An evolving material structure is in a non-equilibrium state, with free energy expressed by the generalized coordinates. A global approach leads to robust computations for the generalized thermodynamic forces. Those f...An evolving material structure is in a non-equilibrium state, with free energy expressed by the generalized coordinates. A global approach leads to robust computations for the generalized thermodynamic forces. Those forces drive various kinetic processes, causing dissipation at spots, along curves, surfaces and interfaces, and within volumetric regions. The actual evolution path, and therefore the final equilibrium state, is determined by the energetics and kinetics. A virtual work principle Links the free energy landscape and the kinetic processes, and assigns a viscous environment to every point on the landscape. The approach leads to a dynamical system that governs the evolution of generalized coordinates. The microstructural evolution is globally characterized by a basin map in the coordinate space; and by a diversity map and a variety map in the parameter space. The control of basin boundaries raises the issue of energetic and kinetic bifurcations. The variation of basin boundaries under different sets of controlling parameters provides an analytical way to plot the diversity maps of structural evolution.展开更多
There are several basins with high sediment yield in the Pisha-sandstone covering area of the east wing of the Ordos Plateau. Due to the lack of targeted research on the dynamical characteristics of geomorphic evoluti...There are several basins with high sediment yield in the Pisha-sandstone covering area of the east wing of the Ordos Plateau. Due to the lack of targeted research on the dynamical characteristics of geomorphic evolution that plays an important role in the sand production, this paper analyzed the tectonic activity intensity and erosion characteristics of the area. The results show that the intensity of tectonic activities in the area is generally moderateweak and shows an unconspicuous increase from north to south. Tectonic activity is manifested mainly in the form of uplift. The uplift rate in the lower reaches of each basin is greater than the erosion rate,which is prominent in the Kuyehe and the Tuweihe rivers. During the uplift of the regional topography,the most serious parts under erosion are generally concentrated in the upstream and midstream of basins. All longitudinal profiles of the basins have a shape close to an exponential function, which indicates that they are in the early stage of erosion evolution. The mechanisms of geomorphologic evolution of these basins have a great similarity. The conservative estimate of historical average erosion rate was less than 182–520 t/(km^2·yr), much less than that of the modern times. The average stream power values are typically distributed between 4 and102 W/m, with the larger being in the Kuyehe and the Tuweihe rivers and the smallest being in the Qinshuihe River. The maximum stream power value appears in the downstream reach, which should be the main reason for the particles being directly injected into the Yellow River. From the perspective of geomorphological evolution, the current soil and water conservation measures can hardly cure the erosion of these basins in the long run.展开更多
A pair of flumes with variable inclinations were employed to investigate the entrainment mechanics and dynamical evolution of a debris avalanche/flow. A fixed quantity of solid and water mixture was released from a co...A pair of flumes with variable inclinations were employed to investigate the entrainment mechanics and dynamical evolution of a debris avalanche/flow. A fixed quantity of solid and water mixture was released from a constant elevation and accelerated along a higher chute to impact substrate materials with different water contents and particle size distributions in the lower chute. Two high-speed cameras, pore and earth pressure detecting devices, were placed in the substrate materials where severe scouring occurs in order to collect multiple measurements of dynamical and mechanical parameters. The entrainment dynamics were verified by geometrical analysis and quasi-static simulation. The results show that wet and fine materials that are placed in the lower chute with steeper slopes are easily entrained during debris flow initiation, the pattern of which can be described by Coulomb friction and the Mohr-Coulomb law. Elaborate measurements of dynamical parameters enable the results of an elementary computational framework to predict the time-dependent scouring depth ht, which provides insight into rapidly determining debris flow propagation. Finally, the post-entrainment dynamics were studied. The results indicate that the propagation and the amplification of debris flows along erodible beds are dominated by the velocity and the solid volume fraction of the mixed substrate, and the coarse particle group of the substrate is a key feature affected by momentum changes.展开更多
This paper investigates the dynamical instability and adiabatic evolution of the atom homonuclear-trimer dark state of a condensate system in a stimulated Raman adiabatic passage aided by Feshbach resonance. It obtain...This paper investigates the dynamical instability and adiabatic evolution of the atom homonuclear-trimer dark state of a condensate system in a stimulated Raman adiabatic passage aided by Feshbach resonance. It obtains analytically the regions for the appearance of dynamical instability caused by the interparticle interactions. Moreover, the adiabatic property of the dark state is also studied in terms of a newly defined adiabatic fidelity. It shows that the nonlinear collisions have a negative effect on the adiabaticity of the dark state and hence reduce the conversion efficiency.展开更多
We have set up a new reduced model Hamiltonian for the polariton system, in which the nonlinear interaction contains the rotating term k l （ a ＋ b ＋ ab＋） and the attractive two-mode squeezed coupling - k2 （ a ...We have set up a new reduced model Hamiltonian for the polariton system, in which the nonlinear interaction contains the rotating term k l （ a ＋ b ＋ ab＋） and the attractive two-mode squeezed coupling - k2 （ a ＋ b＋ ＋ ab ） . The dynamical evolution of this system has been solved and the nonclassical features relevant to the second-order and high-order squeezing have been obtained in an analytical form. For the first time, in contrast to the existing result, we have confirmed for the phonon field that the attractive two-mode squeezed interaction will not only result in the second-order and high-order squeezing in X-component with the time evolution, but also in time average. Furthermore, the phenomena of collapse and revival of inversion will occur as well in the time evolution of the average number of photon and phonon, as also in the second-order and high-order squeezing of photon field, particularly, in the high-order squeezing of phonon field.展开更多
This article is devoted to studying the dynamical evolution and orbital stability of compact extrasolar threeplanetary system GJ 3138. In this system, all semimajor axes are less than 0.7 au. The modeling of planetary...This article is devoted to studying the dynamical evolution and orbital stability of compact extrasolar threeplanetary system GJ 3138. In this system, all semimajor axes are less than 0.7 au. The modeling of planetary motion is performed using the averaged semi-analytical motion theory of the second order in planetary masses,which the authors construct. Unknown and known with errors orbital elements vary in allowable limits to obtain a set of initial conditions. Each of these initial conditions is applied for the modeling of planetary motion. The assumption about the stability of observed planetary systems allows to eliminate the initial conditions leading to excessive growth of the orbital eccentricities and inclinations and to identify those under which these orbital elements conserve moderate values over the whole modeling interval. Thus, it becomes possible to limit the range of possible values of unknown orbital elements and determine their most probable values in terms of stability.展开更多
We investigate the dynamics of parity-and time-reversal（PT） symmetric two-energy-level atoms in the presence of two optical and one radio-frequency fields. The strength and relative phase of fields can drive the sys...We investigate the dynamics of parity-and time-reversal（PT） symmetric two-energy-level atoms in the presence of two optical and one radio-frequency fields. The strength and relative phase of fields can drive the system from the unbroken to the broken PT symmetric regions. Compared with the Hermitian model, Rabi-type oscillation is still observed, and the oscillation characteristics are also adjusted by the strength and relative phase in the region of the unbroken symmetry. At the exception point, the oscillation breaks down. To better understand the underlying properties we study the effective Bloch dynamics and find that the emergence of the PT components of the fixed points is the feature of the PT symmetry breaking and the projections in the x–y plane can be controlled with high flexibility compared with the standard two-level system with the PT symmetry. It helps to study the dynamic behavior of the complex PT symmetric model.展开更多
The remarkable power of chemistry over description and trans-formation of matters has been significantly enhanced through the development of dynamic chemistry and condensed matter chemistry[1].This progress has furthe...The remarkable power of chemistry over description and trans-formation of matters has been significantly enhanced through the development of dynamic chemistry and condensed matter chemistry[1].This progress has further elevated chemistry to a creative science and a thriving industry.The development of dynamic chemistry,span-ning from supramolecular chemistry to constitutional dynamic chem-istry,has witnessed significant advancements towards adaptive chemistry,which is characterized primarily by its self-adaption to external stimuli.This is particularly achieved in two-or three-dimensional dynamic frameworks.Meanwhile,the multi-phase evolution resulting from the emerging of solid-to-liquid transition plat-form is assuming an increasingly crucial role in condensed matter chemistry[2].展开更多
To accurately investigate the evolution characteristics and generation mechanism of retained oil,the study analyzed organic-rich lacustrine shale samples from the Paleogene Kongdian Formation in Cangdong Sag,Bohai Bay...To accurately investigate the evolution characteristics and generation mechanism of retained oil,the study analyzed organic-rich lacustrine shale samples from the Paleogene Kongdian Formation in Cangdong Sag,Bohai Bay Basin.This analysis involves Rock-Eval pyrolysis,pyrolysis simulation experiments,Gas Chromatograph Mass Spectrometer(GC-MS),and reactive molecular dynamics simulations(ReaxFF).The results revealed the retained oil primarily consisted of n-alkanes with carbon numbers ranging from C14 to C36.The generation of retained oil occurred through three stages.A slow growth stage of production rate was observed before reaching the peak of oil production in Stage Ⅰ.Stage Ⅱ involved a rapid increase in oil retention,with C12-C17 and C24-C32 serving as the primary components,increasing continuously during the pyrolysis process.The generation process involved the cleavage of weak bonds,including bridging bonds(hydroxyl,oxy,peroxy,imino,amino,and nitro),ether bonds,and acid amides in the first stage(Ro=0.50%-0.75%).The carbon chains in aromatic ring structures with heteroatomic functional groups breaks in the second stage(R_(o)=0.75%-1.20%).In the third stage(R_(o)=1.20%-2.50%),the ring structures underwent ring-opening reactions to synthesize iso-short-chain olefins and radicals,while further breakdown of aliphatic chains occurred.By coupling pyrolysis simu-lation experiments and molecular simulation technology,the evolution characteristics and bond breaking mechanism of retained oil in three stages were revealed,providing a reference for the for-mation and evolution mechanism of retained oil.展开更多
When performing tasks,unmanned clusters often face a variety of strategy choices.One of the key issues in unmanned cluster tasks is the method through which to design autonomous collaboration and cooperative evolution...When performing tasks,unmanned clusters often face a variety of strategy choices.One of the key issues in unmanned cluster tasks is the method through which to design autonomous collaboration and cooperative evolution mechanisms that allow for unmanned clusters to maximize their overall task effective-ness under the condition of strategic diversity.This paper ana-lyzes these task requirements from three perspectives:the diver-sity of the decision space,information network construction,and the autonomous collaboration mechanism.Then,this paper pro-poses a method for solving the problem of strategy selection diversity under two network structures.Next,this paper presents a Moran-rule-based evolution dynamics model for unmanned cluster strategies and a vision-driven-mechanism-based evolu-tion dynamics model for unmanned cluster strategy in the con-text of strategy selection diversity according to various unmanned cluster application scenarios.Finally,this paper pro-vides a simulation analysis of the effects of relevant parameters such as the payoff factor and cluster size on cooperative evolu-tion in autonomous cluster collaboration for the two types of models.On this basis,this paper presents advice for effectively addressing diverse choices in unmanned cluster tasks,thereby providing decision support for practical applications of unmanned cluster tasks.展开更多
Lake wetlands play a crucial role as global carbon sinks,significantly contributing to carbon storage and ecological balance.This study estimates the quarterly carbon storage in the Dongting Lake wetland for the years...Lake wetlands play a crucial role as global carbon sinks,significantly contributing to carbon storage and ecological balance.This study estimates the quarterly carbon storage in the Dongting Lake wetland for the years 2010,2015,and 2020,using MODIS remote sensing imagery and the InVEST model.A Structural Equation Model(SEM)was then employed to analyze the driving factors behind changes in carbon storage.Results show that intra-annual carbon storage increases and then decreases,with maximum level in the third quarter(average of 34.242 Tg)and a minimum one in the first quarter(average of 21.435 Tg).From 2010 to 2020,inter-annual carbon storage variations initially exhibited an increasing trend before decreasing,with the peak annual average carbon storage reaching 32.230 Tg in 2015.Notably,the coefficient of variation for intra-annual carbon storage increased from 8.5%in 2010 to 25.8%in 2020.Key driving factors that influence carbon storage changes include surface solar radiation,temperature,and water level,with carbon storage positively correlated with surface solar radiation and temperature,and negatively correlated with water level.These findings reveal the spatiotemporal evolution characteristics of carbon storage in the Dongting Lake wetland,offering scientific guidance for wetland conservation and regional climate adaptation policies.展开更多
The development of cost-effective,highly efficient and stable catalysts is critical to promote the industrial alkaline hydrogen evolution reaction(HER).However,single-component catalysts often cannot handle the multip...The development of cost-effective,highly efficient and stable catalysts is critical to promote the industrial alkaline hydrogen evolution reaction(HER).However,single-component catalysts often cannot handle the multiple kinetic steps during hydrogen production.To address this challenge,a heterogeneous catalyst comprising metal Co,CoO and carbon-doped Mo_(2)N(Co–CoO–C/Mo_(2)N/CC)was synthesized by heat treatment of carbon cloth-supported CoMoO_(4) microrods in a mixed reduction atmosphere.The resulting catalyst has rich interfaces,exhibiting excellent initial HER activity with an overpotential of 27 mV at 10 mA·cm^(−2) and a Tafel slope of 37 mV·dec^(−1).Further studies show that the activity and stability of the catalyst can be tailored by the dynamic surface reconfiguration and doping effects.The carbon doping and high crystallinity in Mo_(2)N help to reduce the dissolution of Mo and the surface metal Co is preferentially converted into stable Co(OH)2,thus stabilizing the structure of the catalyst and coordinating various reaction kinetics.In an electrolyzer comprising a heterogeneous Co–CoO–C/Mo_(2)N cathode and NiFe layered double hydroxides(LDH)anode,only 1.58 V is required to achieve a current density of 50 mA·cm^(−2),outperforming Pt/RuO catalysts.After continuous electrolysis for 100 h,the potential increases by merely 19 mV from the initial 1.58 V,indicating excellent stability.This study presents a novel strategy for developing highly active and stable heterogeneous catalysts,offering insights into the dynamic evolution of catalyst structures and laying the groundwork for designing efficient and stable composite catalysts for energy conversion applications.展开更多
The hot deformation behavior of GH3230 superalloy under selected deformation conditions ranging from 950 to 1150℃with strain rates ranging from 0.01 to 10 s^(–1)was studied through isothermal hot compression experim...The hot deformation behavior of GH3230 superalloy under selected deformation conditions ranging from 950 to 1150℃with strain rates ranging from 0.01 to 10 s^(–1)was studied through isothermal hot compression experiments.Based on the obtained flow stresses,a strain-compensated Arrhenius-type model was developed for the description of hot deformation behavior,and the consistency of the predicted flow stresses with the experimental values confirms the accuracy of the developed model.Furthermore,the processing maps were constructed and classified into the instability domain,low-dissipation stability domain and high-dissipation stability domain in accordance with the dynamic material model and the instability criterion.Microstructure observations indicated that the instability domain exhibits the adiabatic shear bands formation,and the low-power dissipation domain exhibits partial dynamic recrystallization(DRX),with the temperature increase/strain rate decrease being favorable for the DRX.The high-dissipation stability domain was occupied by uniformly fine equiaxed grains,and was identified as the optimal processing window,which corresponds to the deformation conditions at 1070–1150℃ with strain rates ranging from 0.01 to 0.15 s^(–1).Moreover,various DRX mechanisms are observed to occur during the hot deformation,which include the discontinuous dynamic recrystallization,characterized by nucleation at bulged boundaries,the continuous dynamic recrystallization with subgrain progressive rotation and the particle stimulated nucleation mechanism with stimulated nucleation of carbide particles.展开更多
AZ31 Mg alloy plates with bimodal grain structures were fabricated via conventional extrusion under varying temperatures and speeds to investigate the mechanisms governing dynamic recrystallization(DRX)and texture evo...AZ31 Mg alloy plates with bimodal grain structures were fabricated via conventional extrusion under varying temperatures and speeds to investigate the mechanisms governing dynamic recrystallization(DRX)and texture evolution.Although all samples exhibited similar DRXed grain sizes(5.0–6.5μm)and fractions(76%–80%),they developed distinct c-axis orientations and mechanical properties.The P1 sample(350℃,0.1 mm/min)exhibited the lowest yield strength(∼192 MPa)but the highest elongation(∼18.2%),whereas the P3 sample(400℃,0.6 mm/min)showed the highest yield strength(∼241 MPa)and the lowest elongation(∼14.2%).The P2 sample(400℃,0.1 mm/min)demonstrated intermediate behavior(∼226 MPa,∼17.7%).These variations were primarily attributed to differences in c-axis orientations,particularly their alignment with respect to the normal direction(ND)and their slight deviation from the extrusion direction(ED).Microstructural analysis revealed that distinct DRX mechanisms were activated under different extrusion conditions.P1 predominantly exhibited twinning-induced dynamic recrystallization(TDRX)and continuous dynamic recrystallization(CDRX),whereas P3 primarily showed CDRX and discontinuous dynamic recrystallization(DDRX).These DRX mechanisms,in combination with the activated slip systems governed by the evolving local stress state,collectively contributed to orientation rotation and texture development.During the early stage of extrusion,tensile strain along the ED promoted basalslip,rotating the c-axes toward the ND.As deformation progressed,compressive strain along the ND became dominant.In P1,basalslip remained active,aligning the c-axes along the ND and forming a smaller angle with the ED.In contrast,P3 exhibited predominant pyramidal<c+a>slip,resulting in a pronounced deviation of the c-axes from the ND and a slightly larger angle relative to the ED.The P2 sample exhibited a transitional texture state between those of P1 and P3.展开更多
Developing efficient and durable alkaline hydrogen evolution reaction(HER)catalysts is crucial for realizing high-performance,practical anion exchange membrane water electrolyzer(AEMWE)operating at ampere-level curren...Developing efficient and durable alkaline hydrogen evolution reaction(HER)catalysts is crucial for realizing high-performance,practical anion exchange membrane water electrolyzer(AEMWE)operating at ampere-level current densities.Although atomically dispersed Platinum(Pt)catalysts offer significant potential for enhancing atom utilization,their HER performance and durability are limited by the inflexibility in valence electron transfer between Pt and the support.In this study,we utilize asymmetrically single-atom copper(Cu)with tunable valence states as a valence electron reservoir(VER)to dynamically regulate the Pt 5d valence states,achieving efficient alkaline HER.In situ synchrotron radiation and theoretical calculations demonstrate that the dynamic evolution of the Pt 5d valence electron configuration optimizes the adsorption strengths of reaction intermediates.Meanwhile,single-atom Cu accelerates the rate-limiting water dissociation,and Pt facilitates subsequent^(*)H coupling.The catalyst requires only 23.5 and 177.2 mV overpotentials to achieve current densities of 10 and 500 mA cm^(-2)in 1 M KOH.Notably,the PtCu/NC exhibits a~57%lower hydrogen evolution barrier than Pt/NC.Moreover,the PtCu/NC-based AEMWE operates for over 600 h at an industrially relevant current density of 500 mA cm^(-2).展开更多
The doping evolution of the nodal electron dynamics in the trilayer cuprate superconductor Bi_(2)Sr_(2)Ca_(2)Cu_(3)O_(10+δ)(Bi2223)is investigated using high-resolution laser-based angle-resolved photoemission spectr...The doping evolution of the nodal electron dynamics in the trilayer cuprate superconductor Bi_(2)Sr_(2)Ca_(2)Cu_(3)O_(10+δ)(Bi2223)is investigated using high-resolution laser-based angle-resolved photoemission spectroscopy(ARPES).Bi2223single crystals with different doping levels are prepared by controlled annealing,which cover the underdoped,optimallydoped and overdoped regions.The electronic phase diagram of Bi2223 is established which describes the Tcdependence on the sample doping level.The doping dependence of the nodal Fermi momentum for the outer(OP)and inner(IP)CuO_(2)planes is determined.Charge distribution imbalance between the OP and IP CuO_(2)planes is quantified,showing enhanced disparity with increasing doping.Nodal band dispersions demonstrate a prominent kink at~94 meV in the IP band,attributed to the unique Cu coordination in the IP plane,while a weaker~60 meV kink is observed in the OP band.The nodal Fermi velocity of both OP and IP bands is nearly constant at~1.62 eV·A independent of doping.These results provide important information to understand the origin of high Tcand superconductivity mechanism in high temperature cuprate superconductors.展开更多
Based on MTS Landmark 370.50 rock dynamic and static load fatigue test system and acoustic emission(AE)monitoring method,the damage characteristics and energy evolution law of high static load coal-rock combination(CR...Based on MTS Landmark 370.50 rock dynamic and static load fatigue test system and acoustic emission(AE)monitoring method,the damage characteristics and energy evolution law of high static load coal-rock combination(CRC)under the influence of dynamic load parameters were studied.The main results are as follows:1)Dynamic load increases the rheological properties and damage fracture development of CRC.With the increase of the amplitude and frequency of the dynamic load,the number of dynamic load cycles required for the failure of the CRC decreases,the irreversible strain increases,and the failure of sample accelerates;2)The AE positioning events during the loading process of the specimen decrease with the increase of the dynamic load amplitude,and increase with the increase of the dynamic load frequency;3)The fractal dimension,total energy and cumulative elastic energy of the broken particles of the CRC increase with the increase of the amplitude and frequency of the dynamic load.The fractal dimension corresponding to the increase of the dynamic load frequency is larger,and the energy and cumulative elastic energy corresponding to the increase of the dynamic load amplitude are larger.展开更多
In this study,the hot deformation behavior and microstructural evolution of the GH 4706 alloy under various thermal processing parameters(TPPs)were investigated through hot deformation experiments and electron backsca...In this study,the hot deformation behavior and microstructural evolution of the GH 4706 alloy under various thermal processing parameters(TPPs)were investigated through hot deformation experiments and electron backscatter diffraction(EBSD)microstructural characterization.The findings suggest that increasing hot compression temperature(T)and reducing strain rate(ε)enhance the degree of dynamic recrystallization(DRX),significantly reducing flow stress and weakening texture intensity.Increasing strain(ε)promotes DRX,with the overall texture strength initially increasing before decreasing.During hot compression at 1000−1100℃,discontinuous dynamic recrystallization(DDRX),continuous dynamic recrystallization(CDRX),and twin-induced dynamic recrystallization(TDRX)jointly influence texture development.Among these,DDRX plays a dominant role,with numerous DDRX grains exhibiting dispersed orientations,significantly contributing to texture weakening.The CDRX mechanism induces a limited number of randomly oriented grains within the deformed grains,and its contribution to texture weakening is enhanced with increasingεand decreasing T.The TDRX mechanism generates DRX grains withinΣ3 twin boundaries deviating from their theoretical orientation,and these grains inherit the twin orientation,exerting a limited effect on texture weakening.These findings provide a theoretical foundation for a deeper understanding of DRX behavior and texture evolution in the GH 4706 during hot working.展开更多
The 2D/3D heterojunction perovskites have garnered increasing attention due to their exceptional moisture and thermal stability.However,few works have paid attention to the influence of the subsequent change process o...The 2D/3D heterojunction perovskites have garnered increasing attention due to their exceptional moisture and thermal stability.However,few works have paid attention to the influence of the subsequent change process of 2D/3D heterojunction PSC on the stability of PSCs.Moreover,the evolution of the interface and carrier dynamic behavior of the 2D/3D perovskite films with long-term operation has not been systematically developed befo re.In this work,the effects of 2D/3 D heterojunction evolution on the interface of perovskite films and different carrier dynamics during 2D/3D evolution are systematically analyzed for the first time.The decomposition of 2D/3D heterojunction in the perovskite film will have a certain impact on the surface and carrier dynamics behavior of perovskite.During the evolution of 2D/3D heterojunction,PbI_(2)crystals will appear,which will improve the interfacial energy level matching between the electron transport layer and perovskite film.With a long evolution time,some holes will appear on the surface of perovskite film.The open circuit voltage(V_(OC))of PSCs increased from 1.14 to1.18 V and the PCE increased to 23.21%after 300 h storage in the nitrogen atmosphere,and maintained 89%initial performance for with 3000 h stability test in N_(2)box.This discovery has a significant role in promoting the development of inverted heterojunction PSCs and constructing the revolution mechanism of charge carrier dynamic.展开更多
Coralline soils,specialized materials found extensively in the South China Sea,are playing an increasingly vital role in engineering projects.However,like most terrigenous soils,fine-grained coral soil is prone to shr...Coralline soils,specialized materials found extensively in the South China Sea,are playing an increasingly vital role in engineering projects.However,like most terrigenous soils,fine-grained coral soil is prone to shrinkage and cracking,which can significantly affect its engineering properties and ultimately jeopardize engineering safety.This paper presents a desiccation cracking test of fine-grained coral soil,with a particular focus on the thickness effect.The study involved measuring the water content and recording the evolution of desiccation cracking.Advanced image processing technology is employed to analyze the variations in crack parameters,clod parameters,fractal dimensions,frequency distributions,and desiccation cracking propagation velocities of fine-grained coral soil.Furthermore,the dynamic evolution of desiccation cracking under the influence of layer thickness is analyzed.A comprehensive crack evolution model is proposed,encompassing both top-down and bottom-up crack propagation,as well as internal tensile cracking.This work introduces novel metrics for the propagation velocity of the total crack area,the characteristic propagation velocities of desiccation cracks,and the acceleration of crack propagation.Through data fitting,theoretical formulas for soil water evaporation,propagation velocities of desiccation cracks,and crack propagation acceleration are derived,laying a foundation for future soil cracking theories.展开更多
基金The project supported by the National Science Foundation(USA)through grant MSS-9258115by the National Natural Science Foundation of China
文摘An evolving material structure is in a non-equilibrium state, with free energy expressed by the generalized coordinates. A global approach leads to robust computations for the generalized thermodynamic forces. Those forces drive various kinetic processes, causing dissipation at spots, along curves, surfaces and interfaces, and within volumetric regions. The actual evolution path, and therefore the final equilibrium state, is determined by the energetics and kinetics. A virtual work principle Links the free energy landscape and the kinetic processes, and assigns a viscous environment to every point on the landscape. The approach leads to a dynamical system that governs the evolution of generalized coordinates. The microstructural evolution is globally characterized by a basin map in the coordinate space; and by a diversity map and a variety map in the parameter space. The control of basin boundaries raises the issue of energetic and kinetic bifurcations. The variation of basin boundaries under different sets of controlling parameters provides an analytical way to plot the diversity maps of structural evolution.
基金supported by the National Natural Science Foundation of China(Grant No.41671004)
文摘There are several basins with high sediment yield in the Pisha-sandstone covering area of the east wing of the Ordos Plateau. Due to the lack of targeted research on the dynamical characteristics of geomorphic evolution that plays an important role in the sand production, this paper analyzed the tectonic activity intensity and erosion characteristics of the area. The results show that the intensity of tectonic activities in the area is generally moderateweak and shows an unconspicuous increase from north to south. Tectonic activity is manifested mainly in the form of uplift. The uplift rate in the lower reaches of each basin is greater than the erosion rate,which is prominent in the Kuyehe and the Tuweihe rivers. During the uplift of the regional topography,the most serious parts under erosion are generally concentrated in the upstream and midstream of basins. All longitudinal profiles of the basins have a shape close to an exponential function, which indicates that they are in the early stage of erosion evolution. The mechanisms of geomorphologic evolution of these basins have a great similarity. The conservative estimate of historical average erosion rate was less than 182–520 t/(km^2·yr), much less than that of the modern times. The average stream power values are typically distributed between 4 and102 W/m, with the larger being in the Kuyehe and the Tuweihe rivers and the smallest being in the Qinshuihe River. The maximum stream power value appears in the downstream reach, which should be the main reason for the particles being directly injected into the Yellow River. From the perspective of geomorphological evolution, the current soil and water conservation measures can hardly cure the erosion of these basins in the long run.
基金the support of the National Key R&D Program of China (2017YFC1501102)the National Natural Science Foundation of China (51639007)the Youth Science and Technology Fund of Sichuan Province (2016JQ0011)
文摘A pair of flumes with variable inclinations were employed to investigate the entrainment mechanics and dynamical evolution of a debris avalanche/flow. A fixed quantity of solid and water mixture was released from a constant elevation and accelerated along a higher chute to impact substrate materials with different water contents and particle size distributions in the lower chute. Two high-speed cameras, pore and earth pressure detecting devices, were placed in the substrate materials where severe scouring occurs in order to collect multiple measurements of dynamical and mechanical parameters. The entrainment dynamics were verified by geometrical analysis and quasi-static simulation. The results show that wet and fine materials that are placed in the lower chute with steeper slopes are easily entrained during debris flow initiation, the pattern of which can be described by Coulomb friction and the Mohr-Coulomb law. Elaborate measurements of dynamical parameters enable the results of an elementary computational framework to predict the time-dependent scouring depth ht, which provides insight into rapidly determining debris flow propagation. Finally, the post-entrainment dynamics were studied. The results indicate that the propagation and the amplification of debris flows along erodible beds are dominated by the velocity and the solid volume fraction of the mixed substrate, and the coarse particle group of the substrate is a key feature affected by momentum changes.
基金supported by the National Natural Science Foundation of China (Grant Nos 10674174,10604009 and 10725521)the National Fundamental Research Programme of China (Grant No 2006CB921400 and 2007CB814800)Natural Science Foundation of Liaoning Province of China (Grant No 20072054)
文摘This paper investigates the dynamical instability and adiabatic evolution of the atom homonuclear-trimer dark state of a condensate system in a stimulated Raman adiabatic passage aided by Feshbach resonance. It obtains analytically the regions for the appearance of dynamical instability caused by the interparticle interactions. Moreover, the adiabatic property of the dark state is also studied in terms of a newly defined adiabatic fidelity. It shows that the nonlinear collisions have a negative effect on the adiabaticity of the dark state and hence reduce the conversion efficiency.
基金Supported by the Foundation of Scientific Research Education and Innovations under Grant No.11609506,Jinan University
文摘We have set up a new reduced model Hamiltonian for the polariton system, in which the nonlinear interaction contains the rotating term k l （ a ＋ b ＋ ab＋） and the attractive two-mode squeezed coupling - k2 （ a ＋ b＋ ＋ ab ） . The dynamical evolution of this system has been solved and the nonclassical features relevant to the second-order and high-order squeezing have been obtained in an analytical form. For the first time, in contrast to the existing result, we have confirmed for the phonon field that the attractive two-mode squeezed interaction will not only result in the second-order and high-order squeezing in X-component with the time evolution, but also in time average. Furthermore, the phenomena of collapse and revival of inversion will occur as well in the time evolution of the average number of photon and phonon, as also in the second-order and high-order squeezing of photon field, particularly, in the high-order squeezing of phonon field.
基金supported by the Russian Foundation for Basic Research (grant 18-32-00283 mol_a)(A. Perminov)Ministry of Science and Higher Education of the Russian Federation under the grant 075-15-2020-780 (No.13.1902.21.0039)(E. Kuznetsov)。
文摘This article is devoted to studying the dynamical evolution and orbital stability of compact extrasolar threeplanetary system GJ 3138. In this system, all semimajor axes are less than 0.7 au. The modeling of planetary motion is performed using the averaged semi-analytical motion theory of the second order in planetary masses,which the authors construct. Unknown and known with errors orbital elements vary in allowable limits to obtain a set of initial conditions. Each of these initial conditions is applied for the modeling of planetary motion. The assumption about the stability of observed planetary systems allows to eliminate the initial conditions leading to excessive growth of the orbital eccentricities and inclinations and to identify those under which these orbital elements conserve moderate values over the whole modeling interval. Thus, it becomes possible to limit the range of possible values of unknown orbital elements and determine their most probable values in terms of stability.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11104171,11404199,11574187 and 11604188the Youth Science Foundation of Shanxi Province of China under Grant No 2012021003-1the Natural Science Foundation for Youths of Shanxi Province under Grant Nos 201601D201027 and 1331KSC
文摘We investigate the dynamics of parity-and time-reversal（PT） symmetric two-energy-level atoms in the presence of two optical and one radio-frequency fields. The strength and relative phase of fields can drive the system from the unbroken to the broken PT symmetric regions. Compared with the Hermitian model, Rabi-type oscillation is still observed, and the oscillation characteristics are also adjusted by the strength and relative phase in the region of the unbroken symmetry. At the exception point, the oscillation breaks down. To better understand the underlying properties we study the effective Bloch dynamics and find that the emergence of the PT components of the fixed points is the feature of the PT symmetry breaking and the projections in the x–y plane can be controlled with high flexibility compared with the standard two-level system with the PT symmetry. It helps to study the dynamic behavior of the complex PT symmetric model.
基金the BAGUI talent program(No.2019AC26001)the National Natural Science Foundation of China(Nos.U23A2080,22371173,22171075).
文摘The remarkable power of chemistry over description and trans-formation of matters has been significantly enhanced through the development of dynamic chemistry and condensed matter chemistry[1].This progress has further elevated chemistry to a creative science and a thriving industry.The development of dynamic chemistry,span-ning from supramolecular chemistry to constitutional dynamic chem-istry,has witnessed significant advancements towards adaptive chemistry,which is characterized primarily by its self-adaption to external stimuli.This is particularly achieved in two-or three-dimensional dynamic frameworks.Meanwhile,the multi-phase evolution resulting from the emerging of solid-to-liquid transition plat-form is assuming an increasingly crucial role in condensed matter chemistry[2].
基金financially supported by the National Natural Science Foundation of China (Grant No. 42072150)
文摘To accurately investigate the evolution characteristics and generation mechanism of retained oil,the study analyzed organic-rich lacustrine shale samples from the Paleogene Kongdian Formation in Cangdong Sag,Bohai Bay Basin.This analysis involves Rock-Eval pyrolysis,pyrolysis simulation experiments,Gas Chromatograph Mass Spectrometer(GC-MS),and reactive molecular dynamics simulations(ReaxFF).The results revealed the retained oil primarily consisted of n-alkanes with carbon numbers ranging from C14 to C36.The generation of retained oil occurred through three stages.A slow growth stage of production rate was observed before reaching the peak of oil production in Stage Ⅰ.Stage Ⅱ involved a rapid increase in oil retention,with C12-C17 and C24-C32 serving as the primary components,increasing continuously during the pyrolysis process.The generation process involved the cleavage of weak bonds,including bridging bonds(hydroxyl,oxy,peroxy,imino,amino,and nitro),ether bonds,and acid amides in the first stage(Ro=0.50%-0.75%).The carbon chains in aromatic ring structures with heteroatomic functional groups breaks in the second stage(R_(o)=0.75%-1.20%).In the third stage(R_(o)=1.20%-2.50%),the ring structures underwent ring-opening reactions to synthesize iso-short-chain olefins and radicals,while further breakdown of aliphatic chains occurred.By coupling pyrolysis simu-lation experiments and molecular simulation technology,the evolution characteristics and bond breaking mechanism of retained oil in three stages were revealed,providing a reference for the for-mation and evolution mechanism of retained oil.
基金supported by the National Natural Science Foundation of China(72471240).
文摘When performing tasks,unmanned clusters often face a variety of strategy choices.One of the key issues in unmanned cluster tasks is the method through which to design autonomous collaboration and cooperative evolution mechanisms that allow for unmanned clusters to maximize their overall task effective-ness under the condition of strategic diversity.This paper ana-lyzes these task requirements from three perspectives:the diver-sity of the decision space,information network construction,and the autonomous collaboration mechanism.Then,this paper pro-poses a method for solving the problem of strategy selection diversity under two network structures.Next,this paper presents a Moran-rule-based evolution dynamics model for unmanned cluster strategies and a vision-driven-mechanism-based evolu-tion dynamics model for unmanned cluster strategy in the con-text of strategy selection diversity according to various unmanned cluster application scenarios.Finally,this paper pro-vides a simulation analysis of the effects of relevant parameters such as the payoff factor and cluster size on cooperative evolu-tion in autonomous cluster collaboration for the two types of models.On this basis,this paper presents advice for effectively addressing diverse choices in unmanned cluster tasks,thereby providing decision support for practical applications of unmanned cluster tasks.
基金supported by National Natural Science Foundation of China(No.42272291,No.42077176)the Strategic Research Program of the National Natural Science Foundation of China(No.42242202).
文摘Lake wetlands play a crucial role as global carbon sinks,significantly contributing to carbon storage and ecological balance.This study estimates the quarterly carbon storage in the Dongting Lake wetland for the years 2010,2015,and 2020,using MODIS remote sensing imagery and the InVEST model.A Structural Equation Model(SEM)was then employed to analyze the driving factors behind changes in carbon storage.Results show that intra-annual carbon storage increases and then decreases,with maximum level in the third quarter(average of 34.242 Tg)and a minimum one in the first quarter(average of 21.435 Tg).From 2010 to 2020,inter-annual carbon storage variations initially exhibited an increasing trend before decreasing,with the peak annual average carbon storage reaching 32.230 Tg in 2015.Notably,the coefficient of variation for intra-annual carbon storage increased from 8.5%in 2010 to 25.8%in 2020.Key driving factors that influence carbon storage changes include surface solar radiation,temperature,and water level,with carbon storage positively correlated with surface solar radiation and temperature,and negatively correlated with water level.These findings reveal the spatiotemporal evolution characteristics of carbon storage in the Dongting Lake wetland,offering scientific guidance for wetland conservation and regional climate adaptation policies.
基金supported by the National Natural Science Foundation of China(Nos.22379116,U2003130 and U2004210)the Outstanding Youth Foundation of Natural Science Foundation of Hubei Province(No.2020CFA099)+1 种基金the Foundation of Science Research Program from Hubei Provincial Department of Education(No.Q20221101)the Innovation group of Key Research and Development Program of Hubei Province(Nos.2021BAA208 and 2022BCA061).
文摘The development of cost-effective,highly efficient and stable catalysts is critical to promote the industrial alkaline hydrogen evolution reaction(HER).However,single-component catalysts often cannot handle the multiple kinetic steps during hydrogen production.To address this challenge,a heterogeneous catalyst comprising metal Co,CoO and carbon-doped Mo_(2)N(Co–CoO–C/Mo_(2)N/CC)was synthesized by heat treatment of carbon cloth-supported CoMoO_(4) microrods in a mixed reduction atmosphere.The resulting catalyst has rich interfaces,exhibiting excellent initial HER activity with an overpotential of 27 mV at 10 mA·cm^(−2) and a Tafel slope of 37 mV·dec^(−1).Further studies show that the activity and stability of the catalyst can be tailored by the dynamic surface reconfiguration and doping effects.The carbon doping and high crystallinity in Mo_(2)N help to reduce the dissolution of Mo and the surface metal Co is preferentially converted into stable Co(OH)2,thus stabilizing the structure of the catalyst and coordinating various reaction kinetics.In an electrolyzer comprising a heterogeneous Co–CoO–C/Mo_(2)N cathode and NiFe layered double hydroxides(LDH)anode,only 1.58 V is required to achieve a current density of 50 mA·cm^(−2),outperforming Pt/RuO catalysts.After continuous electrolysis for 100 h,the potential increases by merely 19 mV from the initial 1.58 V,indicating excellent stability.This study presents a novel strategy for developing highly active and stable heterogeneous catalysts,offering insights into the dynamic evolution of catalyst structures and laying the groundwork for designing efficient and stable composite catalysts for energy conversion applications.
基金the National Key Research and Development Program of China(No.2016YFB0700505)the National Natural Science Foundation of China(No.51571020).
文摘The hot deformation behavior of GH3230 superalloy under selected deformation conditions ranging from 950 to 1150℃with strain rates ranging from 0.01 to 10 s^(–1)was studied through isothermal hot compression experiments.Based on the obtained flow stresses,a strain-compensated Arrhenius-type model was developed for the description of hot deformation behavior,and the consistency of the predicted flow stresses with the experimental values confirms the accuracy of the developed model.Furthermore,the processing maps were constructed and classified into the instability domain,low-dissipation stability domain and high-dissipation stability domain in accordance with the dynamic material model and the instability criterion.Microstructure observations indicated that the instability domain exhibits the adiabatic shear bands formation,and the low-power dissipation domain exhibits partial dynamic recrystallization(DRX),with the temperature increase/strain rate decrease being favorable for the DRX.The high-dissipation stability domain was occupied by uniformly fine equiaxed grains,and was identified as the optimal processing window,which corresponds to the deformation conditions at 1070–1150℃ with strain rates ranging from 0.01 to 0.15 s^(–1).Moreover,various DRX mechanisms are observed to occur during the hot deformation,which include the discontinuous dynamic recrystallization,characterized by nucleation at bulged boundaries,the continuous dynamic recrystallization with subgrain progressive rotation and the particle stimulated nucleation mechanism with stimulated nucleation of carbide particles.
基金supported by National Key Research&Development Program of China(Grant no.2022YFE0110600)National Natural Science Foundation(Grant no.52220105003)+3 种基金the State Key Laboratory of Advanced Welding and Joining,Harbin Institute of Technology(Grant no.XNDCQQ2910201124)the National Natural Science Foundation for Young Scientists of China(Grant nos.51801042 and 51704088)Natural Science Foundation of Heilongjiang Province-Outstanding Youth Fund(Grant no.YQ2020E006)JSPS KAKENHI(Grant no.JP21H01669).
文摘AZ31 Mg alloy plates with bimodal grain structures were fabricated via conventional extrusion under varying temperatures and speeds to investigate the mechanisms governing dynamic recrystallization(DRX)and texture evolution.Although all samples exhibited similar DRXed grain sizes(5.0–6.5μm)and fractions(76%–80%),they developed distinct c-axis orientations and mechanical properties.The P1 sample(350℃,0.1 mm/min)exhibited the lowest yield strength(∼192 MPa)but the highest elongation(∼18.2%),whereas the P3 sample(400℃,0.6 mm/min)showed the highest yield strength(∼241 MPa)and the lowest elongation(∼14.2%).The P2 sample(400℃,0.1 mm/min)demonstrated intermediate behavior(∼226 MPa,∼17.7%).These variations were primarily attributed to differences in c-axis orientations,particularly their alignment with respect to the normal direction(ND)and their slight deviation from the extrusion direction(ED).Microstructural analysis revealed that distinct DRX mechanisms were activated under different extrusion conditions.P1 predominantly exhibited twinning-induced dynamic recrystallization(TDRX)and continuous dynamic recrystallization(CDRX),whereas P3 primarily showed CDRX and discontinuous dynamic recrystallization(DDRX).These DRX mechanisms,in combination with the activated slip systems governed by the evolving local stress state,collectively contributed to orientation rotation and texture development.During the early stage of extrusion,tensile strain along the ED promoted basalslip,rotating the c-axes toward the ND.As deformation progressed,compressive strain along the ND became dominant.In P1,basalslip remained active,aligning the c-axes along the ND and forming a smaller angle with the ED.In contrast,P3 exhibited predominant pyramidal<c+a>slip,resulting in a pronounced deviation of the c-axes from the ND and a slightly larger angle relative to the ED.The P2 sample exhibited a transitional texture state between those of P1 and P3.
基金supported by the Ningbo Top-Talent Team Program,Program for the National Natural Science Foundation of China(22106166)the Yongjiang Innovative Individual Introduction of China,and the China Postdoctoral Science Foundation(2022M723253)。
文摘Developing efficient and durable alkaline hydrogen evolution reaction(HER)catalysts is crucial for realizing high-performance,practical anion exchange membrane water electrolyzer(AEMWE)operating at ampere-level current densities.Although atomically dispersed Platinum(Pt)catalysts offer significant potential for enhancing atom utilization,their HER performance and durability are limited by the inflexibility in valence electron transfer between Pt and the support.In this study,we utilize asymmetrically single-atom copper(Cu)with tunable valence states as a valence electron reservoir(VER)to dynamically regulate the Pt 5d valence states,achieving efficient alkaline HER.In situ synchrotron radiation and theoretical calculations demonstrate that the dynamic evolution of the Pt 5d valence electron configuration optimizes the adsorption strengths of reaction intermediates.Meanwhile,single-atom Cu accelerates the rate-limiting water dissociation,and Pt facilitates subsequent^(*)H coupling.The catalyst requires only 23.5 and 177.2 mV overpotentials to achieve current densities of 10 and 500 mA cm^(-2)in 1 M KOH.Notably,the PtCu/NC exhibits a~57%lower hydrogen evolution barrier than Pt/NC.Moreover,the PtCu/NC-based AEMWE operates for over 600 h at an industrially relevant current density of 500 mA cm^(-2).
基金supported by the National Natural Science Foundation of China(Grant Nos.12488201 by X.J.Z.,12374066 by L.Z.,and 12374154 by X.T.L.)the National Key Research and Development Program of China(Grant Nos.2021YFA1401800 by X.J.Z.,2022YFA1604200 by L.Z.,2022YFA1403900 by G.D.L.and 2023YFA1406000by X.T.L.)+3 种基金the Strategic Priority Research Program(B)of the Chinese Academy of Sciences(Grant No.XDB25000000by X.J.Z.)Innovation Program for Quantum Science and Technology(Grant No.2021ZD0301800 by X.J.Z.)the Youth Innovation Promotion Association of CAS(Grant No.Y2021006 by L.Z.)the Synergetic Extreme Condition User Facility(SECUF)。
文摘The doping evolution of the nodal electron dynamics in the trilayer cuprate superconductor Bi_(2)Sr_(2)Ca_(2)Cu_(3)O_(10+δ)(Bi2223)is investigated using high-resolution laser-based angle-resolved photoemission spectroscopy(ARPES).Bi2223single crystals with different doping levels are prepared by controlled annealing,which cover the underdoped,optimallydoped and overdoped regions.The electronic phase diagram of Bi2223 is established which describes the Tcdependence on the sample doping level.The doping dependence of the nodal Fermi momentum for the outer(OP)and inner(IP)CuO_(2)planes is determined.Charge distribution imbalance between the OP and IP CuO_(2)planes is quantified,showing enhanced disparity with increasing doping.Nodal band dispersions demonstrate a prominent kink at~94 meV in the IP band,attributed to the unique Cu coordination in the IP plane,while a weaker~60 meV kink is observed in the OP band.The nodal Fermi velocity of both OP and IP bands is nearly constant at~1.62 eV·A independent of doping.These results provide important information to understand the origin of high Tcand superconductivity mechanism in high temperature cuprate superconductors.
基金Project(51874281)supported by the National Natural Science Foundation of ChinaProject(2024M752698)supported by China Postdoctoral Science FoundationProject(2025WLKXJ041)supported by the Graduate Innovation Program of China University of Mining and Technology。
文摘Based on MTS Landmark 370.50 rock dynamic and static load fatigue test system and acoustic emission(AE)monitoring method,the damage characteristics and energy evolution law of high static load coal-rock combination(CRC)under the influence of dynamic load parameters were studied.The main results are as follows:1)Dynamic load increases the rheological properties and damage fracture development of CRC.With the increase of the amplitude and frequency of the dynamic load,the number of dynamic load cycles required for the failure of the CRC decreases,the irreversible strain increases,and the failure of sample accelerates;2)The AE positioning events during the loading process of the specimen decrease with the increase of the dynamic load amplitude,and increase with the increase of the dynamic load frequency;3)The fractal dimension,total energy and cumulative elastic energy of the broken particles of the CRC increase with the increase of the amplitude and frequency of the dynamic load.The fractal dimension corresponding to the increase of the dynamic load frequency is larger,and the energy and cumulative elastic energy corresponding to the increase of the dynamic load amplitude are larger.
基金Project(2022YFB3705103)supported by the National Key R&D Program,China。
文摘In this study,the hot deformation behavior and microstructural evolution of the GH 4706 alloy under various thermal processing parameters(TPPs)were investigated through hot deformation experiments and electron backscatter diffraction(EBSD)microstructural characterization.The findings suggest that increasing hot compression temperature(T)and reducing strain rate(ε)enhance the degree of dynamic recrystallization(DRX),significantly reducing flow stress and weakening texture intensity.Increasing strain(ε)promotes DRX,with the overall texture strength initially increasing before decreasing.During hot compression at 1000−1100℃,discontinuous dynamic recrystallization(DDRX),continuous dynamic recrystallization(CDRX),and twin-induced dynamic recrystallization(TDRX)jointly influence texture development.Among these,DDRX plays a dominant role,with numerous DDRX grains exhibiting dispersed orientations,significantly contributing to texture weakening.The CDRX mechanism induces a limited number of randomly oriented grains within the deformed grains,and its contribution to texture weakening is enhanced with increasingεand decreasing T.The TDRX mechanism generates DRX grains withinΣ3 twin boundaries deviating from their theoretical orientation,and these grains inherit the twin orientation,exerting a limited effect on texture weakening.These findings provide a theoretical foundation for a deeper understanding of DRX behavior and texture evolution in the GH 4706 during hot working.
基金financial support provided by the Sichuan Science and Technology Program(No.2022NSFSC0226)Sichuan Science and Technology Program(No.2023ZYD0163)+6 种基金the Production-Education Integration Demonstration Project of Sichuan Provincethe Photovoltaic Industry Production-Education Integration Comprehensive Demonstration Base of Sichuan Province(Sichuan Financial Education[2022]No.106)China Tianfu Yongxing Laboratory Science and Technology Key Project(2023KJGG15)National Key Research and Development Program of China(2022YFB3803300)Beijing Natural Science Foundation(IS23037)the Department for Energy Security and Net Zero(project ID:NEXTCCUS)the ACT program(Accelerating CCS Technologies,Horizon2020 project NO.691712)。
文摘The 2D/3D heterojunction perovskites have garnered increasing attention due to their exceptional moisture and thermal stability.However,few works have paid attention to the influence of the subsequent change process of 2D/3D heterojunction PSC on the stability of PSCs.Moreover,the evolution of the interface and carrier dynamic behavior of the 2D/3D perovskite films with long-term operation has not been systematically developed befo re.In this work,the effects of 2D/3 D heterojunction evolution on the interface of perovskite films and different carrier dynamics during 2D/3D evolution are systematically analyzed for the first time.The decomposition of 2D/3D heterojunction in the perovskite film will have a certain impact on the surface and carrier dynamics behavior of perovskite.During the evolution of 2D/3D heterojunction,PbI_(2)crystals will appear,which will improve the interfacial energy level matching between the electron transport layer and perovskite film.With a long evolution time,some holes will appear on the surface of perovskite film.The open circuit voltage(V_(OC))of PSCs increased from 1.14 to1.18 V and the PCE increased to 23.21%after 300 h storage in the nitrogen atmosphere,and maintained 89%initial performance for with 3000 h stability test in N_(2)box.This discovery has a significant role in promoting the development of inverted heterojunction PSCs and constructing the revolution mechanism of charge carrier dynamic.
基金supported by the Fundamental Research Funds for the Central Universities(Grant No.2022CDJQY-012)the Innovation Group Science Foundation of the Natural Science Foundation of Chongqing,China(Grant No.cstc2020jcyj-cxttX0003).
文摘Coralline soils,specialized materials found extensively in the South China Sea,are playing an increasingly vital role in engineering projects.However,like most terrigenous soils,fine-grained coral soil is prone to shrinkage and cracking,which can significantly affect its engineering properties and ultimately jeopardize engineering safety.This paper presents a desiccation cracking test of fine-grained coral soil,with a particular focus on the thickness effect.The study involved measuring the water content and recording the evolution of desiccation cracking.Advanced image processing technology is employed to analyze the variations in crack parameters,clod parameters,fractal dimensions,frequency distributions,and desiccation cracking propagation velocities of fine-grained coral soil.Furthermore,the dynamic evolution of desiccation cracking under the influence of layer thickness is analyzed.A comprehensive crack evolution model is proposed,encompassing both top-down and bottom-up crack propagation,as well as internal tensile cracking.This work introduces novel metrics for the propagation velocity of the total crack area,the characteristic propagation velocities of desiccation cracks,and the acceleration of crack propagation.Through data fitting,theoretical formulas for soil water evaporation,propagation velocities of desiccation cracks,and crack propagation acceleration are derived,laying a foundation for future soil cracking theories.
