飞秒啁啾脉冲放大系统中折叠反射式望远镜对脉冲波前的影响

推导出飞秒激光啁啾脉冲放大系统中使用的折叠反射式望远镜对脉冲波前的影响. 分析和计 算了波前倾斜与反射式望远镜参数之间的关系.结果发现：当脉冲宽度小于100 fs时，波前 倾斜对光束质量的影响不可忽略，并提出了抑制这种脉冲波前倾斜的有效方法. 关键词： 飞秒激光啁啾脉冲放大 波前倾斜 反射式望远镜     

Spectra and Spin Polarization of the Valence Band Auger Emission from Cr （100） Surface

Calculations have been carried out on spin-polarized Auger electron emission from a seven-layer chromium (lO0)-film. The core and valence states concerning the Auger transition are obtained from a self-consistent full-potential linearized augmented plane wave calculation by using a repeated slab geometry. The calculations refer to experiments on the L3M23 V- and L3 VV-transRions that have recently been carried out by Heinzmann et al. The Auger spectrum obtained for the L3VV transition agrees relatively well with our calculations, whereas the observed L3M23V-Auger structure is considerably wider than that predicted by our theory. Nevertheless, the spin-polarization in the latter case, which is about -13%, is in fair agreement with the experiment, different from the L3VV-transition where the experiment yields -10% as opposed to the theoretical value of -25%. We give possible reasons for the origin of these discrepancies.     

正、余弦定理的叠用与联用

在国内外的各级各类数学考试中,有许多几何试题,初看起来非常棘手,但如能巧妙联用或叠用正、余弦定理,常能使问题非常迅速地得到简解。     

Low—Lying Resonance States of Slow Electron Collisions With Atomic Oxygen

A 39-target state close-coupling calculation of low-energy electron scattering from atomic oxygen is carried out with core-valence electron correlation by using R-matrix method. It is shown that the elastic cross section has a huge and sharp increase with the electron energy going down below 1eV. This remarkable structure is attributed to a few very low-lying potential resonances and the features of these resonances are given with partial cross sections. It is also shown that after considering excitations of two electrons from 2s shell, the three lowest atomic energy levels are in agreement with experimental results better than that just considering excitations of two electrons from the 2p shell as well as only one electron from the 2s shell. Elastic and two excitation (^3P→^1D and ^3P→^1S) cross sections are given and compared with the other theoretical and experimental results.     

A=40—70偶中子核素光子穿透系数的关联现象

本文给出了在共振区光子穿透系数的表示式,它由三部份组成,分别对应复合核统计过程、复合核弹性散射道及非弹性散射道中的辐射退激过程.研究了在中子强度函数3s巨共振区13个偶中子核素的中子辐射俘获截面.中子能量范围为3MeV以下的共振区.结果表明,在同时考虑了统计和非统计过程后,可以解释实验测量的总俘获截面及γ能谱.     

Born—Infeld方程与极值曲面

本文是研究具有孤立子解的Born-Infeld方程,证明了它的解曲面是三维Minkowski空间M~(2.1)中的极值曲面,并应用Legendre变换在不同区域构造了解曲面的参数表达式。     

不可压缩流体平面流动分离的充分判据

本文研究了不可压缩流体平面流动的分离判据问题。得到了比文献[1]更为普遍的分离的充分判据,即定理一。文中指出,MRS判据,零涡判据,奇点判据以及文献[2]的判据在非定常流动中均不是充分的。     

(C,α,ρ,d)-凸极大极小分式规划的最优性条件

定义了一类存在性更为广泛的广义凸性，（C，α，ρ，d）-广义凸；获得了在非光滑情形下极大极小广义分式规划的最优性必要条件；利用（C，α，ρ，d）-广义凸性我们得到了极大极小广义分式规划的最优充分性条件。     

Theoretical simulations of emission spectra of Fe^7＋ and Fe^＋8

The energy levels, oscillator strengths, spontaneous radiative decay rates, and electron impact collision strengths are calculated for Fe VIII and Fe IX using the recently developed flexible atomic code （FAC）. These atomic data are used to analyse the emission spectra of both laboratory and astrophysical plasmas. The nf-3d emission lines have been simulated for Fe VIII and Fe IX in a wavelength range of 6-14 nm. For Fe VIII, the predicted relative intensities of lines are insensitive to temperature. For Fe IX, however, the intensity ratios are very sensitive to temperature, implying that the information of temperature in the experiment can be inferred. Detailed line analyses have also been carried out in a wavelength range of 60-80 nm for Fe VIII, where the solar ultraviolet measurements of emitted radiation spectrometer records a large number of spectra. More lines can be identified with the aid of present atomic data. A complete dataset is available electronically from http：//www.astrnomy.csdb.cn/EIE/.     

环形激光陀螺随机误差测试中的计数误差

详细讨论了环形激光陀螺（RLG）误差测试中的计数误差。首先提出了在角度随机游走为主要误差源的情况下，RLG的离散输出模型。在假设累积角度量化误差为白噪声的前提下推导了方差（或AIlan方差）分析中的量化误差模型。接着指出白噪声假设并不总能成立，特别是对于由计数器只能计整数引致的量化误差（特称为“计数误差”），由于量化间隔很大，这一假设通常不能成立。最后，给出了一种白噪声假设不能成立时的处理方法及仿真数据分析结果。