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51.
Leonid A. Dombrovsky Jaona H. Randrianalisoa Wojciech Lipiński 《Journal of Quantitative Spectroscopy & Radiative Transfer》2011,112(12):1987-1994
A two-step approximate analytical solution for the normal emittance of a plane layer of an absorbing, scattering and refracting medium is derived analytically. The analysis is based on the transport approximation and the two-step solution method for radiative transfer. The high accuracy of the approximate solution, examined by comparing its results to those obtained independently by the discrete ordinates and Monte Carlo methods, makes it suitable for application in combined experimental-analytical studies to identify selected spectral radiative properties of dispersed media in the range of semi-transparency. 相似文献
52.
We consider derivation of the effective potential for a scalar field in curved space-time within the physical regularization scheme, using two sorts of covariant cut-off regularizations. The first one is based on the local momentum representation and Riemann normal coordinates and the second is operatorial regularization, based on the Fock-Schwinger-DeWitt proper-time representation. We show, on the example of a self-interacting scalar field, that these two methods produce equal results for divergences, but the first one gives more detailed information about the finite part. Furthermore, we calculate the contribution from a massive fermion loop and discuss renormalization group equations and their interpretation for the multi-mass theories. 相似文献
53.
54.
We introduce the monotone Sokolov property and show that it is dual to monotone retractability in the sense that X is monotonically retractable if and only if Cp(X) is monotonically Sokolov. Besides, a space X is monotonically Sokolov if and only if Cp(X) is monotonically retractable. Monotone retractability and monotone Sokolov property are shown to be preserved by R-quotient images and Fσ-subspaces. Furthermore, every monotonically retractable space is Sokolov so it is collectionwise normal and has countable extent. We also establish that if X and Cp(X) are Lindelöf Σ-spaces then they are both monotonically retractable and have the monotone Sokolov property. An example is given of a space X such that Cp(X) has the Lindelöf Σ-property but neither X nor Cp(X) is monotonically retractable. We also establish that every Lindelöf Σ-space with a unique non-isolated point is monotonically retractable. On the other hand, each Lindelöf space with a unique non-isolated point is monotonically Sokolov. 相似文献
55.
In this paper we study polynomial normal forms and smooth (C∞) classification of one kind of diffeomorphisms which have infinite many resonant relations but are finitely determined. We derive a complete list of normal forms of all such germs with arbitrary degeneracy of their nonlinear parts. 相似文献
56.
《Communications in Nonlinear Science & Numerical Simulation》2014,19(7):2294-2308
This paper presents an explicit, computationally efficient, recursive formula for computing the normal forms, center manifolds and nonlinear transformations for general n-dimensional systems, associated with semisimple singularities. Based on the formula, we develop a Maple program, which is very convenient for an end-user who only needs to prepare an input file and then execute the program to “automatically” generate the result. Several examples are presented to demonstrate the computational efficiency of the algorithm. 相似文献
57.
Patrick Dehornoy 《Journal of Combinatorial Theory, Series A》2007,114(3):389-409
Many natural counting problems arise in connection with the normal form of braids—and seem to have not been much considered so far. Here we solve some of them. One of the noteworthy points is that a number of different induction schemes appear. The key technical ingredient is an analysis of the normality condition in terms of permutations and their descents, in the vein of the Solomon algebra. As was perfectly summarized by a referee, the main result asserts that the size of the automaton involved in the automatic structure of Bn associated with the normal form can be lowered from n! to p(n), the number of partitions of n. 相似文献
58.
Traditionally, the components of the stress with respect to a relevant coordinate system are used for the purpose of stress
visualisation and interpretation. A case for using a flow dependent measure to interpret and visualise stress is made for
two dimensional flow, together with a suggestion for extending the idea to three dimensions. The method is illustrated for
Newtonian and Oldroyd B fluids in both the eccentrically rotating cylinder and flow past a cylinder benchmark problems. In
the context of a generalised Newtonian fluid, the relation between the flow-dependent stress measure to other field variables
under certain flow conditions, is examined and is indicative of its importance in complex flow.
相似文献
P. C. BolladaEmail: |
59.
Selva Pereda Javeed A. Awan Amir H. Mohammadi Alain Valtz Christophe Coquelet Esteban A. Brignole Dominique Richon 《Fluid Phase Equilibria》2009
In this communication, new experimental data on the solubility of n-hexane, cyclo-hexane and iso-octane in pure water are reported. The data have been measured using a static-analytic technique that takes advantage of a Rolsi™ sampling device in the temperature range of 298–353 K and at pressures up to 0.5 MPa. The experimental data measured in this work at 298 K have been compared with some selected data from the literature and good agreement is found. A group contribution plus association equation of state, namely the GCA-EoS, is used to model the phase equilibrium of water + hydrocarbon (C2 to n-C6, cy-C6, i-C4 and i-C8) system. The predictions of the model are found in good agreement with the experimental data measured in this work and some selected data from the literature. 相似文献
60.
James Murdock 《Journal of Differential Equations》2004,205(2):424-465
Hypernormal forms (unique normal forms, simplest normal forms) are investigated both from the standpoint of foundational theory and algorithms suitable for use with computer algebra. The Baider theory of the Campbell-Hausdorff group is refined, by a study of its subgroups, to determine the smallest substages into which the hypernormalization process can be divided. This leads to a linear algebra algorithm to compute the generators needed for each substage with the least amount of work. A concrete interpretation of Jan Sanders’ spectral sequence for hypernormal forms is presented. Examples are given, and a proof is given for a little-known theorem of Belitskii expressing the hypernormal form space (in the inner product style) as the kernel of a higher-order differential operator. 相似文献