To research the dynamic mechanical properties and road performances of flame retardant asphalt mortars and mixtures, four different asphalt mortars/mixtures were prepared: a reference group and three asphalt mortars/m...To research the dynamic mechanical properties and road performances of flame retardant asphalt mortars and mixtures, four different asphalt mortars/mixtures were prepared: a reference group and three asphalt mortars/mixtures containing composite flame retardant materials(M-FRs) of different proportions. Temperature sweep, frequency sweep, repeated creep test, force ductility test and bending beam rheological test were carried out to research the dynamic mechanical properties of asphalt mortars containing M-FRs; wheeltracking test, low-temperature bending test and freeze-thaw split test were used to study the road performances of asphalt mixtures containing M-FRs. The results show that high-temperature performances of the three flame retardant asphalt mortars improve greatly, while low-temperature cracking resistances decline. Both hightemperature performances and water stabilities of asphalt mixtures containing M-FRs are quite good and exceed the specification requirements. However, their low-temperature performances decline in different degrees. In summary, besides their good flame retardancy, the flame retardant asphalt mortars and mixtures also exhibit acceptable road performance.展开更多
A lot of experimental methods have been brought forth to assess the dynamic character of the arc welding power source, but up to now, this issue has not been solved very well. In this paper, based on the fuzzy logic r...A lot of experimental methods have been brought forth to assess the dynamic character of the arc welding power source, but up to now, this issue has not been solved very well. In this paper, based on the fuzzy logic reasoning method, a dynamic character assessing model for the arc welding power source was established and used to analyze the dynamic character of the welding power source. Three different types of welding machine have been tested, and the characteristic information of the electrical signals such as re-striking arc voltage, low welding current and so on of the welding process were extracted accurately by using a self-developed welding dynamic arc wavelet analyzer. The experimental results indicate that this model can be used as a new assessing method for the dynamic character of the arc welding power source.展开更多
The enhanced volume of thermal plasma is produced by a multi-arc thermal plasma generator with three pairs of discharge electrodes driven by three directed current power suppliers.Combined with a high-speed camera and...The enhanced volume of thermal plasma is produced by a multi-arc thermal plasma generator with three pairs of discharge electrodes driven by three directed current power suppliers.Combined with a high-speed camera and an oscilloscope,which acquire optical and electric signals synchronously,the dynamic behavior of different kinds of multi-arc discharge adjusted by the electrode arrangement is investigated.Also,the spatial distributions and instability of the arc discharge are analyzed in four electrode configurations using the gray value statistical method.It is found that the cathodic arcs mainly show a contracting state,while the anodic arcs have a trend of transition from shrinkage to a diffusion-like state with the increase of the discharge current.As a result of the adjustment of the electrode configuration,a high temperature region formed in the center of the discharge region in configurations of adjacent electrodes with opposite flow distribution and opposite electrodes with swirl flow distribution due to severe fluctuation of arcs.The discharge voltage rises with increased discharge current in this novel multi-arc plasma generator.It is also found that anode ablation mainly occurs on the conical surface at the copper electrode tip,while cathode erosion mainly occurs on the surface of the inserted tungsten and the nearby copper.展开更多
The dynamical character for a perturbed coupled nonlinear Schrodinger system with periodic boundary condition was studied. First, the dynamical character of perturbed and unperturbed systems on the invariant plane was...The dynamical character for a perturbed coupled nonlinear Schrodinger system with periodic boundary condition was studied. First, the dynamical character of perturbed and unperturbed systems on the invariant plane was analyzed by the spectrum of the linear operator. Then the existence of the locally invariant manifolds was proved by the singular perturbation theory and the fixed-point argument.展开更多
Introduction:Chikungunya virus(CHIKV),an arthropod-borne alphavirus transmitted by Aedes aegypti and Aedes albopictus,causes fever,severe joint pain,and rash.By 2025,it has triggered outbreaks in 119 countries,endange...Introduction:Chikungunya virus(CHIKV),an arthropod-borne alphavirus transmitted by Aedes aegypti and Aedes albopictus,causes fever,severe joint pain,and rash.By 2025,it has triggered outbreaks in 119 countries,endangering 5.5 million people.Recent epidemics in Foshan,China,have strained healthcare systems,underscoring the need to characterize viral load dynamics across infection phases.Methods:We collected 1,156 clinical samples from four Foshan hospitals in July 2025,spanning 6 days before to 12 days after symptom onset.Specimens included serum(904 valid),saliva(22),urine(4),throat swabs(3),and stool(37).CHIKV RNA was quantified via qRT-PCR;timepoints and specimen types with insufficient samples were excluded.Results:Serum showed the highest positivity(90%),followed by saliva(68%),throat swabs(15%),and urine(11%);stool was negative(0%).Serum also had the highest viral loads,confirming its optimal utility.Viral RNA was detectable as early as 1 day presymptom onset(day-1).Days 0–7 post-onset marked explosive replication and elevated loads,representing the optimal sampling window.From Day 8 onward,loads declined,requiring IgG testing to avoid false negatives.Conclusions:Serum is the gold standard for acute CHIKV diagnosis,with superior positivity and viral loads.Pre-symptomatic viral shedding(day-1)supports enhanced port-of-entry screening to intercept imported cases.Days 0–7 post-onset is the optimal sampling window for acute infection.During clearance(day 8+),IgG testing complements molecular diagnostics to reduce gaps.These findings inform evidence-based diagnosis,outbreak control,and resource allocation.展开更多
Dynamical quantum phase transitions(DQPTs),characterized by non-analytic behavior in rate function and abrupt changes in dynamic topological order parameters(DTOPs)over time,have garnered enormous attention in recent ...Dynamical quantum phase transitions(DQPTs),characterized by non-analytic behavior in rate function and abrupt changes in dynamic topological order parameters(DTOPs)over time,have garnered enormous attention in recent decades.However,in non-Hermitian systems,the special biorthogonality of the bases makes the definition of DQPTs complex.In this work,we delve into the comprehensive investigation of self-normal DQPTs(originally used in Hermitian systems)to compare them with their biorthogonal counterpart,within the context of non-Hermitian quantum walks(QWs).We present a detailed analysis of the behaviors of Loschmidt rate functions and DTOPs under these two distinct theoretical approaches.While both self-normal and biorthogonal methods can be used to detect DQPTs in quench dynamics between different topological phases,we theoretically present their differences in the definition of critical momenta and critical times by analyzing the Fisher zeros and fixed points.Finally,we present an experiment that observes both types of DQPTs using one-dimensional discrete-time QWs with single photons.展开更多
Excavation with tunnel boring machine(TBM)can generate vibrations,causing damages to neighbouring buildings and disturbing the residents or the equipment.This problem is particularly challenging in urban areas,where T...Excavation with tunnel boring machine(TBM)can generate vibrations,causing damages to neighbouring buildings and disturbing the residents or the equipment.This problem is particularly challenging in urban areas,where TBMs are increasingly large in diameter and shallow in depth.In response to this problem,four experimental campaigns were carried out in different geotechnical contexts in France.The vibration measurements were acquired on the surface and inside the TBMs.These measurements are also complemented by few data in the literature.An original methodology of signal processing is pro-posed to characterize the amplitude of the particle velocities,as well as the frequency content of the signals to highlight the most energetic bands.The levels of vibrations are also compared with the thresholds existing in various European regulations concerning the impact on neighbouring structures and the disturbance to local residents.展开更多
The flowability of granular material is commonly determined from shear cell tests,but in the real world,the granular flow is quite different in many cases.For this paper,the flowabilities in a narrow channel of five d...The flowability of granular material is commonly determined from shear cell tests,but in the real world,the granular flow is quite different in many cases.For this paper,the flowabilities in a narrow channel of five different granular materials were investigated.The flow parameters of the granular flows were determined to classify the flowabil让ies.Granular flow surface velocities and flow heights and thicknesses were measured,and it was found that the mean shear rates in the linear portions of the velocity profiles in crease with both flow rates and incli nation.A universal parameter,the ratio of the sine of the inclin ation to the shear rate in the linear part of the velocity profile,is proposed as a constant.This constant is independent of particle properties.In addition,a flowability parameter,the ratio of the mean shear rate to the cosine of the inclination,is proposed to characterize the friction between the particles in the flowing granular material.展开更多
There are abundant marine carbonate rock resources in China,which are dominated by fractured-vuggy carbonate oil and gas reservoirs accounting for over two thirds of proved reserves.The fractured-vuggy carbonate conde...There are abundant marine carbonate rock resources in China,which are dominated by fractured-vuggy carbonate oil and gas reservoirs accounting for over two thirds of proved reserves.The fractured-vuggy carbonate condensate gas reservoir in the Tarim Basin is at a burial depth of 4500e7000 m with the characteristics of extremely strong reservoir heterogeneity,complicated and diverse reservoir seepage media,complex fluid properties and quite difficult static characterization,which brings many challenges to reserve evaluation,development plan design and performance analysis.In order to improve the recovery factor of this type of oil and gas reservoir,this paper takes the dynamic characterization to supplement the static characterization and combines each other to improve the accuracy.In addition,based on many years'of dynamic and static research and development practice,the key enhanced gas recovery(EGR)technologies for fractured-vuggy carbonate condensate gas reservoirs are innovatively developed,such as the high-accuracy dynamic characterization technology with dynamic and static iteration for fractured-vuggy body in the strongly attenuated area of desert by taking seismic inversion information as the basis and 3D numerical well test as the core,the multi-target 3D development technology in one well to improve reserve production of fractured-vuggy condensate gas reservoirs,and the gas-lift depressurization EGR technology for fractured-vuggy condensate gas reservoirs.In conclusion,this technological system better solves the key difficulties in the fine characterization of fractured-vuggy body,reserve production improvement and abandonment pressure reduction of well.What's more,it realizes the fine reservoir characterization of fractured zones and feather-shaped fractured zones and the accurate prediction of key development indexes,and increases the deployment success rate of effective wells and efficient wells by 26%compared with that in the initial stage of large-scale productivity construction.To sum up,these technologies provide powerful technical support and reference experience for the scientific and efficient development of fractured-vuggy carbonate condensate gas reservoirs.展开更多
Intermittent convective transport at the edge and in the scrape-off layer （SOL） of EAST was investigated by using fast reciprocating Langmuir probe. Holes, as part of plasma structures, were detected for the first t...Intermittent convective transport at the edge and in the scrape-off layer （SOL） of EAST was investigated by using fast reciprocating Langmuir probe. Holes, as part of plasma structures, were detected for the first time inside the shear layer. The amplitude probability distribution function of the turbulence is strongly skewed, with positive skewed events （＂blobs＂） prevailing in the SOL region and negative skewed events （＂holes＂） dominant inside the shear layer. The statistical properties coincide with previous observations from JET. The generation mechanism of blobs and holes is also discussed. In addition burst structure and dynamics character of them are also presented.展开更多
A new hyperchaos circuit system with simple structure is designed in this paper. It can be implemented with changeable dimensions 3, 5, 7, 9, etc, therefore it can afford different security grades for applications. Th...A new hyperchaos circuit system with simple structure is designed in this paper. It can be implemented with changeable dimensions 3, 5, 7, 9, etc, therefore it can afford different security grades for applications. The dynamic characters of the 7th order circuit have been analyzed as an example. Using the hyperchaos time sequence produced by this circuit as key sequence, the encryption and decryption to digital signals of text and image files have been realized, and the real-time ability has been increased with encrypting digital signals per byte.展开更多
In this paper,operator splitting scheme for dynamic reservoir characterization by binary level set method is employed.For this problem,the absolute permeability of the two-phase porous medium flow can be simulated by ...In this paper,operator splitting scheme for dynamic reservoir characterization by binary level set method is employed.For this problem,the absolute permeability of the two-phase porous medium flow can be simulated by the constrained augmented Lagrangian optimization method with well data and seismic time-lapse data.By transforming the constrained optimization problem in an unconstrained one,the saddle point problem can be solved by Uzawas algorithms with operator splitting scheme,which is based on the essence of binary level set method.Both the simple and complicated numerical examples demonstrate that the given algorithms are stable and efficient and the absolute permeability can be satisfactorily recovered.展开更多
The integration of multiple electrophysiological biomarkers is crucial for monitoring neonatal seizure dynamics.The present study aimed to characterize the temporal dynamics of neonatal seizures by analyzing intrinsic...The integration of multiple electrophysiological biomarkers is crucial for monitoring neonatal seizure dynamics.The present study aimed to characterize the temporal dynamics of neonatal seizures by analyzing intrinsic waveforms of epileptic electroencephalogram(EEG)signals.We proposed a complementary set of methods considering envelope power,focal sharpness changes,and nonlinear patterns of EEG signals of 79 neonates with seizures.Features derived from EEG signals were used as input to the machine learning classifier.All three characteristics were significantly elevated during seizure events,as agreed upon by all viewers(P<0.0001).Envelope power was elevated in the entire seizure period,and the degree of nonlinearity rose at the termination of a seizure event.Epileptic sharpness effectively characterizes an entire seizure event,complementing the role of envelope power in identifying its onset.However,the degree of nonlinearity showed superior discriminability for the termination of a seizure event.The proposed computational methods for intrinsic sharp or nonlinear EEG patterns evolving during neonatal seizure could share some features with envelope power.Current findings may be helpful in developing strategies to improve neonatal seizure monitoring.展开更多
Real-time wide-area environment sensing is crucial for accessing open-world information streams from nature and human society.As a transformative technique distinct from electrical sensors,distributed optical fiber se...Real-time wide-area environment sensing is crucial for accessing open-world information streams from nature and human society.As a transformative technique distinct from electrical sensors,distributed optical fiber sensing especially for Brillouin scattering-based paradigm has shown superior bandwidth,power,and sensing range.Still,it suffers from insufficient resolution and timeliness to characterize remote dynamic events.Here we develop TABS—a transient acoustic wave-based Brillouin optical time domain analysis sensor,supporting long-range highspatiotemporal-resolution distributed sensing.By designing a functionally synergistic sensor architecture,TABS elaborately leverages wideband and time-weighted energy transformation properties of a transient acousto-optic interaction to breaking through Brillouin-energy-utilization-efficiency bottleneck,enabling enhancements in overall sensing performance.In the experiment,TABS has achieved a 37-cm spatial resolution over a 50-km range with 1 to 2 orders of magnitude improvement in temporal resolution compared to prevailing Brillouin sensing approaches.For the first time,TABS is explored for state imaging of evacuated-tube maglev transportation system as an exemplary application,showcasing its feasibility and flexibility for potential open-world applications and large-scale intelligent perception.展开更多
The(3+1)-dimensional Boiti-Leon-Manna-Pempinelli(BLMP)equation serves as a crucial nonlinear evolution equation in mathematical physics,capable of characterizing complex nonlinear dynamic phenomena in three-dimensiona...The(3+1)-dimensional Boiti-Leon-Manna-Pempinelli(BLMP)equation serves as a crucial nonlinear evolution equation in mathematical physics,capable of characterizing complex nonlinear dynamic phenomena in three-dimensional space and one-dimensional time.With broad applications spanning fluid dynamics,shallow water waves,plasma physics,and condensed matter physics,the investigation of its solutions holds significant importance.Traditional analytical methods face limitations due to their dependence on bilinear forms.To overcome this constraint,this letter proposes a novel multi-modal neurosymbolic reasoning intelligent algorithm(MMNRIA)that achieves 100%accurate solutions for nonlinear partial differential equations without requiring bilinear transformations.By synergistically integrating neural networks with symbolic computation,this approach establishes a new paradigm for universal analytical solutions of nonlinear partial differential equations.As a practical demonstration,we successfully derive several exact analytical solutions for the(3+1)-dimensional BLMP equation using MMNRIA.These solutions provide a powerful theoretical framework for studying intricate wave phenomena governed by nonlinearity and dispersion effects in three-dimensional physical space.展开更多
The transmission electron microscope(TEM)is now one of the most powerful tools for structural characterization due to its high spatial resolution,especially with the advent of the spherical aberration corrector.The in...The transmission electron microscope(TEM)is now one of the most powerful tools for structural characterization due to its high spatial resolution,especially with the advent of the spherical aberration corrector.The interaction between electrons and specimens allows tailoring surface structures by electron irradiation.Furthermore,along with the development of special holders and specimen preparation techniques,the structural evolution of surfaces/interfaces can be dynamically monitored under external fields or reaction environments at the nanoscale,which promotes not only the establishment of the relationship between atomic structures and novel properties,but also potential applications in nanodevices.In this report,we review some of our recent results obtained by TEM,including dynamical observation of surface-mediated novel phenomena,controllable fabrication of nanostructures,and some potential applications in nanodevices.展开更多
基金Funded by the National Key Technology R&D Program for the 12th Five-Year Plan(No.2011BAE27B04)
文摘To research the dynamic mechanical properties and road performances of flame retardant asphalt mortars and mixtures, four different asphalt mortars/mixtures were prepared: a reference group and three asphalt mortars/mixtures containing composite flame retardant materials(M-FRs) of different proportions. Temperature sweep, frequency sweep, repeated creep test, force ductility test and bending beam rheological test were carried out to research the dynamic mechanical properties of asphalt mortars containing M-FRs; wheeltracking test, low-temperature bending test and freeze-thaw split test were used to study the road performances of asphalt mixtures containing M-FRs. The results show that high-temperature performances of the three flame retardant asphalt mortars improve greatly, while low-temperature cracking resistances decline. Both hightemperature performances and water stabilities of asphalt mixtures containing M-FRs are quite good and exceed the specification requirements. However, their low-temperature performances decline in different degrees. In summary, besides their good flame retardancy, the flame retardant asphalt mortars and mixtures also exhibit acceptable road performance.
基金This work is supported by Guangdong Natural Science Fund (04020100)
文摘A lot of experimental methods have been brought forth to assess the dynamic character of the arc welding power source, but up to now, this issue has not been solved very well. In this paper, based on the fuzzy logic reasoning method, a dynamic character assessing model for the arc welding power source was established and used to analyze the dynamic character of the welding power source. Three different types of welding machine have been tested, and the characteristic information of the electrical signals such as re-striking arc voltage, low welding current and so on of the welding process were extracted accurately by using a self-developed welding dynamic arc wavelet analyzer. The experimental results indicate that this model can be used as a new assessing method for the dynamic character of the arc welding power source.
基金supported by National Natural Science Foundation of China(No.11875295)the National Key R&D Program of China(No.2019YFC0119000)。
文摘The enhanced volume of thermal plasma is produced by a multi-arc thermal plasma generator with three pairs of discharge electrodes driven by three directed current power suppliers.Combined with a high-speed camera and an oscilloscope,which acquire optical and electric signals synchronously,the dynamic behavior of different kinds of multi-arc discharge adjusted by the electrode arrangement is investigated.Also,the spatial distributions and instability of the arc discharge are analyzed in four electrode configurations using the gray value statistical method.It is found that the cathodic arcs mainly show a contracting state,while the anodic arcs have a trend of transition from shrinkage to a diffusion-like state with the increase of the discharge current.As a result of the adjustment of the electrode configuration,a high temperature region formed in the center of the discharge region in configurations of adjacent electrodes with opposite flow distribution and opposite electrodes with swirl flow distribution due to severe fluctuation of arcs.The discharge voltage rises with increased discharge current in this novel multi-arc plasma generator.It is also found that anode ablation mainly occurs on the conical surface at the copper electrode tip,while cathode erosion mainly occurs on the surface of the inserted tungsten and the nearby copper.
文摘The dynamical character for a perturbed coupled nonlinear Schrodinger system with periodic boundary condition was studied. First, the dynamical character of perturbed and unperturbed systems on the invariant plane was analyzed by the spectrum of the linear operator. Then the existence of the locally invariant manifolds was proved by the singular perturbation theory and the fixed-point argument.
基金Supported by the Guangdong Provincial Center for Disease Control and Prevention Supports Talent Projects(0720240122)the Guangdong Provincial Key Laboratory of Pathogen Detection for Emerging Infectious Disease Response(2023B1212010010).
文摘Introduction:Chikungunya virus(CHIKV),an arthropod-borne alphavirus transmitted by Aedes aegypti and Aedes albopictus,causes fever,severe joint pain,and rash.By 2025,it has triggered outbreaks in 119 countries,endangering 5.5 million people.Recent epidemics in Foshan,China,have strained healthcare systems,underscoring the need to characterize viral load dynamics across infection phases.Methods:We collected 1,156 clinical samples from four Foshan hospitals in July 2025,spanning 6 days before to 12 days after symptom onset.Specimens included serum(904 valid),saliva(22),urine(4),throat swabs(3),and stool(37).CHIKV RNA was quantified via qRT-PCR;timepoints and specimen types with insufficient samples were excluded.Results:Serum showed the highest positivity(90%),followed by saliva(68%),throat swabs(15%),and urine(11%);stool was negative(0%).Serum also had the highest viral loads,confirming its optimal utility.Viral RNA was detectable as early as 1 day presymptom onset(day-1).Days 0–7 post-onset marked explosive replication and elevated loads,representing the optimal sampling window.From Day 8 onward,loads declined,requiring IgG testing to avoid false negatives.Conclusions:Serum is the gold standard for acute CHIKV diagnosis,with superior positivity and viral loads.Pre-symptomatic viral shedding(day-1)supports enhanced port-of-entry screening to intercept imported cases.Days 0–7 post-onset is the optimal sampling window for acute infection.During clearance(day 8+),IgG testing complements molecular diagnostics to reduce gaps.These findings inform evidence-based diagnosis,outbreak control,and resource allocation.
基金supported by the National Key R&D Program of China(Grant No.2023YFA1406701)National Natural Science Foundation of China(Grants No.12025401,92265209,12474352,92476106,and 12088101)Kunkun Wang and Lei Xiao acknowledge support from Beijing National Laboratory for Condensed Matter Physics(No.2024BNLCMPKF010).
文摘Dynamical quantum phase transitions(DQPTs),characterized by non-analytic behavior in rate function and abrupt changes in dynamic topological order parameters(DTOPs)over time,have garnered enormous attention in recent decades.However,in non-Hermitian systems,the special biorthogonality of the bases makes the definition of DQPTs complex.In this work,we delve into the comprehensive investigation of self-normal DQPTs(originally used in Hermitian systems)to compare them with their biorthogonal counterpart,within the context of non-Hermitian quantum walks(QWs).We present a detailed analysis of the behaviors of Loschmidt rate functions and DTOPs under these two distinct theoretical approaches.While both self-normal and biorthogonal methods can be used to detect DQPTs in quench dynamics between different topological phases,we theoretically present their differences in the definition of critical momenta and critical times by analyzing the Fisher zeros and fixed points.Finally,we present an experiment that observes both types of DQPTs using one-dimensional discrete-time QWs with single photons.
文摘Excavation with tunnel boring machine(TBM)can generate vibrations,causing damages to neighbouring buildings and disturbing the residents or the equipment.This problem is particularly challenging in urban areas,where TBMs are increasingly large in diameter and shallow in depth.In response to this problem,four experimental campaigns were carried out in different geotechnical contexts in France.The vibration measurements were acquired on the surface and inside the TBMs.These measurements are also complemented by few data in the literature.An original methodology of signal processing is pro-posed to characterize the amplitude of the particle velocities,as well as the frequency content of the signals to highlight the most energetic bands.The levels of vibrations are also compared with the thresholds existing in various European regulations concerning the impact on neighbouring structures and the disturbance to local residents.
基金the National Natural Science Foundation of China(U1402272)the Fundamental Research Funds for the Central Universitiesfunds from the Shanghai Engineering Research Center of Coal Gasification(18DZ2283900).
文摘The flowability of granular material is commonly determined from shear cell tests,but in the real world,the granular flow is quite different in many cases.For this paper,the flowabilities in a narrow channel of five different granular materials were investigated.The flow parameters of the granular flows were determined to classify the flowabil让ies.Granular flow surface velocities and flow heights and thicknesses were measured,and it was found that the mean shear rates in the linear portions of the velocity profiles in crease with both flow rates and incli nation.A universal parameter,the ratio of the sine of the inclin ation to the shear rate in the linear part of the velocity profile,is proposed as a constant.This constant is independent of particle properties.In addition,a flowability parameter,the ratio of the mean shear rate to the cosine of the inclination,is proposed to characterize the friction between the particles in the flowing granular material.
基金Project supported by the Scientific Research and Technology Development Project of PetroChina Company Limited“Static characterization and dynamic characterization of multi-scale fractured-vug reservoir”(No.2021DJ1501)。
文摘There are abundant marine carbonate rock resources in China,which are dominated by fractured-vuggy carbonate oil and gas reservoirs accounting for over two thirds of proved reserves.The fractured-vuggy carbonate condensate gas reservoir in the Tarim Basin is at a burial depth of 4500e7000 m with the characteristics of extremely strong reservoir heterogeneity,complicated and diverse reservoir seepage media,complex fluid properties and quite difficult static characterization,which brings many challenges to reserve evaluation,development plan design and performance analysis.In order to improve the recovery factor of this type of oil and gas reservoir,this paper takes the dynamic characterization to supplement the static characterization and combines each other to improve the accuracy.In addition,based on many years'of dynamic and static research and development practice,the key enhanced gas recovery(EGR)technologies for fractured-vuggy carbonate condensate gas reservoirs are innovatively developed,such as the high-accuracy dynamic characterization technology with dynamic and static iteration for fractured-vuggy body in the strongly attenuated area of desert by taking seismic inversion information as the basis and 3D numerical well test as the core,the multi-target 3D development technology in one well to improve reserve production of fractured-vuggy condensate gas reservoirs,and the gas-lift depressurization EGR technology for fractured-vuggy condensate gas reservoirs.In conclusion,this technological system better solves the key difficulties in the fine characterization of fractured-vuggy body,reserve production improvement and abandonment pressure reduction of well.What's more,it realizes the fine reservoir characterization of fractured zones and feather-shaped fractured zones and the accurate prediction of key development indexes,and increases the deployment success rate of effective wells and efficient wells by 26%compared with that in the initial stage of large-scale productivity construction.To sum up,these technologies provide powerful technical support and reference experience for the scientific and efficient development of fractured-vuggy carbonate condensate gas reservoirs.
基金supported by National Natural Science Foundation of China(Nos.11075181,10725523,10721505,10990212,10605028)the 973 Programme(No.2010GB104001)
文摘Intermittent convective transport at the edge and in the scrape-off layer （SOL） of EAST was investigated by using fast reciprocating Langmuir probe. Holes, as part of plasma structures, were detected for the first time inside the shear layer. The amplitude probability distribution function of the turbulence is strongly skewed, with positive skewed events （＂blobs＂） prevailing in the SOL region and negative skewed events （＂holes＂） dominant inside the shear layer. The statistical properties coincide with previous observations from JET. The generation mechanism of blobs and holes is also discussed. In addition burst structure and dynamics character of them are also presented.
文摘A new hyperchaos circuit system with simple structure is designed in this paper. It can be implemented with changeable dimensions 3, 5, 7, 9, etc, therefore it can afford different security grades for applications. The dynamic characters of the 7th order circuit have been analyzed as an example. Using the hyperchaos time sequence produced by this circuit as key sequence, the encryption and decryption to digital signals of text and image files have been realized, and the real-time ability has been increased with encrypting digital signals per byte.
基金The author thanks to his supervisor Prof.Lin Qun(Institute of Computational Mathematics,Chinese Academy of Sciences),Prof.Tai Xuecheng,Prof.S.I.Aanonsen(CIPR,University of Bergen)for useful suggestions.This work is also supported by China NSFC(NO.11101084)and NSFC(NO.11101081).
文摘In this paper,operator splitting scheme for dynamic reservoir characterization by binary level set method is employed.For this problem,the absolute permeability of the two-phase porous medium flow can be simulated by the constrained augmented Lagrangian optimization method with well data and seismic time-lapse data.By transforming the constrained optimization problem in an unconstrained one,the saddle point problem can be solved by Uzawas algorithms with operator splitting scheme,which is based on the essence of binary level set method.Both the simple and complicated numerical examples demonstrate that the given algorithms are stable and efficient and the absolute permeability can be satisfactorily recovered.
基金partially supported by the National Natural Science Foundation of China(Nos.62171028 and 62001026)the Beijing Natural Science Foundation(No.L232139)+2 种基金the Open Project of Key Laboratory of Medical Electronics and Digital Health of Zhejiang Province(Nos.MEDH202204 and MEDC202303)the High-Level Fellow Research Fund Program(No.3050012222022)the BIT Research and Innovation Promoting Project(No.2023YCXZ009).
文摘The integration of multiple electrophysiological biomarkers is crucial for monitoring neonatal seizure dynamics.The present study aimed to characterize the temporal dynamics of neonatal seizures by analyzing intrinsic waveforms of epileptic electroencephalogram(EEG)signals.We proposed a complementary set of methods considering envelope power,focal sharpness changes,and nonlinear patterns of EEG signals of 79 neonates with seizures.Features derived from EEG signals were used as input to the machine learning classifier.All three characteristics were significantly elevated during seizure events,as agreed upon by all viewers(P<0.0001).Envelope power was elevated in the entire seizure period,and the degree of nonlinearity rose at the termination of a seizure event.Epileptic sharpness effectively characterizes an entire seizure event,complementing the role of envelope power in identifying its onset.However,the degree of nonlinearity showed superior discriminability for the termination of a seizure event.The proposed computational methods for intrinsic sharp or nonlinear EEG patterns evolving during neonatal seizure could share some features with envelope power.Current findings may be helpful in developing strategies to improve neonatal seizure monitoring.
基金supported in part by National Natural Science Foundation of China(NSFC)under contracts Nos.U23A20376,62431024,61735015,62405153,62205176.
文摘Real-time wide-area environment sensing is crucial for accessing open-world information streams from nature and human society.As a transformative technique distinct from electrical sensors,distributed optical fiber sensing especially for Brillouin scattering-based paradigm has shown superior bandwidth,power,and sensing range.Still,it suffers from insufficient resolution and timeliness to characterize remote dynamic events.Here we develop TABS—a transient acoustic wave-based Brillouin optical time domain analysis sensor,supporting long-range highspatiotemporal-resolution distributed sensing.By designing a functionally synergistic sensor architecture,TABS elaborately leverages wideband and time-weighted energy transformation properties of a transient acousto-optic interaction to breaking through Brillouin-energy-utilization-efficiency bottleneck,enabling enhancements in overall sensing performance.In the experiment,TABS has achieved a 37-cm spatial resolution over a 50-km range with 1 to 2 orders of magnitude improvement in temporal resolution compared to prevailing Brillouin sensing approaches.For the first time,TABS is explored for state imaging of evacuated-tube maglev transportation system as an exemplary application,showcasing its feasibility and flexibility for potential open-world applications and large-scale intelligent perception.
基金supported by the National Natural Science Foundation of China(Grant No.62303289)Tianyuan Fund for Mathematics of the National Natural Science Foundation of China(Grant No.12426105)+3 种基金the Scientific and Technological Innovation Programs(STIP)of Higher Education Institutions in Shanxi(Grant No.2024L022)Fundamental Research Program of Shanxi Province(Grant Nos.202403021222001 and 202203021222003)the“Wen Ying Young Scholars”Talent Project of Shanxi University(Grant Nos.138541088,138541090,and 138541127)Funded by Open Foundation of Hubei Key Laboratory of Applied Mathematics(Hubei University)(Grant No.HBAM202401).
文摘The(3+1)-dimensional Boiti-Leon-Manna-Pempinelli(BLMP)equation serves as a crucial nonlinear evolution equation in mathematical physics,capable of characterizing complex nonlinear dynamic phenomena in three-dimensional space and one-dimensional time.With broad applications spanning fluid dynamics,shallow water waves,plasma physics,and condensed matter physics,the investigation of its solutions holds significant importance.Traditional analytical methods face limitations due to their dependence on bilinear forms.To overcome this constraint,this letter proposes a novel multi-modal neurosymbolic reasoning intelligent algorithm(MMNRIA)that achieves 100%accurate solutions for nonlinear partial differential equations without requiring bilinear transformations.By synergistically integrating neural networks with symbolic computation,this approach establishes a new paradigm for universal analytical solutions of nonlinear partial differential equations.As a practical demonstration,we successfully derive several exact analytical solutions for the(3+1)-dimensional BLMP equation using MMNRIA.These solutions provide a powerful theoretical framework for studying intricate wave phenomena governed by nonlinearity and dispersion effects in three-dimensional physical space.
基金supported by the National Natural Science Fund for Distinguished Young Scholar(Grant No.11525415)the National Natural Science Foundation of China(Grant Nos.51420105003,61274114,11327901,61601116&11674052)
文摘The transmission electron microscope(TEM)is now one of the most powerful tools for structural characterization due to its high spatial resolution,especially with the advent of the spherical aberration corrector.The interaction between electrons and specimens allows tailoring surface structures by electron irradiation.Furthermore,along with the development of special holders and specimen preparation techniques,the structural evolution of surfaces/interfaces can be dynamically monitored under external fields or reaction environments at the nanoscale,which promotes not only the establishment of the relationship between atomic structures and novel properties,but also potential applications in nanodevices.In this report,we review some of our recent results obtained by TEM,including dynamical observation of surface-mediated novel phenomena,controllable fabrication of nanostructures,and some potential applications in nanodevices.
