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991.
Stefano A. Mezzasalma 《Journal of statistical physics》2001,102(5-6):1331-1341
The Bolyai–Lobachevskij (BL) formula, relating parallelism angle and distance in a Non-Euclidean space, is used to introduce a geometrical partition function. Employing a correspondence between Boltzmann factor and BL characteristic length, allows us to get a simple relation for average size and space curvature, which is the analogy to the equation for the mean energy derived from the ordinary partition function. Due to the equivalence, recently proposed, between a chain molecule in a liquid and a geodesic path in a relativistic space, the equation obtained is expected to be suitable for describing geometrical phenomena in polymer-like networks. Simple applications to swelling of polymer solutions and micellar growth are presented and discussed. 相似文献
992.
Summary: A comparative study of the performances of (bpzmp)ZrBz3 ( 1 ) and (hppzm)ZrBz3 ( 2 ) activated with B(C6F5)3 or [Ph3C][B(C6F5)4] in ethylene polymerisation pointed out that the steric properties of the metal complex and the boron activator affect the productivity of the catalyst and, more remarkably, the microstructure of the polyethylenes produced. A polymerisation mechanism accounting for these results has been proposed.
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Summary: The nanoindentation test is a fundamental tool to assess the link between morphology and mechanical properties. The preliminary results of a more exhaustive study about the applicability to polymers of the most used procedure to determine elastic modulus by indentation are reported in this short communication. A departure of the experimental conditions from the theoretical assumptions and results that give rise to the Oliver and Pharr analysis is shown to occur under a wide range of experimental conditions, with applied loads and penetration depths covering several orders of magnitude and using different indenter geometries. Unloading curves with exponents significantly larger than 2 are observed in disagreement with the contact mechanics approach used by Oliver and Pharr.
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In this paper, we consider a bankruptcy problem with the additional constraint that the estate has to be assigned in integer unities; differently from the approaches by other authors, we allow for non-integer claims. This situation poses new questions on the existence and the uniqueness of the solution. We propose a new solution method that leads to the “box solution”, for which uniqueness may be guaranteed introducing a ranking on the claimants. Some examples complete the paper. 相似文献