溴乙烷的同步辐射光电离解离

在超声射流条件下,利用真空紫外同步辐射光辐照和飞行时间质谱,研究溴乙烷光电离及解离电离的动力学。通过测量光电离及解离电离产生的碎片离子的光电离效率（ＰＩＥ）曲线型分布获得了溴乙烷的电离势和各碎片离子的出现势,并结合标准的已确认的热力学数据,计算了离子的标准生成焓,估算了有关分子的键能及母体离子的解离能,并对溴乙烷分子真空紫外光解离电离通道进行了分析。     

环戊酮光电离解离的实验和理论研究

本文介绍了真空紫外光电离质谱结合理论计算研究环戊酮单分子的光电离解离过程. 在9.0∽15.5 eV能量范围内,测量了环戊酮离子及其碎片离子的光电离效率曲线. 通过光电离效率曲线,将环戊酮分子的电离能确定为9.23±0.03 eV,并确认碎片离子为：C₅H₇O⁺,C₄H₅O⁺,C₄H₈⁺,C₃H₃O⁺,C₄H₆⁺,C₂H₄O⁺,C₃H₆⁺,C₃H₅⁺,C₃H₄⁺,C₃H₃⁺,C₂H₅⁺, C₂H₄⁺. 利用量子化学计算方法,在ωB97X-D/6-31+G(d,p)理论水平基础上,提出了C₅H₈O⁺的解离机制. 通过对环戊酮解离路径的分析,发现开环和氢迁移过程为环戊酮离子解离的主要路径.     

HFC-152a的同步辐射真空紫外光电离和光解离研究

利用同步辐射真空紫外光，研究了HFC-152a(CH₃CHF₂)的光电离和光解离过程，通过测量各离子的光电离效率曲线，得到了该分子的电离能(11.94±0.04eV)和所有碎片离子的出现势，运用GAUSSIAN-03程序计算了母体和碎片及相应离子的结构、电子态和能量. 结合理论计算的结果，分析了母体离子可能的光电离解离通道及相关通道的解离能. 关键词： 同步辐射 光电离 出现势 HFC-152a     

1,2-环氧辛烷的同步辐射光电离解离研究

利用同步辐射产生的真空紫外光和反射式飞行时间质谱仪,在超声冷却条件下测量了1,2-环氧辛烷在光子能量9.8~16.6 eV能区的光电离解离过程,获得了不同能量光子作用下的电离解离产物。通过测量各离子的光电离效率曲线,得到了主要碎片离子的出现势。结合G3理论计算得到了母体离子、中性碎片及离子碎片的结构与能量,通过对比实验测量值与理论值给出了1,2-环氧辛烷的光电离解离通道.     

环戊酮光电离解离的实验和理论研究（英文）

本文介绍了真空紫外光电离质谱结合理论计算研究环戊酮单分子的光电离解离过程,在9.0～15.5 eV能量范围内,测量了环戊酮离子及其碎片离子的光电离效率曲线.通过光电离效率曲线,将环戊酮分子的电离能确定为9.23±0.03eV,并确认碎片离子为:C_5H_7O~+,C_4H_5O~+,C_4H_8~+,C_3H_3O~+,C_4H_6~+,C_2H_4O~+,C_3H_6~+, C_3H_5~+,C_3H_4~+, C_3H_3~+, C_2H_5~+,C_2H-4~+.利用量子化学计算方法,在ωB97X-D/6-31+G(d,p)理论水平基础上,提出了C_5H_8O~+的解离机制.通过对环戊酮解离路径的分析,发现开环和氢迁移过程为环戊酮离子解离的主要路径.     

丙烯腈的真空紫外光电离研究

利用同步辐射真空紫外光和飞行时间质谱,研究了丙烯腈的真空紫外光电离解离过程。通过测量各离子的光电离效率曲线,获得了丙烯腈的电离势和各种碎片离子的出现势。分析了主要碎片离子的光电离解离通道,并结合有关热力学数据,算出它们的标准生成焓。并分析了它们的光电离解离通道及其随激发能量变化的竞争情况。     

二茂铁的同步辐射光电离

利用同步辐射和飞行时间质谱 ,研究了二茂铁的真空紫外光电离 ,得到了该分子的电离势为 (6 .78± 0 .0 5 )eV ,碎片离子FeC5H5+ 的出现势为 (13.4 0± 0 .10 )eV .根据实验结果 ,分析了二茂铁的主要光电离解离通道 ,估算了分子及离子的键解离能 .用密度泛涵的方法对该分子离子及一些主要的碎片离子进行了初步的量化计算 ,得到了二茂铁的电离势和一些碎片的出现势 .利用量化计算的数据还估算了分子及离子的键解离能 ,并与文献值进行了比较     

甲胺分子的紫外光解离动力学实验研究

在280—287.5 nm区域内,通过实验测定共振增强多光子电离-时间飞行质谱、碎片离子的分质量激发谱以及光强指数等对甲胺分子的光解离通道进行了研究.实验结果证实甲胺分子在单光子能量范围内存在一个电子排斥态,主要的光解离过程为甲胺分子共振吸收1个光子到达该电子排斥态后解离成中性碎片,然后是中性碎片经多光子共振电离形成碎片离子和碎片离子的进一步解离.     

噻吩和吡啶的同步辐射光电离解离

利用同步辐射产生的真空紫外光，研究了噻吩和吡啶的光电离解离过程，测定了它们的电离电势及其碎片离子的出现势；利用有关势力学数据，估算了某些离子的标准生成焓；分析了它们的紫光电离解离通道。在实验中还观测到噻吩和吡啶多聚体离子的存在，并讨论了它们的可能结构。     

甲胺分子的同步辐射光电离解离质谱

在超声射流冷却条件下,利用同步辐射光源,结合飞行时间质谱对CH3NH2分子在60—140nm波长范围内的光电离解离进行了研究.主要动力学过程为母体离子的解离过程.CH2NH2+和CH3+由CH3NH2+在高能量时解离生成,而CH2NH2+的1,1脱H2过程则产生其他离子.CH3NH2分子的电离势(IP)为916±001eV,和分子轨道能量计算的理论值符合得非常好,并获得CH3NH2+和CH2NH2+的生成热分别为860±05kJmol和7541kJmol. 关键词： 同步辐射光电离 飞行时间质谱 电离势 生成热     

Single-beam self-referenced phase-sensitive surface plasmon resonance sensor with high detection resolution

A versatile and low-cost single-beam self-referenced phase-sensitive surface plasmon resonance(SPR)sensing system with ultra-high resolution performance is presented.The system exhibits a root-mean-square phase fluctuation of ±0.0028.over a period of 45 min.i.e.a resolution of±5.2×10-9 refractive index units.The enhanced performance has been achieved through the incorporation of three design elements:a true single-beam configuration enabling complete self-referencing so that only the phase change associated with SPR gets detected,a differential measurement scheme to eliminate spurious signals not related to the sensor response,and the elimination of retardation drifts by incorporating temperature stabilization in the liquid crystal phase modulato .Our design should bring the detection sensitivity of non-labeling SPR biosensing closer to that achievable by conventional fluorescence-based techniques.     

Effect ofγ-radiation on the spectral luminescence characteristics of impure cadmium tungstate crystals

Results of a study of the effect of γ-radiation on the spectral luminescence properties of cadmium tungstate crystals doped with silver, bismuth, and molybdenum cations are presented. Spectral characteristics of the nondnnnoped crystals are briefly described. Absorption and photo and X-ray luminescence spectra of the crystals taken before and after exposure to γ-radiation (5.5·10⁴ Gy) are compared. It is found that the spectral characteristics of the crystals doped with silver, bismuth, and molybdenum cations do not change markedly after the exposure. The relation between the type of impurity-induced defects, individual characteristics of the impurity cations, and the character of the effect of γ-radiation on the spectral luminescence properties of impure crystals is analyzed (preliminarily). Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 64, No. 1, pp. 55–60, January–February, 1997.     

Cavitation in trees

Sap is transported under tension (i.e. negative pressure) in trees, according to the tension-cohesion theory. Since water is physically instable under negative pressure, a risk of cavitation is possible. Techniques have been developed during the past two decennia to study cavitation in trees. Trees appear remarkably immune to cavitation events. Cavities form only when extreme water stresses occur or when sap freezes. Nucleation is heterogeneous in trees, presumably caused by the aspiration of air bubbles through conduit walls. Threshold xylem pressures for cavitation vary greatly between species, in concordance with the great functional and ecological diversity of trees. To cite this article: H. Cochard, C. R. Physique 7 (2006).     

A stereo matching algorithm using multi-peak candidate matches and geometric constraints

Gray cross correlation matching technique is adopted to extract candidate matches with gray cross correla- tion coefficients less than some certain range of maximal correlation coefficient called multi-peak candidate matches. Multi-peak candidates are extracted corresponding to three closest feature points at first. The corresponding multi-peak candidate matches are used to construct the model polygon. Correspondence is determined based on the local geometric relations between the three feature points and the multi-peak candidates. The disparity test and the global consistency checkout are applied to eliminate the remaining ambiguous matches that are not removed by the local geometric relational test. Experimental results show that the proposed algorithm is feasible and accurate.     

Optical Pulse Compression Schemes That Use Nonlinear Bragg Gratings

Nonlinear optical pulse compression of picosecond pulses typically requires long lengths of optical fiber and multiple components. Periodic structures, such as fiber Bragg gratings, are highly dispersive at wavelengths outside of the photonic bandgap. This implies that such gratings can be used as very short all-fiber compressors. In this paper a number of such compression schemes are reviewed involving uniform and nonuniform fiber Bragg gratings, relying on both soliton and nonsoliton compression principles. Experimental results supporting the corresponding underlying theory are also presented. Finally, an extension of one of the compression schemes is shown, which allows the generation of adjustable high-repetition rate soliton trains.     

Conductively cooled all-solid-state zigzag slab laser

A diode pumped, Q-switched Nd：YAG zigzag slab laser is developed using passive conduction cooling. Flat-flat and unstable resonators are adopted in this experiment. The 150-mJ multi-mode and 100-mJ single-mode laser outputs with pulse width of 10 ns are achieved, corresponding to optical efficiencies of 19% and 13%, respectively. The experimental result demonstrates that the laser has the property of compact structure, high efficiency, reliability, and high beam quality. The design of laser has a potential application in space environment.     

The nature of empirical constants in the equation relating the frequency of the stretching vibration of oh-groups to parameters of the [MO n ]-polyhedrons coordinating these groups

Institute of Physicoorganic Chemistry, Academy of Sciences of Belarus, 220603, Minsk, Ul. Surganova, 13, Belarus. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 62, No. 1, pp. 104–107, January–February, 1995.     

Quantitative analysis results of CE-1 X-ray fluorescence spectrometer ground base experiment

As the nearest celestial body to the earth, the moon has become a hot spot again in astronomy field recently. The element analysis is a much important subject in many lunar projects. Remote X-ray spectrometry plays an important role in the geochemical exploration of the solar bodies. Because of th equasi-vacuum atmosphere on the moon, which has no absorption of X-ray, the X-ray fluorescence analysis is an effective way to determine the elemental abundance of lunar surface. The CE-1 X-ray fluorescence spectrometer (CE-1/XFS) aims to map the major elemental compositions on the lunar surface. This paper describes a method for quantitative analysis of elemental compositions. A series of ground base experiments are done to examine the capability of XFS. The obtained results, which show a reasonable agreement with the certified values at a 30% uncertainty level for major elements, are presented.     

Effect of oxygen on the optical properties of ZnSe in the region of 0.44–20 μm

Moscow Power Engineering Institute, 14, Krasnokazarmennaya Str., Moscow, GSP, 105835, Russia. Translated from Zhurnal Prikladnois Spektroskopii, Vol. 63, No. 4, pp. 646–651, July–August, 1996.     

Energy transfer as a method for investigation of the structure of electrolytes

S. I. Vavilov State Optical Institute, Russia, 199034, St. Peterburg, Birzhevaya Liniya, 12. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 62, No. 3, pp. 38–42, May–June, 1995.