte interphase growth and“dead sodium”formation.Various strategies have been proposed to address these issues,including physical/chemical adsorption of NaPSs,catalysts to facilitate the rapid conversion of NaPSs,high-conductive materials to promote ion/electron transfer,good sodiophilic Na anode hetero-interface homogenized Na ions flux and three-dimensional porous anode host to buffer the volume expansion of sodium.Heterostructure materials can combine these merits into one material to realize multifunctionality.Herein,the recent development of heterostructure as the host for sulfur cathode and Na anode has been reviewed.First of all,the electrochemical mechanisms of sulfur cathode/sodium anode and principles of heterostructures reinforced Na-S batteries are described.Then,the application of heterostructures in Na-S batteries is comprehensively examined.Finally,the current primary avenues of employing heterostructures in Na-S batteries are summarized.Opinions and prospects are put forward regarding the existing problems in current research,aiming to inspire the design of advanced and improved next-generation Na-S batteries.展开更多
In this study,the effects of soil spatial variability in braced excavations are investigated by focusing on three structural responses:wall bending moments,wall shear forces,and strut forces.The soil spatial variabili...In this study,the effects of soil spatial variability in braced excavations are investigated by focusing on three structural responses:wall bending moments,wall shear forces,and strut forces.The soil spatial variability is modeled using random field theory,and the generated soil parameters are mapped onto a finite element model.A procedure for automating the Monte Carlo simulation,which is used for probabilistic analysis,is described.A case study demonstrates that the soil spatial variability has a considerable effect on the excavation-induced structural responses.Furthermore,a reliability analysis is performed to estimate the failure probability for three structural failure modes.The results demonstrate the importance of considering soil spatial variability in the structural assessment of braced excavati ons.展开更多
Prostate homeostasis and regeneration rely on the proper function of adult stem/progenitor cells(Ousset et al., 2012), which have also been considered as potential cells of origin for prostate cancer(Visvader, 2011) g...Prostate homeostasis and regeneration rely on the proper function of adult stem/progenitor cells(Ousset et al., 2012), which have also been considered as potential cells of origin for prostate cancer(Visvader, 2011) given their key positions in the lineage hierarchy and self-renewal capability. Accumulating evidence reveals the existence of multipotent progenitor cells in both basal and luminal cells.展开更多
基金supported by Laboratory of Solid State Microstructures,Nanjing University(M34049)the Jiangsu Postdoctoral Research Funding Program under Grant No.2021K451C。
文摘With the atomically sharp interface and stable switching channel, van der Waals(vdW) heterostructure memristors have attracted extensive interests for the application of high-density memory and neuromorphic computing. Here, we demonstrate a new type of vdW heterostructure memristor device by sandwiching a single-crystalline h-BN layer between two thin graphites. In such a device, a stable bipolar resistive switching(RS) behavior has been observed for the first time. We also characterize their switching performance, and observe an on/off ratio of >10^(3) and a minimum RESET voltage variation coefficient of3.81%. Our work underscores the potential of 2D materials and vdW heterostructures for emerging memory and neuromorphic applications.
基金supported by the National Natural Science Foundation of China(Grant Nos.62122036,62034004,61921005,61974176,6220411012074176)+4 种基金the Natural Science Foundation of Jiangsu Province(Grant No.BK20220775)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB44000000)the National Key R&D Program of China(Grant Nos.2019YFB2205400,and 2019YFB2205402)the Fundamental Research Funds for the Central Universities(Grant No.020414380179)the support from the AIQ foundation。
文摘Neuromorphic intelligent hardware technologies have undergone rapid advancement during the past decade,with the goal of building intelligent devices and systems capable of overcoming challenges associated with conventional hardware.Realization of neuromorphic intelligent hardware depends on major advances in materials science,condensed matter physics,device physics and engineering.As a revolutionary discovery,two-dimensional(2D)materials with atomically-thin thickness and exceptionally high tunability introduce a new physical paradigm and show great promise in the development of intelligent devices.Here,we give prominence to three categories of tunable properties(i.e.,charge carrier,band structure,lattice structure)that are inherent for 2D materials and review their superiorities in constructing intelligent devices particularly in electronics and optoelectronics.Furthermore,we provide insight into how the unique physical mechanisms emerging in 2D materials offer a fertile ground for the design of diverse intelligence devices.
基金MOE SUTD Kickstarter initiative,Grant/Award Number:SKI2021_02_16111 Project,Grant/Award Number:D20015National Natural Science Foundation of China,Grant/Award Number:22109183。
文摘Room-temperature sodium-sulfur(RT Na-S)batteries are a promising next-generation energy storage device due to their low cost,high energy density(1274 Wh kg^(-1)),and environmental friendliness.However,RT Na-S batteries face a series of vital challenges from sulfur cathode and sodium anode:(i)sluggish reaction kinetics of S and Na_(2)S/Na_(2)S_(2);(ii)severe shuttle effect from the dissolved intermediate sodium polysulfides(NaPSs);(iii)huge volume expansion induced by the change from S to Na_(2)S;(iv)continuous growth of sodium metal dendrites,leading to short-circuiting of the battery;(v)huge volume expansion/contraction of sodium anode upon sodium plating/stripping,causing uncontrollable solid-state electrolyte interphase growth and“dead sodium”formation.Various strategies have been proposed to address these issues,including physical/chemical adsorption of NaPSs,catalysts to facilitate the rapid conversion of NaPSs,high-conductive materials to promote ion/electron transfer,good sodiophilic Na anode hetero-interface homogenized Na ions flux and three-dimensional porous anode host to buffer the volume expansion of sodium.Heterostructure materials can combine these merits into one material to realize multifunctionality.Herein,the recent development of heterostructure as the host for sulfur cathode and Na anode has been reviewed.First of all,the electrochemical mechanisms of sulfur cathode/sodium anode and principles of heterostructures reinforced Na-S batteries are described.Then,the application of heterostructures in Na-S batteries is comprehensively examined.Finally,the current primary avenues of employing heterostructures in Na-S batteries are summarized.Opinions and prospects are put forward regarding the existing problems in current research,aiming to inspire the design of advanced and improved next-generation Na-S batteries.
基金The second author would like to thank the support received from the National Natural Science Foundation of China through Grant No.51808405.
文摘In this study,the effects of soil spatial variability in braced excavations are investigated by focusing on three structural responses:wall bending moments,wall shear forces,and strut forces.The soil spatial variability is modeled using random field theory,and the generated soil parameters are mapped onto a finite element model.A procedure for automating the Monte Carlo simulation,which is used for probabilistic analysis,is described.A case study demonstrates that the soil spatial variability has a considerable effect on the excavation-induced structural responses.Furthermore,a reliability analysis is performed to estimate the failure probability for three structural failure modes.The results demonstrate the importance of considering soil spatial variability in the structural assessment of braced excavati ons.
基金supported by the grant JCYJ20200109141229255 from Science, Technology and Innovation Commission of Shenzhen Municipalitysupported by grants R01CA171189 and R01CA193455 from the National Cancer Institute, National Institutes of Healthsupported in part by the Emory Integrated Genomics Core, Integrated Cellular Imaging Core Facility, Winship Research Pathology Core, and Transgenic Mouse and Gene Targeting Core of Emory University Winship Cancer Institute and NIH/NCI under award number P30CA138292。
文摘Prostate homeostasis and regeneration rely on the proper function of adult stem/progenitor cells(Ousset et al., 2012), which have also been considered as potential cells of origin for prostate cancer(Visvader, 2011) given their key positions in the lineage hierarchy and self-renewal capability. Accumulating evidence reveals the existence of multipotent progenitor cells in both basal and luminal cells.
