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排序方式: 共有122条查询结果,搜索用时 15 毫秒
81.
Ionela Alan Angela Kriza Mihaela Badea Nicolae Stanica Rodica Olar 《Journal of Thermal Analysis and Calorimetry》2013,111(1):483-490
New complexes of type [M(HL)(CH3COO)(OH2)m]·nH2O (where M:Co, m = 2, n = 2; M:Ni, m = 2, n = 1.5; M:Zn, m = 0, n = 2.5 and M:Cd, m = 0, n = 0; H2L:5-bromo-N,N′-bis-(salicylidene)-o-tolidine) have been synthesized and characterized by microanalytical, IR, UV–Vis-NIR and magnetic data. Electronic spectra of Co(II) and Ni(II) complexes are characteristic for an octahedral stereochemistry. The IR spectra indicate a chelate coordination mode for mono-deprotonated Schiff base and a bidentate one for acetate ion. The thermal transformations are complex according to TG and DTA curves including dehydration, acetate decomposition and oxidative degradation of the Schiff base. The final product of decomposition is the most stable metallic oxide. 相似文献
82.
The aim of this paper is to study the geometrical and topological structure of the efficient frontier of simply-shaded sets in a three-dimensional Euclidean space with respect to the usual positive cone. Our main result concerns the contractibility of the efficient frontier and refines a recent result of Daniilidis, Hadjisavvas, and Schaible (Ref. 1) regarding the connectedness of the efficient outcome set for three-criteria optimization problems involving continuous semistrictly quasiconcave objective functions. 相似文献
83.
Ilya Razdolski Ruslan R. Subkhangulov Diana G. Gheorghe Francis Bern Ionela Vrejoiu Alexey V. Kimel Andrei Kirilyuk Michael Ziese Theo Rasing 《固体物理学:研究快报》2015,9(10):583-588
Laser‐induced magnetisation dynamics of a La0.7Sr0.3MnO3/SrRuO3 superlattice is studied by means of a single‐colour optical pump‐probe technique. Significant differences in the magnetisation dynamics of a superlattice with respect to the single layers of constituent materials are demonstrated. Below the Curie temperature TC of SrRuO3, laser‐induced ultrafast demagnetisation is found to be followed by a uniform precession of the magnetisation around its new equilibrium. The data is described within a simple model based on a displacive excitation of a precessional magnetisation dynamics. The model is shown to give a good fit to the experimental data. As the initial temperature approaches TC, the oscillations get suppressed and eventually vanish. The magnetisation dynamics is shown to depend on whether the two distinct magnetisation vectors in the superlattice are ferromagnetically or antiferromagnetically aligned. (© 2015 WILEY‐VCH Verlag GmbH &Co. KGaA, Weinheim) 相似文献
84.
Alin Faur Claudia Watz Elena-Alina Moac tefana Avram Florin Borcan Iulia Pinzaru Andrada Iftode Mirela Nicolov Ramona Amina Popovici Marius Raica Camelia A. Szuhanek Cristina Dehelean 《Molecules (Basel, Switzerland)》2020,25(22)
The current study was aimed to evaluate the phenolic composition parameters of two hydro-alcoholic extracts of Ocimum basilicum L. (OB) obtained from the aerial part (without leaves) and leaves, in order to determine their contribution to the antioxidant activity (AOA). Both hydro-alcoholic extracts have proven to be rich in polyphenolic compounds, flavonoids, flavonols and tannins. Therefore, the leaves’ extracts reveal an inhibition percentage of 89%, almost comparable with the standard reference (95%). To complete the toxicological profile, the study also assessed the potential cytotoxicity of basil hydro-alcoholic extracts on immortalized human keratinocytes (HaCaT), skin human fibroblasts (1BR3), mice epidermis (JB6Cl41-5a) and primary human melanocytes (HEMa) cells, correlated to A375 antitumor in vitro activity. The extracts did not induce significant cytotoxic effect on any of the selected normal cell lines but showed relevant activity on A375 cells. Considering the low values obtained regarding the irritative effects in the chorionallantoic membrane of the egg on blood vessels, we can emphasize that both extracts can be considered as biocompatible ingredients. Regarding the potential activity of hydro-alcoholic extracts on human skin, the decrease of erythema values after the application of extracts was a relevant observation which indicates the anti-inflammatory potential of Ocimum basilicum L. 相似文献
85.
Ana Maria Popescu Elena Ionela Neacşu Kazimir Yanushkevich Virgil Constantin 《Surface and interface analysis : SIA》2014,46(6):378-386
Electroless Zn–Ni–P thin films were deposited on low carbon steel from an alkaline non‐cyanide aqueous electrolyte. The newly developed ternary alloys structure and microstructure investigations were carried out via X‐ray diffraction and SEM. Chemical composition of the coatings was investigated via energy dispersive spectroscopy. Polarization tests were used to study the corrosion properties of the coatings in a 3.5 wt.% NaCl solution. The results confirmed the high corrosion resistance of Zn–Ni–P alloy plated steel sheet. The surface analysis of the thin film samples before and after corrosion was performed by XPS. The incorporation of Zn in Ni–P thin film is proven for all initial samples to be as a mixture of zinc and zinc oxide, while nickel exists in +2 and +3 oxidized states. A passive film of a mixture of oxide and hydroxide of zinc and nickel forms on the surface and prevents the Zn–Ni–P thin films from corrosion. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
86.
Nicolae Popovici 《Journal of Global Optimization》2007,38(1):103-118
The principal aim of this paper is to extend some recent results concerning the contractibility of efficient sets and the
Pareto reducibility in multicriteria explicitly quasiconvex optimization problems to similar vector optimization problems
involving set-valued objective maps. To this end, an appropriate notion of generalized convexity is introduced for set-valued
maps taking values in a partially ordered real linear space, which naturally extends the classical concept of explicit quasiconvexity
of real-valued functions. Actually, the class of so-called explicitly cone-quasiconvex set-valued maps in particular contains
the cone-convex set-valued maps, and it is contained in the class of cone-quasiconvex set-valued maps.
相似文献
87.
Based on a high temperature hydrocarbon/heterogeneous atoms system of well-established composition, the formation of carbon nanostructures by laser-induced pyrolysis is related to the presence of heteroatoms in the reactants. In this paper, the goal is to underline the influence of some heteroatoms on the morphology and functionalizing nanostructured carbon materials by changing both gas composition and experimental parameters, with the focus to drive these materials into a regime where they can naturally interface with the surrounding matter. To investigate, in the versatile laser pyrolysis method, how to in situ modulate - through the presence of heterogeneous atoms - the characteristics of carbon nanopowders claimed by specific application is a challenge. Some preliminary results confirm experimentally their particular behavior during interaction with polymer matrices of some nanocomposites. 相似文献
88.
89.
We study, via Γ-convergence, the asymptotic behavior of several classes of power–law functionals acting on fields belonging
to variable exponent Lebesgue spaces and which are subject to constant rank differential constraints. Applications of the
Γ-convergence results to the derivation and analysis of several models related to polycrystal plasticity arising as limiting
cases of more flexible power–law models are also discussed. 相似文献
90.
Nicolae Popovici 《Operations Research Letters》2008,36(2):173-176
The principal aim of this paper is to show that every weakly efficient solution of a lexicographic quasiconvex multicriteria optimization problem actually is an efficient (Pareto) solution of a reduced problem, obtained from the original one by selecting a certain number of criteria, not exceeding the Helly number of the solution space. 相似文献