排序方式: 共有49条查询结果,搜索用时 15 毫秒
11.
Douglas Bridges Hajime Ishihara Ray Mines Fred Richman Peter Schuster Luminiţa Vîţa 《Czechoslovak Mathematical Journal》2007,57(1):1-12
A weak form of the constructively important notion of locatedness is lifted from the context of a metric space to that of
a uniform space. Certain fundamental results about almost located and totally bounded sets are then proved. 相似文献
12.
Florentina Pătraşcu Mihaela Badea Maria Nicoleta Grecu Nicolae Stanică Luminiţa Măruţescu Dana Marinescu Cezar Spînu Cristian Tigae Rodica Olar 《Journal of Thermal Analysis and Calorimetry》2013,113(3):1421-1429
New species of type MLCl2·nH2O (M:Ni, n = 6; M:Cu, n = 1.5 and M:Zn, n = 1; L: 1,8-bis(3′-ketopyridil)-1,3,6,8,10,13-hexaazacyclotetradecane, ligand resulted by 1,2-diaminoethane, nicotinamide and formaldehyde template condensation) were synthesised. The compounds were characterised by chemical analysis, ESI–MS, IR, NMR, UV–Vis-NIR and EPR spectroscopy as well as magnetic data at room temperature. The modifications in the IR and NMR spectra are in accordance with the condensation process. Electronic spectra indicate that Ni(II) adopts an octahedral stereochemistry while the surrounding of Cu(II) is square-pyramidal. The proposed stereochemistry was furthermore confirmed by magnetic moments and EPR spectrum at room temperature. The water is eliminated in one or two steps, respectively, while the oxidative degradation of the ligand and chloride decomposition occur in two steps. The final residues consist of the most stable metallic oxides as X-ray powder diffraction indicates. The newly synthesised compounds were evaluated for their antimicrobial effect against different bacterial and fungal strains. 相似文献
13.
We present necessary and sufficient conditions for uniform exponential expansiveness of discrete skew-product flows, in terms of uniform complete admissibility of the pair (c 0(N, X), c 0(N, X)). We give discrete and continuous characterizations for uniform exponential expansiveness of linear skew-product flows, using the uniform complete admissibility of the pairs (c 0(N, X), c 0(N, X)) and (C 0(R +, X), C 0(R +, X)), respectively. We generalize an expansiveness theorem due to Van Minh, R?biger and Schnaubelt, for the case of linear skew-product flows. 相似文献
14.
We investigate separation properties for neighbourhood spaces in some details within a framework of constructive mathematics, and define corresponding separation properties for quasi‐apartness spaces. We also deal with separation properties for spaces with inequality. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
15.
16.
We present necessary and sufficient conditions for uniform exponential expansiveness of discrete skew-product flows, in terms
of uniform complete admissibility of the pair (c
0(N, X), c
0(N, X)). We give discrete and continuous characterizations for uniform exponential expansiveness of linear skew-product flows,
using the uniform complete admissibility of the pairs (c
0(N, X), c
0(N, X)) and (C
0(R
+, X), C
0(R
+, X)), respectively. We generalize an expansiveness theorem due to Van Minh, R?biger and Schnaubelt, for the case of linear skew-product
flows.
Received August 10, 2001; in revised form June 25, 2002 相似文献
17.
Georgescu Sergiu-Valeriu Coşereanu Camelia Fotin Adriana Brenci Luminiţa-Maria Costiuc Liviu 《Journal of Thermal Analysis and Calorimetry》2019,138(4):2505-2513
Journal of Thermal Analysis and Calorimetry - The research presented in this paper proposes structures of timber frame exterior walls using reed straws as insulation materials. Having thicknesses... 相似文献
18.
Adina Lumini?a Sasu Bogdan Sasu 《Journal of Mathematical Analysis and Applications》2011,380(1):17-32
We propose a new method for the study of the asymptotic behavior of difference equations in infinite-dimensional spaces, providing characterizations for the property of uniform exponential trichotomy. We deduce the structure of the stable, unstable and bounded subspace and prove the uniqueness of the projection families. We introduce a new admissibility concept with respect to a discrete input-output system and prove that this is a necessary and sufficient condition for the existence of uniform exponential trichotomy. Throughout the paper, there is no assumption on the coefficients and the obtained results are applicable to any class of difference equations. 相似文献
19.
The purpose of this paper is to give characterizations for uniform exponential dichotomy of evolution families on the real
line. We consider a general class of Banach function spaces denoted
and we prove that if
with
and the pair
is admissible for an evolution family
then
is uniformly exponentially dichotomic. By an example we show that the admissibility of the pair
for an evolution family is not a sufficient condition for uniform exponential dichotomy. As applications, we deduce necessary
and sufficient conditions for uniform exponential dichotomy of evolution families in terms of the admissibility of the pairs
and
with
相似文献
20.
Tito Lumini David N. Cox Raymond Roulet Gervais Chapuis Francesco Nicolo 《Helvetica chimica acta》1990,73(7):1931-1934
The complex [Ru(η5-C7H11)2H]BF4 (C7H11 = 2,4-dimethylpenta-2,4-dienyl) is highly reactive towards two- and six-electron ligands. e.g. giving with CO complex [RuCO(η4-C7H12)(η5-C7H11)]BF4. The 2,4-dimethylpenta-1,3-diene ligand (C7H12) of the latter complex is readily displaced giving, e.g. with excess cyclohexa-1,3-diene (C6H8) complex [RuCO(η4-C6H8)(η5-C7H11)]BF4. These reactions provide a convenient entry into monopentadienylruthenium chemistry. 相似文献