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181.
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Katarina Anđelković Dušan Sladić Alessia Bacchi Giancarlo Pelizzi Nenad Filipović Miloš Rajković 《Transition Metal Chemistry》2005,30(2):243-250
Complexes of zinc and iron with N, N2-bis[(1E)-1-(2-pyridyl)ethylidene]ethanedihydrazide (H2L1) and N ,N2-bis[(1E)-1-(2-pyridyl)ethylidene]propanedihydrazide (H2L2) were prepared. ZnII complexes with both ligands have an octahedral geometry. In the complex of ZnII with H2L1, the ligand is coordinated as a tridentate species in the monoanionic form, building two five-membered rings around ZnII. Three remaining coordination sites are occupied by water molecules, and in the outer sphere there is a ClO 4– ion. In the other ZnII complex, the H2L2 ligand is coordinated in the enol form as a tetradenate species, forming a five-memebered, a six-membered and a seven-membered ring, the remaining coordination sites being occupied by water molecules, while in the outer sphere there are two ClO 4– ions. The FeIII complex with H2L2 is a high-spin octahedral complex. The ligand is coordinated in the enol form, in a tetradentate fashion via pyridine and hydrazone nitrogens. The remaining two coordination sites in the complex are occupied by water molecules and a Cl– ion, and in the outer sphere there are two Cl– anions. The octahedral FeIII complex obtained from the reaction of FeCl3·6H2O and H2L1 in absolute ethanol has the formula [Fe(HL1)Cl2(H2O)]·1.5H2O. However, during coordination of the H2L1 ligand to FeIII in water, oxidative degradation of the side chain (–CO–CO–) and reduction of FeIII to FeII occurs, affording octahedral tris(1-(2-pyridyl)ethylidenehydrazine] ironII perchlorate, as confirmed by X-ray structure analysis. 相似文献
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Miloš Kopa Sebastiano Vitali Tomáš Tichý Radek Hendrych 《Computational Management Science》2017,14(4):559-583
This paper deals with implied volatility (IV) estimation using no-arbitrage techniques. The current market practice is to obtain IV of liquid options as based on Black–Scholes (BS type hereafter) models. Such volatility is subsequently used to price illiquid or even exotic options. Therefore, it follows that the BS model can be related simultaneously to the whole set of IVs as given by maturity/moneyness relation of tradable options. Then, it is possible to get IV curve or surface (a so called smile or smirk). Since the moneyness and maturity of IV often do not match the data of valuated options, some sort of estimating and local smoothing is necessary. However, it can lead to arbitrage opportunity if no-arbitrage conditions on state price density (SPD) are ignored. In this paper, using option data on DAX index, we aim to analyse the behavior of IV and SPD with respect to different choices of bandwidth parameter h, time to maturity and kernel function. A set of bandwidths which violates no-arbitrage conditions is identified. We document that the change of h implies interesting changes in the violation interval of moneyness. We also perform the analysis after removing outliers, in order to show that not only outliers cause the violation of no-arbitrage conditions. Moreover, we propose a new measure of arbitrage which can be considered either for the SPD curve (arbitrage area measure) or for the SPD surface (arbitrage volume measure). We highlight the impact of h on the proposed measures considering the options on a German stock index. Finally, we propose an extension of the IV and SPD estimation for the case of options on a dividend-paying stock. 相似文献
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We introduce the intermediate set as an interpolating solution concept between the core and the Weber set of a coalitional game. The new solution is defined as the limiting superdifferential of the Lovász extension and thus it completes the hierarchy of variational objects used to represent the core (Fréchet superdifferential) and the Weber set (Clarke superdifferential). It is shown that the intermediate set is a non-convex solution containing the Pareto optimal payoff vectors that depend on some chain of coalitions and marginal coalitional contributions with respect to the chain. A detailed comparison between the intermediate set and other set-valued solutions is provided. We compute the exact form of intermediate set for all games and provide its simplified characterization for the simple games and the glove game. 相似文献
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Ana Tačić Ivan Savić Vesna Nikolić Ivana Savić Snežana Ilić-Stojanović Dušica Ilić Slobodan Petrović Mirjana Popsavin Agnes Kapor 《Journal of inclusion phenomena and macrocyclic chemistry》2014,80(1-2):113-124
Sulfanilamide belongs to the group of drugs that have a bacteriostatic effect on different pathogenic microorganisms. This activity originates from the competitive antagonism with p-aminobenzoic acid, which is an integral part of folic acid. The safe use of sulfanilamide is limited due to poor solubility in the aqueous medium. Therefore, the aim of this paper is the synthesis of sulfanilamide, as well as preparing and structural characterization of its inclusion complexes with cyclodextrins. The crude sulfanilamide was obtained in the synthesis between acetanilide and chlorosulfonic acid according to the standard procedure. The synthesized sulfanilamide was recrystallized from water in order to obtain the satisfactory purity of the substance. Sufanilamide was complexed with β-cyclodextrin and 2-hydroxypropyl-β-cyclodextrin by the co-precipitation method. A molecular encapsulation of sulfanilamide was confirmed by using FTIR, 1H-NMR, XRD and DSC methods. Phase-solubility techniques were used to assess the formation of the inclusion complex between sulfanilamide and cyclodextrins. The photostability of sulfanilamide and its inclusion complexes was estimated by UVB irradiation in a photochemical reactor by applying the UV–Vis method. Based on the UV–Vis analysis, sulfanilamide:2-hydroxypropyl-β-cyclodextrin complex was presented as more photostable than sulfanilamide:β-cyclodextrin complex and sulfanilamide. The obtained results enable the potential use of these inclusion complexes for the preparation of oral formulations due to the enhanced solubility of sulfanilamide. 相似文献
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Jitka Dostálková Gita Procházková Vladimír Jirků Lucie Křiklavová Tomáš Lederer Miloslav Suchánek Tomáš Brányik 《Chemical Papers》2015,69(3):425-432
This paper focuses on the adhesion and biofilm formation potential of cellulolytic yeast Trichosporon cutaneum CCY 30-5-10 on solid cellophane from a novel perspective. First, physicochemical characterisation of the cells and carrier (cellophane) was performed to evaluate the effect of different culture media (complex vs mineral) on yeast cell adhesion. (Un)favourable adhesion conditions were predicted using the thermodynamic approach. Next, the ability of the cells to colonise the carrier under the above conditions was quantified and the biofilm structure was characterised using image analysis. The approaches described were found suitable to predict and experimentally verify favourable (cell-solid) adhesion, i.e. the hydrophobic and low electron-donor nature of cellophane together with hydrophobic cells (obtained when cultivated in a complex culture medium) were found to have a major impact in defining successful yeast adhesion with subsequent biofilm formation. 相似文献