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11.
The scope of the paper is the assessment of the technical risk involved in long-term operation of power units. Detailed analyses have been conducted for steam turbine components. The sources and consequences of risk have been identified and the probability of turbine components failure calculated. The quantitative assessment of the risk has been made and possibilities of its reduction discussed. 相似文献
12.
Teresa Mikołajczyk Grażyna Janowska Mariusz Wójcik Maciej Boguń Andrzej Kurzak 《应用聚合物科学杂志》2008,109(4):2513-2521
The rheological properties of spinning solutions of polyacrylonitrile in dimethyl formamide (DMF) containing various amounts of a ferromagnetic nanoaddition were investigated. The porous structure, the strength and thermal properties of fibers obtained from these solutions were assessed, as well as the uniformity of the nanoaddition distribution on the fiber surface was estimated. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 相似文献
13.
Andrzej Lingas 《Information Processing Letters》2007,104(6):220-227
In 1986, Keil provided an O(n2) time algorithm for the problem of covering monotone orthogonal polygons with the minimum number of r-star-shaped orthogonal polygons. This was later improved to O(n) time and space by Gewali et al. in [L. Gewali, M. Keil, S.C. Ntafos, On covering orthogonal polygons with star-shaped polygons, Information Sciences 65 (1992) 45-63]. In this paper we simplify the latter algorithm—we show that with a little modification, the first step Sweep1 of the discussed algorithm—which computes the top ceilings of horizontal grid segments—can be omitted.In addition, for the minimum orthogonal guard problem in the considered class of polygons, our approach provides a linear time algorithm which uses O(k) additional space, where k is the size of the optimal solution—the algorithm in [L. Gewali, M. Keil, S.C. Ntafos, On covering orthogonal polygons with star-shaped polygons, Information Sciences 65 (1992) 45-63] uses both O(n) time and O(n) additional space. 相似文献
14.
A linear correlation was shown to exist between the acidity and the cyclic voltammetric half-potential of the reduction of acids in DMF for carboxylic and N-acids in the pKa range of 6-16. Chlorophenols are reduced at slightly lower potentials giving a separate parallel line. Applying the obtained equation and employing the same method to literature data in DMSO, the pKa values for conjugate aids of DMF and DMSO can be calculated, showing DMSO·H+ to be more acidic (pKa = 2.9) than DMF·H+ (pKa = 5.7). The analysis of cyclovoltammetric data demonstrated that a CE mechanism operates in the reduction of strong acids, including the conjugate acid of DMF. Weaker acids are reduced by direct discharge or a mixed mechanism. 相似文献
15.
A grid (or a mesh) is a two-dimensional permutation: an m× n-grid of size mn is an m× n-matrix where the entries run through the elements {1,2, …, mn}. We prove that if δ1 and δ2 are any two linear orders on {1,2, …, N}, then they can be simultaneously embedded (in a well defined sense) into a unique grid having the smallest size. 相似文献
16.
Andrzej Filinski 《Higher-Order and Symbolic Computation》1994,7(1):11-37
In a simply-typed, call-by-value (CBV) language with first-class continuations, the usual CBV fixpoint operator can be defined in terms of a simple, infinitely-looping iteration primitive. We first consider a natural but flawed definition, based on exceptions and “iterative deepening” of finite unfoldings, and point out some of its shortcomings. Then we present the proper construction using full first-class continuations, with both an informal derivation and a proof that the behavior of the defined operator faithfully mimics a “built-in” recursion primitive. In fact, given an additional uniformity assumption, the construction is a two-sided inverse of the usual definition of iteration from recursion. Continuing, we show that the CBV looping primitive is in fact the direct-style equivalent of a continuation-passing-style fixpoint, and that this correspondence extends all the way to traditional definitions of these operators in terms of reflexive types. 相似文献
17.
Andrzej Brykalski 《International Journal of Heat and Mass Transfer》1985,28(3):613-620
In the paper the general Galerkin method has been applied for the determination of the equivalent time constant of diffusion processes. After establishing the step function response the general formulas have been obtained, which allow for the consideration of boundary conditions of various kinds. The method has been illustrated with some numerical examples. 相似文献
18.
The role of silicon dioxide layers in microelectronics and the importance of their integrity are undisputable. From passivating coatings and masking layers for diffusion to ultra-thin tunneling films — all the silicon technology could not exist without silicon dioxide. This review deals with some aspects of the integrity of thin silicon dioxide films for VLSI applications. The problems of dielectric strength and wear-out are considered from the point of view of their mechanisms, models, oxide processing dependence, testing, and measuring. A brief presentation of statistical approaches commonly applied to reliability topics is also included. 相似文献
19.
Bronisław Jańczuk Tomasz Białopiotrowicz Emil Chibowski Andrzej Dawidowicz Anna Kliszcz 《Journal of Materials Science》1990,25(3):1682-1685
The contact angles of water drops and diiodomethane drops on pellets made of controlled porosity glasses have been measured. The surface of the glasses was modified by thermal treatment at 873 K which led to an increase in the surface concentration of boron atoms. Glass modified with Carbowax 20M (polyethylene glycol) and fully hydroxylated glass have also been studied. Using the measured contact angles and modified Young equation, the dispersion and nondispersion components of the glass surface free energy have been calculated. The values show that with increasing heating time (increasing surface density of boron atoms) an increase in the surface polarity takes place. However, the polarity of the same samples decreases after treatment with Carbowax, increasingly so with higher boron atom concentrations. 相似文献
20.
Chen G Deng Q Szymczak A Laramee RS Zhang E 《IEEE transactions on visualization and computer graphics》2012,18(5):767-782
Morse decomposition provides a numerically stable topological representation of vector fields that is crucial for their rigorous interpretation. However, Morse decomposition is not unique, and its granularity directly impacts its computational cost. In this paper, we propose an automatic refinement scheme to construct the Morse Connection Graph (MCG) of a given vector field in a hierarchical fashion. Our framework allows a Morse set to be refined through a local update of the flow combinatorialization graph, as well as the connection regions between Morse sets. The computation is fast because the most expensive computation is concentrated on a small portion of the domain. Furthermore, the present work allows the generation of a topologically consistent hierarchy of MCGs, which cannot be obtained using a global method. The classification of the extracted Morse sets is a crucial step for the construction of the MCG, for which the Poincare′ index is inadequate. We make use of an upper bound for the Conley index, provided by the Betti numbers of an index pair for a translation along the flow, to classify the Morse sets. This upper bound is sufficiently accurate for Morse set classification and provides supportive information for the automatic refinement process. An improved visualization technique for MCG is developed to incorporate the Conley indices. Finally, we apply the proposed techniques to a number of synthetic and realworld simulation data to demonstrate their utility. 相似文献