Micro silicon(mSi)is a promising anode candidate for all-solid-state batteries due to its high specific capacity,low side reactions,and high tap density.However,silicon suffers from its poor electronic and ionic condu...Micro silicon(mSi)is a promising anode candidate for all-solid-state batteries due to its high specific capacity,low side reactions,and high tap density.However,silicon suffers from its poor electronic and ionic conductivity,which is particularly severe on a micro scale and in solid-state systems,leading to increased polarization and inferior electrochemical performance.Doping can broaden the transmission pathways and reduce the diffusion energy barrier for electrons and lithium ions.However,achieving effective,uniform doping in mSi is challenging due to its longer diffusion paths and higher energy barriers.Therefore,current doping research is primarily limited to nanosilicon.In this study,we successfully used a Joule-heating activated staged thermal treatment to achieve full-depth doping of germanium(Ge)in the mSi substrate.The Joule-heating process activated the mSi substrate,resulting in abundant vacancy defects that reduced the diffusion barrier of Ge into the silicon lattice and facilitated full-depth Ge doping.Surprisingly,the resulting Si-Ge anode exhibited significantly enhanced electrical conductivity(70 times).Meanwhile,the improved Li-ion conductivity in mSi and the reduced Young’s modulus enhance the electrode reaction kinetics and integrity after cycling.Ge-doped silicon anodes demonstrate excellent electrochemical performance when applied in sulfide solid-state half-cells and full-cells.This work provides substantial insights into the rational structural design of mSi alloyed anode materials,paving the way for the development of high-performance solid-state Li-ion batteries.展开更多
Extreme cold weather seriously harms human thermoregulatory system,necessitating high-performance insulating garments to maintain body temperature.However,as the core insulating layer,advanced fibrous materials always...Extreme cold weather seriously harms human thermoregulatory system,necessitating high-performance insulating garments to maintain body temperature.However,as the core insulating layer,advanced fibrous materials always struggle to balance mechanical properties and thermal insulation,resulting in their inability to meet the demands for both washing resistance and personal protection.Herein,inspired by the natural spring-like structures of cucumber tendrils,a superelastic and washable micro/nanofibrous sponge(MNFS)based on biomimetic helical fibers is directly prepared utilizing multiple-jet electrospinning technology for high-performance thermal insulation.By regulating the conductivity of polyvinylidene fluoride solution,multiple-jet ejection and multiple-stage whipping of jets are achieved,and further control of phase separation rates enables the rapid solidification of jets to form spring-like helical fibers,which are directly entangled to assemble MNFS.The resulting MNFS exhibits superelasticity that can withstand large tensile strain(200%),1000 cyclic tensile or compression deformations,and retain good resilience even in liquid nitrogen(-196℃).Furthermore,the MNFS shows efficient thermal insulation with low thermal conductivity(24.85 mW m^(-1)K^(-1)),close to the value of dry air,and remains structural stability even after cyclic washing.This work offers new possibilities for advanced fibrous sponges in transportation,environmental,and energy applications.展开更多
Strategically coupling nanoparticle hybrids and internal thermosensitive molecular switches establishes an innovative paradigm for constructing micro/nanoscale-reconfigurable robots,facilitating energyefficient CO_(2)...Strategically coupling nanoparticle hybrids and internal thermosensitive molecular switches establishes an innovative paradigm for constructing micro/nanoscale-reconfigurable robots,facilitating energyefficient CO_(2) management in life-support systems of confined space.Here,a micro/nano-reconfigurable robot is constructed from the CO_(2) molecular hunters,temperature-sensitive molecular switch,solar photothermal conversion,and magnetically-driven function engines.The molecular hunters within the molecular extension state can capture 6.19 mmol g^(−1) of CO_(2) to form carbamic acid and ammonium bicarbonate.Interestingly,the molecular switch of the robot activates a molecular curling state that facilitates CO_(2) release through nano-reconfiguration,which is mediated by the temperature-sensitive curling of Pluronic F127 molecular chains during the photothermal desorption.Nano-reconfiguration of robot alters the amino microenvironment,including increasing surface electrostatic potential of the amino group and decreasing overall lowest unoccupied molecular orbital energy level.This weakened the nucleophilic attack ability of the amino group toward the adsorption product derivatives,thereby inhibiting the side reactions that generate hard-to-decompose urea structures,achieving the lowest regeneration temperature of 55℃ reported to date.The engine of the robot possesses non-contact magnetically-driven micro-reconfiguration capability to achieve efficient photothermal regeneration while avoiding local overheating.Notably,the robot successfully prolonged the survival time of mice in the sealed container by up to 54.61%,effectively addressing the issue of carbon suffocation in confined spaces.This work significantly enhances life-support systems for deep-space exploration,while stimulating innovations in sustainable carbon management technologies for terrestrial extreme environments.展开更多
Mine filling materials urgently need to improve mechanical properties and achieve low-carbon transformation.This study explores the mechanism of the synergistic effect of optimizing aggregate fractal grading and intro...Mine filling materials urgently need to improve mechanical properties and achieve low-carbon transformation.This study explores the mechanism of the synergistic effect of optimizing aggregate fractal grading and introducing CO_(2)nanobubble technology to improve the performance of cement-fly ash-based backfill materials(CFB).The properties including fluidity,setting time,uniaxial compressive strength,elastic modulus,porosity,microstructure and CO_(2)storage performance were systematically studied through methods such as fluidity evaluation,time test,uniaxial compression test,mercury intrusion porosimetry(MIP),scanning electron microscopy-energy dispersive spectroscopy analysis(SEM-EDS),and thermogravimetric-differential thermogravimetric analysis(TG-DTG).The experimental results show that the density and strength of the material are significantly improved under the synergistic effect of fractal dimension and CO_(2)nanobubbles.When the fractal dimension reaches 2.65,the mass ratio of coarse and fine aggregates reaches the optimal balance,and the structural density is greatly improved at the same time.At this time,the uniaxial compressive strength and elastic modulus reach their peak values,with increases of up to 13.46%and 27.47%,respectively.CO_(2)nanobubbles enhance the material properties by promoting hydration reaction and carbonization.At the microscopic level,CO_(2)nanobubble water promotes the formation of C-S-H(hydrated calcium silicate),C-A-S-H(hydrated calcium aluminium silicate)gel and CaCO_(3),which is the main way to enhance the performance.Thermogravimetric studies have shown that when the fractal dimension is 2.65,the dehydration of hydration products and the decarbonization process of CaCO_(3)are most obvious,and CO_(2)nanobubble water promotes the carbonization reaction,making it surpass the natural state.The CO_(2)sequestration quality of cement-fly ash-based materials treated with CO_(2)nanobubble water at different fractal dimensions increased by 12.4wt%to 99.8wt%.The results not only provide scientific insights for the design and implementation of low-carbon filling materials,but also provide a solid theoretical basis for strengthening green mining practices and promoting sustainable resource utilization.展开更多
Nanoelectronic devices are being extensively developed in these years with a large variety of potential applications. In this article, some recent developments in nanoelectronic devices, including their principles, st...Nanoelectronic devices are being extensively developed in these years with a large variety of potential applications. In this article, some recent developments in nanoelectronic devices, including their principles, structures and potential applications are reviewed. As nanodevices work in nanometer dimensions, they consume much less power and function much faster than conventional microelectronic devices. Nanoelectronic devices can operate in different principles so that they can be further grouped into field emission devices,molecular devices, quantum devices, etc. Nanodevices can function as sensors, diodes, transistors, photovoltaic and light emitting devices, etc. Recent advances in both theoretical simulation and fabrication technologies expedite the development process from device design to prototype demonstration. Practical applications with a great market value from nanoelectronic devices are expected in near future.展开更多
Traditional digital processing approaches are based on semiconductor transistors, which suffer from high power consumption, aggravating with technology node scaling. To solve definitively this problem, a number of eme...Traditional digital processing approaches are based on semiconductor transistors, which suffer from high power consumption, aggravating with technology node scaling. To solve definitively this problem, a number of emerging non-volatile nanodevices are under intense investigations. Meanwhile, novel computing circuits are invented to dig the full potential of the nanodevices. The combination of non-volatile nanodevices with suitable computing paradigms have many merits compared with the complementary metal-oxide-semiconductor transistor （CMOS） technology based structures, such as zero standby power, ultra-high density, non-volatility, and acceptable access speed. In this paper, we overview and compare the computing paradigms based on the emerging nanodevices towards ultra-low dissipation.展开更多
The photoconductive response of the fundamental type of diodic nanodevice comprising a low resistivity, n-type epitaxial layer and a semi-insulating substrate is considered in terms of the optoelectronic parameter of ...The photoconductive response of the fundamental type of diodic nanodevice comprising a low resistivity, n-type epitaxial layer and a semi-insulating substrate is considered in terms of the optoelectronic parameter of photoconductive gain as experimentally measurable through monitoring the temporal evolution of conductivity current photoenhancement under continuous epilayer illumination-exposure. A modelling taking into account the built-in potential barrier of the interface of the epitaxial layer/substrate device (ESD) as well as its modification by the photovoltage induced within the illuminated ESD diode leads to predicting the technologically exploitable possibility of a notably slow photonic dose-evolution (exposure time-development) of the optonanoelectronics ESD photoconductive gain.展开更多
We investigate the Fano factor in a strained armchair and zigzag graphene nanoribbon nanodevice under the effect of ac field in a wide range of frequencies at different temperatures （10？K–70？K）. This nanodevice i...We investigate the Fano factor in a strained armchair and zigzag graphene nanoribbon nanodevice under the effect of ac field in a wide range of frequencies at different temperatures （10？K–70？K）. This nanodevice is modeled as follows： a graphene nanoribbon is connected to two metallic leads. These two metallic leads operate as a source and a drain. The conducting substance is the gate electrode in this three-terminal nanodevice. Another metallic gate is used to govern the electrostatics and the switching of the graphene nanoribbon channel. The substances at the graphene nanoribbon/metal contact are controlled by the back gate. The photon-assisted tunneling probability is deduced by solving the Dirac eigenvalue differential equation in which the Fano factor is expressed in terms of this tunneling probability. The results show that for the investigated nanodevice, the Fano factor decreases as the frequency of the induced ac field increases, while it increases as the temperature increases. In general, the Fano factors for both strained armchair and zigzag graphene nanoribbons are different. This is due to the effect of the uniaxial strain. It is shown that the band structure parameters of graphene nanoribbons at the energy gap, the C–C bond length, the hopping integral, the Fermi energy and the width are modulated by uniaxial strain. This research gives us a promise of the present nanodevice being used for digital nanoelectronics and sensors.展开更多
基金financially supported by the National Key Research and Development Program(2022YFE0127400)the National Natural Science Foundation of China(52172040,52202041,and U23B2077)+1 种基金Taishan Scholar Project of Shandong Province(tsqn202211086,ts202208832,tsqnz20221118)the Fundamental Research Funds for the Central Universities(23CX06055A).
文摘Micro silicon(mSi)is a promising anode candidate for all-solid-state batteries due to its high specific capacity,low side reactions,and high tap density.However,silicon suffers from its poor electronic and ionic conductivity,which is particularly severe on a micro scale and in solid-state systems,leading to increased polarization and inferior electrochemical performance.Doping can broaden the transmission pathways and reduce the diffusion energy barrier for electrons and lithium ions.However,achieving effective,uniform doping in mSi is challenging due to its longer diffusion paths and higher energy barriers.Therefore,current doping research is primarily limited to nanosilicon.In this study,we successfully used a Joule-heating activated staged thermal treatment to achieve full-depth doping of germanium(Ge)in the mSi substrate.The Joule-heating process activated the mSi substrate,resulting in abundant vacancy defects that reduced the diffusion barrier of Ge into the silicon lattice and facilitated full-depth Ge doping.Surprisingly,the resulting Si-Ge anode exhibited significantly enhanced electrical conductivity(70 times).Meanwhile,the improved Li-ion conductivity in mSi and the reduced Young’s modulus enhance the electrode reaction kinetics and integrity after cycling.Ge-doped silicon anodes demonstrate excellent electrochemical performance when applied in sulfide solid-state half-cells and full-cells.This work provides substantial insights into the rational structural design of mSi alloyed anode materials,paving the way for the development of high-performance solid-state Li-ion batteries.
基金supported by Young Elite Scientists Sponsorship Program by China Association for Science and Technology(No.2022QNRC001)the National Natural Science Foundation of China(No.52273053)the Chenguang Program of Shanghai Education Development Foundation and Shanghai Municipal Education Commission(No.21CGA41)。
文摘Extreme cold weather seriously harms human thermoregulatory system,necessitating high-performance insulating garments to maintain body temperature.However,as the core insulating layer,advanced fibrous materials always struggle to balance mechanical properties and thermal insulation,resulting in their inability to meet the demands for both washing resistance and personal protection.Herein,inspired by the natural spring-like structures of cucumber tendrils,a superelastic and washable micro/nanofibrous sponge(MNFS)based on biomimetic helical fibers is directly prepared utilizing multiple-jet electrospinning technology for high-performance thermal insulation.By regulating the conductivity of polyvinylidene fluoride solution,multiple-jet ejection and multiple-stage whipping of jets are achieved,and further control of phase separation rates enables the rapid solidification of jets to form spring-like helical fibers,which are directly entangled to assemble MNFS.The resulting MNFS exhibits superelasticity that can withstand large tensile strain(200%),1000 cyclic tensile or compression deformations,and retain good resilience even in liquid nitrogen(-196℃).Furthermore,the MNFS shows efficient thermal insulation with low thermal conductivity(24.85 mW m^(-1)K^(-1)),close to the value of dry air,and remains structural stability even after cyclic washing.This work offers new possibilities for advanced fibrous sponges in transportation,environmental,and energy applications.
基金supported by the National Natural Science Foundation of China(22168008,22378085)the Guangxi Natural Science Foundation(2024GXNSFDA010053)+1 种基金the Technology Development Project of Guangxi Bossco Environmental Protection Technology Co.,Ltd(202100039)Innovation Project of Guangxi Graduate Education(YCBZ2024065).
文摘Strategically coupling nanoparticle hybrids and internal thermosensitive molecular switches establishes an innovative paradigm for constructing micro/nanoscale-reconfigurable robots,facilitating energyefficient CO_(2) management in life-support systems of confined space.Here,a micro/nano-reconfigurable robot is constructed from the CO_(2) molecular hunters,temperature-sensitive molecular switch,solar photothermal conversion,and magnetically-driven function engines.The molecular hunters within the molecular extension state can capture 6.19 mmol g^(−1) of CO_(2) to form carbamic acid and ammonium bicarbonate.Interestingly,the molecular switch of the robot activates a molecular curling state that facilitates CO_(2) release through nano-reconfiguration,which is mediated by the temperature-sensitive curling of Pluronic F127 molecular chains during the photothermal desorption.Nano-reconfiguration of robot alters the amino microenvironment,including increasing surface electrostatic potential of the amino group and decreasing overall lowest unoccupied molecular orbital energy level.This weakened the nucleophilic attack ability of the amino group toward the adsorption product derivatives,thereby inhibiting the side reactions that generate hard-to-decompose urea structures,achieving the lowest regeneration temperature of 55℃ reported to date.The engine of the robot possesses non-contact magnetically-driven micro-reconfiguration capability to achieve efficient photothermal regeneration while avoiding local overheating.Notably,the robot successfully prolonged the survival time of mice in the sealed container by up to 54.61%,effectively addressing the issue of carbon suffocation in confined spaces.This work significantly enhances life-support systems for deep-space exploration,while stimulating innovations in sustainable carbon management technologies for terrestrial extreme environments.
基金financially supported by the China Scholarship Council(CSC)。
文摘Mine filling materials urgently need to improve mechanical properties and achieve low-carbon transformation.This study explores the mechanism of the synergistic effect of optimizing aggregate fractal grading and introducing CO_(2)nanobubble technology to improve the performance of cement-fly ash-based backfill materials(CFB).The properties including fluidity,setting time,uniaxial compressive strength,elastic modulus,porosity,microstructure and CO_(2)storage performance were systematically studied through methods such as fluidity evaluation,time test,uniaxial compression test,mercury intrusion porosimetry(MIP),scanning electron microscopy-energy dispersive spectroscopy analysis(SEM-EDS),and thermogravimetric-differential thermogravimetric analysis(TG-DTG).The experimental results show that the density and strength of the material are significantly improved under the synergistic effect of fractal dimension and CO_(2)nanobubbles.When the fractal dimension reaches 2.65,the mass ratio of coarse and fine aggregates reaches the optimal balance,and the structural density is greatly improved at the same time.At this time,the uniaxial compressive strength and elastic modulus reach their peak values,with increases of up to 13.46%and 27.47%,respectively.CO_(2)nanobubbles enhance the material properties by promoting hydration reaction and carbonization.At the microscopic level,CO_(2)nanobubble water promotes the formation of C-S-H(hydrated calcium silicate),C-A-S-H(hydrated calcium aluminium silicate)gel and CaCO_(3),which is the main way to enhance the performance.Thermogravimetric studies have shown that when the fractal dimension is 2.65,the dehydration of hydration products and the decarbonization process of CaCO_(3)are most obvious,and CO_(2)nanobubble water promotes the carbonization reaction,making it surpass the natural state.The CO_(2)sequestration quality of cement-fly ash-based materials treated with CO_(2)nanobubble water at different fractal dimensions increased by 12.4wt%to 99.8wt%.The results not only provide scientific insights for the design and implementation of low-carbon filling materials,but also provide a solid theoretical basis for strengthening green mining practices and promoting sustainable resource utilization.
基金supported by National High Technology Research and Development Program of China(No.2011AA050504)Shanghai Science and Technology Grant (No.12nm0503800 and No.12nm0503500)the Analytical and Testing Center of SJTU
文摘Nanoelectronic devices are being extensively developed in these years with a large variety of potential applications. In this article, some recent developments in nanoelectronic devices, including their principles, structures and potential applications are reviewed. As nanodevices work in nanometer dimensions, they consume much less power and function much faster than conventional microelectronic devices. Nanoelectronic devices can operate in different principles so that they can be further grouped into field emission devices,molecular devices, quantum devices, etc. Nanodevices can function as sensors, diodes, transistors, photovoltaic and light emitting devices, etc. Recent advances in both theoretical simulation and fabrication technologies expedite the development process from device design to prototype demonstration. Practical applications with a great market value from nanoelectronic devices are expected in near future.
文摘Traditional digital processing approaches are based on semiconductor transistors, which suffer from high power consumption, aggravating with technology node scaling. To solve definitively this problem, a number of emerging non-volatile nanodevices are under intense investigations. Meanwhile, novel computing circuits are invented to dig the full potential of the nanodevices. The combination of non-volatile nanodevices with suitable computing paradigms have many merits compared with the complementary metal-oxide-semiconductor transistor （CMOS） technology based structures, such as zero standby power, ultra-high density, non-volatility, and acceptable access speed. In this paper, we overview and compare the computing paradigms based on the emerging nanodevices towards ultra-low dissipation.
文摘The photoconductive response of the fundamental type of diodic nanodevice comprising a low resistivity, n-type epitaxial layer and a semi-insulating substrate is considered in terms of the optoelectronic parameter of photoconductive gain as experimentally measurable through monitoring the temporal evolution of conductivity current photoenhancement under continuous epilayer illumination-exposure. A modelling taking into account the built-in potential barrier of the interface of the epitaxial layer/substrate device (ESD) as well as its modification by the photovoltage induced within the illuminated ESD diode leads to predicting the technologically exploitable possibility of a notably slow photonic dose-evolution (exposure time-development) of the optonanoelectronics ESD photoconductive gain.
文摘We investigate the Fano factor in a strained armchair and zigzag graphene nanoribbon nanodevice under the effect of ac field in a wide range of frequencies at different temperatures （10？K–70？K）. This nanodevice is modeled as follows： a graphene nanoribbon is connected to two metallic leads. These two metallic leads operate as a source and a drain. The conducting substance is the gate electrode in this three-terminal nanodevice. Another metallic gate is used to govern the electrostatics and the switching of the graphene nanoribbon channel. The substances at the graphene nanoribbon/metal contact are controlled by the back gate. The photon-assisted tunneling probability is deduced by solving the Dirac eigenvalue differential equation in which the Fano factor is expressed in terms of this tunneling probability. The results show that for the investigated nanodevice, the Fano factor decreases as the frequency of the induced ac field increases, while it increases as the temperature increases. In general, the Fano factors for both strained armchair and zigzag graphene nanoribbons are different. This is due to the effect of the uniaxial strain. It is shown that the band structure parameters of graphene nanoribbons at the energy gap, the C–C bond length, the hopping integral, the Fermi energy and the width are modulated by uniaxial strain. This research gives us a promise of the present nanodevice being used for digital nanoelectronics and sensors.
