查看更多>>摘要：Metallic alloys with high strength and large ductility are required for extreme structural applications.However,the achievement of ultrahigh strength often results in a substantially decreased ductility.Here,we report a strat-egy to achieve the strength-ductility synergy by tailoring the alloy composition to control the local stacking fault energy(SFE)of the face-centered-cubic(fcc)matrix in an L1 2-strengthened superlattice alloy.As a proof of con-cept,based on the thermodynamic calculations,we developed a non-equiatomic CoCrNi2(Al0.2Nb0 2)alloy using phase separation to create a near-equiatomic low SFE disordered CoCrNi medium-entropy alloy matrix with in situ formed high-content coherent Ni3(Al,Nb)-type ordered nanoprecipitates(～12 nm).The alloy achieves a high tensile strength up to 1.6 GPa and a uniform ductility of 33％.The low SFE of the fcc matrix promotes the formation of nanotwins and parallel microbands during plastic deformation which could remarkably enhance the strain hardening capacity.This work provides a strategy for developing ultrahigh-strength alloys with large uniform ductility.
查看更多>>摘要：Artificial vision is crucial for most artificial intelligence applications.Conventional artificial visual systems have been facing challenges in terms of real-time information processing due to the physical separation of sensors,memories,and processors,which results in the production of a large amount of redundant data as well as the data conversion and transfer between these three components consuming most of the time and energy.Emergent optoelectronic memristors with the ability to realize integrated sensing-computing-memory(ISCM)are key can-didates for solving such challenges and therefore attract increasing attention.At present,the memristive ISCM devices can only perform primary-level computing with external light signals due to the fact that only monotonic increase of memconductance upon light irradiation is achieved in most of these devices.Here,we propose an all-optically controlled memristive ISCM device based on a simple structure of Au/ZnO/Pt with the ZnO thin film sputtered at pure Ar atmosphere.This device can perform advanced computing tasks such as nonvolatile neuromorphic computing and complete Boolean logic functions only by light irradiation,owing to its ability to reversibly tune the memconductance with light.Moreover,the device shows excellent operation stability ascribed to a purely electronic memconductance tuning mechanism.Hence,this study is an important step towards the next generation of artificial visual systems.
查看更多>>摘要：Lithium-ion battery(LIB)is the key technology for climate change mitigation.The sustainability of LIB supply chain has caused widespread concern since the material utilization efficiency of LIB supply chain has not been well investigated.This study aims to fill this research gap by conducting a dynamic material flow analysis of lithium in China from 2015 to 2021.Results indicate that within the temporal boundary,lithium flow and in-use stock grew significantly in China due to the rapid development of the EV market,with lithium flow in domestic production of basic chemicals increasing by 614％to 100 kt,end-use consumption increasing by 160％to 35 kt,and in-use stock increasing by 62％to 195 kt.China has been a net importer of lithium,of which cumulative imports and exports were 343 kt and 169 kt,respectively.In addition,103 kt of lithium was converted to inventories or was lost during the processing from 2015 to 2021.By optimizing inventory and processing,developing substitutes for lithium for non-battery applications,and improving lithium recycling,China's net import dependency of lithium could be reduced from 27％-86％to 0％-16％.Our study demonstrates that it is urgent to improve material utilization efficiency so that the lithium resource supply can be secured.
查看更多>>摘要：Theranostic agents that can be sensitively and specifically activated by the tumor microenvironment(TME)have recently attracted considerable attention.In this study,TME-activatable 3,3',5,5'-tetramethylbenzidine(TMB)-copper peroxide(CuO2)@poly(lactic-co-gly colic acid)(PLGA)@red blood cell membrane(RBCM)(TCPR)nanoparticles(NPs)for second near-infrared photoacoustic imaging-guided tumor-specific photothermal therapy were developed by co-loading CuO2 NPs and TMB into PLGA camouflaged by RBCMs.As an efficient H2O2 sup-plier,once exposed to a proton-rich TME,CuO2 NPs can generate H2O2 and Cu2+,which are further reduced to Cu+by endogenous glutathione.Subsequently,the Cu+-mediated Fenton-like reaction produces cytotoxic-OH to kill the cancer cells and induce TMB-mediated photoacoustic and photothermal effects.Combined with the RBCM modification-prolonged blood circulation,TCPR NPs display excellent specificity and efficiency in suppressing tumor growth,paving the way for more accurate,safe,and efficient cancer theranostics.
查看更多>>摘要：Chronic cerebral hypoperfusion can cause progressive demyelination as well as ischemic vascular dementia,how-ever no effective treatments are available.Here,based on magnetic resonance imaging studies of patients with white matter damage,we found that this damage is associated with disorganized cortical structure.In a mouse model,optogenetic activation of glutamatergic neurons in the somatosensory cortex significantly promoted oligo-dendrocyte progenitor cell(OPC)proliferation,remyelination in the corpus callosum,and recovery of cognitive ability after cerebral hypoperfusion.The therapeutic effect of such stimulation was restricted to the upper layers of the cortex,but also spanned a wide time window after ischemia.Mechanistically,enhancement of glutamater-gic neuron-OPC functional synaptic connections is required to achieve the protection effect of activating cortical glutamatergic neurons.Additionally,skin stroking,an easier method to translate into clinical practice,activated the somatosensory cortex,thereby promoting OPC proliferation,remyelination and cognitive recovery following cerebral hypoperfusion.In summary,we demonstrated that activating glutamatergic neurons in the somatosen-sory cortex promotes the proliferation of OPCs and remyelination to recover cognitive function after chronic cerebral hypoperfusion.It should be noted that this activation may provide new approaches for treating ischemic vascular dementia via the precise regulation of glutamatergic neuron-OPC circuits.
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