排序方式: 共有48条查询结果,搜索用时 15 毫秒
1.
J. P. Girardeau-Montaut M. Afif C. Girardeau-Montaut S. D. Moustaïzis N. Papadogiannis 《Applied Physics A: Materials Science & Processing》1996,62(1):3-6
The sensitivity of photoelectric emission of polycrystalline aluminium, produced by 248 nm laser pulses with p-polarization and 450 fs duration, under incidence angles = 74–86°, has been measured. A nonlinear increase of photoemission efficiency, as a function of the incident laser peak intensity in the range of 1–50 GW/cm2, was displayed, which confirms earlier observations with gold and tungsten. This nonlinearity is consecutive to the non-thermal distribution of electron gas of laser-heated metal on the time scale of the electron-phonon relaxation time. Analysis of experimental data, using the model previously developed by us [1], gives a value of electron-phonon relaxation time 0.55 ± 0.11 ps. 相似文献
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C. Tomas J.P. Girardeau-Montaut M. Afif M. Romand M. Charbonnier T.M. Duc 《Applied Physics A: Materials Science & Processing》1997,64(5):467-471
3+ :YAG laser with 5th harmonic generator, generating 16 ps duration pulses at 213 nm, with energies up to 0.5 mJ. Experimental results concerning
the action of laser pulses, as well as the effects of residual pressure on the cleanliness of the photocathodes surface are
presented and discussed. Influence of laser pulses and residual pressure on the work function of the metal are also investigated.
Received: 15 April 1996/Accepted: 5 November
1996 相似文献
4.
This paper deals with a characterization of a multivariate stable process using an independence property with a positive random variable. Moreover, we establish a characterization of a multivariate Lévy process based on the notion of cut in a natural exponential family. This allows us to draw some related properties. More precisely, we give the probability density function of this process and the law of the mixture of the Lévy process governed by the convolution semigroup with respect to an exponential random variable. These results are confidentially connected with the univariate case given by [G. Letac and V. Seshadri, Exponential stopping and drifted stable processes, Stat. Probab. Lett., 72:137–143, 2005]. 相似文献
5.
Afif Ahmed Radenahmad Nikdalila Rahman Seikh Mohammad Habibur Torino Nico Saqib Muhammad Hossain Shahzad Park Jun-Young Azad Abul Kalam 《Journal of Solid State Electrochemistry》2022,26(1):111-120
Journal of Solid State Electrochemistry - Protonic ceramic fuel cells have become extremely interesting due to their high power output at the intermediate temperature range... 相似文献
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Mediterranean Journal of Mathematics - The normal inverse Gaussian distributions are used to introduce the class of multivariate normal α-stable distributions. Some fundamental properties of... 相似文献
7.
In recent years, there is an increased demand on the international market of dried fruits and vegetables with significant added value. Due to its important production, consumption and nutrient intake, drying of tomato has become a subject of extended and varied research works. The present work is focused on the drying behavior of thin-layer tomato and its mathematical modeling in order to optimize the drying processes. The moisture desorption isotherms of raw tomato were determined at four temperature levels namely 45, 50, 60 and 65 °C using the static gravimetric method. The experimental data obtained were modeled by five equations and the (GAB) model was found to be the best-describing these isotherms. The drying kinetics were experimentally investigated at 45, 55 and 65 °C and performed at air velocities of 0.5 and 2 m/s. In order to investigate the effect of the exchange surface on drying time, samples were dried into two different shapes: tomato halves and tomato quarters. The impact of various drying parameters was also studied (temperature, air velocity and air humidity). The drying curves showed only the preheating period and the falling drying rate period. In this study, attention was paid to the modeling of experimental thin-layer drying kinetics. The experimental results were fitted with four different models. 相似文献
8.
Afif Ben Amar 《Annali dell'Universita di Ferrara》2012,58(1):1-10
In this work, using an analogue of Sadovskii’s fixed point result for multi-valued mappings with weakly sequentially closed
graph, we prove new multi-valued analogues of Krasnoselskii fixed point theorem for mappings with weakly sequentially closed
graph and under weak topology features. The main condition in our results is formulated in terms of axiomatic measures of
weak noncompactness. 相似文献
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Afif Ben Amar 《Numerical Functional Analysis & Optimization》2013,34(11):1213-1220
We present some new variants of Leray–Schauder type fixed point theorems and eigenvalue results for decomposable single-valued nonlinear weakly compact operators in Dunford-Pettis spaces. 相似文献
10.
In this paper we study spectral properties of a 3 × 3 block operator matrix with unbounded entries and with domain consisting
of vectors which satisfy certain relations between their components. It is shown that, under certain conditions, this block
operator matrix defines a closed operator, and the essential spectra of this operator are determined. These results are applied
to a three-group transport equation. 相似文献