The transport of sub-picosecond laser-driven fast electrons in nanopore array targets is studied.Attributed to the generation of micro-structured magnetic fields,most fast electron beams are proven to be effectively g...The transport of sub-picosecond laser-driven fast electrons in nanopore array targets is studied.Attributed to the generation of micro-structured magnetic fields,most fast electron beams are proven to be effectively guided and restricted during the propagation.Different transport patterns of fast electrons in the targets are observed in experiments and reproduced by particle-in-cell simulations,representing two components:initially collimated low-energy electrons in the center and high-energy scattering electrons turning into surrounding annular beams.The critical energy for confined electrons is deduced theoretically.The electron guidance and confinement by the nano-structured targets offer a technological approach to manipulate and optimize the fast electron transport by properly modulating pulse parameters and target design,showing great potential in many applications including ion acceleration,microfocus x-ray sources and inertial confinement fusion.展开更多
The use of a novel double-cone funnel target with high density layers （HDL） to collimate and focus electrons is investigated by two-dimensional particle-in-cell simulations. The proposed scheme can guide, collimate ...The use of a novel double-cone funnel target with high density layers （HDL） to collimate and focus electrons is investigated by two-dimensional particle-in-cell simulations. The proposed scheme can guide, collimate and focus electron beams to smaller sizes. The collimation reasons are analyzed by the quasi-static magnetic fields generation inside the beam collimator with HDL. It is found that the energy conversion efficiency is increased by a factor of 2.2 in this new scheme in comparison with the that without HDL. Such a target structure has potential for design flexibility and prevents inefficiencies in important applications such as fast ignition, etc.展开更多
MIL-101(Cr)is a promising moisture absorbent for solar-driven water harvesting from moisture to tackle the worldwide water shortage issue.However,the MIL-101(Cr)powder suffers from a long ab/desorption cycle due to th...MIL-101(Cr)is a promising moisture absorbent for solar-driven water harvesting from moisture to tackle the worldwide water shortage issue.However,the MIL-101(Cr)powder suffers from a long ab/desorption cycle due to the crystal aggregation caused by its inherent powder properties.Here,we demonstrate a MIL-101(Cr)nanofibrous composite membrane with a nanofibrous matrix where MIL-101(Cr)is monodisperse in the 3D porous nanofibrous matrix through a simple spray-electrospinning strategy.The continuous porous nanofibrous matrix not only offers sufficient sites for MIL-101(Cr)loading but also provides rapid moisture transport channels,resulting in a super-rapid ab/desorption duration of 50 min(including an absorption process for 40 min and a desorption process for 10 min)and multicycle daily water production of 15.9 L kg^(−1) d^(−1).Besides,the MIL-101(Cr)nanofibrous composite membrane establishes a high solar absorption of 92.8%,and excellent photothermal conversion with the surface temperature of 70.7°C under one-sun irradiation.In addition,the MIL-101(Cr)nanofibrous composite membrane shows excellent potential for practical application due to its flexibility,portability,and use stability.This work provides a new perspective of shortening MOF ab/desorption duration by introducing a porous nanofibrous matrix to improve the specific water production for the solar-driven ab/desorption water harvesting technique.展开更多
Exploring the desired anode materials to address the issues of poor structural stability tardy redox kinetics caused by large potassium ionic radius are fatal for the realization of large-scale applications of potassi...Exploring the desired anode materials to address the issues of poor structural stability tardy redox kinetics caused by large potassium ionic radius are fatal for the realization of large-scale applications of potassium-ion batteries.In this work,the feasibility to achieve promoted K^(+)storage by constructing the model of CoS_(2)enfolded in carbon was verified by the density functional theory calculations.And the results predicted a faster electron/potassium ion transport kinetics than bare CoS_(2)by increasing electron carrier density and narrowing diffusion barrier.Therefore,an interfacial engineering strategy was applied and implemented to synthesize the CoS_(2)nanoparticles enveloped in the S-doped carbon(CoS_(2)/SC)under this inspiration.The as-prepared CoS_(2)/SC composite exhibited a prominent rate capability and long cycling lifespan,delivering the high capacity of 375 mA h g^(-1)at 0.2 A g^(-1)at the 100th cycle and 273 mA h g^(-1)at 2 A g^(-1)over 300 cycles.The in/ex situ characterizations unraveled the converse mechanism of CoS_(2)/SC in K^(+)storage,showing an eventually reversible phase transformation of K_(x)CoS_(2)Co↔within the electrochemical reactions.展开更多
基金supported by the National Key R&D Program of China(Grant No.2016YFA0401100)the Science and Technology on Plasma Physics Laboratory(Grant Nos.6142A04180201 and JCKYS2020212006)+1 种基金National Natural Science Foundation of China(Grant No.11975214)the Science Challenge Program(Grant Nos.TZ2016005 and TZ2018005)
文摘The transport of sub-picosecond laser-driven fast electrons in nanopore array targets is studied.Attributed to the generation of micro-structured magnetic fields,most fast electron beams are proven to be effectively guided and restricted during the propagation.Different transport patterns of fast electrons in the targets are observed in experiments and reproduced by particle-in-cell simulations,representing two components:initially collimated low-energy electrons in the center and high-energy scattering electrons turning into surrounding annular beams.The critical energy for confined electrons is deduced theoretically.The electron guidance and confinement by the nano-structured targets offer a technological approach to manipulate and optimize the fast electron transport by properly modulating pulse parameters and target design,showing great potential in many applications including ion acceleration,microfocus x-ray sources and inertial confinement fusion.
基金supported by National Natural Science Foundation of China(NSFC)under Grant Nos.11475026,11664039 and 11305010
文摘The use of a novel double-cone funnel target with high density layers （HDL） to collimate and focus electrons is investigated by two-dimensional particle-in-cell simulations. The proposed scheme can guide, collimate and focus electron beams to smaller sizes. The collimation reasons are analyzed by the quasi-static magnetic fields generation inside the beam collimator with HDL. It is found that the energy conversion efficiency is increased by a factor of 2.2 in this new scheme in comparison with the that without HDL. Such a target structure has potential for design flexibility and prevents inefficiencies in important applications such as fast ignition, etc.
基金This work was partly supported by the Funda-mental Research Funds for the Central Universi-ties (2232020D-15,2232020A-08,2232020G-01,2232020D-14,and 2232019D3-11)grants (51773037,51973027,51803023,52003044,and 61771123)from the National Natural Science Foundation of China+3 种基金This work has also been supported by the Chang Jiang Scholars Program and the Innovation Program of Shanghai Munici-pal Education Commission (2019-01-07-00-03-E00023)to Prof.Xiaohong Qinthe Shanghai Sailing Program (19YF1400700)the Opening Project of State Key Laboratory of High-Performance Ceramics and Superfine Microstruc-ture (SKL201906SIC)Young Elite Scientists Sponsorship Program by CAST and DHU Distin-guished Young Professor Program to Prof.Liming Wang.
文摘MIL-101(Cr)is a promising moisture absorbent for solar-driven water harvesting from moisture to tackle the worldwide water shortage issue.However,the MIL-101(Cr)powder suffers from a long ab/desorption cycle due to the crystal aggregation caused by its inherent powder properties.Here,we demonstrate a MIL-101(Cr)nanofibrous composite membrane with a nanofibrous matrix where MIL-101(Cr)is monodisperse in the 3D porous nanofibrous matrix through a simple spray-electrospinning strategy.The continuous porous nanofibrous matrix not only offers sufficient sites for MIL-101(Cr)loading but also provides rapid moisture transport channels,resulting in a super-rapid ab/desorption duration of 50 min(including an absorption process for 40 min and a desorption process for 10 min)and multicycle daily water production of 15.9 L kg^(−1) d^(−1).Besides,the MIL-101(Cr)nanofibrous composite membrane establishes a high solar absorption of 92.8%,and excellent photothermal conversion with the surface temperature of 70.7°C under one-sun irradiation.In addition,the MIL-101(Cr)nanofibrous composite membrane shows excellent potential for practical application due to its flexibility,portability,and use stability.This work provides a new perspective of shortening MOF ab/desorption duration by introducing a porous nanofibrous matrix to improve the specific water production for the solar-driven ab/desorption water harvesting technique.
基金The National Natural Science Foundation of China(Grant No.21701144)Opening Foundation of State Key Laboratory of Chemistry and Utilization of Carbon-based Energy Resource of Xinjiang University(Grant No.KFKT2021004)are gratefully acknowledged.
文摘Exploring the desired anode materials to address the issues of poor structural stability tardy redox kinetics caused by large potassium ionic radius are fatal for the realization of large-scale applications of potassium-ion batteries.In this work,the feasibility to achieve promoted K^(+)storage by constructing the model of CoS_(2)enfolded in carbon was verified by the density functional theory calculations.And the results predicted a faster electron/potassium ion transport kinetics than bare CoS_(2)by increasing electron carrier density and narrowing diffusion barrier.Therefore,an interfacial engineering strategy was applied and implemented to synthesize the CoS_(2)nanoparticles enveloped in the S-doped carbon(CoS_(2)/SC)under this inspiration.The as-prepared CoS_(2)/SC composite exhibited a prominent rate capability and long cycling lifespan,delivering the high capacity of 375 mA h g^(-1)at 0.2 A g^(-1)at the 100th cycle and 273 mA h g^(-1)at 2 A g^(-1)over 300 cycles.The in/ex situ characterizations unraveled the converse mechanism of CoS_(2)/SC in K^(+)storage,showing an eventually reversible phase transformation of K_(x)CoS_(2)Co↔within the electrochemical reactions.
