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191.
T.M. Mishonov N. Chéenne D. Robbes J.O. Indekeu 《The European Physical Journal B - Condensed Matter and Complex Systems》2002,26(3):291-296
The generation of harmonics of the voltage response is considered when an AC current is applied through a superconducting
film above Tc. It is shown that almost at all temperatures the mechanism of the temperature oscillations created by the AC current and
the temperature dependence of the resistance dominates over the isothermal nonlinear electric conductivity. Only in a narrow
critical region close to Tc the latter is essential for the generation of the harmonics. A detailed investigation of harmonics generation provides an
accurate method for measuring the thermal boundary conductance between the film and the insulating substrate. The critical
behaviour of the third harmonic will give a new method for the determination of the lifetime of metastable Cooper pairs above
Tc. The comparison of the calculated fifth harmonics of the voltage with the experiment is proposed as an important test for
the applicability of the employed theoretical models.
Received 8 September 2001 相似文献
192.
Stanislav Volkov 《Journal of Theoretical Probability》2006,19(3):691-700
Vertex-reinforced random walk is a random process which visits a site with probability proportional to the weight w
k
of the number k of previous visits. We show that if w
k
∼ k
α, then there is a large time T
0 such that after T
0 the walk visits 2, 5, or ∞ sites when α < 1, = 1, or > 1, respectively. More general results are also proven.
相似文献
193.
N. Ponpandian A. Narayanasamy D. Prabhu K. Ganesan M. Manivel Raja K. Chattopadhyay 《Journal of magnetism and magnetic materials》2006
The Fe73.5Cu1Nb3Si13.5B9 FINEMET alloy has been prepared by the rapid solidification technique. The critical behaviour of this alloy in the amorphous as well as in its nanocrystalline states has been studied near their respective Curie temperatures. From the values of the critical exponents one can conclude that the alloy behaves like a 3D Heisenberg ferromagnet in the amorphous and nanocrystalline states. But there exists a slight increase in the value of β for the alloy annealed at 823 K (the nanocrystalline state) as observed in most of the amorphous alloys. 相似文献
194.
Necessary and sufficient conditions in constrained optimization 总被引:22,自引:0,他引:22
Additional conditions are attached to the Kuhn-Tucker conditions giving a set of conditions which are both necessary and sufficient
for optimality in constrained optimization, under appropriate constraint qualifications. Necessary and sufficient conditions
are also given for optimality of the dual problem. Duality and converse duality are treated accordingly. 相似文献
195.
The phase boundary theory and the contact rule of phase regions are compared, and some weaknesses of the latter are manifested.
The comparison between the Gupta’s method and the boundary theory method for constructing multicomponent isobaric sections
is also presented. 相似文献
196.
Youssef Randjiou 《Journal of Theoretical Probability》2006,19(3):701-720
Let μ+(t) and μ−(t) be the locations of the maximum and minimum, respectively, of a standard Brownian motion in the interval [0,t]. We establish a joint integral test for the lower functions of μ+(t) and μ−(t), in the sense of Paul Lévy. In particular, it yields the law of the iterated logarithm for max(μ+(t),μ−(t)) as a straightforward consequence. Our result is in agreement with well-known theorems of Chung and Erdős [(1952) Trans. Amer. Math. Soc. 72, 179–186.], and Csáki, F?ldes and Révész [(1987) Prob. Theory Relat. Fields
76, 477–497].
相似文献
197.
In this paper, we first reduce the problem of finding a minimum parity (g,f)-factor of a graph G into the problem of finding a minimum perfect matching in a weighted simple graph G*. Using the structure of G*, a necessary and sufficient condition for the existence of an even factor is derived.
This paper was accomplished while the second author was visiting the Center for Combinatorics, Nankai University.
The research is supported by NSFC 相似文献
198.
Sadaharu Jo 《Applied Surface Science》2006,252(10):3514-3519
The morphologies and lattice structures of anthracene single crystals grown from the vapor phase were investigated using optical microscopy, phase contrast microscopy, atomic force microscopy (AFM), and X-ray diffraction analysis. Common morphologies with hexagonal large planes were observed irrespective of crystal size. The observation of certain surface morphologies with a phase contrast microscopy revealed that the spiral steps originated from screw dislocations present on the (0 0 1) planes. Moreover, the center and edge of the (0 0 1) planes had large curvatures, similar to hills. Resultantly, quarter-monolayer (ML) steps were observed on the large and flat planes between both hills. 相似文献
199.
Long JIANG 《数学年刊B辑(英文版)》2006,27(5):553-564
Abstract
Under the Lipschitz assumption and square integrable assumption on g, the author proves that Jensen’s inequality holds for backward stochastic differential equations with generator g if and only if g is independent of y, g(t, 0) ≡ 0 and g is super homogeneous with respect to z. This result generalizes the known results on Jensen’s inequality for g- expectation in [4, 7–9].
*Project supported by the National Natural Science Foundation of China (No.10325101) and the Science Foundation of China University
of Mining and Technology. 相似文献
200.
Jian‐guo Tang 《Mathematical Methods in the Applied Sciences》2006,29(11):1327-1338
An implicit iterative method is applied to solving linear ill‐posed problems with perturbed operators. It is proved that the optimal convergence rate can be obtained after choosing suitable number of iterations. A generalized Morozov's discrepancy principle is proposed for the problems, and then the optimal convergence rate can also be obtained by an a posteriori strategy. The convergence results show that the algorithm is a robust regularization method. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献