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91.
This paper is devoted to study the existence of solutions and their regularity in the –Laplacian Dirichlet problem on a bounded time scale. First, we prove a lemma of du Bois–Reymond type in time-scale settings. Then, using direct variational methods and the mountain pass methodology, we present several sufficient conditions for the existence of solutions to the Dirichlet problem. 相似文献
92.
Doried?GhaderEmail author Vinod?Ashokan Michel Abou?Ghantous Antoine?Khater 《The European Physical Journal B - Condensed Matter and Complex Systems》2013,86(4):180
A model calculation is presented for the spin wave scattering and coherent transport at the ferrimagnetically ordered cobalt-gadolinium alloy nanojunction between cobalt leads. The structural model for the amorphous alloy nanojunction [Co1/2Gd1/2]3 is considered as an ordered alloy hcp structure of three (0001) atomic planes between the leads. To analyze the spin dynamics and spin wave scattering at the nanojunction boundary, the phase field matching method (PFMT) is implemented over the ground state of the system, in the Heisenberg Hamiltonian representation. The coherent reflection and transmission probabilities of spin waves from the cobalt leads incident onto the nanojunction boundary are calculated, and numerical results are presented for the coherent SW transport across the nanojunction over the entire range of their frequencies. The results are especially valid in the interval between nanometric SW wavelengths greater than the nanojunction width and macroscopic wavelengths. They demonstrate in particular, the possibility of the resonance assisted maxima for the SW transmission spectra owing to the interactions between the incident spin waves and the localized spin resonances on the nanojunction. This effect is general and may be observed at different characteristic frequencies and corresponding incident angles. 相似文献
93.
The successive steps of the computer analysis of a NMR spectrum are examined. Better results can be obtained by direct simulation of tentative model spectra. As an example the 1H-NMR spectrum of amphetamine is analysed. 相似文献
94.
Abstract Neptunium and plutonium monosulfides were studied under high pressure up to ~60 GPa using a diamond anvil cell in an energy dispersive X-ray diffraction facility. The compounds, of cubic rock salt structure type at ambient pressure, do not show any crystallographic phase transition in the domain of investigation. From the pressure-volume relationship, we determined bulk moduli of 92 and 120 GPa with pressure derivatives of 4.6 and 4.1 for NpS and PUS respectively. 相似文献
95.
Jean Bricmont Jean-Raymond Fontaine Joel L. Lebowitz Thomas Spencer 《Communications in Mathematical Physics》1981,78(3):363-371
We consider perturbations of a massless Gaussian lattice field on ? d ,d≧3, which preserves the continuous symmetry of the Hamiltonian, e.g., $$ - H = \sum\limits_{< x,y > } {(\phi _x - \phi _y )^2 + T(\phi _x - \phi _y )^4 ,\phi _x \in \mathbb{R}.} $$ It is known that for allT>0 the correlation functions in this model do not decay exponentially. We derive a power law upper bound for all (truncated) correlation functions. Our method is based on a combination of the log concavity inequalities of Brascamp and Lieb, reflection positivity and the Fortuin, Kasteleyn and Ginibre (F.K.G.) inequalities. 相似文献
96.
Speckle photography experiments have been used for studying optical systems and more recently we have used image speckle photography to measure displacements and deformations of a partial diffuser. The same method is now used for studying chromatic aberrations of a lens system. Experimental results are given for three optical lenses. 相似文献
97.
Alain Tressaud Jean Louis Soubeyroux Jean Michel Dance René Sabatier Paul Hagenmuller Barbara M. Wanklyn 《Solid State Communications》1981,37(6):479-484
The nature of the magnetic interactions in the chain compound Rb2FeF5 has been investigated using neutron diffraction and magnetic measurements under high applied fields. Rb2FeF5 orders antiferromagnetically at TN = 8.0 ± 0.5 K; the magnetic structure is of the AZ + GX mode and the moment of the Fe3+ ion extrapoled to 0K is 3.5 ± 0.2 μB, this low value being due to zero-point spin reduction. Within a chain the Fe3+ ions are antiferromagnetically coupled with an exchange constant of J/k = ?8.8 K. A spin-flop behavior has been observed and interpreted on the basis of the molecular field theory. The critical field was found to be HC = 65 kOe at 1.7 K. 相似文献
98.
Summary We consider a one-dimensional linear wave equation with a small mean zero dissipative field and with the boundary condition imposed by the so-called Goursat problem. In order to observe the effect of the randomness on the solution we perform a space-time rescaling and we rewrite the problem in a diffusion approximation form for two parameter processes. We prove that the solution converges in distribution toward the solution of a two-parameter stochastic differential equation which we identify. The diffusion approximation results for oneparameter processes are well known and well understood. In fact, the solution of the one-parameter analog of the problem we consider here is immediate. Unfortunately, the situation is much more complicated for two-parameter processes and we believe that our result is the first one of its kind.Partially supported by ONR N00014-91-J-1010 相似文献
99.
Jean d'Almeida 《Archiv der Mathematik》1994,62(5):408-410
Sans résumé 相似文献
100.
Jean Saint Raymond 《Set-Valued and Variational Analysis》1994,2(3):481-485
LetX be a Polish space equipped with a σ-finite regular Borel measure μ. IfE is a metric space andF a set-valued function:X → 2 E with complete values, and ifF is lower semicontinuous at almost all points ofX, we prove that there exists a Riemann-measurable selections ofF. 相似文献