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201.
Mathematical models of the reliability assessment of a structure treated as the time to the first passage of the capacity which is degrading in the time are presented. Two stochastic models of the structure degradation caused by different factors and two stochastic models of loading are considered. The relationships for calculating the probability of failure for presented models of the structure load and the capacity degradation, are given. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
202.
An example of two distinguished Fréchet spaces E, F is given (even more, E is quasinormable and F is normable) such that their completed injective tensor product E?F is not distinguished. On the other hand, it is proved that for arbitrary reflexive Fréchet space E and arbitrary compact set K the space of E - valued continuous functions C(K, E) is distinguished and its strong dual is naturally isomorphic to ? where L1(μ) = C(K)1. 相似文献
203.
204.
Pawel Sikorski Sharon J. Cooper Edward D. T. Atkins Gary D. Jaycox Otto Vogl 《Journal of polymer science. Part A, Polymer chemistry》1998,36(11):1855-1860
Minimum potential energy helical conformations for a family of four isotactic polyacetaldehydes have been determined. Our results indicate that all of the polymers form irrational helices. Comparisons have been made with the reported structures for two of these stereoregular polymers based on earlier X-ray diffraction data. c-Axis values associated with the pitch of the helix for polyacetaldehyde and for polytrichloroacetaldehyde (polychloral) were experimentally measured to be 0.48 and 0.51 nm, respectively. Our calculated conformations afforded values for a helix pitch of 0.47 and 0.52 nm, respectively, which derive from a 3.9/1 helix for polyacetaldehyde and a 3.7/1 helix for polychloral. The structure for polytribromoacetaldehyde (polybromal) was predicted to be similar to that for polychloral. For polytrifluoroacetaldehyde (polyfluoral) and polyacetaldehyde, a number of helical conformations with similar energies were found. All of these conformations could be related to the polychloral helical structure. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 1855–1860, 1998 相似文献
205.
The paper deals with the NP-hard problems of minimizing the makespan in m-machine no-wait and no-idle permutation flow shops. We identify networks whose longest path lengths represent the makespans. These networks reveal the duality between the two problems, and show graphical explanations of the fact that under no-wait and no-idle conditions the makespan can be a decreasing function of some job processing times. Moreover, they also lead to a natural reduction of the no-wait flow shop problem to the traveling salesman problem, some lower bounds on the shortest makespan, and new efficiently solvable special cases. 相似文献
206.
James A. Cox Anna M. Wolkiewicz Pawel J. Kulesza 《Journal of Solid State Electrochemistry》1998,2(4):247-252
Voltammetry of silicotungstic acid (STA), H4SiW12O40, that was encapsulated in silica was performed in the absence of a contacting liquid phase. Two one-electron reductions that are separated by 200?mV were observed, which is the same behavior as in aqueous solution. At scan rates, v, below 10?mV s?1 with a 10?μm dia. carbon fiber indicator electrode, plateaus with limiting currents which are independent of v were observed, which is indicative of spherical diffusion from a field that is much larger than the electrode area. At v?>?20?V?s?1, peaks were observed with currents directly proportional to v ½. For a gel aged for 2 days, an effective diffusion coefficient, D eff, of 3?×?10?7?cm2 s?1 was estimated by voltammetry and chronoamperometry; the concentration of the redox sites thereby determined was about 0.5?M. The D eff values that were obtained in this study were larger than expected for a solid electrolyte, which suggests an important role of residual water. In support of this model, gels that were aged in a humidistat at 33% humidity at room temperature for 2 and 5 days lost 16% and 13%, respectively, of their mass when dried at 120°. 相似文献
207.
本文提出两个均匀性统计量用于检验多元正态性.该检验建立在多元正态分布的一个特征性质基础上,模拟研究和实例分析显示该均匀性统计量可以帮助解释来自已有正态性检验统计量的结论. 相似文献
208.
Tadeusz Martynkien Marcin Szpulak Gabriela Statkiewicz Grzegorz Golojuch Jacek Olszewski Waclaw Urbanczyk Jan Wojcik Pawel Mergo Mariusz Makara Tomasz Nasilowski Francis Berghmans Hugo Thienpont 《Optical and Quantum Electronics》2007,39(4-6):481-489
We report on experimental studies of polarimetric sensitivity to hydrostatic pressure and temperature in two highly birefringent
index guided photonic crystal fibers, in which birefringence is induced by one row of the cladding holes with diameters smaller
than the other cladding holes. The sensitivity measurements were carried out in the spectral range from 0.6 μm to 1.6 μm.
Our results show that absolute value of the polarimetric sensitivity to hydrostatic pressure can reach 23 rad/MPa × m, which
is almost one order of magnitude higher than in conventional fibers with elliptical core. Simultaneously, polarimetric sensitivity
to temperature is at least two orders of magnitude lower than in conventional highly birefringent fibers. Moreover, we proved
experimentally that one of the investigated fibers is completely insensitive to temperature at certain wavelength. 相似文献
209.
210.
We prove that the Conway polynomial of oriented links is not changed by the rotation operation of Anstee, Przytycki and Rolfsen.Mathematics Subject Classifications (2000). 57M25, 57M27Supported by KBN grant No 2P03A00218 相似文献