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1.
Nourredine Akroune 《Comptes Rendus Mathematique》2004,338(11):899-904
In this work, we propose a particular discretization of the size of the grids in order to compute numerically, by the box-counting algorithm, the fractal dimension of a subset in two-dimensional space. The efficiency of the associated method is successfully tested on various examples of fractal sets which are derived from discret dynamical systems. To cite this article: N. Akroune, C. R. Acad. Sci. Paris, Ser. I 338 (2004). 相似文献
2.
E. Khouya S. Fakhi H. Hannache J. C. Abbe Y. Andres R. Naslain R. Pailler A. Nourredine 《Journal of Radioanalytical and Nuclear Chemistry》2004,260(1):159-166
New activated adsorbents for radionuclides have been produced from Moroccan oil shales by pyrolysis of the natural material
at 550 °C flowed by a KMnO4 activation. The texture and composition of the native rock and the adsorbents were studied before their use in tests for
adsorption of radionuclides from standard solutions prepared from uranylnitrate and thorium nitrate in equilibrium with their
daughters. The distribution coefficients between solutions containing U, Th and Ra and the adsorbents were evaluated by means
of specific activities, measured by g-ray spectrometry. The adsorbents were observed to eliminate U, Th, Ra, Ac and Tl from
aqueous solutions.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
3.
Rim Benali‐Cherif Radhwane Takouachet El‐Eulmi Bendeif Nourredine Benali‐Cherif 《Acta Crystallographica. Section C, Structural Chemistry》2014,70(7):689-692
Two polymorphs of L‐aspartic acid hydrochloride, C4H8NO4+·Cl−, were obtained from the same aqueous solution. Their crystal structures have been determined from single‐crystal data collected at 100 K. The crystal structures revealed three‐ and two‐dimensional hydrogen‐bonding networks for the triclinic and orthorhombic polymorphs, respectively. The cations and anions are connected to one another via N—H...Cl and O—H...Cl interactions and form alternating cation–anion layer‐like structures. The two polymorphs share common structural features; however, the conformations of the L‐aspartate cations and the crystal packings are different. Furthermore, the molecular packing of the orthorhombic polymorph contains more interesting interactions which seems to be a favourable factor for more efficient charge transfer within the crystal. 相似文献
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Nawel Cheikh Didier Villemin Nathalie Bar Jean-François Lohier Nourredine Choukchou-Braham Bachir Mostefa-Kara Jana Sopkova 《Tetrahedron》2013,69(3):1234-1247
In the course of our studies on Cerpegin analogues synthesis, a serendipitous reactivity of enaminolactone nitrile has been observed. Instead of expecting iminocerpegins, we have gained new class of substituted 2-aminopyridines. The methodology has been applied on a wide range of primary amines, as aliphatic, aromatic, heteroaromatic and also, diamines, hydrazines and chiral amines. 相似文献
6.
For any simply connected solvable Lie group Q of polynomial volume growth, we introduce the notion of nil-shadow of Q. We shall give an explicit formula for the distance to the origin of an element q ∈ Q in terms of its exponential coordinates of the second kind taken in an appropriate basis. This result extends a previous result for nilpotent Lie groups [6, Theorem DN] and [7, Theorem 1]. 相似文献
7.
Even though carbon nanotubes offer an excellent solution for the design of strain sensors, their widespread commercial utilization has been hampered by the unavailability of design rules, inconsistencies in their macro-scale properties, and lack of understanding of the effects of various parameters on their characteristics. Nevertheless, many researches have been carried out to characterize elastomeric nanocomposites filled with carbon nanotubes in order to optimize their properties such as electrical conductivity and strain sensitivity range. This article reviews the effect of different parameters on the electrical properties of such nanocomposites, followed by the analysis of performances of elastomer strain sensors. 相似文献
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Nourredine Bounechada 《Bulletin des Sciences Mathématiques》2003,127(9):797-813
Let G be a connected nilpotent Lie group and H a connected subgroup of G. We give an explicit formula for the distance to the origin with the exponential coordinates of the second kind of g∈G. Using this fact, we prove that the distance to the origin of any element in H is bounded by a polynomial function of the distance to the origin in the group G. The degree of the polynomial is the nilpotency rank of the group G. 相似文献
10.
Lignocellulosic biomass material sourced from plants and herbaceous sources is considered as a prospective feedstock of inexpensive,potentially carbon-neutral energy.Lignocellulosic biomass is structurally built on cellulose,hemicellulose,and lignin,which are present in varying concentrations based on the feedstock type and play distinct and not well understood mechanical functions in the flow behavior.The frictional characteristics of lignocellulosic biomass particulates influence their flow behavior in biorefineries.Thus,it is important to fundamentally investigate the relative contribution of cellulose,hemicellulose,and lignin to the frictional behavior.However,these three biopolymers are interwoven into a complex matrix in the lignocellulosic biomass,thus making it hard to quantify the contribution of each biopolymer.In this study,we selectively remove hemicellulose from switchgrass and investigate the effects of its diminishing concentration on the coefficient of friction.We observed that the angle of repose and,therefore,the coefficient of friction for a loose assembly of the control and treated switchgrass samples decrease with decreasing hemicellulose content.This indicates the frictional resistance to flow for biomass particulate assemblies is at least proportional to the hemicellulose content.We also established that the observed changes in the frictional behavior were not due to particle morphological characteristics. 相似文献