超短脉冲贝塞尔光束的非近轴效应对传输的影响

 对超短脉冲贝塞尔光束在近轴近似和非近轴情况下自由空间中的传输作了研究。结果表明，其空间波形在传输中保持贝塞尔形状不变，不受非近轴效应影响；然而当空间参数较大时，非近轴效应影响超短脉冲贝塞尔光束的时间波形。     

激光辐照PC型HgCdTe探测器的实验研究

 分别用连续波1.319μm激光和10.6μm激光辐照PC型HgCdTe红外探测器时，得到了不同辐照光功率密度下，探测器输出的一系列实验结果。给出了在波长为1.319μm的波段内激光辐照下PC型HgCdTe探测器的饱和阈值；用波长为10.6μm的波段外CO₂激光辐照探测器时，发现了一些与波段内激光辐照探测器时大不相同的实验现象；对实验结果进行了分析。简要总结了PC型HgCdTe探测器对于波段内和波段外激光辐照的响应机制。     

气相毛细管柱切割-反吹技术及归一化法分析汽油中的芳烃(英文)

 发展了一种采用毛细管气相柱切割 反吹技术分析汽油中芳烃的方法。利用强极性毛细管预柱将芳烃保留至n C10 的脂肪族化合物之后 ,并将其反吹到非极性毛细管柱中按沸点详细分离分析。该方法使预柱先流出的组分和分析柱流出的组分通过一个微型三通进入同一检测器中 ,因此可用归一化方法定量分析汽油中的芳烃。该方法可在 15min内完成汽油中苯至C10 芳烃的分析 ,结果的相对标准偏差 (RSD)≤ 3% ,切割误差为± 5s时分析结果的RSD≤ 4 %。     

Vibrational and lifetime line broadenings in ESCA

The line profile of the narrow, symmetric 1s line from neon, recorded with the new ESCA instrument with X-ray monochromatization, is analyzed. The natural linewidth of this line is found to be 0.23 ± 0.02 eV, in good agreement with theoretical calculations of the oscillator strengths for Auger transitions and X-ray emission. Spectra from molecules show frequently asymmetric core electron lines under high resolution. This rules out previous explanations based on a chemical influence on the natural lifetime. Contrary to earlier assumptions, vibrational excitations are shown to be important in core electron spectra. For methane, the vibrational energy spacing is large enough to allow the vibrational lines to be partly resolved. Recent results from accurate PNO CI calculations on methane agree well with the experimental findings. The Franck-Condon transitions in the C1s and N1s lines from CO and N₂ are shown to be well described in the harmonic approximation and approximating the potential curves of the highly excited core hole states with the potential curve for the ground state of NO⁺, X¹ Σ⁺. Knowledge of vibrational excitations in core electron spectra is shown to be valuable in the analysis of high resolution X-ray emission spectra of free molecules.     

The D<Superscript>1</Superscript>Π state of the NaRb molecule

We present a detailed experimental study of the D¹Π state of the NaRb molecule by means of Fourier transform spectroscopy of laser induced fluorescence. The entire data field for the D¹Π state of Na⁸⁵Rb and Na⁸⁷Rb consists of rovibrational levels with v^′=0-39 and J^′=1-200. The data were incorporated into a direct fit of a single potential energy curve to the level energies using the Inverted Perturbation Approach method. The D¹Π state q factors, which describe the Λ-doubling, have been obtained in a wide range of rotational and vibrational quantum numbers. Analysis revealed several perturbation regions in the D¹Π state. Electronic supplementary material Online Material     

The phase diagram of the multi-dimensional Anderson localization via analytic determination of Lyapunov exponents

The method proposed by the present authors to deal analytically with the problem of Anderson localization via disorder [J. Phys.: Condens. Matter 14, 13777 (2002)] is generalized for higher spatial dimensions D. In this way the generalized Lyapunov exponents for diagonal correlators of the wave function, 2n,m , can be calculated analytically and exactly. This permits to determine the phase diagram of the system. For all dimensions D > 2 one finds intervals in the energy and the disorder where extended and localized states coexist: the metal-insulator transition should thus be interpreted as a first-order transition. The qualitative differences permit to group the systems into two classes: low-dimensional systems (2D 3), where localized states are always exponentially localized and high-dimensional systems (D Dc=4), where states with non-exponential localization are also formed. The value of the upper critical dimension is found to be D0=6 for the Anderson localization problem; this value is also characteristic of a related problem – percolation.     

同位素示踪法的开创者——赫维西

19世纪末20世纪初是物理化学和生物化学发展的重要时期,同位素示踪法在一系列示踪剂实验方面取得了许多成就。瑞士籍匈牙利裔化学家乔治·德·赫维西(1885—1966)将示踪技术应用到生物学领域,他有关同位素示踪法的发明也使其获得了1943年诺贝尔化学奖。本文对赫维西生平及学术成长历程进行介绍,反映了赫维西的成长与欧洲当时的诸多科学家之间的学术往来是不可分割的。     

高能飞秒激光系统中空间滤波器的研究和设计

 由于透镜传输时间延迟效应（PTD），飞秒激光脉冲经过空间滤波器产生脉冲波前变形。讨论了用双胶合透镜或双分离透镜代替空间滤波器中的单透镜，以消除或减小PTD效应，设计了适用于飞秒激光装置的空间滤波器。     

多元探测器在玫瑰扫描红外亚成像系统中的应用

玫瑰扫描红外亚成像系统是利用玫瑰扫描机构和红外单元探测器构成的一种亚成像系统。提出了一种利用多元小面阵来替代单元探测器的红外亚成像系统 ,可以提高成像系统的空间分辨率和帧频。分析了系统的原理 ,并给出了系统的构成框图。此外 ,就玫瑰扫描成像系统中应用多元探测器可能出现的问题进行了讨论 ,并提出了解决方案。结果表明 ,这种多元小面阵玫瑰扫描成像系统的成本远低于焦平面阵列探测器红外成像系统 ,在性能改善后是诸如末制导炮弹等低成本应用场合的理想红外成像系统