The local structure distortion, the spin Hamiltonian （SH） parameters, and the electric fine structure of the ground state for Mn^2＋ （3d^5） ion in ZnO crystals are systematically investigated, where spin-spin （SS...The local structure distortion, the spin Hamiltonian （SH） parameters, and the electric fine structure of the ground state for Mn^2＋ （3d^5） ion in ZnO crystals are systematically investigated, where spin-spin （SS）, spin-other-orbit （SOO） and orbit-orbit （OO） magnetic interactions, besides the well-known spin-orbit （SO） coupling, are taken into account for the first time, by using the complete diagonalization method. The theoretical results of the second-order zerofield splitting （ZFS） parameter D, the fourth-order ZFS parameter （a-F）, the Zeeman g-factors： g// and g⊥, and the energy differences of the ground state： δ1 and δ2 for Mn^2＋ in Mn^2＋： ZnO are in good agreement with experimental measurements when the three O^2- ions below the Mn^2＋ ion rotate by 1.085° away from the [111]-axis. Hence, the local structure distortion effect plays an important role in explaining the spectroscopic properties of Mn^2＋ ions in Mn^2＋： ZnO crystals. It is found for Mn^2＋ ions in Mn^2＋： ZnO crystals that although the SO mechanism is the most important one, the contributions to the SH parameters, made by other four mechanisms, i.e. SS, SOO, OO, and SO-SS-SOO-OO mechanisms, are significant and should not be omitted, especially for calculating ZFS parameter D.展开更多
This paper investigates a parameterization method of adaptive H∞ controllers for dissipative Hamiltonian systems with disturbances and unknown parameters.The family of adaptive H∞ controllers with full information i...This paper investigates a parameterization method of adaptive H∞ controllers for dissipative Hamiltonian systems with disturbances and unknown parameters.The family of adaptive H∞ controllers with full information is obtained by interconnecting an adaptive H∞ controller with a generalized zero-energy-gradient （ZEG） detectable,free generalized Hamiltonian system.The present parameterization method avoids solving Hamilton-Jacobi-Issacs equations and thus the controllers obtained are easier in operation as compared to some existing ones.Simulations show the effectiveness and feasibility of the adaptive control strategy proposed in this paper.展开更多
基金supported by the Science and Technology Foundation of Shaanxi Province,China (Grant No 2006K04-G29)the National Defense Foundation of China (Grant No EP060302)the Key Research Foundation of Baoji University of Arts and Sciences,China (Grant No ZK0842)
文摘The local structure distortion, the spin Hamiltonian （SH） parameters, and the electric fine structure of the ground state for Mn^2＋ （3d^5） ion in ZnO crystals are systematically investigated, where spin-spin （SS）, spin-other-orbit （SOO） and orbit-orbit （OO） magnetic interactions, besides the well-known spin-orbit （SO） coupling, are taken into account for the first time, by using the complete diagonalization method. The theoretical results of the second-order zerofield splitting （ZFS） parameter D, the fourth-order ZFS parameter （a-F）, the Zeeman g-factors： g// and g⊥, and the energy differences of the ground state： δ1 and δ2 for Mn^2＋ in Mn^2＋： ZnO are in good agreement with experimental measurements when the three O^2- ions below the Mn^2＋ ion rotate by 1.085° away from the [111]-axis. Hence, the local structure distortion effect plays an important role in explaining the spectroscopic properties of Mn^2＋ ions in Mn^2＋： ZnO crystals. It is found for Mn^2＋ ions in Mn^2＋： ZnO crystals that although the SO mechanism is the most important one, the contributions to the SH parameters, made by other four mechanisms, i.e. SS, SOO, OO, and SO-SS-SOO-OO mechanisms, are significant and should not be omitted, especially for calculating ZFS parameter D.
基金supported by National Natural Science Foundation of China (No. 61074189)
文摘This paper investigates a parameterization method of adaptive H∞ controllers for dissipative Hamiltonian systems with disturbances and unknown parameters.The family of adaptive H∞ controllers with full information is obtained by interconnecting an adaptive H∞ controller with a generalized zero-energy-gradient （ZEG） detectable,free generalized Hamiltonian system.The present parameterization method avoids solving Hamilton-Jacobi-Issacs equations and thus the controllers obtained are easier in operation as compared to some existing ones.Simulations show the effectiveness and feasibility of the adaptive control strategy proposed in this paper.
