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981.
Volker Weispfenning 《Algebra Universalis》1985,21(2-3):146-155
982.
983.
Ĺubor Fišera Volker Jäger Libuše Jarošková Juraj Kuban Vladimír Ondruš 《Chemistry of Heterocyclic Compounds》1995,31(10):1180-1182
The title reaction was investigated for both known achiral and new chiral optically pure nitrones. In all cases, formation of only two diastereomeric cycloadducts was observed.Department of Organic Chemistry, Slovak Technical University, 812 37 Bratislava, Slovak Republic. Department of Organic Chemistry, University of Stuttgart, D-70569 Stuttgart, Germany. Published in Khimiya Geterotsiklicheskikh Soedinenii No. 10, pp. 1350–1352. October, 1995. Original article submitted August 24, 1995. 相似文献
984.
985.
Volker R. Vosberg Michael G. Berger Werner Fischer Willem J. Quadakkers Hubertus Nickel 《Mikrochimica acta》1997,125(1-4):275-278
The effect of silicon and titanium on the spallation resistance of alumina scales grown on NiCrAlY-type alloys has been investigated. For this purpose cyclic oxidation experiments on model alloys with different additions of silicon or titanium were carried out at temperatures between 950 and 1100 °C. Selected samples were analysed by X-ray stress evaluation (XSE) after various times of oxidation. It was found that the compressive stresses measured at ambient temperature increase with increasing time and are affected by the presence of silicon. The XSE results were used to calibrate laser Raman spectroscopy (LRS) for strain measurement. Then, the suitability of Raman spectroscopy for stress measurement at higher temperatures was evaluated.Dedicated to Professor Dr. rer. nat. Dr. h.c. Hubertus Nickel on to occasion of his 65th birthday 相似文献
986.
987.
988.
F. Präßler Volker Hoffmann Joachim Schumann Klaus Wetzig 《Fresenius' Journal of Analytical Chemistry》1996,355(7-8):840-846
An algorithm is presented as a concept for the quantification in direct current and radiofrequency glow discharge (GD) modes for GD optical emission spectroscopy. The algorithm is divided into excitation and sputtering part and thus it is possible to distinguish between the different excitation processes and to consider equivalent sputtering crater formations in both modes. Intensity-time profiles are affected corresponding to the method by several effects. One important effect is that sputtering occurs at a single time in different depths because of curved crater bottoms, this is usually called crater effect. The main purpose is to introduce an iterative deconvolution technique which for the quantification numerically takes into account the curved sputtering crater bottom. Input data for the deconvolution technique are the calibrated mass-time profile, the partial densities of the sample constituents and the measured final shape of the sputtering crater. Using a relatively simple model for ion sputtering the deconvolution technique improves iteratively the calculated layer structure by means of information on crater formation. The mathematical handling is illustrated for the quantification of a depth profile of a multilayer sample of ten 100 nm layers. The resulting concentration-depth profile reflects excellently the real elemental distribution of the multilayer system. 相似文献
989.
Consider a ring on which customers arrive according to a Poisson process. Arriving customers drop somewhere on the circle and wait there for a server who travels on the ring. Whenever this server encounters a customer, he stops and serves the customer according to an arbitrary service time distribution. After the service is completed, the server removes the client from the circle and resumes his journey.We are interested in the number and the locations of customers that are waiting for service. These locations are modeled as random counting measures on the circle. Two different types of servers are considered: The polling server and the Brownian (or drunken) server. It is shown that under both server motions the system is stable if the traffic intensity is less than 1. Furthermore, several earlier results on the configuration of waiting customers are extended, by combining results from random measure theory, stochastic integration and renewal theory. 相似文献
990.