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91.
A general solution to nonsteady coupled magnetohydrodynamic plane Couette flow by the method of Fourier series expansion is
presented in this paper. Two particular examples of the utility of the solution are included: 1) an impulsive start of the
wall, and 2) a wall velocity proportional to (1 − exp(− αt)).
For the case of an impulsive start of the wall it is found that flow is apparently accelerated by the presence of the magnetic
field, a situation opposite to that which occurs when no induced magnetic field is allowed. 相似文献
92.
93.
94.
C. Magron Ph. Alfaurt B. Blank L. Daudin T. Eronen M. Gerbaux J. Giovinazzo D. Gorelov S. Grévy H. Guérin J. Hakala V. S. Kolhinen J. Koponen T. Kurtukian Nieto I. D. Moore H. Penttilä I. Pohjalainen J. Reinikainen M. Reponen S. Rinta-Antila M. Roche A. de Roubin N. Smirnova B. Thomas A. Voss L. Xayavong 《The European Physical Journal A - Hadrons and Nuclei》2017,53(4):77
95.
We consider the problem on the stability and instability of the equilibrium in the vertical plane for a wheeled vehicle performing
a uniform rectilinear motion in the presence of rolling friction forces. We assume that the dependence of the rolling friction
coefficients on the motion velocity is known and derive necessary and sufficient conditions on the system parameters under
which such equilibria are stable. 相似文献
96.
We prove some invariance principles for processes which generalize FARIMA processes, when the innovations are in the domain of attraction of a nonGaussian stable distribution. The limiting processes are extensions of the fractional Lévy processes. The technique used is interesting in itself; it extends an older idea of splitting a sample into a central part and an extreme one, analyzing each part with different techniques, and then combining the results. This technique seems to have the potential to be useful in other problems in the domain of nonGaussian stable distributions. 相似文献
97.
I. Nedkov L. Slavov T. Merodiiska P. Lukanov Ph. Tailhades M. Gougeon R. E. Vandenberghe 《Journal of nanoparticle research》2008,10(5):877-880
Ferrofluids based on two types of hybrid particles Fe3O4/β-cyclodextrin were prepared: Using monodomain (below 60 nm) magnetite nanoparticles with (A) non-superparamagnetic (non-SPM)
behaviour and (B) with superparamagnetic (SPM) behaviour. We found a strong dependence of the hybrid particles’ magnetic properties
on their size and homogeneity. In both types of ferrofluids we observed hyperthermia upon applying an ac electromagnetic field
with frequency 40 kHz and amplitude 30 kA/m. The maximal ΔТ upon irradiation with duration of about 12 min for the non-SPM particles was 12 °C, while for the SPM ones it was 3.5 °C. 相似文献
98.
Within the Feynman–Kac path integral representation, the equilibrium quantities of a quantum plasma can be represented by Mayer graphs. The well known Coulomb divergencies that appear in these series are eliminated by partial resummations. In this paper, we propose a resummation scheme based on the introduction of a single effective potential that is the quantum analog of the Debye potential. A low density analysis of shows that it reduces, at short distances, to the bare Coulomb interaction between the charges (which is able to lead to bound states). At scale of the order of the Debye screening length
–1
D, approaches the classical Debye potential and, at large distances, it decays as a dipolar potential (this large distance behaviour is due to the quantum nature of the particles). The prototype graphs that result from the resummation obey the same diagrammatical rules as the classical graphs of the Abe–Meeron series. We give several applications that show the usefulness of to account for Coulombic effects at all distances in a coherent way. 相似文献
99.
Ph. Boullay G. TrolliardD. Mercurio J.M. Perez-MatoL. Elcoro 《Journal of solid state chemistry》2002,164(2):252-260
A generalized structural model of Aurivillius-type compounds is presented using a 4D superspace group analysis where Aurivillius structures are considered as cation-deficient perovskites with the general formula AB1−xO3. Being essentially composition independent, the model is valid for any Aurivillius-type compounds where x is the only composition-dependent parameter. The atomic domains representing the atoms in superspace are described by means of crenel functions. For any composition, the conventional space groups can be easily derived from a unique superspace group. This work is supported by a TEM investigation where the continuously variable character of the diffraction diagram indicates that the various stacking sequences can be interpreted in terms of a structural modulation over a common average structure. 相似文献
100.
Sebban S Mocek T Ros D Upcraft L Balcou P Haroutunian R Grillon G Rus B Klisnick A Carillon A Jamelot G Valentin C Rousse A Rousseau JP Notebaert L Pittman M Hulin D 《Physical review letters》2002,89(25):253901
We report the first experimental demonstration of a Ni-like optical-field ionization collisional soft x-ray laser. The amplifying medium is generated by focusing a circularly polarized 760 mJ, 30 fs, 10-Hz Ti:sapphire laser beam in a few mm cell filled with krypton. We have measured a gain coefficient of 78 cm(-1) on the 3d(9)4d 1S0-3d(9)4p(1)P1 transition at 32.8 nm, which is here amplified for the first time. This radiation source represents the shortest wavelength optical-field ionization collisional soft x-ray laser ever produced. The influence of the gas pressure and the pumping energy on the lasing output are also presented. 相似文献