超声射流冷却SO2^—A2—^1A1激光诱导荧光激发谱

测得了３１５￣３３０ｎｍ超声射流冷却下ＳＯ２＾１Ａ２－＾１Ａ１激光诱导荧光（ＬＩＦ）激发谱，获得了７个有明显Ｋ结构的Ｃ型跃迁的转动子带分辨谱，并将７０个转动子带归属为（１，ｍ，１）－（０，０，０）和（０，ｎ，１）－（０，０，０）（４≤ｍ≤７，８≤ｎ≤１０）的跃迁带系。光谱分析得到ＳＯ２＾１Ａ２－＾１Ａ１跃迁的带源ｖ００、＾１Ａ２态弯曲振动频率ｖ′２，非谐性常数Ｘ２２′分别为（２７９５０±５）、（２     

人工神经网络方法预测八面体六卤化物MX^n—6的v1和v2模的振…

利用ＡＮＮ－ＢＰ算法，采用逐步改变训练步长和两个惯性项的权重系数惯性调整策略，分别以单目标和双目标的三层网络对八面体六卤化物ＭＸ＾ｎ－６的八面体ｖ１和ｖ２模振动频率进行了预测，发现单，双目标下预测的结果相差不大，双目标时权重系数调整科较快，（ＭｏＦ６）＾２－（ＢｉＦ６）＾－和（ＡｕＦ６）＾２－的振动频率文献值与网络的计算值或预测值相差偏大。     

N（4Su）＋CH）（a^4Σ^—）体系的分子反应动力学研究

用轨线法对Ｎ（＾４Ｓｕ）＋ＣＨ（０,０）→ＣＮ（ｖ＇,Ｊ＾＇）＋Ｈ（Ｓｇ）和Ｎ（＾４Ｓｕ）＋ＣＨ（０,０）→ＮＨ（ｖ＇,Ｊ＇）＋Ｃ（＾３Ｐｇ）反应进行计算,研究了上反应的阈能、反应截面、产物散射分析和微观反应机理。     

NⅢ—ArⅩⅣ离子的双电子激发六重态跃迁的理论计算

根据相对论多组态理论，采用ＧＲＡＳＰ２（１９９２）程序计算了ＮⅢ—ＡｒⅩⅣ的１ｓ２ｓ２ｐ３６Ｓ０－１ｓ２ｓ２ｐ２３ｄ６Ｐ跃迁精细结构，计算的波长值与Ｊ．Ｈ．Ｂｌａｎｋｅ［１］等人的计算值和实验值进行了比较，并为六重态离子谱线辨识提供了有益的参考。     

束—气条件下He（2^3S）＋CH2Cl2碰撞传能反应的动力学研究

本文在束－气条件下研究了亚稳态原子Ｈｅ（２＾３Ｓ）与ＣＨ２Ｃｌ２间的传能反应，测得了由该反应产生的ＣＨ（Ａ＾２△－Ｘ＾２П），ＣＨ（Ｂ＾２∑＾－Ｘ＾２П）ＣＨ（Ｃ＾２∑＾＋－Ｘ＾２П）和Ｈ原子（Ｂａｌｍｅｒ系）的化学发光光谱。通过对ＣＨ（Ａ，Ｂ）的光谱进行计算机模拟，推测出初手的ＣＨ（Ａ＾２△，ｖ＾１＝０－２）态振动分布为Ｎｏ：Ｎ１：Ｎ２＝１００：４０±５：１９±２，ＣＨ（Ａ＾２△，ｖ＾１＝０－０     

e／f宇称对CO（A^1П）振动传能截面的影响

采用光学双共振多光子电离技术在静态池条件下测量了ＣＯ Ａ＾１П（ｖ＝３）能级上的绝对（Ｊ→Ｊ＇）转动传能截面，其中在Ｊ＝３￣１６、（ｅ，ｆ）被选择研究了；碰撞拌分别为Ｈｅ、Ｎｅ、Ａｒ、ＨＣｌ、ＣＯ２。在以上传能过程中发现明显的宇称守恒的倾向性规则。用能隙规则能很好地拟合大部分实验数据，并且采用Ａｌｅｘａｎｄｅｒ等人的非弹性散射理论来解释宇称守恒定则。但是，当ΔＪ＝０时，对于碰撞伴Ａｒ、ＨＣｌ、ＣＯ     

Br2分子里德堡态的高分辨转动谱研究

用窄线宽（０．０８ｃｍ＾－＾１）脉冲可调谐紫外激光和（２＋１）多光子电离方法测量了Ｂｒ２的里德堡（Ｒｙｄｂｅｒｇ）态光谱,在７００００－７１５００ｃｍ＾－＾１范围内,获得了溴分子［П３／２］４ｄ振动系列,测量（ｖ＇,ｖ”）＝（１,０）,（２,０）的高分辨振转谱,得到其转动常数Ｂ’７９－８１分别为０．０８８３２和０．０８８０５ｃｍ＾－＾１,并提出此系列的角动量量子数Ω应为１。     

点价δ^v的改造及其对AnBm型过渡元素化合物△fHm^Φ的相 …

定义了有效价电子数Ｚｉ，引入了成键电子数ｍｉ，并对分子中原子点价δ＾ｖ重新定义为δｉ，用δ＾ｖ和δｉ构成的分子结构参数Ｘ＾ｖ和Ｘ对３３个ＡｎＢｍ型过渡元素卤化物标准生成焓的相关性研究表明，要关系数分别为０．９０９９，０．９４００。在δｉ中如用价电子数Ｚｉ代替Ｚｉ，则相关系数仅为０．９２３５。     

H3^＋和H4^＋分子的几何构型与性质

用从头算法得到Ｈ３＾＋只有唯一构型，而Ｈ４＾＋则有１０种不同的可能构型存在，其中包括Ｄ２ｈ、Ｄ∞ｈ、Ｃ３ｖ、Ｃ２ｖ等不同的几何构型。同时，计算表明Ｈ４＾＋和Ｈ４＾＋是不能稳定存在的，并详细地讨论了其Ｊａｈｎ－Ｔｅｌｌｅｒ效应。     

飞秒光脉冲光纤放大增益特性的实验研究

报道了掺Ｅｒ＾３＋光纤激光器输出１．５３１μｍ波长飞秒激光脉冲增益放大的实验研究结果,将自起振相加脉冲摹参Ｅｒ＾３＋光纤激光器输出的飞秒激光脉冲注入掺Ｅｒ＾３＋光纤放大器中进行放大,分别采用正向和逆向抽地这的方式,得到了最高放大倍数５５倍（１７．４ｄＢ）和６４倍（１８．１ｄＢ）的增益,对应的最大单脉冲能量（峰值功率）分别为０．３８４ｎＪ（７５２Ｗ）０．４５２ｎＪ（１２９５Ｗ）,脉冲重复率为２０．８     

关于HBr分子爱因斯坦自发辐射系数的一种理论计算方法

 采用双原子分子光谱参数计算程序LEVEL，分别选用目前最好的解析势能函数之一的Murrell-Sorbie函数和精确的RKR势，数值求解径向薛定谔方程，得到振转能级的本征能量和本征波函数。选用公开发表的最新的电偶极矩函数，计算得到了HBr分子X1Σ+态振动能级低于7时R和P支基频跃迁谱线的爱因斯坦自发辐射系数。     

Adsorption of HCl and HBr on Si(111): AES,ELS, and EID studies

The combined techniques in situ of Auger electron spectroscopy, electron energy loss spectroscopy, electron impact desorption, and work-function change measurement have been applied to the study of the adsorption of HCl and HBr on thermally cleaned Si(111) surfaces. Major results are summarized as follows: (1) HCl shows a fast adsorption to the saturation coverage of $\text{θ}{}_{\mathrm{s}}\text{? 0.3}$ (estimated using the continuum approximation) by the exposure of about 1 L at room temperature. (2) The average sticking probabilities for HCl and HBr are ～0.7. (3) Two adsorbed states of HCl or HBr at room temperature are discriminated. For HCl, the first state is characterized by the emission of ～1.2 eV ions and the electronic transition at 8.4 eV, which is subsequently converted to the second state characterized by the emission of ～3.2 eV ions and the electronic transitions at 7.0 and 8.4 eV. Heating the sample at ～800 K causes the desorption of hydrogen and the appearance of the Cl-related peaks at 6.0, 7.0, and 9.0 eV in the loss spectra. For HBr, the first and the second states are characterizied by the emission of ～1.2 and ～3.2 eV ions, respectively. The electronic transition is observed at 7.8 eV in both states. (4) It is proposed that HCl and HBr are adsorbed as molecules initially, which are subsequently dissociated into atoms spontaneously at room temperature.     

Forbidden rotational spectra of axially symmetric polar molecules

In this paper we consider the rotational transitions induced by centrifugal distortion in polar or quasipolar symmetric top molecules belonging to the point groups C_n and C_nv (n ≥ 3). It is shown that in this series only the molecules of point groups C₃, C_3v, C₄, and C_4v may possess rotational spectra induced by first-order centrifugal distortion. A general expression is given for the effective dipole moment operator and for its matrix elements. The peak absorption coefficients for some of the strongest ΔK = 3 transitions of the CH₃D molecule have been calculated and compared with the peak absorption coefficients of allowed transitions.     

Superlattices formed by interaction of hydrogen bromide and hydrogen chloride with Pt(111) and Pt(100) studied by LEED,Auger and thermal desorption mass spectroscopy

HBr and HCl react with Pt(111) and Pt(100) surfaces to form adsorbed layers consisting of specific mixtures of halogen atoms and hydrogen halide molecules. Exposure of Pt(111) to HBr yielded a (3×3) LEED pattern beginning at $\text{Θ}{}_{\mathrm{Br}}\text{=}\text{2}\text{9}$ and persisting at the maximum coverage which consisted of $\text{Θ}{}_{\mathrm{<mtext>Br</mtext>}}\text{=}\text{1}\text{3}$ plus $\text{Θ}{}_{\mathrm{<mtext>HBr</mtext>}}\text{=}\text{1}\text{9}$. The most probable structure at maximum coverage, Pt(111)[c(3 × 3)]-(3 Br + HBr), nas a rhombic unit cell encompassing nine surface Pt atoms, and containing three Br atoms and one HBr molecule. On Pt(100) the structure at maximum coverage appears to be Pt(100)[c(2√2 × √2)]R45°-(Br + HBr), $\text{Θ}{}_{\mathrm{<mtext>Br</mtext>}}\text{= Θ}{}_{\mathrm{<mtext>HBr</mtext>}}\text{=}\text{1}\text{4}$; the rectangular unit cell involves four Pt atoms, one Br atom and one HBr molecule. Each of these structures consists of an hexagonal array of adsorbed atoms or molecules, excepting slight distortion for best fit with the substrate in the case of Pt(100). Treatment of Pt(100) with HCl produced a diffuse Pt(100)(2 × 2)-(Cl + HCl) structure at the maximum coverage of Θ_Cl = 0.13, Θ_HCl = 0.11. Exposure of Pt(111) to HCl produced a disordered overlayer. Thermal desorption, Auger spectroscopy and mass spectroscopy provided coverage data. Thermal desorption data reveal prominent rate maxima associated with the structural transitions observed by LEED. Br and HBr, Cl and HCl were the predominant thermal desorption products.     

Absorption intensities for vibration-rotation bands and the dipole-moment expansion of HBr

Line intensities in the four 0–2, 0–3, 0–4, 0–5 vibration-rotation bands of HBr were measured. The electric dipole matrix elements 〈0|M|ν'〉 for vibrational transitions with ν'?5 have been calculated by using a Dunham potential and the analytical solution of the Schrödinger equation described by R.H. Tipping. A dipole-moment expansion accurate to M₅ was determined by fitting these matrix elements to the available experimental data on line intensities. The experimental results were also used to calculate the Einstein coefficients of the R₀ lines for the bands ν' → ν′' with ? ν' ? 5.     

Infrared spectral line parameters of HBr and DBr at elevated temperatures

The electric dipole matrix elements <v'J'μvJ> for pure rotation and vibration-rotation transitions, with |;m|;<-40 and v<-v'<-6, have been derived for HBr and DBR by using the Rydberg-Klein-Rees (RKR) potentials and numerical solutions of the Schrödinger equation. An improved dipole-moment expansion was determined by fitting these matrix elements to the available experimental data on line intensities. A least squares analysis of the available line position constants gave an improved set of Dunham coefficients good for spectral lines with both large and small quantum numbers v and J. The results were then used to generate a compilation of individual line parameters for the Δv = 1 bands of HBr and DBr at temperatures up to 3000K. These parameters, together with previously compiled line parameters for HCl, HF, CO and NO, are being used for line-by-line calculations of radiance from a hot source as seen through an atmospheric path.     

Quantum transitions of relativistic electrons in a superstrong magnetic field

The probability of emission of a hard γ-quantum in relativistic electron transitions to the ground (or near it) level in a magnetic field H ～ H₀ = m²c³/e₀? = 4.41 × 10¹³G is obtained. For the inverse transitions from these levels the cross-section of electron photoexitation is calculated.     

Discharge studies of the lithium dimer diffuse bands

We report the observation of lithium dimer diffuse bands in the region from 410 nm to 460 nm emitted from a low-power discharge sustained inside a heat-pipe oven. The identification of the lithium diffuse band as a specific feature originating from the transitions from higher excited levels of the Li₂ molecule was supported by the construction of the emission profile in terms of recently calculated potential energy curves, relevant transition dipole moments and application of the modified quasi-static theory of the satellite band shape.     

Simultaneous ejection of two molecular ions from keV gold atomic and polyatomic projectile impacts

We present the first experimental data on the simultaneous ejection of two molecular ions from the impact of Au(+)(n) (1< or =n< or =4) with energies ranging between 17 and 56 keV. The yields from single phenylalanine (Ph) emission, coemission of two Ph ions, and emission of the Ph dimer were measured. Large increases (1 to 2 orders of magnitude) in coemitted ion yields were observed with increasing projectile energy and complexity. Correlation coefficients were calculated for the coemission of two Ph ions; their behavior suggests differences in emission pathways for bombardment by atomic and polyatomic projectiles.     

Broadening and shift of the spectral line centers of a molecule upon strong vibrational excitation

Half-widths and shifts of the line centers of the excited CO molecule caused by transitions between highly excited rovibrational states are calculated. Strong intramolecular effects caused by vibrational excitation are considered in the calculations. It is revealed that the vibrational dependence of the line broadening and shift coefficients is nonmonotonic, and the coefficients can change several times.