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101.
C.-A. Pillet 《Communications in Mathematical Physics》1991,140(2):241-274
We develop a scheme based on pseudo-differential operators to analyze the propagation of excitations in inhomogeneous extended systems. This method is used in a very specific situation, however we think that it has some generality and should apply to various other problems of current interest. We study the well known two-dimensionalsymmetric model of solidification introduced by Langer and Turski. Assuming the existence of Ivantsov-like steady-state solutions, we calculate their excitation spectrum. We show that there are no unstable propagating modes if the Gibbs-Thomson effect is taken into account. This proves that the growth of needle-crystals is stable with respect to side-branching. 相似文献
102.
F. D. Saccone C. E. Rodrí guez Torres F. H. S nchez O. Gutfleisch 《Physica B: Condensed Matter》2002,320(1-4):312-315
In the present work, a quantitative analysis of the phase compositions by Mössbauer effect spectroscopy of solid and conventional hydrogen disproportionated Pr13.7Fe80.3B6.0 and Pr13.7Fe63.5Co16.7Zr0.1B6.0 alloys was carried out. Significant amounts of intermediate borides t-Fe3B and Pr(Fe, Co)12B6 were detected after solid hydrogen disproportionation treatment in Pr13.7Fe80.3B6.0 and Pr13.7Fe63.5Co16.7Zr0.1B6.0 alloys, respectively. After conventional hydrogenation–disproportionation–desorption–recombination treatment these phases were not detected and in no case residual Pr2Fe14B-phase was found. It was observed that the amount of intermediate borides after disproportionation can be correlated with the degree of texture after recombination at various temperatures. 相似文献
103.
104.
L. Galeone C. Mastroserio M. Montrone 《Numerical Methods for Partial Differential Equations》1989,5(2):79-86
This paper presents the study of the numerical solution of a reaction-diffusion system involving a reaction term of integral type arising from biological models. By means of a monotone approach we introduce upper and lower solutions and then we show the existence and the asymptotic behavior of nonnegative numerical solutions. To this end, we require the positivity of the numerical scheme and so we can use some properties of positive and M-matrices. Finally we give some sufficient conditions to verify the asymptotic stability of the numerical solution. 相似文献
105.
Janine C. Swarbrick 《Applied Surface Science》2006,252(15):5622-5626
We have used the established technique of electrospray in developing a portable vacuum electrospray system which can deposit, in vacuo, dissolved molecules onto a sample which may then be analysed by UHV techniques. As an initial test of the system we have analysed silicon samples with an electrosprayed layer of poly(ethylene) oxide (PEO) using atomic force microscopy (AFM). The polymer forms different structures depending on the voltage applied to the emitter, and solution composition. The system is part of our ongoing effort to deposit other materials such as nanoparticles, and large dye molecules for developing molecular dye sensitised solar cells. 相似文献
106.
107.
P. C. Mehta 《Hyperfine Interactions》1987,37(1-4):325-345
Optical data processing is an advancing field which has received much attention in recent years. Optical techniques have already
shown their applicability in target identification, advanced signal processing operations and advanced linear algebra operations.
The potential capabilities of processing of data using photons instead of electrons as the carrier of information have established,
beyond any doubt, that the optical techniques will be the next generation technology surpassing electronic techniques in some
important areas such as air traffic control, missile guidance and remote sensing. Although great strides have been made in
all the areas of optical data processing, the goal of high performance, high speed and very accurate all-optical computers
would be realised only around the year 1995. The main difficulty is that the required materials for high resolution and fast
spatial light modulators and optical interconnects are yet to be perfected. The present paper reviews the recent trends and
the future prospects of optical data processing. 相似文献
108.
109.
Venzo de Sabbata P. I. Pronin C. Sivaram 《International Journal of Theoretical Physics》1991,30(12):1671-1678
We consider the possibility of finding experimental evidence of the fifth force with the measurement of a phase shift of neutron beams via an interferometric apparatus and also a possible rotation of the polarization plane of polarized neutron beams when torsion is introduced in a gravitational field. 相似文献
110.