The Kapchinsky Vladimirsky(K-V)beam through a hackle periodic-focusing magnetic field is studiedusing the particle-core model.The beam halo-chaos is found,and an idea of fraction power-law function controller ispropos...The Kapchinsky Vladimirsky(K-V)beam through a hackle periodic-focusing magnetic field is studiedusing the particle-core model.The beam halo-chaos is found,and an idea of fraction power-law function controller isproposed based on the mechanism of halo formation and the strategy of controlling halo-chaos.The method is appliedto the multi-particle simulation to control the halo.The numerical results show that the halo-chaos and its regenerationcan be eliminated effectively by using the fraction power-law function control method.At the same time,the radialparticle density is uniform at the beam's center as long as the control method and appropriate parameter are chosen.展开更多
It has been widely accepted that spherical per- iodicity generally dominates liquid and amorphous structure formation, where atoms tend to gather near spherically peri- odic shells according to Friedel oscillation. He...It has been widely accepted that spherical per- iodicity generally dominates liquid and amorphous structure formation, where atoms tend to gather near spherically peri- odic shells according to Friedel oscillation. Here it is revealed that the same order is just hidden in the atomic global packing modes of the crystalline phases relevant to bulk metallic glasses. Among the multiple nearest-neighbor dusters devel- oped from all the non-equivalent atomic sites in a given phase, there always exists a principal duster, centered by which the spherical periodicity, both topologically and chemically, is the most distinct. Then the principal dusters plus specific glue atoms just constitute the cluster-plus-glue-atom structural units shared by both metallic glasses and the corresponding crystalline phases. It is further pointed out that the spherical periodicity order represents the common structural homology of crystalline and amorphous states in the medium-range through scrutinizing all binary bulk-glass-relevant phases in Cu-（Zr, Hf）, Ni-（Nb, Ta）, Al-Ca, and Pd-Si systems.展开更多
This paper investigates the theoretical aspects for an optimal harvesting problem of a nonlinear size-structured population model in a periodic environment. We establish the well-posedness of the state system by means...This paper investigates the theoretical aspects for an optimal harvesting problem of a nonlinear size-structured population model in a periodic environment. We establish the well-posedness of the state system by means of frozen coefficients and fixed point reasoning. The existence of a unique optimal policy is proved via Ekeland＇s variational principle, and the first-order optimality conditions are derived by a suitable normM cone and a dual system. The results obtained would be beneficial for exploration of renewable展开更多
基金National Natural Science Foundation of China under Crant No.10247005the Natural Science Foundation of the Anhui Higher Education Institutions of China under Grant No.KJ2007B187the Scientific Research Foundation of China University Of Mining and Technology for the Young under Grant No.OK060119
文摘The Kapchinsky Vladimirsky(K-V)beam through a hackle periodic-focusing magnetic field is studiedusing the particle-core model.The beam halo-chaos is found,and an idea of fraction power-law function controller isproposed based on the mechanism of halo formation and the strategy of controlling halo-chaos.The method is appliedto the multi-particle simulation to control the halo.The numerical results show that the halo-chaos and its regenerationcan be eliminated effectively by using the fraction power-law function control method.At the same time,the radialparticle density is uniform at the beam's center as long as the control method and appropriate parameter are chosen.
基金supported by the Science Challenge Program (JCKY2016212A504)the National Natural Science Foundation of China(11674045)
文摘It has been widely accepted that spherical per- iodicity generally dominates liquid and amorphous structure formation, where atoms tend to gather near spherically peri- odic shells according to Friedel oscillation. Here it is revealed that the same order is just hidden in the atomic global packing modes of the crystalline phases relevant to bulk metallic glasses. Among the multiple nearest-neighbor dusters devel- oped from all the non-equivalent atomic sites in a given phase, there always exists a principal duster, centered by which the spherical periodicity, both topologically and chemically, is the most distinct. Then the principal dusters plus specific glue atoms just constitute the cluster-plus-glue-atom structural units shared by both metallic glasses and the corresponding crystalline phases. It is further pointed out that the spherical periodicity order represents the common structural homology of crystalline and amorphous states in the medium-range through scrutinizing all binary bulk-glass-relevant phases in Cu-（Zr, Hf）, Ni-（Nb, Ta）, Al-Ca, and Pd-Si systems.
文摘This paper investigates the theoretical aspects for an optimal harvesting problem of a nonlinear size-structured population model in a periodic environment. We establish the well-posedness of the state system by means of frozen coefficients and fixed point reasoning. The existence of a unique optimal policy is proved via Ekeland＇s variational principle, and the first-order optimality conditions are derived by a suitable normM cone and a dual system. The results obtained would be beneficial for exploration of renewable
