4f结构间距失调对达曼类滤波器输出脉冲特性的影响

 研究了4f结构的飞秒脉冲时空变换整形装置在各元件间距不等的情况下对脉冲输出特性的影响，理论分析了间距失调效应对等间距和不等间距达曼光栅滤波器的脉冲输出特性的影响。结果表明4f结构间距失调后无论是能量还是平均度都不如等间距高，中心脉冲能量变小，其它级次脉冲生出更多旁瓣；失调量越小，输出的脉冲质量越高，对于f为12 cm的装置，当失调量小于1 cm时，对输出脉冲影响较小。     

类铍离子磁四极M2 2s2 1S0—2s2p3P2 (Z=10—103)禁戒跃迁

利用全相对论多组态Dirac-Fock方法系统地计算了高离化类铍离子的磁四极M2 2s²¹S₀—2s2p³P₂ (Z=10—103)自旋禁戒跃迁的能级间隔、跃迁概率和振子强度，计算中考虑了重要核的有限体积效应，Breit修正和QED修正，所得结果和最近的实验数据以及理论值进行了比较，结果表明：高原子序数的高电荷离子(Z≥70)磁四极M2自旋禁戒跃迁几乎可以和中性原子的光学允许跃迁相比拟，不仅在天体等离子体中，在ICF和MCF高温激光等离子体中，磁四极自旋禁戒跃迁和其他自旋禁戒跃迁（磁偶极、电四极）一样不容忽视，在双电子复合、不透明度、自由程等理论计算中应该考虑其影响. 关键词： 磁四极M2 能级间隔 跃迁概率 振子强度     

芶清泉教授从事科教工作六十五周年的主要成就与贡献

芶清泉教授于1917年4月14日出生于四川省邛崃县.1942年毕业于国立中央大学物理系.大学毕业后,先后在国立中央大学、西南联大、北京大学、华西大学、南京大学、四川大学、东北工学院、吉林大学和成都科技大学从事教学与科研工作,已达六十五周年之久.……     

外电场作用下SiO电子结构特性研究

在得到SiO分子基态稳定构型的基础上，选用B3P86/6-311++g(d，p)方法优化得到了不同外电场(-0.03—0.03a.u.)下SiO分子基态的稳定电子结构，研究了外电场对SiO分子基态键长、能量、电荷分布、能级分布，能隙及红外光谱的影响规律.结果表明，分子结构与电场呈现强烈的依赖关系，且对电场的方向依赖呈现出不对称性.同时在正向外电场逐渐增大的过程中，SiO分子能隙始终处于减小趋势，占据轨道的电子易于激发至空轨道，因而为研究材料的电致发光机理奠定了一定的理论基础.     

通过以太无源光网的射频电视传送技术

论述了1550 nm射频电视(CATV)通道与1490 nm数据通道的相互干扰问题。针对1490 nm光波通过光纤中受激拉曼效应对1550 nm光波的非线性串扰和1550 nm光波通过粗波分复用(CWDM)分波器对1490 nm光波的线性串扰提出了理论计算公式,进行了定量分析和计算。结果表明,数据非线性串扰可使射频电视系统低频端的载噪比下跌9 dB;而在常规融锥型粗波分复用分波器情况下,射频电视线性串扰可使数据光接收机的光功率代价达到2.5dB。最后指出了克服串扰的方法,如以太空闲字符扰码和高隔离度粗波分复用等。     

Al2O3X(X=H,D,T)的电子振动近似理论方法研究

用密度泛函理论(DFT)方法在6-311 G(d,p)水平上对Al2O3X(X=H,D,T)分子较低能量的几何构型进行了优化.计算结果表明该分子有两个可能基态,即Al2O3X(X=H,D,T)(2A′)Cs和Al2O3X(X=H,D,T)(2B2)C2v.全电子计算了氢同位素分子及Al2O3X(X=H,D,T)的能量E、定容热容CV和熵S.应用电子振动近似理论,即用单个分子Al2O3X(X=H,D,T)中的电子和振动能量和熵近似代表它们处于固态时的能量和熵,计算得到固体Al2O3的氢化热力学函数ΔH0,ΔS0,ΔG0以及平衡压力与温度的关系.当Al2O3吸附氢(氘,氚)形成C2v对称性气态Al2O3X(X=H,D,T)对应的固体时,氢气可以排代氘气,氘气可以排代氚气.这种排代效应非常不明显;形成Cs对称性气态Al2O3X(X=H,D,T)对应的固体时,反应的氢氘氚排代效应的顺序为氚排代氘,氘排代氢,与钛等的氢氘氚排代效应的顺序相反.总体而言,这种排代效应都非常弱.随着温度的增加,这一系列反应的氢氘氚排代效应趋于消失.     

Ultrahigh Harmonic Generation from an Atom with Superposition of Ground State and Highly Excited States

We investigate the high-order harmonic generation from an atom prepared in a superposition of ground state and highly excited state. When the atom is irradiated by an ultrashort pulse, the cutoff position of the plateau in the harmonic spectrum is largely extended compared with the case that the atom is initially in the ground state. The physics of the extension of the high-order harmonic plateau can be interpreted by the spatial structure of the atomic initial wave packet. We can optimize the generation of high-order harmonics by substituting the excited state for a particular coherent superposition of some highly excited states to form a spatially localized excited wave packet.     

Potential Energy Surfaces of Nitrogen Dioxide for the Ground State

The potential energy function of nitrogen dioxide with the C2v symmetry in the ground state is represented using the simplified Sorbie-Murrell many-body expansion function in terms of the symmetry of NO2. Using the potential energy function, some potential energy surfaces of NO2（C2v, X^-^2A1）, such as the bond stretching contour plot for a fixed equilibrium geometry angle θ and contour for O moving around N-O （R1）, in which R1 is fixed at the equilibrium bond length, are depicted. The potential energy surfaces are analysed. Moreover, the equilibrium parameters for NO2 with the C2v, Cs and Dsn symmetries, such as equilibrium geometry structures and energies, are calculated by the ab initio （CBS-Q） method.     

Analytical potential energy function for the electronic states 2^∏1/2 and 2^∏3/2 of O^x2 （x=＋1, -1）

The splitting of potential energy levels for ground state X^2∏g of O^x2 （x = ＋1,-1） under spin-orbit coupling （SOC） has been calculated by using the spin-orbit （SO） multi-configuration quasi-degenerate perturbation theory （SO-MCQDPT）. Their Murrell-Sorbie （M S） potential functions are gained, and then the spectroscopic constants for electronic states 2^∏1/2 and 2^∏3/2 are derived from the M S function. The vertical excitation energies for O^x2 （x = ＋1,-1） are v[O2＋1^（2∏3/2→X^2∏1/2）] =195.652cm^-1, and v[O2^-1（2^∏1/2 →X^2∏3/2）] =182.568cm^-1, respectively. All the spectroscopic data for electronic states 2^∏1/2 and 2^∏3/2 are given for the first time.     

Spin polarization effect of Ni2 molecule

The density functional theory （DFT） method （b3p86） of Gaussian 03 is used to optimize the structure of the Ni2 molecule. The result shows that the ground state for the Ni2 molecule is a 5-multiple state, symbolizing a spin polarization effect existing in the Ni2 molecule, a transition metal molecule, but no spin pollution is found because the wavefunction of the ground state does not mingle with wavefunctions of higher-energy states. So the ground state for Ni2 molecule, which is a 5-multiple state, is indicative of spin polarization effect of the Ni2 molecule, that is, there exist 4 parallel spin electrons in Ni2 molecule. The number of non-conjugated electrons is greatest. These electrons occupy different spatial orbitals so that the energy of the Ni2 molecule is minimized. It can be concluded that the effect of parallel spin in the Ni2 molecule is larger than that of the conjugated molecule, which is obviously related to the effect of electron d delocalization. In addition, the Murrell-Sorbie potential functions with the parameters of the ground state and other states of the Ni2 molecule are derived. The dissociation energy De for the ground state of the Ni2 molecule is 1.835 eV, equilibrium bond length Re is 0.2243 nm, vibration frequency we is 262.35 cm^-1. Its force constants f2, f3 and f4 are 1.1901 aJ.nm^-2, -5.8723 aJ.nm^-3, and 21.2505 aJ.nm^-4 respectively. The other spectroscopic data for the ground state of the Ni2 molecule ωeχe, Be and αe are 1.6315cm 2, 0.1141 cm^-1, and 8.0145× 10^-4 cm^-1 respectively.