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31.
Andreas Wallner Margit Hölbling Judith Baumgartner Christoph Marschner 《Silicon Chemistry》2007,3(3-4):175-185
A number of cyclo-and bicyclosilanes have been prepared and structurally characterized by X-ray crystallography and Raman
spectroscopy. 1,1,4,4- and 1,1,3,3-tetrakis(trimethylsilyl)octamethylcyclohexasilanes were found to exhibit unusual twist- and twisted boat-conformations. The UV absorption properties of all compounds were studied and found to show absorption maxima red shifted
compared to the parent compound dodecamethylcyclohexasilane.
Dedicated to Prof. Mitsuo Kira on the occasion of his reception of the Wacker Silicon Award 2005 and in recongnition of his
numerous outstanding achievements in organosilicon chemistry. 相似文献
32.
Andreas E. Schroth 《Journal of Geometry》1991,42(1-2):141-147
The number of circles of a flat Laguerre plane touching three given circles or points depends only on the given geometric configuration but not on the Laguerre plane.Dedicated to Prof. J. Joussen on his 60th birthday 相似文献
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Lufthansa Technical Training GmbH (LTT) performs training courses for Lufthansa Technik AG as well as for several other international airlines. Courses of about 670 different types are offered of which several hundred take place each year. The course scheduling problem faced by LTT is to construct a yearly schedule which maximizes the profit margin incurred while meeting a variety of complex precedence, temporal, and resource-related constraints. A “good” operational schedule should also meet a number of additional subordinate objectives. We formalize the problem and develop a heuristic scheme along with several priority rules, as well as a local search algorithm to determine well-suited weights for weighted composite rules. The operational planning situation of 1996 served as our major test instance; additional test instances were constructed by modifying this data. Several computational experiments were carried out to evaluate the performance of the algorithms. It turned out that the best so-found schedule is substantially better in terms of the profit margin incurred than the solution manually constructed by LTT. 相似文献
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Andreas Maurer 《Letters in Mathematical Physics》1990,20(1):55-63
The method of infrared bounds is extended to a large class of nearest neighbour interactions in classical spin systems. Temperature controlled bounds on fluctuations follow whenever the coupling function is a positive definite kernel. Existence of phase transitions is demonstrated for the RP
Nmodel for d3. 相似文献
39.
Andreas Floer 《Communications in Mathematical Physics》1988,118(2):215-240
To an oriented closed 3-dimensional manifoldM withH
1(M, )=0, we assign a 8-graded homology groupI
*(M) whose Euler characteristic is twice Casson's invariant. The definition uses a construction on the space of instantons onM×. 相似文献
40.
It is shown that the time-dependent WKB expansion highlights some of the hidden properties of the Schrödinger equation and forms a natural bridge between that equation and the functional integral formulation of quantum mechanics. In particular it is shown that the leading (zero- and first-order in ) terms in the WKB expansion are essentially classical, and the relationship of this result to the classical nature of the WKB partition function, and of the anomalies in quantum field theory, is discussed. 相似文献