Recovered samples of Jilin H5 chondrite experimentally shocked to 12-133 GPa were studied to explore the behavior of opaque minerals under shock loading using SEM-EDS,Raman spectroscopy,and TIMA.The following results ...Recovered samples of Jilin H5 chondrite experimentally shocked to 12-133 GPa were studied to explore the behavior of opaque minerals under shock loading using SEM-EDS,Raman spectroscopy,and TIMA.The following results were obtained.Firstly,at pressures lower than 53GPa,the opaque minerals still keep the unmelted state,while at 78 GPa and higher,FeNi metal and troilite form eutectic intergrowths occurring as disorderly fine veinlets filling the shock-induced fractures in silicate minerals.Secondly,single kamacite grains still maintain their contour at 12 GPa,but a part of brittle troilite grains was fragmented and squeezed into the shock-induced fractures within kamacite grains.At53 and 133 GPa,many more troilite fragments are poured in the kamacite interior to form disordered hybrid aggregates or to form squiggly strips,respectively.Similar phenomena are observed within single troilite grains,but the mineral squeezed into troilite grains is kamacite.Thirdly,chromite is a hard and refractory oxide mineral.When the shock pressure rises step by step from 12 to 133 GPa,the shock effect of chromite is only fragmentation.Its grain size decreases from tens of um at 53 GPa to a few um at 133 GPa.And,fourthly,native copper exhibits distinct redistribution behavior at high temperature.In Jilin samples shock-loaded to 12 GPa,copper initially located at troilite-kamacite interfaces partially transferred into small troilite grains containing fine FeNi particles.At 53 and 133 GPa,native copper preferentially transferred into larger troilite grains containing more particles of eutectic FeNi metal.展开更多
The phase transition behaviors of the shocked water are investigated by employing an optical transmittance in-situ detection system.Based on the light scattering theory and phase transformation kinetics,the phase tran...The phase transition behaviors of the shocked water are investigated by employing an optical transmittance in-situ detection system.Based on the light scattering theory and phase transformation kinetics,the phase transition mechanism of the water under multiple shocks is discussed.The experimental data indicate that the evolution of the transmittance of the shocked water can be broadly divided into three stages:relaxation stage,decline stage,and recovery stage.In the early stage of the phase transition,the new phase particles began to form around the quartz/window interface.It should be mentioned that the water/ice phase boundary seems to move toward the liquid region in one experiment of this work.Due to the new phase core being much smaller than the wavelength of the incident light,the transmittance of the sample within the relaxation stage remains steady.The decline stage can be divided into the rapid descent stage and the slow descent stage in this work,which is considered as the different growth rates of the new phase particle under different shock loadings.The recovery stage is attributed to the emergence of the new phase particles which are bigger than the critical value.However,the influence of the size growth and the population growth of the new phase particles on the transmittance restrict each other,which may be responsible for the phenomenon that the transmittance curve does not return to the initial level.展开更多
We have calculated the Hugoniot properties of shocked nitromethane based on the improved Tsien＇s equa- tion of state （EOS） that optimized by ＂exact＂ numerical molecular dynamic data at high temperatures and press...We have calculated the Hugoniot properties of shocked nitromethane based on the improved Tsien＇s equa- tion of state （EOS） that optimized by ＂exact＂ numerical molecular dynamic data at high temperatures and pressures. Comparison of the calculated results of the improved Tsien＇s EOS with the existed experimental data and the direct simu- lations show that the behavior of the improved Tsien＇s EOS is very good in many aspects. Because of its simple analytical form, the improved Tsien＇s EOS can be prospectively used to study the condensed explosive detonation coupling with chemical reaction.展开更多
Raman spectra of liquid nitromethane were measured in single-shock experiments using transient Raman scattering system with high sensitivity. The measurement system was combined with a two-stage light gas gun to inter...Raman spectra of liquid nitromethane were measured in single-shock experiments using transient Raman scattering system with high sensitivity. The measurement system was combined with a two-stage light gas gun to interrogate the vibrational mode-dependent behaviors of shock-compressed nitromethane molecules. Up to 12 GPa, all Raman peaks were able to be clearly detected, and showed the shock-induced shifting and broadening, but no signs of chemical changes occurred in the sample. Thus, it is concluded that chemical reactions could not be initiated in singly-shocked nitromethane below 12 GPa.展开更多
AIM. To study whether heat-shocked tumor cells could enhance the effect of tumor cell lysate-pulsed dendritic cells （DCs） in evoking anti-tumor immune response in vivo. METHODS： Mouse undifferentiated colon cancer ...AIM. To study whether heat-shocked tumor cells could enhance the effect of tumor cell lysate-pulsed dendritic cells （DCs） in evoking anti-tumor immune response in vivo. METHODS： Mouse undifferentiated colon cancer cells （CT-26） were heated at 42℃ for 1 h and then frozenthawed. The bone marrow-derived DCs pulsed with heatshocked CT-26 cell lysate （HSCT-26 DCs） were recruited to immunize syngeneic naive BALB/c mice. The cytotoxic activity of tumor specific cytotoxic T lymphocytes （CTLs） in mouse spleen was evaluated by IFN-enzyme-linked immunospot （ELISpot） and LDH release assay. The immunoprophylactic effects induced by HSCT-26 DCs in mouse colon cancer model were compared to those induced by single CT-26 cell lysate-pulsed DCs （CT-26 DCs） on tumor volume, peritoneal metastasis and survival time of the mice. RESULTS： Heat-treated CT-26 cells showed a higher hsp70 protein expression. Heat-shocked CT-26 cell lysate pulsing elevated the co-stimulatory and MHC-Ⅱ molecule expression of bone marrow-derived DCs as well as interleukin-12 p70 secretion. The IFN-y secreting CTLs induced by HSCT-26 DCs were significantly more than those induced by CT-26 DCs （P=0.002）. The former CTLs＇ specific cytotoxic activity was higher than the latter CTLs＇ at a serial E/T ratio of 10：1, 20：1, and 40：1. Mouse colon cancer model showed that the tumor volume of HSCT-26 DC vaccination group was smaller than that of CT-26 DC vaccination group on tumor volume though there was no statistical difference between them （24 mm^3 vs 8 mm^3, P=0.480）. The median survival time of mice immunized with HSCT-26 DCs was longer than that of those immunized with CT-26 DCs （57 d vs 43 d, P = 0.0384）. CONCLUSION： Heat-shocked tumor cell lysate-pulsed DCs can evoke anti-tumor immune response in vivo effectively and serve as a novel DC-based tumor vaccine.展开更多
We apply a hydrodynamic approach to analyze ejecta emanating from doubly shocked liquid metals. In particular, we are interested incharacterizing ejecta velocities in such situations by treating the problem as a limit...We apply a hydrodynamic approach to analyze ejecta emanating from doubly shocked liquid metals. In particular, we are interested incharacterizing ejecta velocities in such situations by treating the problem as a limiting case of the Richtmyer–Meshkov instability. We findexisting models for ejecta velocities do not adequately capture all the relevant physics, including compressibility, nonlinearities, and nonstandardshapes. We propose an empirical model that is capable of describing ejecta behavior across the entire parameter range of interest. We thensuggest a protocol to apply this model when the donor material is shocked twice in rapid succession. Finally, the model and the suggestedapproach are validated using detailed continuum hydrodynamic simulations. The results provide a baseline understanding of the hydrodynamicaspects of ejecta, which can then be used to interpret experimental data from target experiments.展开更多
Copper possesses very strong chacophile properties,but under the conditions found in meteorites,its behavior is like that of siderophile elements.The Suizhou meteorite is a highly shocked L6 chondrite.Troilite and tae...Copper possesses very strong chacophile properties,but under the conditions found in meteorites,its behavior is like that of siderophile elements.The Suizhou meteorite is a highly shocked L6 chondrite.Troilite and taenite are considered the main primary carrier of copper in this meteorite,and the post-shock thermal episode is considered the main reason that elemental Cu migrates from its original host phase and forms metallic grains.The Suizhou meteorite contains a few very thin shock melt veins.The occurrence and behavior of metallic copper in this meteorite were studied by optical microscopic examination,electron microprobe analyses,and high-resolution X-ray elemental intensity mapping.Our results show that metallic copper is abundant in the Suizhou chondritic rock.Metallic copper grains adjacent to small troilite grains inside FeNi metal are the most common occurrence,and those at the FeNi metal–troilite interface are the second most common case.The metallic copper grains occurring at the interface of FeNi metal/troililte and silicate are rather rare.Metallic copper grains are not observed within the Suizhou shock veins,Instead,Cu in elemental form is transferred through shock metamorphism into FeNi metal+troilite intergrowths.Four diff erent occurrence types of Cu in the FeNi metal+troilite intergrowths have been identifi ed:the concentrations of Cu in the FeNi+FeS intergrowths for four occurrence types are rather close,we estimate it might be lower than 1 wt%.展开更多
We conduct molecular dynamics simulations of the ejection process from a grooved Pb surface subjected to supported and unsupported shock waves with various shock-breakout pressures（PSB） inducing a solid–liquid phas...We conduct molecular dynamics simulations of the ejection process from a grooved Pb surface subjected to supported and unsupported shock waves with various shock-breakout pressures（PSB） inducing a solid–liquid phase transition upon shock or release. It is found that the total ejecta mass changing with PSBunder a supported shock reveals a similar trend with that under an unsupported shock and the former is always less than the latter at the same PSB. The origin of such a discrepancy could be unraveled that for an unsupported shock, a larger velocity difference between the jet tip and its bottom at an early stage of jet formation results in more serious damage, and therefore a greater amount of ejected particles are produced. The cumulative areal density distributions also display the discrepancy. In addition, we discuss the difference of these simulated results compared to the experimental findings.展开更多
Sound velocities in shock-loaded solids are not only important to determine bulk moduli of solids at high pressures, but are also crucial to inform the shock melting of solids upon loading. In this letter, we first re...Sound velocities in shock-loaded solids are not only important to determine bulk moduli of solids at high pressures, but are also crucial to inform the shock melting of solids upon loading. In this letter, we first report on shock melting of porous solids at high pressures by measuring sound velocities in the porous iron of average density 6.90 g/cm^(3) in the pressure range of 110-180 GPa. The measured sound velocity softens at pressures from 122 to 156 Gpa, which may be attributed to shock melting of the porous iron.展开更多
In present work,EEG and BP were used as the indexes to observe the relationbetween the change of EEG and the change of BP in the endotoxic shocked rats。At maintainingshock for 1 hr,dysrhythmia of EEG appeared in 38/4...In present work,EEG and BP were used as the indexes to observe the relationbetween the change of EEG and the change of BP in the endotoxic shocked rats。At maintainingshock for 1 hr,dysrhythmia of EEG appeared in 38/46 cases.Simultaneously,there was a markeddrop in Bp,P【0.05.Following the shocked time prolonged,dysrhythmia was getting severe。AfterEA”Rengzhong"(n=14)or“Zusanli”(n=12),BP was significantly increased(P【0.05),anddysrhythmia of EEG showed clear improvement in most of the rats。There was a close relation be-tween the changes of EEG and BP,the change of EEG had a direct bearing on the change of BP.展开更多
The latest applications of laser shock processing were summarized in this paper,and laser peening with water confined layer has been applied to Ti6Al4V titanium alloy using Nd:glass pulse laser.The profile of plastic ...The latest applications of laser shock processing were summarized in this paper,and laser peening with water confined layer has been applied to Ti6Al4V titanium alloy using Nd:glass pulse laser.The profile of plastic deformation and residual stresses on metal surface were studied with different laser power density.The investigation results show that peak depth of plastic deformation is in linear proportion to laser power density(5.75GW/cm2 to 9.5 GW/cm2),and maximal surface compressive residual stress is up to 375MPa at 8.25GW/cm2.It was ensured that the compressive residual stress field related to laser power density and shocked times.As spot overlapping ratio of 33%,the circle spot can get a relative smooth surface.Almen strip with thickness 2.5mm was shocked as the preliminary verification test of residual stresses,and it is shown that excessive peening times is unavailable to thin-wall parts just as edge of fan blades.展开更多
We present a numerical framework for simulating viscous compressible flows in the presence of solid particles with large size ratios.The volume-filtered Navier-Stokes equations are discretized using a class of high-or...We present a numerical framework for simulating viscous compressible flows in the presence of solid particles with large size ratios.The volume-filtered Navier-Stokes equations are discretized using a class of high-order low-dissipative finite difference operators with energy-preserving properties.No-slip,adiabatic boundary conditions are enforced at the surface of large particles(with diameters significantly larger than the local grid spacing)using a ghost-point immersed boundary method.Two-way coupling between the gas phase and small particles(with diameters proportional to the grid spacing)is accounted for through volumetric source terms for interphase momentum and energy exchange.A simple and efficient approach for collision detection between small and large particles is proposed.The framework is applied to simulations of planar shocks interacting with bidisperse distributions of particles with size ratios of approximately thirty.Particle dispersion and size segregation are reported and a simple analytical model for size segregation is proposed.展开更多
The damage evolution of polycrystalline Al with helium(He)bubbles under strongly decaying shock waves is studied by molecular dynamics simulations.A new damage region is observed near the loading side of the sample,an...The damage evolution of polycrystalline Al with helium(He)bubbles under strongly decaying shock waves is studied by molecular dynamics simulations.A new damage region is observed near the loading side of the sample,and the evolution characteristics and underlying mechanisms are elucidated.The development of damage in the new damage region begins after complete unloading of the incident shock wave and is further enhanced when the tensile stress arrives later.The damage evolution is completely controlled by the expansion-merging of He bubbles,without nucleation–growth of voids.This new damage region can be divided into two sections,each of which exhibits a unique dominant mechanism.The damage in the section closer to the loading side is due to the reverse velocity gradient formed after complete unloading of the incident shock wave,depending on the rate of decrease and the amplitude of the initial peak pressure.A high initial peak pressure that can lead to melting of material near the loading side is a necessary condition for the formation of the new damage region,since a significant reverse velocity gradient can only be established if melting occurs.The dominant mechanism in the section distant from the loading side is the action of tensile stress,associated with the profile of the incident shock wave upon reaching the free surface,which determines the material phase near the free surface.Moreover,the presence of He bubbles is another critical factor for formation of the new damage region,which does not occur in pure Al samples.展开更多
As a multidisciplinary phenomenon,panel aeroelasticity in shock-dominated flow is featured by two primary interactions:Fluid-Structure Interactions(FSIs)and Shock-Boundary Layer Interactions(SBLIs).The former raises s...As a multidisciplinary phenomenon,panel aeroelasticity in shock-dominated flow is featured by two primary interactions:Fluid-Structure Interactions(FSIs)and Shock-Boundary Layer Interactions(SBLIs).The former raises structural concerns,and the latter is of aerodynamic interest.Thus,panel aeroelasticity in shock-dominated flow represents a vital topic for the development and optimization of supersonic vehicles and propulsion systems.This review systematically summarizes recent advances in the methodologies applied to capture structural and fluid dynamics,including theoretical models,numerical simulations,and wind tunnel experiments.The application of data-driven modal decomposition,an advanced technique to extract physically crucial features,on the topic is introduced.From the perspective of FSIs,the distinctive aeroelastic behaviors in shock-dominated flow,including hysteresis phenomena and nonlinear responses,are highlighted.From the perspective of SBLIs,the modifications in their spatial and temporal characteristics imposed by the aeroelastic responses are emphasized.Motivated by the interaction between the shock waves and structural response,different strategies have been proposed to implement aeroelastic suppression and shock control,which have the potential to enhance structural safety and aerodynamic performance in the next generation of high-speed flight vehicles.展开更多
Investigating the damage evolution of surrounding rock under thermal shock cycles is crucial for ensuring the stability of engineering rock masses.This study performed Brazilian splitting tests on granite specimens un...Investigating the damage evolution of surrounding rock under thermal shock cycles is crucial for ensuring the stability of engineering rock masses.This study performed Brazilian splitting tests on granite specimens under varying temperature and cycle conditions,employing acoustic emission monitoring,digital image correlation,and three-dimensional scanning technology.A systematic analysis was conducted on the patterns of damage evolution,failure precursor,and response mechanisms under combined thermal and cyclic loading.Experimental results show that both P-wave velocity and tensile strength degrade significantly with increasing temperature and cycle count,with temperature having a more pronounced effect than cycle count.Notably,damage evolution exhibits a dual-threshold behavior in which degradation accelerates markedly above 400℃ and stabilizes after 5 thermal cycles.Fracture surfaces evolve from initially planar to rugged morphologies,with peak-valley height differences at 600℃ being approximately three times greater than those at 200℃.Furthermore,based on acoustic emission energy entropy analysis,we introduce a novel failure precursor indicator where the sustained increase and critical surge in average entropy serve as reliable early-warning signals for impending rock failure.These findings establish a solid theoretical basis and practical methodology for damage assessment and instability early-warning systems in high-temperature rock engineering.展开更多
For hypersonic air-breathing vehicles,the V-shaped leading edges(VSLEs)of supersonic combustion ramjet(scramjet)inlets experience complex shock interactions and intense aerodynamic loads.This paper provides a comprehe...For hypersonic air-breathing vehicles,the V-shaped leading edges(VSLEs)of supersonic combustion ramjet(scramjet)inlets experience complex shock interactions and intense aerodynamic loads.This paper provides a comprehensive review of flow characteristics at the crotch of VSLEs,with particular focus on the transition of shock interaction types and the variation of wall heat flux under different freestream Mach numbers and geometric configurations.The mechanisms governing shock transition,unsteady oscillations,hysteresis,and three-dimensional effects in VSLE flows are first examined.Subsequently,thermal protection strategies aimed at mitigating extreme heating loads are reviewed,emphasizing their relevance to practical engineering applications.Special attention is given to recent studies addressing thermochemical nonequilibrium effects on VSLE shock interactions,and the limitations of current research are critically assessed.Finally,perspectives for future investigations into hypersonic VSLE shock interactions are outlined,highlighting opportunities for advancing design and thermal management strategies.展开更多
Coal-derived hard carbon(HC)represents a promising anode material for sodium-ion batteries owing to its cost-effectiveness and high carbon yield.However,conventional carbonization induces excessive graphitization,yiel...Coal-derived hard carbon(HC)represents a promising anode material for sodium-ion batteries owing to its cost-effectiveness and high carbon yield.However,conventional carbonization induces excessive graphitization,yielding insufficient interlayer spacing(d_(002)<0.37 nm)and underdeveloped closed pores.Herein,we propose a dynamic crystallization control strategy through carbothermal shock treatment(1300°C,30 s)that decouples thermodynamic and kinetic constraints.This method precisely modulates graphite domain ordering kinetics,producing short-range ordered structures with expanded interlayer spacing(d_(002)=0.385 nm)and homogeneously distributed closed nanopores.Through combined in situ characterization and first-principles calculations,we elucidate a three-stage crystallization mechanism:(i)amorphous carbon transformation,(ii)open-pore collapse,and(iii)pseudo-graphitic ordering.The optimized HC achieves record performance with 88.6%initial Coulombic efficiency and 204 mA h g^(−1)plateau capacity,while its optimal interlayer spacing lowers Na+diffusion barriers to enable exceptional rate capability(221 mA h g^(−1)at 0.5C after 300 cycles).Practical pouch cells maintain 85%capacity retention after 100 cycles at−20°C and deliver 284 Wh kg^(−1)energy density.This work establishes a kinetic regulation paradigm for graphitization-prone precursors,advancing the rational design of high-performance HC anodes.展开更多
Tellurene,a chiral chain semiconductor with a narrow bandgap and exceptional strain sensitivity,emerges as a pivotal material for tailoring electronic and optoelectronic properties via strain engineering.This study el...Tellurene,a chiral chain semiconductor with a narrow bandgap and exceptional strain sensitivity,emerges as a pivotal material for tailoring electronic and optoelectronic properties via strain engineering.This study elucidates the fundamental mechanisms of ultrafast laser shock imprinting(LSI)in two-dimensional tellurium(Te),establishing a direct relationship between strain field orientation,mold topology,and anisotropic structural evolution.This is the first demonstration of ultrafast LSI on chiral chain Te unveiling orientation-sensitive dislocation networks.By applying controlled strain fields parallel or transverse to Te’s helical chains,we uncover two distinct deformation regimes.Strain aligned parallel to the chain’s direction induces gliding and rotation governed by weak interchain interactions,preserving covalent intrachain bonds and vibrational modes.In contrast,transverse strain drives shear-mediated multimodal deformations—tensile stretching,compression,and bending—resulting in significant lattice distortions and electronic property modulation.We discovered the critical role of mold topology on deformation:sharp-edged gratings generate localized shear forces surpassing those from homogeneous strain fields via smooth CD molds,triggering dislocation tangle formation,lattice reorientation,and inhomogeneous plastic deformation.Asymmetrical strain configurations enable localized structural transformations while retaining single-crystal integrity in adjacent regions—a balance essential for functional device integration.These insights position LSI as a precision tool for nanoscale strain engineering,capable of sculpting 2D material morphologies without compromising crystallinity.By bridging ultrafast mechanics with chiral chain material science,this work advances the design of strain-tunable devices for next-generation electronics and optoelectronics,while establishing a universal framework for manipulating anisotropic 2D systems under extreme strain rates.This work discovered crystallographic orientation-dependent deformation mechanisms in 2D Te,linking parallel strain to chain gliding and transverse strain to shear-driven multimodal distortion.It demonstrates mold geometry as a critical lever for strain localization and dislocation dynamics,with sharp-edged gratings enabling unprecedented control over lattice reorientation.Crucially,the identification of strain field conditions that reconcile severe plastic deformation with single-crystal retention offers a pathway to functional nanostructure fabrication,redefining LSI’s potential in ultrafast strain engineering of chiral chain materials.展开更多
Structural engineering of Pt-based nanoalloys is crucial for the rational design and manufacturing of high-performance and low-cost electrocatalysts for hydrogen evolution reaction(HER).Here,we reported PtNi nanoparti...Structural engineering of Pt-based nanoalloys is crucial for the rational design and manufacturing of high-performance and low-cost electrocatalysts for hydrogen evolution reaction(HER).Here,we reported PtNi nanoparticles with a refined size of 2.71 nm and regular strains loaded on carbon black,synthesized using the high-temperature liquid shock(HTLS)method.This approach offers significant advantages over conventional synthesis methods,including high scalability,rapid reaction rates,and precise control over the size and shape of nanocrystals.Importantly,the synthesized PtNi electrocatalysts demonstrate outstanding catalytic activity and long-term stability for HER,achieving low overpotentials of 19 and 203 mV at current densities of 10 and 1000 mA/cm^(2),respectively.The superior performance can be attributed to the combination of a refined particle size,lattice strains,and synergistic effects between Pt and Ni.This rapid liquid-state synthesis demonstrated here holds great potential for scalable and industrial manufacturing of micro-/nano-catalysts.展开更多
Stator vanes especially vane suction sides of transonic turbines are subjected to high frequency excitation forces under many circumstances,and thus are exposed to the risk of high cycle fatigue.Therefore,it is necess...Stator vanes especially vane suction sides of transonic turbines are subjected to high frequency excitation forces under many circumstances,and thus are exposed to the risk of high cycle fatigue.Therefore,it is necessary to reveal the flow mechanism of this kind of excitations for potential prevention measures.In this paper,the traveling shock phenomenon in the transonic turbine stator/rotor gap is observed and the concept of‘Inter-Row Traveling Shock(IRTS)'is proposed through the unsteady Reynolds-Averaged Navier-Stokes(RANS)simulation of a typical highlyloaded transonic turbine stage.The characteristics of an IRTS were described and summarized in aspects of unsteady shock wave system,aerodynamic characteristics and motion.The probable forming mechanism of an IRTS was explained through a theoretical model and it was validated through correct prediction of the flow state parameter change across the IRTS.Since IRTSs would strike onto vane suction sides,the pressure oscillation dynamic modes on vane suction side corresponding to the characteristic frequencies associated with IRTS were extracted through Dynamic Mode Decomposition(DMD),from which the way and extent of the IRTS influences on vane aerodynamic excitation were revealed and evaluated.Over 82%pressure oscillation energy on vane suction side could be brought by the IRTS sweeping along with blade rotation.展开更多
基金Science and Technology Planning Project of Guangdong Province,2023B1212060048,Xiande Xie。
文摘Recovered samples of Jilin H5 chondrite experimentally shocked to 12-133 GPa were studied to explore the behavior of opaque minerals under shock loading using SEM-EDS,Raman spectroscopy,and TIMA.The following results were obtained.Firstly,at pressures lower than 53GPa,the opaque minerals still keep the unmelted state,while at 78 GPa and higher,FeNi metal and troilite form eutectic intergrowths occurring as disorderly fine veinlets filling the shock-induced fractures in silicate minerals.Secondly,single kamacite grains still maintain their contour at 12 GPa,but a part of brittle troilite grains was fragmented and squeezed into the shock-induced fractures within kamacite grains.At53 and 133 GPa,many more troilite fragments are poured in the kamacite interior to form disordered hybrid aggregates or to form squiggly strips,respectively.Similar phenomena are observed within single troilite grains,but the mineral squeezed into troilite grains is kamacite.Thirdly,chromite is a hard and refractory oxide mineral.When the shock pressure rises step by step from 12 to 133 GPa,the shock effect of chromite is only fragmentation.Its grain size decreases from tens of um at 53 GPa to a few um at 133 GPa.And,fourthly,native copper exhibits distinct redistribution behavior at high temperature.In Jilin samples shock-loaded to 12 GPa,copper initially located at troilite-kamacite interfaces partially transferred into small troilite grains containing fine FeNi particles.At 53 and 133 GPa,native copper preferentially transferred into larger troilite grains containing more particles of eutectic FeNi metal.
基金the National Natural Science Foundation of China(Grant No.11604271).
文摘The phase transition behaviors of the shocked water are investigated by employing an optical transmittance in-situ detection system.Based on the light scattering theory and phase transformation kinetics,the phase transition mechanism of the water under multiple shocks is discussed.The experimental data indicate that the evolution of the transmittance of the shocked water can be broadly divided into three stages:relaxation stage,decline stage,and recovery stage.In the early stage of the phase transition,the new phase particles began to form around the quartz/window interface.It should be mentioned that the water/ice phase boundary seems to move toward the liquid region in one experiment of this work.Due to the new phase core being much smaller than the wavelength of the incident light,the transmittance of the sample within the relaxation stage remains steady.The decline stage can be divided into the rapid descent stage and the slow descent stage in this work,which is considered as the different growth rates of the new phase particle under different shock loadings.The recovery stage is attributed to the emergence of the new phase particles which are bigger than the critical value.However,the influence of the size growth and the population growth of the new phase particles on the transmittance restrict each other,which may be responsible for the phenomenon that the transmittance curve does not return to the initial level.
文摘We have calculated the Hugoniot properties of shocked nitromethane based on the improved Tsien＇s equa- tion of state （EOS） that optimized by ＂exact＂ numerical molecular dynamic data at high temperatures and pressures. Comparison of the calculated results of the improved Tsien＇s EOS with the existed experimental data and the direct simu- lations show that the behavior of the improved Tsien＇s EOS is very good in many aspects. Because of its simple analytical form, the improved Tsien＇s EOS can be prospectively used to study the condensed explosive detonation coupling with chemical reaction.
文摘Raman spectra of liquid nitromethane were measured in single-shock experiments using transient Raman scattering system with high sensitivity. The measurement system was combined with a two-stage light gas gun to interrogate the vibrational mode-dependent behaviors of shock-compressed nitromethane molecules. Up to 12 GPa, all Raman peaks were able to be clearly detected, and showed the shock-induced shifting and broadening, but no signs of chemical changes occurred in the sample. Thus, it is concluded that chemical reactions could not be initiated in singly-shocked nitromethane below 12 GPa.
基金Supported by the Natural Science Foundation of Shaanxi Province,No.2004C271
文摘AIM. To study whether heat-shocked tumor cells could enhance the effect of tumor cell lysate-pulsed dendritic cells （DCs） in evoking anti-tumor immune response in vivo. METHODS： Mouse undifferentiated colon cancer cells （CT-26） were heated at 42℃ for 1 h and then frozenthawed. The bone marrow-derived DCs pulsed with heatshocked CT-26 cell lysate （HSCT-26 DCs） were recruited to immunize syngeneic naive BALB/c mice. The cytotoxic activity of tumor specific cytotoxic T lymphocytes （CTLs） in mouse spleen was evaluated by IFN-enzyme-linked immunospot （ELISpot） and LDH release assay. The immunoprophylactic effects induced by HSCT-26 DCs in mouse colon cancer model were compared to those induced by single CT-26 cell lysate-pulsed DCs （CT-26 DCs） on tumor volume, peritoneal metastasis and survival time of the mice. RESULTS： Heat-treated CT-26 cells showed a higher hsp70 protein expression. Heat-shocked CT-26 cell lysate pulsing elevated the co-stimulatory and MHC-Ⅱ molecule expression of bone marrow-derived DCs as well as interleukin-12 p70 secretion. The IFN-y secreting CTLs induced by HSCT-26 DCs were significantly more than those induced by CT-26 DCs （P=0.002）. The former CTLs＇ specific cytotoxic activity was higher than the latter CTLs＇ at a serial E/T ratio of 10：1, 20：1, and 40：1. Mouse colon cancer model showed that the tumor volume of HSCT-26 DC vaccination group was smaller than that of CT-26 DC vaccination group on tumor volume though there was no statistical difference between them （24 mm^3 vs 8 mm^3, P=0.480）. The median survival time of mice immunized with HSCT-26 DCs was longer than that of those immunized with CT-26 DCs （57 d vs 43 d, P = 0.0384）. CONCLUSION： Heat-shocked tumor cell lysate-pulsed DCs can evoke anti-tumor immune response in vivo effectively and serve as a novel DC-based tumor vaccine.
文摘We apply a hydrodynamic approach to analyze ejecta emanating from doubly shocked liquid metals. In particular, we are interested incharacterizing ejecta velocities in such situations by treating the problem as a limiting case of the Richtmyer–Meshkov instability. We findexisting models for ejecta velocities do not adequately capture all the relevant physics, including compressibility, nonlinearities, and nonstandardshapes. We propose an empirical model that is capable of describing ejecta behavior across the entire parameter range of interest. We thensuggest a protocol to apply this model when the donor material is shocked twice in rapid succession. Finally, the model and the suggestedapproach are validated using detailed continuum hydrodynamic simulations. The results provide a baseline understanding of the hydrodynamicaspects of ejecta, which can then be used to interpret experimental data from target experiments.
基金supported by Science and Technology Planning Project of Guangdong Province,2023B1212060048.
文摘Copper possesses very strong chacophile properties,but under the conditions found in meteorites,its behavior is like that of siderophile elements.The Suizhou meteorite is a highly shocked L6 chondrite.Troilite and taenite are considered the main primary carrier of copper in this meteorite,and the post-shock thermal episode is considered the main reason that elemental Cu migrates from its original host phase and forms metallic grains.The Suizhou meteorite contains a few very thin shock melt veins.The occurrence and behavior of metallic copper in this meteorite were studied by optical microscopic examination,electron microprobe analyses,and high-resolution X-ray elemental intensity mapping.Our results show that metallic copper is abundant in the Suizhou chondritic rock.Metallic copper grains adjacent to small troilite grains inside FeNi metal are the most common occurrence,and those at the FeNi metal–troilite interface are the second most common case.The metallic copper grains occurring at the interface of FeNi metal/troililte and silicate are rather rare.Metallic copper grains are not observed within the Suizhou shock veins,Instead,Cu in elemental form is transferred through shock metamorphism into FeNi metal+troilite intergrowths.Four diff erent occurrence types of Cu in the FeNi metal+troilite intergrowths have been identifi ed:the concentrations of Cu in the FeNi+FeS intergrowths for four occurrence types are rather close,we estimate it might be lower than 1 wt%.
基金supported by the National Natural Science Foundation of China(Grant Nos.11472254 and 11272006)
文摘We conduct molecular dynamics simulations of the ejection process from a grooved Pb surface subjected to supported and unsupported shock waves with various shock-breakout pressures（PSB） inducing a solid–liquid phase transition upon shock or release. It is found that the total ejecta mass changing with PSBunder a supported shock reveals a similar trend with that under an unsupported shock and the former is always less than the latter at the same PSB. The origin of such a discrepancy could be unraveled that for an unsupported shock, a larger velocity difference between the jet tip and its bottom at an early stage of jet formation results in more serious damage, and therefore a greater amount of ejected particles are produced. The cumulative areal density distributions also display the discrepancy. In addition, we discuss the difference of these simulated results compared to the experimental findings.
基金Supported by the National Natural Science Foundation of China under Grant No.10032040。
文摘Sound velocities in shock-loaded solids are not only important to determine bulk moduli of solids at high pressures, but are also crucial to inform the shock melting of solids upon loading. In this letter, we first report on shock melting of porous solids at high pressures by measuring sound velocities in the porous iron of average density 6.90 g/cm^(3) in the pressure range of 110-180 GPa. The measured sound velocity softens at pressures from 122 to 156 Gpa, which may be attributed to shock melting of the porous iron.
基金The Project Supported by National Natural Science Foundation of China
文摘In present work,EEG and BP were used as the indexes to observe the relationbetween the change of EEG and the change of BP in the endotoxic shocked rats。At maintainingshock for 1 hr,dysrhythmia of EEG appeared in 38/46 cases.Simultaneously,there was a markeddrop in Bp,P【0.05.Following the shocked time prolonged,dysrhythmia was getting severe。AfterEA”Rengzhong"(n=14)or“Zusanli”(n=12),BP was significantly increased(P【0.05),anddysrhythmia of EEG showed clear improvement in most of the rats。There was a close relation be-tween the changes of EEG and BP,the change of EEG had a direct bearing on the change of BP.
文摘The latest applications of laser shock processing were summarized in this paper,and laser peening with water confined layer has been applied to Ti6Al4V titanium alloy using Nd:glass pulse laser.The profile of plastic deformation and residual stresses on metal surface were studied with different laser power density.The investigation results show that peak depth of plastic deformation is in linear proportion to laser power density(5.75GW/cm2 to 9.5 GW/cm2),and maximal surface compressive residual stress is up to 375MPa at 8.25GW/cm2.It was ensured that the compressive residual stress field related to laser power density and shocked times.As spot overlapping ratio of 33%,the circle spot can get a relative smooth surface.Almen strip with thickness 2.5mm was shocked as the preliminary verification test of residual stresses,and it is shown that excessive peening times is unavailable to thin-wall parts just as edge of fan blades.
基金This work used Expanse systems at UCSD through an allocation[PHY240089]from the Advanced Cyberinfrastructure Coordination Ecosystem:Services&Support(ACCESS)programsupported by U.S.National Science Foundation(Grant Nos.2138259,2138286,2138307,2137603 and 2138296).
文摘We present a numerical framework for simulating viscous compressible flows in the presence of solid particles with large size ratios.The volume-filtered Navier-Stokes equations are discretized using a class of high-order low-dissipative finite difference operators with energy-preserving properties.No-slip,adiabatic boundary conditions are enforced at the surface of large particles(with diameters significantly larger than the local grid spacing)using a ghost-point immersed boundary method.Two-way coupling between the gas phase and small particles(with diameters proportional to the grid spacing)is accounted for through volumetric source terms for interphase momentum and energy exchange.A simple and efficient approach for collision detection between small and large particles is proposed.The framework is applied to simulations of planar shocks interacting with bidisperse distributions of particles with size ratios of approximately thirty.Particle dispersion and size segregation are reported and a simple analytical model for size segregation is proposed.
基金supported by the National Natural Science Foundation of China(Grant No.12172063).
文摘The damage evolution of polycrystalline Al with helium(He)bubbles under strongly decaying shock waves is studied by molecular dynamics simulations.A new damage region is observed near the loading side of the sample,and the evolution characteristics and underlying mechanisms are elucidated.The development of damage in the new damage region begins after complete unloading of the incident shock wave and is further enhanced when the tensile stress arrives later.The damage evolution is completely controlled by the expansion-merging of He bubbles,without nucleation–growth of voids.This new damage region can be divided into two sections,each of which exhibits a unique dominant mechanism.The damage in the section closer to the loading side is due to the reverse velocity gradient formed after complete unloading of the incident shock wave,depending on the rate of decrease and the amplitude of the initial peak pressure.A high initial peak pressure that can lead to melting of material near the loading side is a necessary condition for the formation of the new damage region,since a significant reverse velocity gradient can only be established if melting occurs.The dominant mechanism in the section distant from the loading side is the action of tensile stress,associated with the profile of the incident shock wave upon reaching the free surface,which determines the material phase near the free surface.Moreover,the presence of He bubbles is another critical factor for formation of the new damage region,which does not occur in pure Al samples.
基金supported by the National Natural Science Foundation of China(No.12372233)the Innovation Foundation for Doctor Dissertation of Northwestern Polytechnical University,China(No.25GH01020005)the“111 Project”of China(No.B17037)。
文摘As a multidisciplinary phenomenon,panel aeroelasticity in shock-dominated flow is featured by two primary interactions:Fluid-Structure Interactions(FSIs)and Shock-Boundary Layer Interactions(SBLIs).The former raises structural concerns,and the latter is of aerodynamic interest.Thus,panel aeroelasticity in shock-dominated flow represents a vital topic for the development and optimization of supersonic vehicles and propulsion systems.This review systematically summarizes recent advances in the methodologies applied to capture structural and fluid dynamics,including theoretical models,numerical simulations,and wind tunnel experiments.The application of data-driven modal decomposition,an advanced technique to extract physically crucial features,on the topic is introduced.From the perspective of FSIs,the distinctive aeroelastic behaviors in shock-dominated flow,including hysteresis phenomena and nonlinear responses,are highlighted.From the perspective of SBLIs,the modifications in their spatial and temporal characteristics imposed by the aeroelastic responses are emphasized.Motivated by the interaction between the shock waves and structural response,different strategies have been proposed to implement aeroelastic suppression and shock control,which have the potential to enhance structural safety and aerodynamic performance in the next generation of high-speed flight vehicles.
基金supported by National Natural Science Foundation of China (Nos.52264006,52364004,and 52464005)the Guizhou Provincial Science and Technology Foundation (No.GCC[2022]005-1)。
文摘Investigating the damage evolution of surrounding rock under thermal shock cycles is crucial for ensuring the stability of engineering rock masses.This study performed Brazilian splitting tests on granite specimens under varying temperature and cycle conditions,employing acoustic emission monitoring,digital image correlation,and three-dimensional scanning technology.A systematic analysis was conducted on the patterns of damage evolution,failure precursor,and response mechanisms under combined thermal and cyclic loading.Experimental results show that both P-wave velocity and tensile strength degrade significantly with increasing temperature and cycle count,with temperature having a more pronounced effect than cycle count.Notably,damage evolution exhibits a dual-threshold behavior in which degradation accelerates markedly above 400℃ and stabilizes after 5 thermal cycles.Fracture surfaces evolve from initially planar to rugged morphologies,with peak-valley height differences at 600℃ being approximately three times greater than those at 200℃.Furthermore,based on acoustic emission energy entropy analysis,we introduce a novel failure precursor indicator where the sustained increase and critical surge in average entropy serve as reliable early-warning signals for impending rock failure.These findings establish a solid theoretical basis and practical methodology for damage assessment and instability early-warning systems in high-temperature rock engineering.
基金funded by the Research Fund of National Key Laboratory of Aerospace Physics in Fluids,grant number 2024-APF-KFZD-01Guangdong Basic and Applied Basic Research Foundation,grant number 2025A1515012081+1 种基金National Natural Science Foundation of China,grant number 12002193Shandong Provincial Natural Science Foundation,China,grant number ZR2019QA018.
文摘For hypersonic air-breathing vehicles,the V-shaped leading edges(VSLEs)of supersonic combustion ramjet(scramjet)inlets experience complex shock interactions and intense aerodynamic loads.This paper provides a comprehensive review of flow characteristics at the crotch of VSLEs,with particular focus on the transition of shock interaction types and the variation of wall heat flux under different freestream Mach numbers and geometric configurations.The mechanisms governing shock transition,unsteady oscillations,hysteresis,and three-dimensional effects in VSLE flows are first examined.Subsequently,thermal protection strategies aimed at mitigating extreme heating loads are reviewed,emphasizing their relevance to practical engineering applications.Special attention is given to recent studies addressing thermochemical nonequilibrium effects on VSLE shock interactions,and the limitations of current research are critically assessed.Finally,perspectives for future investigations into hypersonic VSLE shock interactions are outlined,highlighting opportunities for advancing design and thermal management strategies.
基金supported by the Key Laboratory of Sichuan Province for Lithium Resources Comprehensive Utilization and New Lithium Based Materials for Advanced Battery Technology(LRMKF202405)the National Natural Science Foundation of China(52402226)the Natural Science Foundation of Sichuan Province(2024NSFSC1016).
文摘Coal-derived hard carbon(HC)represents a promising anode material for sodium-ion batteries owing to its cost-effectiveness and high carbon yield.However,conventional carbonization induces excessive graphitization,yielding insufficient interlayer spacing(d_(002)<0.37 nm)and underdeveloped closed pores.Herein,we propose a dynamic crystallization control strategy through carbothermal shock treatment(1300°C,30 s)that decouples thermodynamic and kinetic constraints.This method precisely modulates graphite domain ordering kinetics,producing short-range ordered structures with expanded interlayer spacing(d_(002)=0.385 nm)and homogeneously distributed closed nanopores.Through combined in situ characterization and first-principles calculations,we elucidate a three-stage crystallization mechanism:(i)amorphous carbon transformation,(ii)open-pore collapse,and(iii)pseudo-graphitic ordering.The optimized HC achieves record performance with 88.6%initial Coulombic efficiency and 204 mA h g^(−1)plateau capacity,while its optimal interlayer spacing lowers Na+diffusion barriers to enable exceptional rate capability(221 mA h g^(−1)at 0.5C after 300 cycles).Practical pouch cells maintain 85%capacity retention after 100 cycles at−20°C and deliver 284 Wh kg^(−1)energy density.This work establishes a kinetic regulation paradigm for graphitization-prone precursors,advancing the rational design of high-performance HC anodes.
基金financial support from NSF ExpandQISE program.The synthesis of tellurene was supported by NSF under grant no.CMMI-2046936supports from Purdue Research Foundation.
文摘Tellurene,a chiral chain semiconductor with a narrow bandgap and exceptional strain sensitivity,emerges as a pivotal material for tailoring electronic and optoelectronic properties via strain engineering.This study elucidates the fundamental mechanisms of ultrafast laser shock imprinting(LSI)in two-dimensional tellurium(Te),establishing a direct relationship between strain field orientation,mold topology,and anisotropic structural evolution.This is the first demonstration of ultrafast LSI on chiral chain Te unveiling orientation-sensitive dislocation networks.By applying controlled strain fields parallel or transverse to Te’s helical chains,we uncover two distinct deformation regimes.Strain aligned parallel to the chain’s direction induces gliding and rotation governed by weak interchain interactions,preserving covalent intrachain bonds and vibrational modes.In contrast,transverse strain drives shear-mediated multimodal deformations—tensile stretching,compression,and bending—resulting in significant lattice distortions and electronic property modulation.We discovered the critical role of mold topology on deformation:sharp-edged gratings generate localized shear forces surpassing those from homogeneous strain fields via smooth CD molds,triggering dislocation tangle formation,lattice reorientation,and inhomogeneous plastic deformation.Asymmetrical strain configurations enable localized structural transformations while retaining single-crystal integrity in adjacent regions—a balance essential for functional device integration.These insights position LSI as a precision tool for nanoscale strain engineering,capable of sculpting 2D material morphologies without compromising crystallinity.By bridging ultrafast mechanics with chiral chain material science,this work advances the design of strain-tunable devices for next-generation electronics and optoelectronics,while establishing a universal framework for manipulating anisotropic 2D systems under extreme strain rates.This work discovered crystallographic orientation-dependent deformation mechanisms in 2D Te,linking parallel strain to chain gliding and transverse strain to shear-driven multimodal distortion.It demonstrates mold geometry as a critical lever for strain localization and dislocation dynamics,with sharp-edged gratings enabling unprecedented control over lattice reorientation.Crucially,the identification of strain field conditions that reconcile severe plastic deformation with single-crystal retention offers a pathway to functional nanostructure fabrication,redefining LSI’s potential in ultrafast strain engineering of chiral chain materials.
基金supported by the National Natural Science Foundation of China(No.12205165)Hebei Province Innovation Ability Improvement Plan Project(No.225676111H).
文摘Structural engineering of Pt-based nanoalloys is crucial for the rational design and manufacturing of high-performance and low-cost electrocatalysts for hydrogen evolution reaction(HER).Here,we reported PtNi nanoparticles with a refined size of 2.71 nm and regular strains loaded on carbon black,synthesized using the high-temperature liquid shock(HTLS)method.This approach offers significant advantages over conventional synthesis methods,including high scalability,rapid reaction rates,and precise control over the size and shape of nanocrystals.Importantly,the synthesized PtNi electrocatalysts demonstrate outstanding catalytic activity and long-term stability for HER,achieving low overpotentials of 19 and 203 mV at current densities of 10 and 1000 mA/cm^(2),respectively.The superior performance can be attributed to the combination of a refined particle size,lattice strains,and synergistic effects between Pt and Ni.This rapid liquid-state synthesis demonstrated here holds great potential for scalable and industrial manufacturing of micro-/nano-catalysts.
文摘Stator vanes especially vane suction sides of transonic turbines are subjected to high frequency excitation forces under many circumstances,and thus are exposed to the risk of high cycle fatigue.Therefore,it is necessary to reveal the flow mechanism of this kind of excitations for potential prevention measures.In this paper,the traveling shock phenomenon in the transonic turbine stator/rotor gap is observed and the concept of‘Inter-Row Traveling Shock(IRTS)'is proposed through the unsteady Reynolds-Averaged Navier-Stokes(RANS)simulation of a typical highlyloaded transonic turbine stage.The characteristics of an IRTS were described and summarized in aspects of unsteady shock wave system,aerodynamic characteristics and motion.The probable forming mechanism of an IRTS was explained through a theoretical model and it was validated through correct prediction of the flow state parameter change across the IRTS.Since IRTSs would strike onto vane suction sides,the pressure oscillation dynamic modes on vane suction side corresponding to the characteristic frequencies associated with IRTS were extracted through Dynamic Mode Decomposition(DMD),from which the way and extent of the IRTS influences on vane aerodynamic excitation were revealed and evaluated.Over 82%pressure oscillation energy on vane suction side could be brought by the IRTS sweeping along with blade rotation.
