We use the High-energy Electron Experiments(HEP)instrument onboard Arase(ERG)to conduct an energy-dependent cross-satellite calibration of electron fluxes measured by the High Energy Particle Detector(HEPD)onboard Fen...We use the High-energy Electron Experiments(HEP)instrument onboard Arase(ERG)to conduct an energy-dependent cross-satellite calibration of electron fluxes measured by the High Energy Particle Detector(HEPD)onboard FengYun-4A(FY-4A)spanning from April 1,2017,to September 30,2019.By tracing the two-dimensional magnetic positions(L,magnetic local time[MLT])of FY-4A at each time,we compare the datasets of the conjugate electron fluxes over the range of 245–894 keV in 6 energy channels for the satellite pair within different sets of L×MLT.The variations in the electron fluxes observed by FY-4A generally agree with the Arase measurements,and the percentages of the ratios of electron flux conjunctions within a factor of 2 are larger than 50%.Compared with Arase,FY-4A systematically overestimates electron fluxes at all 6 energy channels,with the corresponding calibration factors ranging from 0.67 to 0.81.After the cross-satellite calibration,the electron flux conjunctions between FY-4A and Arase show better agreement,with much smaller normalized root mean square errors.Our results provide a valuable reference for the application of FY-4A high-energy electron datasets to in-depth investigations of the Earth’s radiation belt electron dynamics.展开更多
Surface segregation is studied via the evolution of reflection high-energy electron diffraction (RHEED) patterns under different values of As4 BEP for InGaAs films. When the As4 BEP is set to be zero, the RHEED patt...Surface segregation is studied via the evolution of reflection high-energy electron diffraction (RHEED) patterns under different values of As4 BEP for InGaAs films. When the As4 BEP is set to be zero, the RHEED pattern keeps a 4x3/(nx3) structure with increasing temperature, and surface segregation takes place until 470 ℃ The RHEED pattern develops into a metal-rich (4x2) structure as temperature increases to 495℃. The reason for this is that surface segregation makes the In inside the InGaAs film climb to its surface. With the temperature increasing up to 515℃, the RHEED pattern turns into a GaAs(2x4) structure due to In desorption. While the As4 BEP comes up to a specific value (1.33 x 10-4 Pa-1.33 x 10-3 Pa), the surface temperature can delay the segregation and desorption. We find that As4 BEP has a big influence on surface desorption, while surface segregation is more strongly dependent on temperature than surface desorption.展开更多
Various aspects of the influence of the quasi-real photons and the Coulomb resonances on the formation of the crosssection of inelastic scattering of high energy electrons on atomic nuclei are investigated. Emiss is t...Various aspects of the influence of the quasi-real photons and the Coulomb resonances on the formation of the crosssection of inelastic scattering of high energy electrons on atomic nuclei are investigated. Emiss is the energy that disappears in the processes of knocking-on of protons in the reactions . A new hypothesis that interprets the origin of the energy losses is proposed. Specific experiments that can confirm or refute this hypothesis are proposed as well. The “regularized” cross-sections of electro-disintegration of nuclei by high-energy electrons are calculated in the framework of the nuclear shell model. It is shown that for the experimental verification of the existence of Coulomb resonances, it is necessary to investigate the processes at relatively small angles of scattering. The peculiarities of numerical methods that are crucial in the investigation of inelastic scattering of high-energy electrons on nuclei in the framework of the nuclear shell model are analyzed in this work as well. The cross-sections of the scattering of high-energy electrons on the angle are calculated. It is shown that the orthogonality of the wave functions of a knocked-on proton in the initial and final states plays an important role in the interpretation of this process.展开更多
Using the model of the inverse Compton scattering between high-energy electrons and heat-radiation photons, the influence of heat-radiating photons on multi-photon Compton scattering high-energy electrons is studied ....Using the model of the inverse Compton scattering between high-energy electrons and heat-radiation photons, the influence of heat-radiating photons on multi-photon Compton scattering high-energy electrons is studied . The results show that the energy loss, power loss, light resistance and light pressure of the high-energy electron formed by heat radiating are all proportional to the temperature T4 of the vacuum cavity of the electron,the Lorentz factor γ2 of the high-energy electrons, the scattering section of the electron and the number of photons acting at the same time with high-energy electrons. A good method for lessening the energy loss of the high-energy electron by using the one-photon Compton scattering between high-energy electrons and heat radiation photons is proposed.展开更多
A gridded thermionic cathode electron gun was developed for the linear accelerator of the High Energy Photon Source(HEPS).An electron gun should provide a large maximum bunch charge with a wide adjustable range.To sat...A gridded thermionic cathode electron gun was developed for the linear accelerator of the High Energy Photon Source(HEPS).An electron gun should provide a large maximum bunch charge with a wide adjustable range.To satisfy these requirements,the shape of the electrode was optimized using a multi-objective genetic algorithm.A large bunch charge with an adjustable range was achieved using the grid-limited gun,the flow of which was analyzed using 3-D simulations.The electron gun has been manufactured and tested,and the measured data of the grid-limited current and simulation results are compared and discussed in this study.展开更多
High-performance ion-conducting hydrogels(ICHs)are vital for developing flexible electronic devices.However,the robustness and ion-conducting behavior of ICHs deteriorate at extreme tempera-tures,hampering their use i...High-performance ion-conducting hydrogels(ICHs)are vital for developing flexible electronic devices.However,the robustness and ion-conducting behavior of ICHs deteriorate at extreme tempera-tures,hampering their use in soft electronics.To resolve these issues,a method involving freeze–thawing and ionizing radiation technology is reported herein for synthesizing a novel double-network(DN)ICH based on a poly(ionic liquid)/MXene/poly(vinyl alcohol)(PMP DN ICH)system.The well-designed ICH exhibits outstanding ionic conductivity(63.89 mS cm^(-1) at 25℃),excellent temperature resistance(-60–80℃),prolonged stability(30 d at ambient temperature),high oxidation resist-ance,remarkable antibacterial activity,decent mechanical performance,and adhesion.Additionally,the ICH performs effectively in a flexible wireless strain sensor,thermal sensor,all-solid-state supercapacitor,and single-electrode triboelectric nanogenerator,thereby highlighting its viability in constructing soft electronic devices.The highly integrated gel structure endows these flexible electronic devices with stable,reliable signal output performance.In particular,the all-solid-state supercapacitor containing the PMP DN ICH electrolyte exhibits a high areal specific capacitance of 253.38 mF cm^(-2)(current density,1 mA cm^(-2))and excellent environmental adaptability.This study paves the way for the design and fabrication of high-performance mul-tifunctional/flexible ICHs for wearable sensing,energy-storage,and energy-harvesting applications.展开更多
The poor stability of RuO_(2)electrocatalysts has been the primary obstacles for their practical application in polymer electrolyte membrane electrolyzers.To dramatically enhance the durability of RuO_(2)to construct ...The poor stability of RuO_(2)electrocatalysts has been the primary obstacles for their practical application in polymer electrolyte membrane electrolyzers.To dramatically enhance the durability of RuO_(2)to construct activity-stability trade-off model is full of significance but challenging.Herein,a single atom Zn stabilized RuO_(2)with enriched oxygen vacancies(SA Zn-RuO_(2))is developed as a promising alternative to iridium oxide for acidic oxygen evolution reaction(OER).Compared with commercial RuO_(2),the enhanced Ru–O bond strength of SA Zn-RuO_(2)by forming Zn-O-Ru local structure motif is favorable to stabilize surface Ru,while the electrons transferred from Zn single atoms to adjacent Ru atoms protects the Ru active sites from overoxidation.Simultaneously,the optimized surrounding electronic structure of Ru sites in SA ZnRuO_(2)decreases the adsorption energies of OER intermediates to reduce the reaction barrier.As a result,the representative SA Zn-RuO_(2)exhibits a low overpotential of 210 mV to achieve 10 mA cm^(-2)and a greatly enhanced durability than commercial RuO_(2).This work provides a promising dual-engineering strategy by coupling single atom doping and vacancy for the tradeoff of high activity and catalytic stability toward acidic OER.展开更多
Stretchable electronics are crucial enablers for next-generation wearables intimately integrated into the human body.As the primary compliant conductors used in these devices,metallic nanostructure/elastomer composite...Stretchable electronics are crucial enablers for next-generation wearables intimately integrated into the human body.As the primary compliant conductors used in these devices,metallic nanostructure/elastomer composites often struggle to form conformal contact with the textured skin.Hybrid electrodes have been consequently developed based on conductive nanocomposite and soft hydrogels to establish seamless skin-device interfaces.However,chemical modifications are typically needed for reliable bonding,which can alter their original properties.To overcome this limitation,this study presents a facile fabrication approach for mechanically interlocked nanocomposite/hydrogel hybrid electrodes.In this physical process,soft microfoams are thermally laminated on silver nanowire nanocomposites as a porous interface,which forms an interpenetrating network with the hydrogel.The microfoam-enabled bonding strategy is generally compatible with various polymers.The resulting interlocked hybrids have a 28-fold improved interfacial toughness compared to directly stacked hybrids.These electrodes achieve firm attachment to the skin and low contact impedance using tissue-adhesive hydrogels.They have been successfully integrated into an epidermal sleeve to distinguish hand gestures by sensing mus-cle contractions.Interlocked nanocomposite/hydrogel hybrids reported here offer a promising platform to combine the benefits of both materials for epidermal devices and systems.展开更多
The sensory perception of food is a dynamic process,which is closely related to the release of flavor substances during oral processing.It’s not only affected by the food material,but also subjected to the individual...The sensory perception of food is a dynamic process,which is closely related to the release of flavor substances during oral processing.It’s not only affected by the food material,but also subjected to the individual oral environment.To explore the oral processing characteristics of soft-boiled chicken,the sensory properties,texture,particle size,viscosity,characteristic values of electronic nose and tongue of different chicken samples were investigated.The correlation analysis showed that the physical characteristics especially the cohesiveness,springiness,resilience of the sample determined oral processing behavior.The addition of chicken skin played a role in lubrication during oral processing.The particle size of the bolus was heightened at the early stage,and the fluidity was enhanced in the end,which reduced the chewing time to the swallowing point and raised the aromatic compounds signal of electronic nose.But the effect of chicken skin on chicken thigh with relatively high fat content,was opposite in electronic nose,which had a certain masking effect on the perception of umami and sweet taste.In conclusion,fat played a critical role in chicken oral processing and chicken thigh had obvious advantages in comprehensive evaluation of soft-boiled chicken,which was more popular among people.展开更多
The existence of a significant electron drift instability(EDI) in the Hall thruster is considered as one of the possible causes of the abnormal increase in axial electron mobility near the outlet of the channel. In re...The existence of a significant electron drift instability(EDI) in the Hall thruster is considered as one of the possible causes of the abnormal increase in axial electron mobility near the outlet of the channel. In recent years, extensive simulation research on the characteristics of EDI has been conducted, but the excitation mechanism and growth mechanism of EDI in linear stage and nonlinear stage remain unclear. In this work, a one-dimensional PIC model in the azimuthal direction of the thruster near-exit region is established to gain further insights into the mechanism of the EDI in detail, and the effects of different types of propellants on EDI characteristics are discussed. The changes in axial electron transport caused by EDI under different types of propellants and electromagnetic field strengths are also examined. The results indicate that EDI undergoes a short linear growth phase before transitioning to the nonlinear phase and finally reaching saturation through the ion Landau damping. The EDI drives a significant ion heating in the azimuthal direction through electron–ion friction before entering the quasi-steady state, which increases the axial mobility of the electrons. Using lighter atomic weight propellant can effectively suppress the oscillation amplitude of EDI, but it will increase the linear growth rate, frequency, and phase velocity of EDI. Compared with the classical mobility, the axial electron mobility under the EDI increases by three orders of magnitude, which is consistent with experimental phenomena. The change of propellant type is insufficient to significantly change the axial electron mobility. It is also found that the collisions between electrons and neutral gasescan significantly affect the axial electron mobility under the influence of EDI, and lead the strength of the electric field to increase and the strength of the magnetic field to decrease, thereby both effectively suppressing the axial transport of electrons.展开更多
This review summarizes recent progress in developing wireless,batteryless,fully implantable biomedical devices for real-time continuous physiological signal monitoring,focusing on advancing human health care.Design co...This review summarizes recent progress in developing wireless,batteryless,fully implantable biomedical devices for real-time continuous physiological signal monitoring,focusing on advancing human health care.Design considerations,such as biological constraints,energy sourcing,and wireless communication,are discussed in achieving the desired performance of the devices and enhanced interface with human tissues.In addition,we review the recent achievements in materials used for developing implantable systems,emphasizing their importance in achieving multi-functionalities,biocompatibility,and hemocompatibility.The wireless,batteryless devices offer minimally invasive device insertion to the body,enabling portable health monitoring and advanced disease diagnosis.Lastly,we summarize the most recent practical applications of advanced implantable devices for human health care,highlighting their potential for immediate commercialization and clinical uses.展开更多
Hydride ion(H-)conductors have drawn much attention due to their potential applications in hydrideion-based devices.Rare earth metal hydrides(REH_(x))have fast H-conduction which,unfortunately,is accompanied by detrim...Hydride ion(H-)conductors have drawn much attention due to their potential applications in hydrideion-based devices.Rare earth metal hydrides(REH_(x))have fast H-conduction which,unfortunately,is accompanied by detrimental electron conduction preventing their application as ion conductors.Here,REH_(x)(RE=Nd,Ce,and Pr)with varied grain sizes,rich grain boundaries,and defects have been prepared by ball milling and subsequent sintering.The electronic conductivity of the ball-milled REH_(x)samples can be reduced by 2-4 orders of magnitude compared with the non-ball-milled samples.The relationship of electron conduction and miscrostructures in REH_(x)is studied and discussed based on experimental data and previously-proposed classical and quantum theories.The H-conductivity of all REH_(x)is about 10^(-4)to 10^(-3)S cm^(-1)at room temperature,showing promise for the development of H-conductors and their applications in clean energy storage and conversion.展开更多
The nucleation and growth mechanism of nanoparticles is an important theory,which can guide the preparation of nanomaterials.However,it is still lacking in direct observation on the details of the evolution of interme...The nucleation and growth mechanism of nanoparticles is an important theory,which can guide the preparation of nanomaterials.However,it is still lacking in direct observation on the details of the evolution of intermediate state structure during nucleation and growth.In this work,the evolution process of bismuth nanoparticles induced by electron beam was revealed by in-situ transmission electron microscopy(TEM)at atomic scale.The experimental results demonstrate that the size,stable surface and crystallographic defect have important influences on the growth of Bi nanoparticles.Two non-classical growth paths including single crystal growth and polycrystalline combined growth,as well as,corresponding layer-by-layer growth mechanism along{012}stable crystal plane of Bi nanoparticles with dodecahedron structure were revealed by in-situ TEM directly.These results provide important guidance and a new approach for in-depth understanding of the nucleation and growth kinetics of nanoparticles.展开更多
The electron cyclotron emission(ECE)diagnostic system has been developed on the ENN spherical torus(EXL-50).The ECE system is designed to detect radiation emitted by energetic electrons,rather than conventional 1D ele...The electron cyclotron emission(ECE)diagnostic system has been developed on the ENN spherical torus(EXL-50).The ECE system is designed to detect radiation emitted by energetic electrons,rather than conventional 1D electron temperature profile measurement,in the frequency range of 4-40 GHz.The system is composed of five subsystems,each covering a different frequency band,including the C-band(4-8 GHz),X-band(8-12 GHz),Ku-band(12-18 GHz),K-band(18-26.5 GHz)and Kα-band(26.4-40 GHz).The system uses heterodyne detection to analyze the received signals.The K-band and Kα-band subsystems are located horizontally in the equatorial plane of the EXL-50,while the C-band,X-band and Ku-band subsystems are located under the vacuum vessel of the EXL-50.To direct the microwaves from the plasma to the antennas for the horizontal detection subsystems,a quasi-optical system has been developed.For the vertical detection subsystems,the antennas are directly attached to the port located beneath the torus at R=700 mm,which is also the magnetic axis of the torus.The system integration,bench testing and initial experimental results will be thoroughly discussed,providing a comprehensive understanding of the ECE system s performance and capabilities.展开更多
Bioelectronic interventions,specifically trigeminal nerve st imulat ion(TNS),have attracted considerable attention in conditions where cortical spreading depolarizations(CSDs)accompanied by compromised cerebral perfus...Bioelectronic interventions,specifically trigeminal nerve st imulat ion(TNS),have attracted considerable attention in conditions where cortical spreading depolarizations(CSDs)accompanied by compromised cerebral perfusion may exacerbate neurological damage.While pharmacological interventions have demonstrated initial potential in addressing CSDs,a standardized treatment approach has not yet been established.The objective of this perspective is to explore emerging bioelectronic methodologies for addressing CSDs,particularly emphasizing TNS,and to underscore TNS’s capacity to enhance neurovascular coupling and cerebral perfusion.展开更多
Understanding the doping evolution from a Mott insulator to a superconductor probably holds the key to resolve the mystery of unconventional superconductivity in copper oxides. To elucidate the evolution of the electr...Understanding the doping evolution from a Mott insulator to a superconductor probably holds the key to resolve the mystery of unconventional superconductivity in copper oxides. To elucidate the evolution of the electronic state starting from the Mott insulator, we dose the surface of the parent phase Ca_(2)CuO_(2)Cl_(2) by depositing Rb atoms, which are supposed to donate electrons to the CuO_(2) planes underneath. We successfully achieved the Rb sub-monolayer thin films in forming the square lattice. The scanning tunneling microscopy or spectroscopy measurements on the surface show that the Fermi energy is pinned within the Mott gap but close to the edge of the charge transfer band. In addition, an in-gap state appears at the bottom of the upper Hubbard band(UHB), and the Mott gap will be significantly diminished. Combined with the Cl defect and the Rb adatom/cluster results, the electron doping is likely to increase the spectra weight of the UHB for the double occupancy. Our results provide information to understand the electron doping to the parent compound of cuprates.展开更多
Far-infrared(FIR)interferometer is widely used to measure the electron density in the magnetically confined fusion plasma devices.A new FIR laser interferometer with a total of 13 channels(8 horizontal channels and 5 ...Far-infrared(FIR)interferometer is widely used to measure the electron density in the magnetically confined fusion plasma devices.A new FIR laser interferometer with a total of 13 channels(8 horizontal channels and 5 oblique channels)is under development on the HL-3tokamak by using the formic-acid laser(HCOOH,f=694 GHz).In order to investigate the boundary electron density activity during the divertor discharge,three horizontal interferometry channels located at Z=-97,-76,76.5 cm have been successfully developed on HL-3 in 2023,and put into operation in recent experimental campaign,with a time resolution of<1.0μs and lineintegrated electron density resolution of~7.0×10^(16) m^(-2).This paper mainly focuses on the optical design of the three-channel interferometry system,as well as optical elements and recent experimental result on HL-3.展开更多
Cross-sections for electronic excitation and de-excitation among the ground state and lowest-lying seven electronic excited states of carbon monoxide(CO)by low-energy electron impact are computed using the R-matrix me...Cross-sections for electronic excitation and de-excitation among the ground state and lowest-lying seven electronic excited states of carbon monoxide(CO)by low-energy electron impact are computed using the R-matrix method.The excitation cross-sections from the ground state to the electronic states a^(3)Π,a'^(3)Σ^(+)+and A^(1)Πagree with previous experimental and theoretical results.In addition,the cross-sections for the I^(1)Σ^(+)-and D^(1)Δstates of CO,which will cascade to CO a'^(3)Σ^(+)+and A^(1)Πstates,are calculated.Furthermore,in contrast to the typical increase in electronic excitation cross-sections with collision energy,the de-excitation cross-sections show a negative trend with increasing energy.展开更多
Equating the Rest Mass Energy of a free electron to its Rest Charge Energy we prove that the electron cannot be a dimensionless point particle because if it were dimensionless, it would contain an infinite amount of R...Equating the Rest Mass Energy of a free electron to its Rest Charge Energy we prove that the electron cannot be a dimensionless point particle because if it were dimensionless, it would contain an infinite amount of Rest Charge Energy at the location of its charge since r = 0 gives , which is clearly not possible. Since the electron has no internal structure, equating its Rest Mass Energy to its Rest Charge Energy, we calculate the electron to be a sphere of radius 4.68 × 10<sup>-</sup><sup>16</sup> meters. We calculate the Electric Field at the surface of the electron due to its charge and the Repulsive Force two electrons in proximity exert on each other.展开更多
With the rapid development of portable electronics,new energy vehicles,and smart grids,ion batteries are becoming one of the most widely used energy storage devices,while the safety concern of ion batteries has always...With the rapid development of portable electronics,new energy vehicles,and smart grids,ion batteries are becoming one of the most widely used energy storage devices,while the safety concern of ion batteries has always been an urgent problem to be solved.To develop a safety-guaranteed battery,the characterization of the internal structure is indispensable,where electron microscopy plays a crucial role.Based on this,this paper summarizes the application of transmission electron microscopy(TEM)in battery safety,further concludes and analyzes the aspects of dendrite growth and solid electrolyte interface(SEI)formation that affect the safety of ion batteries,and emphasizes the importance of electron microscopy in battery safety research and the potential of these techniques to promote the future development of this field.These advanced electron microscopy techniques and their prospects are also discussed.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.42025404,42188101,42241143,41931073,and 42204160)the National Key R&D Program of China(Grant Nos.2022YFF0503700,2022YFF0503900,and 2021YFA0718600)+1 种基金the B-type Strategic Priority Program of the Chinese Academy of Sciences(Grant No.XDB41000000)the Fundamental Research Funds for the Central Universities(Grant Nos.2042022kf1012 and 2042022kf1016).
文摘We use the High-energy Electron Experiments(HEP)instrument onboard Arase(ERG)to conduct an energy-dependent cross-satellite calibration of electron fluxes measured by the High Energy Particle Detector(HEPD)onboard FengYun-4A(FY-4A)spanning from April 1,2017,to September 30,2019.By tracing the two-dimensional magnetic positions(L,magnetic local time[MLT])of FY-4A at each time,we compare the datasets of the conjugate electron fluxes over the range of 245–894 keV in 6 energy channels for the satellite pair within different sets of L×MLT.The variations in the electron fluxes observed by FY-4A generally agree with the Arase measurements,and the percentages of the ratios of electron flux conjunctions within a factor of 2 are larger than 50%.Compared with Arase,FY-4A systematically overestimates electron fluxes at all 6 energy channels,with the corresponding calibration factors ranging from 0.67 to 0.81.After the cross-satellite calibration,the electron flux conjunctions between FY-4A and Arase show better agreement,with much smaller normalized root mean square errors.Our results provide a valuable reference for the application of FY-4A high-energy electron datasets to in-depth investigations of the Earth’s radiation belt electron dynamics.
基金supported by the National Natural Science Foundation of China (Grant No. 60866001)the Special Assistant to High-Level Personnel Research Projects of Guizhou Provincial Party Committee Organization Department of China (Grant No. TZJF- 2008-31)+3 种基金the Support Plan of New Century Excellent Talents of Ministry of Education, China (Grant No. NCET-08-0651)the Doctorate Foundation of the State Education Ministry of China (Grant No. 20105201110003)the Special Governor Fund of Outstanding Professionals in Science and Technology and Education of Guizhou Province, China (Grant No. 2009114)the Doctoral Foundation Projects of Guizhou College of Finance and Economics in 2010
文摘Surface segregation is studied via the evolution of reflection high-energy electron diffraction (RHEED) patterns under different values of As4 BEP for InGaAs films. When the As4 BEP is set to be zero, the RHEED pattern keeps a 4x3/(nx3) structure with increasing temperature, and surface segregation takes place until 470 ℃ The RHEED pattern develops into a metal-rich (4x2) structure as temperature increases to 495℃. The reason for this is that surface segregation makes the In inside the InGaAs film climb to its surface. With the temperature increasing up to 515℃, the RHEED pattern turns into a GaAs(2x4) structure due to In desorption. While the As4 BEP comes up to a specific value (1.33 x 10-4 Pa-1.33 x 10-3 Pa), the surface temperature can delay the segregation and desorption. We find that As4 BEP has a big influence on surface desorption, while surface segregation is more strongly dependent on temperature than surface desorption.
文摘Various aspects of the influence of the quasi-real photons and the Coulomb resonances on the formation of the crosssection of inelastic scattering of high energy electrons on atomic nuclei are investigated. Emiss is the energy that disappears in the processes of knocking-on of protons in the reactions . A new hypothesis that interprets the origin of the energy losses is proposed. Specific experiments that can confirm or refute this hypothesis are proposed as well. The “regularized” cross-sections of electro-disintegration of nuclei by high-energy electrons are calculated in the framework of the nuclear shell model. It is shown that for the experimental verification of the existence of Coulomb resonances, it is necessary to investigate the processes at relatively small angles of scattering. The peculiarities of numerical methods that are crucial in the investigation of inelastic scattering of high-energy electrons on nuclei in the framework of the nuclear shell model are analyzed in this work as well. The cross-sections of the scattering of high-energy electrons on the angle are calculated. It is shown that the orthogonality of the wave functions of a knocked-on proton in the initial and final states plays an important role in the interpretation of this process.
基金Natural Science Foundation of Zhumadian City(058002)
文摘Using the model of the inverse Compton scattering between high-energy electrons and heat-radiation photons, the influence of heat-radiating photons on multi-photon Compton scattering high-energy electrons is studied . The results show that the energy loss, power loss, light resistance and light pressure of the high-energy electron formed by heat radiating are all proportional to the temperature T4 of the vacuum cavity of the electron,the Lorentz factor γ2 of the high-energy electrons, the scattering section of the electron and the number of photons acting at the same time with high-energy electrons. A good method for lessening the energy loss of the high-energy electron by using the one-photon Compton scattering between high-energy electrons and heat radiation photons is proposed.
文摘A gridded thermionic cathode electron gun was developed for the linear accelerator of the High Energy Photon Source(HEPS).An electron gun should provide a large maximum bunch charge with a wide adjustable range.To satisfy these requirements,the shape of the electrode was optimized using a multi-objective genetic algorithm.A large bunch charge with an adjustable range was achieved using the grid-limited gun,the flow of which was analyzed using 3-D simulations.The electron gun has been manufactured and tested,and the measured data of the grid-limited current and simulation results are compared and discussed in this study.
基金the National Natural Science Foundation of China(11875138,52077095).
文摘High-performance ion-conducting hydrogels(ICHs)are vital for developing flexible electronic devices.However,the robustness and ion-conducting behavior of ICHs deteriorate at extreme tempera-tures,hampering their use in soft electronics.To resolve these issues,a method involving freeze–thawing and ionizing radiation technology is reported herein for synthesizing a novel double-network(DN)ICH based on a poly(ionic liquid)/MXene/poly(vinyl alcohol)(PMP DN ICH)system.The well-designed ICH exhibits outstanding ionic conductivity(63.89 mS cm^(-1) at 25℃),excellent temperature resistance(-60–80℃),prolonged stability(30 d at ambient temperature),high oxidation resist-ance,remarkable antibacterial activity,decent mechanical performance,and adhesion.Additionally,the ICH performs effectively in a flexible wireless strain sensor,thermal sensor,all-solid-state supercapacitor,and single-electrode triboelectric nanogenerator,thereby highlighting its viability in constructing soft electronic devices.The highly integrated gel structure endows these flexible electronic devices with stable,reliable signal output performance.In particular,the all-solid-state supercapacitor containing the PMP DN ICH electrolyte exhibits a high areal specific capacitance of 253.38 mF cm^(-2)(current density,1 mA cm^(-2))and excellent environmental adaptability.This study paves the way for the design and fabrication of high-performance mul-tifunctional/flexible ICHs for wearable sensing,energy-storage,and energy-harvesting applications.
基金supported by the Taishan Scholar Program of Shandong Province,China (tsqn202211162)the National Natural Science Foundation of China (22102079)the Natural Science Foundation of Shandong Province of China (ZR2021YQ10,ZR2022QB163)。
文摘The poor stability of RuO_(2)electrocatalysts has been the primary obstacles for their practical application in polymer electrolyte membrane electrolyzers.To dramatically enhance the durability of RuO_(2)to construct activity-stability trade-off model is full of significance but challenging.Herein,a single atom Zn stabilized RuO_(2)with enriched oxygen vacancies(SA Zn-RuO_(2))is developed as a promising alternative to iridium oxide for acidic oxygen evolution reaction(OER).Compared with commercial RuO_(2),the enhanced Ru–O bond strength of SA Zn-RuO_(2)by forming Zn-O-Ru local structure motif is favorable to stabilize surface Ru,while the electrons transferred from Zn single atoms to adjacent Ru atoms protects the Ru active sites from overoxidation.Simultaneously,the optimized surrounding electronic structure of Ru sites in SA ZnRuO_(2)decreases the adsorption energies of OER intermediates to reduce the reaction barrier.As a result,the representative SA Zn-RuO_(2)exhibits a low overpotential of 210 mV to achieve 10 mA cm^(-2)and a greatly enhanced durability than commercial RuO_(2).This work provides a promising dual-engineering strategy by coupling single atom doping and vacancy for the tradeoff of high activity and catalytic stability toward acidic OER.
基金We acknowledge the support from the National Key Research and Development Program of China(Grant No.2022YFA1405000)the Natural Science Foundation of Jiangsu Province,Major Project(Grant No.BK20212004)+1 种基金the National Natural Science Foundation of China(Grant No.62374083)the State Key Laboratory of Analytical Chemistry for Life Science(Grant No.5431ZZXM2205).
文摘Stretchable electronics are crucial enablers for next-generation wearables intimately integrated into the human body.As the primary compliant conductors used in these devices,metallic nanostructure/elastomer composites often struggle to form conformal contact with the textured skin.Hybrid electrodes have been consequently developed based on conductive nanocomposite and soft hydrogels to establish seamless skin-device interfaces.However,chemical modifications are typically needed for reliable bonding,which can alter their original properties.To overcome this limitation,this study presents a facile fabrication approach for mechanically interlocked nanocomposite/hydrogel hybrid electrodes.In this physical process,soft microfoams are thermally laminated on silver nanowire nanocomposites as a porous interface,which forms an interpenetrating network with the hydrogel.The microfoam-enabled bonding strategy is generally compatible with various polymers.The resulting interlocked hybrids have a 28-fold improved interfacial toughness compared to directly stacked hybrids.These electrodes achieve firm attachment to the skin and low contact impedance using tissue-adhesive hydrogels.They have been successfully integrated into an epidermal sleeve to distinguish hand gestures by sensing mus-cle contractions.Interlocked nanocomposite/hydrogel hybrids reported here offer a promising platform to combine the benefits of both materials for epidermal devices and systems.
基金supported by China Agriculture Research System of MOF and MARA(CARS-41)Wens Fifth Five R&D Major Project(WENS-2020-1-ZDZX-007)。
文摘The sensory perception of food is a dynamic process,which is closely related to the release of flavor substances during oral processing.It’s not only affected by the food material,but also subjected to the individual oral environment.To explore the oral processing characteristics of soft-boiled chicken,the sensory properties,texture,particle size,viscosity,characteristic values of electronic nose and tongue of different chicken samples were investigated.The correlation analysis showed that the physical characteristics especially the cohesiveness,springiness,resilience of the sample determined oral processing behavior.The addition of chicken skin played a role in lubrication during oral processing.The particle size of the bolus was heightened at the early stage,and the fluidity was enhanced in the end,which reduced the chewing time to the swallowing point and raised the aromatic compounds signal of electronic nose.But the effect of chicken skin on chicken thigh with relatively high fat content,was opposite in electronic nose,which had a certain masking effect on the perception of umami and sweet taste.In conclusion,fat played a critical role in chicken oral processing and chicken thigh had obvious advantages in comprehensive evaluation of soft-boiled chicken,which was more popular among people.
基金Project supported by the National Natural Science Foundation of China (Grant Nos.11975062 and 11605021)the Fundamental Research Funds for the Central Universities (Grant No.3132023192)。
文摘The existence of a significant electron drift instability(EDI) in the Hall thruster is considered as one of the possible causes of the abnormal increase in axial electron mobility near the outlet of the channel. In recent years, extensive simulation research on the characteristics of EDI has been conducted, but the excitation mechanism and growth mechanism of EDI in linear stage and nonlinear stage remain unclear. In this work, a one-dimensional PIC model in the azimuthal direction of the thruster near-exit region is established to gain further insights into the mechanism of the EDI in detail, and the effects of different types of propellants on EDI characteristics are discussed. The changes in axial electron transport caused by EDI under different types of propellants and electromagnetic field strengths are also examined. The results indicate that EDI undergoes a short linear growth phase before transitioning to the nonlinear phase and finally reaching saturation through the ion Landau damping. The EDI drives a significant ion heating in the azimuthal direction through electron–ion friction before entering the quasi-steady state, which increases the axial mobility of the electrons. Using lighter atomic weight propellant can effectively suppress the oscillation amplitude of EDI, but it will increase the linear growth rate, frequency, and phase velocity of EDI. Compared with the classical mobility, the axial electron mobility under the EDI increases by three orders of magnitude, which is consistent with experimental phenomena. The change of propellant type is insufficient to significantly change the axial electron mobility. It is also found that the collisions between electrons and neutral gasescan significantly affect the axial electron mobility under the influence of EDI, and lead the strength of the electric field to increase and the strength of the magnetic field to decrease, thereby both effectively suppressing the axial transport of electrons.
基金the NSF CCSS-2152638 and the IEN Center Grant from the Institute for Electronics and Nanotechnology at Georgia Tech.
文摘This review summarizes recent progress in developing wireless,batteryless,fully implantable biomedical devices for real-time continuous physiological signal monitoring,focusing on advancing human health care.Design considerations,such as biological constraints,energy sourcing,and wireless communication,are discussed in achieving the desired performance of the devices and enhanced interface with human tissues.In addition,we review the recent achievements in materials used for developing implantable systems,emphasizing their importance in achieving multi-functionalities,biocompatibility,and hemocompatibility.The wireless,batteryless devices offer minimally invasive device insertion to the body,enabling portable health monitoring and advanced disease diagnosis.Lastly,we summarize the most recent practical applications of advanced implantable devices for human health care,highlighting their potential for immediate commercialization and clinical uses.
基金supported by the National Key Research and Development Program of China(2021YFB4000602)the National Natural Science Foundation of China(21988101,22279130,21633011)+1 种基金the Dalian Science and Technology Innovation Fund(2023RJ016)the Liaoning Revitalization Talents Program(x LYC2002076)。
文摘Hydride ion(H-)conductors have drawn much attention due to their potential applications in hydrideion-based devices.Rare earth metal hydrides(REH_(x))have fast H-conduction which,unfortunately,is accompanied by detrimental electron conduction preventing their application as ion conductors.Here,REH_(x)(RE=Nd,Ce,and Pr)with varied grain sizes,rich grain boundaries,and defects have been prepared by ball milling and subsequent sintering.The electronic conductivity of the ball-milled REH_(x)samples can be reduced by 2-4 orders of magnitude compared with the non-ball-milled samples.The relationship of electron conduction and miscrostructures in REH_(x)is studied and discussed based on experimental data and previously-proposed classical and quantum theories.The H-conductivity of all REH_(x)is about 10^(-4)to 10^(-3)S cm^(-1)at room temperature,showing promise for the development of H-conductors and their applications in clean energy storage and conversion.
基金Funded by the National Natural Science Foundation of China(No.52103285)the 111 National Project(No.B20002)。
文摘The nucleation and growth mechanism of nanoparticles is an important theory,which can guide the preparation of nanomaterials.However,it is still lacking in direct observation on the details of the evolution of intermediate state structure during nucleation and growth.In this work,the evolution process of bismuth nanoparticles induced by electron beam was revealed by in-situ transmission electron microscopy(TEM)at atomic scale.The experimental results demonstrate that the size,stable surface and crystallographic defect have important influences on the growth of Bi nanoparticles.Two non-classical growth paths including single crystal growth and polycrystalline combined growth,as well as,corresponding layer-by-layer growth mechanism along{012}stable crystal plane of Bi nanoparticles with dodecahedron structure were revealed by in-situ TEM directly.These results provide important guidance and a new approach for in-depth understanding of the nucleation and growth kinetics of nanoparticles.
基金performed under the auspices of National Natural Science Foundation of China(No.11605244)supported by the High-End Talents Program of Hebei Province,Innovative Approaches towards Development of CarbonFree Clean Fusion Energy(No.2021HBQZYCSB006)。
文摘The electron cyclotron emission(ECE)diagnostic system has been developed on the ENN spherical torus(EXL-50).The ECE system is designed to detect radiation emitted by energetic electrons,rather than conventional 1D electron temperature profile measurement,in the frequency range of 4-40 GHz.The system is composed of five subsystems,each covering a different frequency band,including the C-band(4-8 GHz),X-band(8-12 GHz),Ku-band(12-18 GHz),K-band(18-26.5 GHz)and Kα-band(26.4-40 GHz).The system uses heterodyne detection to analyze the received signals.The K-band and Kα-band subsystems are located horizontally in the equatorial plane of the EXL-50,while the C-band,X-band and Ku-band subsystems are located under the vacuum vessel of the EXL-50.To direct the microwaves from the plasma to the antennas for the horizontal detection subsystems,a quasi-optical system has been developed.For the vertical detection subsystems,the antennas are directly attached to the port located beneath the torus at R=700 mm,which is also the magnetic axis of the torus.The system integration,bench testing and initial experimental results will be thoroughly discussed,providing a comprehensive understanding of the ECE system s performance and capabilities.
基金supported by National Institute of Neurological Disorders and Stroke of the National Institutes of Health under award number R21NS114763US Army Medical Research and Materiel Command (USAMRMC) under award#W81XWH-18-1-0773merit-based career enhancement award at the Feinstein Institutes for Medical Research (to CL)
文摘Bioelectronic interventions,specifically trigeminal nerve st imulat ion(TNS),have attracted considerable attention in conditions where cortical spreading depolarizations(CSDs)accompanied by compromised cerebral perfusion may exacerbate neurological damage.While pharmacological interventions have demonstrated initial potential in addressing CSDs,a standardized treatment approach has not yet been established.The objective of this perspective is to explore emerging bioelectronic methodologies for addressing CSDs,particularly emphasizing TNS,and to underscore TNS’s capacity to enhance neurovascular coupling and cerebral perfusion.
基金supported by the National Natural Science Foundation of China (Grant Nos. 11974171, 12061131001, and 11927809)the National Key R&D Program of China (Grant No. 2022YFA1403201)。
文摘Understanding the doping evolution from a Mott insulator to a superconductor probably holds the key to resolve the mystery of unconventional superconductivity in copper oxides. To elucidate the evolution of the electronic state starting from the Mott insulator, we dose the surface of the parent phase Ca_(2)CuO_(2)Cl_(2) by depositing Rb atoms, which are supposed to donate electrons to the CuO_(2) planes underneath. We successfully achieved the Rb sub-monolayer thin films in forming the square lattice. The scanning tunneling microscopy or spectroscopy measurements on the surface show that the Fermi energy is pinned within the Mott gap but close to the edge of the charge transfer band. In addition, an in-gap state appears at the bottom of the upper Hubbard band(UHB), and the Mott gap will be significantly diminished. Combined with the Cl defect and the Rb adatom/cluster results, the electron doping is likely to increase the spectra weight of the UHB for the double occupancy. Our results provide information to understand the electron doping to the parent compound of cuprates.
基金supported by the National Magnetic Confinement Fusion Science Program of China(Nos.2019YFE03020004,2018YFE0304102 and 2019YFE03020002)the Department of Science and Technology of Sichuan Province(No.2020YJ0463)。
文摘Far-infrared(FIR)interferometer is widely used to measure the electron density in the magnetically confined fusion plasma devices.A new FIR laser interferometer with a total of 13 channels(8 horizontal channels and 5 oblique channels)is under development on the HL-3tokamak by using the formic-acid laser(HCOOH,f=694 GHz).In order to investigate the boundary electron density activity during the divertor discharge,three horizontal interferometry channels located at Z=-97,-76,76.5 cm have been successfully developed on HL-3 in 2023,and put into operation in recent experimental campaign,with a time resolution of<1.0μs and lineintegrated electron density resolution of~7.0×10^(16) m^(-2).This paper mainly focuses on the optical design of the three-channel interferometry system,as well as optical elements and recent experimental result on HL-3.
基金Project supported by the National Natural Science Foundation of China (Grant No.11974253)。
文摘Cross-sections for electronic excitation and de-excitation among the ground state and lowest-lying seven electronic excited states of carbon monoxide(CO)by low-energy electron impact are computed using the R-matrix method.The excitation cross-sections from the ground state to the electronic states a^(3)Π,a'^(3)Σ^(+)+and A^(1)Πagree with previous experimental and theoretical results.In addition,the cross-sections for the I^(1)Σ^(+)-and D^(1)Δstates of CO,which will cascade to CO a'^(3)Σ^(+)+and A^(1)Πstates,are calculated.Furthermore,in contrast to the typical increase in electronic excitation cross-sections with collision energy,the de-excitation cross-sections show a negative trend with increasing energy.
文摘Equating the Rest Mass Energy of a free electron to its Rest Charge Energy we prove that the electron cannot be a dimensionless point particle because if it were dimensionless, it would contain an infinite amount of Rest Charge Energy at the location of its charge since r = 0 gives , which is clearly not possible. Since the electron has no internal structure, equating its Rest Mass Energy to its Rest Charge Energy, we calculate the electron to be a sphere of radius 4.68 × 10<sup>-</sup><sup>16</sup> meters. We calculate the Electric Field at the surface of the electron due to its charge and the Repulsive Force two electrons in proximity exert on each other.
基金supported by the National Natural Science Foundation of China(No.22209027)the Shenzhen Science and Technology Program(No.JCYJ20220530142806015 and No.JCYJ20220818101008018)+1 种基金the Shenzhen“Pengcheng Peacock Program’the Tsinghua SIGS Cross-disciplinary Research and Innovation Fund(No.JC2022002)。
文摘With the rapid development of portable electronics,new energy vehicles,and smart grids,ion batteries are becoming one of the most widely used energy storage devices,while the safety concern of ion batteries has always been an urgent problem to be solved.To develop a safety-guaranteed battery,the characterization of the internal structure is indispensable,where electron microscopy plays a crucial role.Based on this,this paper summarizes the application of transmission electron microscopy(TEM)in battery safety,further concludes and analyzes the aspects of dendrite growth and solid electrolyte interface(SEI)formation that affect the safety of ion batteries,and emphasizes the importance of electron microscopy in battery safety research and the potential of these techniques to promote the future development of this field.These advanced electron microscopy techniques and their prospects are also discussed.