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Artūras Dubickas 《Proceedings Mathematical Sciences》2005,115(4):391-397
Suppose that α > 1 is an algebraic number and ξ > 0 is a real number. We prove that the sequence of fractional partsξα
n
, n = 1, 2, 3, …, has infinitely many limit points except when α is a PV-number and ξ ∈ ℚ(α). For ξ = 1 and α being a rational
non-integer number, this result was proved by Vijayaraghavan. 相似文献
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Gediminas Braziulis Gytautas Janulevicius Ruta Stankeviciute Arturas Zalga 《Journal of Thermal Analysis and Calorimetry》2014,118(2):613-621
The preparation and characterization of the M′–Mo–O nitrate–tartrate (M′ = Mg, Ca, Sr, and Ba) gels, which were produced by the simple aqueous sol–gel method and calcined at 500, 600, 700, 800, 900, and 1,000 °C temperatures are reported. The crystalline alkaline earth metal molybdates (MgMoO4, CaMoO4, SrMoO4, and BaMoO4) and as-prepared M′–Mo–O nitrate–tartrate gels investigated by thermal analysis (TG/DSC), X-ray diffraction (XRD), and scanning electron microscopy (SEM). TG/DSC analysis showed the possible decomposition mechanism of synthesized gels. XRD studies allowed the identification of main types of crystalline structures in the MgMoO4, CaMoO4, SrMoO4, and BaMoO4 systems. Moreover, SEM analysis revealed the changes of surface morphology of the final compounds depending on annealing temperatures. 相似文献
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Juozas Kulys Heinz-Josef Deussen Kastis Krikstopaitis Palle Schneider Arturas Ziemys 《Monatshefte für Chemie / Chemical Monthly》2001,38(7):295-304
N-Aryl-N-hydroxy urethanes (AHUs), which are promising N*OH mediators for oxidoreductase catalysis, are electrochemically active redox compounds with a redox potential of 0.35–0.40 V vs. SCE (0.59–0.64 V vs. NHE). Alkyl substituents in the carbamic acid residue have, as expected, only little influence on the redox potential. The highest potential was noticed for N-hydroxy-N-(4-cyanophenyl)-carbamic acid methyl ester. Recombinant Coprinus cinereus peroxidase (rCiP) catalyzes oxidation of the AHUs with apparent bimolecular constants k ox of 2.5ċ104–7.5ċ104 M −1s−1 at pH = 8.5 and 25°C. Structure-function connectivities of the substrates were analysed within the framework of the Marcus cross relationship and by using ab initio quantum chemical calculations. An excellent correlation of the redox potentials and the HOMO energies could be found. However, no correlation of log(k ox) with redox potential and HOMO energy was indicated as predicted by theory. This was explained by specific docking of the substrates in the active center of rCiP. 相似文献
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A. Dubickas 《Lithuanian Mathematical Journal》1995,35(4):328-332
We give a lower bound for |α−1|, where α is an algebraic number, and also an upper bound for the number of real zeros of a
polynomial. A lower bound for the maximal modulus of conjugates of a totally real algebraic integer is also obtained.
Vilnius University, Naugarduko 24, 2006 Vilnius, Lithuania. Published in Lietuvos Matematikos Rinkinys, Vol. 35, No. 4, pp.
421–431, October–December, 1995. 相似文献
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Arturas Suchodolskis Vidmantas Feiza Arunas Stirke Ana Timonina Almira Ramanaviciene Arunas Ramanavicius 《Surface and interface analysis : SIA》2011,43(13):1636-1640
Chemical pretreatment is widely used to facilitate transformation of living cells when foreign components are introduced into a cell through the cell wall. The influence of appropriate chemicals on the wall properties and mechanism of transformation is still a matter of intensive studies. Saccharomyces cerevisiae cells (also known as baker's yeast) were investigated by atomic force microscopy (AFM). The cell walls were modified by lithium acetate and dithiothreitol. The AFM imaging was performed in liquid water‐based environment. The living cells were fixed by trapping into the holes of a polycarbonate membrane. Mechanical and morphological properties of initial intact cells and treated cells were investigated. The increased stiffness of the chemically treated cells was observed. As deduced from the applied theoretical Hertz‐Sneddon model, the treated cells show completely different response mechanism to applied mechanical pressure in comparison with the intact cells. Also, the increased roughness of the cell wall of the treated yeasts was observed. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
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Artūras Dubickas 《Czechoslovak Mathematical Journal》2006,56(3):949-956
We prove that every cyclic cubic extension E of the field of rational numbers contains algebraic numbers which are Mahler measures but not the Mahler measures of algebraic
numbers lying in E. This extends the result of Schinzel who proved the same statement for every real quadratic field E. A corresponding conjecture is made for an arbitrary non-totally complex field E and some numerical examples are given. We also show that every natural power of a Mahler measure is a Mahler measure. 相似文献