Based upon the Hellinger-Reissner (H-R) mixed variational principle for three-dimensional elastic bodies, the modified H-R mixed variational theorem for magnetoelectroelastic bodies was established. The state-vector e...Based upon the Hellinger-Reissner (H-R) mixed variational principle for three-dimensional elastic bodies, the modified H-R mixed variational theorem for magnetoelectroelastic bodies was established. The state-vector equation of magnetoelectroelastic plates was derived from the proposed theorem by performing the variational operations. To lay a theoretical basis of the semi-analytical solution applied with the magnetoelectroelastic plates, the state-vector equation for the discrete element in plane was proposed through the use of the proposed principle. Finally, it is pointed out that the modified H-R mixed variational principle for pure elastic, single piezoelectric or single piezomagnetic bodies are the special cases of the present variational theorem.展开更多
The structure of the state-vector space of identical bosons in noncommutative spaces is investigated. To maintain Bose-Einstein statistics the commutation relations of phase space variables should simultaneously inclu...The structure of the state-vector space of identical bosons in noncommutative spaces is investigated. To maintain Bose-Einstein statistics the commutation relations of phase space variables should simultaneously include coordinate-coordinate non-commutativity and momentum-momentum non-commutativity, which leads to a kind of deformed Heisenberg-Weyl algebra. Although there is no ordinary number representation in this state-vector space, several set of orthogonal and complete state-vectors can be derived which are common eigenvectors of corresponding pairs of commuting Hermitian operators. As a simple application of this state-vector space, an explicit form of two-dimensional canonical coherent state is constructed and its properties are discussed.展开更多
在锂离子电池正常使用过程中,受内部化学反应和外部环境等因素影响,锂离子电池容量会在短期内出现再生现象。针对未考虑锂离子电池容量再生现象导致电池健康状态SOH(state-of-health)估计不精确等问题,提出基于层数的最优变分模态分解策...在锂离子电池正常使用过程中,受内部化学反应和外部环境等因素影响,锂离子电池容量会在短期内出现再生现象。针对未考虑锂离子电池容量再生现象导致电池健康状态SOH(state-of-health)估计不精确等问题,提出基于层数的最优变分模态分解策略OVMD(optimal variational mode decomposition),聚类容量反映整体老化趋势的低频平稳序列和反映局部容量再生的高频非平稳序列。考虑容量高频和低频分量,引入加权向量平均INFO(weighted mean of vectors)方法改进支持向量回归SVR(support vector regression),建立锂离子电池短期SOH估计模型。选取NASA电池老化数据集,设计基于反向传播BP(back propagation)神经网络、SVR、INFO-SVR、OVMD-INFO-SVR的短期锂离子电池SOH估计实验对比方案。结果表明,在减少容量训练集的情况下,基于高频和低频分量的OVMD-INFO-SVR模型在锂离子电池短期SOH的估计上具有更高的准确性。展开更多
基金Project supported by the National Natural Science Foundation of China (No. 10072038)the Special Fund for PhD Program of Education Ministry of China (No. 2000005616)
文摘Based upon the Hellinger-Reissner (H-R) mixed variational principle for three-dimensional elastic bodies, the modified H-R mixed variational theorem for magnetoelectroelastic bodies was established. The state-vector equation of magnetoelectroelastic plates was derived from the proposed theorem by performing the variational operations. To lay a theoretical basis of the semi-analytical solution applied with the magnetoelectroelastic plates, the state-vector equation for the discrete element in plane was proposed through the use of the proposed principle. Finally, it is pointed out that the modified H-R mixed variational principle for pure elastic, single piezoelectric or single piezomagnetic bodies are the special cases of the present variational theorem.
基金The project Supported by National Natural Science Foundation of China under Grant Nos. 10375056 and 90203002
文摘The structure of the state-vector space of identical bosons in noncommutative spaces is investigated. To maintain Bose-Einstein statistics the commutation relations of phase space variables should simultaneously include coordinate-coordinate non-commutativity and momentum-momentum non-commutativity, which leads to a kind of deformed Heisenberg-Weyl algebra. Although there is no ordinary number representation in this state-vector space, several set of orthogonal and complete state-vectors can be derived which are common eigenvectors of corresponding pairs of commuting Hermitian operators. As a simple application of this state-vector space, an explicit form of two-dimensional canonical coherent state is constructed and its properties are discussed.
文摘在锂离子电池正常使用过程中,受内部化学反应和外部环境等因素影响,锂离子电池容量会在短期内出现再生现象。针对未考虑锂离子电池容量再生现象导致电池健康状态SOH(state-of-health)估计不精确等问题,提出基于层数的最优变分模态分解策略OVMD(optimal variational mode decomposition),聚类容量反映整体老化趋势的低频平稳序列和反映局部容量再生的高频非平稳序列。考虑容量高频和低频分量,引入加权向量平均INFO(weighted mean of vectors)方法改进支持向量回归SVR(support vector regression),建立锂离子电池短期SOH估计模型。选取NASA电池老化数据集,设计基于反向传播BP(back propagation)神经网络、SVR、INFO-SVR、OVMD-INFO-SVR的短期锂离子电池SOH估计实验对比方案。结果表明,在减少容量训练集的情况下,基于高频和低频分量的OVMD-INFO-SVR模型在锂离子电池短期SOH的估计上具有更高的准确性。
