In this paper,a new delayed fractional-order model including susceptible migratory birds,infected migratory birds and predators is proposed to discuss the spread of diseases among migratory birds.Fear of predators is ...In this paper,a new delayed fractional-order model including susceptible migratory birds,infected migratory birds and predators is proposed to discuss the spread of diseases among migratory birds.Fear of predators is considered in the model,as fear can reduce the reproduction rate and disease transmission rate among prey.First,some basic mathematical results of the proposed model are discussed.Then,time delay is regarded as a bifurcation parameter,and the delay-induced bifurcation conditions for such an uncontrolled system are established.A novel periodic pulse feedback controller is proposed to suppress the bifurcation phenomenon.It is found that the control scheme can successfully suppress the bifurcation behavior of the system,and the pulse width can be arbitrarily selected on the premise of ensuring the control effect.Compared with the traditional time-delay feedback controller,the control scheme proposed in this paper has more advantages in practical application,which not only embodies the advantages of low control cost and easy operation but also caters to the periodic changes of the environment.The proposed control scheme,in particular,remains effective even after the system has been disrupted by a constant.Numerical simulation verifies the correctness of the theoretical results.展开更多
W<sub>HEN</sub> a dissociative system is subjected to an intense laser pulse, it will be photo-ionized. In the photo-ionization process, the dissociative system will develop a time-dependent dipole moment ...W<sub>HEN</sub> a dissociative system is subjected to an intense laser pulse, it will be photo-ionized. In the photo-ionization process, the dissociative system will develop a time-dependent dipole moment and emit an odd harmonic of the incident laser frequency. In the past ten years, optical harmomc generation has attracted much attention. This is because high optical harmonics will undoubtedly lead to the development of bright, short-pulse and versatile sources of coherent radiation in the vacuum ultraviolet （UV） and X-ray ranges. In addition, its ultrashort characteristic will be important for investigating many ultrafast phenomena. But people展开更多
基金supported by Liaoning Provincial Department of Education Scientific Research Fund Project(lnjc202018).
文摘In this paper,a new delayed fractional-order model including susceptible migratory birds,infected migratory birds and predators is proposed to discuss the spread of diseases among migratory birds.Fear of predators is considered in the model,as fear can reduce the reproduction rate and disease transmission rate among prey.First,some basic mathematical results of the proposed model are discussed.Then,time delay is regarded as a bifurcation parameter,and the delay-induced bifurcation conditions for such an uncontrolled system are established.A novel periodic pulse feedback controller is proposed to suppress the bifurcation phenomenon.It is found that the control scheme can successfully suppress the bifurcation behavior of the system,and the pulse width can be arbitrarily selected on the premise of ensuring the control effect.Compared with the traditional time-delay feedback controller,the control scheme proposed in this paper has more advantages in practical application,which not only embodies the advantages of low control cost and easy operation but also caters to the periodic changes of the environment.The proposed control scheme,in particular,remains effective even after the system has been disrupted by a constant.Numerical simulation verifies the correctness of the theoretical results.
文摘W<sub>HEN</sub> a dissociative system is subjected to an intense laser pulse, it will be photo-ionized. In the photo-ionization process, the dissociative system will develop a time-dependent dipole moment and emit an odd harmonic of the incident laser frequency. In the past ten years, optical harmomc generation has attracted much attention. This is because high optical harmonics will undoubtedly lead to the development of bright, short-pulse and versatile sources of coherent radiation in the vacuum ultraviolet （UV） and X-ray ranges. In addition, its ultrashort characteristic will be important for investigating many ultrafast phenomena. But people
