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991.
In this paper we study a class of separable Banach spaces which can be approximated by certain special finite-dimensional
subspaces. This class is characterized in Theorem 1.1, from which it follows that the space of continuous scalar-valued functions
on a compact metric space always belongs to this class, and that every member of this class has a monotone basis.
Supported in part by N.S.F. Grant 11-5020.
Supported in part by N.S.F. Grant GP-3579. 相似文献
992.
Jan Epsztajn Zbigniew Berski Jacek Z. Brzeziński Andrzej Jóźwiak 《Tetrahedron letters》1980,21(49):4739-4742
The behaviour of the N,N-dimethyl-, N,N-diethyl- and N,N-diisopropylpyridylcarboxylic amides in the reactions with Et2NLi and iPr2NLi, and a convenient way of synthesis of 2,3- and 3,4-disubstituted pyridines, by the direct lithiation of N,N-diisopropylamides leading subsequently to the ortho new CC bonds formation, are described. 相似文献
993.
The influence of fuzzy implication operators and the connective Also on the accuracy of a fuzzy model of a d.c. series motor is considered. Some typical fuzzy implication operators are applied to the construction of a fuzzy model of a d.c. series motor. A root-mean-square error is used as the criterion of the fuzzy model's adequacy to the real system. A number of mathematical operations necessary for the implementation of the fuzzy model are used as the criterion by which the fuzzy model's applicability if estimated from the point of view of computing techniques. The best types of fuzzy relations, representing fuzzy models of a real system, are chosen in order to secure the least root-mean-square error with minimal number of mathematical operations necessary for computer implementation. 相似文献
994.
Witold Mozgawa 《Rendiconti del Circolo Matematico di Palermo》1985,34(2):192-201
There is proved that the transgressed classes are invariant under holomorphically projective transformations of connections. 相似文献
995.
This paper deals with some problems of the control of fuzzy systems described by means of a relational equation of the type: Xκ + 1 = Uκ ° Xκ ° R. The basic aspects such as mutual identification and control, stabilization control, control with constraints, generation of control rules of a fuzzy logic controller, important from the theoretical and applicational point of view are discussed and illustrated by means of numerical examples. 相似文献
996.
An attempt is made to develop the expression for surface excess, in adsorption of binary ideal mixtures on patchwise heterogeneous surfaces. The distribution of adsorption energies is evaluated for an adsorption system, investigated experimentally and theoretically by Sircar and Mayers. 相似文献
997.
M. Spaliński 《Zeitschrift fur Physik C Particles and Fields》1988,41(1):87-90
The leading non analytic chiral corrections to the mass of the invisible axion and to the parameters describing its mixing with the pion and the eta are calculated. It is found that these corrections are much smaller than expected on the basis of order of magnitude estimates. The correction to the decay width into two photons is also found to be negligible. 相似文献
998.
999.
We discuss several concepts of continuity, weaker than lower semicontinuity, but still implying the existence of a continuous selection for a closed convex valued multifunction from a paracompact Hausdorff topological space into a Banach space. In this way, an extension of Michael's celebrated selection theorem is given. The behavior of -envelop approximations, as well as the localization of continuous selections, is also discussed. 相似文献
1000.
On the basis of the experimental results described in detail in the following sections an explanation of the mechanism of liquid modifier in chalk filled PP action was proposed. After concluding that liquid modifier does not change the sample morphology and crystallinity it was stated that it facilitates filler particles translocation in polymer matrix during deformation. Such translocations are the necessary condition for saturation of volume increase of the sample due to void formation in the process of polymer filler separation preserving the sample from its premature fracture. The most important physicochemical parameter of liquid modifier seems to be its molecular weight. This parameter determines liquids ability to migrate in micropore structure arising under stress and thus to act as a cracking agent. The possibility of the importance of more efficient heat dissipation in the sample was shown indicating the role of better thermal contacts in the sample in the case of modified chalk used as a filler. Such picture of mechanism of liquid modifier action leads also to two important conclusions: Due to polymer filler separation by means of liquid layer no further filler particles surface processing, as in some cases, is needed. The method of modification can be easily generalized for other polymers especially other polyolefins [19], [20] as physicochemical requirements for liquid are known. 相似文献