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101.
P. G. Siddheshwar R. K. Vanishree Anthony Christy Melson 《Transport in Porous Media》2012,92(2):277-288
The effects of temperature-dependent viscosity, gravity modulation and thermo-mechanical anisotropies on heat transport in a low-porosity medium are studied using the Ginzburg–Landau model. The effect of gravity modulation is to decrease the Nusselt number, Nu and variable viscosity leads to increase in Nu. The thermo-mechanical anisotropies have opposite effect on Nu with thermal anisotropy decreasing the heat transport. 相似文献
102.
Antonio Strozzi 《Journal of Elasticity》2012,108(1):119-123
The solution of cylindrical problems is addressed. A series solution is considered of the biharmonic equation, in which the series terms of the stress function Φ are expressions based upon Legendre polynomials and logarithmically singular functions. An explicit form of a polynomial supplementing each logarithmically singular part of the series solution is obtained. 相似文献
103.
We consider the flow of a viscous incompressible fluid in a pipe when the boundary is a deformable shell of Naghdi type. We prove that the corresponding system of partial differential equations has a solution when the deformation of the shell is smooth and small enough. We propose an algorithm that uncouples the unknowns and prove its convergence. 相似文献
104.
We apply the recently improved version of the 0–1 test for chaos to real experimental time series of laser droplet generation process. In particular two marginal regimes of dripping are considered: spontaneous and forced dripping. The outcomes of the test reveal that both spontaneous and forced dripping time series can be characterized as chaotic, which coincides with the previous analysis based on nonlinear time series analysis. 相似文献
105.
Jaume Llibre Paulo R. da Silva Marco A. Teixeira 《Journal of Dynamics and Differential Equations》2012,24(1):1-12
In this article we establish an interaction between non-smooth systems, geometric singular perturbation theory and synchronization phenomena. We find conditions for a non-smooth vector fields be locally synchronized. Moreover its regularization provide a singular perturbation problem with attracting critical manifold. We also state a result about the synchronization which occurs in the regularization of the fold-fold case. We restrict ourselves to the 3-dimensional systems (ℓ = 3) and consider the case known as a T-singularity. 相似文献
106.
We derive the Kramers equation, namely, the Fokker-Planck equation for an oscillator, from a completely deterministic picture. The oscillator is coupled to a “booster”, i.e., a deterministic system in a fully chaotic state, wherein diffusion is derived from the sensitive dependence of chaos on initial conditions and friction is a consequence of the linear response of the booster to the action exerted on it by the oscillator. To deal with the Hamiltonian nature of the system of interest and of its coupling to the booster, we extend the earlier theoretical derivation of macroscopic transport coefficients from deterministic dynamics. We show that the frequency of the oscillator can be tuned to the microscopic frequencies of the booster without affecting the canonical nature of the “macroscopic” statistics. The theoretical predictions are supported by numerical simulations. 相似文献
107.
Summary Differential scanning calorimetric measurements in the early stage of isothermal crystal growth of polyethylene oxide are
analysed in the light of irreversible thermodynamics. An accurate evaluation of the equilibrium melting temperature is done
by fitting the thermograms obtained at different undercoolings and referring to the activation energy values already known
from the literature.
Paper presented at the I International Conference on Scaling Concepts and Complex Fluids, Copanello, Italy, July 4–8, 1994. 相似文献
108.
A rigorous wave-theoretic approach to the Michelson-Morley (M-M) experiment is presented, with special emphasis on the Huygens' principle derivation of the laws of reflection by a moving mirror. A detailed discussion of the Lorentz-Fitzgerald contraction hypothesis (CH) is included. Several mistakes appearing in the standard textbook treatments of these issues are pointed out, and a number of related historical questions are considered. 相似文献
109.
Summary The results of an investigation are presented in which it is shown how the spatial inhomogeneity of a laser field modifies
the multiphoton free-free transition cross-sections compared to the case of a homogeneous field. This kind of investigation
is required to make more close contact with experiments in intense fields, as in these cases the inhomogeneity is produced
by the focusing of the laser beam. Furthermore, taking into account the intensity spatial distribution allows us to achieve
in an effective way the asymptotic decoupling of the scattered particles from the field, which is very important for theoretical
models using asymptotic initial and final states embedded in the field. Differential and total cross-sections are calculated
over a wide range of parameters as functions of the scattering angle, of the incoming-particle energy and of the laser intensity
and frequency. The laser spatial inhomogeneity is found to wash out most of the oscillating behaviour of multiphoton differential
cross-sections, derived within the model of a homogeneous laser. Little modifications are, instead, found in the total cross-sections
which are simply scaled to slightly lower values. Crosssections with zero photon exchange are increased, while those with
photon exchanges are lowered. This yields the result that the sum of all the ≪inhomogeneous≫ cross-sections is equal to the
sum of all the ≪homogeneous≫ ones (sum rule). The multiphoton free-free transition differential cross-sections are found to
be very sensitive quantities which may be used to get information on the laser properties and on their nonlinear behaviour,
when these are not precisely known.
To speed up publication, the authors of this paper have agreed to not receive the proofs for correction. 相似文献
110.
Marco Degiovanni 《Annali di Matematica Pura ed Applicata》1990,156(1):37-71
Summary A class of extended real valued functionals, already considered for evolution problems, is studied. The set where the functional is finite is proved to be an absolute neighborhood extensor. Applications to critical point theory, involving Ljusternik-Schnirelman category and cohomological index, are shown. The stability under -convergence of the homotopical type of the sublevels of the functional is also treated.The author is a member of theGruppo Nazionale per l'Analisi Funzionalc e le sue Applicazioni (C.N.R.). 相似文献