In this paper,we study the asymptotic dynamics of a single-species model with resource-dependent dispersal in one dimension.To overcome the analytical difficulties brought by the resource-dependent dispersal,we use th...In this paper,we study the asymptotic dynamics of a single-species model with resource-dependent dispersal in one dimension.To overcome the analytical difficulties brought by the resource-dependent dispersal,we use the idea of changing variables to transform the model into a uniform dispersal one.Then the existence and uniqueness of positive stationary solution to the model can be verified by the squeezing argument,where the solution plays a crucial role in later analyses.Moreover,the asymptotic behavior of solutions to the model is obtained by the upper-lower solutions method.The result indicates that the solutions of the model converge to the corresponding positive stationary solution locally uniformly in one dimension as time goes to infinity.展开更多
The possible place to search for exotic states in J/ψ hadronic decays is in J/ψ →ρρπ. Because of the symmetry of identical particle and the symmetry of isospin, the physical analysis on this channel is quite com...The possible place to search for exotic states in J/ψ hadronic decays is in J/ψ →ρρπ. Because of the symmetry of identical particle and the symmetry of isospin, the physical analysis on this channel is quite complicated. In this paper, the method to use the partial wave analysis based on covariant helicity amplitude analysis to study the invariant mass spectrum of ρρπ and to find the evidence of exotic states in ρρπ spectrum is discussed. The decay amplitude for the decay sequence J/ψ→ρX, X →ρπ is given first. Then we discuss how to realize the identical particle symmetry and the isospin symmetry in the decay amplitude, which is the key point in the analysis of this channel. Then the total decay amplitude of this channel including all decay components is given. After that, how to identify the exotic states in the ρρπ spectrum is discussed. What is discussed in this paper is the theoretical basis on experimentally searching for exotic states at BEPC/BES.展开更多
Quantum entanglement dynamics of two Tavis-Cummings atoms interacting with the quantum light sourcesin a cavity is investigated.The results show the phenomenon that the concurrence disappears abruptly in a finite time...Quantum entanglement dynamics of two Tavis-Cummings atoms interacting with the quantum light sourcesin a cavity is investigated.The results show the phenomenon that the concurrence disappears abruptly in a finite time,which depends on the initial atomic states and the properties of squeezed states.We find that there are two decoherencefreestates in squeezed vacuum fields:one is the singlet state,and the other entangled state is the state that combinesboth excited states and ground states with a relative phase being equal to the phase of the squeezed state.展开更多
The inverse problems of wave equation to recover unknown space-time dependent functions of wave speed and wave source are solved in this paper, without needing of initial conditions and no internal measurement of data...The inverse problems of wave equation to recover unknown space-time dependent functions of wave speed and wave source are solved in this paper, without needing of initial conditions and no internal measurement of data being required. After a homogenization technique, a sequence of spatial boundary functions at least the fourth-order polynomials are derived, which satisfy the homogeneous boundary conditions. The boundary functions and the zero element constitute a linear space, and then a new boundary functional is proved in the linear space, of which the energy is preserved for each dynamic energetic boundary function. The linear systems and iterative algorithms used to recover unknown wave speed and wave source functions with the dynamic energetic boundary functions as bases are developed, which converge fast at each time step. The input data are parsimonious, merely the measured boundary strains and the boundary values and slopes of unknown functions to be recovered. The accuracy and robustness of present methods are confirmed by comparing exact solutions with estimated results under large noises up to 20%.展开更多
The main objective of the present paper is to determine the potential impact the qualitative and quantitative tendencies in the labor market on the decisions which influence the design of monetary policy worldwide. Th...The main objective of the present paper is to determine the potential impact the qualitative and quantitative tendencies in the labor market on the decisions which influence the design of monetary policy worldwide. The analysis is focused on how human resources and phenomena associated with them could influence potential growth and, further on, how they can impact monetary policy decisions at national level for European countries outside the euro area and at ECB level for the euro zone countries. Moreover, the paper will envisage potential macroeconomic reactions （monetary decisions herewith included） to human resources dynamics. The economic variations are regarded through the perspective of growth potential shown by the Research ＆ Development sector and also through the effects of labor force migration. The analysis of statistical data aims at pointing out the different economic perspectives in the European Union, the United States, and Japan, also considering the disparities between EU member states. The analysis is completed by the use of the ranking method, the conclusions stating once more the crucial importance of the human factor in drawing monetary policy decisions展开更多
Outbursts of methane and rocks are, similarly to rock bursts, the biggest hazards in deep mines and are equally difficult to predict. The violent process of the outburst itself, along with the scale and range of hazar...Outbursts of methane and rocks are, similarly to rock bursts, the biggest hazards in deep mines and are equally difficult to predict. The violent process of the outburst itself, along with the scale and range of hazards following the rapid discharge of gas and rocks, requires solutions which would enable quick and unambiguous detection of the hazard, immediate power supply cut-off and evacuation of personnel from potentially hazardous areas. For this purpose, an integrated outburst detector was developed. Assumed functions of the sensor which was equipped with three measuring and detection elements： a chamber for constant measurement of methane concentration, pressure sensor and microphone. Tests of the sensor model were carried out to estimate the parameters which characterize the dynamic properties of the sensor. Given the impossibility of carrying out the full scale experimental outburst, the sensor was tested during the methane and coal dust explosions in the testing gallery at KD Barbara. The obtained results proved that the applied solutions have been appropriate.展开更多
An inverse system method based optimal control strategy was proposed for the shunt hybrid active power filter （SHAPF） to enhance its harmonic elimination performance. Based on the inverse system method, the d-axis a...An inverse system method based optimal control strategy was proposed for the shunt hybrid active power filter （SHAPF） to enhance its harmonic elimination performance. Based on the inverse system method, the d-axis and q-axis current dynamics of the SHAPF system were decoupled and linearized into two pseudolinear subsystems. Then, an optimal feedback controUer was designed for the pseudolinear system, and the stability condition of the resulting zero dynamics was presented. Under the control strategy, the current dynamics can asymptotically converge to their reference states and the zero dynamics can be bounded. Simulation results show that the proposed control strategy is robust against load variations and system parameter mismatches, its steady-state performance is better than that of the traditional linear control strategy.展开更多
The optimization of the control strategy of a plug-in hybrid electric bus(PHEB) for the repeatedly driven bus route is a key technique to improve the fuel economy. The widely used rule-based(RB) control strategy is la...The optimization of the control strategy of a plug-in hybrid electric bus(PHEB) for the repeatedly driven bus route is a key technique to improve the fuel economy. The widely used rule-based(RB) control strategy is lacking in the global optimization property, while the global optimization algorithms have an unacceptable computation complexity for real-time application. Therefore, a novel hybrid dynamic programming-rule based(DPRB) algorithm is brought forward to solve the global energy optimization problem in a real-time controller of PHEB. Firstly, a control grid is built up for a given typical city bus route, according to the station locations and discrete levels of battery state of charge(SOC). Moreover, the decision variables for the energy optimization at each point of the control grid might be deduced from an off-line dynamic programming(DP) with the historical running information of the driving cycle. Meanwhile, the genetic algorithm(GA) is adopted to replace the quantization process of DP permissible control set to reduce the computation burden. Secondly, with the optimized decision variables as control parameters according to the position and battery SOC of a PHEB, a RB control is used as an implementable controller for the energy management. Simulation results demonstrate that the proposed DPRB might distribute electric energy more reasonably throughout the bus route, compared with the optimized RB. The proposed hybrid algorithm might give a practicable solution, which is a tradeoff between the applicability of RB and the global optimization property of DP.展开更多
基金supported by the National Natural Science Foundation of China (Nos.12301101,12101121)the Guangdong Basic and Applied Basic Research Foundation (Nos.2022A1515110019,2020A1515110585)。
文摘In this paper,we study the asymptotic dynamics of a single-species model with resource-dependent dispersal in one dimension.To overcome the analytical difficulties brought by the resource-dependent dispersal,we use the idea of changing variables to transform the model into a uniform dispersal one.Then the existence and uniqueness of positive stationary solution to the model can be verified by the squeezing argument,where the solution plays a crucial role in later analyses.Moreover,the asymptotic behavior of solutions to the model is obtained by the upper-lower solutions method.The result indicates that the solutions of the model converge to the corresponding positive stationary solution locally uniformly in one dimension as time goes to infinity.
基金The project supported in part by National Natural Science Foundation of China under Grant Nos, 10575002, 10421503, 10491306, and 10491300.Acknowledgments The authors acknowledge helpful discussions with H.Q Zheng and X.Y. Shen.
文摘The possible place to search for exotic states in J/ψ hadronic decays is in J/ψ →ρρπ. Because of the symmetry of identical particle and the symmetry of isospin, the physical analysis on this channel is quite complicated. In this paper, the method to use the partial wave analysis based on covariant helicity amplitude analysis to study the invariant mass spectrum of ρρπ and to find the evidence of exotic states in ρρπ spectrum is discussed. The decay amplitude for the decay sequence J/ψ→ρX, X →ρπ is given first. Then we discuss how to realize the identical particle symmetry and the isospin symmetry in the decay amplitude, which is the key point in the analysis of this channel. Then the total decay amplitude of this channel including all decay components is given. After that, how to identify the exotic states in the ρρπ spectrum is discussed. What is discussed in this paper is the theoretical basis on experimentally searching for exotic states at BEPC/BES.
基金Supported by the National Natural Science Foundation of China under Grant Nos. 10974125, 60978017, and 60821004in part by the Educational Committee of Fujian Province (JA09041)Fujian Normal University (2008100220)
文摘Quantum entanglement dynamics of two Tavis-Cummings atoms interacting with the quantum light sourcesin a cavity is investigated.The results show the phenomenon that the concurrence disappears abruptly in a finite time,which depends on the initial atomic states and the properties of squeezed states.We find that there are two decoherencefreestates in squeezed vacuum fields:one is the singlet state,and the other entangled state is the state that combinesboth excited states and ground states with a relative phase being equal to the phase of the squeezed state.
文摘The inverse problems of wave equation to recover unknown space-time dependent functions of wave speed and wave source are solved in this paper, without needing of initial conditions and no internal measurement of data being required. After a homogenization technique, a sequence of spatial boundary functions at least the fourth-order polynomials are derived, which satisfy the homogeneous boundary conditions. The boundary functions and the zero element constitute a linear space, and then a new boundary functional is proved in the linear space, of which the energy is preserved for each dynamic energetic boundary function. The linear systems and iterative algorithms used to recover unknown wave speed and wave source functions with the dynamic energetic boundary functions as bases are developed, which converge fast at each time step. The input data are parsimonious, merely the measured boundary strains and the boundary values and slopes of unknown functions to be recovered. The accuracy and robustness of present methods are confirmed by comparing exact solutions with estimated results under large noises up to 20%.
文摘The main objective of the present paper is to determine the potential impact the qualitative and quantitative tendencies in the labor market on the decisions which influence the design of monetary policy worldwide. The analysis is focused on how human resources and phenomena associated with them could influence potential growth and, further on, how they can impact monetary policy decisions at national level for European countries outside the euro area and at ECB level for the euro zone countries. Moreover, the paper will envisage potential macroeconomic reactions （monetary decisions herewith included） to human resources dynamics. The economic variations are regarded through the perspective of growth potential shown by the Research ＆ Development sector and also through the effects of labor force migration. The analysis of statistical data aims at pointing out the different economic perspectives in the European Union, the United States, and Japan, also considering the disparities between EU member states. The analysis is completed by the use of the ranking method, the conclusions stating once more the crucial importance of the human factor in drawing monetary policy decisions
文摘Outbursts of methane and rocks are, similarly to rock bursts, the biggest hazards in deep mines and are equally difficult to predict. The violent process of the outburst itself, along with the scale and range of hazards following the rapid discharge of gas and rocks, requires solutions which would enable quick and unambiguous detection of the hazard, immediate power supply cut-off and evacuation of personnel from potentially hazardous areas. For this purpose, an integrated outburst detector was developed. Assumed functions of the sensor which was equipped with three measuring and detection elements： a chamber for constant measurement of methane concentration, pressure sensor and microphone. Tests of the sensor model were carried out to estimate the parameters which characterize the dynamic properties of the sensor. Given the impossibility of carrying out the full scale experimental outburst, the sensor was tested during the methane and coal dust explosions in the testing gallery at KD Barbara. The obtained results proved that the applied solutions have been appropriate.
基金Project(61174068)supported by the National Natural Science Foundation of China
文摘An inverse system method based optimal control strategy was proposed for the shunt hybrid active power filter （SHAPF） to enhance its harmonic elimination performance. Based on the inverse system method, the d-axis and q-axis current dynamics of the SHAPF system were decoupled and linearized into two pseudolinear subsystems. Then, an optimal feedback controUer was designed for the pseudolinear system, and the stability condition of the resulting zero dynamics was presented. Under the control strategy, the current dynamics can asymptotically converge to their reference states and the zero dynamics can be bounded. Simulation results show that the proposed control strategy is robust against load variations and system parameter mismatches, its steady-state performance is better than that of the traditional linear control strategy.
基金supported by the National Natural Science Foundation of China(Grant No.51275557,5142505)the National Science-Technology Support Plan Projects of China(Grant No.2013BAG14B01)
文摘The optimization of the control strategy of a plug-in hybrid electric bus(PHEB) for the repeatedly driven bus route is a key technique to improve the fuel economy. The widely used rule-based(RB) control strategy is lacking in the global optimization property, while the global optimization algorithms have an unacceptable computation complexity for real-time application. Therefore, a novel hybrid dynamic programming-rule based(DPRB) algorithm is brought forward to solve the global energy optimization problem in a real-time controller of PHEB. Firstly, a control grid is built up for a given typical city bus route, according to the station locations and discrete levels of battery state of charge(SOC). Moreover, the decision variables for the energy optimization at each point of the control grid might be deduced from an off-line dynamic programming(DP) with the historical running information of the driving cycle. Meanwhile, the genetic algorithm(GA) is adopted to replace the quantization process of DP permissible control set to reduce the computation burden. Secondly, with the optimized decision variables as control parameters according to the position and battery SOC of a PHEB, a RB control is used as an implementable controller for the energy management. Simulation results demonstrate that the proposed DPRB might distribute electric energy more reasonably throughout the bus route, compared with the optimized RB. The proposed hybrid algorithm might give a practicable solution, which is a tradeoff between the applicability of RB and the global optimization property of DP.
