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991.
Raphaël Loubère Pierre-Henri Maire Mikhail Shashkov Jérôme Breil Stéphane Galera 《Journal of computational physics》2010,229(12):4724-4761
We present a new reconnection-based arbitrary-Lagrangian–Eulerian (ALE) method. The main elements in a standard ALE simulation are an explicit Lagrangian phase in which the solution and grid are updated, a rezoning phase in which a new grid is defined, and a remapping phase in which the Lagrangian solution is transferred (conservatively interpolated) onto the new grid. In standard ALE methods the new mesh from the rezone phase is obtained by moving grid nodes without changing connectivity of the mesh. Such rezone strategy has its limitation due to the fixed topology of the mesh. In our new method we allow connectivity of the mesh to change in rezone phase, which leads to general polygonal mesh and allows to follow Lagrangian features of the mesh much better than for standard ALE methods. Rezone strategy with reconnection is based on using Voronoi tessellation. We demonstrate performance of our new method on series of numerical examples and show it superiority in comparison with standard ALE methods without reconnection. 相似文献
992.
We suggest a new algorithm for the solution of the time domain Maxwell equations in dispersive media. After spacial discretization we obtain a large system of time-convolution equations. Then this system is projected onto a small subspace consisting of the Laplace domain solutions for a preselected set of Laplace parameters. This approach is a generalization of the rational Krylov subspace approach for the solution of non-dispersive Maxwell’s systems. We show that the projected system preserves such properties of the initial system as stability and passivity. As an example we consider the 3D quasistationary induced polarization problem with the Cole–Cole conductivity model important for geophysical oil exploration. Our numerical experiments show that the introduction of the induced polarization does not have significant effect on convergence. 相似文献
993.
994.
Wavelength-tunable 100 fs pulses generated through the soliton self-frequency shift in a photonic-crystal fiber are employed to visualize femtosecond coherence and population relaxation dynamics in molecular aggregates by means of time-resolved sum-frequency generation. This technique reveals an ultrafast dephasing of coherent molecular excitations with a phase relaxation time of about 120 fs and resolves an ultrafast switching of the nonlinear-optical response of molecular aggregates. 相似文献
995.
Roman Kombarov Andrea Altieri Dmitry Genis Mikhail Kirpichenok Valeriy Kochubey Natalia Rakitina Zoya Titarenko 《Molecular diversity》2010,14(1):193-200
The analysis of known drugs (Comprehensive Medicinal Chemistry database (2008 version): ) and natural products (Koch et al., Proc Natl Acad Sci USA 102:17272–17277, 2008) has led to the identification of privileged
saturated and aromatic heterocyclic ring pairs that we have termed as “BioCores.” This article explains how the BioCores can
be used for the design of novel lead-like scaffolds. 相似文献
996.
Mikhail K. Volkov Eduard A. Kuraev Yury M. Bystritskiy 《Central European Journal of Physics》2010,8(4):580-586
The two-photon decay widths of scalar mesons σ(600), f 0(980) and a 0(980) as well a 0 → ju(ω)γ and f 0 → ju(ω)γ are calculated in the framework of the local Nambu-Jona-Lasinio model. The contributions of the quark loops (Hartree-Fock approximation) and the meson loops (next 1/N c -approximation where N c is the number of colors) are taken into account. The values of these contributions, as we show, are of the same order of magnitude. For the f 0 decay the K-loop contribution plays the dominant role. The results for two-gamma decays are in satisfactory agreement with modern experimental data. The predictions for a 0 → ju(ω)γ and f 0 → ju(ω)γ widths are given. 相似文献
997.
Bondarenko Darya S. Sheremet Mikhail A. Oztop Hakan F. Abu-Hamdeh Nidal 《Journal of Thermal Analysis and Calorimetry》2019,135(2):1095-1105
Journal of Thermal Analysis and Calorimetry - Convective flow and heat transfer in an alumina/water nanofluid enclosure having two centered adherent porous blocks under the effect of moving upper... 相似文献
998.
Nadezhda S. Baleeva Anastasia V. Khavroshechkina Elvira R. Zaitseva Ivan N. Myasnyanko Marina B. Zagudaylova Mikhail S. Baranov 《Tetrahedron letters》2019,60(34):150963
The active development of fluorescence microscopy requires an increase in the variety of the dyes and their characteristics. Compounds with a large Stokes shift, i.e., a large difference between the positions of the absorption and emission maxima, have attracted the interest of researchers as a tool that can be used for multicolor labeling. One of the known approaches to increase the Stokes shift is the introduction of additional polycyclic fragments. Herein, we report novel derivatives of a conformationally locked GFP chromophore containing the naphthalene ring. The proposed modification leads not only to the enhancement of the Stokes shift up to 100 nm but also leads to the noticeable red-shift of the emission and absorption spectra in contrast with the corresponding derivatives with one benzene ring. 相似文献
999.
Atoms and molecules can serve as sensitive probes of a possible variation of the fine structure constant α and electron‐to‐proton mass ratio μ. Two types of sensitivity coefficients are often used to quantify and compare the sensitivity of different species to the variation of fundamental constants. The dimensionless coefficients K are related to the fractional sensitivity, while dimensional factors q are related to the absolute sensitivity. Here, several common errors and misconceptions regarding these coefficients that frequently appear in the literature are discussed. 相似文献
1000.
Single-pixel imaging is an image reconstruction technique, which uses spatially modulated illumination of an object and a single-pixel detector collecting the light scattered by the object. This technique is complementary to the conventional imaging based on multipixel matrices and becomes especially interesting when one needs to go beyond the capabilities of the standard silicon-based sensors, e.g., to perform imaging in the infrared range. One of the factors that limit the resolution of the reconstructed images is the signal-to-noise ratio during the data acquisition. We propose several methods for processing the photodetector signal and develop a universal method to determine the optimal pixel number in light patterns with respect to illuminance of the object. We use these methods to capture the standard test images and discuss their advantages. 相似文献