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381.
The 1H, 13C and 29Si nuclear magnetic resonance spectra of the parent compound and twelve derivatives of 2,8,9-trioxa-5-aza-1-silatricyclo[3.3.3.01,5]undecane (silatrane) are discussed. Effective Taft polarity constants for the silatrane substituents are proposed. An equation is developed to correlate the 29Si NMR chemical shifts of the silatranes with the corresponding organo-triethoxysilanes. 相似文献
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We consider the problem of finding a maximum-weight complementary basis of anm × 2m matrix. The problem arises naturally, for example, when a complementary set of columns is proposed as an initial basis for a warm start of Lemke's algorithm, but the set of columns is rank-deficient. We show that the problem is a special case of the problem of finding a maximum-weight common base of two matroids. Furthermore, we show how to efficiently implement an algorithm for the general problem in the present context. Finally, we give computational results demonstrating the practicality of our algorithm in a typical application.Supported by the Canadian Natural Science and Engineering Research Council. 相似文献
387.
Jonathan M. Borwein Jon D. Vanderwerff 《Transactions of the American Mathematical Society》1996,348(4):1617-1631
We examine when a sequence of lsc convex functions on a Banach space converges uniformly on bounded sets (resp. compact sets) provided it converges Attouch-Wets (resp. Painlevé-Kuratowski). We also obtain related results for pointwise convergence and uniform convergence on weakly compact sets. Some known results concerning the convergence of sequences of linear functionals are shown to also hold for lsc convex functions. For example, a sequence of lsc convex functions converges uniformly on bounded sets to a continuous affine function provided that the convergence is uniform on weakly compact sets and the space does not contain an isomorphic copy of .
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Wright J 《Chaos (Woodbury, N.Y.)》1995,5(2):356-366
We extend our method for classifying signals from chaotic nonlinear dynamical systems to the problem of monitoring chaotic nonlinear dynamical systems with the goal of detecting that the state of a system has changed. One potential application would be to systems where the changes are not easily detectable by spectral analysis or other linear techniques. The method is expected to be most useful in comparison to other techniques when there are other signals or noise present, some of which have a broad band frequency spectrum, and the signal of interest is associated with either a low dimensional dynamical system or a low dimensional chaotic attractor. The method is applied to data from a laboratory model of a fluidized bed reactor and to data from a gyroscope as well as to numerically generated signals from mathematical models. For the dynamical systems considered in the paper, the proposed method provides significantly better discrimination than spectral analysis. (c) 1995 American Institute of Physics. 相似文献
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Metalation of the methyl group in the title compound is accomplished through the open chain Cornforth precursor. This technique is necessary due to the preferred metalation of the 5-H proton in oxazoles. 相似文献