基于子阵策略和区域分解矩量法的电磁散射分析方法

针对现代雷达工程中,无法高效计算电磁新材料及频率选择表面等有限大周期结构的问题,提出了一种子阵策略与区域分解矩量法相结合的电磁散射分析方法。通过选取一个小型周期结构(小阵),将整个小阵目标分成若干个互不相连的子区域,利用区域分解矩量法求得小阵上每个子区域表面的感应电流,来等效整个周期结构的表面电流,从而高效分析有限大周期结构的电磁散射特性。通过2个数值算例表明,该方法不仅大大降低了内存消耗,且与矩量法及区域分解矩量法相比,该方法在不失精度的情况下分别使圆金属和十字金属阵列的计算时间减少了88.2%和90.6%,证明了该方法的正确性和高效性。

大孔径高频阵超高指向性测量的子阵分解方法

猎雷声呐这类小目标声呐的高频阵,波束极窄,通常在0.1°～0.2°范围,远场距离很远,约在三四百米以上.在常规球面波声场条件下测量指向性难以实施,近距离测量又不符合远场条件.本文将阵分成若干子阵,子阵的波束宽,远场距离近,可以先在近距离测量各子阵的复数指向性,然后推算总阵的指向性.测量是在邻近区以内的准球面波声场进行的,实验结果很好地验证了所提出的原理和方法.

Model Potential Calculations of Oscillator Strength Spectra of Rydberg Li Atoms in External Fields

By combining the B-spline basis set with model potential (B-spline + MP),we present oscillator strengthspectra of Rydberg Li atoms in external fields.The photoabsorption spectra are analyzed.Over the narrow energyranges considered in this paper,the structure of the spectra can be independent of the initial state chosen for a givenatom.Our results are in good agreement with previous high-precision experimental data and theoretical calculations,where the R-matrix approach together with multichannel quantum defect theory (R-matrix+MQDT) was used.It issuggested that the present methods can be applied to deal with the oscillator strength spectra of Rydberg atoms incrossed electric and magnetic fields.

Analytic Expression of Arbitrary Matrix Elements for Boson Exponential Quadratic Polynomial Operators

Making use of the transformation relation among usual, normal, and antinormal ordering for the multimode boson exponential quadratic polynomial operators （BEQPO＇s）I we present the analytic expression of arbitrary matrix elements for BEQPO＇s. As a preliminary application, we obtain the exact expressions of partition function about the boson quadratic polynomial system, matrix elements in particle-number, coordinate, and momentum representation, and P representation for the BEQPO＇s.

Darboux Transformations and N-soliton Solutions of Two (2+1)-Dimensional Nonlinear Equations

Two Darboux transformations of the(2+1)-dimensional Caudrey–Dodd–Gibbon–Kotera–Sawaka(CDGKS)equation and(2+1)-dimensional modified Korteweg-de Vries(mKdV) equation are constructed through the Darboux matrix method, respectively. N-soliton solutions of these two equations are presented by applying the Darboux transformations N times. The right-going bright single-soliton solution and interactions of two and three-soliton overtaking collisions of the(2+1)-dimensional CDGKS equation are studied. By choosing different seed solutions, the right-going bright and left-going dark single-soliton solutions, the interactions of two and three-soliton overtaking collisions, and kink soliton solutions of the(2+1)-dimensional mKdV equation are investigated. The results can be used to illustrate the interactions of water waves in shallow water.

Polaron Effect of a Two Electron Parabolic Quantum Dot

Polaron induced double electron in a quantum dot is investigated using the exact diagonalization techniques and the compact density-matrix approach. The dependence of nonlinear optical processes on the incident photon energies and the polaronic effect are brought out. The linear, third order non-linear optical absorption coefficients and the refractive index changes of singlet and triplet states as a function of photon energy are obtained with and without the inclusion of polaronic effect. It is found that the geometrical confinement and the effect of polaron have great influence on the optical properties of dots.

Quasi Three-Body Decay of D Meson

The aim of this work is to provide a phenomenological analysis of the contribution of D^0 meson to K*(892)~0π^+π^-(K*(892)~0-→π^+K^-), K^-π^+ω(ω-→π^+π^-π~0) and K^-π^+?(?(1020)-→ K^+K^-) quasi-three-body decays. The analysis of mentioned multi-body decays is such as to factorize into the three-body decay and several channels observed. Hadronic three-body decays receive both resonant and non-resonant contribution. Based on the factorization method, there are tree and emission annihilation diagrams for these decay modes. In the case of D^0 to vector pseudoscalar states appeared in factored terms, the matrix elements of the vector and axial vector currents between the D^0 and PV mesons can be computed by using D^(*+)pole. Considering the non-resonant and resonant amplitude in our computation,the theoretical values of the branching ratio are(9.78 ± 0.46) × 10^(-3),(2.74 ± 0.17) × 10^(-2), and(3.53 ± 0.23) × 10^(-5), while the experimental results of them are(9.9 ±2.3) × 10^(-3),(2.7 ± 0.5) × 10^(-2), and(4 ± 1.7) × 10^(-5) respectively. Comparing computational analysis values with experimental values show that our results are in approximately agreement with them.

Direct visualization of the charge transfer in conjugated polymers

Ion-induced charge-transfer states in conjugated polyelectrolytes were experimentally investigated by Justin M.Hodgkiss and his co-workers [J Am Chem Soc,2009,131(25):8913].In this work,charged and neutral conjugated polyelectrolytes were further studied with quantum chemistry methods.The calculation result shows that the absorption spectra are roughly in visible and ultraviolet light regions,and the two absorption peaks are located in the wavelength span 300-400 nm for charged polyelectrolytes.However,in neutral conjugated polyelectrolytes,the peaks of the absorption spectra showed a blue shift compared with those of the charged polyelectrolytes.Charge transfer (CT) properties of the studied compounds were also investigated with both the three-dimensional real-space analysis method of transition and charge difference densities,and the two-dimensional real-space analysis method of transition density matrices based on the simulated absorption spectra.The calculation results revealed the charge transfer in conjugated polyelectrolytes on the excitation states.