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991.
Recursion can generate a fractal limit set from a sequence of finite families of functions, even if every possible sequence does not converge to a limit point. Conditions, which make limit sets compact, are discussed. A construction giving an unbounded fractal is presented, together with an open question and an application of recursive compositions of contractions to sums of present values. 相似文献
992.
993.
Mats Erik Andersson 《Monatshefte für Mathematik》2002,134(3):177-190
The Poisson kernel over odd order cyclic groups and truncated to height two is studied for hypercontractivity. A relevant
multiplier inequality is verified. The corresponding convolution operator maps into with norm one for all parameters and all integers l.
(Received 26 April 2001) 相似文献
994.
Transfer ratios (i.e. the number of moles of the UV-absorbing probe anion displaced by one mole of analyte anion) were determined for the separation of inorganic and organic anions by capillary zone electrophoresis using indirect UV absorbance detection. When the electrolyte was buffered and contained only the probe anion and a single counter-cation, transfer ratios calculated from Kohlrausch theory were found to agree well with values obtained experimentally from accurately determined mobility data. However, these electrolyte systems gave long analysis times and were therefore considered impractical. More useful electrolytes were obtained by the addition of surfactants to suppress or reverse the electroosmotic flow but the co-anion introduced with the surfactant can reduce the value of the measured transfer ratio and hence adversely affect sensitivity. This problem was overcome by the use of a surfactant in the hydroxide from such as cetyltrimethylammonium hydroxide combined with a suitable buffering counter-cation such as protonated 1,3-bis[tris(hydroxymethyl)-methylamino]-propane or tris(hydroxymethyl)aminoethane. Four buffered electrolytes consisting of chromate, benzoate, phthalate, or trimellitate as probes and a suitable surfactant were used to determine transfer ratios. These systems were shown to give transfer ratios that were close to those calculated from Kohlrausch theory, thereby enabling prediction of experimental conditions giving maximum transfer ratios. 相似文献
995.
Anna Holmgren Thomas Gr?nstedt Bengt Andersson 《Reaction Kinetics and Catalysis Letters》1997,60(2):363-371
The flow distribution in a monolith is significantly improved by shaping the inlet face of the monolith to form a cone or
a parabola. The improved flow distribution results in a more efficient catalyst. 相似文献
996.
S. B. Andersson 《Applied physics. B, Lasers and optics》2005,80(7):809-816
We consider the problem of tracking a single fluorescent molecule in both two and three dimensions using a confocal laser scanning microscope. An estimate of the position of the molecule is generated from the measured fluorescence signal through the use of parameter estimation theory. This estimate is used in a nonlinear controller designed both to track the position of the molecule and to provide good measurements for use in the estimation algorithm. The performance of the approach is investigated through numerical simulation for molecules undergoing diffusion and directed transport and the capabilities of the controller relative to experimental limitations are discussed. 相似文献
997.
Mats Erik Andersson 《Proceedings of the American Mathematical Society》2005,133(5):1469-1473
It is shown that a Schur multiplier is compact if and only if it is the Schur product of two multipliers, one of which is a Hankel-Schur multiplier generated by an integrable function. This is illuminated by factoring exotic, singular measures and is brought into relation with Paley set-based multipliers.
998.
Magne Lygren Helge I. Andersson 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》2004,80(1):268-281
Large eddy simulations of the flow between a rotating
and a stationary disk have been performed using a dynamic and a
mixed dynamic subgrid-scale model. The simulations were compared
to direct numerical simulation results. The mixed dynamic model
gave better overall predictions than the dynamic model.
Modifications of the near-wall structures caused by the mean flow
three-dimensionality were also investigated. Conditional
averages near strong stress-producing events led to the same
conclusions regarding these modifications as studies of the flow
generated by direct numerical simulation, namely a distinct
asymmetry of the vortices producing sweeps and ejections. 相似文献
999.
1000.
60 polymerization in the temperature interval at pressures below by measurements of the time dependence of the thermal conductivity. It has been found at that the polymerization process at is slower than the reverse transformation from “polymeric” to “monomeric” phase at . The thermal conductivity of polymerized C60 was measured in the temperature range and found to increase with increasing temperature, which reflects strong phonon scattering. Both the presence of non-bonded
C60 molecules and a high degree of structural disorder in the crystalline lattice of the polymeric phase might be responsible
for the behaviour of . The results for are qualitatively similar to those reported previously for C60 polymerized at higher , but an order of magnitude smaller.
Received: 20 September 1996/Accepted: 11 November 1996 相似文献