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21.
Maja Majerić Elenkov Mirjana Čičak Ana Smolko Anamarija Knežević 《Tetrahedron letters》2018,59(4):406-408
Biocatalytic ring-opening of epifluorohydrin has been performed by using halohydrin dehalogenase. The enzyme from Mycobacterium sp. GP1 (HheB2) catalysed reaction with high regioselectivity and low enantioselectivity in the presence of different nucleophiles, producing racemic 1-substituted 3-fluoro-2-propanols. No by-products resulting from the ring-closure reaction have been detected, confirming that vicinal fluoro alcohols are not substrates for HHDH. Four different 3-fluoro-2-propanols were prepared under mild reaction conditions starting from epifluorohydrin. High conversions of 85–100% were reached within 1–3?h and depending on the nucleophile used products were isolated in 31–92% yields. 相似文献
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We give numerical evidence that the two-dimensional nonequilibrium zero-temperature random field Ising model exhibits critical behavior. Our findings are based on the results of scaling analysis and collapsing of data, obtained in extensive simulations of systems with sizes sufficiently large to clearly display the critical behavior. 相似文献
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Svetlana Knežević R. Milačič Marjan Veber 《Analytical and bioanalytical chemistry》1998,362(1):162-166
A procedure was developed for the preconcentration and determination of aluminium and copper in dialysis concentrates at
the ng cm–3 level. The preconcentration was achieved on microcolumns filled with Chelex-100 resin adjusted to a pH of 4.0. Five repetitive
cycles of the sample through the column ensured a sufficient contact time for quantitative retention of aluminium and copper
ions. The retained ions were eluted with HNO3 (0.5 mol dm–3). Aluminium and copper were determined in the eluate by Zeeman ETAAS using the standard addition technique. The procedure
was performed under clean room conditions (class 10,000), The reliability of the results was evaluated by recovery tests,
using dialysis concentrates spiked with aluminium and copper. The recoveries obtained ranged from 86 to 106% for aluminium
and from 92 to 97% for copper. Using the recommended procedure, the LOD of aluminium and copper in dialysis concentrates (preconcentration
factor 2) was found to be 0.5 ng cm–3 and 0.2 ng cm–3, respectively.
Received: 19 December 1997 / Revised: 10 March 1998 / Accepted: 28 March 1998 相似文献
25.
Kuzmanović Predrag Todorović Nataša Nikolov Jovana Knežević Jovana Miljević Bojan 《Journal of Radioanalytical and Nuclear Chemistry》2020,323(2):861-874
Journal of Radioanalytical and Nuclear Chemistry - This paper presents the results of the gamma spectrometric analysis of 27 raw materials used for the production of ceramic tiles in Serbia and 9... 相似文献
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Kuzmanović Predrag Todorović Nataša Filipović Petrović Leposava Mrđa Dušan Forkapić Sofija Nikolov Jovana Knežević Jovana 《Journal of Radioanalytical and Nuclear Chemistry》2020,324(3):1077-1087
Journal of Radioanalytical and Nuclear Chemistry - This paper presents a gamma spectrometric analysis of 47 samples of building materials produced and used in Serbia. Based on the measured activity... 相似文献
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Miljan Kne?evi? Miodrag Mateljevi? 《Journal of Mathematical Analysis and Applications》2007,334(1):404-413
We prove versions of the Ahlfors-Schwarz lemma for quasiconformal euclidean harmonic functions and harmonic mappings with respect to the Poincaré metric. 相似文献
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J. Knežević-Miljanović 《Differential Equations》2009,45(2):267-270
We consider the equation y″ = P(x)x a y σ , σ < 0, and prove the unique solvability of the Cauchy problem y(0) = 0, y′(0) = λ. 相似文献
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Sunčica Elezović-Had zić Milan Kne zević Sava Milošević Ivan Zivić 《Journal of statistical physics》1996,83(5-6):1241-1253
We study the problem of polymer adsorption in a good solvent when the container of the polymer-solvent system is taken to be a member of the Sierpinski gasket (SG) family of fractals. Members of the SG family are enumerated by an integerb (2b), and it is assumed that one side of each SG fractal is an impenetrable adsorbing boundary. We calculate the critical exponents 1, 11, and
s
, which, within the self-avoiding walk model (SAW) of the polymer chain, are associated with the numbers of all possible SAWs with one, both, and no ends anchored to the adsorbing impenetrable boundary, respectively. By applying the exact renormalization group (RG) method for 2b8 and the Monte Carlo renormalization group (MCRG) method for a sequence of fractals with 2b80, we obtain specific values for these exponents. The obtained results show that all three critical exponents 1, 11, and
s
, in both the bulk phase and crossover region are monotonically increasing functions withb. We discuss their mutual relations, their relations with other critical exponents pertinent to SAWs on the SG fractals, and their possible asymptotic behavior in the limitb, when the fractal dimension of the SG fractals approaches the Euclidean value 2. 相似文献