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51.
D. Schild R. Pflaum G. Riefer E. Recknagel 《Zeitschrift für Physik D Atoms, Molecules and Clusters》1989,12(1-4):235-236
Compound cluster ions of heavy post-transition atoms (In, Pb, As, Sb, Bi) are enriched by electron induced dissociation if they are analogous to the Zintl polyanions Pb 5 2? and Pb 9 4? with respect to the atom and valence electron number. 相似文献
52.
The reactivity of the tridentate organic ligand, 2,3,5,6-tetrakis-(2'-pyridyl)-pyrazine, toward hydrogen ion and transition metal ions was investigated. The purple color of the bis-2,3,5,6-tetra-(2'-pyridyl)-pyrazine-iron(II) complex can be used in a colorimetric method for iron(II). The complex in aqueous solution exhibits a wavelength of maximum absorption at 575 mμ and a molar absorptivity of 19,800 in the pH range of 3.0–7.0. Beer's law is obeyed over the concentration range 5.0–100· 10-6M. The perchlorate salt of the complex is extractable into chloroform and nitrobenzene with absorption maxima of 570 mμ and 573 mμ and molar absorptivities of 19,200 and 17,400, respectively. The effects of diverse ions and the results of determinations on selected samples are discussed. 相似文献
53.
Sodium halide clusters are generated by inert gas condensation and probed by electron and photon induced dissociation. The dependence of fragmentation on electron energy and initial cluster temperature indicates a direct electronic fragmentation process without an intermediate state of vibrationally hot clusters. 相似文献
54.
The room-temperature phosphorescence of indole and thirteen substituted indoles on Schleicher and Schüll 2040A filter paper is reported. Caesium and iodide ions are effective in increasing the emission intensity. In the presence of iodide, the excitation and emission wavelengths of indole are 279 and 440 nm respectively. The excitation and emission wavelengths of indoles with aliphatic groups in the 3-position are 288-289 and 443-449 nm respectively. Indoles with 3,5-substitution have excitation and emission wavelengths of 300-308 and 448-460 nm respectively. Indoxylsulphate and indoxyl-beta-d-glucoside were the only indoles surveyed for which variations in the excitation and emission wavelengths depended on the heavy-atom ion present. These compounds had excitation wavelengths ranging from 288 to 388 nm, depending on which heavy-atom perturber was used. Emission wavelengths were 460-500 nm. Log-log plots of intensity vs. concentration were linear between 0.05 and 700 microg/ml for all the compounds studied, with detection limits in the nanogram range. 相似文献
55.
Markus J. Pflaum 《Communications in Mathematical Physics》1994,166(2):279-315
It is shown that the principle of locality and noncommutative geometry can be connected by a sheaf theoretical method. In this framework quantum spaces are introduced and examples in mathematical physics are given. Within the language of quantum spaces noncommutative principal and vector bundles are defined and their properties are studied. Important constructions in the classical theory of principal fibre bundles like associated bundles and differential calculi are carried over to the quantum case. At the endq-deformed instanton models are introduced for every integral index. 相似文献
56.
Maximilian Nothaft Steffen Höhla Dr. Aurélien Nicolet Prof. Dr. Fedor Jelezko Prof. Dr. Norbert Frühauf Prof. Dr. Jens Pflaum Prof. Dr. Jörg Wrachtrup 《Chemphyschem》2011,12(14):2590-2595
Photoluminescence quenching of single dibenzoterrylene (DBT) dye molecules in a polymeric organic light‐emitting diode was utilized to analyze the current dynamics at nanometer resolution. The quenching mechanism of single DBT molecules results from an increase in the triplet‐state population induced by charge carrier recombination on individual guest molecules. As a consequence of the long triplet‐state relaxation time, its population results in a reduced photoluminescence of the dispersed fluorescent dyes. From the decrease in photoluminescence together with photon correlation measurements, we could quantify the local current density and its time‐dependent evolution in the vicinity of the single‐molecule probe. This optical technique establishes a non‐invasive approach to map the time‐resolved current density in organic light‐emitting diodes on the nanometer scale. 相似文献
57.
Q-switching is considered as a favorable technology to generate short duration and high peak power pulses, which is widely used in industry. We derive a new model to simulate passively Q-switched solid state lasers in a three-dimensional (3D) space. In our model, several Gaussian modes are considered. Compared with single-mode models, 3D multimode models are much more capable of reflecting laser behaviors. In our modeling, the single-mode system is extended to a multimode system, which calculates photon numbers for different modes separately. In order to realize the numerical simulation of our multimode model, we apply a finite volume discretization respectively to the gain medium and saturable absorber, then the discretized multimode passively Q-switched laser system is obtained. The numerical results and applications of our model are shown at the end of the paper. The modeling and simulation of passively Q-switched solid state lasers can help to optimize laser designs. 相似文献