超短电子脉冲产生的相干谐波

发现了一种产生超辐射谐波的新机制。在这种机制里,谐波脉冲的时间宽度极短;高次谐波与基波的比例比已知的超辐射谐波高得多。     

一维势场中电子对强激光场的非线性散射

数值求解一维势场中电子对强激光场的非线性散射问题,比较了不同形状和深度的势场中电子对不同频率和强度的激光脉冲非线性散射的影响。结果发现：（1）对一定强度和频率的激光脉冲,紧束缚的势场抑制高次谐波的产生;（2）一定势场中,电子对高频场（与低频场强度相同）的散射更易表现出谐波行为,但级次不高。     

超短电子脉冲产生的相干谐波

 发现了一种产生超辐射谐波的新机制。在这种机制里，谐波脉冲的时间宽度极短；高次谐波与基波的比例比已知的超辐射谐波高得多。     

A local two-radii theorem for quasianalytic classes of functions

An exact characteristic of maximal smoothness of nontrivial functions with zero integrals over balls whose radii belong to a given two-element set is obtained..     

The eigenenergies for ~3S excited states of the helium atom with CFPHGLF method

The matrix elements of the correlation function between symmetric potential harmonics were first simplified into the analytical summation of the grand angular momentum. The correlation-function potential-harmonic and generalized Laguerre function method (CFPHGLF) proposed by us recently was then applied to directly solve the Schrodinger equation for n3S(n=2-5) excited states of the helium atom. With only 12 PHs, the convergent eigenenergies of 23S, 33S, 43S and 53S states were 2.17427, 2.06849, 2.03644, 2.02257 Eh, respectively. The errors only were 0.00096, 0.00020, 0.00007, 0.00005 Eh, when compared with the exact Hylleraas variational results respectively.     

Hyperspherical harmonics approach to the trinucleon system with Reid soft core potential: Calculation of geometrical structure coefficients

We present the full set of equations for the solution of the trinucleon problem by the hyperspherical harmonics expansion (HHE) method where nucleons interact via the Reid soft core (RSC) potential. The coupling potential matrix elements are expressed in terms of geometrical structure coefficients (GSC) and potential multipoles (PM). Introduction of GSC greatly simplifies the calculation of the potential matrix and makes the numerical algorithm efficient. A method for calculating all the twelve independent sets of GSC needed, by using the completeness property of the Jacobi polynomials has been presented. A convenient sum rule for each set of GSC has also been derived and precision of the calculated GSC has been checked by the sum rule. Such calculations of GSC are efficient and fast, in view of the complexity of the HHE equations.     

Rotational symmetry of the Hermite projection operators

We calculate an integral formula for the Hermite projection operators. We give some applications of our formula. We also give a short proof of a recent theorem of Thangavelu.

     

Vacuum heating of solid target irradiated by femtosecond laser pulses

The interaction of femtosecond laser pulses with solid targets was studied through experiments and particle-in-cell (PIC) simulations. It is proved that the vacuum heating and the inverse bremsstralung process are the main mechanisms of the laser pulse absorption under such conditions. The distribution of hot electrons and that of X-ray are found to have double-temperature structure, which is confirmed by PIC simulations. While the lower temperature is attributed to the resonant absorption, the higher one, however, is caused by the laser-induced electric field in the target normal direction. The time-integrated spectra ofthe reflected laser pulse shows that the mechanism of electron acceleration is determined by the plasma density profile.     

Unified treatment of complete orthonormal sets of nonrelativistic,quasirelativistic and relativistic sets of spinor wave functions,and Slater spinor orbitals in coordinate,momentum and four-dimensional spaces

Using the properties of tensor spherical harmonics introduced by the author in previous paper (Guseinov, Phys Lett A 372:44, 2007) and complete orthonormal scalar basis sets of nonrelativistic -exponential type orbitals ( -ETO), - momentum space orbitals ( -MSO) and z ^α-hyperspherical harmonics (z ^α-HSH) for particles with spin s = 0 the new analytical relations for the quasirelativistic and relativistic spinor wave functions and Slater spinor orbitals in coordinate, momentum and four-dimensional spaces are derived, where α = 1, 0, −1, −2,.... The 2-component quasirelativistic and 4-component relativistic spinor wave functions obtained are complete without the inclusion of the continuum. The relativistic spinor wave function sets and Slater spinor orbitals are expressed through the corresponding quasirelativistic spinor wave functions and Slater spinor orbitals, respectively. The analytical formulas for overlap integrals over quasirelativistic and relativistic Slater spinor orbitals with the same screening constants in coordinate space are also derived.     

Numerical calculation of overlap and kinetic integrals in prolate spheroidal coordinates

The efficient algorithm calculating the overlap and the kinetic integrals for the numerical atomic orbitals is presented. The described algorithm exploits the properties of the prolate spheroidal coordinates. The overlap and the kinetic integrals in ?³ are reduced to the integrals over the rectangular domain in ?², what substantially reduces the complexity of the problem. We prove that the integrand over the rectangular domain is continuous and does not have any slope singularities. For calculation of the integral over the rectangle any adaptive algorithm can be applied. The exemplary results were obtained by application of the adaptive Gauss quadrature. © 2007 Wiley Periodicals, Inc. Int J Quantum Chem, 2008