适合于应用实验的X射线激光探针

X射线激光实验研究的主要目的是进行相应的应用研究。由于具有波长短、脉冲短、亮度高、相干性好的优点，因此在很多领域有潜在的应用前景。在所有的应用中，利用X射线激光作为探针来诊断等离子体或其他介质材料方面的应用是最普遍的。一般来说，激光探针穿越等离子体或介质后，光束的强度、前进方向、光程都会发生变化。分别检测这些变化，就可以获得等离子体的电子密度或介质折射率的相关信息。这就需要对作为探针的X射线激光的输出特性有深入的了解，并且选择更合适的条件进行优化。采用场图测量的方法，即直接测量X射线激光的输出光束在某一位置处的截面光强分布，能够很好地提供关于X射线激光输出光束的全面的信息，对应用研究具有很好的参考和指导作用。     

Isoscalar Giant Resonances of ^120Sn in the Quasiparticle Relativistic Random Phase Approximation

The quasiparticle relativistic random phase approximationmean field ground state in the response function formalism(QRRPA) is formulated based on the relativistic The pairing correlations are taken into accountin the Bardeen-Cooper-Schrieffer approximation with a constant pairing gap. The numerical calculations are performed in the case of various isoscalar giant resonances of nucleus ^120Sn with parameter set NL3. The calculated results show that the QRRPA approach could satisfactorily reproduce the experimental data of the energies of low-lying states.     

Damage and fracture evaluation of granular composite materials by digital image correlation method

This paper presents the applications of digital image correlation technique to the mesoscopic damage and fracture study of some granular based composite materials including steelfiber reinforced concrete, sandstone and crystal-polymer composite. The deformation fields of the composite materials resulted from stress localization were obtained by the correlation computation of the surface images with loading steps and thus the related damage prediction and fracture parameters were evaluated. The correlation searching could be performed either directly based on the gray levels of the digital images or from the wavelet transform (WT) coefficients of the transform spectrum. The latter was developed by the authors and showed higher resolution and sensitivity to the singularity detection. Because the displacement components came from the rough surfaces of the composite materials without any coats of gratings or fringes of optical interferometry, both surface profiles and the deformation fields of the composites were visualized which was helpful to compare each other to analyze the damage of those heterogeneous materials. The project supported by the National Natural Science Foundation of China (10125211 and 10072002), the Scientific Committee of Yunnan Province for the Program of Steel Fiber Reinforced Concrete, and the Institute of Chemical Materials, CAEP at Mianyang     

高剥离类镁等电子序列的磁偶极M1和电四极E2光谱跃迁理论研究

利用全相对论性多组态Dirac-Fock广义平均能级方法，系统地计算了类镁离子3s3p磁偶极Ml^3P2--^3P1和电四极E2 ^2P2--^3P0(Z=20-103)光谱跃迁的能级间隔、跃迁几率和振子强度。计算中考虑了原子核的有限体积效应，进行了高阶Breit修正和QED修正，所得到的能级间隔和最近的实验数据及理论计算值进行了比较。计算结果表明：高原子序数的高荷电离子的磁偶极矩M1和电四极矩E2跃迁几率和中性原子的电偶极E1的相当，在ICF和MCF高温激光等离子体中，磁偶极矩M1和电四极矩E2跃迁过程不容被忽视。     

圆锥曲线焦点弦的一个性质

笔者在利用《几何画板》探索圆锥曲线的性质时 ,发现圆锥曲线的焦点弦和准线间存在一个有趣性质 ,在此给出 ,共大家分享 .我们先看一个引理 :引理　在极坐标系中 ,设A(ρ1,θ1) ,B(ρ2 ,θ2 )是圆锥曲线 ρ=ep1 -ecosθ 上任意两点 ,则直线AB的方程为 :ρ[cos(θ1+θ22 -θ) -ecosθ1-θ22 cosθ]=epcosθ1-θ22 .证明　在极坐标系中 ,若A(ρ1,θ1) ,B(ρ2 ,θ2 ) ,则直线AB的方程是 :sin(θ1-θ2 )ρ =sin(θ1-θ)ρ2+sin(θ -θ2 )ρ1( )因为A(ρ1,θ1)、B(ρ2 ,θ2 )在圆锥曲线 ρ =ep1 -ecosθ上 ,所以 ρ1=ep1 -ecosθ1,ρ2 =ep1 -…     

共形不变标量场在Reissner-Nordsttr?m时空的Boulware 态中的重整化能动张量

利用Page-Zannias方法并借助微机和REDUCE语言计算了共形不变标量场在Reissner-Nordsttr?m(R-N)时空中Boulware态的重整化能动张量。 关键词：     

图的度序列不等式

用代数的方法证明了有关图度序列的几个不等式，并且得到了其相应的极图。     

光致折射效应中空间电荷场建立过程的研究

本文推导了包含自衍射及非线性吸收影响、用以描述空间电荷场建立过程的微分方程组,阐明了周期性的空间电荷场与光强干涉条纹之间的相位差在建立过程中所起的作用,并推导了描述条纹倾斜和弯曲的微分方程。通过数值计算找到了硅酸铋(BSO)晶体中能量转移的规律,讨论了材料特性对过程快慢的影响,提出了用CW激光来探讨瞬态过程快慢的可能性。     

B-Spline with Symplectic Algorithm Method for Solution of Time-Dependent Schrodinger Equations

A B-spline with the symplectic algorithm method for the solution of time-dependent Schrodinger equations （TDSEs） is introduced. The spatial part of the wavefunction is expanded by B-spline and the time evolution is given in a symplectic scheme. This method allows us to obtain a highly accurate and stable solution of TDSEs. The effectiveness and efficiency of this method is demonstrated by the high-order harmonic spectra of one-dimensional atoms in comparison with other references.     

带有背景矢量场的标量场暗能量模型

讨论了带有背景矢量场的动力学标量场作为暗能量在闭宇宙的情形下的演化. 选取适当的标量场势函数后, 在得到的暗能量有效状态方程中, 参数w在红移z≈0.2处可以越过－1, 而且在z≈1.7处宇宙从减速膨胀的状态转变为加速膨胀状态, 这与最近的宇宙学观测相符.