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121.
Summary We prove that a
d
-action by automorphisms of a compact, abelian group is Bernoulli if and only if it has completely positive entropy. The key ingredients of the proof are the extension of certain notions of asymptotic block independence from -actions to
d
-action and their equivalence with Bernoullicity, and a surprisingly close link between one of these asymptotic block independence properties for
d
-actions by automorphisms of compact, abelian groups and the product formula for valuations on global fields.Oblatum 20-X-1994 相似文献
122.
Klaus Doerffel 《Fresenius' Journal of Analytical Chemistry》1994,349(8-9):578-581
Noisy analytical data dependent on 2 different variables (bivariate data) can be evaluated by an extended (2-dimensional) CUSUM-algorithm. Even at very high random fluctuations this 2d-CUSUM allows to detect long-term instationarities even from short series of measurements. The model of 2d-CUSUM as well as examples (distribution analysis, time-series analysis, treatment of calibration functions) are shown in this paper.Dedicated to Professor Dr. R. Geyer (Naumburg/Saale) on the occasion of his 80th birthday on April 14, 1994 相似文献
123.
Klaus Deimling Paul Szilágyi 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》1994,45(1):53-60
Dry friction problems lead to discontinuous differential equations, e.g. to
相似文献
124.
Michael Meyberg Elvezio Morenzoni Thomas Wutzke Uwe Zimmermann Franz Kottmann Klaus Jungmann Björn Matthias Thomas Prokscha 《Hyperfine Interactions》1994,87(1):1075-1081
At PSI we are investigating the technique of decelerating an existing very intense secondary beam of surface
+ (4 MeV) to an energy of 10 eV using appropriate moderators. These
+ can then be used as a source of a tertiary beam of low energy muons with tunable kinetic energy between 10 eV and 10 keV.With a 1000 A layer of solid Argon deposited on an Al substrate we obtain a moderation efficiency (with respect to the number of incoming surface
+) of the order of 10–4.Results of our investigations and the present status of the project are presented together with future plans and possibilities. 相似文献
125.
Volkmar Nejedl Michael Panzner Stefan Baunack Ulrich Franz Arnold Luft Klaus Wetzig 《Mikrochimica acta》1998,130(1-2):89-95
The laser induced modification of iron surfaces with atmospheric species was investigated by means of Auger electron spectroscopy (AES) and scanning electron microscopy (SEM). Different laser systems were used for irradiating iron samples in a wide range of the laser processing parameters up to small foci and ultra short pulses.A nitriding of iron connected with an oxidation of the near surface region was observed in the wavelength range between 193 nm and 10.6 m using large foci (0.1 cm2) and short pulses (10...1400ns). In case of small foci (7·10–6cm2) with ns-pulses (50 ns) an enrichment of the iron melt with nitrogen and an advanced oxidation of the surrounding area of the laser spot were detected. When using shorter pulses (200 fs, 40 ps) no indications for a nitriding were found. 相似文献
126.
127.
Summary We prove that every mixing
d
by automorphisms of a compact, connected, abelian group is mixing of all orders.Oblatum 5-II-1992The second author gratefully acknowledges support from NSF grant DMS-91-03056 at the Ohio State University 相似文献
128.
We show that a maximal partial spread inPG(3,q) is either a spread or has at most
lines. This implies that it is not possible to cover all points but the points of a Baer-subspace by lines. 相似文献
129.
A variable concept for the synthesis of branched glycosyl phosphatidyl inositol (GPI) anchors was established. Its efficiency could be shown by the successful synthesis of the GPI anchor of rat brain Thy-1 and of the scrapie prion protein both in the water soluble 1c and lipidated form 1a. Retrosynthesis led to building blocks 2-6 of which 5 could be further disconnected to building blocks 7-9. Trichloroacetimidate 5 was built up in a straightforward manner starting from glycosyl acceptor 9 using known glycosyl donors 7 and 8. The carbohydrate backbone was then assembled by glycosylation of pseudodisaccharide acceptor 6 with donor 5. To ensure high stereoselectivity and good yields in the glycosylation reactions, anchimeric assistance was employed. Successive deprotection and introduction of the various phosphate residues gave the fully protected GPI anchors. Catalytic hydrogenation and acid-catalyzed cleavage of the Boc protecting groups afforded the target molecules, which could be fully structurally assigned. 相似文献
130.
Klaus Rose Vlastimil MatĚjec Milos Hayer Marie PospiŠilovÁ 《Journal of Sol-Gel Science and Technology》1998,13(1-3):729-733
Various types of UV-curable organically modified siloxanes have been synthesized by the sol-gel method with the aim of fabricating chemically sensitive coatings for silica optical fibers. The refractive index of the coating material can be tailored in the range from 1.46 to 1.56 and sensitivity towards CO2 is achieved by incorporation of amino groups. The interaction of the cured layers with CO2 or with hydrocarbons has been studied in immersion experiments. Both the reaction of CO2 with incorporated amino groups and the penetration of hydrocarbons into the layer induce changes of the light absorption coefficient and the refractive index of the coating which are detected by measuring the output light intensity from the fiber. 相似文献
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