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51.
We prove a finiteness result for the number of solutions of a Diophantine equation of the form \(u_n u_{n+1}\cdots u_{n+k}\pm 1 =\pm u_m^2\), where \(\{ u_n\}_{n\ge 1}\) is a binary recurrent sequence whose characteristic equation has roots which are real quadratic units. 相似文献
52.
Sergio Albeverio Yuri Kondratiev Roman Nikiforov Grygoriy Torbin 《Bulletin des Sciences Mathématiques》2014
The paper is devoted to the study of fractal properties of subsets of the set of non-normal numbers with respect to Rényi f -expansions generated by continuous increasing piecewise linear functions defined on [0,+∞). All such expansions are expansions for real numbers generated by infinite linear IFS f={f0,f1,…,fn,…} with the following list of ratios Q∞=(q0,q1,…,qn,…). 相似文献
53.
Yuri?E.?GliklikhEmail author Olga?O.?Zheltikova 《Methodology and Computing in Applied Probability》2015,17(1):91-105
The paper is devoted to a brief introduction into the theory of equations and inclusions with mean derivatives and to investigation of a special type of such inclusions called inclusions of geometric Brownian motion type. The existence of optimal solutions maximizing some cost criteria, is proved. 相似文献
54.
Petr A. Obraztsov Anatoliy. A. Sirotkin Elena D. Obraztsova Yuri P. Svirko Sergey V. Garnov 《Optical Review》2010,17(3):290-293
We demonstrate the passive mode-locking of a diode-pumped Nd+3:YAG (central wavelength: 1.32 μm; pulse duration: 50 ps; output energy: up to 70 μJ) laser using a polymer film containing
single-wall carbon nanotubes. The mode-locking regime is stable at a pump repetition rate of up to 1 kHz. We also investigate
the temporal evolution of the light-induced absorption change of the polymer film containing carbon nanotubes in the spectral
range of 1.3–1.5 μm by femtosecond time-resolved pump-probe measurements. The measurements reveal that light-induced transmission
exhibits fast and slow components that last 280 fs and more than 10 ps, respectively. The third-order susceptibility of the
polymer film containing single wall carbon nanotubes is as high as 10−11 esu. 相似文献
55.
56.
Anton Shatskiy Konstantin D. Litasov Igor S. Sharygin Ilya A. Egonin Aleksandr M. Mironov Yuri N. Palyanov 《高压研究》2016,36(1):23-41
In order to constrain the Na2CO3–CaCO3–MgCO3 T–X diagram at 6?GPa in addition to the binary and pseudo-binary systems we conducted experiments along the Na2CO3–Ca0.5Mg0.5CO3 join. At 900–1000°C, melting does not occur and isothermal sections are presented by one-, two- and three-phase regions containing Ca-bearing magnesite, aragonite, Na2CO3 (Na2) and Na2(Ca1–0.9Mg0-0.1)3-4(CO3)4-5 (Na2Ca3-4), Na4(Ca1–0.6Mg0–0.4)(CO3)3 (Na4Ca), Na2(Ca0-0.08Mg1–0.92)(CO3)2 (Na2Mg) phases with intermediate compositions. The minimum melting point locates between 1000°C and 1100°C. This point would resemble that of three eutectics: Mgs–Na2Ca3–Na2Mg, Na2Mg–Na2Ca3–Na4Ca or Na2Mg–Na4Ca–Na2, in the compositional interval of [45Na2CO3·55(Ca0.6Mg0.4)CO3]–[60Na2CO3·40Ca0.6Mg0.4CO3]. The liquidus projection has seven primary solidification phase regions for Mgs, Dol, Arg, Na2Ca3, Na4Ca, Na2 and Na2Mg. The results suggest that extraction of Na and Ca from silicate to carbonate components has to decrease minimum melting temperature of carbonated mantle rocks to 1000–1100°C at 6?GPa and yields Na-rich dolomitic melt with a Na# (Na2O/(Na2O?+?CaO?+?MgO))?≥?28?mol%. 相似文献
57.
Setzpfandt F Sukhorukov AA Neshev DN Schiek R Kivshar YS Pertsch T 《Physical review letters》2010,105(23):233905
We study two-color parametric nonlinear modes in waveguide arrays with a quadratic nonlinear response. We predict theoretically and observe experimentally a new type of phase transition manifested in an abrupt power-controlled change of the mode structure from unstaggered to staggered, due to the interplay of localization and synchronization in parametrically driven discrete systems. 相似文献
58.
Valeriĭ Nikolaevich Berestovskiĭ Yuriĭ Gennadievich Nikonorov 《Annals of Global Analysis and Geometry》2014,45(3):167-196
In this paper, we develop new methods to study generalized normal homogeneous Riemannian manifolds. In particular, we obtain a complete classification of generalized normal homogeneous Riemannian metrics on spheres ${S^n}$ . We prove that for any connected (almost effective) transitive on $S^n$ compact Lie group $G$ , the family of $G$ -invariant Riemannian metrics on $S^n$ contains generalized normal homogeneous but not normal homogeneous metrics if and only if this family depends on more than one parameters and $n\ge 5$ . Any such family (that exists only for $n=2k+1$ ) contains a metric $g_\mathrm{can}$ of constant sectional curvature $1$ on $S^n$ . We also prove that $(S^{2k+1}, g_\mathrm{can})$ is Clifford–Wolf homogeneous, and therefore generalized normal homogeneous, with respect to $G$ (except the groups $G={ SU}(k+1)$ with odd $k+1$ ). The space of unit Killing vector fields on $(S^{2k+1}, g_\mathrm{can})$ from Lie algebra $\mathfrak g $ of Lie group $G$ is described as some symmetric space (except the case $G=U(k+1)$ when one obtains the union of all complex Grassmannians in $\mathbb{C }^{k+1}$ ). 相似文献
59.
Maxim N. Moskovsky Yuri H. Shogenov Alexander V. Lavrov Anatoly A. Gulyaev Igor Yu. Efremenkov Denis S. Pyatchenkov Mikhail V. Belyakov 《Photochemistry and photobiology》2023,99(1):29-34
We needed effective and sustainable technologies for better microbiological control of crops, including Fusarium. However, photoluminescent UV–Vis methods are potential for diagnosing plant diseases with Fusarium. It has not been sufficiently studied despite the application of these methods for other biological researches. The excitation spectrum of the seeds during infection shifts to the shorter wavelength and a new maximum appears in the region λ ≈ 232 nm. The photoluminescence of infected seeds increases with excitation by radiation of wavelengths λe,1 = 232 nm, λe,2 = 362 nm and λe,3 = 424 nm by 1.33–3.14 times, and λe,3 = 424 nm—decreases by 1.1 times. Statistical moments μ3 and μ4, asymmetry and kurtosis change only with short-wave excitation. When analyzing the decomposition of the frequency spectrum into Gaussian curves, the most informative ratio is the ratio of right-handed and left-handed Gaussians under excitation λe,2 = 362 nm and λe,3 = 424 nm. The ratios of their maxima change during infection by 1.36–3.2 times, and for excitation by radiation λe,2, the frequency boundaries of Gaussians change. The results of measurements and calculations provide a basis for the development of a method and device for photoluminescence diagnostics of fusarium seeds in UV–Vis ranges. 相似文献
60.
Lebedenko AN Guralchuk GY Sorokin AV Yefimova SL Malyukin YV 《The journal of physical chemistry. B》2006,110(36):17772-17775
Using fluorescent microscopy and microspectroscopy, optical properties and morphology transformations in individual pseudoisocyanine (PIC) J-aggregates in aqueous electrolyte solutions have been explored. A stringlike structure of J-aggregates with a string diameter much less than 1 microm has been observed. Photodestruction of the strings under short-wavelength excitation has been revealed. Rodlike PIC crystallites, about 1 microm in diameter, have been observed with time. The fluorescence spectrum of rodlike crystallites has been found to differ from that of stringlike J-aggregate and from PIC crystal powder spectra. The crystallites are very stable, and their photodestruction has not been observed under any excitation conditions. It has been found that rodlike crystallites in contrast to stringlike J-aggregates possess optical waveguide properties. The luminescence of crystallites can be observed only at the excitation spot and at butt ends located up to hundreds of micrometers from the excitation spot. 相似文献