Hydrodynamic instability growth at the deuterium-tritium(DT)fuel-ablator interface plays a critical role in determining the performance of inertial confinement fusion implosions.During the late stages of implosion,ins...Hydrodynamic instability growth at the deuterium-tritium(DT)fuel-ablator interface plays a critical role in determining the performance of inertial confinement fusion implosions.During the late stages of implosion,insufficient doping of the ablator material can result in highenergy X-ray preheat,which may trigger the development of a classical-like Rayleigh-Taylor instability(RTI)at the fuel-ablator interface.In implosion experiments at the Shenguang 100 kJ-level laser facility,the primary source of perturbation is the roughness of the inner DT ice interface.In this study,we propose an analytical model to describe the feed-out process of the initial roughness of the inner DT ice interface.The perturbation amplitude derived from this model serves as the initial seed for the late-time RTI during the acceleration phase.Our findings confirm the presence of classical-like RTI at the fuel-ablator interface.Numerical simulations conducted using a radiation hydrodynamic code validate the proposed analytical model and demonstrate the existence of a peak mode number in both the feed-out process and the classical-like RTI.It provides an alternative bridge between the current target fabrication limitations and the unexpected implosion performance.展开更多
The quantum confinement effect fundamentally alters the optical and electronic properties of quantum dots(QDs),making them versatile building blocks for next-generation light-emitting diodes(LEDs).This study investiga...The quantum confinement effect fundamentally alters the optical and electronic properties of quantum dots(QDs),making them versatile building blocks for next-generation light-emitting diodes(LEDs).This study investigates how quantum confinement governs the charge transport,exciton dynamics,and emission efficiency in QD-LEDs,using CsPbI_(3) QDs as a model system.By systematically varying QD sizes,we reveal size-dependent trade-offs in LED performance,such as enhanced efficiency for smaller QDs but increased brightness and stability for larger QDs under high current densities.Our findings offer critical insights into the design of high-performance QD-LEDs,paving the way for scalable and energy-efficient optoelectronic devices.展开更多
Harvesting the immense and renewable osmotic energy with reverse electrodialysis(RED)technology shows great promise in dealing with the ever-growing energy crisis.One key challenge is to improve the output power densi...Harvesting the immense and renewable osmotic energy with reverse electrodialysis(RED)technology shows great promise in dealing with the ever-growing energy crisis.One key challenge is to improve the output power density with improved trade-off between membrane permeability and selectivity.Herein,polyelectrolyte hydrogels(channel width,2.2 nm)with inherent high ion conductivity have been demonstrated to enable excellent selective ion transfer when confined in cylindrical anodized aluminum pore with lateral size even up to the submillimeter scale(radius,0.1 mm).The membrane permeability of the anti-swelling hydrogel can also be further increased with cellulose nanofibers.With real seawater and river water,the output power density of a three-chamber cell on behalf of repeat unit of RED system can reach up to 8.99 W m^(-2)(per unit total membrane area),much better than state-of-the-art membranes.This work provides a new strategy for the preparation of polyelectrolyte hydrogel-based ion-selective membranes,owning broad application prospects in the fields of osmotic energy collection,electrodialysis,flow battery and so on.展开更多
Confinement effect is an effective method to enhance carbon dioxide(CO_(2))solubility.In this study,a hybrid sorbent of 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide([Hmim][NTf_2])/mesoporous titanium ...Confinement effect is an effective method to enhance carbon dioxide(CO_(2))solubility.In this study,a hybrid sorbent of 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide([Hmim][NTf_2])/mesoporous titanium dioxide(M-TiO_(2))/water(H_2O)was developed,and its confinement effect was regulated by changing the pore structure of M-TiO_(2).CO_(2) solubility in the hybrid sorbent was measured experimentally,and the thermodynamic properties including Henry's constant and desorption enthalpy were calculated.Furthermore,the confinement effect in the hybrid sorbent was quantified.Additionally,the hybrid sorbent was recycled with a multi-cycle experiment.The results showed that M-TiO_(2) calcined at 773.2 K(MT500)could lead to an efficient confinement effect.CO_(2) solubility in the hybrid sorbent increased by 49.8%compared to that of H_2O when the mass fraction of[Hmim][NTf_2]/MT500 was 5.0%(mass),where the contribution of confinement effect on Gibbs free energy occupied 5.2%.展开更多
Spatial confinement of block copolymers can induce frustrations,which can further be utilized to regulate self-assembled structures,thus providing an efficient route for fabricating novel structures.We studied the sel...Spatial confinement of block copolymers can induce frustrations,which can further be utilized to regulate self-assembled structures,thus providing an efficient route for fabricating novel structures.We studied the self-assembly of AB di-block copolymers(di-BCPs)confined in Janus spherical nanocavities using simulations,and explained the structure formation mechanisms.In the case of a strongly selective cavity wall,all the lamella-forming,gyroid-forming,and cylinder-forming di-BCPs can form interfacial frustration-induced Janus concentric perforated lamellar nanoparticles,whose outermost is a Janus spherical shell and the internal is a sphere with concentric perforated lamellar structure.In particular,Janus concentric perforated lamellar nanoparticles with holes distributed only near the equatorial plane were obtained in both lamella-forming and gyroid-forming di-BCPs,directly reflecting the effect of interfacial frustration.The minority-block domain of the cylider-forming di-BCPs may form hemispherical perforated lamellar structures with holes distributed in parallel layers with a specific orientation.For symmetric di-BCPs,both the A and B domains in each nanoparticle are continuous,interchangeable,and have rotational symmetry.While for gyroid-forming and cylinder-forming di-BCPs,only the majority-block domains are continuous in each nanoparticle,and holes in the minority-block domains usually have rotational symmetry.In the case of a weakly selective cavity wall,the inhomogeneity of the cavity wall results in structures having a specific orientation(such as flower-like and branched structures in gyroid-forming and cylinder-forming di-BCPs)and a perforated wetting layer with uniformly distributed holes.The novel nanoparticles obtained may have potential applications in nanotechnology as functional nanostructures or nanoparticles.展开更多
We propose an all-optical,single-laser-pulse scheme for generating a dense relativistic strongly magnetized electron-positron pair plasma.The scheme involves the interaction of an extremely intense(I■10^(24) W/cm^(2)...We propose an all-optical,single-laser-pulse scheme for generating a dense relativistic strongly magnetized electron-positron pair plasma.The scheme involves the interaction of an extremely intense(I■10^(24) W/cm^(2))circularly polarized laser pulse with a solid-density target containing a conical cavity.Through full-scale three-dimensional particle-in-cell simulations that account for quantum electrodynamic effects,it is shown that this interaction results in two significant outcomes:first,the generation of quasi-static magnetic fields reaching tens of gigagauss,and,second,the production of large quantities of electron-positron pairs(up to 10^(13))via the Breit-Wheeler process.The e^(-)e^(+)plasma becomes trapped in the magnetic field and remains confined in a small volume for hundreds of femtoseconds,far exceeding the laser timescale.The dependence of pair plasma parameters,as well as the efficiency of plasma production and confinement,is discussed in relation to the properties of the laser pulse and the target.Realizing this scheme experimentally would enable the investigation of physical processes relevant to extreme astrophysical environments.展开更多
Conversion-type anode materials are highly desirable for Na-ion batteries(NIBs)due to their high theoretical capacity.Nevertheless,the active materials undergo severe expansion and pulverization during the sodiation,r...Conversion-type anode materials are highly desirable for Na-ion batteries(NIBs)due to their high theoretical capacity.Nevertheless,the active materials undergo severe expansion and pulverization during the sodiation,resulting in inferior cycling stability.Herein,a self-supporting three-dimensional(3D)graphene sponge decorated with Fe_(2)O_(3)nanocubes(rGO@Fe_(2)O_(3))is constructed.Specifically,the 3D graphene sponge with resilience and high porosity benefits to accommodate the volume expansion of the Fe_(2)O_(3)nanocubes and facilitates the rapid electrons/ions transport,enabling spatial confinement to achieve outstanding results.Besides,the free-standing rGO@Fe_(2)O_(3)can be directly used as an electrode without additional binders and conductive additives,which helps to obtain a higher energy density.Based on the total mass of the rGO@Fe_(2)O_(3)material,the rGO@Fe_(2)O_(3)anode presents a specific capacity of 859 mAh/g at 0.1 A/g.It also delivers an impressive cycling performance(327 mAh/g after 2000 cycles at 1 A/g)and a superior rate capacity(162mAh/g at 20 A/g).The coin-type Na_(3)V_(2)(PO_(4))_(3)@C//rGO@Fe_(2)O_(3)NIB exhibits an energy density of 265.3Wh/kg.This unique 3D ionic/electronic conductive network may provide new strategies to design advanced conversion-type anode materials for high-performance NIBs.展开更多
The effect of drive laser wavelength on the growth of ablative Rayleigh–Taylor instability(ARTI)in inertial confinemen fusion(ICF)is studied with two-dimensional numerical simulations.The results show that in the pla...The effect of drive laser wavelength on the growth of ablative Rayleigh–Taylor instability(ARTI)in inertial confinemen fusion(ICF)is studied with two-dimensional numerical simulations.The results show that in the plasma acceleration phase,shorter wavelengths lead to more efficien coupling between the laser and the kinetic energy of the implosion fluid Under the condition that the laser energy coupled to the implosion flui is constant,the ARTI growth rate decreases as the laser wavelength moves toward the extreme ultraviolet band,reaching its minimum value near λ=65 nm,and when the laser wavelength continuously moves toward the X-ray band,the ARTI growth rate increases rapidly.It is found that the results deviate from the theoretical ARTI growth rate.As the laser intensity benchmark increases,the position of the minimum ARTI growth rate shifts toward shorter wavelengths.As the initial sinusoidal perturbation wavenumber decreases,the position of the minimum ARTI growth rate shifts toward longer wavelengths.We believe that the conclusions drawn from the present simulations and analysis will help provide a better understanding of the ICF process and improve the theory of ARTI growth.展开更多
Ring polymers are ubiquitous in various fields including biomaterials,drug release and gene therapy.All of these applications involve the dynamics and diffusion process of ring polymers in a confined environment.By us...Ring polymers are ubiquitous in various fields including biomaterials,drug release and gene therapy.All of these applications involve the dynamics and diffusion process of ring polymers in a confined environment.By using dynamic light scattering(DLS),we discovered a dynamical transition for charged ring polymers with increasing ring concentration in the gel matrix from a diffusive state to a non-diffusive topological frustrated state with a more compact conformation.When the ring polymer size is smaller than the mesh size of the gel matrix,the rings are diffusive at low concentration of 5 g/L.The ring diffusion coefficient in the gel matrix is an order of magnitude smaller than that of rings in solution,obeying the Ogston's model.At high ring concentration of 40 g/L,the collective dynamical behavior of the charged rings exhibits a topologically frustrated non-diffusive state,which may originate from the inter-ring threading with the external confinement from the gel matrix.Based on our previous theoretical work,we also conjectured that in such a non-diffusive state,the ring polymers might adopt a more compact conformation with the overall size exponentν=1/3.展开更多
In shale reservoirs,fluids are often confined within nanopores,leading to apparent effects on the properties and phase behavior of the fluid.However,previous studies have primarily focused on the effect of capillary p...In shale reservoirs,fluids are often confined within nanopores,leading to apparent effects on the properties and phase behavior of the fluid.However,previous studies have primarily focused on the effect of capillary pressure or adsorption on well performance,and only a very limited number of studies have researched the complex and coupled impact of confinement on capillarity,adsorption,and interactions between fluid molecules and pore walls.Therefore,in this study,an effective method is developed for evaluating the coupled effects of nanopore confinement on CO_(2) injection performance.First,a comprehensive thermodynamic model that incorporates adsorption,capillary pressure,and molecule-wall interaction in nanopores by modifying the Peng-Robinson equation of state(PR-EOS)is proposed.Subsequently,the calculated critical properties of different components are validated against experimental measured data,illustrating that the developed model can accurately predict the properties of the components of CO_(2)-hydrocarbon systems.Numerical simulations of field-scale case studies were then performed and calibrated using a modified phase equilibrium model.Typical fluid properties were inputted to investigate the effect of nanopore confinement on the CO_(2) injection performance.The results of this study show that the ultimate recovery factor increases by approximately 4.61%at a pore size of 10 nm,indicating that nanopore confinement is advantageous to well performance.Light hydrocarbons undergo more intense mass transfer than heavy hydrocarbons.Furthermore,as the pore radius decreased from 100 nm to 10 nm,the CO_(2) storage coefficient increased by 2.8%.The findings of this study deepen the collective understanding of the effect of nanopore confinement on CO_(2) displacement and storage,which has significant field-scale applications.展开更多
Currently,simultaneous regulation of external morphology and internal electronic structure for Na_(3)V_(2)(PO_(4))_(3)(NVP)is rarely realized.Herein,complexes of β-cyclodextrin(βCD)and ethylenediaminetetraacetic aci...Currently,simultaneous regulation of external morphology and internal electronic structure for Na_(3)V_(2)(PO_(4))_(3)(NVP)is rarely realized.Herein,complexes of β-cyclodextrin(βCD)and ethylenediaminetetraacetic acid ferric sodium salt(EDTAFeNa)are utilized for the one-step preparation of NVP with spherical morphology as well as Fe substitution.βCD is initially hydrolyzed into glucose,and then carbon microspheres with numerous pores are formed through continuous dehydration and carbonization.The intermediate hydroxymethylfurfural is rich in active functional groups,which are attractive for the V/P-contained raw materials.Accordingly,the nucleation sites for NVP are successfully limited in the spherical framework,possessing a superior surface area of 97.15 g m^(-2).Furthermore,the beneficial Fe in EDTAFeNa enters into the NVP bulk to construct a novel Fe-doped Na_(3)V_(1.95)Fe_(0.05)(PO_(4))_(3)(NVP/β-ISC)material.Fe-substitution induces significant optimizations of electronic structure for NVP,which has been verified by the newly generated abundant oxygen vacancies and extended V-O bond length.Moreover,a multielectron reaction is activated,resulting from the V^(4+)/V^(5+)redox couple.The charge compensation mechanism of NVP/β-ISC is also deeply investigated.Density functional theory(DFT)calculations theoretically elaborate the mechanism of Fe-doping.Consequently,NVP/β-ISC reveals superior sodium storage performance in both half and full cells and even at different extreme conditions(needling,soaking,bending,and freezing).展开更多
Recently, we reported a series of reversibly interlocked polymer networks(RILNs), whose mechanical robustness and functionalities improvement was believed to be derived from topological interlocking of two sub-network...Recently, we reported a series of reversibly interlocked polymer networks(RILNs), whose mechanical robustness and functionalities improvement was believed to be derived from topological interlocking of two sub-networks, although the direct evidence for the deduction is still lacking. Herein, a specially-designed RILNs system, in which the inter-component hydrogen bonds can be shielded as needed, was prepared and used to study the micro-structures of RILNs, aiming to verify the existence of mechanical interlocking in RILNs. By changing the pH of the swelling solvent, the effect exerted by the inter-component non-covalent bonds was eliminated, so detailed information of the networks structure was exposed. The small angle X-ray scattering(SAXS) and small-angle neutron scattering(SANS) results indicated that swelling-induced structural evolution of the two sub-networks mutually affected each other, even when the inter-component hydrogen bonds were absent, proving the presence of topological interlocking. The findings may help to draw a more accurate physical image and reveal the detailed structureproperty relationship of RILNs.展开更多
The redox couple of I^(0)/I^(-)in aqueous rechargeable iodine–zinc(I^(2)-Zn)batteries is a promising energy storage resource since it is safe and cost-effective,and provides steady output voltage.However,the cycle li...The redox couple of I^(0)/I^(-)in aqueous rechargeable iodine–zinc(I^(2)-Zn)batteries is a promising energy storage resource since it is safe and cost-effective,and provides steady output voltage.However,the cycle life and efficiency of these batteries remain unsatisfactory due to the uncontrolled shuttling of polyiodide(I_(3)^(-)and I_(5)^(-))and side reactions on the Zn anode.Starch is a very low-cost and widely sourced food used daily around the world.“Starch turns blue when it encounters iodine”is a classic chemical reaction,which results from the unique structure of the helix starch molecule–iodine complex.Inspired by this,we employ starch to confine the shuttling of polyiodide,and thus,the I^(0)/I^(-)conversion efficiency of an I^(2)-Zn battery is clearly enhanced.According to the detailed characterizations and theoretical DFT calculation results,the enhancement of I^(0)/I^(-)conversion efficiency is mainly originated from the strong bonding between the charged products of I_(3)^(-)and I_(5)^(-)and the rich hydroxyl groups in starch.This work provides inspiration for the rational design of high-performance and low-cost I^(2)-Zn in AZIBs.展开更多
The supramolecular F?rster resonance energy transfer(FRET)is seen as a promising approach for organic photocatalysis using dyes as catalysts,because it combines the high efficiency of energy transfer with the dynamic ...The supramolecular F?rster resonance energy transfer(FRET)is seen as a promising approach for organic photocatalysis using dyes as catalysts,because it combines the high efficiency of energy transfer with the dynamic responsiveness based on non-covalent interactions.Here we propose a supramolecular FRET photocatalysis strategy forα-oxyamination reaction based on supramolecular confinement effect.The well-designed benzothiadiazole-based cationic monomer as energy donor and the dyes of Nile Red as acceptor are doped into the amphiphilic surfactants of sodium dodecyl sulfate(SDS).Benefitting from the supramolecular confinement space provided by SDS in aqueous environment,the FRET process between the monomer and Nile Red is effectively achieved(exciton migration rate:3.99×10^(14)L mol^(-1)s^(-1)).On this basis,the supramolecular FRET system is used as an efficient energy source to catalyzeα-oxyamination reactions between a series of 1,3-dicarbonyl compounds and 2,2,6,6-tetramethylpiperidine-1-oxyl under white LED light,showing a yield as high as 94%and a turnover frequency value of 3.92 h^(-1).This photocatalytic result shows a great enhancement compared to that of Nile Red alone.展开更多
Natural enzymes,such as horseradish peroxidase(HRP),are a class of important biocatalysts with the high specificity,but their catalytic efficiency is usually unsatisfactory.Thus,the higher catalytic efficiency induced...Natural enzymes,such as horseradish peroxidase(HRP),are a class of important biocatalysts with the high specificity,but their catalytic efficiency is usually unsatisfactory.Thus,the higher catalytic efficiency induced by the confinement effect is promising in optical sensing systems.In this work,a dark-field light scattering sensing platform was fabricated by the confinement effect of HRP from hybridization chain reaction(HCR)and then released to solution by the toehold-mediated strand displacement reaction(TSDR).Then,HRP catalyzed the 3,3,5,5-tetramethylbenzidine(TMB)to TMB^(2+)with the assistance of hydrogen peroxide,which etched the gold nanorods(Au NRs)with the weakened light scattering.The single-particle assay was established based on the decreased light scattering intensity of AuNRs under dark-field microscope.The proposed assay revealed excellent analytical performance within a linear range from 25 pmol/L to 600 pmol/L,and a low limit of detection of 3.12 pmol/L.Additionally,it also manifested satisfactory recovery of mi RNA-21 in human serum samples.The high sensitivity,excellent specificity,and universal applicability make this sensing platform promising for disease diagnosis.展开更多
The emergence of Li–Mg hybrid batteries has been receiving attention,owing to their enhanced electrochemical kinetics and reduced overpotential.Nevertheless,the persistent challenge of uneven Mg electrodeposition rem...The emergence of Li–Mg hybrid batteries has been receiving attention,owing to their enhanced electrochemical kinetics and reduced overpotential.Nevertheless,the persistent challenge of uneven Mg electrodeposition remains a significant impediment to their practical integration.Herein,we developed an ingenious approach that centered around epitaxial electrocrystallization and meticulously controlled growth of magnesium crystals on a specialized MgMOF substrate.The chosen MgMOF substrate demonstrated a robust affinity for magnesium and showed minimal lattice misfit with Mg,establishing the crucial prerequisites for successful heteroepitaxial electrocrystallization.Moreover,the incorporation of periodic electric fields and successive nanochannels within the MgMOF structure created a spatially confined environment that considerably promoted uniform magnesium nucleation at the molecular scale.Taking inspiration from the“blockchain”concept prevalent in the realm of big data,we seamlessly integrated a conductive polypyrrole framework,acting as a connecting“chain,”to interlink the“blocks”comprising the MgMOF cavities.This innovative design significantly amplified charge‐transfer efficiency,thereby increasing overall electrochemical kinetics.The resulting architecture(MgMOF@PPy@CC)served as an exceptional host for heteroepitaxial Mg electrodeposition,showcasing remarkable electrostripping/plating kinetics and excellent cycling performance.Surprisingly,a symmetrical cell incorporating the MgMOF@PPy@CC electrode demonstrated impressive stability even under ultrahigh current density conditions(10mAcm^(–2)),maintaining operation for an extended 1200 h,surpassing previously reported benchmarks.Significantly,on coupling the MgMOF@PPy@CC anode with a Mo_(6)S_(8) cathode,the assembled battery showed an extended lifespan of 10,000 cycles at 70 C,with an outstanding capacity retention of 96.23%.This study provides a fresh perspective on the rational design of epitaxial electrocrystallization driven by metal–organic framework(MOF)substrates,paving the way toward the advancement of cuttingedge batteries.展开更多
The molybdenum carbide(Mo_(2)C)has been regarded as one of the most cost-efficient and stable electrocatalyst for the hydrogen evolution reaction(HER)by the virtue of its Pt-like electronic structures.However,the inhe...The molybdenum carbide(Mo_(2)C)has been regarded as one of the most cost-efficient and stable electrocatalyst for the hydrogen evolution reaction(HER)by the virtue of its Pt-like electronic structures.However,the inherent limitation of high density of empty valence band significantly reduces its catalytic reactivity by reason of strong hydrogen desorption resistance.Herein,we propose a multiscale confinement synthesis method to design the nitrogen-rich Mo_(2)C for modulating the band structure via decomposing the pre-coordination bonded polymer in a pressure-tight tube sealing system.Pre-bonded c/N-Mo in the coordination precursor constructs a micro-confinement space,enabling the homogeneous nitrogenization in-situ happened during the formation of Mo_(2)C.Simultaneously,the evolved gases from the precursor decomposition in tube sealing system establish a macro-confinement environment,preventing the lattice N escape and further endowing a continuous nitridation.Combining the multiscale confinement effects,the nitrogen-rich Mo2C displays as high as 25%N-Mo concentration in carbide lattice,leading to a satisfactory band structure.Accordingly,the constructed nitrogen-rich Mo_(2)C reveals an adorable catalytic activity for HER in both alkaline and acid solution.It is anticipated that the multiscale confinement synthesis strategy presents guideline for the rational design of electrocatalysts and beyond.展开更多
Quantum confinement is recognized to be an inherent property in low-dimensional structures.Traditionally,it is believed that the carriers trapped within the well cannot escape due to the discrete energy levels.However...Quantum confinement is recognized to be an inherent property in low-dimensional structures.Traditionally,it is believed that the carriers trapped within the well cannot escape due to the discrete energy levels.However,our previous research has revealed efficient carrier escape in low-dimensional structures,contradicting this conventional understanding.In this study,we review the energy band structure of quantum wells along the growth direction considering it as a superposition of the bulk material dispersion and quantization energy dispersion resulting from the quantum confinement across the whole Brillouin zone.By accounting for all wave vectors,we obtain a certain distribution of carrier energy at each quantized energy level,giving rise to the energy subbands.These results enable carriers to escape from the well under the influence of an electric field.Additionally,we have compiled a comprehensive summary of various energy band scenarios in quantum well structures relevant to carrier transport.Such a new interpretation holds significant value in deepening our comprehension of low-dimensional energy bands,discovering new physical phenomena,and designing novel devices with superior performance.展开更多
ICF(inertial confinement fusion)holds significant potential for achieving controlled nuclear fusion,but challenges related to efficient energy transfer and plasma stabilization remains.This article explores the ion-bu...ICF(inertial confinement fusion)holds significant potential for achieving controlled nuclear fusion,but challenges related to efficient energy transfer and plasma stabilization remains.This article explores the ion-bubble trigger mechanism as a promising solution for improving the compression and energy deposition processes in ICF,particularly when coupled with external magnetic fields,wigglers,undulators,and trapped magnetic fields.The ion-bubble mechanism enhances energy transfer by creating localized heating in the plasma,increasing the likelihood of fusion ignition.External magnetic fields,through their interaction with plasma particles,can optimize ion-bubble interactions by influencing particle trajectories and stabilizing plasma instabilities.Additionally,wigglers and undulators—devices that create oscillating magnetic fields—offer a means to fine-tune the interaction between plasma and electromagnetic radiation,further enhancing the ion-bubble effect.Trapped magnetic fields,formed through plasma compression,also contribute to plasma confinement and stability,offering further support for the ion-bubble trigger mechanism.By combining these factors,the ion-bubble trigger mechanism in ICF could significantly improve fusion efficiency and bring us closer to realizing sustainable fusion energy.展开更多
A Si p-π-n diode with β-FeSi 2 particles embedded in the unintentionally doped Si (p--type) was designed for determining the band offset at β-FeSi 2-Si heterojunction.When the diode is under forward bias,the elec...A Si p-π-n diode with β-FeSi 2 particles embedded in the unintentionally doped Si (p--type) was designed for determining the band offset at β-FeSi 2-Si heterojunction.When the diode is under forward bias,the electrons injected via the Si n-p- junction diffuse to and are confined in the β-FeSi 2 particles due to the band offset.The storage charge at the β-FeSi 2-Si heterojunction inversely hamper the further diffusion of electrons,giving rise to the localization of electrons in the p--Si near the Si junction,which prevents them from nonradiative recombination channels.This results in electroluminescence (EL) intensity from both Si and β-FeSi 2 quenching slowly up to room temperature.The temperature dependent ratio of EL intensity of β-FeSi 2 to Si indicates the loss of electron confinement following thermal excitation model.The conduction band offset between Si and β-FeSi 2 is determined to be about 0 2eV.展开更多
基金funded by the National Key R&D Program of China(Grant No.2023YFA1608400)the National Natural Science Foundation of China(Grant No.12302281).
文摘Hydrodynamic instability growth at the deuterium-tritium(DT)fuel-ablator interface plays a critical role in determining the performance of inertial confinement fusion implosions.During the late stages of implosion,insufficient doping of the ablator material can result in highenergy X-ray preheat,which may trigger the development of a classical-like Rayleigh-Taylor instability(RTI)at the fuel-ablator interface.In implosion experiments at the Shenguang 100 kJ-level laser facility,the primary source of perturbation is the roughness of the inner DT ice interface.In this study,we propose an analytical model to describe the feed-out process of the initial roughness of the inner DT ice interface.The perturbation amplitude derived from this model serves as the initial seed for the late-time RTI during the acceleration phase.Our findings confirm the presence of classical-like RTI at the fuel-ablator interface.Numerical simulations conducted using a radiation hydrodynamic code validate the proposed analytical model and demonstrate the existence of a peak mode number in both the feed-out process and the classical-like RTI.It provides an alternative bridge between the current target fabrication limitations and the unexpected implosion performance.
基金support from the National Key Research and Development Program of China(2024YFA1207700)National Natural Science Foundation of China(52072141,52102170).
文摘The quantum confinement effect fundamentally alters the optical and electronic properties of quantum dots(QDs),making them versatile building blocks for next-generation light-emitting diodes(LEDs).This study investigates how quantum confinement governs the charge transport,exciton dynamics,and emission efficiency in QD-LEDs,using CsPbI_(3) QDs as a model system.By systematically varying QD sizes,we reveal size-dependent trade-offs in LED performance,such as enhanced efficiency for smaller QDs but increased brightness and stability for larger QDs under high current densities.Our findings offer critical insights into the design of high-performance QD-LEDs,paving the way for scalable and energy-efficient optoelectronic devices.
基金supported by The Project of“20 Items of University”of Jinan(Grant No.202228078)Innovative Research Team in Higher Educational Institutions of Shandong Province(Grant No.2023KJ107)+2 种基金Taishan Scholars Program of Shandong Province(tsqn201812085)National Natural Science Foundation of China(Grant No.51903102,Grant No.52376063,Grant No.52302256)China Postdoctoral Science Foundation(Grant No.2023MD744223).
文摘Harvesting the immense and renewable osmotic energy with reverse electrodialysis(RED)technology shows great promise in dealing with the ever-growing energy crisis.One key challenge is to improve the output power density with improved trade-off between membrane permeability and selectivity.Herein,polyelectrolyte hydrogels(channel width,2.2 nm)with inherent high ion conductivity have been demonstrated to enable excellent selective ion transfer when confined in cylindrical anodized aluminum pore with lateral size even up to the submillimeter scale(radius,0.1 mm).The membrane permeability of the anti-swelling hydrogel can also be further increased with cellulose nanofibers.With real seawater and river water,the output power density of a three-chamber cell on behalf of repeat unit of RED system can reach up to 8.99 W m^(-2)(per unit total membrane area),much better than state-of-the-art membranes.This work provides a new strategy for the preparation of polyelectrolyte hydrogel-based ion-selective membranes,owning broad application prospects in the fields of osmotic energy collection,electrodialysis,flow battery and so on.
基金the National Natural Science Foundation of China(22108115,22478415,and 21978134)Natural Science Foundation of Jiangsu Province(BK20241744)。
文摘Confinement effect is an effective method to enhance carbon dioxide(CO_(2))solubility.In this study,a hybrid sorbent of 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide([Hmim][NTf_2])/mesoporous titanium dioxide(M-TiO_(2))/water(H_2O)was developed,and its confinement effect was regulated by changing the pore structure of M-TiO_(2).CO_(2) solubility in the hybrid sorbent was measured experimentally,and the thermodynamic properties including Henry's constant and desorption enthalpy were calculated.Furthermore,the confinement effect in the hybrid sorbent was quantified.Additionally,the hybrid sorbent was recycled with a multi-cycle experiment.The results showed that M-TiO_(2) calcined at 773.2 K(MT500)could lead to an efficient confinement effect.CO_(2) solubility in the hybrid sorbent increased by 49.8%compared to that of H_2O when the mass fraction of[Hmim][NTf_2]/MT500 was 5.0%(mass),where the contribution of confinement effect on Gibbs free energy occupied 5.2%.
基金supported by the National Natural Science Foundation of China(NSFC)(Nos.22173051,21829301,21774066)College Discipline Innovation and Intelligence Introduction Program(111 Project(B16027)+1 种基金the International Cooperation Base(2016D01025)Tianjin International Joint Research and Development Center。
文摘Spatial confinement of block copolymers can induce frustrations,which can further be utilized to regulate self-assembled structures,thus providing an efficient route for fabricating novel structures.We studied the self-assembly of AB di-block copolymers(di-BCPs)confined in Janus spherical nanocavities using simulations,and explained the structure formation mechanisms.In the case of a strongly selective cavity wall,all the lamella-forming,gyroid-forming,and cylinder-forming di-BCPs can form interfacial frustration-induced Janus concentric perforated lamellar nanoparticles,whose outermost is a Janus spherical shell and the internal is a sphere with concentric perforated lamellar structure.In particular,Janus concentric perforated lamellar nanoparticles with holes distributed only near the equatorial plane were obtained in both lamella-forming and gyroid-forming di-BCPs,directly reflecting the effect of interfacial frustration.The minority-block domain of the cylider-forming di-BCPs may form hemispherical perforated lamellar structures with holes distributed in parallel layers with a specific orientation.For symmetric di-BCPs,both the A and B domains in each nanoparticle are continuous,interchangeable,and have rotational symmetry.While for gyroid-forming and cylinder-forming di-BCPs,only the majority-block domains are continuous in each nanoparticle,and holes in the minority-block domains usually have rotational symmetry.In the case of a weakly selective cavity wall,the inhomogeneity of the cavity wall results in structures having a specific orientation(such as flower-like and branched structures in gyroid-forming and cylinder-forming di-BCPs)and a perforated wetting layer with uniformly distributed holes.The novel nanoparticles obtained may have potential applications in nanotechnology as functional nanostructures or nanoparticles.
基金supported by BMBF-Project No.05P24PF1DFG Project No.PU 213/6-3.
文摘We propose an all-optical,single-laser-pulse scheme for generating a dense relativistic strongly magnetized electron-positron pair plasma.The scheme involves the interaction of an extremely intense(I■10^(24) W/cm^(2))circularly polarized laser pulse with a solid-density target containing a conical cavity.Through full-scale three-dimensional particle-in-cell simulations that account for quantum electrodynamic effects,it is shown that this interaction results in two significant outcomes:first,the generation of quasi-static magnetic fields reaching tens of gigagauss,and,second,the production of large quantities of electron-positron pairs(up to 10^(13))via the Breit-Wheeler process.The e^(-)e^(+)plasma becomes trapped in the magnetic field and remains confined in a small volume for hundreds of femtoseconds,far exceeding the laser timescale.The dependence of pair plasma parameters,as well as the efficiency of plasma production and confinement,is discussed in relation to the properties of the laser pulse and the target.Realizing this scheme experimentally would enable the investigation of physical processes relevant to extreme astrophysical environments.
基金supported by National Natural Science Foundation of China(Nos.52307239,52102300,52207234)the Natural Science Foundation of Hubei Province(Nos.2022CFB1003,2021CFA025).
文摘Conversion-type anode materials are highly desirable for Na-ion batteries(NIBs)due to their high theoretical capacity.Nevertheless,the active materials undergo severe expansion and pulverization during the sodiation,resulting in inferior cycling stability.Herein,a self-supporting three-dimensional(3D)graphene sponge decorated with Fe_(2)O_(3)nanocubes(rGO@Fe_(2)O_(3))is constructed.Specifically,the 3D graphene sponge with resilience and high porosity benefits to accommodate the volume expansion of the Fe_(2)O_(3)nanocubes and facilitates the rapid electrons/ions transport,enabling spatial confinement to achieve outstanding results.Besides,the free-standing rGO@Fe_(2)O_(3)can be directly used as an electrode without additional binders and conductive additives,which helps to obtain a higher energy density.Based on the total mass of the rGO@Fe_(2)O_(3)material,the rGO@Fe_(2)O_(3)anode presents a specific capacity of 859 mAh/g at 0.1 A/g.It also delivers an impressive cycling performance(327 mAh/g after 2000 cycles at 1 A/g)and a superior rate capacity(162mAh/g at 20 A/g).The coin-type Na_(3)V_(2)(PO_(4))_(3)@C//rGO@Fe_(2)O_(3)NIB exhibits an energy density of 265.3Wh/kg.This unique 3D ionic/electronic conductive network may provide new strategies to design advanced conversion-type anode materials for high-performance NIBs.
基金supported by the National Natural Science Foundation of China(NSFC)(Grant Nos.12074399,12204500,and 12004403)the Key Projects of the Intergovernmental International Scientifi and Technological Innovation Cooperation(Grant No.2021YFE0116700)+1 种基金the Shanghai Natural Science Foundation(Grant No.20ZR1464400)the Shanghai Sailing Program(Grant No.22YF1455300)。
文摘The effect of drive laser wavelength on the growth of ablative Rayleigh–Taylor instability(ARTI)in inertial confinemen fusion(ICF)is studied with two-dimensional numerical simulations.The results show that in the plasma acceleration phase,shorter wavelengths lead to more efficien coupling between the laser and the kinetic energy of the implosion fluid Under the condition that the laser energy coupled to the implosion flui is constant,the ARTI growth rate decreases as the laser wavelength moves toward the extreme ultraviolet band,reaching its minimum value near λ=65 nm,and when the laser wavelength continuously moves toward the X-ray band,the ARTI growth rate increases rapidly.It is found that the results deviate from the theoretical ARTI growth rate.As the laser intensity benchmark increases,the position of the minimum ARTI growth rate shifts toward shorter wavelengths.As the initial sinusoidal perturbation wavenumber decreases,the position of the minimum ARTI growth rate shifts toward longer wavelengths.We believe that the conclusions drawn from the present simulations and analysis will help provide a better understanding of the ICF process and improve the theory of ARTI growth.
基金supported by the National Natural Science Foundation of China(No.22273114)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB0770101)+1 种基金the National Key R&D Program of China(No.2023YFE0124500),the National Key R&D Program of China(No.2023YFC2411203)International Partnership Program of the Chinese Academy of Sciences(No.027GJHZ2022061FN)。
文摘Ring polymers are ubiquitous in various fields including biomaterials,drug release and gene therapy.All of these applications involve the dynamics and diffusion process of ring polymers in a confined environment.By using dynamic light scattering(DLS),we discovered a dynamical transition for charged ring polymers with increasing ring concentration in the gel matrix from a diffusive state to a non-diffusive topological frustrated state with a more compact conformation.When the ring polymer size is smaller than the mesh size of the gel matrix,the rings are diffusive at low concentration of 5 g/L.The ring diffusion coefficient in the gel matrix is an order of magnitude smaller than that of rings in solution,obeying the Ogston's model.At high ring concentration of 40 g/L,the collective dynamical behavior of the charged rings exhibits a topologically frustrated non-diffusive state,which may originate from the inter-ring threading with the external confinement from the gel matrix.Based on our previous theoretical work,we also conjectured that in such a non-diffusive state,the ring polymers might adopt a more compact conformation with the overall size exponentν=1/3.
基金supported by National Natural Science Foundation of China(Nos.52474052 and 52074248)Young Elite Scientists Sponsorship Program by Beijing Association for Science and Technology,China(No.BYESS2023414)Scientific Research Innovation Capability Support Project for Young Faculty,China(No.ZYGXQNJSKYCXNLZCXM-E14).
文摘In shale reservoirs,fluids are often confined within nanopores,leading to apparent effects on the properties and phase behavior of the fluid.However,previous studies have primarily focused on the effect of capillary pressure or adsorption on well performance,and only a very limited number of studies have researched the complex and coupled impact of confinement on capillarity,adsorption,and interactions between fluid molecules and pore walls.Therefore,in this study,an effective method is developed for evaluating the coupled effects of nanopore confinement on CO_(2) injection performance.First,a comprehensive thermodynamic model that incorporates adsorption,capillary pressure,and molecule-wall interaction in nanopores by modifying the Peng-Robinson equation of state(PR-EOS)is proposed.Subsequently,the calculated critical properties of different components are validated against experimental measured data,illustrating that the developed model can accurately predict the properties of the components of CO_(2)-hydrocarbon systems.Numerical simulations of field-scale case studies were then performed and calibrated using a modified phase equilibrium model.Typical fluid properties were inputted to investigate the effect of nanopore confinement on the CO_(2) injection performance.The results of this study show that the ultimate recovery factor increases by approximately 4.61%at a pore size of 10 nm,indicating that nanopore confinement is advantageous to well performance.Light hydrocarbons undergo more intense mass transfer than heavy hydrocarbons.Furthermore,as the pore radius decreased from 100 nm to 10 nm,the CO_(2) storage coefficient increased by 2.8%.The findings of this study deepen the collective understanding of the effect of nanopore confinement on CO_(2) displacement and storage,which has significant field-scale applications.
基金financially supported by the Key Research and Development(R&D)Projects of Shanxi Province(202202040201005)the Graduate Innovation Project of Shanxi Province(No.2024SJ261)。
文摘Currently,simultaneous regulation of external morphology and internal electronic structure for Na_(3)V_(2)(PO_(4))_(3)(NVP)is rarely realized.Herein,complexes of β-cyclodextrin(βCD)and ethylenediaminetetraacetic acid ferric sodium salt(EDTAFeNa)are utilized for the one-step preparation of NVP with spherical morphology as well as Fe substitution.βCD is initially hydrolyzed into glucose,and then carbon microspheres with numerous pores are formed through continuous dehydration and carbonization.The intermediate hydroxymethylfurfural is rich in active functional groups,which are attractive for the V/P-contained raw materials.Accordingly,the nucleation sites for NVP are successfully limited in the spherical framework,possessing a superior surface area of 97.15 g m^(-2).Furthermore,the beneficial Fe in EDTAFeNa enters into the NVP bulk to construct a novel Fe-doped Na_(3)V_(1.95)Fe_(0.05)(PO_(4))_(3)(NVP/β-ISC)material.Fe-substitution induces significant optimizations of electronic structure for NVP,which has been verified by the newly generated abundant oxygen vacancies and extended V-O bond length.Moreover,a multielectron reaction is activated,resulting from the V^(4+)/V^(5+)redox couple.The charge compensation mechanism of NVP/β-ISC is also deeply investigated.Density functional theory(DFT)calculations theoretically elaborate the mechanism of Fe-doping.Consequently,NVP/β-ISC reveals superior sodium storage performance in both half and full cells and even at different extreme conditions(needling,soaking,bending,and freezing).
基金financially supported by the National Natural Science Foundation of China (Nos. 52033011, 52173092 and 51973237)Natural Science Foundation of Guangdong Province(Nos. 2019B1515120038, 2020A1515011276 and 2021A1515010417)+4 种基金Science and Technology Planning Project of Guangzhou City (No. 202201011568)the Talented Program of Guizhou University (No. X2022008)Fundamental Research Funds for the Central Universities,Sun Yat-sen University (No. 23yxqntd002)GBRCE for Functional Molecular Engineering,the Youth Innovation Promotion Association,CAS(No. 2020010)Guangdong Basic and Applied Basic Research Foundation (No. 2021A1515110908)。
文摘Recently, we reported a series of reversibly interlocked polymer networks(RILNs), whose mechanical robustness and functionalities improvement was believed to be derived from topological interlocking of two sub-networks, although the direct evidence for the deduction is still lacking. Herein, a specially-designed RILNs system, in which the inter-component hydrogen bonds can be shielded as needed, was prepared and used to study the micro-structures of RILNs, aiming to verify the existence of mechanical interlocking in RILNs. By changing the pH of the swelling solvent, the effect exerted by the inter-component non-covalent bonds was eliminated, so detailed information of the networks structure was exposed. The small angle X-ray scattering(SAXS) and small-angle neutron scattering(SANS) results indicated that swelling-induced structural evolution of the two sub-networks mutually affected each other, even when the inter-component hydrogen bonds were absent, proving the presence of topological interlocking. The findings may help to draw a more accurate physical image and reveal the detailed structureproperty relationship of RILNs.
基金financially supported by the National Natural Science Foundation of China(Nos.U20A20246 and 51872108)the Fundamental Research Funds for the Central Universitiesthe Advanced Talents Incubation Program of Hebei University(521100221039)
文摘The redox couple of I^(0)/I^(-)in aqueous rechargeable iodine–zinc(I^(2)-Zn)batteries is a promising energy storage resource since it is safe and cost-effective,and provides steady output voltage.However,the cycle life and efficiency of these batteries remain unsatisfactory due to the uncontrolled shuttling of polyiodide(I_(3)^(-)and I_(5)^(-))and side reactions on the Zn anode.Starch is a very low-cost and widely sourced food used daily around the world.“Starch turns blue when it encounters iodine”is a classic chemical reaction,which results from the unique structure of the helix starch molecule–iodine complex.Inspired by this,we employ starch to confine the shuttling of polyiodide,and thus,the I^(0)/I^(-)conversion efficiency of an I^(2)-Zn battery is clearly enhanced.According to the detailed characterizations and theoretical DFT calculation results,the enhancement of I^(0)/I^(-)conversion efficiency is mainly originated from the strong bonding between the charged products of I_(3)^(-)and I_(5)^(-)and the rich hydroxyl groups in starch.This work provides inspiration for the rational design of high-performance and low-cost I^(2)-Zn in AZIBs.
基金financially supported by the National Natural Science Foundation of China (Nos.22371230,22022107,22001213,and 22071197)the Postdoctoral Science Foundation of China (Nos.2023M732855,2022TQ0258)the Shaanxi Fundamental Science Research Project for Chemistry & Biology (No.22JHQ020)。
文摘The supramolecular F?rster resonance energy transfer(FRET)is seen as a promising approach for organic photocatalysis using dyes as catalysts,because it combines the high efficiency of energy transfer with the dynamic responsiveness based on non-covalent interactions.Here we propose a supramolecular FRET photocatalysis strategy forα-oxyamination reaction based on supramolecular confinement effect.The well-designed benzothiadiazole-based cationic monomer as energy donor and the dyes of Nile Red as acceptor are doped into the amphiphilic surfactants of sodium dodecyl sulfate(SDS).Benefitting from the supramolecular confinement space provided by SDS in aqueous environment,the FRET process between the monomer and Nile Red is effectively achieved(exciton migration rate:3.99×10^(14)L mol^(-1)s^(-1)).On this basis,the supramolecular FRET system is used as an efficient energy source to catalyzeα-oxyamination reactions between a series of 1,3-dicarbonyl compounds and 2,2,6,6-tetramethylpiperidine-1-oxyl under white LED light,showing a yield as high as 94%and a turnover frequency value of 3.92 h^(-1).This photocatalytic result shows a great enhancement compared to that of Nile Red alone.
基金financial supported from the National Natural Science Foundation of China(No.22174115)the Graduate Education and Teaching Reform Research Project of Chongqing(No.yjg223038)the Fundamental Research Funds for the Central Universities(No.SWU-XDJH202321)。
文摘Natural enzymes,such as horseradish peroxidase(HRP),are a class of important biocatalysts with the high specificity,but their catalytic efficiency is usually unsatisfactory.Thus,the higher catalytic efficiency induced by the confinement effect is promising in optical sensing systems.In this work,a dark-field light scattering sensing platform was fabricated by the confinement effect of HRP from hybridization chain reaction(HCR)and then released to solution by the toehold-mediated strand displacement reaction(TSDR).Then,HRP catalyzed the 3,3,5,5-tetramethylbenzidine(TMB)to TMB^(2+)with the assistance of hydrogen peroxide,which etched the gold nanorods(Au NRs)with the weakened light scattering.The single-particle assay was established based on the decreased light scattering intensity of AuNRs under dark-field microscope.The proposed assay revealed excellent analytical performance within a linear range from 25 pmol/L to 600 pmol/L,and a low limit of detection of 3.12 pmol/L.Additionally,it also manifested satisfactory recovery of mi RNA-21 in human serum samples.The high sensitivity,excellent specificity,and universal applicability make this sensing platform promising for disease diagnosis.
基金National Natural Science Foundation of China,Grant/Award Number:31770608Postgraduate Research&Practice Innovation Program of Jiangsu Province,Grant/Award Number:KYCX22_1081Jiangsu Specially‐appointed Professorship Program,Grant/Award Number:Sujiaoshi[2016]20。
文摘The emergence of Li–Mg hybrid batteries has been receiving attention,owing to their enhanced electrochemical kinetics and reduced overpotential.Nevertheless,the persistent challenge of uneven Mg electrodeposition remains a significant impediment to their practical integration.Herein,we developed an ingenious approach that centered around epitaxial electrocrystallization and meticulously controlled growth of magnesium crystals on a specialized MgMOF substrate.The chosen MgMOF substrate demonstrated a robust affinity for magnesium and showed minimal lattice misfit with Mg,establishing the crucial prerequisites for successful heteroepitaxial electrocrystallization.Moreover,the incorporation of periodic electric fields and successive nanochannels within the MgMOF structure created a spatially confined environment that considerably promoted uniform magnesium nucleation at the molecular scale.Taking inspiration from the“blockchain”concept prevalent in the realm of big data,we seamlessly integrated a conductive polypyrrole framework,acting as a connecting“chain,”to interlink the“blocks”comprising the MgMOF cavities.This innovative design significantly amplified charge‐transfer efficiency,thereby increasing overall electrochemical kinetics.The resulting architecture(MgMOF@PPy@CC)served as an exceptional host for heteroepitaxial Mg electrodeposition,showcasing remarkable electrostripping/plating kinetics and excellent cycling performance.Surprisingly,a symmetrical cell incorporating the MgMOF@PPy@CC electrode demonstrated impressive stability even under ultrahigh current density conditions(10mAcm^(–2)),maintaining operation for an extended 1200 h,surpassing previously reported benchmarks.Significantly,on coupling the MgMOF@PPy@CC anode with a Mo_(6)S_(8) cathode,the assembled battery showed an extended lifespan of 10,000 cycles at 70 C,with an outstanding capacity retention of 96.23%.This study provides a fresh perspective on the rational design of epitaxial electrocrystallization driven by metal–organic framework(MOF)substrates,paving the way toward the advancement of cuttingedge batteries.
基金supported by the National Natural Science Foundation of China(52372201,52125202,52202247)the Natural Science Foundation of Jiangsu Province(1192261031693)the Fundamental Research Funds for the Central Universities(30919011110,1191030558)。
文摘The molybdenum carbide(Mo_(2)C)has been regarded as one of the most cost-efficient and stable electrocatalyst for the hydrogen evolution reaction(HER)by the virtue of its Pt-like electronic structures.However,the inherent limitation of high density of empty valence band significantly reduces its catalytic reactivity by reason of strong hydrogen desorption resistance.Herein,we propose a multiscale confinement synthesis method to design the nitrogen-rich Mo_(2)C for modulating the band structure via decomposing the pre-coordination bonded polymer in a pressure-tight tube sealing system.Pre-bonded c/N-Mo in the coordination precursor constructs a micro-confinement space,enabling the homogeneous nitrogenization in-situ happened during the formation of Mo_(2)C.Simultaneously,the evolved gases from the precursor decomposition in tube sealing system establish a macro-confinement environment,preventing the lattice N escape and further endowing a continuous nitridation.Combining the multiscale confinement effects,the nitrogen-rich Mo2C displays as high as 25%N-Mo concentration in carbide lattice,leading to a satisfactory band structure.Accordingly,the constructed nitrogen-rich Mo_(2)C reveals an adorable catalytic activity for HER in both alkaline and acid solution.It is anticipated that the multiscale confinement synthesis strategy presents guideline for the rational design of electrocatalysts and beyond.
基金the National Natural Science Foundation of China(Grant Nos.61991441 and 62004218)the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDB01000000)Youth Innovation Promotion Association of Chinese Academy of Sciences(Grant No.2021005).
文摘Quantum confinement is recognized to be an inherent property in low-dimensional structures.Traditionally,it is believed that the carriers trapped within the well cannot escape due to the discrete energy levels.However,our previous research has revealed efficient carrier escape in low-dimensional structures,contradicting this conventional understanding.In this study,we review the energy band structure of quantum wells along the growth direction considering it as a superposition of the bulk material dispersion and quantization energy dispersion resulting from the quantum confinement across the whole Brillouin zone.By accounting for all wave vectors,we obtain a certain distribution of carrier energy at each quantized energy level,giving rise to the energy subbands.These results enable carriers to escape from the well under the influence of an electric field.Additionally,we have compiled a comprehensive summary of various energy band scenarios in quantum well structures relevant to carrier transport.Such a new interpretation holds significant value in deepening our comprehension of low-dimensional energy bands,discovering new physical phenomena,and designing novel devices with superior performance.
文摘ICF(inertial confinement fusion)holds significant potential for achieving controlled nuclear fusion,but challenges related to efficient energy transfer and plasma stabilization remains.This article explores the ion-bubble trigger mechanism as a promising solution for improving the compression and energy deposition processes in ICF,particularly when coupled with external magnetic fields,wigglers,undulators,and trapped magnetic fields.The ion-bubble mechanism enhances energy transfer by creating localized heating in the plasma,increasing the likelihood of fusion ignition.External magnetic fields,through their interaction with plasma particles,can optimize ion-bubble interactions by influencing particle trajectories and stabilizing plasma instabilities.Additionally,wigglers and undulators—devices that create oscillating magnetic fields—offer a means to fine-tune the interaction between plasma and electromagnetic radiation,further enhancing the ion-bubble effect.Trapped magnetic fields,formed through plasma compression,also contribute to plasma confinement and stability,offering further support for the ion-bubble trigger mechanism.By combining these factors,the ion-bubble trigger mechanism in ICF could significantly improve fusion efficiency and bring us closer to realizing sustainable fusion energy.
文摘A Si p-π-n diode with β-FeSi 2 particles embedded in the unintentionally doped Si (p--type) was designed for determining the band offset at β-FeSi 2-Si heterojunction.When the diode is under forward bias,the electrons injected via the Si n-p- junction diffuse to and are confined in the β-FeSi 2 particles due to the band offset.The storage charge at the β-FeSi 2-Si heterojunction inversely hamper the further diffusion of electrons,giving rise to the localization of electrons in the p--Si near the Si junction,which prevents them from nonradiative recombination channels.This results in electroluminescence (EL) intensity from both Si and β-FeSi 2 quenching slowly up to room temperature.The temperature dependent ratio of EL intensity of β-FeSi 2 to Si indicates the loss of electron confinement following thermal excitation model.The conduction band offset between Si and β-FeSi 2 is determined to be about 0 2eV.
