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
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
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
Earthquakes may inflict varied levels of damage on mountains.Understanding the deformation properties of earthquake-damaged rock masses is critical for evaluating rocky slope stability over time.Taking the phyllite of...Earthquakes may inflict varied levels of damage on mountains.Understanding the deformation properties of earthquake-damaged rock masses is critical for evaluating rocky slope stability over time.Taking the phyllite of the Xinmo Village rockslide as the research object,the degradation features of the phyllite are investigated through laboratory tests,and a discrete-element numerical approach that fully accounts for the progressive rock deterioration is presented.The approach is then used to investigate the evolution characteristics of phyllite under various dynamic and static loading circumstances.Results show that the remaining strength of rock decreases with increasing dynamic cyclic loading(DCL)amplitude and times but increases with increasing frequency.As the dynamic damage degree increases,rock failure modes become more complex,and microcracks expand in a more preferential orientation,as well as a denser spatial distribution.Dynamic damage cracks act as the dominant paths for the macroscopic failure surface of the rock.The results indicate that the input energy and dissipated energy increase with fluctuating and linear trends with the advance of the DCL,respectively.The peak strain energy and acoustic emission(AE)magnitude decrease with increasing dynamic damage degrees,and the distribution of AE events displays temporal dispersion and spatial clustering characteristics,which is attributed to a decrease in the rock's potential for storing energy.展开更多
Designing high-efficiency photocatalysts by the construction of organic/inorganic heterojunctions is considered to be an effective approach for improving photocatalytic hydrogen evolution reaction(HER)activity.This wo...Designing high-efficiency photocatalysts by the construction of organic/inorganic heterojunctions is considered to be an effective approach for improving photocatalytic hydrogen evolution reaction(HER)activity.This work designed and built unique S-scheme heterojunctions by in-situ growing inorganic WO_(3) nanoparticles with excellent oxidation ability on fused-sulfone-modified covalent organic frameworks(FS-COF)with strong reduction ability.It is found that FS-COF and WO_(3) have a well-matched staggered band alignment.The best-designed FS-COF/WO_(3)-20%exhibits a maximum photocatalytic HER rate of 24.7 mmol g^(-1) h^(-1) under visible light irradiation,which is 1.4 times greater than the pure FS-COF.Moreover,photogenerated electron-hole pairs can be separated and utilized more efficiently thanks to the FS-COF/WO_(3) heterojunction's ability to create a favorable internal electric field resulting from the difference in work functions between FS-COF and WO_(3),which speeds up the transfer dynamics of photoinduced electrons from WO_(3) to FS-COF through an additional interfacial electron-transfer channel obeying the directional S-scheme migration mechanism.Furthermore,the S-scheme migration mechanism of photoinduced charge carriers instead of the type-II mechanism was confirmed by the signal intensity of•O_(2)−species from spin-trapping electron paramagnetic resonance spectra over the single component and the formed heterojunction.It ensures the photoexcited electrons maintain on the lowest unoccupied molecular orbital of FS-COF with a strong reduction ability to participate in photocatalytic HER,resulting in a significantly boosted H_(2) evolution rate.Based on organic/inorganic coupling,this work offers a strategy for creating particular S-scheme heterojunction photocatalysts.展开更多
Lithium-ion batteries are at the forefront of modern energy storage technology.However,the accumulation of by-products such as ethylene and carbon dioxide during charging and discharging cycles reduces battery effecti...Lithium-ion batteries are at the forefront of modern energy storage technology.However,the accumulation of by-products such as ethylene and carbon dioxide during charging and discharging cycles reduces battery effective capacity and threatens large-scale safe performance.With significant advantages over ethylene carbonate(EC)electrolytes,fluorinated electrolytes can more effectively suppress internal gas evolution,thereby improving battery safety and cycling stability.To reveal the mechanism behind gas formation in lithium-ion batteries,our study investigated the transport behavior and interfacial products of fluorinated electrolytes under various operation conditions,including electrode material and electrolyte composition.Innovatively,we applied the reaction network integrator ReacNetGenerator to the analysis of the solid electrolyte interface(SEI)in lithium batteries,providing more molecular fingerprint information from the perspective of specific products.Using reactive molecular dynamics(MD)simulations with the ReaxFF force field and EChemDID,complemented by density functional theory(DFT)calculations,our results demonstrate that fluorinated electrolytes can effectively suppress the decomposition of LiPF_(6) to produce toxic gases PFs and PF_3.DFT analysis further reveals that highly fluorinated solvents(e.g.,FEMC)enhance the anti-reduction stability of PF_(6)~-through synergistic regulation of molecular orbital energy levels,thermodynamic electron affinity,charge transfer,and electrostatic potential distribution,thereby mitigating LiPF_(6) decomposition.Additionally,fluorinated electrolytes generate significantly more LiF components than non-fluorinated ones to promote the formation of a stable and durable solid electrolyte interface(SEI).Experimental validations via XPS and GC-MS confirm reduced CO_(2) generation and LiF-enriched SEI formation,aligning with simulation and DFT data.The findings provide valuable insights for the design of advanced electrolytes aimed at ensuring large-scale,safe energy storage solutions.展开更多
The flow stress behavior and microstructure development of Al-5Zn-2Mg （7005） aluminum alloy were studied by hot compression tests at deformation temperatures between 300-500 ＆#176;C and strain rates between 0.05-50...The flow stress behavior and microstructure development of Al-5Zn-2Mg （7005） aluminum alloy were studied by hot compression tests at deformation temperatures between 300-500 ＆#176;C and strain rates between 0.05-50 s-1. The deformed structures of the samples were observed by optical microscopy （OM）, transmission electron microscopy （TEM） and electron backscattering diffraction （EBSD） analysis. The calculated activation energy is 147 kJ/mol, which is very close to the activation energy for lattice self-diffusion in aluminum （142 kJ/mol）. Dynamic recovery is the dominant restoration mechanism during the deformation. At high strain rate of 50 s-1, temperature rise due to deformation heating leads to a significant flow softening. Microstructure observations indicated that the remaining softening after deformation heating correction at high strain rate and the softening observed at high temperature are associated with grain coarsening induced by grain boundary migration during dynamic recovery process.展开更多
Quantitative assessment of microscale slip activities and plastic localizations is essential for understanding the complex deformation mechanisms in crystalline materials.However,few experimental studies have been abl...Quantitative assessment of microscale slip activities and plastic localizations is essential for understanding the complex deformation mechanisms in crystalline materials.However,few experimental studies have been able to dynamically measure the deformation fields of rapidly evolving slip activities at the microscale.In this study,we used the Sampling Moire?Method(SMM)to directly measure the dynamic deformation fields of slip activities in Nickel-Based Single-Crystal(NBSC)superalloy under in-situ tensile test,and the strain and displacement fields under the evolving microplastic events with intense slip activities around the notch of the NBSC superalloy specimen were obtained for the first time.The dynamic evolution of slip bands was quantitatively characterized through detailed statistical analysis of strains and displacements under different loads.The locations of the initial appearance of slip traces were successfully predicted by the regions of plasticity localization.The results show that the deformation fields exhibit both high spatial and temporal resolutions,enabling the capture of nanometer-scale displacement fields and visualization of the dynamic fluidity of slip accumulation.This method demonstrates the superiority of the dynamic characterization of the plastic deformation field at the microscale and the promise of its application for characterizing the slip activities of various crystalline metals.展开更多
As an efficient method of solving subgame-perfect Nash equilibrium,the backward induction is analyzed from an evolutionary point of view in this paper,replacing a player with a population and turning a game into a pop...As an efficient method of solving subgame-perfect Nash equilibrium,the backward induction is analyzed from an evolutionary point of view in this paper,replacing a player with a population and turning a game into a population game,which shows that equilibrium of a perfect information game is the unique evolutionarily stable outcome for dynamic models in the limit.展开更多
This paper provides a detailed analysis of the factors influencing the evolution of rural settlements, including natural environmental constraints, infrastructure, regional cultural inheritance and integration, urbani...This paper provides a detailed analysis of the factors influencing the evolution of rural settlements, including natural environmental constraints, infrastructure, regional cultural inheritance and integration, urbanization and rural industrial transformation, land use refor- mation and innovation, rural household behavior conversion, macro-control policy factors, and so on. Based on differences between the ways and degree of effect on rural settlement evolution, these factors are classified into basic factors, new-type factors and mutation factors The drive of basic factors mainly focuses on the traditional inheritance of rural settlements, the new-type factors mainly affect rural settlement transition, and the mutation factors may bring about sudden changes. All these factors constitute a ＂three-wheel＂ driving mechanism for the evolution of rural settlements, and shape three typical driver paths： slow smooth path under the basic factors, new path to rapid development under the new-type factors, and the sudden change path under the mutation factors. The paper also investigates the overall situation of rural settlement evolution in the aspects of settlement system, settlement scale, settlement morphology, settlement function, settlement culture, settlement environment, etc. The general process of rural settlement evolution is divided into four stages： initial, transi- tional, developmental, and mature stages.展开更多
Dynamic recrystallization of 304N stainless steel was investigated at deformation temperatures of 900- 1 300 ℃ and strain rates of 0.01 10 s by a Gleeble-1500 thermo-mechanical simulator. And the microstructure evol...Dynamic recrystallization of 304N stainless steel was investigated at deformation temperatures of 900- 1 300 ℃ and strain rates of 0.01 10 s by a Gleeble-1500 thermo-mechanical simulator. And the microstructure evolu lions of specimens with different deformation temperatures were observed by using a transmission electron micro scope. Results indicated that compared with conventional AISI 304 austenitie stainless steel, 304N stainless steel has higher deformation resistance force and deformation activation energy under similar conditions. In addition, the flow stress constitutive equation of 304N stainless steel was obtained by regression analysis of experimental stress strain data, and the calculated values proposed by the mathematical model agree well with the experimental results.展开更多
Researching the dynamic distribution characteristics and trend evolution of agricultural carbon emissions is of considerable significance in formulating an effective agricultural carbon reduction policy.Based on measu...Researching the dynamic distribution characteristics and trend evolution of agricultural carbon emissions is of considerable significance in formulating an effective agricultural carbon reduction policy.Based on measurement of agricultural carbon emissions of 31 provinces over the period 2002-2011,the study observed regional differences and the dynamic evolution of distribution of agricultural carbon emissions using agricultural carbon intensity as the indicator,accompanied by Gini coefficients and the kernel density estimation method.The results demonstrate first that agricultural carbon emissions for China show an obvious nonequilibrium nature in regard to spatial distribution.According to the differences in agricultural carbon emissions dynamic trends,we divided the 31 regions into four types- continuous decline,fluctuating decline,continuous increase,and fluctuating increase.Further,agricultural carbon emissions intensity showed a downward trend with significant differences in the research areas.Second,the gap in spatial distribution of national agricultural carbon emissions is gradually expanding based on the results calculated by Gini coefficient.From the perception of regional differences in agricultural carbon emissions,the eastern region showed an average level,the gap was more obvious in the central region,while western region showed a trend of fluctuating downward.Third,according to estimation by kernel density,the regional disparity in agricultural carbon emissions had a downward,but limited,trend.In regard to agricultural carbon emissions over the three areas,the regional gap not only tended to decrease but also showed a "four way" differentiation phenomenon in the eastern region.The difference in the central region difference was narrower.On the whole,the gap for the western region reduced steadily over a small range.展开更多
Quantitative studies on the evolution and dynamics of the deepwater area of Pearl River Mouth basin （PRMB） were carried out based on the latest geological and seismic data. The study area is generally in an extensio...Quantitative studies on the evolution and dynamics of the deepwater area of Pearl River Mouth basin （PRMB） were carried out based on the latest geological and seismic data. The study area is generally in an extensional state during the Cenozoic. The major extension happened in the earlier syn-rift stages before 23 Ma and the extension after 23 Ma is negligible. Two rapid subsidence periods, 32-23 Ma and 5.3-2.6 Ma, are identified, which are related to the abrupt heat decay during margin breakup and the collision between the Philippine Sea plate and the Eurasian plate, respectively. The strongest crustal thinning in the Baiyun （白云） sag may trigger the syn-rift volcanism along the weak faulted belt around the sag. The Cenozoic tectonic evolution of the study area could be divided into five stages： rifting （～50-40 Ma）, rift-drift transition （～40-32 Ma）, early post-breakup （～32-23 Ma）, thermal subsidence （～23-5.3 Ma） and neotectonic movement （～5.3-0 Ma）.展开更多
The continuous growth of air traffic has led to acute airspace congestion and severe delays, which threatens operation safety and cause enormous economic loss. Flight assignment is an economical and effective strategi...The continuous growth of air traffic has led to acute airspace congestion and severe delays, which threatens operation safety and cause enormous economic loss. Flight assignment is an economical and effective strategic plan to reduce the flight delay and airspace congestion by rea- sonably regulating the air traffic flow of China. However, it is a large-scale combinatorial optimiza- tion problem which is difficult to solve. In order to improve the quality of solutions, an effective multi-objective parallel evolution algorithm （MPEA） framework with dynamic migration interval strategy is presented in this work. Firstly, multiple evolution populations are constructed to solve the problem simultaneously to enhance the optimization capability. Then a new strategy is pro- posed to dynamically change the migration interval among different evolution populations to improve the efficiency of the cooperation of populations. Finally, the cooperative co-evolution （CC） algorithm combined with non-dominated sorting genetic algorithm II （NSGA-II） is intro- duced for each population. Empirical studies using the real air traffic data of the Chinese air route network and daily flight plans show that our method outperforms the existing approaches, multi- objective genetic algorithm （MOGA）, multi-objective evolutionary algorithm based on decom- position （MOEA/D）, CC-based multi-objective algorithm （CCMA） as well as other two MPEAs with different migration interval strategies.展开更多
Before the emergence of modern modes of transport, the traditional road infra structure was the major historical means of carrying out nationwide socioeconomic exchange However, the history of transport infrastructure...Before the emergence of modern modes of transport, the traditional road infra structure was the major historical means of carrying out nationwide socioeconomic exchange However, the history of transport infrastructure has received little attention from researchers. Given this background, the work reported here examined the longterm development of transport networks in China. The national road network was selected for study and the 3500 years from 1600 BC to 1900 AD was chosen as the study period. Indicators were designed for the maturity level of road networks and an accessibility model was developed for the paths of the shortest distance. The evolution of the road network in China since the Shang Dynasty （1600 BC） was described and its major features were summarized to reveal longterm regu larities. The maturity level of the road network and its accessibility was assessed and regions with good and poor networks were identified. The relationship between China＇s natural, social and economic systems and the road network were discussed. Our analysis shows that the road network in China has a number of longterm regularities. The continuously expanding road network follows a path of inland expansion especially towards the border areas. How ever, its coverage and accessibility are characterized by a coreperipheral configuration, which has close relationships with, not only the natural conditions, but also national defense and warfare. The centralization of national power, national land governance, postal transport, the transport of specialized cargos, and international trade are also related to the develop ment of the road network. This research draws attention to the evolving regularities of trans port networks.展开更多
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.
基金the financial support from the National Natural Science Foundation of China(Grant No.U22A20603)the National Key Research and Development Program of China(Grant No.2023YFC3008300).
文摘Earthquakes may inflict varied levels of damage on mountains.Understanding the deformation properties of earthquake-damaged rock masses is critical for evaluating rocky slope stability over time.Taking the phyllite of the Xinmo Village rockslide as the research object,the degradation features of the phyllite are investigated through laboratory tests,and a discrete-element numerical approach that fully accounts for the progressive rock deterioration is presented.The approach is then used to investigate the evolution characteristics of phyllite under various dynamic and static loading circumstances.Results show that the remaining strength of rock decreases with increasing dynamic cyclic loading(DCL)amplitude and times but increases with increasing frequency.As the dynamic damage degree increases,rock failure modes become more complex,and microcracks expand in a more preferential orientation,as well as a denser spatial distribution.Dynamic damage cracks act as the dominant paths for the macroscopic failure surface of the rock.The results indicate that the input energy and dissipated energy increase with fluctuating and linear trends with the advance of the DCL,respectively.The peak strain energy and acoustic emission(AE)magnitude decrease with increasing dynamic damage degrees,and the distribution of AE events displays temporal dispersion and spatial clustering characteristics,which is attributed to a decrease in the rock's potential for storing energy.
文摘Designing high-efficiency photocatalysts by the construction of organic/inorganic heterojunctions is considered to be an effective approach for improving photocatalytic hydrogen evolution reaction(HER)activity.This work designed and built unique S-scheme heterojunctions by in-situ growing inorganic WO_(3) nanoparticles with excellent oxidation ability on fused-sulfone-modified covalent organic frameworks(FS-COF)with strong reduction ability.It is found that FS-COF and WO_(3) have a well-matched staggered band alignment.The best-designed FS-COF/WO_(3)-20%exhibits a maximum photocatalytic HER rate of 24.7 mmol g^(-1) h^(-1) under visible light irradiation,which is 1.4 times greater than the pure FS-COF.Moreover,photogenerated electron-hole pairs can be separated and utilized more efficiently thanks to the FS-COF/WO_(3) heterojunction's ability to create a favorable internal electric field resulting from the difference in work functions between FS-COF and WO_(3),which speeds up the transfer dynamics of photoinduced electrons from WO_(3) to FS-COF through an additional interfacial electron-transfer channel obeying the directional S-scheme migration mechanism.Furthermore,the S-scheme migration mechanism of photoinduced charge carriers instead of the type-II mechanism was confirmed by the signal intensity of•O_(2)−species from spin-trapping electron paramagnetic resonance spectra over the single component and the formed heterojunction.It ensures the photoexcited electrons maintain on the lowest unoccupied molecular orbital of FS-COF with a strong reduction ability to participate in photocatalytic HER,resulting in a significantly boosted H_(2) evolution rate.Based on organic/inorganic coupling,this work offers a strategy for creating particular S-scheme heterojunction photocatalysts.
基金funding support from the National Natural Science Foundation of China(Grant No.52302302)the National Key R&D Program of China(Grant No.2022YFE0208000)+1 种基金the Fundamental Research Funds for the Central Universitiesthe Special Funds of Tongji University for“Sino-German Cooperation 2.0 Strategy”。
文摘Lithium-ion batteries are at the forefront of modern energy storage technology.However,the accumulation of by-products such as ethylene and carbon dioxide during charging and discharging cycles reduces battery effective capacity and threatens large-scale safe performance.With significant advantages over ethylene carbonate(EC)electrolytes,fluorinated electrolytes can more effectively suppress internal gas evolution,thereby improving battery safety and cycling stability.To reveal the mechanism behind gas formation in lithium-ion batteries,our study investigated the transport behavior and interfacial products of fluorinated electrolytes under various operation conditions,including electrode material and electrolyte composition.Innovatively,we applied the reaction network integrator ReacNetGenerator to the analysis of the solid electrolyte interface(SEI)in lithium batteries,providing more molecular fingerprint information from the perspective of specific products.Using reactive molecular dynamics(MD)simulations with the ReaxFF force field and EChemDID,complemented by density functional theory(DFT)calculations,our results demonstrate that fluorinated electrolytes can effectively suppress the decomposition of LiPF_(6) to produce toxic gases PFs and PF_3.DFT analysis further reveals that highly fluorinated solvents(e.g.,FEMC)enhance the anti-reduction stability of PF_(6)~-through synergistic regulation of molecular orbital energy levels,thermodynamic electron affinity,charge transfer,and electrostatic potential distribution,thereby mitigating LiPF_(6) decomposition.Additionally,fluorinated electrolytes generate significantly more LiF components than non-fluorinated ones to promote the formation of a stable and durable solid electrolyte interface(SEI).Experimental validations via XPS and GC-MS confirm reduced CO_(2) generation and LiF-enriched SEI formation,aligning with simulation and DFT data.The findings provide valuable insights for the design of advanced electrolytes aimed at ensuring large-scale,safe energy storage solutions.
基金Project(51075132)supported by the National Natural Science Foundation of ChinaProject(20090161110027)supported by the Doctoral Fund of Ministry of Education of ChinaProject(2011BAG03B02)supported by National Key Technology R&D Program during the 12th Five-Year Plan Period,China
文摘The flow stress behavior and microstructure development of Al-5Zn-2Mg （7005） aluminum alloy were studied by hot compression tests at deformation temperatures between 300-500 ＆#176;C and strain rates between 0.05-50 s-1. The deformed structures of the samples were observed by optical microscopy （OM）, transmission electron microscopy （TEM） and electron backscattering diffraction （EBSD） analysis. The calculated activation energy is 147 kJ/mol, which is very close to the activation energy for lattice self-diffusion in aluminum （142 kJ/mol）. Dynamic recovery is the dominant restoration mechanism during the deformation. At high strain rate of 50 s-1, temperature rise due to deformation heating leads to a significant flow softening. Microstructure observations indicated that the remaining softening after deformation heating correction at high strain rate and the softening observed at high temperature are associated with grain coarsening induced by grain boundary migration during dynamic recovery process.
基金supported by the Natural Science Foundation of China(No.12372176)the National Science and Technology Major Project of China(No.J2019-IV-0007-0075)。
文摘Quantitative assessment of microscale slip activities and plastic localizations is essential for understanding the complex deformation mechanisms in crystalline materials.However,few experimental studies have been able to dynamically measure the deformation fields of rapidly evolving slip activities at the microscale.In this study,we used the Sampling Moire?Method(SMM)to directly measure the dynamic deformation fields of slip activities in Nickel-Based Single-Crystal(NBSC)superalloy under in-situ tensile test,and the strain and displacement fields under the evolving microplastic events with intense slip activities around the notch of the NBSC superalloy specimen were obtained for the first time.The dynamic evolution of slip bands was quantitatively characterized through detailed statistical analysis of strains and displacements under different loads.The locations of the initial appearance of slip traces were successfully predicted by the regions of plasticity localization.The results show that the deformation fields exhibit both high spatial and temporal resolutions,enabling the capture of nanometer-scale displacement fields and visualization of the dynamic fluidity of slip accumulation.This method demonstrates the superiority of the dynamic characterization of the plastic deformation field at the microscale and the promise of its application for characterizing the slip activities of various crystalline metals.
文摘As an efficient method of solving subgame-perfect Nash equilibrium,the backward induction is analyzed from an evolutionary point of view in this paper,replacing a player with a population and turning a game into a population game,which shows that equilibrium of a perfect information game is the unique evolutionarily stable outcome for dynamic models in the limit.
基金National Social Science Foundation of China, No.07BJL033 Youth Foundation of Hunan Normal University, No.Z080625 Key Subject of Hunan Normal University about Human Geography
文摘This paper provides a detailed analysis of the factors influencing the evolution of rural settlements, including natural environmental constraints, infrastructure, regional cultural inheritance and integration, urbanization and rural industrial transformation, land use refor- mation and innovation, rural household behavior conversion, macro-control policy factors, and so on. Based on differences between the ways and degree of effect on rural settlement evolution, these factors are classified into basic factors, new-type factors and mutation factors The drive of basic factors mainly focuses on the traditional inheritance of rural settlements, the new-type factors mainly affect rural settlement transition, and the mutation factors may bring about sudden changes. All these factors constitute a ＂three-wheel＂ driving mechanism for the evolution of rural settlements, and shape three typical driver paths： slow smooth path under the basic factors, new path to rapid development under the new-type factors, and the sudden change path under the mutation factors. The paper also investigates the overall situation of rural settlement evolution in the aspects of settlement system, settlement scale, settlement morphology, settlement function, settlement culture, settlement environment, etc. The general process of rural settlement evolution is divided into four stages： initial, transi- tional, developmental, and mature stages.
基金Item Sponsored by High-Tech Research and Development Program(863 Program)of China(2006AA03Z525)
文摘Dynamic recrystallization of 304N stainless steel was investigated at deformation temperatures of 900- 1 300 ℃ and strain rates of 0.01 10 s by a Gleeble-1500 thermo-mechanical simulator. And the microstructure evolu lions of specimens with different deformation temperatures were observed by using a transmission electron micro scope. Results indicated that compared with conventional AISI 304 austenitie stainless steel, 304N stainless steel has higher deformation resistance force and deformation activation energy under similar conditions. In addition, the flow stress constitutive equation of 304N stainless steel was obtained by regression analysis of experimental stress strain data, and the calculated values proposed by the mathematical model agree well with the experimental results.
基金funded by the National Natural Science Foundation of China[grant number 71273105]the Fundamental Research Funds for the Central Universities[grant number 2013YB12]
文摘Researching the dynamic distribution characteristics and trend evolution of agricultural carbon emissions is of considerable significance in formulating an effective agricultural carbon reduction policy.Based on measurement of agricultural carbon emissions of 31 provinces over the period 2002-2011,the study observed regional differences and the dynamic evolution of distribution of agricultural carbon emissions using agricultural carbon intensity as the indicator,accompanied by Gini coefficients and the kernel density estimation method.The results demonstrate first that agricultural carbon emissions for China show an obvious nonequilibrium nature in regard to spatial distribution.According to the differences in agricultural carbon emissions dynamic trends,we divided the 31 regions into four types- continuous decline,fluctuating decline,continuous increase,and fluctuating increase.Further,agricultural carbon emissions intensity showed a downward trend with significant differences in the research areas.Second,the gap in spatial distribution of national agricultural carbon emissions is gradually expanding based on the results calculated by Gini coefficient.From the perception of regional differences in agricultural carbon emissions,the eastern region showed an average level,the gap was more obvious in the central region,while western region showed a trend of fluctuating downward.Third,according to estimation by kernel density,the regional disparity in agricultural carbon emissions had a downward,but limited,trend.In regard to agricultural carbon emissions over the three areas,the regional gap not only tended to decrease but also showed a "four way" differentiation phenomenon in the eastern region.The difference in the central region difference was narrower.On the whole,the gap for the western region reduced steadily over a small range.
基金supported jointly by the CAS Knowledge In-novation Program (No. KZCX2-YW-203)the National Basic Research Program of China (No. 2007CB411703)+2 种基金Key Labo-ratory of Marginal Sea Geology, Chinese Academy of Sciences (No. MSGL08-22)the MLR National Petroleum Resource Strategic Target Survey and Evaluation Programthe Tai-shan Scholarship Program of Shandong Province
文摘Quantitative studies on the evolution and dynamics of the deepwater area of Pearl River Mouth basin （PRMB） were carried out based on the latest geological and seismic data. The study area is generally in an extensional state during the Cenozoic. The major extension happened in the earlier syn-rift stages before 23 Ma and the extension after 23 Ma is negligible. Two rapid subsidence periods, 32-23 Ma and 5.3-2.6 Ma, are identified, which are related to the abrupt heat decay during margin breakup and the collision between the Philippine Sea plate and the Eurasian plate, respectively. The strongest crustal thinning in the Baiyun （白云） sag may trigger the syn-rift volcanism along the weak faulted belt around the sag. The Cenozoic tectonic evolution of the study area could be divided into five stages： rifting （～50-40 Ma）, rift-drift transition （～40-32 Ma）, early post-breakup （～32-23 Ma）, thermal subsidence （～23-5.3 Ma） and neotectonic movement （～5.3-0 Ma）.
基金co-supported by the Foundation for Innovative Research Groups of the National Natural Science Foundation of China (No. 60921001)
文摘The continuous growth of air traffic has led to acute airspace congestion and severe delays, which threatens operation safety and cause enormous economic loss. Flight assignment is an economical and effective strategic plan to reduce the flight delay and airspace congestion by rea- sonably regulating the air traffic flow of China. However, it is a large-scale combinatorial optimiza- tion problem which is difficult to solve. In order to improve the quality of solutions, an effective multi-objective parallel evolution algorithm （MPEA） framework with dynamic migration interval strategy is presented in this work. Firstly, multiple evolution populations are constructed to solve the problem simultaneously to enhance the optimization capability. Then a new strategy is pro- posed to dynamically change the migration interval among different evolution populations to improve the efficiency of the cooperation of populations. Finally, the cooperative co-evolution （CC） algorithm combined with non-dominated sorting genetic algorithm II （NSGA-II） is intro- duced for each population. Empirical studies using the real air traffic data of the Chinese air route network and daily flight plans show that our method outperforms the existing approaches, multi- objective genetic algorithm （MOGA）, multi-objective evolutionary algorithm based on decom- position （MOEA/D）, CC-based multi-objective algorithm （CCMA） as well as other two MPEAs with different migration interval strategies.
基金Key Research Program of the Chinese Academy of Sciences, No.KZZD-EW-06-02 Exploratory Forefront Project for the Strategic Science Plan in IGSNRR, CAS, No.2012QY004 National Natural Science Foundation of China, No.41171108
文摘Before the emergence of modern modes of transport, the traditional road infra structure was the major historical means of carrying out nationwide socioeconomic exchange However, the history of transport infrastructure has received little attention from researchers. Given this background, the work reported here examined the longterm development of transport networks in China. The national road network was selected for study and the 3500 years from 1600 BC to 1900 AD was chosen as the study period. Indicators were designed for the maturity level of road networks and an accessibility model was developed for the paths of the shortest distance. The evolution of the road network in China since the Shang Dynasty （1600 BC） was described and its major features were summarized to reveal longterm regu larities. The maturity level of the road network and its accessibility was assessed and regions with good and poor networks were identified. The relationship between China＇s natural, social and economic systems and the road network were discussed. Our analysis shows that the road network in China has a number of longterm regularities. The continuously expanding road network follows a path of inland expansion especially towards the border areas. How ever, its coverage and accessibility are characterized by a coreperipheral configuration, which has close relationships with, not only the natural conditions, but also national defense and warfare. The centralization of national power, national land governance, postal transport, the transport of specialized cargos, and international trade are also related to the develop ment of the road network. This research draws attention to the evolving regularities of trans port networks.
