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排序方式: 共有1311条查询结果,搜索用时 15 毫秒
1.
Jeroen J. L. M. Cornelissen W. Sander Graswinckel Alan E. Rowan Nico A. J. M. Sommerdijk Roeland J. M. Nolte 《Journal of polymer science. Part A, Polymer chemistry》2003,41(11):1725-1736
The conformational properties of polymers derived from isocyanodipeptides have been investigated with a combination of model calculations, X‐ray diffraction, and circular dichroism spectroscopy. Depending on the configuration of the side chains, defined arrays of hydrogen bonds along the polymeric backbone are formed. This leads to a well‐defined conformation as, for example, expressed in the formation of lyotropic liquid‐crystalline phases and increased helical stability. Upon the disruption of the hydrogen bonds by a strong acid, a less well‐defined macromolecular conformation is observed. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 1725–1736, 2003 相似文献
2.
Sylvia Pulmannová 《International Journal of Theoretical Physics》2004,43(7-8):1573-1585
Divisible effect algebras and their relations to convex effect algebras and MV-algebras are studied. A categorical equivalence between divisible effect algebras and rational vector spaces is proved. Infinitesimal, sharp and extremal elements in divisible effect algebras are studied and their relations to properties of the state space are shown. 相似文献
3.
Sylvia Pulmannová 《International Journal of Theoretical Physics》2003,42(5):907-919
Tensor products of quantum logics and effect algebras with some known problems are reviewed. It is noticed that although tensor products of effect algebras having at least one state exist, in the category of complex Hilbert space effect algebras similar problems as with tensor products of projection lattices occur. Nevertheless, if one of the two coupled physical systems is classical, tensor product exists and can be considered as a Boolean power. Some applications of tensor products (in the form of Boolean powers) to quantum measurements are reviewed. 相似文献
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Application of graph-theoretic methods to new perimeter polynomials for connected clusters on a lattice yields extra data on the total number of clusters and for the coefficients in the series expansion for the mean size of clusters at low densities. The lattices studied are the square, the square with next nearest neighbors, the triangular, and the simple cubic. 相似文献
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Ohne ZusammenfassungD 21.Die vorstehende Arbeit wurde auf Anregung und unter Leitung von Herrn Professor Dr. Wöhlisch ausgeführt. 相似文献
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Sander C. Hille 《Integral Equations and Operator Theory》2005,53(4):597-601
A linear semigroup in a Banach space induces a linear semigroup on a Banach space that can be continuously embedded in the
former such that its image is invariant. This restriction need not be strongly continuous, although the original semigroup
is strongly continuous. We show that norm or weak compactness of partial orbits is a necessary and sufficient condition for
strong continuity of the restriction of a C0-semigroup. We then show that if the embedded Banach space is reflexive and the norms of the restricted semigroup operators
are bounded near the initial time, then the restricted semigroup is strongly continuous. 相似文献
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