Electron-vibrational interaction in 4f-5d optical transitions in Ba, Ca, Sr thiogallates doped with Eu ions

This study is devoted to the problem of the electron-vibrational interaction in 4f-5d optical transitions. We analyze the room temperature experimental data on the vibronically assisted broad bands arising from the 4f-5d transitions in Ba, Ca, and Sr thiogallates doped with Eu²⁺ ions. An approximate simple expression is given for the shape function of the broad vibronic bands with allowance for the terms corresponding to the emission (absorption) from both ground and first excited vibrational levels. We estimate the vibronic coupling parameters and the Stokes shifts for these systems. The theoretical results are in a good agreement with the experimental data.     

Thinking and Turing's test

The questions raised by A. M. Turing in his paper on thought and machines are discussed. Human thought is considered in turn as a concept of normal language usage, as a basic concept of psychology, and as the basis of intellectual activity. It is concluded that neither of these notions of thought identifies something specific that a human being can or cannot do. The imitation game proposed by Turing for deciding whether a machine can think is found to result from an arbitrary empoverishment of the channel of communication between the interrogator and the item under investigation. Turing's notions of thinking are shown to lead to logical difficulties. An alternative view of consciousness, that would place it beyond the reach of any finite test, is finally discussed.     

路与完全图的笛卡尔积图和广义图K(n,m)的关联色数

Richrd A.Brualdi和J.Quinn Massey在[1]中引入了图的关联着色概念,并且提出了关联着色猜想,即每一个图G都可以用△(G)+2种色正常关联着色.B.Guiduli[2]说明关联着色的概念是I.Algor和N.Alon[3]提出的有向星荫度的一个特殊情况,并证实[1]的关联着色猜想是错的,给出图G的关联色数的一个新的上界是△(G)+O(Log(△G)).[4]确定了某些特殊图类的关联色数.本文给出了路和完全图的笛卡尔积图的关联色数,而且利用此结果又确定了完全图Kn的广义图K(n,m)的关联色数.     

多段阵列式放大器特性的计算模拟

考虑了从电容器储能到激光介质储能的多个能量转换环节,引入时间因子和三维空间放大自发辐射,对多段阵列式放大器９ＭＳＡ）性能作了详细的计算模拟,包括多段阵列式放大器的中间和边缘闪光阵列间的泵浦平衡、储能、增益系数和增益分布等重要激光参数随时间的变化,利用利弗莫尔实验室的实验参数对本文的程序进行了校核,并演示了该程序的预估能力。     

微腔中两原子缀饰态的二光子衰变

研究了微腔中原子衰变问题。考虑微腔中存在两个原子,两原子与腔场强耦合形成的缀饰原子与腔壁相互作用在特定初始条件下的衰变问题,指出在腔场中该衰变方式下,腔场光子数越多、衰变则越强     

衰减相移掩模及其编码制作方法研究

在霍普金斯理论的基础上,对方孔的传统掩模、衰减相移以及加入光学邻近效应校正的衰减相移掩模在硅片表面光强分布的计算表明,衰减相掩模有提高光刻分辨率的显著功能,提出一种制作衰减相移掩模的编码方法。理论计算表明,该编码方法能够达到预定的衰减参数。     

多模干涉型GaAs光功分器的研制

采用导模传输分析法设计了多模干涉型１×４ 光功分器。根据所确定的器件结构参数, 结合器件设计和制作过程中可能遇到的因素, 详细分析了器件中自映像效应多模波导的宽度和长度、波导的折射率等结构参数对器件性能的影响。进行了多模干涉型 Ｇａ Ａｓ １×４ 光功分器的制作和测试。测试结果表明, 所研制的器件实现了１×４ 光功分器功能。针对实验过程和测试结果中遇到的问题进行了讨论, 并提出了进一步完善器件性能的方法。     

The electronic structure of molecules by a many-body approach

The vertical valence ionization potentials of cyclopropane, ethylene oxide and ethylene imine are calculated by a many-body Green's function method. For C₃H₆ the ordering of the ionization potentials is 2e(), 1e(), 2a₁(), 1a₂(), 1e(). The assignment of the 2a₁ and the 1a₂ ionization potentials which has been controversial is thus clarified. The ordering is in agreement with the result obtained via Koopmans' theorem. For ethylene oxide and ethylene imine Koopmans' theorem fails in predicting the correct order of ionic states. For C₂H₄O the ordering of the ionization potentials is 2b ₁(), 4a ₁, 1a ₂(), 2b ₂,3a ₁, 1b ₁(), 1b ₂, 2a ₁ and for C₂H₅N 6a, 5a, 3a, 2a, 4a, 3a, 1a, 2a. The agreement of the computed ionization potentials with the experimental values is very satisfactory.     

Composition and properties of freeze-dried products of nicotinic acid withβ-cyclodextrin and heptakis (2,6-0-dimethyl)-β-cyclodextrin

The purpose of the study was to examine the formation of inclusion compounds in the freeze-dried products obtained from aqueous solutions of nicotinic acid and -cyclodextrin (-CD), or heptakis (2,6-0-dimethyl)--cyclodextrin (DIMEB). The molar ratios used were 1:1 and 2:1. In addition two freezing temperatures (–40 and –196°C) and different secondary drying temperatures (+50 and +80°C) were used. Freeze-dried products with -CD obtained after low temperature freezing are of the same crystallographic structure as seen in a pure inclusion compound prepared by coprecipitation. Amorphous products were formed after fast freezing. The molar ratios of included nicotinic acid in the freeze-dried products vary — dependent on the preparation conditions — between 0.75:1 and 1:1. A factorial design proves that the included drug amount can be increased by enhancement of the amount of nicotinic acid used, by faster freezing, and by the combination of these two factors. The proof of inclusion formation was given by a combination of X-ray diffractography, differential scanning calorimetry, thermogravimetry and thermofractography.The freeze-dried preparations obtained with DIMEB were amorphous mixtures of the two components. No proof for inclusion of the nicotinic acid in the cyclodextrin cavity could be given. Higher (–40°C) or lower (–196°C) freezing temperatures and the running of the secondary drying process could not influence these results. The very low stability constant of the complex and steric reasons are responsible for this behavior.     

太阳CO 4.6微米红外成像观测

太阳红外光谱中蕴含着丰富的物理信息,其中CO 4.6μm波段是具有代表性的分子谱带,其形成于温度极小区附近,对研究太阳物理具有极其重要的意义。为获得CO 4.6μm波段太阳单色像,本文建立了一套全反射太阳红外成像观测系统。该系统采用定天镜跟踪引光,通过成像反射镜将太阳成像于3~5μm波段红外相机的焦平面上,该相机采用的是国产HgCdTe焦平面阵列器件。同时,为提高信噪比,提出了一种有效计算平场提取观测目标的方法,并利用该方法获得了CO 4.6μm波段的太阳单色像。