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Patrick Mather Nino Grizzuti Glenn Heffner Mathias Ricker Willie E. Rochefort Markus Seitz Hans-Werner Schmidt Dale S. Pearson 《Liquid crystals》1994,17(6):811-826
In this paper, we report on the synthesis and detailed characterization of a new semiflexible nematic liquid crystalline polyester which could serve as a 'model' polyester for a variety of physical and physico-chemical investigations. The polymer is a nematic liquid over a wide temperature range-from the glass transition temperature at ∼95°C to the isotropic transition at ∼240°C. We expect this polyester to be particularly useful for studying the effect of flow on the orientation of liquid crystalline polymers, as well as the production and removal of disclinations. 相似文献
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In this paper, we outline the use of relational control structures (Regel-Relative) to describe continuous-time linear systems and show how well known time-invariance from control theory can be defined by these algebraic structures. Furthermore, such important system properties as controllability and reachability are introduced to arbitrary (nonlinear, non-smooth, discontinuous) dynamical systems. 相似文献
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Marko D. Mihovilovic Bernhard Müller Markus Spina Arjumand I. Durrani Peter Stanetty Georg Dazinger Karl Kirchner 《Monatshefte für Chemie / Chemical Monthly》2006,137(6):785-794
Summary. Recombinant Escherichia coli overexpressing Pseudomonas sp. NCIMB 9872 cyclopentanone monooxygenase (CPMO, EC 1.14.13.16) and Acinetobacter sp. NCIMB 9871 cyclohexanone monooxygenase (CHMO, EC 1.14.13.22) have been utilized in whole-cell Baeyer-Villiger biotransformations of prochiral bicycloketones. A significant difference in substrate acceptance and stereoselectivity was
observed for bicyclo[3.3.0] and bicyclo[4.3.0] substrates. A plausible mechanism of these transformations was established
by means of high level DFT/B3LYP calculations suggesting an essential difference in electronic requirements for a successful
enzymatic conversion, which was similarly encountered in recombinant whole-cell mediated biooxidations. Some of the lactones
produced in the biocatalytic Baeyer-Villiger oxidation represent key intermediates for the synthesis of indole alkaloids. 相似文献
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Kazhdan constants relative to conjugacy classes of compact groups are computed. They depend on the nontrivial irreducible characters of the respective group. The result is applied, in particular, to finite groups of Lie type, symmetric groups, and the group SU(n). 相似文献
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Markus Kirkilionis 《Journal of Mathematical Analysis and Applications》2004,299(1):157-173
We state and prove general comparison principles for ordinary differential equations, discuss the scope of these principles, and present examples. 相似文献
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Daniel E. Vogler Ana Lorencak Julien M. Rey Markus W. Sigrist 《Optics and Lasers in Engineering》2005,43(3-5):527
A novel sensitive technique for the determination of losses in fiber cavities is presented. The method is based on the cavity ringdown scheme implemented in silica-based single-mode fibers. Bending losses of fiber cavities of different lengths have been measured showing all an oscillating behavior with respect to the curvature radius of the fiber as predicted by a theoretical model. The best minimum detectable absorbance per cavity pass achieved by this new method is 1.72×10−3 dB within a 10 m-long cavity. This limit suffices well for an accurate determination of optical bending losses even in bend-insensitive fibers. Furthermore, the comparison of the measured bending losses with a theoretical model allows the extraction of different fiber parameters. Good agreement has been found between the experimentally derived parameters and literature data. 相似文献