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41.
Sergey Y. Savinov Hwaung Lee Hyung Keun Song Byung-Ki Na 《Plasma Chemistry and Plasma Processing》2003,23(1):159-173
An experimental study of plasmachemical reaction involving CH4 and N2 molecules in rf discharge was studied in order to know the effect of vibrational excitation of N2 molecules. When the relative nitrogen concentration was greater than 0.8, the main product of CH4 decomposition was HCN, and the rate of methane decomposition at this condition was faster than that one in pure methane. These results could be confirmed through the mass spectroscopic method. The reason for these results is the vibrational energy of N2 excited by rf discharge. The chain reaction mechanisms of producing HCN by vibrational excitation of N2 were examined closely through numerical simulation. The rate-controlling step was the dissociation reaction of excited nitrogen molecule to the atomic nitrogen, so the process of HCN synthesis was limited by the value of reaction constant, kN. 相似文献
42.
Aleksandr A. Zirka Sergey I. Reshetnikov 《Reaction Kinetics and Catalysis Letters》2006,88(2):399-404
Summary Gas-phase hydrofluorination of perchloroethylene to pentafluoroethane in the presence of a chromium-magnesium catalyst at
0.4 MPa and 330-390°C has been studied. А reaction scheme taking into account the formation of by-products is suggested.
An erratum to this article is available at . 相似文献
43.
Donna C Arnold Olga Kazakova Guillaume Audoit Joseph M Tobin Jaideep S Kulkarni Sergey Nikitenko Michael A Morris Justin D Holmes 《Chemphyschem》2007,8(11):1694-1700
The synthesis of marokite CaMn(2)O(4) nanowires using a hydrothermal method is reported. Transmission electron microscopy and electron diffraction measurements show that the nanowires are polycrystalline in nature with diameters between 10 and 20 nm and lengths ranging from approximately 100 to 500 nm. Most interestingly, in contrast with the bulk material, magnetization measurements show that these nanowires exhibit ferromagnetic ordering with a Curie temperature (T(C)) of approximately 40 K. 相似文献
44.
Elena V. Piletska Maria Romero-Guerra Iva Chianella Kal Karim Anthony P.F. Turner Sergey A. Piletsky 《Analytica chimica acta》2005,542(1):111-117
The synthetic receptors for cocaine, deoxyephedrine, methadone and morphine were computationally designed and produced using molecular imprinting. The structure and energy of the molecular complexes were analysed by computational techniques. The possible structures of the binding sites in the synthetic receptors have been compared with those of corresponding natural receptors. The composition of imprinted polymers was optimised to allow adequate performance under the same experimental conditions. All selected molecular imprinting polymers (MIPs) demonstrated stronger affinity in comparison with corresponding blank polymers resulting in imprinted factors (I) equal to 1.2 (cocaine), 2.5 (deoxyephedrine), 3.5 (methadone) and 3 (morphine) which suggested that the specific binding site for each molecule was successfully created. The polymers studied possessed good selectivity and affinity towards their templates and could be recommended for the integration with sensor devices. From a practical point of view, especially for multisensor requirements, the synthetic receptors based on imprinted polymers could be superior to natural receptors due to their stability, robustness and compatibility with automation processes required for sensor fabrication. 相似文献
45.
The reactions of Ag-salts ofN-nitmhydroxyumines withN-methyl-N-chloromethylnitramine afford mainly products ofO-alkylation, whereas the reactions of the corresponding Li-, Na-, K-, Mg-, and NH4-sals in the presence of tetrabutylammonium (TBAB) give mainly products ofN-alkylation. The reactions of the corresponding. NH4-salts with bis-(chloromethyl)nitramine in the presence of TBAB lead solely to products ofO-alkylation. Increasing in the amount of TBAB results in the appearance of theN-isomer.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1740–1744, July, 1996. 相似文献
46.
4OR - Malaguti et al. introduce (Eur J Oper Res 273:874–888, 2019) the Fractional Knapsack Problem with Penalties, which is similar to the classical 0-1 Knapsack problem, except that each of... 相似文献
47.
Arutyunov Aram V. Zhukovskiy Evgeny S. Zhukovskiy Sergey E. Zhukovskaya Zukhra T. 《Set-Valued and Variational Analysis》2022,30(2):397-423
Set-Valued and Variational Analysis - The fixed points and coincidence points of mappings of v-metric spaces, i.e., sets on which a vector metric is defined, are investigated. The values of such a... 相似文献
48.
Kharitonov SV 《Analytical and bioanalytical chemistry》2005,382(7):1642-1651
The construction and electroanalytical response characteristics of poly(vinyl chloride) matrix ion-selective sensors (ISSs) for drotaverine hydrochloride are described. The membranes incorporate ion-association complexes of drotaverine with tetraphenylborate, picrate, tetraiodomercurate, tetraiodobismuthate, Reinecke salt, and heteropolycompounds of Keggin structure—molybdophosphoric acid, tungstophosphoric acid, molybdosiliconic acid and tungstosiliconic acid as electroactive materials for ionometric sensor controls. These ISSs have a linear response to drotaverine hydrochloride over the range 8×10–6 to 5×10–2 mol L–1 with cationic slopes from 51 to 58 mV per concentration decade. These ISSs have a fast response time (up to 1 min), a low determination limit (down to 4.3×10–6 mol L–1), good stability (3–5 weeks), and reasonable selectivity. Permeabilities and ion fluxes through a membrane were calculated for major and interfering ions. Dependences of the transport properties of the membranes on the concentrations of the ion exchanger and near-membrane solution and their electrochemical characteristics are presented. The ISSs were used for direct potentiometry and potentiometric titration (sodium tetraphenylborate) of drotaverine hydrochloride. Results with mean accuracy of 99.1±1.0% of nominal were obtained which corresponded well to data obtained by use of high-performance liquid chromatography. 相似文献
49.
Series of 3-arylalkyl- or 3-alkylamino-4-(indol-1-yl)maleimides and bis(indol-1-yl)maleimides were synthesised. The cyclization of the 3-substituted 4-(indol-1-yl)maleimides under the action of acids resulted in the formation of diazepine[1,4] derivatives with indoline and maleimide nuclei annelated. These compounds readily produced the corresponding indolomaleimidodiazepines[1,4] after dehydrogenation. 相似文献
50.
Anions formed from the lithiation of 1-(1-benzotriazolylalkyl)benzotriazoles (1, 6) and 1-(1-methylthioalkyl)benzotriazoles (10 and 10a) with n-BuLi underwent additions to cyclic and acyclic ketones giving intermediates 3a-f, 7b-f, and 11b-d, respectively, in excellent yields. Thermal rearrangements of intermediates 3a,b,d-f and 7b-d,f in the presence of zinc bromide provided one-carbon chain-extended or ring-expanded alpha-benzotriazolyl ketones 4a,b,d-f and 8b-d,f in moderate yields with excellent regioselectivity. By contrast, intermediates 11b-d on treatment with zinc bromide loose a molecule of benzotriazole followed by intramolecular cyclization of the resulting intermediates 12b-d to provide the 2,3- and 1,2,3-substituted indenes 13b-d in good yields. 相似文献