Achieving a highly robust zinc(Zn)metal anode is extremely important for improving the performance of aqueous Zn-ion batteries(AZIBs)for advancing“carbon neutrality”society,which is hampered by the uncontrollable gr...Achieving a highly robust zinc(Zn)metal anode is extremely important for improving the performance of aqueous Zn-ion batteries(AZIBs)for advancing“carbon neutrality”society,which is hampered by the uncontrollable growth of Zn dendrite and severe side reactions including hydrogen evolution reaction,corrosion,and passivation,etc.Herein,an interlayer containing fluorinated zincophilic covalent organic framework with sulfonic acid groups(COF-S-F)is developed on Zn metal(Zn@COF-S-F)as the artificial solid electrolyte interface(SEI).Sulfonic acid group(-SO_(3)H)in COF-S-F can effectively ameliorate the desolvation process of hydrated Zn ions,and the three-dimensional channel with fluoride group(-F)can provide interconnected channels for the favorable transport of Zn ions with ion-confinement effects,endowing Zn@COF-S-F with dendrite-free morphology and suppressed side reactions.Consequently,Zn@COF-S-F symmetric cell can stably cycle for 1,000 h with low average hysteresis voltage(50.5 m V)at the current density of 1.5 m A cm^(-2).Zn@COF-S-F|Mn O_(2)cell delivers the discharge specific capacity of 206.8 m Ah g^(-1)at the current density of 1.2 A g^(-1)after 800 cycles with high-capacity retention(87.9%).Enlightening,building artificial SEI on metallic Zn surface with targeted design has been proved as the effective strategy to foster the practical application of high-performance AZIBs.展开更多
Composite Li metal anodes based on three-dimensional(3D) porous frameworks have been considered as an effective material for achieving stable Li metal batteries with high energy density.However,uneven Li deposition be...Composite Li metal anodes based on three-dimensional(3D) porous frameworks have been considered as an effective material for achieving stable Li metal batteries with high energy density.However,uneven Li deposition behavior still occurs at the top of 3D frameworks owing to the local accumulation of Li ions.To promote uniform Li deposition without top dendrite growth,herein,a layered multifunctional framework based on oxidation-treated polyacrylonitrile(OPAN) and metal-organic framework(MOF) derivatives was proposed for rationally regulating the distribution of Li ions flux,nucleation sites,and electrical conductivity.Profiting from these merits,the OPAN/carbon nano fiber-MOF(CMOF) composite framework demonstrated a reversible Li plating/stripping behavior for 500 cycles with a stable Coulombic efficiency of around 99.0% at the current density of 2 mA/cm~2.Besides,such a Li composite anode exhibited a superior cycle lifespan of over 1300 h under a low polarized voltage of 18 mV in symmetrical cells.When the Li composite anode was paired with LiFePO_(4)(LFP) cathode,the obtained full cell exhibited a stable cycling over 500 cycles.Moreover,the COMSOL Multiphysics simulation was conducted to reveal the effects on homogeneous Li ions distribution derived from the above-mentioned OPAN/CMOF framework and electrical insulation/conduction design.These electrochemical and simulated results shed light on the difficulties of designing stable and safe Li metal anode via optimizing the 3D frameworks.展开更多
Heavy-ion flux is an important experimental parameter in the ground based single event tests. The flux impact on a single event effect in different memory devices is analyzed by using GEANT4 and TCAD simulation method...Heavy-ion flux is an important experimental parameter in the ground based single event tests. The flux impact on a single event effect in different memory devices is analyzed by using GEANT4 and TCAD simulation methods. The transient radial track profile depends not only on the linear energy transfer （LET） of the incident ion, but also on the mass and energy of the ion. For the ions with the energies at the Bragg peaks, the radial charge distribution is wider when the ion LET is larger. The results extracted from the GEANT4 and TCAD simulations, together with detailed analysis of the device structure, are presented to demonstrate phenomena observed in the flux related experiment. The analysis shows that the flux effect conclusions drawn from the experiment are intrinsically connected and all indicate the mechanism that the flux effect stems from multiple ion-induced pulses functioning together and relies exquisitely on the specific response of the device.展开更多
A high-flux linear plasma device in Sichuan University plasma-surface interaction（SCU-PSI）based on a cascaded arc source has been established to simulate the interactions between helium and hydrogen plasma with the ...A high-flux linear plasma device in Sichuan University plasma-surface interaction（SCU-PSI）based on a cascaded arc source has been established to simulate the interactions between helium and hydrogen plasma with the plasma-facing components in fusion reactors.In this paper,the helium plasma has been characterized by a double-pin Langmuir probe.The results show that the stable helium plasma beam with a diameter of 26 mm was constrained very well at a magnetic field strength of 0.3 T.The core density and ion flux of helium plasma have a strong dependence on the applied current,magnetic field strength and gas flow rate.It could reach an electron density of1.2×10^19m^-3and helium ion flux of 3.2×10^22m^-2s^-1,with a gas flow rate of 4 standard liter per minute,magnetic field strength of 0.2 T and input power of 11 k W.With the addition of-80 Vapplied to the target to increase the helium ion energy and the exposure time of 2 h,the flat top temperature reached about 530°C.The different sizes of nanostructured fuzz on irradiated tungsten and molybdenum samples surfaces under the bombardment of helium ions were observed by scanning electron microscopy.These results measured in the SCU-PSI linear device provide a reference for International Thermonuclear Experimental Reactor related PSI research.展开更多
One of the earliest events leading to cell activation and growth is the hydrolysis of inositol phospholipids producing various membrane signals induced by an interaction between growth factors or hormones with their r...One of the earliest events leading to cell activation and growth is the hydrolysis of inositol phospholipids producing various membrane signals induced by an interaction between growth factors or hormones with their respective receptors on the cell membrane [1]. To demonstrate the mitogenio action of transferrin, our results show that an addition of transferrin to 'serum-deprived' rat hepatoma cells produced a rapid but transient rise in inositol 1, 4, 5-trisphosphate (IP3) level, and at the same time, an increased intraoellular Oa2+ activity and a oytoplasmic alkalinization were observed. These signal transduo-tions further lend support to the mitogenic nature of transferrin. In addition, a possible link between the receptor-mediated endocytosis of transferrin with the generation of intraoellular signals is discussed herewith.展开更多
The significant role of ion beam flux during nitriding 304 austenitic stainless steel has been investigated by using a radio frequency inductively-coupled plasma reactor into which a sample with negative bias voltage ...The significant role of ion beam flux during nitriding 304 austenitic stainless steel has been investigated by using a radio frequency inductively-coupled plasma reactor into which a sample with negative bias voltage was inserted. A milliammeter is used to detect tile current of ions which collide with the sample and optical emission spectroscopy is used to discern the reactive species included in the nitrogen plasma. The nitriding efficiency is indicated by X-ray diffraction and the microhardness test. The reported data reveal that the ion beam flux density as well as the deposition pressure, bias voltage and time can strongly affect the nitriding of stainless steel via tile expanded multiphase microstructure inside the nitrided layer. The increase in the density of ion flux results in an ascent in the intensity of the expanded peak and a simultaneous decline in the intensity of the 3＇ austenite peak. The evolution trend of ion beam flux density is described as a function of tile operating pressure and the bias voltage. The maxinmm ion flux density has been achieved at 10 Pa pressure and 500 V bias voltage. A reasonable nitriding region has been, consequently, suggested after comparing this work with previously reported results.展开更多
In this work, study of laser-induced ions is presented. The plasma was produced by focusing a Nd：YAG laser, with a wavelength of 1064 nm, a pulsed width of 9-14 ns, a power of 1.1 MW and energy of 10 mJ, on silver ta...In this work, study of laser-induced ions is presented. The plasma was produced by focusing a Nd：YAG laser, with a wavelength of 1064 nm, a pulsed width of 9-14 ns, a power of 1.1 MW and energy of 10 mJ, on silver target in vacuum （10-3 Torr= 1.3332 Pa）. The characteristics of ion streams were investigated by CR-39 detectors located at angles of 0°, 30°, 60° and 90° with respect to normal of the target. The distance between the silver target and each detector was 11 cm. The energy of silver ions was found ranging from 1.5 eV to 1.06E4 eV. There was a high concentration of ions with low energy as compared to those with high energy, showing the energy distribution amongst the ions. The flux of ions was maximum in the axial direction which was decreasing with the angle increase with respect to normal of the target, and finally became minimum in the radial direction. Hence the silver ions have shown anisotropic behaviour.展开更多
During geomagnetically active times such as geomagnetic storms,large amounts of energy can be released into the Earth’s magnetosphere and change the ring current intensity.Previous studies showed that significant enh...During geomagnetically active times such as geomagnetic storms,large amounts of energy can be released into the Earth’s magnetosphere and change the ring current intensity.Previous studies showed that significant enhancement of the ring current was related to geomagnetic storms,while few studies have examined substorm effects on ring current dynamics.In this study,we examine the ring current variation during non-storm time(SYM-H>−50 nT)substorms,especially during super-substorms(AE>1000 nT).We perform a statistical analysis of ring current plasma pressure and number flux of various ion species under different substorm conditions,based on Van Allen Probe observations.The plasma pressure and ion fluxes of the ring current increased dramatically during supersubstorms,while little change was observed for substorms with AE<1000 nT.The results shown in this study indicate that a non-storm time super-substorm may also have a significant contribution to the ring current.展开更多
To understand the characteristics of the plasma sheath within small tubes,a 2D numerical model of He discharge within dielectric tubes is developed.During plasma propagation for a tube diameter of 0.05 mm,the sheath t...To understand the characteristics of the plasma sheath within small tubes,a 2D numerical model of He discharge within dielectric tubes is developed.During plasma propagation for a tube diameter of 0.05 mm,the sheath thickness in the plasma head is almost equal to the tube radius.It decreases rapidly to several micrometers at an axial distance of 0.05 mm behind the plasma head,and then slightly increases and saturates at the axial position far behind the plasma head.A plasma-gas sheath surrounding the central plasma column is observed for a tube diameter equal to or greater than 0.8 mm.It is replaced by a plasma-wall sheath for smaller tubes.With the decrease in the tube diameter,the sheath thickness far behind the plasma head decreases while the ion flux increases significantly.However,when O_(2)gas with a proportion of 2%is added,both the sheath thickness and ion flux decrease.展开更多
A new compact cascaded arc device for plasma-wall interaction study is developed at the Institute of Plasma Physics,Chinese Academy of Sciences.A magnetic field up to 0.8 T is achieved to confine plasmas in a 1.2 m lo...A new compact cascaded arc device for plasma-wall interaction study is developed at the Institute of Plasma Physics,Chinese Academy of Sciences.A magnetic field up to 0.8 T is achieved to confine plasmas in a 1.2 m long and 0.1 m diameter vacuum chamber.Gas fluid type analysis in this compact vacuum system was done under high particle flux condition.The gas pressure obtained by calculation was consistent with the measurement result.Continuous argon plasma discharge with ion flux of~0.5×10^(24)m^(-2)s^(-1)is successfully sustained for more than 1h.The effects of magnetic field configuration,gas flow rate,and discharge arc current on the ion flux to target were studied in detail.展开更多
Maintenance of ion homeostasis,particularly the regulation of K^(+)and Na^(+)uptake,is important for all plants to adapt to salinity.Observations on ionic response to salinity and net fluxes of K^(+),Na^(+)in the root...Maintenance of ion homeostasis,particularly the regulation of K^(+)and Na^(+)uptake,is important for all plants to adapt to salinity.Observations on ionic response to salinity and net fluxes of K^(+),Na^(+)in the root exhibited by plants during salt stress have highlighted the need for further investigation.The objectives of this study were to compare salt adaptation of two Chinese Iris(Iris lactea Pall.var.chinensis(Fisch.)Koidz.)populations,and to improve understanding of adaptation to salinity exhibited by plants.Plants used in this study were grown from seeds collected in the Xinjiang Uygur Autonomous Region(Xj)and Beijing Municipality(Bj),China.Hydroponicallygrown seedlings of the two populations were supplied with nutrient solutions containing 0.1(control)and 140 mmol·L^(–1) NaCl.After 12 days,plants were harvested for determination of relative growth rate and K^(+),Na^(+)concentrations.Net fluxes of K^(+),Na^(+)from the apex and along the root axis to 10.8 mm were measured using noninvasive micro-test technique.With 140 mmol·L^(–1) NaCl treatment,shoots for population Xj had larger relative growth rate and higher K^(+)concentration than shoots for population Bj.However,the Na^(+)concentrations in both shoots and roots were lower for Xj than those for Bj.There was a lower net efflux of K^(+)found in population Xj than by Bj in the mature zone(approximately 2.4^(–1)0.8 mm from root tip).However,no difference in the efflux of Na^(+)between the populations was obtained.Population Xj of I.lactea continued to grow normally under NaCl stress,and maintained a higher K^(+)/Na^(+)ratio in the shoots.These traits,which were associated with lower K^(+)leakage,help population Xj adapt to saline environments.展开更多
Plant salinity tolerance is a physiologically complex trait, with numerous mechanisms contributing to it. In this work, we show that the ability of leaf mesophyll to retain K＋ represents an important and essentially ...Plant salinity tolerance is a physiologically complex trait, with numerous mechanisms contributing to it. In this work, we show that the ability of leaf mesophyll to retain K＋ represents an important and essentially overlooked component of a salinity tolerance mechanism. The strong positive correlation between mesophyll K＋ retention ability under saline conditions （quantified by the magnitude of NaCl-induced K＋ efflux from mesophyll） and the overall salinity tolerance （relative fresh weight and/or survival or damage under salinity stress） was found while screening 46 barley （Hordeum vulgare L.） genotypes contrasting in their salinity tolerance. Genotypes with intrinsically higher leaf K＋ content under control conditions were found to possess better K＋ retention ability under salinity and, hence, overall higher tolerance. Contrary to previous reports for barley roots, K＋ retention in mesophyll was not associated with an increased H＋-pumping in tolerant varieties but instead correlated negatively with this trait. These findings are explained by the fact that increased H＋ extrusion may be needed to charge balance the activity and provide the driving force for the high affinity HAK/KUP K＋ transporters required to restore cytosolic K＋ homeostasis in salt-sensitive genotypes.展开更多
Li metal has been regarded as the holy grail for the next-generation Li-ion battery.Li dendrites issues,however,impede its practical application.In general,prolonging the sand time of Li nucleation and regulating homo...Li metal has been regarded as the holy grail for the next-generation Li-ion battery.Li dendrites issues,however,impede its practical application.In general,prolonging the sand time of Li nucleation and regulating homogeneous Li^(+) flux are effective approaches to suppress the dendrites formation and growth.Regarding this view,a functional polypropylene (PP) separator is developed to regulate ion transportation via a newly designed Li-based metal-organic framework (Li-MOF) coating.The Li-MOF crystallizes in the orthorhombic space group P212121 and features a double-walled three-dimensional (3D) structure with 1D channels.The well-defined intrinsic nanochannels of Li-MOF and the steric-hinerance effect both restrict free migration of anions,contributing to a high Li^(+) transference number of 0.65,which improve the Sand time of Li nucleation.Meanwhile,the Li-MOF coating with uniform porous structure promotes homogeneous Li^(+) flux at the surface of Li metal.Furthermore,the Li-MOF coating layer helps to build solid-electrolyte interphase (SEI) layer that comprises of inorganic Li F and Li_(3)N,which further prohibits the dendrites growth.Consequently,a highly stable Li plating/stripping cycling for over 1000 h is achieved.The functional separator also enables high-performance full lithium metal cells,the high-rate and long-stable cycling performance of Li Ni_(0.8)Mn_(0.1)Co_(0.1)(NMC811)-Li and Li Co O_(2)(LCO)-Li cells further demonstrate the feasibility of this concept.展开更多
Based on the comparison with the Earth, using the LB magnetic field model, the distribution of O+ ion originating from the ionosphere in the Martian magnetosphere is theoretically studied under different conditions of...Based on the comparison with the Earth, using the LB magnetic field model, the distribution of O+ ion originating from the ionosphere in the Martian magnetosphere is theoretically studied under different conditions of the tail-like magnetic field. The results show that the tail-like magnetic field has influence on the O+ ion flux in the Martian magnetotail: (i) the O+ ion flux in the Martian tail will increase if the tail-like magnetic field increases; when the tail-like magnetic field increases from 5 nT to 20 nT, the O+ ion flux increases 3 times in the region of 2.8R m in the Martian tail; and (ii) the O+ ion flux decreases with increasing intrinsic moment; when the intrinsic moment increases about 5 times, the flux decreases to one fourth in the region of 2.8R m in the Martian tail. According to the data on the O+ ion flux and theoretical result in this paper, the deduced Martian intrinsic moment is about 2 ×1021 Gcm3. This is consistent with the most recent observation by the USA satellite MGS.展开更多
Species of wild rice(Oryza spp.)possess a wide range of stress tolerance traits that can be potentially utilized in breeding climate-resilient cultivated rice cultivars(Oryza sativa)thereby aiding global food security...Species of wild rice(Oryza spp.)possess a wide range of stress tolerance traits that can be potentially utilized in breeding climate-resilient cultivated rice cultivars(Oryza sativa)thereby aiding global food security.In this study,we conducted a greenhouse trial to evaluate the salinity tolerance of six wild rice species,one cultivated rice cultivar(IR64)and one landrace(Pokkali)using a range of electrophysiological,imaging,and whole-plant physiological techniques.Three wild species(O.latifolia,O.officinalis and O.coarctata)were found to possess superior salinity stress tolerance.The underlying mechanisms,however,were strikingly different.Na+accumulation in leaves of O.latifolia,O.officinalis and O.coarctata were significantly higher than the tolerant landrace,Pokkali.Na+accumulation in mesophyll cells was only observed in O.coarctata,suggesting that O.officinalis and O.latifolia avoid Na+accumulation in mesophyll by allocating Na+to other parts of the leaf.The finding also suggests that O.coarctata might be able to employ Na+as osmolyte without affecting its growth.Further study of Na+allocation in leaves will be helpful to understand the mechanisms of Na+accumulation in these species.In addition,O.coarctata showed Proto Kranz-like leaf anatomy(enlarged bundle sheath cells and lower numbers of mesophyll cells),and higher expression of C4-related genes(e.g.,NADPME,PPDK)and was a clear outlier with respect to salinity tolerance among the studied wild and cultivated Oryza species.The unique phylogenetic relationship of O.coarctata with C4 grasses suggests the potential of this species for breeding rice with high photosynthetic rate under salinity stress in the future.展开更多
The influence of fluorine on the structure of CaO Si（）e-Al2Oa Na2O-CaF2 continuous-casting-type slag was measured by Raman spectroscopy, and the degree of polymerization of mould flux and the structural behavior of ...The influence of fluorine on the structure of CaO Si（）e-Al2Oa Na2O-CaF2 continuous-casting-type slag was measured by Raman spectroscopy, and the degree of polymerization of mould flux and the structural behavior of F- in the melt were investigated by classifying and quantifying the structural species of F ions. The results exhibit that the main structural units of Si O tetrahedra are Q1, Q1 and Q2, and the actual measured number of non bridging oxygen ions in the [SiO4 ]-tetrahedra （denoted by NBO/T） in creases from 2. 73 to 3.44 with increasing the molar ratio of F to （F＋O） （denoted by XF/X（F-O ） from 0.06 to 0. 19. It means that the degree of polymerization o1 meh structure decreases with an increase in XE/X（F＋O）. In addition, most of F- ions were distributed in Si-O tetrahedra and Al-O tetrahedra. With increasing XF/X（F＋O）, the complex structural units Al-Otetrahedra are gradually replaced hy discrete structural units A1F4 because of the breakage of Al-O bonds in Al-Otetrahedra by F ions, and the SiO （bridging oxygen） bonds of SiO tetrahedra are broken to form [SiOnF1-n]-tetrahedra by F ions coordinating with Si4 ＋ .展开更多
基金financially supported by National Natural Science Foundation of China(Nos.51872090,51772097,52372252)Hebei Natural Science Fund for Distinguished Young Scholar(No.E2019209433)+1 种基金Youth Talent Program of Hebei Provincial Education Department(No.BJ2018020)Natural Science Foundation of Hebei Province(No.E2020209151)。
文摘Achieving a highly robust zinc(Zn)metal anode is extremely important for improving the performance of aqueous Zn-ion batteries(AZIBs)for advancing“carbon neutrality”society,which is hampered by the uncontrollable growth of Zn dendrite and severe side reactions including hydrogen evolution reaction,corrosion,and passivation,etc.Herein,an interlayer containing fluorinated zincophilic covalent organic framework with sulfonic acid groups(COF-S-F)is developed on Zn metal(Zn@COF-S-F)as the artificial solid electrolyte interface(SEI).Sulfonic acid group(-SO_(3)H)in COF-S-F can effectively ameliorate the desolvation process of hydrated Zn ions,and the three-dimensional channel with fluoride group(-F)can provide interconnected channels for the favorable transport of Zn ions with ion-confinement effects,endowing Zn@COF-S-F with dendrite-free morphology and suppressed side reactions.Consequently,Zn@COF-S-F symmetric cell can stably cycle for 1,000 h with low average hysteresis voltage(50.5 m V)at the current density of 1.5 m A cm^(-2).Zn@COF-S-F|Mn O_(2)cell delivers the discharge specific capacity of 206.8 m Ah g^(-1)at the current density of 1.2 A g^(-1)after 800 cycles with high-capacity retention(87.9%).Enlightening,building artificial SEI on metallic Zn surface with targeted design has been proved as the effective strategy to foster the practical application of high-performance AZIBs.
基金supported by the National Natural Science Foundation of China (52302292, 52302058, 52302085)the China Postdoctoral Science Foundation (2021M702225)+1 种基金the Anhui Province University Natural Science Research Project (2023AH030093, 2023AH040301)the Startup Research Fund of Chaohu University (KYQD-2023005, KYQD-2023051)。
文摘Composite Li metal anodes based on three-dimensional(3D) porous frameworks have been considered as an effective material for achieving stable Li metal batteries with high energy density.However,uneven Li deposition behavior still occurs at the top of 3D frameworks owing to the local accumulation of Li ions.To promote uniform Li deposition without top dendrite growth,herein,a layered multifunctional framework based on oxidation-treated polyacrylonitrile(OPAN) and metal-organic framework(MOF) derivatives was proposed for rationally regulating the distribution of Li ions flux,nucleation sites,and electrical conductivity.Profiting from these merits,the OPAN/carbon nano fiber-MOF(CMOF) composite framework demonstrated a reversible Li plating/stripping behavior for 500 cycles with a stable Coulombic efficiency of around 99.0% at the current density of 2 mA/cm~2.Besides,such a Li composite anode exhibited a superior cycle lifespan of over 1300 h under a low polarized voltage of 18 mV in symmetrical cells.When the Li composite anode was paired with LiFePO_(4)(LFP) cathode,the obtained full cell exhibited a stable cycling over 500 cycles.Moreover,the COMSOL Multiphysics simulation was conducted to reveal the effects on homogeneous Li ions distribution derived from the above-mentioned OPAN/CMOF framework and electrical insulation/conduction design.These electrochemical and simulated results shed light on the difficulties of designing stable and safe Li metal anode via optimizing the 3D frameworks.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.U1532261,11690041,and 11675233)
文摘Heavy-ion flux is an important experimental parameter in the ground based single event tests. The flux impact on a single event effect in different memory devices is analyzed by using GEANT4 and TCAD simulation methods. The transient radial track profile depends not only on the linear energy transfer （LET） of the incident ion, but also on the mass and energy of the ion. For the ions with the energies at the Bragg peaks, the radial charge distribution is wider when the ion LET is larger. The results extracted from the GEANT4 and TCAD simulations, together with detailed analysis of the device structure, are presented to demonstrate phenomena observed in the flux related experiment. The analysis shows that the flux effect conclusions drawn from the experiment are intrinsically connected and all indicate the mechanism that the flux effect stems from multiple ion-induced pulses functioning together and relies exquisitely on the specific response of the device.
基金supported by International Thermonuclear Experimental Reactor(ITER) program special(Grant No.2013GB114003)National Natural Science Foundation of China(project approval Nos.11275135,11475122)
文摘A high-flux linear plasma device in Sichuan University plasma-surface interaction（SCU-PSI）based on a cascaded arc source has been established to simulate the interactions between helium and hydrogen plasma with the plasma-facing components in fusion reactors.In this paper,the helium plasma has been characterized by a double-pin Langmuir probe.The results show that the stable helium plasma beam with a diameter of 26 mm was constrained very well at a magnetic field strength of 0.3 T.The core density and ion flux of helium plasma have a strong dependence on the applied current,magnetic field strength and gas flow rate.It could reach an electron density of1.2×10^19m^-3and helium ion flux of 3.2×10^22m^-2s^-1,with a gas flow rate of 4 standard liter per minute,magnetic field strength of 0.2 T and input power of 11 k W.With the addition of-80 Vapplied to the target to increase the helium ion energy and the exposure time of 2 h,the flat top temperature reached about 530°C.The different sizes of nanostructured fuzz on irradiated tungsten and molybdenum samples surfaces under the bombardment of helium ions were observed by scanning electron microscopy.These results measured in the SCU-PSI linear device provide a reference for International Thermonuclear Experimental Reactor related PSI research.
文摘One of the earliest events leading to cell activation and growth is the hydrolysis of inositol phospholipids producing various membrane signals induced by an interaction between growth factors or hormones with their respective receptors on the cell membrane [1]. To demonstrate the mitogenio action of transferrin, our results show that an addition of transferrin to 'serum-deprived' rat hepatoma cells produced a rapid but transient rise in inositol 1, 4, 5-trisphosphate (IP3) level, and at the same time, an increased intraoellular Oa2+ activity and a oytoplasmic alkalinization were observed. These signal transduo-tions further lend support to the mitogenic nature of transferrin. In addition, a possible link between the receptor-mediated endocytosis of transferrin with the generation of intraoellular signals is discussed herewith.
基金supported by Shenyang Science and Technology Plan of China(No.F12028200)
文摘The significant role of ion beam flux during nitriding 304 austenitic stainless steel has been investigated by using a radio frequency inductively-coupled plasma reactor into which a sample with negative bias voltage was inserted. A milliammeter is used to detect tile current of ions which collide with the sample and optical emission spectroscopy is used to discern the reactive species included in the nitrogen plasma. The nitriding efficiency is indicated by X-ray diffraction and the microhardness test. The reported data reveal that the ion beam flux density as well as the deposition pressure, bias voltage and time can strongly affect the nitriding of stainless steel via tile expanded multiphase microstructure inside the nitrided layer. The increase in the density of ion flux results in an ascent in the intensity of the expanded peak and a simultaneous decline in the intensity of the 3＇ austenite peak. The evolution trend of ion beam flux density is described as a function of tile operating pressure and the bias voltage. The maxinmm ion flux density has been achieved at 10 Pa pressure and 500 V bias voltage. A reasonable nitriding region has been, consequently, suggested after comparing this work with previously reported results.
文摘In this work, study of laser-induced ions is presented. The plasma was produced by focusing a Nd：YAG laser, with a wavelength of 1064 nm, a pulsed width of 9-14 ns, a power of 1.1 MW and energy of 10 mJ, on silver target in vacuum （10-3 Torr= 1.3332 Pa）. The characteristics of ion streams were investigated by CR-39 detectors located at angles of 0°, 30°, 60° and 90° with respect to normal of the target. The distance between the silver target and each detector was 11 cm. The energy of silver ions was found ranging from 1.5 eV to 1.06E4 eV. There was a high concentration of ions with low energy as compared to those with high energy, showing the energy distribution amongst the ions. The flux of ions was maximum in the axial direction which was decreasing with the angle increase with respect to normal of the target, and finally became minimum in the radial direction. Hence the silver ions have shown anisotropic behaviour.
基金supported by a research grant of China National Space Administration project D020303,NSFC Grant Numbers:41974191the National Key R&D Program of China 2020YFE0202100。
文摘During geomagnetically active times such as geomagnetic storms,large amounts of energy can be released into the Earth’s magnetosphere and change the ring current intensity.Previous studies showed that significant enhancement of the ring current was related to geomagnetic storms,while few studies have examined substorm effects on ring current dynamics.In this study,we examine the ring current variation during non-storm time(SYM-H>−50 nT)substorms,especially during super-substorms(AE>1000 nT).We perform a statistical analysis of ring current plasma pressure and number flux of various ion species under different substorm conditions,based on Van Allen Probe observations.The plasma pressure and ion fluxes of the ring current increased dramatically during supersubstorms,while little change was observed for substorms with AE<1000 nT.The results shown in this study indicate that a non-storm time super-substorm may also have a significant contribution to the ring current.
基金supported by National Natural Science Foundation of China(No.51977110)。
文摘To understand the characteristics of the plasma sheath within small tubes,a 2D numerical model of He discharge within dielectric tubes is developed.During plasma propagation for a tube diameter of 0.05 mm,the sheath thickness in the plasma head is almost equal to the tube radius.It decreases rapidly to several micrometers at an axial distance of 0.05 mm behind the plasma head,and then slightly increases and saturates at the axial position far behind the plasma head.A plasma-gas sheath surrounding the central plasma column is observed for a tube diameter equal to or greater than 0.8 mm.It is replaced by a plasma-wall sheath for smaller tubes.With the decrease in the tube diameter,the sheath thickness far behind the plasma head decreases while the ion flux increases significantly.However,when O_(2)gas with a proportion of 2%is added,both the sheath thickness and ion flux decrease.
基金supported by Comprehensive Research Facility for Fusion Technology Program of China (No. 2018000052-73-01001228)the Youth Innovation Promotion Association CAS (No. 2018484)
文摘A new compact cascaded arc device for plasma-wall interaction study is developed at the Institute of Plasma Physics,Chinese Academy of Sciences.A magnetic field up to 0.8 T is achieved to confine plasmas in a 1.2 m long and 0.1 m diameter vacuum chamber.Gas fluid type analysis in this compact vacuum system was done under high particle flux condition.The gas pressure obtained by calculation was consistent with the measurement result.Continuous argon plasma discharge with ion flux of~0.5×10^(24)m^(-2)s^(-1)is successfully sustained for more than 1h.The effects of magnetic field configuration,gas flow rate,and discharge arc current on the ion flux to target were studied in detail.
基金This work was supported financially by the National Natural Science Foundation of China(31370351 and 30870237)the Doctoral Program of Higher Education of the Special Research Doctoral Advisor Fund of China(20110008110035).
文摘Maintenance of ion homeostasis,particularly the regulation of K^(+)and Na^(+)uptake,is important for all plants to adapt to salinity.Observations on ionic response to salinity and net fluxes of K^(+),Na^(+)in the root exhibited by plants during salt stress have highlighted the need for further investigation.The objectives of this study were to compare salt adaptation of two Chinese Iris(Iris lactea Pall.var.chinensis(Fisch.)Koidz.)populations,and to improve understanding of adaptation to salinity exhibited by plants.Plants used in this study were grown from seeds collected in the Xinjiang Uygur Autonomous Region(Xj)and Beijing Municipality(Bj),China.Hydroponicallygrown seedlings of the two populations were supplied with nutrient solutions containing 0.1(control)and 140 mmol·L^(–1) NaCl.After 12 days,plants were harvested for determination of relative growth rate and K^(+),Na^(+)concentrations.Net fluxes of K^(+),Na^(+)from the apex and along the root axis to 10.8 mm were measured using noninvasive micro-test technique.With 140 mmol·L^(–1) NaCl treatment,shoots for population Xj had larger relative growth rate and higher K^(+)concentration than shoots for population Bj.However,the Na^(+)concentrations in both shoots and roots were lower for Xj than those for Bj.There was a lower net efflux of K^(+)found in population Xj than by Bj in the mature zone(approximately 2.4^(–1)0.8 mm from root tip).However,no difference in the efflux of Na^(+)between the populations was obtained.Population Xj of I.lactea continued to grow normally under NaCl stress,and maintained a higher K^(+)/Na^(+)ratio in the shoots.These traits,which were associated with lower K^(+)leakage,help population Xj adapt to saline environments.
基金supported by the Grain Research and Development Corporation grant to S.S. and M.Z.by the Australian Research Council Discovery grant to S.S
文摘Plant salinity tolerance is a physiologically complex trait, with numerous mechanisms contributing to it. In this work, we show that the ability of leaf mesophyll to retain K＋ represents an important and essentially overlooked component of a salinity tolerance mechanism. The strong positive correlation between mesophyll K＋ retention ability under saline conditions （quantified by the magnitude of NaCl-induced K＋ efflux from mesophyll） and the overall salinity tolerance （relative fresh weight and/or survival or damage under salinity stress） was found while screening 46 barley （Hordeum vulgare L.） genotypes contrasting in their salinity tolerance. Genotypes with intrinsically higher leaf K＋ content under control conditions were found to possess better K＋ retention ability under salinity and, hence, overall higher tolerance. Contrary to previous reports for barley roots, K＋ retention in mesophyll was not associated with an increased H＋-pumping in tolerant varieties but instead correlated negatively with this trait. These findings are explained by the fact that increased H＋ extrusion may be needed to charge balance the activity and provide the driving force for the high affinity HAK/KUP K＋ transporters required to restore cytosolic K＋ homeostasis in salt-sensitive genotypes.
基金the financial support provided by the National Natural Science Foundation of China (Nos. 21971113, 22175094, 51902165)the Natural Science Foundation of Jiangsu Province (No. BK20200800)+1 种基金Independent Innovation of Agricultural Science and Technology in Jiangsu Province (No. CX(21)3163)Natural Science Foundation of the Jiangsu Higher Education Institutions (No. 20KJA150001)。
文摘Li metal has been regarded as the holy grail for the next-generation Li-ion battery.Li dendrites issues,however,impede its practical application.In general,prolonging the sand time of Li nucleation and regulating homogeneous Li^(+) flux are effective approaches to suppress the dendrites formation and growth.Regarding this view,a functional polypropylene (PP) separator is developed to regulate ion transportation via a newly designed Li-based metal-organic framework (Li-MOF) coating.The Li-MOF crystallizes in the orthorhombic space group P212121 and features a double-walled three-dimensional (3D) structure with 1D channels.The well-defined intrinsic nanochannels of Li-MOF and the steric-hinerance effect both restrict free migration of anions,contributing to a high Li^(+) transference number of 0.65,which improve the Sand time of Li nucleation.Meanwhile,the Li-MOF coating with uniform porous structure promotes homogeneous Li^(+) flux at the surface of Li metal.Furthermore,the Li-MOF coating layer helps to build solid-electrolyte interphase (SEI) layer that comprises of inorganic Li F and Li_(3)N,which further prohibits the dendrites growth.Consequently,a highly stable Li plating/stripping cycling for over 1000 h is achieved.The functional separator also enables high-performance full lithium metal cells,the high-rate and long-stable cycling performance of Li Ni_(0.8)Mn_(0.1)Co_(0.1)(NMC811)-Li and Li Co O_(2)(LCO)-Li cells further demonstrate the feasibility of this concept.
基金This work was supported by the National Natural Science Foundation of China ( Grant No. 49884002) .
文摘Based on the comparison with the Earth, using the LB magnetic field model, the distribution of O+ ion originating from the ionosphere in the Martian magnetosphere is theoretically studied under different conditions of the tail-like magnetic field. The results show that the tail-like magnetic field has influence on the O+ ion flux in the Martian magnetotail: (i) the O+ ion flux in the Martian tail will increase if the tail-like magnetic field increases; when the tail-like magnetic field increases from 5 nT to 20 nT, the O+ ion flux increases 3 times in the region of 2.8R m in the Martian tail; and (ii) the O+ ion flux decreases with increasing intrinsic moment; when the intrinsic moment increases about 5 times, the flux decreases to one fourth in the region of 2.8R m in the Martian tail. According to the data on the O+ ion flux and theoretical result in this paper, the deduced Martian intrinsic moment is about 2 ×1021 Gcm3. This is consistent with the most recent observation by the USA satellite MGS.
基金support from the Department of Industry,Science,Energy and Resources(project AISRF48490)China National Distinguished Expert Project(WQ20174400441)+5 种基金grant 31961143001 for Joint Research Projects between Pakistan Science Foundation and National Natural Science Foundation,and Chinese National Natural Science Foundation(Project 31870249)Zhong-Hua Chen was supported by Australian Research Council(DE140101143FT210100366)by Hort Innovation Australia Projects(VG17003,LP18000)Gayatri Venkataraman acknowledges support from the Department of Biotechnology,GOI(BT/Indo-Aus/09/03/2015)Sergey Shabala also acknowledges the support provided by the National Biodiversity Authority(NBA),India Government in assisting with O.coarctata material transfer(Appl.no.1712).
文摘Species of wild rice(Oryza spp.)possess a wide range of stress tolerance traits that can be potentially utilized in breeding climate-resilient cultivated rice cultivars(Oryza sativa)thereby aiding global food security.In this study,we conducted a greenhouse trial to evaluate the salinity tolerance of six wild rice species,one cultivated rice cultivar(IR64)and one landrace(Pokkali)using a range of electrophysiological,imaging,and whole-plant physiological techniques.Three wild species(O.latifolia,O.officinalis and O.coarctata)were found to possess superior salinity stress tolerance.The underlying mechanisms,however,were strikingly different.Na+accumulation in leaves of O.latifolia,O.officinalis and O.coarctata were significantly higher than the tolerant landrace,Pokkali.Na+accumulation in mesophyll cells was only observed in O.coarctata,suggesting that O.officinalis and O.latifolia avoid Na+accumulation in mesophyll by allocating Na+to other parts of the leaf.The finding also suggests that O.coarctata might be able to employ Na+as osmolyte without affecting its growth.Further study of Na+allocation in leaves will be helpful to understand the mechanisms of Na+accumulation in these species.In addition,O.coarctata showed Proto Kranz-like leaf anatomy(enlarged bundle sheath cells and lower numbers of mesophyll cells),and higher expression of C4-related genes(e.g.,NADPME,PPDK)and was a clear outlier with respect to salinity tolerance among the studied wild and cultivated Oryza species.The unique phylogenetic relationship of O.coarctata with C4 grasses suggests the potential of this species for breeding rice with high photosynthetic rate under salinity stress in the future.
基金supported by the Key-Area Research and Development Program of Guangdong Province(2020B090919005)the National Natural Science Foundation of China(21975274 and 52101276)+4 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA22010600)Shandong Provincial Natural Science Foundation(ZR2020KE032 and ZR2022QB160)the Youth Innovation Promotion Association of CAS(2021210)the Shandong Energy Institute(SEI)(SEI I202117)Parts of the work were also supported by the BMWi/BMWK project HiBrain(03ET039G)。
基金the National Natural Science Foundation of China for providing financial support(Nos.51374060 and 51374059)
文摘The influence of fluorine on the structure of CaO Si（）e-Al2Oa Na2O-CaF2 continuous-casting-type slag was measured by Raman spectroscopy, and the degree of polymerization of mould flux and the structural behavior of F- in the melt were investigated by classifying and quantifying the structural species of F ions. The results exhibit that the main structural units of Si O tetrahedra are Q1, Q1 and Q2, and the actual measured number of non bridging oxygen ions in the [SiO4 ]-tetrahedra （denoted by NBO/T） in creases from 2. 73 to 3.44 with increasing the molar ratio of F to （F＋O） （denoted by XF/X（F-O ） from 0.06 to 0. 19. It means that the degree of polymerization o1 meh structure decreases with an increase in XE/X（F＋O）. In addition, most of F- ions were distributed in Si-O tetrahedra and Al-O tetrahedra. With increasing XF/X（F＋O）, the complex structural units Al-Otetrahedra are gradually replaced hy discrete structural units A1F4 because of the breakage of Al-O bonds in Al-Otetrahedra by F ions, and the SiO （bridging oxygen） bonds of SiO tetrahedra are broken to form [SiOnF1-n]-tetrahedra by F ions coordinating with Si4 ＋ .
