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171.
M. Stangl V. Dittel J. Acker V. Hoffmann W. Gruner S. Strehle K. Wetzig 《Applied Surface Science》2005,252(1):158-161
At room temperature electroplated copper layers exhibit changes in resistivity, residual stress, and microstructure. This process, known as self-annealing, is intimately linked to the release of organic impurities, which stem from the incorporation of organic additives into the Cu layer in the course of the electroplating process. The behavior of these impurities during self-annealing, represented by the carbon content, could be detected by analytical radio frequency glow discharge optical emission spectrometry (GD-OES) and carrier gas hot extraction (CGHE). The precondition of a quantitative determination is a surface cleaning procedure to remove adsorbed organics from the copper surface. It was observed that at first almost all impurities have to leave the Cu metallization before an accelerated abnormal grain growth can start. The small amount of remaining organic species after self-annealing could be quantified by both examination techniques, GD-OES and CGHE. 相似文献
172.
The decomposition of perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA) molecules during evaporation of unpurified raw material in ultra high vacuum was studied. The fragments were identified by mass spectrometry and the influence of these fragments and further contaminations of the raw material on the electronic structure of PTCDA thin films was measured by photoemission spectroscopy. Annealing of contaminated PTCDA films was tested as cheap and easy to perform method for (partial) post deposition purification of the contaminated films. 相似文献
173.
A.F. Mesquita A.O. Porto G.M. de Lima J.M. Delgado F.S. Lameiras 《Solid State Communications》2005,136(3):133-137
Hexagonal and cubic cadmium selenide were prepared from a chemical route by using cadmium chloride and potassium selenium hydride obtained from reaction of selenium powder and potassium boron hydride. The product obtained was thermally treated under argon flux at 300, 500 and 600 °C for 2 h and characterized by X-ray photoelectron spectroscopy and X-ray diffraction. The X-ray diffraction data were refined by Rietveld method and the structural parameters were determined for the phases of each annealed samples. At 300 °C five phases were identified: Cubic and hexagonal cadmium selenides and the contaminants: Potassium chloride, boron oxide and cadmium boron oxide. At 500 and 600 °C only the hexagonal cadmium selenide phase was identified besides the other above mentioned contaminant. 相似文献
174.
Belov V. V. Dobrokhotov S. Yu. Maksimov V. A. 《Theoretical and Mathematical Physics》2003,135(3):765-791
Different versions of the Darboux–Weinstein theorem guarantee the existence of action–angle-type variables and the harmonic-oscillator variables in a neighborhood of isotropic tori in the phase space. The procedure for constructing these variables is reduced to solving a rather complicated system of partial differential equations. We show that this system can be integrated in quadratures, which permits reducing the problem of constructing these variables to solving a system of quadratic equations. We discuss several applications of this purely geometric fact in problems of classical and quantum mechanics. 相似文献
175.
李治明 《新疆大学学报(理工版)》2004,21(2):135-141,146
研究了具有开发的单种群非自治周期系统.利用非自治微分方程理论.以及变分法理论和泛函极值的Euler方程方法,得到了该开发系统的持续生存性.周期解存在性,全局渐近稳定性.研究了在开发情况下的最大收获量问题,以及取得最大经济效益下的收获问题等. 相似文献
176.
电子束流品质对自由电子激光小信号增益影响的计算 总被引:1,自引:0,他引:1
对电子束有一定初始能量分散或角度分散时的自由电子激光小信号增益用较简便的方法进行了分析计算,并给出了一个渐近公式,结果与用计算机模拟解自由电子激光微分方程组得到的结果一致。 相似文献
177.
S. Guizard D. Chapoulard M. Horani D. Gauyacq 《Applied physics. B, Lasers and optics》1989,48(6):471-477
Resonantly enhanced multiphoton ionization (REMPI) is proposed as an ultrasensitive detection method forreal-time monitoring of atmospheric pollutants in situ. The technique is demonstrated in the laboratory for NO diluted in pure nitrogen at 560 mbar. The MPI current resulting from (2+1) photon ionization of NO via the resonantC
2
H (v=0) state has been measured for several NO concentrations. Detection levels as low as 50 ppt have been obtained.Laboratoire associé à l'Université de Paris-Sud 相似文献
178.
Electron beam induced quantitative X-ray mapping has become a very useful characterisation tool for determining the elemental
distribution in materials, whether using energy dispersive spectroscopy or wavelength dispersive spectroscopy. The X-ray intensity
distributions of the elements from an X-ray map allow us to generate two dimensional and ternary scatter diagrams thus converting
spatial information into concentration dimensions, which is an important tool for displaying the spatial relationships of
elements or correlated elements (phases) in materials. To best understand how to use this tool, we need to understand the
production and features of the scatter diagram. The type of clustering observed in the scatter diagram, whether oval, linear
or spherical, can give the major and trace element distributions within phases as well as qualitative and quantitative phase
information. This paper demonstrates the generation of scatter diagrams, properties of scatter diagrams, interpretation of
scatter diagrams and the advantages of scatter diagrams through the use of examples. 相似文献
179.
The semi‐iterative method (SIM) is applied to the hyper‐power (HP) iteration, and necessary and sufficient conditions are given for the convergence of the semi‐iterative–hyper‐power (SIM–HP) iteration. The root convergence rate is computed for both the HP and SIM–HP methods, and the quotient convergence rate is given for the HP iteration. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
180.
Comprehensive studies of X-ray diffraction, oxygen content, superconductivity and Mössbauer effect have been made on FexCu1−xBa2YCu2O7+y superconductors (0.00≤x≤0.70) synthesized by ambient (AM) and high pressure (HP). Results indicate that all the HP-samples have tetragonal structure, smaller lattice parameter c and unit-cell volume than the AM-samples. The studies of oxygen content, and Mössbauer spectroscopy indicate that the HP-samples have higher oxygen content, carrier concentration and average valence of Fe than the AM-samples. Moreover, for the HP-samples more Fe atoms located in CuOx chains have fivefold-oxygen coordination. These are important reasons for the enhancement of Tc in the HP-samples. 相似文献