This paper presents a comprehensive overview of distributed Nash equilibrium(NE)seeking algorithms in non-cooperative games for multiagent systems(MASs),with a distinct emphasis on the dynamic control perspective.It s...This paper presents a comprehensive overview of distributed Nash equilibrium(NE)seeking algorithms in non-cooperative games for multiagent systems(MASs),with a distinct emphasis on the dynamic control perspective.It specifically focuses on the research addressing distributed NE seeking problems in which agents are governed by heterogeneous dynamics.The paper begins by introducing fundamental concepts of general non-cooperative games and the NE,along with definitions of specific game structures such as aggregative games and multi-cluster games.It then systematically reviews existing studies on distributed NE seeking for various classes of MASs from the viewpoint of agent dynamics,including first-order,second-order,high-order,linear,and Euler-Lagrange(EL)systems.Furthermore,the paper highlights practical applications of these theoretical advances in cooperative control scenarios involving autonomous systems with complex dynamics,such as autonomous surface vessels,autonomous aerial vehicles,and other autonomous vehicles.Finally,the paper outlines several promising directions for future research.展开更多
We developed a strategy involving an electroactive biofiltration dynamic membrane(EBDM)for wastewater treatment and membrane fouling mitigation.This approach utilizes a cathode potential within an anaerobic dynamic me...We developed a strategy involving an electroactive biofiltration dynamic membrane(EBDM)for wastewater treatment and membrane fouling mitigation.This approach utilizes a cathode potential within an anaerobic dynamic membrane bioreactor to establish a growth equilibrium electroactive fouling layer.Over a 240 day operation period,the EBDM exhibited outstanding performance,characterized by an ultralow fouling rate(transmembrane pressure<2.5 kPa),superior effluent quality(chemical oxygen demand(COD)removal>93%and turbidity 2 nephelometric turbidity units(NTU)),and a 7.2%increase in methane(CH4)productivity.Morphological analysis revealed that the EBDM acted as a biofilter consisting of a structured,interconnected,multilevel dynamic membrane system with orderly clogging.In the EBDM system,the balanced-growth fouling layers presented fewer biofoulants and looser secondary protein structures.Furthermore,the applied electric field modified the physicochemical properties of the biomass,leading to a decrease in fouling potential.Quartz crystal microbalance with dissipation monitoring analysis indicated that growth equilibrium promoted a looser fouling layer with a lower adsorption mass than did the denser,viscoelastic fouling layer observed in the control reactor.Metagenomic sequencing further demonstrated that continuous electrical stimulation encouraged the development of an electroactive fouling layer with enhanced microbial metabolic functionality on the EBDM.This approach selectively modifies metabolic pathways and increases the degradation of foulants.The EBDM strategy successfully established an ordered-clogging,step-filtered,and balanced-growth electroactive fouling layer,achieving a synergistic effect in reducing membrane fouling,enhancing effluent quality,and improving CH_(4)productivity.展开更多
An optimization study using a comprehensive 3D, multi-phase, non-isothermal model of a PEM （proton exchange membrane） fuel cell that incorporates significant physical processes and key parameters affecting fuel cell...An optimization study using a comprehensive 3D, multi-phase, non-isothermal model of a PEM （proton exchange membrane） fuel cell that incorporates significant physical processes and key parameters affecting fuel cell performance is presented and discussed in detail. The model accounts for both gas and liquid phase in the same computational domain, and thus allows for the implementation of phase change inside the gas diffusion layers. The model includes the transport of gaseous species, liquid water, protons, energy, and water dissolved in the ion-conducting polymer. Water is assumed to be exchanged among three phases： liquid, vapottr, and dissolved, with equilibrium among these phases being assumed. This model also takes into account convection and diffusion of different species in the channels as well as in the porous gas diffusion layer, heat transfer in the solids as well as in the gases, and electrochemical reactions. The results showed that the present multi-phase model is capable of identifying important parameters for the wetting behaviour of the gas diffusion layers and can be used to identify conditions that might lead to the onset of pore plugging, which has a detrimental effect on the fuel cell performance. This model is used to study the effects of several operating, design, and material parameters on fuel cell performance. Detailed analyses of the fuel cell performance under various operating conditions have been conducted and examined.展开更多
This paper summarizes the results of a study of adsorption of sulfur compounds from a high-sulfur feed on improved spherical-shaped nano-AgX zeolite. For this purpose, the nano-AgX zeolite was initially synthesized an...This paper summarizes the results of a study of adsorption of sulfur compounds from a high-sulfur feed on improved spherical-shaped nano-AgX zeolite. For this purpose, the nano-AgX zeolite was initially synthesized and improved with silver compounds such as silver nitrate, and then it was utilized in the adsorption process. In order to investigate the equilibrium and dynamics of the adsorption process, adsorptive desulfurization of real feed(i.e., sour gas condensate from the South Pars gas field) was carried out in batch and continuous processes under several operating conditions; a temperature-dependent Langmuir isotherm model was used to fit the equilibrium data. The value of monolayer adsorption capacity(q_m) and adsorption enthalpy(ΔH) were calculated to be 1.044 mmol/g and 16.8 kJ/mol, respectively. Furthermore, a detailed theoretical model was employed in order to model the breakthrough experiments. The results revealed that an increase in the feed flow rate and 1/T values will cause linear and exponential increase in the total mass transfer coefficient(ks). Isotherm and dynamic breakthrough models were found to be in agreement with the experimental data.展开更多
The carbon dioxide-water system was used to investigate the flowing gas-liquid metastable state. The experiment was carded out in a constant volume vessel with a horizontal circulation pipe and a peristaltic pump forc...The carbon dioxide-water system was used to investigate the flowing gas-liquid metastable state. The experiment was carded out in a constant volume vessel with a horizontal circulation pipe and a peristaltic pump forced CO2 saturated water to flow. The temperature and pressure were recorded. The results showed that some CO2 escaped from the water in the flow process and the pressure increased, indicating that the gas-liquid equilibrium was broken. The amount of escaped CO2 varied with flow speed and reached a limit in a few minutes, entitled dy- namic equilibrium. Temperature and liquid movement played the same important role in breaking the phase equilib- rium. Under the experimental conditions, the ratio of the excessive carbon dioxide in the gas phase to its thermody- namic equilibrium amount in the liquid could achieve 15%.展开更多
Traditional rigid body limit equilibrium method （RBLEM） was adopted for the stability evaluation and analysis of rock slope under earthquake scenario. It is not able to provide the real stress distribution of the st...Traditional rigid body limit equilibrium method （RBLEM） was adopted for the stability evaluation and analysis of rock slope under earthquake scenario. It is not able to provide the real stress distribution of the structure, while the strength reduction method relies on the arbitrary decision on the failure criteria. The dynamic limit equilibrium solution was proposed for the stability analysis of sliding block based on 3-D multi-grid method, by incorporating implicit stepping integration FEM. There are two independent meshes created in the analysis： One original 3-D FEM mesh is for the simulation of target structure and provides the stress time-history, while the other surface grid is for the simulation of sliding surface and could be selected and designed freely. As long as the stress time-history of the geotechnical structure under earthquake scenario is obtained based on 3-D nonlinear dynamic FEM analysis, the time-history of the force on sliding surface could be derived by projecting the stress time-history from 3-D FEM mesh to surface grid. After that, the safety factor time-history of the sliding block will be determined through applying limit equilibrium method. With those information in place, the structure＇s aseismatic stability ean be further studied. The above theory and method were also applied to the aseismatic stability analysis of Dagangshan arch dam＇s right bank high slope and compared with the the result generated by Quasi-static method. The comparative analysis reveals that the method not only raises the FEM＇s capability in accurate simulation of complicated geologic structure, but also increases the flexibility and comprehensiveness of limit equilibrium method. This method is reliable and recommended for further application in other real geotechnical engineering.展开更多
In this paper,we consider distributed Nash equilibrium(NE)seeking in potential games over a multi-agent network,where each agent can not observe the actions of all its rivals.Based on the best response dynamics,we des...In this paper,we consider distributed Nash equilibrium(NE)seeking in potential games over a multi-agent network,where each agent can not observe the actions of all its rivals.Based on the best response dynamics,we design a distributed NE seeking algorithm by incorporating the non-smooth finite-time average tracking dynamics,where each agent only needs to know its own action and exchange information with its neighbours through a communication graph.We give a sufficient condition for the Lipschitz continuity of the best response mapping for potential games,and then prove the convergence of the proposed algorithm based on the Lyapunov theory.Numerical simulations are given to verify the resultandillustrate the effectiveness of the algorithm.展开更多
Researching China's innovative economic and financial innovation issues under the background of the New Normal, we need to carefully analyze the internal structure and interaction of China's macroeconomics.The...Researching China's innovative economic and financial innovation issues under the background of the New Normal, we need to carefully analyze the internal structure and interaction of China's macroeconomics.The computable general equilibrium(CGE) model has outstanding advantages on predicting the external shock influences on economic system, but previous studies on forecast for China's future economy mostly considered a high growth rate which is hard to comply with the New Normal scene. By constructing China's macroeconomic dynamic CGE(DCGE) model and anticipating the economic impact of the New Normal, this paper finds that the New Normal has a certain extent inhibition on China's macro-economy and innovation. However, after adding the research and development(R&D) subsidy policy, the negative impacts of the New Normal on macro-economy can be eliminated to realize the optimization of economic structure. In addition, after combining the financial innovation promoting policy and the Ke Qiang index through the simulation of macro-economy, we find that the quality of economic growth is improved. Finally, we provide the policy recommendations for the realization of an innovative economy under China's New Normal.展开更多
In this paper, a difference scheme with energy dynamic equilibrium (DS-EDE) is presented, which can be used for the simulation of long-term atmosphere and sea motion. Based on three dimensional nonlinear evolution equ...In this paper, a difference scheme with energy dynamic equilibrium (DS-EDE) is presented, which can be used for the simulation of long-term atmosphere and sea motion. Based on three dimensional nonlinear evolution equations for atmosphere and sea motion, a three dimensional compact upwind scheme (CUWS) is constructed, as the basis of the DS-EDE. The DS-EDE satisfies the following condition of energy dynamic equilibrium (EDE): the total work of external forces on the region boundary is equal to the sum of the total effective variation of the kinetic energy and the energy dissipation in the average flow motion and the effective variation of the potential energy per unit time within the region of interest. It really reflects the basic mechanism of the action of external forces and dissipation in atmosphere and sea movement. Therefore, the DS-EDE developed in this paper is a suitable model for simulating long-term atmosphere and sea movement with forcing and dissipation.展开更多
Having criticized the current architecture of Advanced Traveler Information Systems （ATISs）, this work discusses a new base of requirements to develop a new paradigm for traffic information systems. It mainly integr...Having criticized the current architecture of Advanced Traveler Information Systems （ATISs）, this work discusses a new base of requirements to develop a new paradigm for traffic information systems. It mainly integrates three dimensions within a traffic system： drivers＇ pattern of behavior and preferences, urban traffic desires, and capabilities of traffic information service providers. Based on the above, functional segments from several related backgrounds are brought together to structure a new architecture, called Interactive Traveler Information System （ITIS）. The main interactive feature of this new architecture is a two-way communication track between drivers and the traffic information system provider-in fact, a decision on choosing a road at a particular time for an individual will be made based on the utility of both sides. This new configuration consists of driver-side smartphone application, centric traffic prediction, and decision-maker units, which will shape a new approach of decision-making processes. These all work together to satisfy the designated goal of ITIS, which is preserving the Wardrop equilibrium condition in the traffic network level. Finally, we concentrate on a comparison study, which shows a differentiation between performance of the proposed ITIS and the current ATIS model in a real situation. This has been done with simulations of analogical scenarios. The most noticeable advantage of the proposed architecture is not being limited to a saturation limit, and the positive effect of increasing system penetration in the performance of the newly introduced information system. In conclusion, new research subjects are suggested to be carried out.展开更多
We use non-equilibrium molecular dynamics simulations to calculate the self-diffusion coefficient, D, of a Lennard Jones fluid over a wide density and temperature range. The change in self-diffusion coefficient with t...We use non-equilibrium molecular dynamics simulations to calculate the self-diffusion coefficient, D, of a Lennard Jones fluid over a wide density and temperature range. The change in self-diffusion coefficient with temperature decreases by increasing density. For density ρ＊ = ρσ3 = 0.84 we observe a peak at the value of the self-diffusion coefficient and the critical temperature T＊ = kT/ε = 1.25. The value of the self-diffusion coefficient strongly depends on system size. The data of the self-diffusion coefficient are fitted to a simple analytic relation based on hydrodynamic arguments. This correction scales as N-α, where α is an adjustable parameter and N is the number of particles. It is observed that the values of a 〈 1 provide quite a good correction to the simulation data. The system size dependence is very strong for lower densities, but it is not as strong for higher densities. The self-diffusion coefficient calculated with non-equilibrium molecular dynamic simulations at different temperatures and densities is in good agreement with other calculations fronl the literature.展开更多
Water electrolyzers play a crucial role in green hydrogen production.However,their efficiency and scalability are often compromised by bubble dynamics across various scales,from nanoscale to macroscale components.This...Water electrolyzers play a crucial role in green hydrogen production.However,their efficiency and scalability are often compromised by bubble dynamics across various scales,from nanoscale to macroscale components.This review explores multi-scale modeling as a tool to visualize multi-phase flow and improve mass transport in water electrolyzers.At the nanoscale,molecular dynamics(MD)simulations reveal how electrode surface features and wettability influence nanobubble nucleation and stability.Moving to the mesoscale,models such as volume of fluid(VOF)and lattice Boltzmann method(LBM)shed light on bubble transport in porous transport layers(PTLs).These insights inform innovative designs,including gradient porosity and hydrophilic-hydrophobic patterning,aimed at minimizing gas saturation.At the macroscale,VOF simulations elucidate two-phase flow regimes within channels,showing how flow field geometry and wettability affect bubble discharging.Moreover,artificial intelligence(AI)-driven surrogate models expedite the optimization process,allowing for rapid exploration of structural parameters in channel-rib flow fields and porous flow field designs.By integrating these approaches,we can bridge theoretical insights with experimental validation,ultimately enhancing water electrolyzer performance,reducing costs,and advancing affordable,high-efficiency hydrogen production.展开更多
This paper discusses not a point of equilibrium to free system,but a certain family of equilibrium state of dynami- cal system with inputs.This equilibrium state depends on the input,so it is called the dynamic equili...This paper discusses not a point of equilibrium to free system,but a certain family of equilibrium state of dynami- cal system with inputs.This equilibrium state depends on the input,so it is called the dynamic equilibrium state.The expression of the dynamic equilibrium state can be given under some certain condition.With deductions and proofs in linear control system,es- tablish the expression of the dynamic equilibrium state in two cases,where the linear systems are nonsingular or singular.Also pre- sent the concept and the condition of the controllability of the dynamic equilibrium state.The controllability of the dynamic equilib- rium state is different from the controllability of the state to system,but these two are closely related.展开更多
The separation of Ca2+and Mg2+ions from phosphoric acid-nitric acid aqueous solution is very significant for the neutralization process of nitrophosphate fertilizer.This paper studied the adsorption equilibrium,kineti...The separation of Ca2+and Mg2+ions from phosphoric acid-nitric acid aqueous solution is very significant for the neutralization process of nitrophosphate fertilizer.This paper studied the adsorption equilibrium,kinetics,and dynamic separation of Ca2+and Mg2+ions by strong acid cation resin,and the effects of phosphoric acid and nitric acid on the adsorption process were investigated.The results reveal that the adsorption process of Ca2+and Mg2+ions in pure water on resin is in good agreement with the Langmuir isotherm model and their maximal adsorption capacities are 1.86 mmol·g-1 and 1.83 mmol·g-1,respectively.The adsorption kinetics of Ca2+and Mg2+ions on resin fits better with the pseudo-first-order model,and the adsorption equilibrium in pure water is reached within 10 min contact time,while at the present of phosphoric acid,the adsorption rate of Ca2+and Mg2+ions on resin will go down.The dynamic separation experiments demonstrate that the designed column adsorption is able to undertake the separation of metal ions from the mix acids aqueous solution,but the dynamic operation should control the flow rate of mix acid solution.Besides nitric acid solution was proved to be effective to completely regenerate the spent resin and achieve the recyclable operation of separation process.展开更多
In this paper,we consider a networked game with coupled constraints and focus on variational Nash equilibrium seeking.For distributed algorithm design,we eliminate the coupled constraints by employing local Lagrangian...In this paper,we consider a networked game with coupled constraints and focus on variational Nash equilibrium seeking.For distributed algorithm design,we eliminate the coupled constraints by employing local Lagrangian functions and construct exact penalty terms to attain multipliers'optimal consensus,which yields a set of equilibrium conditions without any coupled constraint and consensus constraint.Moreover,these conditions are only based on strategy and multiplier variables,without auxiliary variables.Then,we present a distributed order-reduced dynamics that updates the strategy and multiplier variables with guaranteed convergence.Compared with many other distributed algorithms,our algorithm contains no auxiliary variable,and therefore,it can save computation and communication.展开更多
The challenge of meeting the ever-increasing food demand for the growing population will be further exacerbated by climate change in Ethiopia. This paper presents the simulated economy-wide impacts of climate change o...The challenge of meeting the ever-increasing food demand for the growing population will be further exacerbated by climate change in Ethiopia. This paper presents the simulated economy-wide impacts of climate change on the agriculture sector of Ethiopia using a dynamic computable general equilibrium (CGE) model. The study simulated the scenarios of agricultural productivity change induced by climate change up to the year 2050. At national level, the simulation results suggest that crop production will be adversely affected during the coming four decades and the severity will increase over the time period. Production of teff, maize and sorghum will decline by 25.4, 21.8 and 25.2 percent, respectively by 2050 compared to the base period. Climate change will also cause losses of 31.1 percent agricultural GDP at factor cost by 2050. Climate change affects more the income and consumption of poor rural households than urban rural non-farming households. The reduction in agricultural production will not be evenly distributed across agro ecological zones, and will not all be negative. Among rural residents, climate change impacts tend to hurt the income of the poor more in drought prone regions. Income from labor, land and livestock in moisture sufficient highland cereal-based will decline by 5.1, 8.8 and 15.2 percent in 2050. This study indicated that since climate change is an inevitable phenomenon, the country should start mainstreaming adaptation measures to sustain the overall performance of the economy.展开更多
The thermal conductivity of uranium dioxide in the temperature range of 300–2400 K was estimated by non-equilibrium molecular dynamics calculation using Fourier law.The Kawamura function was adopted as the interatomi...The thermal conductivity of uranium dioxide in the temperature range of 300–2400 K was estimated by non-equilibrium molecular dynamics calculation using Fourier law.The Kawamura function was adopted as the interatomic potential function.The calculated thermal conductivities are found to be strongly dependent on the temperature of the simulation cube.The thermal conductivity simulation results are compared with the experiment results and agreed well with the experimental results when the temperature is above 600 K.The thermal conductivities scale effects are found to be existed in uranium dioxide nanometer thin film.The approximate mean free paths of phonons in different temperatures can be examined.展开更多
Nanofiltration of aqueous NaNO3 solution with a dynamically formed Zr(IV) hydrousoxide-PAA membrane is presented. The practical transpoft coefficients Lp, σ, ω were obtainedusing relationships of the non-equilibrium...Nanofiltration of aqueous NaNO3 solution with a dynamically formed Zr(IV) hydrousoxide-PAA membrane is presented. The practical transpoft coefficients Lp, σ, ω were obtainedusing relationships of the non-equilibrium thermodynamics and were used to calculate thefrictional coefficients of a friction model.展开更多
The dynamic process of non-equilibrium grain boundary segregation of traceboron in Fe-40 percent Ni alloy during cooling and the effect of cooling rate were investigated byboron tracking autoradiography technique. The...The dynamic process of non-equilibrium grain boundary segregation of traceboron in Fe-40 percent Ni alloy during cooling and the effect of cooling rate were investigated byboron tracking autoradiography technique. The results indicate that during cooling process, theamount of segregated boron on grain boundary firstly increases fast, then enters a comparativelyeven increasing stage and increases rapidly again at the third stage. The details of each stagevaried with cooling rate are explained. When the segregation develops to a certain degree, thesegregated boron atoms transform from solute status to precipitate status.展开更多
基金National Natural Science Foundation of China(62325304).
文摘This paper presents a comprehensive overview of distributed Nash equilibrium(NE)seeking algorithms in non-cooperative games for multiagent systems(MASs),with a distinct emphasis on the dynamic control perspective.It specifically focuses on the research addressing distributed NE seeking problems in which agents are governed by heterogeneous dynamics.The paper begins by introducing fundamental concepts of general non-cooperative games and the NE,along with definitions of specific game structures such as aggregative games and multi-cluster games.It then systematically reviews existing studies on distributed NE seeking for various classes of MASs from the viewpoint of agent dynamics,including first-order,second-order,high-order,linear,and Euler-Lagrange(EL)systems.Furthermore,the paper highlights practical applications of these theoretical advances in cooperative control scenarios involving autonomous systems with complex dynamics,such as autonomous surface vessels,autonomous aerial vehicles,and other autonomous vehicles.Finally,the paper outlines several promising directions for future research.
基金Financial support by Natural Science Foundation of China(52430001)is acknowledged.
文摘We developed a strategy involving an electroactive biofiltration dynamic membrane(EBDM)for wastewater treatment and membrane fouling mitigation.This approach utilizes a cathode potential within an anaerobic dynamic membrane bioreactor to establish a growth equilibrium electroactive fouling layer.Over a 240 day operation period,the EBDM exhibited outstanding performance,characterized by an ultralow fouling rate(transmembrane pressure<2.5 kPa),superior effluent quality(chemical oxygen demand(COD)removal>93%and turbidity 2 nephelometric turbidity units(NTU)),and a 7.2%increase in methane(CH4)productivity.Morphological analysis revealed that the EBDM acted as a biofilter consisting of a structured,interconnected,multilevel dynamic membrane system with orderly clogging.In the EBDM system,the balanced-growth fouling layers presented fewer biofoulants and looser secondary protein structures.Furthermore,the applied electric field modified the physicochemical properties of the biomass,leading to a decrease in fouling potential.Quartz crystal microbalance with dissipation monitoring analysis indicated that growth equilibrium promoted a looser fouling layer with a lower adsorption mass than did the denser,viscoelastic fouling layer observed in the control reactor.Metagenomic sequencing further demonstrated that continuous electrical stimulation encouraged the development of an electroactive fouling layer with enhanced microbial metabolic functionality on the EBDM.This approach selectively modifies metabolic pathways and increases the degradation of foulants.The EBDM strategy successfully established an ordered-clogging,step-filtered,and balanced-growth electroactive fouling layer,achieving a synergistic effect in reducing membrane fouling,enhancing effluent quality,and improving CH_(4)productivity.
基金Project supported by the Postgraduate Programs of the International Technological University (ITU), London, UK
文摘An optimization study using a comprehensive 3D, multi-phase, non-isothermal model of a PEM （proton exchange membrane） fuel cell that incorporates significant physical processes and key parameters affecting fuel cell performance is presented and discussed in detail. The model accounts for both gas and liquid phase in the same computational domain, and thus allows for the implementation of phase change inside the gas diffusion layers. The model includes the transport of gaseous species, liquid water, protons, energy, and water dissolved in the ion-conducting polymer. Water is assumed to be exchanged among three phases： liquid, vapottr, and dissolved, with equilibrium among these phases being assumed. This model also takes into account convection and diffusion of different species in the channels as well as in the porous gas diffusion layer, heat transfer in the solids as well as in the gases, and electrochemical reactions. The results showed that the present multi-phase model is capable of identifying important parameters for the wetting behaviour of the gas diffusion layers and can be used to identify conditions that might lead to the onset of pore plugging, which has a detrimental effect on the fuel cell performance. This model is used to study the effects of several operating, design, and material parameters on fuel cell performance. Detailed analyses of the fuel cell performance under various operating conditions have been conducted and examined.
文摘This paper summarizes the results of a study of adsorption of sulfur compounds from a high-sulfur feed on improved spherical-shaped nano-AgX zeolite. For this purpose, the nano-AgX zeolite was initially synthesized and improved with silver compounds such as silver nitrate, and then it was utilized in the adsorption process. In order to investigate the equilibrium and dynamics of the adsorption process, adsorptive desulfurization of real feed(i.e., sour gas condensate from the South Pars gas field) was carried out in batch and continuous processes under several operating conditions; a temperature-dependent Langmuir isotherm model was used to fit the equilibrium data. The value of monolayer adsorption capacity(q_m) and adsorption enthalpy(ΔH) were calculated to be 1.044 mmol/g and 16.8 kJ/mol, respectively. Furthermore, a detailed theoretical model was employed in order to model the breakthrough experiments. The results revealed that an increase in the feed flow rate and 1/T values will cause linear and exponential increase in the total mass transfer coefficient(ks). Isotherm and dynamic breakthrough models were found to be in agreement with the experimental data.
基金Supported by the NationaJ Natural Science Foundation of China （21106176）, President Fund of GUCAS （Y15101JY00）, China Postdoctoral Science Foundation （2012T50155） and National Basic Research Program of China （2009CB219903）.
文摘The carbon dioxide-water system was used to investigate the flowing gas-liquid metastable state. The experiment was carded out in a constant volume vessel with a horizontal circulation pipe and a peristaltic pump forced CO2 saturated water to flow. The temperature and pressure were recorded. The results showed that some CO2 escaped from the water in the flow process and the pressure increased, indicating that the gas-liquid equilibrium was broken. The amount of escaped CO2 varied with flow speed and reached a limit in a few minutes, entitled dy- namic equilibrium. Temperature and liquid movement played the same important role in breaking the phase equilib- rium. Under the experimental conditions, the ratio of the excessive carbon dioxide in the gas phase to its thermody- namic equilibrium amount in the liquid could achieve 15%.
基金Project(2013-KY-2) supported by the State Key Laboratory of Hydroscience and Engineering of Hydroscience, ChinaProject(50925931)supported by the National Funds for Distinguished Young Scientists, China
文摘Traditional rigid body limit equilibrium method （RBLEM） was adopted for the stability evaluation and analysis of rock slope under earthquake scenario. It is not able to provide the real stress distribution of the structure, while the strength reduction method relies on the arbitrary decision on the failure criteria. The dynamic limit equilibrium solution was proposed for the stability analysis of sliding block based on 3-D multi-grid method, by incorporating implicit stepping integration FEM. There are two independent meshes created in the analysis： One original 3-D FEM mesh is for the simulation of target structure and provides the stress time-history, while the other surface grid is for the simulation of sliding surface and could be selected and designed freely. As long as the stress time-history of the geotechnical structure under earthquake scenario is obtained based on 3-D nonlinear dynamic FEM analysis, the time-history of the force on sliding surface could be derived by projecting the stress time-history from 3-D FEM mesh to surface grid. After that, the safety factor time-history of the sliding block will be determined through applying limit equilibrium method. With those information in place, the structure＇s aseismatic stability ean be further studied. The above theory and method were also applied to the aseismatic stability analysis of Dagangshan arch dam＇s right bank high slope and compared with the the result generated by Quasi-static method. The comparative analysis reveals that the method not only raises the FEM＇s capability in accurate simulation of complicated geologic structure, but also increases the flexibility and comprehensiveness of limit equilibrium method. This method is reliable and recommended for further application in other real geotechnical engineering.
基金This work was supported by the Shanghai Sailing Program(No.20YF1453000)the Fundamental Research Funds for the Central Universities(No.22120200048).
文摘In this paper,we consider distributed Nash equilibrium(NE)seeking in potential games over a multi-agent network,where each agent can not observe the actions of all its rivals.Based on the best response dynamics,we design a distributed NE seeking algorithm by incorporating the non-smooth finite-time average tracking dynamics,where each agent only needs to know its own action and exchange information with its neighbours through a communication graph.We give a sufficient condition for the Lipschitz continuity of the best response mapping for potential games,and then prove the convergence of the proposed algorithm based on the Lyapunov theory.Numerical simulations are given to verify the resultandillustrate the effectiveness of the algorithm.
基金the National Natural Science Foundation of China(Nos.71373153,71262022 and 71003068)the Shanghai Philosophy and Social Science Fund Project(No.2014BJB001)the“Shuguang Program”Supported by Shanghai Education Development Foundation and Shanghai Municipal Education Commission(No.14SG32)
文摘Researching China's innovative economic and financial innovation issues under the background of the New Normal, we need to carefully analyze the internal structure and interaction of China's macroeconomics.The computable general equilibrium(CGE) model has outstanding advantages on predicting the external shock influences on economic system, but previous studies on forecast for China's future economy mostly considered a high growth rate which is hard to comply with the New Normal scene. By constructing China's macroeconomic dynamic CGE(DCGE) model and anticipating the economic impact of the New Normal, this paper finds that the New Normal has a certain extent inhibition on China's macro-economy and innovation. However, after adding the research and development(R&D) subsidy policy, the negative impacts of the New Normal on macro-economy can be eliminated to realize the optimization of economic structure. In addition, after combining the financial innovation promoting policy and the Ke Qiang index through the simulation of macro-economy, we find that the quality of economic growth is improved. Finally, we provide the policy recommendations for the realization of an innovative economy under China's New Normal.
基金This study was supported by China Institute for Radiation Protection,partly by State Key Laboratory of Numerical Modeling for Atmosphenc Sciences and Geophysical Fluid Dynamics.
文摘In this paper, a difference scheme with energy dynamic equilibrium (DS-EDE) is presented, which can be used for the simulation of long-term atmosphere and sea motion. Based on three dimensional nonlinear evolution equations for atmosphere and sea motion, a three dimensional compact upwind scheme (CUWS) is constructed, as the basis of the DS-EDE. The DS-EDE satisfies the following condition of energy dynamic equilibrium (EDE): the total work of external forces on the region boundary is equal to the sum of the total effective variation of the kinetic energy and the energy dissipation in the average flow motion and the effective variation of the potential energy per unit time within the region of interest. It really reflects the basic mechanism of the action of external forces and dissipation in atmosphere and sea movement. Therefore, the DS-EDE developed in this paper is a suitable model for simulating long-term atmosphere and sea movement with forcing and dissipation.
文摘Having criticized the current architecture of Advanced Traveler Information Systems （ATISs）, this work discusses a new base of requirements to develop a new paradigm for traffic information systems. It mainly integrates three dimensions within a traffic system： drivers＇ pattern of behavior and preferences, urban traffic desires, and capabilities of traffic information service providers. Based on the above, functional segments from several related backgrounds are brought together to structure a new architecture, called Interactive Traveler Information System （ITIS）. The main interactive feature of this new architecture is a two-way communication track between drivers and the traffic information system provider-in fact, a decision on choosing a road at a particular time for an individual will be made based on the utility of both sides. This new configuration consists of driver-side smartphone application, centric traffic prediction, and decision-maker units, which will shape a new approach of decision-making processes. These all work together to satisfy the designated goal of ITIS, which is preserving the Wardrop equilibrium condition in the traffic network level. Finally, we concentrate on a comparison study, which shows a differentiation between performance of the proposed ITIS and the current ATIS model in a real situation. This has been done with simulations of analogical scenarios. The most noticeable advantage of the proposed architecture is not being limited to a saturation limit, and the positive effect of increasing system penetration in the performance of the newly introduced information system. In conclusion, new research subjects are suggested to be carried out.
基金supported by the National Natural Science Foundation of China (Grant No. 51076128)the National High Technology Research and Development Program of China (Grant No. 2009AA05Z107)
文摘We use non-equilibrium molecular dynamics simulations to calculate the self-diffusion coefficient, D, of a Lennard Jones fluid over a wide density and temperature range. The change in self-diffusion coefficient with temperature decreases by increasing density. For density ρ＊ = ρσ3 = 0.84 we observe a peak at the value of the self-diffusion coefficient and the critical temperature T＊ = kT/ε = 1.25. The value of the self-diffusion coefficient strongly depends on system size. The data of the self-diffusion coefficient are fitted to a simple analytic relation based on hydrodynamic arguments. This correction scales as N-α, where α is an adjustable parameter and N is the number of particles. It is observed that the values of a 〈 1 provide quite a good correction to the simulation data. The system size dependence is very strong for lower densities, but it is not as strong for higher densities. The self-diffusion coefficient calculated with non-equilibrium molecular dynamic simulations at different temperatures and densities is in good agreement with other calculations fronl the literature.
基金supported by a grant from the Research Grants Council of the Hong Kong Special Administrative Region,China(Project No.15308024)a grant from Research Centre for Carbon-Strategic Catalysis,The Hong Kong Polytechnic University(CE2X).
文摘Water electrolyzers play a crucial role in green hydrogen production.However,their efficiency and scalability are often compromised by bubble dynamics across various scales,from nanoscale to macroscale components.This review explores multi-scale modeling as a tool to visualize multi-phase flow and improve mass transport in water electrolyzers.At the nanoscale,molecular dynamics(MD)simulations reveal how electrode surface features and wettability influence nanobubble nucleation and stability.Moving to the mesoscale,models such as volume of fluid(VOF)and lattice Boltzmann method(LBM)shed light on bubble transport in porous transport layers(PTLs).These insights inform innovative designs,including gradient porosity and hydrophilic-hydrophobic patterning,aimed at minimizing gas saturation.At the macroscale,VOF simulations elucidate two-phase flow regimes within channels,showing how flow field geometry and wettability affect bubble discharging.Moreover,artificial intelligence(AI)-driven surrogate models expedite the optimization process,allowing for rapid exploration of structural parameters in channel-rib flow fields and porous flow field designs.By integrating these approaches,we can bridge theoretical insights with experimental validation,ultimately enhancing water electrolyzer performance,reducing costs,and advancing affordable,high-efficiency hydrogen production.
基金Supported by the National Science Foundation of China(60274056)
文摘This paper discusses not a point of equilibrium to free system,but a certain family of equilibrium state of dynami- cal system with inputs.This equilibrium state depends on the input,so it is called the dynamic equilibrium state.The expression of the dynamic equilibrium state can be given under some certain condition.With deductions and proofs in linear control system,es- tablish the expression of the dynamic equilibrium state in two cases,where the linear systems are nonsingular or singular.Also pre- sent the concept and the condition of the controllability of the dynamic equilibrium state.The controllability of the dynamic equilib- rium state is different from the controllability of the state to system,but these two are closely related.
基金Supported by a grant from Tianji Coal Chemical Group Co.Ltd.(Project no.2012-1978)Shenzhen Batian Ecological Engineering Co.,Ltd.(Project no.2013-0909).
文摘The separation of Ca2+and Mg2+ions from phosphoric acid-nitric acid aqueous solution is very significant for the neutralization process of nitrophosphate fertilizer.This paper studied the adsorption equilibrium,kinetics,and dynamic separation of Ca2+and Mg2+ions by strong acid cation resin,and the effects of phosphoric acid and nitric acid on the adsorption process were investigated.The results reveal that the adsorption process of Ca2+and Mg2+ions in pure water on resin is in good agreement with the Langmuir isotherm model and their maximal adsorption capacities are 1.86 mmol·g-1 and 1.83 mmol·g-1,respectively.The adsorption kinetics of Ca2+and Mg2+ions on resin fits better with the pseudo-first-order model,and the adsorption equilibrium in pure water is reached within 10 min contact time,while at the present of phosphoric acid,the adsorption rate of Ca2+and Mg2+ions on resin will go down.The dynamic separation experiments demonstrate that the designed column adsorption is able to undertake the separation of metal ions from the mix acids aqueous solution,but the dynamic operation should control the flow rate of mix acid solution.Besides nitric acid solution was proved to be effective to completely regenerate the spent resin and achieve the recyclable operation of separation process.
基金supported in part by the National Key Research and Development Program of China under grant 2022YFA1004700in part by the Natural Science Foundation of China under grant 72171171in part by Shanghai Municipal Science and Technology Major Project under grant 2021SHZDZX0100.
文摘In this paper,we consider a networked game with coupled constraints and focus on variational Nash equilibrium seeking.For distributed algorithm design,we eliminate the coupled constraints by employing local Lagrangian functions and construct exact penalty terms to attain multipliers'optimal consensus,which yields a set of equilibrium conditions without any coupled constraint and consensus constraint.Moreover,these conditions are only based on strategy and multiplier variables,without auxiliary variables.Then,we present a distributed order-reduced dynamics that updates the strategy and multiplier variables with guaranteed convergence.Compared with many other distributed algorithms,our algorithm contains no auxiliary variable,and therefore,it can save computation and communication.
文摘The challenge of meeting the ever-increasing food demand for the growing population will be further exacerbated by climate change in Ethiopia. This paper presents the simulated economy-wide impacts of climate change on the agriculture sector of Ethiopia using a dynamic computable general equilibrium (CGE) model. The study simulated the scenarios of agricultural productivity change induced by climate change up to the year 2050. At national level, the simulation results suggest that crop production will be adversely affected during the coming four decades and the severity will increase over the time period. Production of teff, maize and sorghum will decline by 25.4, 21.8 and 25.2 percent, respectively by 2050 compared to the base period. Climate change will also cause losses of 31.1 percent agricultural GDP at factor cost by 2050. Climate change affects more the income and consumption of poor rural households than urban rural non-farming households. The reduction in agricultural production will not be evenly distributed across agro ecological zones, and will not all be negative. Among rural residents, climate change impacts tend to hurt the income of the poor more in drought prone regions. Income from labor, land and livestock in moisture sufficient highland cereal-based will decline by 5.1, 8.8 and 15.2 percent in 2050. This study indicated that since climate change is an inevitable phenomenon, the country should start mainstreaming adaptation measures to sustain the overall performance of the economy.
基金Supported by the Dean Fund of Graduate University of Chinese Academy of Sciences(085101DM03)
文摘The thermal conductivity of uranium dioxide in the temperature range of 300–2400 K was estimated by non-equilibrium molecular dynamics calculation using Fourier law.The Kawamura function was adopted as the interatomic potential function.The calculated thermal conductivities are found to be strongly dependent on the temperature of the simulation cube.The thermal conductivity simulation results are compared with the experiment results and agreed well with the experimental results when the temperature is above 600 K.The thermal conductivities scale effects are found to be existed in uranium dioxide nanometer thin film.The approximate mean free paths of phonons in different temperatures can be examined.
文摘Nanofiltration of aqueous NaNO3 solution with a dynamically formed Zr(IV) hydrousoxide-PAA membrane is presented. The practical transpoft coefficients Lp, σ, ω were obtainedusing relationships of the non-equilibrium thermodynamics and were used to calculate thefrictional coefficients of a friction model.
基金This work was financially supported by the Projects of Development of the State Key Fundamental Research(National 973 Project)(No.G19980601507).]
文摘The dynamic process of non-equilibrium grain boundary segregation of traceboron in Fe-40 percent Ni alloy during cooling and the effect of cooling rate were investigated byboron tracking autoradiography technique. The results indicate that during cooling process, theamount of segregated boron on grain boundary firstly increases fast, then enters a comparativelyeven increasing stage and increases rapidly again at the third stage. The details of each stagevaried with cooling rate are explained. When the segregation develops to a certain degree, thesegregated boron atoms transform from solute status to precipitate status.
