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41.
42.
The variation of certain lines of diffraction of the substrate, when adsorption takes place, can give information on the position of the adsorbate relative to the substrate and its degree of registry. This variation is altered by stacking faults in the substrate. A calculation of these variations, which takes account of the above faults, is presented. It is shown that when stacking faults are few a good approximation can be obtained by considering perfect crystallites, but the exact allotropie variety depends upon the line examined. 相似文献
43.
Amine- and phosphine-boryl radicals add to 2-methyl-2-nitrosopropane, 2,4,6-tri-t-butylnitrosobenzene, and phenyl-N-t-butylnitrone to give nitroxide spin-adducts and the application of these spin-trapping reactions as mechanistic probes is described. 相似文献
44.
J. T. Marti 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》1971,22(5):991-996
Zusammenfassung Für eine sehr allgemeine Klasse von Funktionen, die eine kompakte TeilmengeX eines BanachraumesE stetig inE abbilden, wird gezeigt, dass sich jede dieser Funktionen aufX beliebig genau gleichmässig durch entartete Polynomoperatoren approximieren lässt. 相似文献
45.
Quantitative data for some of the radionuclides, most important because of their intensity and radiotoxicity, present in the biosphere after the Chernobyl accident are given for a selected number among numerous plant and food samples analyzed before and after the accident. 相似文献
46.
The trend of variation of sediment radiocontamination, expressed as a function of space and time, and specific accumulation of particular radionuclides in some investigated localities, are discussed on the basis of experimental results of gamma spectrometric analyses of artificial radionuclide contents. 相似文献
47.
48.
Albino Polcari Marc Dhall Frank Marti Grgoire Witz Yibing Huang Ren Flükiger 《Physica C: Superconductivity and its Applications》1998,310(1-4):177-181
AC losses in multifilamentary tapes depend on various parameters. Among them, geometrical factors such as overall tape width and thickness as well as the precise arrangement of the filaments are expected to have an important influence. Several theoretical models describe this dependency. In order to study these geometrical effects experimentally, we prepared a series of Bi(2223)/Ag tapes with gradually changing filament arrangements and tape aspect ratio, and characterised them by AC transport and magnetic measurements. The results are compared to model predictions. 相似文献
49.
NURBS (Non-Uniform Rational B-Splines) belong to special approximation curves and surfaces which are described by control
points with weights and B-spline basis functions. They are often used in modern areas of computer graphics as free-form modelling,
modelling of processes. In literature, NURBS surfaces are often called tensor product surfaces. In this article we try to
explain the relationship between the classic algebraic point of view and the practical geometrical application on NURBS. 相似文献
50.
K. Marti A. Aurnhammer 《Mathematical and Computer Modelling of Dynamical Systems: Methods, Tools and Applications in Engineering and Related Sciences》2013,19(1):75-116
In the optimal control of industrial, field or service robots, the standard procedure is to determine first offline a reference trajectory and a feedforward control, based on some selected nominal values of the unknown stochastic model parameters, and to correct then the inevitable and increasing deviation of the state or performance of the robot from the prescribed state or performance of the system by online measurement and control actions. Due to the stochastic variations of the model parameters, increasing measurement and correction actions are needed during the process. By optimal stochastic trajectory planning (OSTP), based on stochastic optimization methods, the available a priori and sample information about the robot and its working environment is incorporated into the control process. Consequently, more robust reference trajectories and feedforward controls are obtained which cause much less online control actions. In order to maintain a high quality of the guiding functions, the reference trajectory and the feedforward control can be updated at some later time points such that additional information about the control process is available. After the presentation of the Adaptive Optimal Stochastic Trajectory Planning (AOSTP) procedure based on stochastic optimization methods, several numerical techniques for the computation of robust reference trajectories and feedforward controls under real-time conditions are presented. Additionally, numerical examples for a Manutec r3 industrial robot are discussed. The first one demonstrates real-time solutions of (OSTP) based on a sensitivity analysis of a before-hand calculated reference trajectory. The second shows the differences between reference trajectories based on deterministic methods and the stochastic methods introduced in this paper. Based on simulations of the robots behavior, the increased robustness of stochastic reference trajectories is demonstrated. 相似文献