Response of the wave packet of a one-dimensional Coulomb atom to an intense laser field is calculated using the symmetrized split operator fast Fourier method. The high-order harmonic generation （HHG） of the initial...Response of the wave packet of a one-dimensional Coulomb atom to an intense laser field is calculated using the symmetrized split operator fast Fourier method. The high-order harmonic generation （HHG） of the initial state separately being the ground and excited states is presented. When the hardness parameter a in the soft Coulomb potential V（x） =-1√x^2＋α is chosen to be small enough, the so-called hard Coulomb potential V（x）=1/｜x｜ can be obtained. It is well known that the hard one-dimensional Coulomb atom has an unstable ground state with an energy eigenvalue of - 0.5 and it has no states corresponding to physical states in the true atoms, and has the first and second excited states being degenerate. The parity effects on the HHG can be seen from the first and second excited states of the hard one-dimensional Coulomb atom. The HHG spectra of the excited states from both the soft and hard Coulomb atom models are shown to have more complex structures and to be much stronger than the corresponding HHG spectrum of the ground state of the soft Coulomb model with a = 2 in the same laser field. Laser-induced non-resonant one-photon emission is also observed.展开更多
针对近场信源定位中自由度小、准确性低等问题,提出一种基于四阶累量矩阵的定位算法。首先构造等效导向矢量包含波达方向(Direction of arrival,DOA)和距离信息的高维虚拟协方差矩阵,在角度估计中,提出基于矩阵秩亏来搜索最小奇异值倒...针对近场信源定位中自由度小、准确性低等问题,提出一种基于四阶累量矩阵的定位算法。首先构造等效导向矢量包含波达方向(Direction of arrival,DOA)和距离信息的高维虚拟协方差矩阵,在角度估计中,提出基于矩阵秩亏来搜索最小奇异值倒数的一维搜索方法,降低了计算量,在增大自由度的同时利用高斯噪声高阶累量为零的特性提高了低信噪比下的性能;在不进行额外计算的前提下,直接利用角度估计中进行奇异值分解时得到的奇异向量所包含的距离信息,通过最小二乘法得到距离。仿真结果表明,相比于已有算法,该方法可以仅在一个高阶累量矩阵中通过一维搜索估计角度和距离,在降低复杂度的同时提高了准确性,并且提出方法的自由度是降维多重信号分类方法的2倍。展开更多
针对单传感器采集的电场强度值易发生畸变影响电压等级辨识准确率的问题,提出基于多传感器协同融合识别电压等级,对传感器进行非正交、分层布局,建立空间矢量电场降维重构模型,对多传感器采集数据进行协同融合计算最强电场强度值。对最...针对单传感器采集的电场强度值易发生畸变影响电压等级辨识准确率的问题,提出基于多传感器协同融合识别电压等级,对传感器进行非正交、分层布局,建立空间矢量电场降维重构模型,对多传感器采集数据进行协同融合计算最强电场强度值。对最强电场强度值进行二阶拟合,由二阶拟合参数识别电压等级。搭建实验平台,通过实验平台控制场源电压等级分别为10,35,110 k V,将采集数据装置靠近场源采集数据,根据处理后的拟合参数图形显示,可清晰地看到不同电压等级聚集在三维坐标系中不同位置。展开更多
基金Project supported by the National Natural Science Foundation of China （Grant No 10474138） and the National High-Tech Inertial Confinement Fusion Committee in China.
文摘Response of the wave packet of a one-dimensional Coulomb atom to an intense laser field is calculated using the symmetrized split operator fast Fourier method. The high-order harmonic generation （HHG） of the initial state separately being the ground and excited states is presented. When the hardness parameter a in the soft Coulomb potential V（x） =-1√x^2＋α is chosen to be small enough, the so-called hard Coulomb potential V（x）=1/｜x｜ can be obtained. It is well known that the hard one-dimensional Coulomb atom has an unstable ground state with an energy eigenvalue of - 0.5 and it has no states corresponding to physical states in the true atoms, and has the first and second excited states being degenerate. The parity effects on the HHG can be seen from the first and second excited states of the hard one-dimensional Coulomb atom. The HHG spectra of the excited states from both the soft and hard Coulomb atom models are shown to have more complex structures and to be much stronger than the corresponding HHG spectrum of the ground state of the soft Coulomb model with a = 2 in the same laser field. Laser-induced non-resonant one-photon emission is also observed.
文摘针对近场信源定位中自由度小、准确性低等问题,提出一种基于四阶累量矩阵的定位算法。首先构造等效导向矢量包含波达方向(Direction of arrival,DOA)和距离信息的高维虚拟协方差矩阵,在角度估计中,提出基于矩阵秩亏来搜索最小奇异值倒数的一维搜索方法,降低了计算量,在增大自由度的同时利用高斯噪声高阶累量为零的特性提高了低信噪比下的性能;在不进行额外计算的前提下,直接利用角度估计中进行奇异值分解时得到的奇异向量所包含的距离信息,通过最小二乘法得到距离。仿真结果表明,相比于已有算法,该方法可以仅在一个高阶累量矩阵中通过一维搜索估计角度和距离,在降低复杂度的同时提高了准确性,并且提出方法的自由度是降维多重信号分类方法的2倍。
文摘针对单传感器采集的电场强度值易发生畸变影响电压等级辨识准确率的问题,提出基于多传感器协同融合识别电压等级,对传感器进行非正交、分层布局,建立空间矢量电场降维重构模型,对多传感器采集数据进行协同融合计算最强电场强度值。对最强电场强度值进行二阶拟合,由二阶拟合参数识别电压等级。搭建实验平台,通过实验平台控制场源电压等级分别为10,35,110 k V,将采集数据装置靠近场源采集数据,根据处理后的拟合参数图形显示,可清晰地看到不同电压等级聚集在三维坐标系中不同位置。
