1. Introduction The discovery of possible high T;super-conductivity at 35K in La-Ba-Cu-O systemsparked an intense study on the new classof cupric oxides by a few laboratoriesincluding the joint research group of highT...1. Introduction The discovery of possible high T;super-conductivity at 35K in La-Ba-Cu-O systemsparked an intense study on the new classof cupric oxides by a few laboratoriesincluding the joint research group of highT;superconductivity in the Institute ofPhysics, Academia Sinica. A few monthslater we not only confirmed the展开更多
ENN is planning the next generation experimental device EHL-2 with the goal to verify the thermal reaction rates of p-^(11)B fusion,establish spherical torus/tokamak experimental scaling laws at 10’s keV ion temperat...ENN is planning the next generation experimental device EHL-2 with the goal to verify the thermal reaction rates of p-^(11)B fusion,establish spherical torus/tokamak experimental scaling laws at 10’s keV ion temperature,and provide a design basis for subsequent experiments to test and realize the p-^(11)B fusion burning plasma.Based on 0-dimensional(0-D)system design and 1.5-dimensional transport modelling analyses,the main target parameters of EHL-2 have been basically determined,including the plasma major radius,R0,of 1.05 m,the aspect ratio,A,of 1.85,the maximum central toroidal magnetic field strength,B0,of 3 T,and the plasma toroidal current,Ip,of 3 MA.The main heating system will be the neutral beam injection at a total power of 17 MW.In addition,6 MW of electron cyclotron resonance heating will serve as the main means of local current drive and MHD instabilities control.The physics design of EHL-2 is focused on addressing three main operating scenarios,i.e.,(1)high ion temperature scenario,(2)high-performance steady-state scenario and(3)high triple product scenario.Each scenario will integrate solutions to different important issues,including equilibrium configuration,heating and current drive,confinement and transport,MHD instability,p-^(11)B fusion reaction,plasma-wall interactions,etc.Beyond that,there are several unique and significant challenges to address,including●establish a plasma with extremely high core ion temperature(T_(i,0)>30 keV),and ensure a large ion-to-electron tempera-ture ratio(T_(i,0)/Te,0>2),and a boron concentration of 10%‒15%at the plasma core;●realize the start-up by non-inductive current drive and the rise of MA-level plasma toroidal current.This is because the volt-seconds that the central solenoid of the ST can provide are very limited;●achieve divertor heat and particle fluxes control including complete detachment under high P/R(>20 MW/m)at rela-tively low electron densities.This overview will introduce the advanced progress in the physics design of EHL-2.展开更多
ENN He Long-2(EHL-2)is the next-generation large mega-Ampere(MA)spherical torus(ST)proposed and funded by the ENN company.The design parameters are:Ti0>30 keV,n_(e0)~1×10^(20)m^(-3),Ip~3 MA,Bt~3 T.One of the b...ENN He Long-2(EHL-2)is the next-generation large mega-Ampere(MA)spherical torus(ST)proposed and funded by the ENN company.The design parameters are:Ti0>30 keV,n_(e0)~1×10^(20)m^(-3),Ip~3 MA,Bt~3 T.One of the biggest challenges of EHL-2 is how to achieve several MA current flat-tops with limited voltage-seconds(Vs)of the center solenoid(CS)coils.In order to minimize the consumption of Vs,a fully non-inductive start-up by electron cyclotron resonance heating(ECRH)will be applied in EHL-2.The ramp-up phase will be accomplished with the synergetic mode between the CS and non-inductive methods.The strategy of non-inductive start-up and ramp-up with synergetic mode has been verified on EXL-50U’s experiments.Based on this strategy,numerical simulations indicate the feasibility of EHL-2 achieving 3 MA plasma current.A high-performance steady-state scenario with Ip~1.5 MA is also designed.In this scenario,the bootstrap current fraction fBS>70%,the safety factor q at the magnetic axis q0>2,the minimum safety factor qmin>1,the poloidal betaβp>3 and normalized betaβN>2.3.Each design iteration integrates the validation of physical models with the constraints of engineering implementation,gradually optimizing the performance of the heating and current drive(H&CD)systems.Numerical simulation results for general auxiliary H&CD systems such as neutral beam injection(NBI),electron cyclotron(EC)wave,ion cyclotron wave(ICW),and lower hybrid wave(LHW)are presented.These simulation results ensure that the 31 MW H&CD systems comprehensively cover all scenarios while maintaining engineering feasibility.展开更多
This paper reviews the energetic particle（EP） experiments during electron cyclotron resonance heating（ECRH） and neutral beam injection in the HL-2 A tokamak.A number of important results are summarized,which relat...This paper reviews the energetic particle（EP） experiments during electron cyclotron resonance heating（ECRH） and neutral beam injection in the HL-2 A tokamak.A number of important results are summarized,which relate to ITER physics,including the behavior of the multi-mode instability,the nonlinear interaction between wave-wave and wave-particles,the losses of EP induced by the instabilities,the effect of the EP instabilities on the thermal plasma confinement and the control of the EP instabilities by means of ECRH.Systematic experiments indicate that when the drive is great enough,the nonlinear effects and the multi-mode coexistence may play an important role,which affect the transport both of the EPs and the background plasma confinement,and these instabilities could be controlled.Some new phenomena about the EP induced instabilities discovered recently on the device,such as high frequency reversed shear Alfvén eigenmodes,Alfvénic ion temperature gradient modes,the geodesic acoustic mode induced by energetic electrons excited by interaction between tearing mode and beta induced Alfvén eigenmode and double e-fishbone in negative magnetic shear discharges etc,have also been presented in the paper.展开更多
Comprehensive understanding and possible control of parametric instabilities in the context of inertial confinement fusion (ICF) remains achallenging task. The details of the absorption processes and the detrimental e...Comprehensive understanding and possible control of parametric instabilities in the context of inertial confinement fusion (ICF) remains achallenging task. The details of the absorption processes and the detrimental effects of hot electrons on the implosion process require as mucheffort on the experimental side as on the theoretical and simulation side. This paper describes a proposal for experimental studies on nonlinearinteraction of intense laser pulses with a high-temperature plasma under conditions corresponding to direct-drive ICF schemes. We propose todevelop a platform for laser-plasma interaction studies based on foam targets. Parametric instabilities are sensitive to the bulk plasma temperatureand the density scale length. Foam targets are sufficiently flexible to allow control of these parameters. However, investigationsconducted on small laser facilities cannot be extrapolated in a reliable way to real fusion conditions. It is therefore necessary to performexperiments at a multi-kilojoule energy level on medium-scale facilities such asOMEGAor SG-III. An example of two-plasmon decay instabilityexcited in the interaction of two laser beams is considered.展开更多
The P3 installation of ELI-Beamlines is conceived as an experimental platform for multiple high-repetition-rate laser beams spanning time scales from femtosecond via picosecond to nanosecond.The upcoming L4n laser bea...The P3 installation of ELI-Beamlines is conceived as an experimental platform for multiple high-repetition-rate laser beams spanning time scales from femtosecond via picosecond to nanosecond.The upcoming L4n laser beamline will provide shaped nanosecond pulses of up to 1.9 kJ at a maximum repetition rate of 1 shot/min.This beamline will provide unique possibilities for high-pressure,high-energy-density physics,warm dense matter,and laser–plasma interaction experiments.Owing to the high repetition rate,it will become possible to obtain considerable improvements in data statistics,in particular,for equation-of-state data sets.The nanosecond beam will be coupled with short sub-picosecond pulses,providing high-resolution diagnostic tools by either irradiating a backlighter target or driving a betatron setup to generate energetic electrons and hard X-rays.展开更多
The physics of laser-plasma interaction is studied on the Shenguang III prototype laser facility under conditions relevant to inertial confinement fusion designs.A sub-millimeter-size underdense hot plasma is created ...The physics of laser-plasma interaction is studied on the Shenguang III prototype laser facility under conditions relevant to inertial confinement fusion designs.A sub-millimeter-size underdense hot plasma is created by ionization of a low-density plastic foam by four high-energy(3.2 kJ)laser beams.An interaction beam is fired with a delay permitting evaluation of the excitation of parametric instabilities at different stages of plasma evolution.Multiple diagnostics are used for plasma characterization,scattered radiation,and accelerated electrons.The experimental results are analyzed with radiation hydrodynamic simulations that take account of foam ionization and homogenization.The measured level of stimulated Raman scattering is almost one order of magnitude larger than that measured in experiments with gasbags and hohlraums on the same installation,possibly because of a greater plasma density.Notable amplification is achieved in high-intensity speckles,indicating the importance of implementing laser temporal smoothing techniques with a large bandwidth for controlling laser propagation and absorption.展开更多
In order to draw the attention of international audience,this author writes up with new clarifications and in an integrated language the one-dimensional physics ofα-LiIO3.The Id accumulations of space charges along t...In order to draw the attention of international audience,this author writes up with new clarifications and in an integrated language the one-dimensional physics ofα-LiIO3.The Id accumulations of space charges along their passageways of the quasi Id ionic flow in the c-direction give rise to the novel phenomena observed in the single crystal specimens under the action of a dc voltage.展开更多
The year 2022 marks the 30^(th)anniversary of Chinese Physics B.This editorial provides a brief history of the journal and introduces the anniversary theme collection comprising over 30 invited reviews and perspective...The year 2022 marks the 30^(th)anniversary of Chinese Physics B.This editorial provides a brief history of the journal and introduces the anniversary theme collection comprising over 30 invited reviews and perspective articles from renowned scholars in various branches of physics.展开更多
It is considered the mechanism of streamer discharge in the wide-gap semiconductors as a highly effective method of the laser excitation on the basis of representation about the phenomenon of light self-trapping of th...It is considered the mechanism of streamer discharge in the wide-gap semiconductors as a highly effective method of the laser excitation on the basis of representation about the phenomenon of light self-trapping of the discharge, providing their high propagation velocity down to v- 5 ×10^9 sm/s, the crystallographic orientation, filamentary character at thickness of the channel about 1 μm and absence of destructions of a crystal.展开更多
The exciting discoveries in astronomy such as the accelerating expansion of the universe, the atmospheric composition of exoplanets, and the abundance trends of various types of stars rely upon advances in laboratory ...The exciting discoveries in astronomy such as the accelerating expansion of the universe, the atmospheric composition of exoplanets, and the abundance trends of various types of stars rely upon advances in laboratory astrophysics. These new discoveries have occurred along with dramatic improvements in measurements by ground- based and space-based instruments of astrophysical processes under extreme physical conditions. Laboratory astrophysics is an exciting and rapidly growing field emerging since the beginning of this century, which covers a wide range of scientific areas such as astrophysics,展开更多
In engineering practice,it is often necessary to determine functional relationships between dependent and independent variables.These relationships can be highly nonlinear,and classical regression approaches cannot al...In engineering practice,it is often necessary to determine functional relationships between dependent and independent variables.These relationships can be highly nonlinear,and classical regression approaches cannot always provide sufficiently reliable solutions.Nevertheless,Machine Learning(ML)techniques,which offer advanced regression tools to address complicated engineering issues,have been developed and widely explored.This study investigates the selected ML techniques to evaluate their suitability for application in the hot deformation behavior of metallic materials.The ML-based regression methods of Artificial Neural Networks(ANNs),Support Vector Machine(SVM),Decision Tree Regression(DTR),and Gaussian Process Regression(GPR)are applied to mathematically describe hot flow stress curve datasets acquired experimentally for a medium-carbon steel.Although the GPR method has not been used for such a regression task before,the results showed that its performance is the most favorable and practically unrivaled;neither the ANN method nor the other studied ML techniques provide such precise results of the solved regression analysis.展开更多
The future large-scale application of sodium-ion batteries(SIBs)is inseparable from their excellent electrochemical performance and reliable safety characteristics.At present,there are few studies focusing on their sa...The future large-scale application of sodium-ion batteries(SIBs)is inseparable from their excellent electrochemical performance and reliable safety characteristics.At present,there are few studies focusing on their safety performance.The analysis of thermal stability and structural changes within a single material cannot systematically describe the complex interplay of components within the battery system during the thermal runaway process.Furthermore,the reaction between the battery materials themselves and their counterparts within the system can stimulate more intense exothermic behavior,thereby affecting the safety of the entire battery system.Therefore,this study delved into the thermal generation and gas evolution characteristics of the positive electrode(Na_(x)Ni_(1/3)Fe_(1/3)Mn_(1/3)O_(2),NFM111)and the negative electrode(hard carbon,HC)in SIBs,utilizing various material combinations.Through the integration of microscopic and macroscopic characterization techniques,the underlying reaction mechanisms of the positive and negative electrode materials within the battery during the heating process were elucidated.Three important results are derived from this study:(Ⅰ)The instability of the solid electrolyte interphase(SEI)leads to its decomposition at temperatures below 100℃,followed by extensive decomposition within the range of 100-150℃,yielding heat and the formation of inorganic compounds,such as Na_(2)CO_(3)and Na_(2)O;(Ⅱ)The reaction between NFM111 and the electrolyte constitutes the primary exothermic event during thermal abuse,with a discernible reaction also occurring between sodium metal and the electrolyte throughout the heating process;(Ⅲ)The heat production and gas generation behaviors of multi-component reactions do not exhibit complete correlation,and the occurrence of gas production does not necessarily coincide with thermal behavior.The results presented in this study can provide useful guidance for the safety improvement of SIBs.展开更多
This work demonstrates experimentally the close relation between return currents from relativistic laser-driven target polarization and the quality of the relativistic laser–plasma interaction for laser-driven second...This work demonstrates experimentally the close relation between return currents from relativistic laser-driven target polarization and the quality of the relativistic laser–plasma interaction for laser-driven secondary sources,taking as an example ion acceleration by target normal sheath acceleration.The Pearson linear correlation of maximum return current amplitude and proton spectrum cutoff energy is found to be in the range from~0.70 to 0.94.kA-scale return currents rise in all interaction schemes where targets of any kind are charged by escaping laser-accelerated relativistic electrons.Their precise measurement is demonstrated using an inductive scheme that allows operation at high repetition rates.Thus,return currents can be used as a metrological online tool for the optimization of many laser-driven secondary sources and for diagnosing their stability.In particular,in two parametric studies of laser-driven ion acceleration,we carry out a noninvasive online measurement of return currents in a tape target system irradiated by the 1 PW VEGA-3 laser at Centro de Láseres Pulsados:first the size of the irradiated area is varied at best compression of the laser pulse;second,the pulse duration is varied by means of induced group delay dispersion at best focus.This work paves the way to the development of feedback systems that operate at the high repetition rates of PW-class lasers.展开更多
Flexible wearable optoelectronic devices fabricated fromorganic–inorganic hybrid perovskites significantly accelerate the developmentof portable energy,biomedicine,and sensing fields,but their poor thermal stabilityh...Flexible wearable optoelectronic devices fabricated fromorganic–inorganic hybrid perovskites significantly accelerate the developmentof portable energy,biomedicine,and sensing fields,but their poor thermal stabilityhinders further applications.Conversely,all-inorganic perovskites possessexcellent thermal stability,but black-phase all-inorganic perovskite filmusually requires high-temperature annealing steps,which increases energy consumptionand is not conducive to the fabrication of flexible wearable devices.In this work,an unprecedented low-temperature fabrication of stable blackphaseCsPbI3perovskite films is demonstrated by the in situ hydrolysis reactionof diphenylphosphinic chloride additive.The released diphenyl phosphateand chloride ions during the hydrolysis reaction significantly lower the phasetransition temperature and effectively passivate the defects in the perovskitefilms,yielding high-performance photodetectors with a responsivity of 42.1 AW−1 and a detectivity of 1.3×10^(14)Jones.Furthermore,high-fidelity imageand photoplethysmography sensors are demonstrated based on the fabricated flexible wearable photodetectors.This work provides a newperspective for the low-temperature fabrication of large-area all-inorganic perovskite flexible optoelectronic devices.展开更多
ZrCoRE(RE denotes rare earth elements)non-evaporable getter films have significant applications in vacuum packaging of micro-electro mechanical system devices because of their excellent gas adsorption performance,low ...ZrCoRE(RE denotes rare earth elements)non-evaporable getter films have significant applications in vacuum packaging of micro-electro mechanical system devices because of their excellent gas adsorption performance,low activation temperature and environmental friendliness.The films were deposited using DC magnetron sputtering with argon and krypton gases under various deposition pressures.The effects of sputtering gas type and pressure on the morphology and hydrogen adsorption performance of ZrCoRE films were investigated.Results show that the films prepared in Ar exhibit a relatively dense structure with fewer grain boundaries.The increase in Ar pressure results in more grain boundaries and gap structures in the films.In contrast,films deposited in Kr display a higher density of grain boundaries and cluster structures,and the films have an obvious columnar crystal structure,with numerous interfaces and gaps distributed between the columnar structures,providing more paths for gas diffusion.As Kr pressure increases,the film demonstrates more pronounced continuous columnar structure growth,accompanied by deeper and wider grain boundaries.This structural configuration provides a larger specific surface area,which significantly improves the hydrogen adsorption speed and capacity.Consequently,high Ar and Kr pressures are beneficial to improve the adsorption performance.展开更多
[Objective]The work is devoted to the study of irreversible deformation of artificial samples subjected to a set of standard experiments,with an aim to study their mechanical properties.The principal idea of the study...[Objective]The work is devoted to the study of irreversible deformation of artificial samples subjected to a set of standard experiments,with an aim to study their mechanical properties.The principal idea of the study is related to the preparation of an artificial material with an established constitutive behavior model.The existence of such a well-described material provides future opportunities to conduct controllable experiments on various mechanical processes in rock-like material for further development and validation of theoretical models used in rock mechanics.[Methods]A set of artificial samples was prepared for careful assessment through a number of loading tests.Experimental work was carried out to determine the rheological properties under conditions of triaxial compression tests and uniaxial tension.Triaxial loading tests are completed for 9 samples with varying radial stress levels(0-5 MPa).The samples are loaded up to the yield point with control of radial and volumetric strain.The experimental results,which contain the obtained interrelationships between axial and radial stresses and strains,are analyzed using the Drucker-Prager yield surface.Material hardening is taken into account through the non-associated plastic flow law with the cap model.Numerical modeling of sample loading is performed through the finite difference method.Mathematical model parameters are adjusted to minimize the discrepancy between numerical modeling results and experimental data.The design of a series of experimental studies necessary to determine all the parameters of the model has been studied.[Results]It is shown that the formulated mathematical model allows to reliably reproduce the inelastic behavior of the studied material,and it can be used to solve a set of applied problems in continuum mechanics,the problem of numerical simulation of hydraulic fracture growth in an elastoplastic medium in particular.It was found that for the entire range of applied lateral loads(0-5 MPa),the elastic limit varied from 2 to 4 MPa,after which the material began to behave plastically.It was also determined that at lateral loads≥3 MPa,compaction began to appear in the material beyond the yield point.Judging by the dependence of volumetric strains under a lateral load equal to 1.4 MPa,compaction should begin to appear even at lateral loads lower than 3 MPa.[Conclusion]Taking the plastic behavior of the material into account is necessary when moving on to modeling the hydraulic fracturing process in such a material,and the resultant plasticity parameters for the model material can be used for numerical modeling of elastoplastic deformation of the rock under consideration,including processes such as hydraulic fracture growth in a poroelastoplastic medium.[Significance]The suggested procedure to interpret results of experimental studies can be used for further numerical modeling of mechanical processes in rock masses with inelastic strain accumulation.This opportunity can increase the reliability of geomechanical models used for the optimization of hydrocarbon fields development.展开更多
Modification of 6061 aluminum alloy was conducted through composite addition of cerium-rich rare earths and Al-Ti-B.Results show that the composite addition of Al-Ti-B and Ce/La element at a specific ratio notably pro...Modification of 6061 aluminum alloy was conducted through composite addition of cerium-rich rare earths and Al-Ti-B.Results show that the composite addition of Al-Ti-B and Ce/La element at a specific ratio notably promotes the refinement of the alloy's grains.Ce and La elements are combined with Si and other elements to form rare earth phases,improving the morphology and distribution of precipitates and mitigating the adverse effects ofβ-Fe phases on the microstructure and mechanical properties of alloy.However,excessive rare earth content poses challenges;it not only leads to a decrease in Mg-Si strengthening phase by binding with Si but also promotes the formation of larger or numerous rare earth phases that may act as initiation points for cracks,thereby impeding the improvement of the structure and performance of alloy.The composite addition of cerium-rich rare earths and Al-Ti-B not only preserves the strength of the alloy but also significantly enhances the plasticity of the 6061 as-cast alloy.At a composite addition ratio of Al-Ti-B:RE=2:1,the newly developed 6061-RE aluminum alloy exhibits increased average elongation by 50%and 45%in its as-cast and homogenized states,respectively,compared to the baseline 6061 alloy,facilitating subsequent deformation processing.After solution treatment at 540℃for 1 h and aging at 180℃for 5 h,the average ultimate tensile strength and yield strength of 6061-RE alloys reach 313.2 and 283.1 MPa,increased by 12.3%and 14.5%compared with those of the original alloy,respectively,and the average elongation is improved by 41%.展开更多
In order to explore the mechanism of improving the surface wettability of low-energy polytetrafluoroethylene(PTFE)by new extended surfactants,five kinds of extended anionic surfactants with different numbers of oxypro...In order to explore the mechanism of improving the surface wettability of low-energy polytetrafluoroethylene(PTFE)by new extended surfactants,five kinds of extended anionic surfactants with different numbers of oxypropylene(PO)and oxyethylene(EO),octadecyl-(PO)_(m)-(EO)_(n)-sodium carboxylate(C_(18)PO_(m)EO_(n)C,m=5,10,15,n=5,10,15),were studied.The surface tension and contact angle of C_(18)PO_(m)EO_(n)C solution with different concentrations were measured,and the adhesion tension,PTFE-water interfacial tension,and adhesion work were calculated.It was found that the extended surfactant molecules adsorb on the surface of the solution and the PTFE-liquid interface simultaneously when the concentration is lower than the critical micelle concentration(cmc),and there was a linear relationship between surface tension and adhesion tension.The adsorption amount of C_(18)PO_(m)EO_(n)C at the PTFE-water interface was significantly lower than that on the surface of the solution.As the concentration increases above cmc,semi-micelle aggregates on the surface of PTFE are formed by C_(18)PO_(m)EO_(n)C molecules through hydrophobic interaction,and the hydrophilic group faces the solution to modify the surface of PTFE with high efficiency.展开更多
Aiming at the problem that infrared small target detection faces low contrast between the background and the target and insufficient noise suppression ability under the complex cloud background,an infrared small targe...Aiming at the problem that infrared small target detection faces low contrast between the background and the target and insufficient noise suppression ability under the complex cloud background,an infrared small target detection method based on the tensor nuclear norm and direction residual weighting was proposed.Based on converting the infrared image into an infrared patch tensor model,from the perspective of the low-rank nature of the background tensor,and taking advantage of the difference in contrast between the background and the target in different directions,we designed a double-neighborhood local contrast based on direction residual weighting method(DNLCDRW)combined with the partial sum of tensor nuclear norm(PSTNN)to achieve effective background suppression and recovery of infrared small targets.Experiments show that the algorithm is effective in suppressing the background and improving the detection ability of the target.展开更多
文摘1. Introduction The discovery of possible high T;super-conductivity at 35K in La-Ba-Cu-O systemsparked an intense study on the new classof cupric oxides by a few laboratoriesincluding the joint research group of highT;superconductivity in the Institute ofPhysics, Academia Sinica. A few monthslater we not only confirmed the
文摘ENN is planning the next generation experimental device EHL-2 with the goal to verify the thermal reaction rates of p-^(11)B fusion,establish spherical torus/tokamak experimental scaling laws at 10’s keV ion temperature,and provide a design basis for subsequent experiments to test and realize the p-^(11)B fusion burning plasma.Based on 0-dimensional(0-D)system design and 1.5-dimensional transport modelling analyses,the main target parameters of EHL-2 have been basically determined,including the plasma major radius,R0,of 1.05 m,the aspect ratio,A,of 1.85,the maximum central toroidal magnetic field strength,B0,of 3 T,and the plasma toroidal current,Ip,of 3 MA.The main heating system will be the neutral beam injection at a total power of 17 MW.In addition,6 MW of electron cyclotron resonance heating will serve as the main means of local current drive and MHD instabilities control.The physics design of EHL-2 is focused on addressing three main operating scenarios,i.e.,(1)high ion temperature scenario,(2)high-performance steady-state scenario and(3)high triple product scenario.Each scenario will integrate solutions to different important issues,including equilibrium configuration,heating and current drive,confinement and transport,MHD instability,p-^(11)B fusion reaction,plasma-wall interactions,etc.Beyond that,there are several unique and significant challenges to address,including●establish a plasma with extremely high core ion temperature(T_(i,0)>30 keV),and ensure a large ion-to-electron tempera-ture ratio(T_(i,0)/Te,0>2),and a boron concentration of 10%‒15%at the plasma core;●realize the start-up by non-inductive current drive and the rise of MA-level plasma toroidal current.This is because the volt-seconds that the central solenoid of the ST can provide are very limited;●achieve divertor heat and particle fluxes control including complete detachment under high P/R(>20 MW/m)at rela-tively low electron densities.This overview will introduce the advanced progress in the physics design of EHL-2.
基金supported by ENN Group and ENN Energy Research Institute.The authors would like to express their gratitude for the contributions of the ENN fusion team and collaborators,such as Tiantian Sun,Haojie Ma,and Yong Guo,in supporting these endeavours.The authors also acknowledge the support of the National SuperComputer Center in Tianjin and Beijing PARATERA Tech Corp.,Ltd.,for providing HPC resources that have contributed to the research results reported in this paper.This work was partly supported by National Natural Science Fundation of China(Nos.12375215 and 12475210).
文摘ENN He Long-2(EHL-2)is the next-generation large mega-Ampere(MA)spherical torus(ST)proposed and funded by the ENN company.The design parameters are:Ti0>30 keV,n_(e0)~1×10^(20)m^(-3),Ip~3 MA,Bt~3 T.One of the biggest challenges of EHL-2 is how to achieve several MA current flat-tops with limited voltage-seconds(Vs)of the center solenoid(CS)coils.In order to minimize the consumption of Vs,a fully non-inductive start-up by electron cyclotron resonance heating(ECRH)will be applied in EHL-2.The ramp-up phase will be accomplished with the synergetic mode between the CS and non-inductive methods.The strategy of non-inductive start-up and ramp-up with synergetic mode has been verified on EXL-50U’s experiments.Based on this strategy,numerical simulations indicate the feasibility of EHL-2 achieving 3 MA plasma current.A high-performance steady-state scenario with Ip~1.5 MA is also designed.In this scenario,the bootstrap current fraction fBS>70%,the safety factor q at the magnetic axis q0>2,the minimum safety factor qmin>1,the poloidal betaβp>3 and normalized betaβN>2.3.Each design iteration integrates the validation of physical models with the constraints of engineering implementation,gradually optimizing the performance of the heating and current drive(H&CD)systems.Numerical simulation results for general auxiliary H&CD systems such as neutral beam injection(NBI),electron cyclotron(EC)wave,ion cyclotron wave(ICW),and lower hybrid wave(LHW)are presented.These simulation results ensure that the 31 MW H&CD systems comprehensively cover all scenarios while maintaining engineering feasibility.
基金supported by National Natural Science Foundation of China under Grant Nos.11005035,11475058the National Magnetic Confinement Fusion Science Program of China(ITERCN) under Grant Nos.2013GB104001 and 2013GB106004
文摘This paper reviews the energetic particle（EP） experiments during electron cyclotron resonance heating（ECRH） and neutral beam injection in the HL-2 A tokamak.A number of important results are summarized,which relate to ITER physics,including the behavior of the multi-mode instability,the nonlinear interaction between wave-wave and wave-particles,the losses of EP induced by the instabilities,the effect of the EP instabilities on the thermal plasma confinement and the control of the EP instabilities by means of ECRH.Systematic experiments indicate that when the drive is great enough,the nonlinear effects and the multi-mode coexistence may play an important role,which affect the transport both of the EPs and the background plasma confinement,and these instabilities could be controlled.Some new phenomena about the EP induced instabilities discovered recently on the device,such as high frequency reversed shear Alfvén eigenmodes,Alfvénic ion temperature gradient modes,the geodesic acoustic mode induced by energetic electrons excited by interaction between tearing mode and beta induced Alfvén eigenmode and double e-fishbone in negative magnetic shear discharges etc,have also been presented in the paper.
基金The authors acknowledge support from the European Regional Development Fund for the following projects:HiFI(No.CZ.02.1.01/0.0/0.0/15_003/0000449),CAAS(No.CZ.02.1.01/0.0/0.0/16_019/0000778),ADONIS(No.CZ.02.1.01/0.0/0.0/16_019/0000789),and ELITAS(No.CZ.02.1.01/0.0/0.0/16_013/0001793)This work has received funding from the European Union Horizon 2020 Research and Innovation Programme under Grant Agreement No.633053(EUROfusion Project No.CfP-AWP17-IFE-CEA-01)+2 种基金Computational resources were provided by the MetaCentrum under the LM2010005 projectIT4InnovationsCentre of Excellence under the CZ.1.05/1.1.00/02.0070 and LM2011033 projectsthe ECLIPSE cluster of ELI-Beamlines.The EPOCH code was developed as part of the UK EPSRC-funded EP/G054940/1 project.
文摘Comprehensive understanding and possible control of parametric instabilities in the context of inertial confinement fusion (ICF) remains achallenging task. The details of the absorption processes and the detrimental effects of hot electrons on the implosion process require as mucheffort on the experimental side as on the theoretical and simulation side. This paper describes a proposal for experimental studies on nonlinearinteraction of intense laser pulses with a high-temperature plasma under conditions corresponding to direct-drive ICF schemes. We propose todevelop a platform for laser-plasma interaction studies based on foam targets. Parametric instabilities are sensitive to the bulk plasma temperatureand the density scale length. Foam targets are sufficiently flexible to allow control of these parameters. However, investigationsconducted on small laser facilities cannot be extrapolated in a reliable way to real fusion conditions. It is therefore necessary to performexperiments at a multi-kilojoule energy level on medium-scale facilities such asOMEGAor SG-III. An example of two-plasmon decay instabilityexcited in the interaction of two laser beams is considered.
基金The authors acknowledge support from the projects“Advanced Research Using High Intensity Laser Produced Photons and Particles(ADONIS)”(Grant No.CZ.02.1.01/0.0/0.0/16_019/0000789)“High Field Initiative(HiFI)”(Grant No.CZ.02.1.01/0.0/0.0/15_003/0000449)both from the European Regional Development Fund.The results of the Project LQ1606 were obtained with financial support from the Ministry of Education,Youth and Sports as part of targeted support from the National Program of Sustainability II.
文摘The P3 installation of ELI-Beamlines is conceived as an experimental platform for multiple high-repetition-rate laser beams spanning time scales from femtosecond via picosecond to nanosecond.The upcoming L4n laser beamline will provide shaped nanosecond pulses of up to 1.9 kJ at a maximum repetition rate of 1 shot/min.This beamline will provide unique possibilities for high-pressure,high-energy-density physics,warm dense matter,and laser–plasma interaction experiments.Owing to the high repetition rate,it will become possible to obtain considerable improvements in data statistics,in particular,for equation-of-state data sets.The nanosecond beam will be coupled with short sub-picosecond pulses,providing high-resolution diagnostic tools by either irradiating a backlighter target or driving a betatron setup to generate energetic electrons and hard X-rays.
基金This project was partially supported by the Advanced Research Using High Intensity Laser Produced Photons and Particles(ADONIS)project(Grant No.CZ.02.1.01/0.0/0.0/16_019/0000789)the CAAS project(Grant No.CZ.02.1.01/0.0/0.0/16_019/0000778)+3 种基金both from the European Regional Development FundThe results of the LQ1606 project were partially obtained with the financial support from the Ministry of Education,Youth and Sports as part of targeted support from the National Programme of Sustainability IIThe authors acknowledge support from the National Natural Science Foundation of China(Grant Nos.11775033,11875241,11975215,11905204,12035002)the Laser Fusion Research Center Funds for Young Talents(Grant No.RCFPD3-2019-6).
文摘The physics of laser-plasma interaction is studied on the Shenguang III prototype laser facility under conditions relevant to inertial confinement fusion designs.A sub-millimeter-size underdense hot plasma is created by ionization of a low-density plastic foam by four high-energy(3.2 kJ)laser beams.An interaction beam is fired with a delay permitting evaluation of the excitation of parametric instabilities at different stages of plasma evolution.Multiple diagnostics are used for plasma characterization,scattered radiation,and accelerated electrons.The experimental results are analyzed with radiation hydrodynamic simulations that take account of foam ionization and homogenization.The measured level of stimulated Raman scattering is almost one order of magnitude larger than that measured in experiments with gasbags and hohlraums on the same installation,possibly because of a greater plasma density.Notable amplification is achieved in high-intensity speckles,indicating the importance of implementing laser temporal smoothing techniques with a large bandwidth for controlling laser propagation and absorption.
文摘In order to draw the attention of international audience,this author writes up with new clarifications and in an integrated language the one-dimensional physics ofα-LiIO3.The Id accumulations of space charges along their passageways of the quasi Id ionic flow in the c-direction give rise to the novel phenomena observed in the single crystal specimens under the action of a dc voltage.
文摘The year 2022 marks the 30^(th)anniversary of Chinese Physics B.This editorial provides a brief history of the journal and introduces the anniversary theme collection comprising over 30 invited reviews and perspective articles from renowned scholars in various branches of physics.
文摘It is considered the mechanism of streamer discharge in the wide-gap semiconductors as a highly effective method of the laser excitation on the basis of representation about the phenomenon of light self-trapping of the discharge, providing their high propagation velocity down to v- 5 ×10^9 sm/s, the crystallographic orientation, filamentary character at thickness of the channel about 1 μm and absence of destructions of a crystal.
文摘The exciting discoveries in astronomy such as the accelerating expansion of the universe, the atmospheric composition of exoplanets, and the abundance trends of various types of stars rely upon advances in laboratory astrophysics. These new discoveries have occurred along with dramatic improvements in measurements by ground- based and space-based instruments of astrophysical processes under extreme physical conditions. Laboratory astrophysics is an exciting and rapidly growing field emerging since the beginning of this century, which covers a wide range of scientific areas such as astrophysics,
基金supported by the SP2024/089 Project by the Faculty of Materials Science and Technology,VˇSB-Technical University of Ostrava.
文摘In engineering practice,it is often necessary to determine functional relationships between dependent and independent variables.These relationships can be highly nonlinear,and classical regression approaches cannot always provide sufficiently reliable solutions.Nevertheless,Machine Learning(ML)techniques,which offer advanced regression tools to address complicated engineering issues,have been developed and widely explored.This study investigates the selected ML techniques to evaluate their suitability for application in the hot deformation behavior of metallic materials.The ML-based regression methods of Artificial Neural Networks(ANNs),Support Vector Machine(SVM),Decision Tree Regression(DTR),and Gaussian Process Regression(GPR)are applied to mathematically describe hot flow stress curve datasets acquired experimentally for a medium-carbon steel.Although the GPR method has not been used for such a regression task before,the results showed that its performance is the most favorable and practically unrivaled;neither the ANN method nor the other studied ML techniques provide such precise results of the solved regression analysis.
基金supported by the National Natural Science Foundation of China(52404259)supported by Youth Innovation Promotion Association CAS(Y201768)。
文摘The future large-scale application of sodium-ion batteries(SIBs)is inseparable from their excellent electrochemical performance and reliable safety characteristics.At present,there are few studies focusing on their safety performance.The analysis of thermal stability and structural changes within a single material cannot systematically describe the complex interplay of components within the battery system during the thermal runaway process.Furthermore,the reaction between the battery materials themselves and their counterparts within the system can stimulate more intense exothermic behavior,thereby affecting the safety of the entire battery system.Therefore,this study delved into the thermal generation and gas evolution characteristics of the positive electrode(Na_(x)Ni_(1/3)Fe_(1/3)Mn_(1/3)O_(2),NFM111)and the negative electrode(hard carbon,HC)in SIBs,utilizing various material combinations.Through the integration of microscopic and macroscopic characterization techniques,the underlying reaction mechanisms of the positive and negative electrode materials within the battery during the heating process were elucidated.Three important results are derived from this study:(Ⅰ)The instability of the solid electrolyte interphase(SEI)leads to its decomposition at temperatures below 100℃,followed by extensive decomposition within the range of 100-150℃,yielding heat and the formation of inorganic compounds,such as Na_(2)CO_(3)and Na_(2)O;(Ⅱ)The reaction between NFM111 and the electrolyte constitutes the primary exothermic event during thermal abuse,with a discernible reaction also occurring between sodium metal and the electrolyte throughout the heating process;(Ⅲ)The heat production and gas generation behaviors of multi-component reactions do not exhibit complete correlation,and the occurrence of gas production does not necessarily coincide with thermal behavior.The results presented in this study can provide useful guidance for the safety improvement of SIBs.
基金funding from the European Union’s Horizon 2020 research and innovation program through the European IMPULSE project under Grant Agreement No.871161from LASERLAB-EUROPE V under Grant Agreement No.871124+6 种基金from the Grant Agency of the Czech Republic(Grant No.GM23-05027M)Grant No.PDC2021120933-I00 funded by MCIN/AEI/10.13039/501100011033by the European Union Next Generation EU/PRTRsupported by funding from the Ministerio de Ciencia,Innovación y Universidades in Spain through ICTS Equipment Grant No.EQC2018-005230-Pfrom Grant No.PID2021-125389O A-I00 funded by MCIN/AEI/10.13039/501100011033/FEDER,UEby“ERDF A Way of Making Europe”by the European Unionfrom grants of the Junta de Castilla y León with Grant Nos.CLP263P20 and CLP087U16。
文摘This work demonstrates experimentally the close relation between return currents from relativistic laser-driven target polarization and the quality of the relativistic laser–plasma interaction for laser-driven secondary sources,taking as an example ion acceleration by target normal sheath acceleration.The Pearson linear correlation of maximum return current amplitude and proton spectrum cutoff energy is found to be in the range from~0.70 to 0.94.kA-scale return currents rise in all interaction schemes where targets of any kind are charged by escaping laser-accelerated relativistic electrons.Their precise measurement is demonstrated using an inductive scheme that allows operation at high repetition rates.Thus,return currents can be used as a metrological online tool for the optimization of many laser-driven secondary sources and for diagnosing their stability.In particular,in two parametric studies of laser-driven ion acceleration,we carry out a noninvasive online measurement of return currents in a tape target system irradiated by the 1 PW VEGA-3 laser at Centro de Láseres Pulsados:first the size of the irradiated area is varied at best compression of the laser pulse;second,the pulse duration is varied by means of induced group delay dispersion at best focus.This work paves the way to the development of feedback systems that operate at the high repetition rates of PW-class lasers.
基金supported by the National Natural Science Foundation of China(52303257,52321006,T2394480,and T2394484)the National Key R&D Program of China(Grant No.2023YFE0111500)+3 种基金Key Research&Development and Promotion of Special Project(Scientific Problem Tackling)of Henan Province(242102211090)the China Postdoctoral Science Foundation(2023TQ0300,and 2023M743171)the Postdoctoral Fellowship Program(Grade B)of China Postdoctoral Science Foundation(GZB20230666)College Student Innovation and Entrepreneurship Training Program of Zhengzhou University(202410459200)。
文摘Flexible wearable optoelectronic devices fabricated fromorganic–inorganic hybrid perovskites significantly accelerate the developmentof portable energy,biomedicine,and sensing fields,but their poor thermal stabilityhinders further applications.Conversely,all-inorganic perovskites possessexcellent thermal stability,but black-phase all-inorganic perovskite filmusually requires high-temperature annealing steps,which increases energy consumptionand is not conducive to the fabrication of flexible wearable devices.In this work,an unprecedented low-temperature fabrication of stable blackphaseCsPbI3perovskite films is demonstrated by the in situ hydrolysis reactionof diphenylphosphinic chloride additive.The released diphenyl phosphateand chloride ions during the hydrolysis reaction significantly lower the phasetransition temperature and effectively passivate the defects in the perovskitefilms,yielding high-performance photodetectors with a responsivity of 42.1 AW−1 and a detectivity of 1.3×10^(14)Jones.Furthermore,high-fidelity imageand photoplethysmography sensors are demonstrated based on the fabricated flexible wearable photodetectors.This work provides a newperspective for the low-temperature fabrication of large-area all-inorganic perovskite flexible optoelectronic devices.
基金National Natural Science Foundation of China(62171208)Natural Science Foundation of Gansu Province(23JRRA1355)。
文摘ZrCoRE(RE denotes rare earth elements)non-evaporable getter films have significant applications in vacuum packaging of micro-electro mechanical system devices because of their excellent gas adsorption performance,low activation temperature and environmental friendliness.The films were deposited using DC magnetron sputtering with argon and krypton gases under various deposition pressures.The effects of sputtering gas type and pressure on the morphology and hydrogen adsorption performance of ZrCoRE films were investigated.Results show that the films prepared in Ar exhibit a relatively dense structure with fewer grain boundaries.The increase in Ar pressure results in more grain boundaries and gap structures in the films.In contrast,films deposited in Kr display a higher density of grain boundaries and cluster structures,and the films have an obvious columnar crystal structure,with numerous interfaces and gaps distributed between the columnar structures,providing more paths for gas diffusion.As Kr pressure increases,the film demonstrates more pronounced continuous columnar structure growth,accompanied by deeper and wider grain boundaries.This structural configuration provides a larger specific surface area,which significantly improves the hydrogen adsorption speed and capacity.Consequently,high Ar and Kr pressures are beneficial to improve the adsorption performance.
文摘[Objective]The work is devoted to the study of irreversible deformation of artificial samples subjected to a set of standard experiments,with an aim to study their mechanical properties.The principal idea of the study is related to the preparation of an artificial material with an established constitutive behavior model.The existence of such a well-described material provides future opportunities to conduct controllable experiments on various mechanical processes in rock-like material for further development and validation of theoretical models used in rock mechanics.[Methods]A set of artificial samples was prepared for careful assessment through a number of loading tests.Experimental work was carried out to determine the rheological properties under conditions of triaxial compression tests and uniaxial tension.Triaxial loading tests are completed for 9 samples with varying radial stress levels(0-5 MPa).The samples are loaded up to the yield point with control of radial and volumetric strain.The experimental results,which contain the obtained interrelationships between axial and radial stresses and strains,are analyzed using the Drucker-Prager yield surface.Material hardening is taken into account through the non-associated plastic flow law with the cap model.Numerical modeling of sample loading is performed through the finite difference method.Mathematical model parameters are adjusted to minimize the discrepancy between numerical modeling results and experimental data.The design of a series of experimental studies necessary to determine all the parameters of the model has been studied.[Results]It is shown that the formulated mathematical model allows to reliably reproduce the inelastic behavior of the studied material,and it can be used to solve a set of applied problems in continuum mechanics,the problem of numerical simulation of hydraulic fracture growth in an elastoplastic medium in particular.It was found that for the entire range of applied lateral loads(0-5 MPa),the elastic limit varied from 2 to 4 MPa,after which the material began to behave plastically.It was also determined that at lateral loads≥3 MPa,compaction began to appear in the material beyond the yield point.Judging by the dependence of volumetric strains under a lateral load equal to 1.4 MPa,compaction should begin to appear even at lateral loads lower than 3 MPa.[Conclusion]Taking the plastic behavior of the material into account is necessary when moving on to modeling the hydraulic fracturing process in such a material,and the resultant plasticity parameters for the model material can be used for numerical modeling of elastoplastic deformation of the rock under consideration,including processes such as hydraulic fracture growth in a poroelastoplastic medium.[Significance]The suggested procedure to interpret results of experimental studies can be used for further numerical modeling of mechanical processes in rock masses with inelastic strain accumulation.This opportunity can increase the reliability of geomechanical models used for the optimization of hydrocarbon fields development.
基金Subproject of Inner Mongolia Autonomous Region Key Research and Development and Achievement Transformation Plan Project(2023YFDZ0064,2023KJHZ0020,2022YFDZ0097)Natural Science Foundation of Inner Mongolia Autonomous Region of China(2022QN05040)+1 种基金Basic Research Funds for Directly Affiliated Universities in Inner Mongolia Autonomous Region(JY20220093)Program for Young Talents of Science and Technology in Universities of Inner Mongolia Autonomous Region(NJYT24008)。
文摘Modification of 6061 aluminum alloy was conducted through composite addition of cerium-rich rare earths and Al-Ti-B.Results show that the composite addition of Al-Ti-B and Ce/La element at a specific ratio notably promotes the refinement of the alloy's grains.Ce and La elements are combined with Si and other elements to form rare earth phases,improving the morphology and distribution of precipitates and mitigating the adverse effects ofβ-Fe phases on the microstructure and mechanical properties of alloy.However,excessive rare earth content poses challenges;it not only leads to a decrease in Mg-Si strengthening phase by binding with Si but also promotes the formation of larger or numerous rare earth phases that may act as initiation points for cracks,thereby impeding the improvement of the structure and performance of alloy.The composite addition of cerium-rich rare earths and Al-Ti-B not only preserves the strength of the alloy but also significantly enhances the plasticity of the 6061 as-cast alloy.At a composite addition ratio of Al-Ti-B:RE=2:1,the newly developed 6061-RE aluminum alloy exhibits increased average elongation by 50%and 45%in its as-cast and homogenized states,respectively,compared to the baseline 6061 alloy,facilitating subsequent deformation processing.After solution treatment at 540℃for 1 h and aging at 180℃for 5 h,the average ultimate tensile strength and yield strength of 6061-RE alloys reach 313.2 and 283.1 MPa,increased by 12.3%and 14.5%compared with those of the original alloy,respectively,and the average elongation is improved by 41%.
文摘In order to explore the mechanism of improving the surface wettability of low-energy polytetrafluoroethylene(PTFE)by new extended surfactants,five kinds of extended anionic surfactants with different numbers of oxypropylene(PO)and oxyethylene(EO),octadecyl-(PO)_(m)-(EO)_(n)-sodium carboxylate(C_(18)PO_(m)EO_(n)C,m=5,10,15,n=5,10,15),were studied.The surface tension and contact angle of C_(18)PO_(m)EO_(n)C solution with different concentrations were measured,and the adhesion tension,PTFE-water interfacial tension,and adhesion work were calculated.It was found that the extended surfactant molecules adsorb on the surface of the solution and the PTFE-liquid interface simultaneously when the concentration is lower than the critical micelle concentration(cmc),and there was a linear relationship between surface tension and adhesion tension.The adsorption amount of C_(18)PO_(m)EO_(n)C at the PTFE-water interface was significantly lower than that on the surface of the solution.As the concentration increases above cmc,semi-micelle aggregates on the surface of PTFE are formed by C_(18)PO_(m)EO_(n)C molecules through hydrophobic interaction,and the hydrophilic group faces the solution to modify the surface of PTFE with high efficiency.
基金Supported by the Key Laboratory Fund for Equipment Pre-Research(6142207210202)。
文摘Aiming at the problem that infrared small target detection faces low contrast between the background and the target and insufficient noise suppression ability under the complex cloud background,an infrared small target detection method based on the tensor nuclear norm and direction residual weighting was proposed.Based on converting the infrared image into an infrared patch tensor model,from the perspective of the low-rank nature of the background tensor,and taking advantage of the difference in contrast between the background and the target in different directions,we designed a double-neighborhood local contrast based on direction residual weighting method(DNLCDRW)combined with the partial sum of tensor nuclear norm(PSTNN)to achieve effective background suppression and recovery of infrared small targets.Experiments show that the algorithm is effective in suppressing the background and improving the detection ability of the target.
