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排序方式: 共有344条查询结果,搜索用时 15 毫秒
341.
Salih Jawad 《Results in Mathematics》2016,70(1-2):197-208
In this paper we present new and generalized results on the differentiability of the parameter integral, in abstract spaces as well. 相似文献
342.
A. P. Yal’ch I. E. Mitropol’skii V. S. Buksar L. M. Markovich S. S. Pop 《Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques》2008,2(4):577-581
The characteristics of optical radiation produced under bombardment by ions (1–15 keV) and electrons (100–1000 eV) of a ruby surface are studied. Two broad bands with maxima at 330 and 450 nm attributed to defects of the crystal lattice are discovered in the spectral region of 200 to 800 nm. Characteristic radiation related to radiative relaxation of excited Cr3+ ions in the near-surface region of the crystal is observed. The dependence of the radiation intensity on the energy and current density of the bombarding particles is obtained experimentally. The degree of radiation polarization is determined. 相似文献
343.
C. Yalçın Kaya 《Computational Optimization and Applications》2017,68(3):719-747
Markov–Dubins path is the shortest planar curve joining two points with prescribed tangents, with a specified bound on its curvature. Its structure, as proved by Dubins in 1957, nearly 70 years after Markov posed the problem of finding it, is elegantly simple: a selection of at most three arcs are concatenated, each of which is either a circular arc of maximum (prescribed) curvature or a straight line. The Markov–Dubins problem and its variants have since been extensively studied in practical and theoretical settings. A reformulation of the Markov–Dubins problem as an optimal control problem was subsequently studied by various researchers using the Pontryagin maximum principle and additional techniques, to reproduce Dubins’ result. In the present paper, we study the same reformulation, and apply the maximum principle, with new insights, to derive Dubins’ result again. We prove that abnormal control solutions do exist. We characterize these solutions, which were not studied adequately in the literature previously, as a concatenation of at most two circular arcs and show that they are also solutions of the normal problem. Moreover, we prove that any feasible path of the types mentioned in Dubins’ result is a stationary solution, i.e., that it satisfies the Pontryagin maximum principle. We propose a numerical method for computing Markov–Dubins path. We illustrate the theory and the numerical approach by three qualitatively different examples. 相似文献
344.
We have developed a novel approach to obtain high metal sorption capacity utilizing a membrane containing chitosan and an immobilized reactive dye (i.e. Reactive Yellow-2). The composite membrane was characterized by SEM, FT-IR, swelling test, and elemental analysis. The membrane has uniform small pores distribution and the pore dimensions are between 5 and 10 μm, and the HEMA:chitosan ratio was 50:1. The reactive dye immobilized composite membrane was used in the removal of heavy metal ions [i.e., Pb(II), Hg(II) and Cd(II)] from aqueous medium containing different amounts of these ions (5-600 mg l−1) and at different pH values (2.0-7.0). The maximum adsorption capacities of heavy metal ions onto the composite membrane under non-competitive conditions were 64.3 mmol m−2 for Pb(II), 52.7 mmol m−2 for Hg(II), 39.6 mmol m−2 for Cd(II) and the affinity order was Pb(II) > Hg(II)>Cd(II). 相似文献