The ion conductivity of a solid-state ion conductor generally increases exponentially upon reduction in ionmigration barrier.For prevalent cathode material LiCoO_(2),the room-temperature ion conductivity and migration...The ion conductivity of a solid-state ion conductor generally increases exponentially upon reduction in ionmigration barrier.For prevalent cathode material LiCoO_(2),the room-temperature ion conductivity and migrationbarrier are respectively around 10^(−4)S/cm and 0.3 eV.In this Letter,through first-principles calculations we predictthe existence of 1D superionicity as the Li ions in O_(2)LiCoO_(2)are transformed into Zn_(0.5)CoO_(2)or Li_(0.5)CoO_(2)via cation-exchange reaction or deintercalation.The ion migration barriers(0.01-0.02 eV)even lower than roomtemperature∼𝑘B𝑇are reduced by more than an order of magnitude compared with LiCoO_(2),which are facilitatedby facile transition of mobile ions between two coordination configurations.The room-temperature ion conductivityis estimated to be over 50 S/cm,enhanced by 2-3 orders of magnitude compared with the current highestreported value.Such unprecedented superionicity may also exist in other similar layered ion conductors,whichmay lead to technical advances and exotic effects such as ultrafast ion batteries and quantized ferroelectricity.展开更多
Laser-driven ion acceleration,as produced by interaction of a high-intensity laser with a target,is a growing field of interest.One of the current challenges is to enhance the acceleration process,i.e.,to increase the...Laser-driven ion acceleration,as produced by interaction of a high-intensity laser with a target,is a growing field of interest.One of the current challenges is to enhance the acceleration process,i.e.,to increase the produced ion energy and the ion number and to shape the energy distribution for future applications.In this paper,we investigate the effect of helical coil(HC)targets on the laser-matter interaction process using a 150 TW laser.We demonstrate that HC targets significantly enhance proton acceleration,improving energy bunching and beam focusing and increasing the cutoff energy.For the first time,we extend this analysis to carbon ions,revealing a marked reduction in the number of low-energy carbon ions and the potential for energy bunching and post-acceleration through an optimized HC design.Simulations using the particle-in-cell code SOPHIE confirm the experimental results,providing insights into the current propagation and ion synchronization mechanisms in HCs.Our findings suggest that HC targets can be optimized for multispecies ion acceleration.展开更多
Micro-sized anatase TiO_(2) displays inferior capacity as cathode material for magnesium ion batteries because of the higher diffusion energy barrier of Mg^(2+)in anatase TiO_(2) lattice.Herein,we report that nanosize...Micro-sized anatase TiO_(2) displays inferior capacity as cathode material for magnesium ion batteries because of the higher diffusion energy barrier of Mg^(2+)in anatase TiO_(2) lattice.Herein,we report that nanosized anatase TiO_(2) exposed(001)facet doubles the capacity compared to the micro-sized sample ascribed to the interfacial Mg^(2+)ion storage.First-principles calculations reveal that the diffusion energy barrier of Mg^(2+)on the(001)facet is significantly lower than those in the bulk phase and on(100)facet,and the adsorption energy of Mg^(2+)on the(001)facet is also considerably lower than that on(100)facet,which guarantees superior interfacial Mg^(2+)storage of(001)facet.Moreover,anatase TiO_(2) exposed(001)facet displays a significantly higher capacity of 312.9 mAh g^(−1) in Mg-Li dual-salt electrolyte compared to 234.3 mAh g^(−1) in Li salt electrolyte.The adsorption energies of Mg^(2+)on(001)facet are much lower than the adsorption energies of Li+on(001)facet,implying that the Mg^(2+)ion interfacial storage is more favorable.These results highlight that controlling the crystal facet of the nanocrystals effectively enhances the interfacial storage of multivalent ions.This work offers valuable guidance for the rational design of high-capacity storage systems.展开更多
Composite polymer electrolytes(CPEs)offer a promising solution for all-solid-state lithium-metal batteries(ASSLMBs).However,conventional nanofillers with Lewis-acid-base surfaces make limited contribution to improving...Composite polymer electrolytes(CPEs)offer a promising solution for all-solid-state lithium-metal batteries(ASSLMBs).However,conventional nanofillers with Lewis-acid-base surfaces make limited contribution to improving the overall performance of CPEs due to their difficulty in achieving robust electrochemical and mechanical interfaces simultaneously.Here,by regulating the surface charge characteristics of halloysite nanotube(HNT),we propose a concept of lithium-ion dynamic interface(Li^(+)-DI)engineering in nano-charged CPE(NCCPE).Results show that the surface charge characteristics of HNTs fundamentally change the Li^(+)-DI,and thereof the mechanical and ion-conduction behaviors of the NCCPEs.Particularly,the HNTs with positively charged surface(HNTs+)lead to a higher Li^(+)transference number(0.86)than that of HNTs-(0.73),but a lower toughness(102.13 MJ m^(-3)for HNTs+and 159.69 MJ m^(-3)for HNTs-).Meanwhile,a strong interface compatibilization effect by Li^(+)is observed for especially the HNTs+-involved Li^(+)-DI,which improves the toughness by 2000%compared with the control.Moreover,HNTs+are more effective to weaken the Li^(+)-solvation strength and facilitate the formation of Li F-rich solid-electrolyte interphase of Li metal compared to HNTs-.The resultant Li|NCCPE|LiFePO4cell delivers a capacity of 144.9 m Ah g^(-1)after 400 cycles at 0.5 C and a capacity retention of 78.6%.This study provides deep insights into understanding the roles of surface charges of nanofillers in regulating the mechanical and electrochemical interfaces in ASSLMBs.展开更多
In order to better build the neutral beam injector with negative ion source(NNBI),the pre-research on key technologies has been carried out for the comprehensive research facility for fusion technology(CRFFT).Cesium s...In order to better build the neutral beam injector with negative ion source(NNBI),the pre-research on key technologies has been carried out for the comprehensive research facility for fusion technology(CRFFT).Cesium seeding into negative-ion sources is a prerequisite to obtain the required negative hydrogen ion.The performance of ion source largely depends on the cesium conditions in the source.It is very necessary to quantitatively measure the amount of cesium in the source during the plasma on and off periods(vacuum stage).展开更多
Refractory high entropy alloys(RHEAs)have drawn much attention for their potential applications in ad-vanced reactors.While improved irradiation resistance to void swelling and helium bubble formation has been frequen...Refractory high entropy alloys(RHEAs)have drawn much attention for their potential applications in ad-vanced reactors.While improved irradiation resistance to void swelling and helium bubble formation has been frequently reported,experimental investigation regarding their early-stage irradiation damage re-mains insufficient,which hinders the understanding of the behavior of point defects and small clusters.Here we select two typical RHEAs with desired mechanical properties,VTaTi and HfNbZrTi,as well as a conventional V-4Cr-4Ti alloy,and compare their irradiation-induced defect production and hardening under a low-dose irradiation to~0.1 dpa.Significant hardening is observed in V-4Cr-4Ti due to the pin-ning of deformation-induced dislocations by the high density of irradiation-induced loops.In contrast,the hardening in VTaTi is much weaker,corresponding well to the greatly reduced defect density.Strikingly,in HfNbZrTi,visible defect clusters are not observed with a Cs-corrected transmission electron microscope in the whole irradiation range,and no hardening effect is detected.Such strong suppression of irradia-tion damage is attributed to the large lattice distortion based on the ab initio calculations and the local chemical fluctuations based on the atomic-scale elemental mappings,which together hinder the mobility of interstitials.Furthermore,minor irradiation softening is evidenced by cross-sectional nanoindentation tests in HfNbZrTi,which is considered to be related to the evolution of short-range orders and interstitial impurities after irradiation.展开更多
In the past few decades,ion engines have been widely used in deep-space propulsion and satellite station-keeping.The aim of extending the thruster lifetime is still one of the most important parts during the design st...In the past few decades,ion engines have been widely used in deep-space propulsion and satellite station-keeping.The aim of extending the thruster lifetime is still one of the most important parts during the design stage of ion engine.As one of the core components of ion engine,the grid assembly of ion optic systems may experience long-term ion sputtering in extreme electro-thermal environments,which will eventually lead to its structural and electron-backstreaming failures.In this paper,the current studies of the grid assembly erosion process are systematically analyzed from the aspects of sputtering damage process of grid materials,numerical simulations,and measurements of erosion characteristics of grid assembly.The advantages and disadvantages of various erosion prediction models are highlighted,and the key factors and processes affecting the prediction accuracy of grid assembly erosion patterns are analyzed.Three different types of experimental methods of grid assembly erosion patterns are compared.The analysis in this paper is of great importance for selecting the sputter-resistant grid materials,as well as establishing the erosion models and measurement methods to accurately determine the erosion rate and failure modes of grid assembly.Consequently,the working conditions and structure parameters of ion optic systems could be optimized based on erosion models to promote the ion engine lifetime.展开更多
Dear Editor,Health management is essential to ensure battery performance and safety, while data-driven learning system is a promising solution to enable efficient state of health(SoH) estimation of lithium-ion(Liion) ...Dear Editor,Health management is essential to ensure battery performance and safety, while data-driven learning system is a promising solution to enable efficient state of health(SoH) estimation of lithium-ion(Liion) batteries. However, the time-consuming signal data acquisition and the lack of interpretability of model still hinder its efficient deployment. Motivated by this, this letter proposes a novel and interpretable data-driven learning strategy through combining the benefits of explainable AI and non-destructive ultrasonic detection for battery SoH estimation. Specifically, after equipping battery with advanced ultrasonic sensor to promise fast real-time ultrasonic signal measurement, an interpretable data-driven learning strategy named generalized additive neural decision ensemble(GANDE) is designed to rapidly estimate battery SoH and explain the effects of the involved ultrasonic features of interest.展开更多
Sodium-ion batteries have emerged as promising alternatives to lithium-ion batteries due to their abundant raw material reserves,low cost,enhanced safety,and environmental sustainability.Na_(2)Fe_(2)OS_(2),featuring a...Sodium-ion batteries have emerged as promising alternatives to lithium-ion batteries due to their abundant raw material reserves,low cost,enhanced safety,and environmental sustainability.Na_(2)Fe_(2)OS_(2),featuring a layered anti-perovskite structure,has attracted significant interest for its high capacity and facile synthesis.In this study,density functional theory calculations were performed to systematically investigate the phase stability,ionic conductivity,and voltage characteristics of Na_(2)Fe_(2)OS_(2)as a model system for anti-perovskite layered cathode materials.The compound exhibits excellent phase stability,and its equilibrium potential was calculated for the series Na_(x)Fe_(2)OCh_(2)(0<±<2)(where Ch represents chalcogenides).Naion transport analysis using the climbing image nudged elastic band method reveals a relatively low migration barrier(~0.47eV)along a dingonal pathway,indicating efficient Na^(+)mobility.To expand the materials design space,we systematically explored the effects of substituting Fe with various transition metals and replacing S with Se in NaaTM_(2)OCh_(2)structures.Among the variants studied,Na_(2)Mn_(2)OS_(2) demonstrates the most favorable combination of high voltage(~2.51V),robust phase stability,and superior energy density(~427 W-h/kg).This comprehensive comparison of transition metal substitutions provides vnluable insights for the rational design and experimental development of next-generation anti-perovskite layered cathode materials for sodium-ion batteries.展开更多
Trapped-ion systems are one of the leading platforms for quantum information processing, where a key challenge is to scale up system size while maintaining high-fidelity two-qubit operations. A promising approach is t...Trapped-ion systems are one of the leading platforms for quantum information processing, where a key challenge is to scale up system size while maintaining high-fidelity two-qubit operations. A promising approach is to build high-performance modules interconnected via strong coupling. In particular, axial motional modes offer a practical mechanism to couple the ions in a chain, enabling the preparation of Greenberger–Horne–Zeilinger states with up to 24 ions using global operations, as well as high-fidelity two-qubit gates(96.6%–98.0%) in fully connected five-ion chains. Here, we demonstrate two-qubit quantum logic gates in a 5-ion^(40)Ca^(+)chain using axial modes, achieving fidelities exceeding 99% for adjacent pairs and over 98% for arbitrary pairs by carefully tackling dominant error sources. Our results are beneficial to the development of scalable ion-trap quantum processors,quantum simulation and quantum-enhanced metrology.展开更多
Biomineralization has garnered significant attention in the field of wastewater treatment due to its notable cost reduction compared to conventional methods.The reinjection water from oilfields containing an exceeding...Biomineralization has garnered significant attention in the field of wastewater treatment due to its notable cost reduction compared to conventional methods.The reinjection water from oilfields containing an exceedingly high concentration of calcium and ferric ions will pose amajor hazard in production.However,the utilization of biomineralization for precipitating these ions has been scarcely investigated due to limited tolerance among halophiles towards such extreme conditions.In this study,free and immobilized halophiles Virgibacillus dokdonensis were used to precipitate these ions and the effects were compared,at the same time,biomineralizationmechanisms and mineral characteristicswere further explored.The results showthat bacterial concentration and carbonic anhydrase activitywere higher when additionally adding ferric ion based on calcium ion;the content of protein,polysaccharides,deoxyribonucleic acid and humic substances in the extracellular polymers also increased compared to control.Calcium ions were biomineralized into calcite and vaterite with mul-tiple morphology.Due to iron doping,the crystallinity and thermal stability of calcium carbonate decreased,the content of O-C=O,N-C=OandC-O-PO_(3) increased,the stable carbon isotope values became much more negative,andβ-sheet in minerals disappeared.Higher calcium concentrations facilitated ferric ion precipitation,while ferric ions hindered calcium precipitation.The immobilized bacteria performed better in ferric ion removal,with a precipitation ratio exceeding 90%.Free bacteria performed better in calcium removal,and the precipitation ratio reached a maximum of 56%.This research maybe provides some reference for the co-removal of calcium and ferric ions from the oilfield wastewater.展开更多
This work demonstrates experimentally the close relation between return currents from relativistic laser-driven target polarization and the quality of the relativistic laser–plasma interaction for laser-driven second...This work demonstrates experimentally the close relation between return currents from relativistic laser-driven target polarization and the quality of the relativistic laser–plasma interaction for laser-driven secondary sources,taking as an example ion acceleration by target normal sheath acceleration.The Pearson linear correlation of maximum return current amplitude and proton spectrum cutoff energy is found to be in the range from~0.70 to 0.94.kA-scale return currents rise in all interaction schemes where targets of any kind are charged by escaping laser-accelerated relativistic electrons.Their precise measurement is demonstrated using an inductive scheme that allows operation at high repetition rates.Thus,return currents can be used as a metrological online tool for the optimization of many laser-driven secondary sources and for diagnosing their stability.In particular,in two parametric studies of laser-driven ion acceleration,we carry out a noninvasive online measurement of return currents in a tape target system irradiated by the 1 PW VEGA-3 laser at Centro de Láseres Pulsados:first the size of the irradiated area is varied at best compression of the laser pulse;second,the pulse duration is varied by means of induced group delay dispersion at best focus.This work paves the way to the development of feedback systems that operate at the high repetition rates of PW-class lasers.展开更多
Imprinted polymers were prepared for selective removal of Cu（Ⅱ） ions from metal solutions. Three ion-imprinted polymers were synthesized with methacrylic acid （MAA）, acrylamide （AA） and N,N＇-methylenebisacryla...Imprinted polymers were prepared for selective removal of Cu（Ⅱ） ions from metal solutions. Three ion-imprinted polymers were synthesized with methacrylic acid （MAA）, acrylamide （AA） and N,N＇-methylenebisacrylamide （MBAA） respectively as the functional monomers, ethleneglycoldimethacrylate （EGDMA） as the cross-linking agent, 2,2＇- azobisisobutyronitrile （AIBN） as the initiator and Cu （Ⅱ） ion as the imprint ion. The template Cu （Ⅱ） ion was removed from the polymer by leaching with a liquid of a 1：1 volumetric ratio of HCl to ethylenediaminetetraacetic acid （EDTA）. The capacity and selectivity of Cu（Ⅱ） ion adsorption were investigated with the three imprinted polymers and their non-imprinted counterparts. The polymers have a maximum adsorption capacity at pH 7.0. The isotherm of their batch adsorption of Cu（Ⅱ） ions shows a Langmuir adsorption pattern. Imprinted polymers all have a much higher capacity and higher selectivity of Cu（Ⅱ） adsorption than nonimprinted ones. MAA polymer benefits the most from imprinting. Imprinted MAA polymer has the highest selectivity when used to rebind Cu （Ⅱ） ion from an aqueous solution in the presence of other metal ions. Ion imprinting can be a promising technique of preparing selective adsorbents to separate and preconcentrate metal in a medium of multiple competitive metal ions through solid phase extraction （SPE）.展开更多
Numerous pathological states of the nervous system involve alterations in neuronal excitability and synaptic dysfunction,which depend on the function of ion channels.Due to their critical involvement in health and dis...Numerous pathological states of the nervous system involve alterations in neuronal excitability and synaptic dysfunction,which depend on the function of ion channels.Due to their critical involvement in health and disease,the search for new compounds that modulate these proteins is still relevant.Traditional medicine has long been a rich source of neuroactive compounds.For example,the indigenous Mapuche people have used the leaves and bark of the Drimys winteri tree for centuries to treat various diseases.Consequently,several studies have investigated the biological effects of compounds in Drimys winteri,highlighting sesquiterpenes such asα-humulene,drimenin,polygodial,andα-,β-,γ-eudesmol.However,there is currently no literature review focusing on the ability of these sesquiterpenes to modulate ion channels.This review summarizes the current knowledge about neuroactive compounds found in Drimys winteri,with special emphasis on their direct actions on neuronal ion channels.Several Drimys winteri sesquiterpenes modulate a diverse array of neuronal ion channels,including transient receptor potential channels,gamma-aminobutyric acid A receptors,nicotinic acetylcholine receptors,and voltage-dependent Ca^(2+)and Na^(+)channels.Interestingly,the modulation of these molecular targets by Drimys winteri sesquiterpenes correlates with their therapeutic actions.The promiscuous pharmacological profile of Drimys winteri sesquiterpenes suggests they modulate multiple protein targets in vivo,making them potentially useful for treating complex,multifactorial diseases.Further studies at the molecular level may aid in developing multitargeted drugs with enhanced therapeutic effects.展开更多
In this review paper on heavy ion inertial fusion(HIF),the state-of-the-art scientific results are presented and discussed on the HIF physics,including physics of the heavy ion beam(HIB)transport in a fusion reactor,t...In this review paper on heavy ion inertial fusion(HIF),the state-of-the-art scientific results are presented and discussed on the HIF physics,including physics of the heavy ion beam(HIB)transport in a fusion reactor,the HIBs-ion illumination on a direct-drive fuel target,the fuel target physics,the uniformity of the HIF target implosion,the smoothing mechanisms of the target implosion non-uniformity and the robust target implosion.The HIB has remarkable preferable features to release the fusion energy in inertial fusion:in particle accelerators HIBs are generated with a high driver efficiency of~30%-40%,and the HIB ions deposit their energy inside of materials.Therefore,a requirement for the fusion target energy gain is relatively low,that would be~50-70 to operate a HIF fusion reactor with the standard energy output of 1 GWof electricity.The HIF reactor operation frequency would be~10-15 Hz or so.Several-MJ HIBs illuminate a fusion fuel target,and the fuel target is imploded to about a thousand times of the solid density.Then the DT fuel is ignited and burned.The HIB ion deposition range is defined by the HIB ions stopping length,which would be~1 mm or so depending on the material.Therefore,a relatively large density-scale length appears in the fuel target material.One of the critical issues in inertial fusion would be a spherically uniform target compression,which would be degraded by a non-uniform implosion.The implosion non-uniformity would be introduced by the Rayleigh-Taylor(R-T)instability,and the large densitygradient-scale length helps to reduce the R-T growth rate.On the other hand,the large scale length of the HIB ions stopping range suggests that the temperature at the energy deposition layer in a HIF target does not reach a very-high temperature:normally about 300 eV or so is realized in the energy absorption region,and that a direct-drive target would be appropriate in HIF.In addition,the HIB accelerators are operated repetitively and stably.The precise control of the HIB axis manipulation is also realized in the HIF accelerator,and the HIB wobbling motion may give another tool to smooth the HIB illumination non-uniformity.The key issues in HIF physics are also discussed and presented in the paper.展开更多
The electrophysiological properties of potassium ion channels are regarded as a basic index for determining the functional differentiation of neural stem cells. In this study, neural stem cells from the hippocampus of...The electrophysiological properties of potassium ion channels are regarded as a basic index for determining the functional differentiation of neural stem cells. In this study, neural stem cells from the hippocampus of newborn rats were induced to differentiate with neurotrophic growth factor, and the electrophysiological properties of the voltage-gated potassium ion channels were observed. Immunofluorescence staining showed that the rapidly proliferating neural stem cells formed spheres in vitro that expressed high levels of nestin. The differentiated neurons were shown to express neuron-specific enolase. Flow cytometric analysis revealed that the neural stem cells were actively dividing and the percentage of cells in the S ＋ G2/M phase was high. However, the ratio of cells in the S ＋ G2/M phase decreased obviously as differentiation proceeded. Whole-cell patch-clamp re- cordings revealed apparent changes in potassium ion currents as the neurons differentiated. The potassium ion currents consisted of one transient outward potassium ion current and one delayed rectifier potassium ion current, which were blocked by 4-aminopyridine and tetraethylammonium, respectively. The experimental findings indicate that neural stem cells from newborn rat hippo- campus could be cultured and induced to differentiate into functional neurons under defined condi- tions in vitro. The differentiated neurons expressed two types of outward potassium ion cur＇ents similar to those of mature neurons in vivo.展开更多
In this paper, we studied the process of dissociation unimolecular of the evaporation of H+2n+1 hydrogen clusters according to size, using the Rice-Ramsperger-Kassel-Marcus (RRKM) theory. The rate constants k(E) were ...In this paper, we studied the process of dissociation unimolecular of the evaporation of H+2n+1 hydrogen clusters according to size, using the Rice-Ramsperger-Kassel-Marcus (RRKM) theory. The rate constants k(E) were determined with the use of statistical theory of unimolecular reactions using various approximations. In our work, we used the products frequencies instead of transitions frequencies in the calculation of unimolecular dissociation rates obtained by three models RRKM. The agreement between the experimental cross section ratio and calculated rate ratio with direct count approximation seems to be reasonable.展开更多
MgATP is a stable complex formed by the chelation of Mg^(2+)with deprotonated adenosine-5'-triphosphate(ATP).In the cellular environment,MgATP plays a critical role in ATP hydrolysis,releasing substantial energy t...MgATP is a stable complex formed by the chelation of Mg^(2+)with deprotonated adenosine-5'-triphosphate(ATP).In the cellular environment,MgATP plays a critical role in ATP hydrolysis,releasing substantial energy to support essential biological functions.To understand the structure and stabilization mechanism of MgATP,we conducted a joint negative ion photoelectron spectroscopic and computational study of the[ATP^(4-)·Mg^(2+)]^(2-)complex dianion,using[ATP^(4-)·2H^(+)]^(2-)as a reference.The experimentally determined adiabatic and vertical detachment energies(ADE and VDE)of[ATP^(4-)·Mg^(2+)]^(2-)at 20 K are 3.51±0.05 eV and 3.82±0.05 eV,respectively.The major spectral features of[ATP^(4-)·Mg^(2+)]^(2-)are attributed to two theoretically identified isomers with unfolded geometries,which are stabilized primarily by electrostatic interactions between Mg^(2+)and the triphosphate and ribose groups,with four deprotonated oxygens forming a pseudo-tetrahedral coordination.In contrast,[ATP^(4-)·2H^(+)]^(2-)exhibits a fundamentally different stabilization mechanism.Although most of the fifteen identified[ATP^(4-)·2H^(+)]^(2-)isomers also adopt unfolded geometries,they are primarily stabilized by intramolecular hydrogen bonds within the triphosphate group and between triphosphate and ribose groups.The interaction between ATP^(4-)and two protons is found to be much weaker than that with Mg^(2+),and[ATP^(4-)·2H^(+)]^(2-)exhibits substantial structural flexibility compared to[ATP^(4-)·Mg^(2+)]^(2-)due to the conformational constraint of the triphosphate chain by Mg^(2+).Thirteen[ATP^(4-)·2H^(+)]^(2-)isomers with unfolded geometries likely account for the major high-EBE(electron-binding-energy)spectral features.Notably,for the first time,a low EBE and temperature-dependent spectral feature is observed and attributed to two folded isomers of[ATP^(4-)·2H^(+)]^(2-),which exist at 20 K but disappear at room temperature.This study provides valuable molecular-level insights into cellular MgATP that resides within the hydrophobic pockets of proteins.展开更多
We study the production of the X(6900)in the ultra-peripheral heavy ion collisions at the LHC energy region.The potential quantum numbers of X(6900)could be 0^(±+)and 2^(±+).We find that the transverse momen...We study the production of the X(6900)in the ultra-peripheral heavy ion collisions at the LHC energy region.The potential quantum numbers of X(6900)could be 0^(±+)and 2^(±+).We find that the transverse momentum and the polar angle distributions of X(6900)can be used to distinguish these four potential quantum numbers.These characteristic distributions originate from linearly polarized photons emitted by relativistic nuclei and can be measured by further LHC experiments.展开更多
We introduce a scheme aiming at the generation of quasi-monochromatic carbon ion bunches from laser-solid interaction.The proposed scheme is an extension of the“peeler”acceleration originally proposed for proton acc...We introduce a scheme aiming at the generation of quasi-monochromatic carbon ion bunches from laser-solid interaction.The proposed scheme is an extension of the“peeler”acceleration originally proposed for proton acceleration,which involves irradiating the narrow(submicrometer)side of a tape target.This results in the generation of a surface plasma wave and the subsequent acceleration of a proton bunch with high peak energy,quasi-monochromaticity,low energy bandwidth,and low divergence by the electrostatic field induced at the target rear.Up to now,the higher-Z(e.g.,carbon)ion bunches obtained with the peeler scheme have been found to exhibit an exponentially decaying thermal-like energy spectrum.To achieve a low energy bandwidth,we place a mass-limited carbon structure at the rear of the target.Using 3D particle-in-cell simulations,we show that a quasi-monochromatic carbon bunch can indeed be obtained.With a multi-PW laser pulse,10^(8) carbon ions with peak energy~110 MeV/u and with a divergence of 20° in the vertical plane and~1° in the horizontal plane can be generated.The quasi-monochromaticity,together with the low duration of the beam and in combination with the versatility of high-power laser facilities,should make this scheme attractive for practical applications such as heavy ion cancer therapy and higher-resolution diagnostics of extreme plasma states.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.22073034)。
文摘The ion conductivity of a solid-state ion conductor generally increases exponentially upon reduction in ionmigration barrier.For prevalent cathode material LiCoO_(2),the room-temperature ion conductivity and migrationbarrier are respectively around 10^(−4)S/cm and 0.3 eV.In this Letter,through first-principles calculations we predictthe existence of 1D superionicity as the Li ions in O_(2)LiCoO_(2)are transformed into Zn_(0.5)CoO_(2)or Li_(0.5)CoO_(2)via cation-exchange reaction or deintercalation.The ion migration barriers(0.01-0.02 eV)even lower than roomtemperature∼𝑘B𝑇are reduced by more than an order of magnitude compared with LiCoO_(2),which are facilitatedby facile transition of mobile ions between two coordination configurations.The room-temperature ion conductivityis estimated to be over 50 S/cm,enhanced by 2-3 orders of magnitude compared with the current highestreported value.Such unprecedented superionicity may also exist in other similar layered ion conductors,whichmay lead to technical advances and exotic effects such as ultrafast ion batteries and quantized ferroelectricity.
基金supported by the CEA/DAM Laser Plasma Experiments Validation Project and the CEA/DAM Basic Technical and Scientific Studies Projectsupported by the National Sciences and Engineering Research Council of Canada(NSERC)(Grant Nos.RGPIN-2023-05459 and ALLRP 556340-20)+3 种基金the Digital Research Alliance of Canada(Job pve-323-ac)the Canada Foundation for Innovation(CFI)the Ministère de l’Économie,de l’Innovation et de l’Énergie(MEIE)from QuébecThis study was granted access to the HPC resources of IRENE under allocation Grant No.A0170512899 made by GENCI.We acknowledge the financial support of the IdEx University of Bordeaux/Grand Research Program“GPR LIGHT”and of the Graduate Program on Light Sciences and Technologies of the University of Bordeaux.
文摘Laser-driven ion acceleration,as produced by interaction of a high-intensity laser with a target,is a growing field of interest.One of the current challenges is to enhance the acceleration process,i.e.,to increase the produced ion energy and the ion number and to shape the energy distribution for future applications.In this paper,we investigate the effect of helical coil(HC)targets on the laser-matter interaction process using a 150 TW laser.We demonstrate that HC targets significantly enhance proton acceleration,improving energy bunching and beam focusing and increasing the cutoff energy.For the first time,we extend this analysis to carbon ions,revealing a marked reduction in the number of low-energy carbon ions and the potential for energy bunching and post-acceleration through an optimized HC design.Simulations using the particle-in-cell code SOPHIE confirm the experimental results,providing insights into the current propagation and ion synchronization mechanisms in HCs.Our findings suggest that HC targets can be optimized for multispecies ion acceleration.
基金supported by the National Key R&D Program of China(No.2023YFB3809500)the Fundamental Research Funds for the Central Universities(No.2024CDJXY003)+1 种基金the Venture&Innovation Support Program for Chongqing Overseas Returnees(cx2023087)The Chongqing Technology Innovation and Application Development Project(No.2024TIAD-KPX0003).
文摘Micro-sized anatase TiO_(2) displays inferior capacity as cathode material for magnesium ion batteries because of the higher diffusion energy barrier of Mg^(2+)in anatase TiO_(2) lattice.Herein,we report that nanosized anatase TiO_(2) exposed(001)facet doubles the capacity compared to the micro-sized sample ascribed to the interfacial Mg^(2+)ion storage.First-principles calculations reveal that the diffusion energy barrier of Mg^(2+)on the(001)facet is significantly lower than those in the bulk phase and on(100)facet,and the adsorption energy of Mg^(2+)on the(001)facet is also considerably lower than that on(100)facet,which guarantees superior interfacial Mg^(2+)storage of(001)facet.Moreover,anatase TiO_(2) exposed(001)facet displays a significantly higher capacity of 312.9 mAh g^(−1) in Mg-Li dual-salt electrolyte compared to 234.3 mAh g^(−1) in Li salt electrolyte.The adsorption energies of Mg^(2+)on(001)facet are much lower than the adsorption energies of Li+on(001)facet,implying that the Mg^(2+)ion interfacial storage is more favorable.These results highlight that controlling the crystal facet of the nanocrystals effectively enhances the interfacial storage of multivalent ions.This work offers valuable guidance for the rational design of high-capacity storage systems.
基金the financial support from the National Natural Science Foundation of China(52203123 and 52473248)State Key Laboratory of Polymer Materials Engineering(sklpme2024-2-04)+1 种基金the Fundamental Research Funds for the Central Universitiessponsored by the Double First-Class Construction Funds of Sichuan University。
文摘Composite polymer electrolytes(CPEs)offer a promising solution for all-solid-state lithium-metal batteries(ASSLMBs).However,conventional nanofillers with Lewis-acid-base surfaces make limited contribution to improving the overall performance of CPEs due to their difficulty in achieving robust electrochemical and mechanical interfaces simultaneously.Here,by regulating the surface charge characteristics of halloysite nanotube(HNT),we propose a concept of lithium-ion dynamic interface(Li^(+)-DI)engineering in nano-charged CPE(NCCPE).Results show that the surface charge characteristics of HNTs fundamentally change the Li^(+)-DI,and thereof the mechanical and ion-conduction behaviors of the NCCPEs.Particularly,the HNTs with positively charged surface(HNTs+)lead to a higher Li^(+)transference number(0.86)than that of HNTs-(0.73),but a lower toughness(102.13 MJ m^(-3)for HNTs+and 159.69 MJ m^(-3)for HNTs-).Meanwhile,a strong interface compatibilization effect by Li^(+)is observed for especially the HNTs+-involved Li^(+)-DI,which improves the toughness by 2000%compared with the control.Moreover,HNTs+are more effective to weaken the Li^(+)-solvation strength and facilitate the formation of Li F-rich solid-electrolyte interphase of Li metal compared to HNTs-.The resultant Li|NCCPE|LiFePO4cell delivers a capacity of 144.9 m Ah g^(-1)after 400 cycles at 0.5 C and a capacity retention of 78.6%.This study provides deep insights into understanding the roles of surface charges of nanofillers in regulating the mechanical and electrochemical interfaces in ASSLMBs.
基金supported by the HFIPS Director’s Fund(Nos.YZJJQY202204 and 2021YZGH02)the Comprehensive Research Facility for Fusion Technology Program of China(No.2018-000052-73-01-001228)+1 种基金the Natural Science Foundation of Anhui Province(No.2208085MA19)the National Key R&D Program of China(Nos.2017YFE300103 and 2017YFE300503)。
文摘In order to better build the neutral beam injector with negative ion source(NNBI),the pre-research on key technologies has been carried out for the comprehensive research facility for fusion technology(CRFFT).Cesium seeding into negative-ion sources is a prerequisite to obtain the required negative hydrogen ion.The performance of ion source largely depends on the cesium conditions in the source.It is very necessary to quantitatively measure the amount of cesium in the source during the plasma on and off periods(vacuum stage).
基金supported by the National MCF En-ergy R&D Program of China(No.2022YFE03120000)the Na-tional Natural Science Foundation of China(Nos.12375266 and 12435016).
文摘Refractory high entropy alloys(RHEAs)have drawn much attention for their potential applications in ad-vanced reactors.While improved irradiation resistance to void swelling and helium bubble formation has been frequently reported,experimental investigation regarding their early-stage irradiation damage re-mains insufficient,which hinders the understanding of the behavior of point defects and small clusters.Here we select two typical RHEAs with desired mechanical properties,VTaTi and HfNbZrTi,as well as a conventional V-4Cr-4Ti alloy,and compare their irradiation-induced defect production and hardening under a low-dose irradiation to~0.1 dpa.Significant hardening is observed in V-4Cr-4Ti due to the pin-ning of deformation-induced dislocations by the high density of irradiation-induced loops.In contrast,the hardening in VTaTi is much weaker,corresponding well to the greatly reduced defect density.Strikingly,in HfNbZrTi,visible defect clusters are not observed with a Cs-corrected transmission electron microscope in the whole irradiation range,and no hardening effect is detected.Such strong suppression of irradia-tion damage is attributed to the large lattice distortion based on the ab initio calculations and the local chemical fluctuations based on the atomic-scale elemental mappings,which together hinder the mobility of interstitials.Furthermore,minor irradiation softening is evidenced by cross-sectional nanoindentation tests in HfNbZrTi,which is considered to be related to the evolution of short-range orders and interstitial impurities after irradiation.
基金co-supported by the National Key R&D Program of China(No.2022YFB3403500)the National Natural Science Foundation of China(No.NSFC52202460)the China Postdoctoral Science Foundation(Nos.2021M690392,2021TQ0036,and 2023TQ0031)。
文摘In the past few decades,ion engines have been widely used in deep-space propulsion and satellite station-keeping.The aim of extending the thruster lifetime is still one of the most important parts during the design stage of ion engine.As one of the core components of ion engine,the grid assembly of ion optic systems may experience long-term ion sputtering in extreme electro-thermal environments,which will eventually lead to its structural and electron-backstreaming failures.In this paper,the current studies of the grid assembly erosion process are systematically analyzed from the aspects of sputtering damage process of grid materials,numerical simulations,and measurements of erosion characteristics of grid assembly.The advantages and disadvantages of various erosion prediction models are highlighted,and the key factors and processes affecting the prediction accuracy of grid assembly erosion patterns are analyzed.Three different types of experimental methods of grid assembly erosion patterns are compared.The analysis in this paper is of great importance for selecting the sputter-resistant grid materials,as well as establishing the erosion models and measurement methods to accurately determine the erosion rate and failure modes of grid assembly.Consequently,the working conditions and structure parameters of ion optic systems could be optimized based on erosion models to promote the ion engine lifetime.
基金supported by the National Natural Science Foundation of China(62373224,62333013,U23A20327)the Natural Science Foundation of Shandong Province(ZR2024JQ021)
文摘Dear Editor,Health management is essential to ensure battery performance and safety, while data-driven learning system is a promising solution to enable efficient state of health(SoH) estimation of lithium-ion(Liion) batteries. However, the time-consuming signal data acquisition and the lack of interpretability of model still hinder its efficient deployment. Motivated by this, this letter proposes a novel and interpretable data-driven learning strategy through combining the benefits of explainable AI and non-destructive ultrasonic detection for battery SoH estimation. Specifically, after equipping battery with advanced ultrasonic sensor to promise fast real-time ultrasonic signal measurement, an interpretable data-driven learning strategy named generalized additive neural decision ensemble(GANDE) is designed to rapidly estimate battery SoH and explain the effects of the involved ultrasonic features of interest.
基金supported by the National Natural Science Foundation of China(Grant Nos.12404264 and 22209067)Shenzhen Basic Research Program(Natural Science Foundation)Key Project of Basic Research(Grant No.JCYJ20241202123916023)Shenzhen Science and Technology Program(Grant No.KQTD20200820113047086)。
文摘Sodium-ion batteries have emerged as promising alternatives to lithium-ion batteries due to their abundant raw material reserves,low cost,enhanced safety,and environmental sustainability.Na_(2)Fe_(2)OS_(2),featuring a layered anti-perovskite structure,has attracted significant interest for its high capacity and facile synthesis.In this study,density functional theory calculations were performed to systematically investigate the phase stability,ionic conductivity,and voltage characteristics of Na_(2)Fe_(2)OS_(2)as a model system for anti-perovskite layered cathode materials.The compound exhibits excellent phase stability,and its equilibrium potential was calculated for the series Na_(x)Fe_(2)OCh_(2)(0<±<2)(where Ch represents chalcogenides).Naion transport analysis using the climbing image nudged elastic band method reveals a relatively low migration barrier(~0.47eV)along a dingonal pathway,indicating efficient Na^(+)mobility.To expand the materials design space,we systematically explored the effects of substituting Fe with various transition metals and replacing S with Se in NaaTM_(2)OCh_(2)structures.Among the variants studied,Na_(2)Mn_(2)OS_(2) demonstrates the most favorable combination of high voltage(~2.51V),robust phase stability,and superior energy density(~427 W-h/kg).This comprehensive comparison of transition metal substitutions provides vnluable insights for the rational design and experimental development of next-generation anti-perovskite layered cathode materials for sodium-ion batteries.
基金supported by the Innovation Program for Quantum Science and Technology (Grant No.2021ZD0301603)the National Natural Science Foundation of China (Grant No.92165206)。
文摘Trapped-ion systems are one of the leading platforms for quantum information processing, where a key challenge is to scale up system size while maintaining high-fidelity two-qubit operations. A promising approach is to build high-performance modules interconnected via strong coupling. In particular, axial motional modes offer a practical mechanism to couple the ions in a chain, enabling the preparation of Greenberger–Horne–Zeilinger states with up to 24 ions using global operations, as well as high-fidelity two-qubit gates(96.6%–98.0%) in fully connected five-ion chains. Here, we demonstrate two-qubit quantum logic gates in a 5-ion^(40)Ca^(+)chain using axial modes, achieving fidelities exceeding 99% for adjacent pairs and over 98% for arbitrary pairs by carefully tackling dominant error sources. Our results are beneficial to the development of scalable ion-trap quantum processors,quantum simulation and quantum-enhanced metrology.
基金supported by the National Natural Science Foundation of China(Nos.42072136,41972108,and 42106144)the Natural Science Foundation of Shandong Province(Nos.ZR2023MD063,ZR2020MC041,and ZR2020QD089)+1 种基金the Key Laboratory of Marine Biogenetic Resources,Third Institute of Oceanography,Ministry of Natural Resources(No.SKDZK20230127)the Foreign visiting scholar funded by Shandong Provincial government.
文摘Biomineralization has garnered significant attention in the field of wastewater treatment due to its notable cost reduction compared to conventional methods.The reinjection water from oilfields containing an exceedingly high concentration of calcium and ferric ions will pose amajor hazard in production.However,the utilization of biomineralization for precipitating these ions has been scarcely investigated due to limited tolerance among halophiles towards such extreme conditions.In this study,free and immobilized halophiles Virgibacillus dokdonensis were used to precipitate these ions and the effects were compared,at the same time,biomineralizationmechanisms and mineral characteristicswere further explored.The results showthat bacterial concentration and carbonic anhydrase activitywere higher when additionally adding ferric ion based on calcium ion;the content of protein,polysaccharides,deoxyribonucleic acid and humic substances in the extracellular polymers also increased compared to control.Calcium ions were biomineralized into calcite and vaterite with mul-tiple morphology.Due to iron doping,the crystallinity and thermal stability of calcium carbonate decreased,the content of O-C=O,N-C=OandC-O-PO_(3) increased,the stable carbon isotope values became much more negative,andβ-sheet in minerals disappeared.Higher calcium concentrations facilitated ferric ion precipitation,while ferric ions hindered calcium precipitation.The immobilized bacteria performed better in ferric ion removal,with a precipitation ratio exceeding 90%.Free bacteria performed better in calcium removal,and the precipitation ratio reached a maximum of 56%.This research maybe provides some reference for the co-removal of calcium and ferric ions from the oilfield wastewater.
基金funding from the European Union’s Horizon 2020 research and innovation program through the European IMPULSE project under Grant Agreement No.871161from LASERLAB-EUROPE V under Grant Agreement No.871124+6 种基金from the Grant Agency of the Czech Republic(Grant No.GM23-05027M)Grant No.PDC2021120933-I00 funded by MCIN/AEI/10.13039/501100011033by the European Union Next Generation EU/PRTRsupported by funding from the Ministerio de Ciencia,Innovación y Universidades in Spain through ICTS Equipment Grant No.EQC2018-005230-Pfrom Grant No.PID2021-125389O A-I00 funded by MCIN/AEI/10.13039/501100011033/FEDER,UEby“ERDF A Way of Making Europe”by the European Unionfrom grants of the Junta de Castilla y León with Grant Nos.CLP263P20 and CLP087U16。
文摘This work demonstrates experimentally the close relation between return currents from relativistic laser-driven target polarization and the quality of the relativistic laser–plasma interaction for laser-driven secondary sources,taking as an example ion acceleration by target normal sheath acceleration.The Pearson linear correlation of maximum return current amplitude and proton spectrum cutoff energy is found to be in the range from~0.70 to 0.94.kA-scale return currents rise in all interaction schemes where targets of any kind are charged by escaping laser-accelerated relativistic electrons.Their precise measurement is demonstrated using an inductive scheme that allows operation at high repetition rates.Thus,return currents can be used as a metrological online tool for the optimization of many laser-driven secondary sources and for diagnosing their stability.In particular,in two parametric studies of laser-driven ion acceleration,we carry out a noninvasive online measurement of return currents in a tape target system irradiated by the 1 PW VEGA-3 laser at Centro de Láseres Pulsados:first the size of the irradiated area is varied at best compression of the laser pulse;second,the pulse duration is varied by means of induced group delay dispersion at best focus.This work paves the way to the development of feedback systems that operate at the high repetition rates of PW-class lasers.
基金the Natural Science Foundation of Hunan Province (No. 06JJ4117).
文摘Imprinted polymers were prepared for selective removal of Cu（Ⅱ） ions from metal solutions. Three ion-imprinted polymers were synthesized with methacrylic acid （MAA）, acrylamide （AA） and N,N＇-methylenebisacrylamide （MBAA） respectively as the functional monomers, ethleneglycoldimethacrylate （EGDMA） as the cross-linking agent, 2,2＇- azobisisobutyronitrile （AIBN） as the initiator and Cu （Ⅱ） ion as the imprint ion. The template Cu （Ⅱ） ion was removed from the polymer by leaching with a liquid of a 1：1 volumetric ratio of HCl to ethylenediaminetetraacetic acid （EDTA）. The capacity and selectivity of Cu（Ⅱ） ion adsorption were investigated with the three imprinted polymers and their non-imprinted counterparts. The polymers have a maximum adsorption capacity at pH 7.0. The isotherm of their batch adsorption of Cu（Ⅱ） ions shows a Langmuir adsorption pattern. Imprinted polymers all have a much higher capacity and higher selectivity of Cu（Ⅱ） adsorption than nonimprinted ones. MAA polymer benefits the most from imprinting. Imprinted MAA polymer has the highest selectivity when used to rebind Cu （Ⅱ） ion from an aqueous solution in the presence of other metal ions. Ion imprinting can be a promising technique of preparing selective adsorbents to separate and preconcentrate metal in a medium of multiple competitive metal ions through solid phase extraction （SPE）.
基金supported by ANID-FONDECYT 1200908(to JF),ANID-FONDECYT 1211082 and 1250856(to GEY)by the Millennium Nucleus for the Study of Pain NCN19_038(Mi Nu SPain)(to GEY)funded by the ANID scholarship 21201176。
文摘Numerous pathological states of the nervous system involve alterations in neuronal excitability and synaptic dysfunction,which depend on the function of ion channels.Due to their critical involvement in health and disease,the search for new compounds that modulate these proteins is still relevant.Traditional medicine has long been a rich source of neuroactive compounds.For example,the indigenous Mapuche people have used the leaves and bark of the Drimys winteri tree for centuries to treat various diseases.Consequently,several studies have investigated the biological effects of compounds in Drimys winteri,highlighting sesquiterpenes such asα-humulene,drimenin,polygodial,andα-,β-,γ-eudesmol.However,there is currently no literature review focusing on the ability of these sesquiterpenes to modulate ion channels.This review summarizes the current knowledge about neuroactive compounds found in Drimys winteri,with special emphasis on their direct actions on neuronal ion channels.Several Drimys winteri sesquiterpenes modulate a diverse array of neuronal ion channels,including transient receptor potential channels,gamma-aminobutyric acid A receptors,nicotinic acetylcholine receptors,and voltage-dependent Ca^(2+)and Na^(+)channels.Interestingly,the modulation of these molecular targets by Drimys winteri sesquiterpenes correlates with their therapeutic actions.The promiscuous pharmacological profile of Drimys winteri sesquiterpenes suggests they modulate multiple protein targets in vivo,making them potentially useful for treating complex,multifactorial diseases.Further studies at the molecular level may aid in developing multitargeted drugs with enhanced therapeutic effects.
基金supported by JSPS,MEXT,CORE(Center for Optical Research and Education,Utsunomiya University),ASHULA,ILE/Osaka University,and CDI(Cre-ative Department for Innovation,Utsunomiya University).
文摘In this review paper on heavy ion inertial fusion(HIF),the state-of-the-art scientific results are presented and discussed on the HIF physics,including physics of the heavy ion beam(HIB)transport in a fusion reactor,the HIBs-ion illumination on a direct-drive fuel target,the fuel target physics,the uniformity of the HIF target implosion,the smoothing mechanisms of the target implosion non-uniformity and the robust target implosion.The HIB has remarkable preferable features to release the fusion energy in inertial fusion:in particle accelerators HIBs are generated with a high driver efficiency of~30%-40%,and the HIB ions deposit their energy inside of materials.Therefore,a requirement for the fusion target energy gain is relatively low,that would be~50-70 to operate a HIF fusion reactor with the standard energy output of 1 GWof electricity.The HIF reactor operation frequency would be~10-15 Hz or so.Several-MJ HIBs illuminate a fusion fuel target,and the fuel target is imploded to about a thousand times of the solid density.Then the DT fuel is ignited and burned.The HIB ion deposition range is defined by the HIB ions stopping length,which would be~1 mm or so depending on the material.Therefore,a relatively large density-scale length appears in the fuel target material.One of the critical issues in inertial fusion would be a spherically uniform target compression,which would be degraded by a non-uniform implosion.The implosion non-uniformity would be introduced by the Rayleigh-Taylor(R-T)instability,and the large densitygradient-scale length helps to reduce the R-T growth rate.On the other hand,the large scale length of the HIB ions stopping range suggests that the temperature at the energy deposition layer in a HIF target does not reach a very-high temperature:normally about 300 eV or so is realized in the energy absorption region,and that a direct-drive target would be appropriate in HIF.In addition,the HIB accelerators are operated repetitively and stably.The precise control of the HIB axis manipulation is also realized in the HIF accelerator,and the HIB wobbling motion may give another tool to smooth the HIB illumination non-uniformity.The key issues in HIF physics are also discussed and presented in the paper.
基金supported by the National Natural Science Foundation of China,No.31000514the Scientific Research Project for Talent with High Education of Xinxiang Medical University,No.2007502002
文摘The electrophysiological properties of potassium ion channels are regarded as a basic index for determining the functional differentiation of neural stem cells. In this study, neural stem cells from the hippocampus of newborn rats were induced to differentiate with neurotrophic growth factor, and the electrophysiological properties of the voltage-gated potassium ion channels were observed. Immunofluorescence staining showed that the rapidly proliferating neural stem cells formed spheres in vitro that expressed high levels of nestin. The differentiated neurons were shown to express neuron-specific enolase. Flow cytometric analysis revealed that the neural stem cells were actively dividing and the percentage of cells in the S ＋ G2/M phase was high. However, the ratio of cells in the S ＋ G2/M phase decreased obviously as differentiation proceeded. Whole-cell patch-clamp re- cordings revealed apparent changes in potassium ion currents as the neurons differentiated. The potassium ion currents consisted of one transient outward potassium ion current and one delayed rectifier potassium ion current, which were blocked by 4-aminopyridine and tetraethylammonium, respectively. The experimental findings indicate that neural stem cells from newborn rat hippo- campus could be cultured and induced to differentiate into functional neurons under defined condi- tions in vitro. The differentiated neurons expressed two types of outward potassium ion cur＇ents similar to those of mature neurons in vivo.
文摘In this paper, we studied the process of dissociation unimolecular of the evaporation of H+2n+1 hydrogen clusters according to size, using the Rice-Ramsperger-Kassel-Marcus (RRKM) theory. The rate constants k(E) were determined with the use of statistical theory of unimolecular reactions using various approximations. In our work, we used the products frequencies instead of transitions frequencies in the calculation of unimolecular dissociation rates obtained by three models RRKM. The agreement between the experimental cross section ratio and calculated rate ratio with direct count approximation seems to be reasonable.
基金was supported by the U.S.Department of Energy(DOE),Office of Science,Office of Basic Energy Sciences,Division of Chemical Sciences,Geosciences,and Biosciences,Condensed Phase and Interfacial Molecular Science program,FWP 16248.
文摘MgATP is a stable complex formed by the chelation of Mg^(2+)with deprotonated adenosine-5'-triphosphate(ATP).In the cellular environment,MgATP plays a critical role in ATP hydrolysis,releasing substantial energy to support essential biological functions.To understand the structure and stabilization mechanism of MgATP,we conducted a joint negative ion photoelectron spectroscopic and computational study of the[ATP^(4-)·Mg^(2+)]^(2-)complex dianion,using[ATP^(4-)·2H^(+)]^(2-)as a reference.The experimentally determined adiabatic and vertical detachment energies(ADE and VDE)of[ATP^(4-)·Mg^(2+)]^(2-)at 20 K are 3.51±0.05 eV and 3.82±0.05 eV,respectively.The major spectral features of[ATP^(4-)·Mg^(2+)]^(2-)are attributed to two theoretically identified isomers with unfolded geometries,which are stabilized primarily by electrostatic interactions between Mg^(2+)and the triphosphate and ribose groups,with four deprotonated oxygens forming a pseudo-tetrahedral coordination.In contrast,[ATP^(4-)·2H^(+)]^(2-)exhibits a fundamentally different stabilization mechanism.Although most of the fifteen identified[ATP^(4-)·2H^(+)]^(2-)isomers also adopt unfolded geometries,they are primarily stabilized by intramolecular hydrogen bonds within the triphosphate group and between triphosphate and ribose groups.The interaction between ATP^(4-)and two protons is found to be much weaker than that with Mg^(2+),and[ATP^(4-)·2H^(+)]^(2-)exhibits substantial structural flexibility compared to[ATP^(4-)·Mg^(2+)]^(2-)due to the conformational constraint of the triphosphate chain by Mg^(2+).Thirteen[ATP^(4-)·2H^(+)]^(2-)isomers with unfolded geometries likely account for the major high-EBE(electron-binding-energy)spectral features.Notably,for the first time,a low EBE and temperature-dependent spectral feature is observed and attributed to two folded isomers of[ATP^(4-)·2H^(+)]^(2-),which exist at 20 K but disappear at room temperature.This study provides valuable molecular-level insights into cellular MgATP that resides within the hydrophobic pockets of proteins.
基金supported by the Guangdong Major Project of Basic and Applied Basic Research(Grant Nos.2020B0301030008 and 2023A1515010416)the National Natural Science Foundation of China(Grant Nos.12375073,12275091,12147128,and 12035007).
文摘We study the production of the X(6900)in the ultra-peripheral heavy ion collisions at the LHC energy region.The potential quantum numbers of X(6900)could be 0^(±+)and 2^(±+).We find that the transverse momentum and the polar angle distributions of X(6900)can be used to distinguish these four potential quantum numbers.These characteristic distributions originate from linearly polarized photons emitted by relativistic nuclei and can be measured by further LHC experiments.
基金the support of the Romanian Government and the European Union through the European Regional Development Fund–the Competitiveness Operational Programme (1/07.07.2016, COP, Grant ID No. 1334) Phases Ⅱthe Romanian Ministry of Research, Innovation and Digitalization: Program Nucleu Grant No. PN23210105+6 种基金supported by the IOSIN Funds for Research Infrastructures of National Interest funded by the Romanian Ministry of Research, Innovation and Digitalizationsupported by Project No. ELI-RO/DFG/2023_001 ARNPhot funded by the Institute of Atomic Physics (Romania), the European Union, the Romanian Governmentthe Health Program, within the project “Medical Applications of High-Power Lasers–Dr. LASER,” SMIS Code 326475by Grant Nos. ELI-RO/RDI/2024_14 SPARC and ELI-RO/RDI/2024_8 AMAPBMBF Grant No. 05P24PF2 (Germany)the EuroHPC Joint Undertaking for awarding us access to Karolina at IT4Innovations (VAB-TU), Czechia under Project No. EHPCREG-2023R02-006 (Grant No. DD-23-157)Ministry of Education, Youth and Sports of the Czech Republic through e-INFRA CZ (Grant ID No. 90140)
文摘We introduce a scheme aiming at the generation of quasi-monochromatic carbon ion bunches from laser-solid interaction.The proposed scheme is an extension of the“peeler”acceleration originally proposed for proton acceleration,which involves irradiating the narrow(submicrometer)side of a tape target.This results in the generation of a surface plasma wave and the subsequent acceleration of a proton bunch with high peak energy,quasi-monochromaticity,low energy bandwidth,and low divergence by the electrostatic field induced at the target rear.Up to now,the higher-Z(e.g.,carbon)ion bunches obtained with the peeler scheme have been found to exhibit an exponentially decaying thermal-like energy spectrum.To achieve a low energy bandwidth,we place a mass-limited carbon structure at the rear of the target.Using 3D particle-in-cell simulations,we show that a quasi-monochromatic carbon bunch can indeed be obtained.With a multi-PW laser pulse,10^(8) carbon ions with peak energy~110 MeV/u and with a divergence of 20° in the vertical plane and~1° in the horizontal plane can be generated.The quasi-monochromaticity,together with the low duration of the beam and in combination with the versatility of high-power laser facilities,should make this scheme attractive for practical applications such as heavy ion cancer therapy and higher-resolution diagnostics of extreme plasma states.
