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
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
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
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
Langevin molecular dynamics simulations reveal the impact of confinement strength on the structure and dynamics of a two-dimensional complex plasma under constant shear force.Structural analysis via Voronoi diagrams a...Langevin molecular dynamics simulations reveal the impact of confinement strength on the structure and dynamics of a two-dimensional complex plasma under constant shear force.Structural analysis via Voronoi diagrams and the local bond-order parameter|Ψ6|shows that stronger confinement enhances hexagonal order and mitigates shear-induced disorder.Dynamical properties,determined by mean-square displacement(MSD)and the velocity autocorrelation function(VACF),indicate that the shear-induced superdiffusion weakens with increasing confinement strength.The entropy change(?S)shows that strong confinement(ω>1)balances particle dynamics between shear and shear-free regions,thereby stabilizing the system.These findings highlight the interplay between confinement and shear force.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
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
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
Pipelines are extensively used in environments such as nuclear power plants,chemical factories,and medical devices to transport gases and liquids.These tubular environments often feature complex geometries,confined sp...Pipelines are extensively used in environments such as nuclear power plants,chemical factories,and medical devices to transport gases and liquids.These tubular environments often feature complex geometries,confined spaces,and millimeter-scale height restrictions,presenting significant challenges to conventional inspection methods.Here,we present an ultrasonic microrobot(weight,80 mg;dimensions,24 mm×7 mm;thickness,210μm)to realize agile and bidirectional navigation in narrow pipelines.The ultrathin structural design of the robot is achieved through a high-performance piezoelectric composite film microstructure based on MEMS technology.The robot exhibits various vibration modes when driven by ultrasonic frequency signals,its motion speed reaches81 cm s-1 at 54.8 k Hz,exceeding that of the fastest piezoelectric microrobots,and its forward and backward motion direction is controllable through frequency modulation,while the minimum driving voltage for initial movement can be as low as 3 VP-P.Additionally,the robot can effortlessly climb slopes up to 24.25°and carry loads more than 36 times its weight.The robot is capable of agile navigation through curved L-shaped pipes,pipes made of various materials(acrylic,stainless steel,and polyvinyl chloride),and even over water.To further demonstrate its inspection capabilities,a micro-endoscope camera is integrated into the robot,enabling real-time image capture inside glass pipes.展开更多
A 1.3μm low-threshold edge-emitting AlGaInAs multiple-quantum-well(MQW) laser with AlInAs-oxide confinement layers is fabricated.The Al-contained waveguide layers upper and low the active layers are oxidized as curre...A 1.3μm low-threshold edge-emitting AlGaInAs multiple-quantum-well(MQW) laser with AlInAs-oxide confinement layers is fabricated.The Al-contained waveguide layers upper and low the active layers are oxidized as current-confined layers using wet-oxidation technique.This structure provides excellent current and optical confinement,resulting in 12.9mA of a low continuous wave threshold current and 0.47W/A of a high slope efficiency of per facet at room temperature for a 5-μm-wide current aperture.Compared with the ridge waveguide laser with the same-width ridge,the threshold current of the AlInAs-oxide confinement laser has decreased by 31.7% and the slope efficiency has increased a little.Both low threshold and high slope efficiency indicate that lateral current confinement can be realized by oxidizing AlInAs waveguide layers.The full width of half maximum angles of the Al-InAs-oxide confinement laser are 21.6° for the horizontal and 36.1° for the vertical,which demonstrate the ability of the AlInAs oxide in preventing the optical field from spreading laterally.展开更多
With high theoretical energy density and the natural abundance of S, lithium-sulfur （Li-S） batteries areconsidered to be the promising next generation high-energy rechargeable energy storage devices. How-ever, issue...With high theoretical energy density and the natural abundance of S, lithium-sulfur （Li-S） batteries areconsidered to be the promising next generation high-energy rechargeable energy storage devices. How-ever, issues including electronical insulation of S, the lithium polysulfides （LiPSs） dissolution and the shortcycle lifespan have prevented Li-S batteries from being practical applied. Feasible settlements of confiningLiPSs to reduce the loss of active substances and improve the cycle stability include wrapping sulfur withcompact layers, designing matrix with porous or hollow structures, adding adsorbents owning stronginteraction with sulfur and inserting polysulfide barriers between cathodes and separators. This reviewcategorizes them into physical and chemical confinements according to the influencing mechanism. Withfurther discussion of their merits and flaws, synergy of the physical and chemical confinement is believedto be the feasible avenue that can guide Li-S batteries to the practical application.展开更多
In many situations rocks are subjected to biaxial loading and the failure process is controlled by the lateral confinement stresses. The importance of confinement stresses has been recognized in the literature by many...In many situations rocks are subjected to biaxial loading and the failure process is controlled by the lateral confinement stresses. The importance of confinement stresses has been recognized in the literature by many researchers, in particular, its influence on strength and on the angle of fracture, but still there is not a clear description for the influence of confining stress on the crack propagation mechanism of rocks. This paper presents a numerical pro- cedure for the analysis of crack propagation in rock-like ma- terials under compressive biaxial loads. Several numerical simulations of biaxial tests on the rock specimen have been carried out by a bonded particle model （BPM） and the influ- ence of confinement on the mechanism of crack propagation from a single flaw in rock specimens is studied. For this purpose, several biaxial compressive tests on rectangular spec- imens under different confinement stresses were modeled in （2 dimensional particle flow code） PFC2D. The results show that wing cracks initiate perpendicular to the flaw and trend toward the direction of major stress, however, when the lat- eral stresses increase, this initiation angle gets wider. Also it is concluded that in addition to the material type, the initiation direction of the secondary cracks depends on confine- ment stresses, too. Besides, it is understood that secondary cracks may be produced from both tensile and shear mechanisms.展开更多
In this research,a series of biaxial compression and biaxial fatigue tests were conducted to investigate the mechanical behaviors of marble and sandstone under biaxial confinements.Experimental results demonstrate tha...In this research,a series of biaxial compression and biaxial fatigue tests were conducted to investigate the mechanical behaviors of marble and sandstone under biaxial confinements.Experimental results demonstrate that the biaxial compressive strength of rocks under biaxial compression increases firstly,and subsequently decreases with increase of the intermediate principal stress.The fatigue failure characteristics of the rocks in biaxial fatigue tests are functions of the peak value of fatigue loads,the intermediate principal stress and the rock lithology.With the increase of the peak values of fatigue loads,the fatigue lives of rocks decrease.The intermediate principal stress strengthens the resistance ability of rocks to fatigue loads except considering the strength increasing under biaxial confinements.The fatigue lives of rocks increase with the increase of the intermediate principal stress under the same ratio of the fatigue load and their biaxial compressive strength.The acoustic emission(AE)and fragments studies showed that the sandstone has higher ability to resist the fatigue loads compared to the marble,and the marble generated a greater number of smaller fragments after fatigue failure compared to the sandstone.So,it can be inferred that the rock breaking efficiency and rock burst is higher or severer induced by fatigue loading than that induced by monotonous quasi-static loading,especially for hard rocks.展开更多
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 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(Grant No.12075315)。
文摘Langevin molecular dynamics simulations reveal the impact of confinement strength on the structure and dynamics of a two-dimensional complex plasma under constant shear force.Structural analysis via Voronoi diagrams and the local bond-order parameter|Ψ6|shows that stronger confinement enhances hexagonal order and mitigates shear-induced disorder.Dynamical properties,determined by mean-square displacement(MSD)and the velocity autocorrelation function(VACF),indicate that the shear-induced superdiffusion weakens with increasing confinement strength.The entropy change(?S)shows that strong confinement(ω>1)balances particle dynamics between shear and shear-free regions,thereby stabilizing the system.These findings highlight the interplay between confinement and shear force.
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).
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.
基金supported by the National Key Research and Development Program of China(No.2024YFB3212901)National Natural Science Foundation of China(12072189)the Medicine and Engineering Interdisciplinary Research Fund of Shanghai Jiao Tong University(No.YG2025ZD05)。
文摘Pipelines are extensively used in environments such as nuclear power plants,chemical factories,and medical devices to transport gases and liquids.These tubular environments often feature complex geometries,confined spaces,and millimeter-scale height restrictions,presenting significant challenges to conventional inspection methods.Here,we present an ultrasonic microrobot(weight,80 mg;dimensions,24 mm×7 mm;thickness,210μm)to realize agile and bidirectional navigation in narrow pipelines.The ultrathin structural design of the robot is achieved through a high-performance piezoelectric composite film microstructure based on MEMS technology.The robot exhibits various vibration modes when driven by ultrasonic frequency signals,its motion speed reaches81 cm s-1 at 54.8 k Hz,exceeding that of the fastest piezoelectric microrobots,and its forward and backward motion direction is controllable through frequency modulation,while the minimum driving voltage for initial movement can be as low as 3 VP-P.Additionally,the robot can effortlessly climb slopes up to 24.25°and carry loads more than 36 times its weight.The robot is capable of agile navigation through curved L-shaped pipes,pipes made of various materials(acrylic,stainless steel,and polyvinyl chloride),and even over water.To further demonstrate its inspection capabilities,a micro-endoscope camera is integrated into the robot,enabling real-time image capture inside glass pipes.
文摘A 1.3μm low-threshold edge-emitting AlGaInAs multiple-quantum-well(MQW) laser with AlInAs-oxide confinement layers is fabricated.The Al-contained waveguide layers upper and low the active layers are oxidized as current-confined layers using wet-oxidation technique.This structure provides excellent current and optical confinement,resulting in 12.9mA of a low continuous wave threshold current and 0.47W/A of a high slope efficiency of per facet at room temperature for a 5-μm-wide current aperture.Compared with the ridge waveguide laser with the same-width ridge,the threshold current of the AlInAs-oxide confinement laser has decreased by 31.7% and the slope efficiency has increased a little.Both low threshold and high slope efficiency indicate that lateral current confinement can be realized by oxidizing AlInAs waveguide layers.The full width of half maximum angles of the Al-InAs-oxide confinement laser are 21.6° for the horizontal and 36.1° for the vertical,which demonstrate the ability of the AlInAs oxide in preventing the optical field from spreading laterally.
基金supported by Basic Science Center Project of National Natural Science Foundation of China under grant No.51788104the National Natural Science Foundation of China (grant nos.51772301 and 21773264)+1 种基金the National Key R&D Program of China (grant no.2016YFA0202500)the “Strategic Priority Research Program” of the Chinese Academy of Sciences (grant no.XDA09010300)
文摘With high theoretical energy density and the natural abundance of S, lithium-sulfur （Li-S） batteries areconsidered to be the promising next generation high-energy rechargeable energy storage devices. How-ever, issues including electronical insulation of S, the lithium polysulfides （LiPSs） dissolution and the shortcycle lifespan have prevented Li-S batteries from being practical applied. Feasible settlements of confiningLiPSs to reduce the loss of active substances and improve the cycle stability include wrapping sulfur withcompact layers, designing matrix with porous or hollow structures, adding adsorbents owning stronginteraction with sulfur and inserting polysulfide barriers between cathodes and separators. This reviewcategorizes them into physical and chemical confinements according to the influencing mechanism. Withfurther discussion of their merits and flaws, synergy of the physical and chemical confinement is believedto be the feasible avenue that can guide Li-S batteries to the practical application.
文摘In many situations rocks are subjected to biaxial loading and the failure process is controlled by the lateral confinement stresses. The importance of confinement stresses has been recognized in the literature by many researchers, in particular, its influence on strength and on the angle of fracture, but still there is not a clear description for the influence of confining stress on the crack propagation mechanism of rocks. This paper presents a numerical pro- cedure for the analysis of crack propagation in rock-like ma- terials under compressive biaxial loads. Several numerical simulations of biaxial tests on the rock specimen have been carried out by a bonded particle model （BPM） and the influ- ence of confinement on the mechanism of crack propagation from a single flaw in rock specimens is studied. For this purpose, several biaxial compressive tests on rectangular spec- imens under different confinement stresses were modeled in （2 dimensional particle flow code） PFC2D. The results show that wing cracks initiate perpendicular to the flaw and trend toward the direction of major stress, however, when the lat- eral stresses increase, this initiation angle gets wider. Also it is concluded that in addition to the material type, the initiation direction of the secondary cracks depends on confine- ment stresses, too. Besides, it is understood that secondary cracks may be produced from both tensile and shear mechanisms.
基金Projects(51774326,41807259)supported by the National Natural Science Foundation of ChinaProject(MDPC201917)supported by Mining Disaster Prevention and Control Ministry Key Laboratory at Shandong University of Science and Technology,China。
文摘In this research,a series of biaxial compression and biaxial fatigue tests were conducted to investigate the mechanical behaviors of marble and sandstone under biaxial confinements.Experimental results demonstrate that the biaxial compressive strength of rocks under biaxial compression increases firstly,and subsequently decreases with increase of the intermediate principal stress.The fatigue failure characteristics of the rocks in biaxial fatigue tests are functions of the peak value of fatigue loads,the intermediate principal stress and the rock lithology.With the increase of the peak values of fatigue loads,the fatigue lives of rocks decrease.The intermediate principal stress strengthens the resistance ability of rocks to fatigue loads except considering the strength increasing under biaxial confinements.The fatigue lives of rocks increase with the increase of the intermediate principal stress under the same ratio of the fatigue load and their biaxial compressive strength.The acoustic emission(AE)and fragments studies showed that the sandstone has higher ability to resist the fatigue loads compared to the marble,and the marble generated a greater number of smaller fragments after fatigue failure compared to the sandstone.So,it can be inferred that the rock breaking efficiency and rock burst is higher or severer induced by fatigue loading than that induced by monotonous quasi-static loading,especially for hard rocks.
