In this paper,we establish some strong laws of large numbers,which are for nonindependent random variables under the framework of sublinear expectations.One of our main results is for blockwise m-dependent random vari...In this paper,we establish some strong laws of large numbers,which are for nonindependent random variables under the framework of sublinear expectations.One of our main results is for blockwise m-dependent random variables,and another is for sub-orthogonal random variables.Both extend the strong law of large numbers for independent random variables under sublinear expectations to the non-independent case.展开更多
Aqueous zinc-ion batteries(AZIBs) are regarded as one of the most promising energy conversion and storage devices.Nevertheless,side reactions and dendrite growth on the zinc metal anode hinder their widespread applica...Aqueous zinc-ion batteries(AZIBs) are regarded as one of the most promising energy conversion and storage devices.Nevertheless,side reactions and dendrite growth on the zinc metal anode hinder their widespread application.In this study,hemin was employed as a multi-functional artificial interface for the first time to inhibit the disordered growth of zinc dendrites and mitigate side reactions.Theoretical calculations indicate that hemin is preferentially adsorbed onto the zinc anode,thus blocking the interaction between the active zinc anode and electrolyte.Compared with zinc foil,the Hemin@Zn anode demonstrates enhanced corrosion resistance,a decrease in hydrogen evolution,and more orderly deposition of zinc.As expected,the symmetric cell with Hemin@Zn anode can sustain up to 4000 h at 0.2 mA/cm^(2),0.2 mAh/cm^(2).Asymmetric Zn//Cu cells exhibit an average coulombic efficiency exceeding 99.72 % during 500 cycles.Moreover,the full cell Hemin@Zn//NH_(4)V_(4)O_(10) delivers a superior capacity up to 367 m Ah/g and the discharge capacity retention reaches 124 mAh/g after 1200 cycles even at a current density of 5 A/g.This work provides a simple and effective method for constructing a robust artificial interface to promote the application of long-life AZIBs.展开更多
This paper is concerned with an initial boundary value problem for the planar magnetohydrodynamic compressible flow with temperature dependent heat conductivity in a half-line.In particular,the transverse magnetic fie...This paper is concerned with an initial boundary value problem for the planar magnetohydrodynamic compressible flow with temperature dependent heat conductivity in a half-line.In particular,the transverse magnetic field is assumed to satisfy the Neumann boundary condition,which was first investigated by Kazhikhov in 1987.We establish the global existence of the unique strong solutions to the MHD equations without any smallness conditions on the initial data.More precisely,our result can be regarded as a natural generalization of Kazhikov’s result for applying the constant heat-conductivity in bounded domains to the degenerate case in unbounded domains.展开更多
The damage evolution of polycrystalline Al with helium(He)bubbles under strongly decaying shock waves is studied by molecular dynamics simulations.A new damage region is observed near the loading side of the sample,an...The damage evolution of polycrystalline Al with helium(He)bubbles under strongly decaying shock waves is studied by molecular dynamics simulations.A new damage region is observed near the loading side of the sample,and the evolution characteristics and underlying mechanisms are elucidated.The development of damage in the new damage region begins after complete unloading of the incident shock wave and is further enhanced when the tensile stress arrives later.The damage evolution is completely controlled by the expansion-merging of He bubbles,without nucleation–growth of voids.This new damage region can be divided into two sections,each of which exhibits a unique dominant mechanism.The damage in the section closer to the loading side is due to the reverse velocity gradient formed after complete unloading of the incident shock wave,depending on the rate of decrease and the amplitude of the initial peak pressure.A high initial peak pressure that can lead to melting of material near the loading side is a necessary condition for the formation of the new damage region,since a significant reverse velocity gradient can only be established if melting occurs.The dominant mechanism in the section distant from the loading side is the action of tensile stress,associated with the profile of the incident shock wave upon reaching the free surface,which determines the material phase near the free surface.Moreover,the presence of He bubbles is another critical factor for formation of the new damage region,which does not occur in pure Al samples.展开更多
Lithium-ion batteries(LIBs)face significant limitations in low-temperature environments,with the slow interfacial de-solvation process and the hindered Li+transport through the interphase layer emerging as key obstacl...Lithium-ion batteries(LIBs)face significant limitations in low-temperature environments,with the slow interfacial de-solvation process and the hindered Li+transport through the interphase layer emerging as key obstacles beyond the issue of ionic conductivity.This investigation unveils a novel formulation that constructs an anion-rich solvation sheath within strong solvents,effectively addressing all three of these challenges to bolster low-temperature performance.The developed electrolyte,characterized by an enhanced concentration of contact ion pairs(CIPs)and aggregates(AGGs),facilitates the formation of an inorganic-rich interphase layer on the anode and cathode particles.This promotes de-solvation at low temperatures and stabilizes the electrode-electrolyte interphase.Full cells composed of LiNi_(0.6)Co_(0.2)Mn_(0.2)O_(2)(NCM622)and graphite,when equipped with this electrolyte,showcase remarkable cycle stability and capacity retention,with 93.3% retention after 500 cycles at room temperature(RT)and 95.5%after 120 cycles at -20℃.This study validates the utility of the anion-rich solvation sheath in strong solvents as a strategy for the development of low-temperature electrolytes.展开更多
This paper addresses the verification of strong currentstate opacity with respect to real-time observations generated from a discrete-event system that is modeled with time labeled Petri nets. The standard current-sta...This paper addresses the verification of strong currentstate opacity with respect to real-time observations generated from a discrete-event system that is modeled with time labeled Petri nets. The standard current-state opacity cannot completely characterize higher-level security. To ensure the higher-level security requirements of a time-dependent system, we propose a strong version of opacity known as strong current-state opacity. For any path(state-event sequence with time information)π derived from a real-time observation that ends at a secret state, the strong current-state opacity of the real-time observation signifies that there is a non-secret path with the same real-time observation as π. We propose general and non-secret state class graphs, which characterize the general and non-secret states of time-dependent systems, respectively. To capture the observable behavior of non-secret states, a non-secret observer is proposed.Finally, we develop a structure called a real-time concurrent verifier to verify the strong current-state opacity of time labeled Petri nets. This approach is efficient since the real-time concurrent verifier can be constructed by solving a certain number of linear programming problems.展开更多
The seismic data of the Laoshan Uplift in the South Yellow Sea Basin reveal a low signal-tonoise ratio and low refl ection signal energy in the deep Mesozoic–Paleozoic strata.The main reason is that the Mesozoic-Pale...The seismic data of the Laoshan Uplift in the South Yellow Sea Basin reveal a low signal-tonoise ratio and low refl ection signal energy in the deep Mesozoic–Paleozoic strata.The main reason is that the Mesozoic-Paleozoic marine carbonate rock strata are directly covered by the Cenozoic terrestrial clastic rock strata,which form a strong shielding layer.To obtain the reflection signals of the strata below the strong shielding layer,a one-way wave equation bidirectional illumination analysis of the main observation system parameters was conducted by analyzing the mechanism of the strong shielding layer.Low-frequency seismic sources are assumed to have a high illumination intensity on the reflection layer below the strong shielding layer.Accordingly,optimized acquisition parameter suggestions were proposed,and reacquisition was performed at the existing survey line locations in the Laoshan Uplift area.The imaging of the newly acquired data in the middle and deep layers was drastically improved.It revealed the unconformity between the Sinian and Cambrian under the strong shielding layer.The study yielded new insights into the tectonic and sedimentary evolution of the Lower Paleozoic in the South Yellow Sea.展开更多
Strong surface impact will produce strong vibration,which will pose a threat to the safety of nearby buried pipelines and other important lifeline projects.Based on the verified numerical method,a comprehensive numeri...Strong surface impact will produce strong vibration,which will pose a threat to the safety of nearby buried pipelines and other important lifeline projects.Based on the verified numerical method,a comprehensive numerical parameter analysis is conducted on the key influencing factors of the vibration isolation hole(VIH),which include hole diameter,hole net spacing,hole depth,hole number,hole arrangement,and soil parameters.The results indicate that a smaller ratio of net spacing to hole diameter,the deeper the hole,the multi-row hole,the hole adoption of staggered arrangements,and better site soil conditions can enhance the efficiency of the VIH barrier.The average maximum vibration reduction efficiency within the vibration isolation area can reach 42.2%.The vibration safety of adjacent oil pipelines during a dynamic compaction projection was evaluated according to existing standards,and the measurement of the VIH was recommended to reduce excessive vibration.The single-row vibration isolation scheme and three-row staggered arrangement with the same hole parameters are suggested according to different cases.The research findings can serve as a reference for the vibration safety analysis,assessment,and control of adjacent underground facilities under the influence of strong surface impact loads.展开更多
This note is to investigate the properties of strongly semipotent rings.It is proved that every strongly semipotent ring is a idempotent unit regular ring,i.e.,there exist a non-zero idempotent e and a unit u such tha...This note is to investigate the properties of strongly semipotent rings.It is proved that every strongly semipotent ring is a idempotent unit regular ring,i.e.,there exist a non-zero idempotent e and a unit u such that er=eu for all r∉J(R),where J(R)is the Jacobson radical of ring R.展开更多
In 2024,the world witnessed further transformation and instability,marked by protracted and intensified geopolitical conflicts,repeated attempts to decouple and sever supply chains,and the rapid rise of the Global Sou...In 2024,the world witnessed further transformation and instability,marked by protracted and intensified geopolitical conflicts,repeated attempts to decouple and sever supply chains,and the rapid rise of the Global South.It has become all the more clear where the once-in-a-century transformations are heading.In 2024,China acted on the blueprint drawn up at the Third Plenary Session of the 20th Central Committee of the Communist Party of China(CPC),and made big strides in deepening reform comprehensively.Marking the 75th anniversary of the founding of New China,China carried forward its great cause of national development and pressed ahead with Chinese modernization with vigor and determination.展开更多
Correction to:Nano-Micro Lett.(2025)17:24 https://doi.org/10.1007/s40820-024-01515-0 Following publication of the original article[1],the authors reported the author list needed to be updated because the last three au...Correction to:Nano-Micro Lett.(2025)17:24 https://doi.org/10.1007/s40820-024-01515-0 Following publication of the original article[1],the authors reported the author list needed to be updated because the last three author names were duplicated.The correct author list has been provided in this Correction.The original article[1]has been corrected.展开更多
HE Tangs,a family of three from Hebei Province in north China,were full of gasps of admiration as they went on a Hengqin-Macao bay cruise in southern China.The cruise started from Hengqin,a small island with remarkabl...HE Tangs,a family of three from Hebei Province in north China,were full of gasps of admiration as they went on a Hengqin-Macao bay cruise in southern China.The cruise started from Hengqin,a small island with remarkable economic achievements on the Chinese mainland,and then went past the picturesque Macao Special Administrative Region.The passengers frantically clicked away at the passing landmarks-the 338-meter Macao Tower,one of Macao’s most iconic architectures,the four spectacular sea-crossing bridges connecting Macao Peninsula and Macao’s Taipa Island,and of course the Hong Kong-Zhu-hai-Macao Bridge,the longest bridge-cum-tunnel sea crossing in the world linking Hong Kong with the city of Zhuhai on the mainland.展开更多
This article has been compiled and edited by China Report ASEAN based on an interview with the FAO Office of Youth and Women.As the Food and Agriculture Organization of the United Nations(FAO)celebrates its 80th anniv...This article has been compiled and edited by China Report ASEAN based on an interview with the FAO Office of Youth and Women.As the Food and Agriculture Organization of the United Nations(FAO)celebrates its 80th anniversary,the spotlight is shifting from solely honouring its longstanding mission to also highlighting the dynamic participation of youth and women in driving positive changes in agrifood systems.展开更多
This letter reports an all-optical measurement of laser electric field based on strong field ionization.By measuring the attosecond transient absorption spectra of krypton ions subjected to strong laser fields,we obta...This letter reports an all-optical measurement of laser electric field based on strong field ionization.By measuring the attosecond transient absorption spectra of krypton ions subjected to strong laser fields,we obtain the time-dependent effective valence-hole population,from which the driving laser waveform is retrieved with particle swarm optimization and genetic algorithm under strong-field approximation.展开更多
The present investigation introduces a composite frequency selective Rasorber(CFSR)that demonstrates a wide−1 dB transmission band,two high absorption bands with absorptivity higher than 90%,and large oblique incidenc...The present investigation introduces a composite frequency selective Rasorber(CFSR)that demonstrates a wide−1 dB transmission band,two high absorption bands with absorptivity higher than 90%,and large oblique incidence angles up to 60°.The CFSR consists of four functional layers separated by three dielectric slabs,which includes lossless metasurface-Ⅰ(MS-Ⅰ),loss metasurface-Ⅱ(MS-Ⅱ),loss metasurface-Ⅲ(MS-Ⅲ),and a three-dimensional metastructure(3D-MS).MS-Ⅰfunctions as a reflector for two absorption bands with a minimal insertion loss transmission window.MS-Ⅱis designed for high-frequency absorption.MS-Ⅲserves as a low-frequency absorption layer for CFSR and an impedance matching layer for MS-Ⅱ.The design methodologies for the transmission window in MS-III and the introduction of 3D-MS are key to achieving high-performance CFSR.The physical mechanisms of CFSR are explained through equivalent circuit model(ECM)analysis and impedance characterization.Finally,measurement results confirm that the proposed CFSR exhibits a−1 dB transmission band ranging from 8.79 to 10.41 GHz with a minimum insertion loss of 0.44 dB at 9.59 GHz;furthermore,the frequency range where reflection coefficient remains below−10 dB is measured to be between 3.33 and 18.00 GHz,aligning well with simulation outcomes.展开更多
We consider the Cauchy problem for the three-dimensional pressureless Navier-Stokes/Navier-Stokes system,which consists of the pressureless Navier-Stokes equations for(n,w)coupled with the isentropic compressible Navi...We consider the Cauchy problem for the three-dimensional pressureless Navier-Stokes/Navier-Stokes system,which consists of the pressureless Navier-Stokes equations for(n,w)coupled with the isentropic compressible Navier-Stokes equations for(ρ,u)through a drag force term n(w−u).We prove the global existence of strong solutions to the coupled system when the initial data are small perturbations of the constant equilibrium state.However,due to the pressureless structure,one can only deal with the density n of the pressureless flow through the transport equation and it is crucial to obtain the exact time-decay rates for the corresponding velocity w of the pressureless flow.To this end,we make use of the spectral analysis,low-high frequency decomposition and time-weighted energy method to deduce the large time behavior of(w,ρ,u)and consequently establish the Lyapunov stability of the density n in Sobolev space.展开更多
Strong polyelectrolyte brushes(SPBs)play an important role in enabling material surface functionalization due to their unique stimuli-responsive properties.Although the unexpected pH responsiveness of SPBs has been re...Strong polyelectrolyte brushes(SPBs)play an important role in enabling material surface functionalization due to their unique stimuli-responsive properties.Although the unexpected pH responsiveness of SPBs has been revealed in the past ten years,it is still unclear if the pH-responsive properties of SPBs are affected by the brush thickness.In this study,we employed the positively charged poly[2-(methacryloyloxy)ethyl]trimethylammonium chloride(PMETAC)and negatively charged sodium poly(styrenesulfonate)(NaPSS)brushes as model systems to explore the effect of thickness on the pH-responsive properties of SPBs.The results demonstrate that the pH-responsive properties of SPBs manifest different dependences on the brush thickness.Specifically,for both PMETAC and NaPSS brushes,the pH-responsive hydration and stiffness are influenced by the thickness,and the pH-responsive wettability and adhesion are almost unaffected by the thickness.This work not only provides a clear understanding of the relationship between the brush thickness and the pH responsiveness of SPBs,but also offers a new method to control the pH-responsive properties of SPBs.展开更多
Interface issues have consistently impeded efforts to balance a trade-off between the conductivity functionality and mechanical properties of Cu-matrix composites.Combining first-principles simulations,this study addr...Interface issues have consistently impeded efforts to balance a trade-off between the conductivity functionality and mechanical properties of Cu-matrix composites.Combining first-principles simulations,this study addresses this challenge by preparing a new Cumatrix composite reinforced with MXene,Cu/Ag@MXene composite block(CuAM-CB),which improves the compatibility between metallic Cu and nonmetallic MXene facilitated by Ag modification anchored in situ onto MXene nanosheets,thus realizing element-coupled reinforcement of Ag at the Cu/MXene heterointerfaces.Benefiting from the strong interaction between Ag and C atoms from in situ self-reduction,as well as the excellent compatibility between Ag and Cu atoms(both IB group metals),Ag atoms act as a mediator for the electron transport and mechanical connection at the Cu/MXene heterointerfaces,enabling CuAM-CB to achieve integrated high conductivity functionality(up to 95%IACS)and strong mechanical properties(with a strength-plasticity product of∼18 GPa%).展开更多
Solid strong base catalysts have high potentials in a variety of reactions due to the advantages of negligible corrosion,easy separation,and high efficiency.However,two issues hinder the applications of such catalysts...Solid strong base catalysts have high potentials in a variety of reactions due to the advantages of negligible corrosion,easy separation,and high efficiency.However,two issues hinder the applications of such catalysts seriously,namely aggregation of basic sites and leaching of active species during reactions.The development of solid strong base catalysts with active sites that are highly dispersed and stable remains a pronounced challenge.In this work,we employed a two-step reduction strategy to anchor Na single atoms on nitrogen-doped porous carbon(NPC)support,producing a high-performance solid strongly basic catalyst named as Na1/NPC.The alkali precursor NaNO3was converted to Na_(2)O on NPC at 400℃,in which conventional solid base catalyst Na_(2)O/NPC was generated.Upon heat treatment at 850oC,Na_(2)O was further reduced to Na single atoms anchored on NPC,creating Na1/NPC.Experimental studies and theoretical calculations show that Na is structurally embedded on the support in penta-coordinated configuration(Na-C_(3)N_(2)).The synergistic effect of highly dispersed Na atoms and nitrogen doping results in uncommon catalytic activity and stability.In transesterification between methanol and ethylene carbonate to produce dimethyl carbonate(DMC),the yield of DMC reaches 48.4%over Na1/NPC,corresponding to a turnover frequency(TOF)of 129.4 h^(-1),which is far beyond the conventional counterpart Na_(2)O/NPC(63.3 h^(-1))and various reported solid base catalysts.The catalytic activity of Na1/NPC almost keeps constant during five cycles,while 87%of activity is lost for Na_(2)O/NPC due to the leaching of basic sites.This work might offer new ideas for the development of efficient single-atom solid strong base catalysts with high efficiency.展开更多
文摘In this paper,we establish some strong laws of large numbers,which are for nonindependent random variables under the framework of sublinear expectations.One of our main results is for blockwise m-dependent random variables,and another is for sub-orthogonal random variables.Both extend the strong law of large numbers for independent random variables under sublinear expectations to the non-independent case.
基金financially supported by the National Natural Science Foundation of China (No.52372188)Natural Science Foundation of Henan (Nos.242300421625,252300421333)+4 种基金CAS Henan Industrial Technology Innovation & Incubation Center (No.2024121)Key Scientific Research Project of Education Department of Henan Province (Nos.22A150042,23A150038,and 24A150019)2023 Introduction of studying abroad talent programthe China Postdoctoral Science Foundation (No.2019 M652546)Key Project of Science and Technology of Henan Province (No.252102240007)。
文摘Aqueous zinc-ion batteries(AZIBs) are regarded as one of the most promising energy conversion and storage devices.Nevertheless,side reactions and dendrite growth on the zinc metal anode hinder their widespread application.In this study,hemin was employed as a multi-functional artificial interface for the first time to inhibit the disordered growth of zinc dendrites and mitigate side reactions.Theoretical calculations indicate that hemin is preferentially adsorbed onto the zinc anode,thus blocking the interaction between the active zinc anode and electrolyte.Compared with zinc foil,the Hemin@Zn anode demonstrates enhanced corrosion resistance,a decrease in hydrogen evolution,and more orderly deposition of zinc.As expected,the symmetric cell with Hemin@Zn anode can sustain up to 4000 h at 0.2 mA/cm^(2),0.2 mAh/cm^(2).Asymmetric Zn//Cu cells exhibit an average coulombic efficiency exceeding 99.72 % during 500 cycles.Moreover,the full cell Hemin@Zn//NH_(4)V_(4)O_(10) delivers a superior capacity up to 367 m Ah/g and the discharge capacity retention reaches 124 mAh/g after 1200 cycles even at a current density of 5 A/g.This work provides a simple and effective method for constructing a robust artificial interface to promote the application of long-life AZIBs.
基金supported by the National Natural Science Foundation of China(12401279,12371219)the Double-Thousand Plan of Jiangxi Province(jxsq2023201115)the Academic and Technical Leaders Training Plan of Jiangxi Province(20212BCJ23027).
文摘This paper is concerned with an initial boundary value problem for the planar magnetohydrodynamic compressible flow with temperature dependent heat conductivity in a half-line.In particular,the transverse magnetic field is assumed to satisfy the Neumann boundary condition,which was first investigated by Kazhikhov in 1987.We establish the global existence of the unique strong solutions to the MHD equations without any smallness conditions on the initial data.More precisely,our result can be regarded as a natural generalization of Kazhikov’s result for applying the constant heat-conductivity in bounded domains to the degenerate case in unbounded domains.
基金supported by the National Natural Science Foundation of China(Grant No.12172063).
文摘The damage evolution of polycrystalline Al with helium(He)bubbles under strongly decaying shock waves is studied by molecular dynamics simulations.A new damage region is observed near the loading side of the sample,and the evolution characteristics and underlying mechanisms are elucidated.The development of damage in the new damage region begins after complete unloading of the incident shock wave and is further enhanced when the tensile stress arrives later.The damage evolution is completely controlled by the expansion-merging of He bubbles,without nucleation–growth of voids.This new damage region can be divided into two sections,each of which exhibits a unique dominant mechanism.The damage in the section closer to the loading side is due to the reverse velocity gradient formed after complete unloading of the incident shock wave,depending on the rate of decrease and the amplitude of the initial peak pressure.A high initial peak pressure that can lead to melting of material near the loading side is a necessary condition for the formation of the new damage region,since a significant reverse velocity gradient can only be established if melting occurs.The dominant mechanism in the section distant from the loading side is the action of tensile stress,associated with the profile of the incident shock wave upon reaching the free surface,which determines the material phase near the free surface.Moreover,the presence of He bubbles is another critical factor for formation of the new damage region,which does not occur in pure Al samples.
基金the National Natural Science Foundation of China(No.22279070[L.Wang]and U21A20170[X.He])the Ministry of Science and Technology of China(No.2019YFA0705703[L.Wang])。
文摘Lithium-ion batteries(LIBs)face significant limitations in low-temperature environments,with the slow interfacial de-solvation process and the hindered Li+transport through the interphase layer emerging as key obstacles beyond the issue of ionic conductivity.This investigation unveils a novel formulation that constructs an anion-rich solvation sheath within strong solvents,effectively addressing all three of these challenges to bolster low-temperature performance.The developed electrolyte,characterized by an enhanced concentration of contact ion pairs(CIPs)and aggregates(AGGs),facilitates the formation of an inorganic-rich interphase layer on the anode and cathode particles.This promotes de-solvation at low temperatures and stabilizes the electrode-electrolyte interphase.Full cells composed of LiNi_(0.6)Co_(0.2)Mn_(0.2)O_(2)(NCM622)and graphite,when equipped with this electrolyte,showcase remarkable cycle stability and capacity retention,with 93.3% retention after 500 cycles at room temperature(RT)and 95.5%after 120 cycles at -20℃.This study validates the utility of the anion-rich solvation sheath in strong solvents as a strategy for the development of low-temperature electrolytes.
基金supported by the Special Fund for Scientific and Technological Innovation Strategy of Guangdong Province(2022A0505030025)the Science and Technology Fund,FDCT,Macao SAR(0064/2021/A2)
文摘This paper addresses the verification of strong currentstate opacity with respect to real-time observations generated from a discrete-event system that is modeled with time labeled Petri nets. The standard current-state opacity cannot completely characterize higher-level security. To ensure the higher-level security requirements of a time-dependent system, we propose a strong version of opacity known as strong current-state opacity. For any path(state-event sequence with time information)π derived from a real-time observation that ends at a secret state, the strong current-state opacity of the real-time observation signifies that there is a non-secret path with the same real-time observation as π. We propose general and non-secret state class graphs, which characterize the general and non-secret states of time-dependent systems, respectively. To capture the observable behavior of non-secret states, a non-secret observer is proposed.Finally, we develop a structure called a real-time concurrent verifier to verify the strong current-state opacity of time labeled Petri nets. This approach is efficient since the real-time concurrent verifier can be constructed by solving a certain number of linear programming problems.
基金“High precision prestack reverse time depth migration imaging of long array seismic data in the East China Sea Shelf Basin”of the National Natural Science Foundation of China(No.42106207)“Seismic acquisition technology for deep strata under strong shielding layers in the sea and rugged seabed”of Laoshan Laboratory Science and Technology Innovation Project(No.LSKJ202203404)“Research on the compensation methods of the middledeep weak seismic reflections in the South Yellow Sea based on multi-resolution HHT time-frequency analysis”of the National Natural Science Foundation of China(No.42106208).
文摘The seismic data of the Laoshan Uplift in the South Yellow Sea Basin reveal a low signal-tonoise ratio and low refl ection signal energy in the deep Mesozoic–Paleozoic strata.The main reason is that the Mesozoic-Paleozoic marine carbonate rock strata are directly covered by the Cenozoic terrestrial clastic rock strata,which form a strong shielding layer.To obtain the reflection signals of the strata below the strong shielding layer,a one-way wave equation bidirectional illumination analysis of the main observation system parameters was conducted by analyzing the mechanism of the strong shielding layer.Low-frequency seismic sources are assumed to have a high illumination intensity on the reflection layer below the strong shielding layer.Accordingly,optimized acquisition parameter suggestions were proposed,and reacquisition was performed at the existing survey line locations in the Laoshan Uplift area.The imaging of the newly acquired data in the middle and deep layers was drastically improved.It revealed the unconformity between the Sinian and Cambrian under the strong shielding layer.The study yielded new insights into the tectonic and sedimentary evolution of the Lower Paleozoic in the South Yellow Sea.
基金National Natural Science Foundation of China under Grant Nos.52078386 and 52308496SINOMACH Youth Science and Technology Fund under Grant No.QNJJ-PY-2022-02+2 种基金Young Elite Scientists Sponsorship Program under Grant No.BYESS2023432Fund of State Key Laboratory of Precision Blasting and Hubei Key Laboratory of Blasting Engineering,Jianghan University under Grant No.PBSKL2023A9Fund of China Railway Construction Group Co.,Ltd.under Grant No.LX19-04b。
文摘Strong surface impact will produce strong vibration,which will pose a threat to the safety of nearby buried pipelines and other important lifeline projects.Based on the verified numerical method,a comprehensive numerical parameter analysis is conducted on the key influencing factors of the vibration isolation hole(VIH),which include hole diameter,hole net spacing,hole depth,hole number,hole arrangement,and soil parameters.The results indicate that a smaller ratio of net spacing to hole diameter,the deeper the hole,the multi-row hole,the hole adoption of staggered arrangements,and better site soil conditions can enhance the efficiency of the VIH barrier.The average maximum vibration reduction efficiency within the vibration isolation area can reach 42.2%.The vibration safety of adjacent oil pipelines during a dynamic compaction projection was evaluated according to existing standards,and the measurement of the VIH was recommended to reduce excessive vibration.The single-row vibration isolation scheme and three-row staggered arrangement with the same hole parameters are suggested according to different cases.The research findings can serve as a reference for the vibration safety analysis,assessment,and control of adjacent underground facilities under the influence of strong surface impact loads.
文摘This note is to investigate the properties of strongly semipotent rings.It is proved that every strongly semipotent ring is a idempotent unit regular ring,i.e.,there exist a non-zero idempotent e and a unit u such that er=eu for all r∉J(R),where J(R)is the Jacobson radical of ring R.
文摘In 2024,the world witnessed further transformation and instability,marked by protracted and intensified geopolitical conflicts,repeated attempts to decouple and sever supply chains,and the rapid rise of the Global South.It has become all the more clear where the once-in-a-century transformations are heading.In 2024,China acted on the blueprint drawn up at the Third Plenary Session of the 20th Central Committee of the Communist Party of China(CPC),and made big strides in deepening reform comprehensively.Marking the 75th anniversary of the founding of New China,China carried forward its great cause of national development and pressed ahead with Chinese modernization with vigor and determination.
文摘Correction to:Nano-Micro Lett.(2025)17:24 https://doi.org/10.1007/s40820-024-01515-0 Following publication of the original article[1],the authors reported the author list needed to be updated because the last three author names were duplicated.The correct author list has been provided in this Correction.The original article[1]has been corrected.
文摘HE Tangs,a family of three from Hebei Province in north China,were full of gasps of admiration as they went on a Hengqin-Macao bay cruise in southern China.The cruise started from Hengqin,a small island with remarkable economic achievements on the Chinese mainland,and then went past the picturesque Macao Special Administrative Region.The passengers frantically clicked away at the passing landmarks-the 338-meter Macao Tower,one of Macao’s most iconic architectures,the four spectacular sea-crossing bridges connecting Macao Peninsula and Macao’s Taipa Island,and of course the Hong Kong-Zhu-hai-Macao Bridge,the longest bridge-cum-tunnel sea crossing in the world linking Hong Kong with the city of Zhuhai on the mainland.
文摘This article has been compiled and edited by China Report ASEAN based on an interview with the FAO Office of Youth and Women.As the Food and Agriculture Organization of the United Nations(FAO)celebrates its 80th anniversary,the spotlight is shifting from solely honouring its longstanding mission to also highlighting the dynamic participation of youth and women in driving positive changes in agrifood systems.
基金supported by the National Natural Science Foundation of China(Grant Nos.12234020,12450403,and 12374263)。
文摘This letter reports an all-optical measurement of laser electric field based on strong field ionization.By measuring the attosecond transient absorption spectra of krypton ions subjected to strong laser fields,we obtain the time-dependent effective valence-hole population,from which the driving laser waveform is retrieved with particle swarm optimization and genetic algorithm under strong-field approximation.
基金Project(2021RC3003) supported by the Hunan Science and Technology Innovation Talents Program,China。
文摘The present investigation introduces a composite frequency selective Rasorber(CFSR)that demonstrates a wide−1 dB transmission band,two high absorption bands with absorptivity higher than 90%,and large oblique incidence angles up to 60°.The CFSR consists of four functional layers separated by three dielectric slabs,which includes lossless metasurface-Ⅰ(MS-Ⅰ),loss metasurface-Ⅱ(MS-Ⅱ),loss metasurface-Ⅲ(MS-Ⅲ),and a three-dimensional metastructure(3D-MS).MS-Ⅰfunctions as a reflector for two absorption bands with a minimal insertion loss transmission window.MS-Ⅱis designed for high-frequency absorption.MS-Ⅲserves as a low-frequency absorption layer for CFSR and an impedance matching layer for MS-Ⅱ.The design methodologies for the transmission window in MS-III and the introduction of 3D-MS are key to achieving high-performance CFSR.The physical mechanisms of CFSR are explained through equivalent circuit model(ECM)analysis and impedance characterization.Finally,measurement results confirm that the proposed CFSR exhibits a−1 dB transmission band ranging from 8.79 to 10.41 GHz with a minimum insertion loss of 0.44 dB at 9.59 GHz;furthermore,the frequency range where reflection coefficient remains below−10 dB is measured to be between 3.33 and 18.00 GHz,aligning well with simulation outcomes.
基金supported by the National Natural Science Foundation of China(11931010,12226326,12226327)the Key Research Project of Academy for Multidisciplinary Studies,Capital Normal Universitysupported by the Anhui Provincial Natural Science Foundation(2408085QA031).
文摘We consider the Cauchy problem for the three-dimensional pressureless Navier-Stokes/Navier-Stokes system,which consists of the pressureless Navier-Stokes equations for(n,w)coupled with the isentropic compressible Navier-Stokes equations for(ρ,u)through a drag force term n(w−u).We prove the global existence of strong solutions to the coupled system when the initial data are small perturbations of the constant equilibrium state.However,due to the pressureless structure,one can only deal with the density n of the pressureless flow through the transport equation and it is crucial to obtain the exact time-decay rates for the corresponding velocity w of the pressureless flow.To this end,we make use of the spectral analysis,low-high frequency decomposition and time-weighted energy method to deduce the large time behavior of(w,ρ,u)and consequently establish the Lyapunov stability of the density n in Sobolev space.
基金financially supported by the National Natural Science Foundation of China(Nos.22273098,52033001 and 22303032)the Key Project of Anhui Province Science and Technology Innovation Platform(No.S202305a12020030)+1 种基金the Science and Technology Program Project of Zhejiang Province,China(No.2025ZY01057)partially carried out at the USTC Center for Micro and Nanoscale Research and Fabrication。
文摘Strong polyelectrolyte brushes(SPBs)play an important role in enabling material surface functionalization due to their unique stimuli-responsive properties.Although the unexpected pH responsiveness of SPBs has been revealed in the past ten years,it is still unclear if the pH-responsive properties of SPBs are affected by the brush thickness.In this study,we employed the positively charged poly[2-(methacryloyloxy)ethyl]trimethylammonium chloride(PMETAC)and negatively charged sodium poly(styrenesulfonate)(NaPSS)brushes as model systems to explore the effect of thickness on the pH-responsive properties of SPBs.The results demonstrate that the pH-responsive properties of SPBs manifest different dependences on the brush thickness.Specifically,for both PMETAC and NaPSS brushes,the pH-responsive hydration and stiffness are influenced by the thickness,and the pH-responsive wettability and adhesion are almost unaffected by the thickness.This work not only provides a clear understanding of the relationship between the brush thickness and the pH responsiveness of SPBs,but also offers a new method to control the pH-responsive properties of SPBs.
基金financially supported by the Central government guides local science and technology development(CN)(No.[2019]4011)the Construction project of anti-fatigue manufacturing technology innovation ability of key components in aerospace(CN)(No.Qian financial workers[2022]92)+3 种基金the Construction of collaborative innovation platform for fatigue resistance manufacturing technology and quality reliability of key components(CN)(No.2016034)the National natural science foundation of China(CN)(No.12105059)the Guizhou provincial science and technology projects(CN)(No.ZK[2022]097)the Talented program of guizhou university(CN)(No.20210032).
文摘Interface issues have consistently impeded efforts to balance a trade-off between the conductivity functionality and mechanical properties of Cu-matrix composites.Combining first-principles simulations,this study addresses this challenge by preparing a new Cumatrix composite reinforced with MXene,Cu/Ag@MXene composite block(CuAM-CB),which improves the compatibility between metallic Cu and nonmetallic MXene facilitated by Ag modification anchored in situ onto MXene nanosheets,thus realizing element-coupled reinforcement of Ag at the Cu/MXene heterointerfaces.Benefiting from the strong interaction between Ag and C atoms from in situ self-reduction,as well as the excellent compatibility between Ag and Cu atoms(both IB group metals),Ag atoms act as a mediator for the electron transport and mechanical connection at the Cu/MXene heterointerfaces,enabling CuAM-CB to achieve integrated high conductivity functionality(up to 95%IACS)and strong mechanical properties(with a strength-plasticity product of∼18 GPa%).
基金supported by the National Science Foundation of China(22125804 and U24A20534)。
文摘Solid strong base catalysts have high potentials in a variety of reactions due to the advantages of negligible corrosion,easy separation,and high efficiency.However,two issues hinder the applications of such catalysts seriously,namely aggregation of basic sites and leaching of active species during reactions.The development of solid strong base catalysts with active sites that are highly dispersed and stable remains a pronounced challenge.In this work,we employed a two-step reduction strategy to anchor Na single atoms on nitrogen-doped porous carbon(NPC)support,producing a high-performance solid strongly basic catalyst named as Na1/NPC.The alkali precursor NaNO3was converted to Na_(2)O on NPC at 400℃,in which conventional solid base catalyst Na_(2)O/NPC was generated.Upon heat treatment at 850oC,Na_(2)O was further reduced to Na single atoms anchored on NPC,creating Na1/NPC.Experimental studies and theoretical calculations show that Na is structurally embedded on the support in penta-coordinated configuration(Na-C_(3)N_(2)).The synergistic effect of highly dispersed Na atoms and nitrogen doping results in uncommon catalytic activity and stability.In transesterification between methanol and ethylene carbonate to produce dimethyl carbonate(DMC),the yield of DMC reaches 48.4%over Na1/NPC,corresponding to a turnover frequency(TOF)of 129.4 h^(-1),which is far beyond the conventional counterpart Na_(2)O/NPC(63.3 h^(-1))and various reported solid base catalysts.The catalytic activity of Na1/NPC almost keeps constant during five cycles,while 87%of activity is lost for Na_(2)O/NPC due to the leaching of basic sites.This work might offer new ideas for the development of efficient single-atom solid strong base catalysts with high efficiency.
