排序方式: 共有67条查询结果,搜索用时 15 毫秒
61.
Goong Chen Tingwen Huang Maria Christina Mariani Roza Espandeary Rym Kanes Mohammed Sheriff Srikanth Srinivasan 《Physica A》2013
The Fourier spectrum of a curve on a given interval, as represented by the Fourier series, is very reflective of the oscillatory behavior of the curve as the “weights” of the Fourier coefficients can indicate the individual prominence of frequencies of oscillations. But, unfortunately, the calculations of the Fourier coefficients can often get quite cumbersome. 相似文献
62.
Reactions of 1-Aminoalkane-1,1-diphosphonic Acids with Nitrous Acid Compounds of the structure RC(NH2)(PO3H2)2 1 give products RC(OH)(PO3H2)2 2 in high yields by the reaction with nitrous acid. In contrast, when R = Aryl the reaction of 1 often gives in concentrated hydrochloric acid RCCl(PO3H2)2 3 . Exceptions to the above reaction are described. 相似文献
63.
Synthesis of the diamide 2 derived from tris(2-aminoethyl)amine and monocarboxymethylcalix[4]arene provides a starting material useful for the preparation of a variety of hyperbranched molecules. Metal ion binding is one of the potentially useful properties of these new materials. 相似文献
64.
For p > 1, we establish existence and asymptotic behavior of a positive continuous solution to the following boundary value problem $$\left\{\begin{array}{ll}\frac{1}{A} \left( A\Phi _{p}(u^{\prime})\right) ^{\prime}+a_{1}(r)u^{\alpha _{1}}+a_{2}(r)u^{\alpha _{2}}=0, \, {\rm in}\, (0,\infty ),\\ {\rm lim}_{r\rightarrow 0} A\Phi _{p}(u^{\prime})(r)=0, {\rm lim}_{r\rightarrow \infty } u(r)=0,\end{array}\right.$$ where \({\alpha _{1}, \alpha _{2} < p -1, \Phi _{p}(t) = t|t| ^{p-2},A}\) is a positive differentiable function and a 1, a 2 are two positive functions in \({C_{\rm loc}^{\gamma}((0, \infty )), 0 < \gamma < 1,}\) satisfying some appropriate assumptions related to Karamata regular variation theory. Also, we obtain an uniqueness result when \({\alpha _{1}, \alpha _{2} \in (1-p,p-1)}\) . Our arguments combine a method of sub and supersolutions with Karamata regular variation theory. 相似文献
65.
Rym Chemmam Habib Mâagli Syrine Masmoudi 《Nonlinear Analysis: Theory, Methods & Applications》2011,74(5):1555-1576
The purpose of this paper is to extend some results of the potential theory of an elliptic operator to the fractional Laplacian (−Δ)α/2, 0<α<2, in a bounded C1,1 domain D in Rn. In particular, we introduce a new Kato class Kα(D) and we exploit the properties of this class to study the existence of positive solutions of some Dirichlet problems for the fractional Laplacian. 相似文献
66.
Ildikó Mohammed-Ziegler Abdelwaheb Hamdi Rym Abidi Jacques Vincens 《Supramolecular chemistry》2013,25(3):219-234
Abstract Dibenzo-14-crown-4 alcohols are shown to aggregate in chloroform by the formation of hydrogen-bonded dimers. Structural variations between crown ether alcohols significantly affect the degree of dimerization. This self-association is of relevance for understanding the complexation and extractive properties of these and related macrocycles. 相似文献
67.
Abdelwaheb Hamdi Mohamed Habib Noomen Rym Abidi A. Rim Woo Jeong Hwan Cho Yang Kim 《Journal of inclusion phenomena and macrocyclic chemistry》2011,71(3-4):287-291
The synthesis and complexation properties of three new derivatives, one spirobiscalix[4]azacrown (1) and two calix[4]azacrown (2 and 3), are reported. Complexation studies of the three ligands toward transition and heavy metal cations have been carried out and monitored by UV absorption spectrophotometry in acetonitrile. Mononuclear complexes were detected for all complexes, whereas binuclear species (M2L) were also formed in the case of ligand 1 with Cu2+ and Pb2+. The extraction properties of 1, 2 and 3 toward Cu2+, Zn2+, Pb2+, Ag2+ and Cd2+ are also reported. The results showed that complexation is the main factor affecting extraction with ligands 2 and 3, while with ligand 1 it is not. 相似文献