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131.
Ivan Argatov Alexei Iantchenko Vitaly Kocherbitov 《Continuum Mechanics and Thermodynamics》2017,29(6):1375-1387
A large amplitude oscillatory shear (LAOS) is considered in the strain-controlled regime, and the interrelation between the Fourier transform and the stress decomposition approaches is established. Several definitions of the generalized storage and loss moduli are examined in a unified conceptual scheme based on the Lissajous–Bowditch plots. An illustrative example of evaluating the generalized moduli from a LAOS flow is given. 相似文献
132.
133.
Irina N. Lushchakova Vitaly A. Strusevich 《European Journal of Operational Research》2010,200(2):334-346
The paper studies the problem of scheduling tasks on two machines to minimize the makespan. The tasks are assigned to the machine in advance. An incompatibility relation is defined over the tasks which forbids any two incompatible tasks to be processed at the same time. The problem can serve as a mathematical model for some batching problems in which the jobs are grouped in pairs on two machines. A linear-time algorithm is presented. 相似文献
134.
Alexander K. Popov Mikhail I. Shalaev Sergey A. Myslivets Vitaly V. Slabko 《Applied Physics A: Materials Science & Processing》2014,115(2):523-529
A possibility to greatly enhance frequency-conversion efficiency of stimulated Raman scattering is shown by making use of extraordinary properties of three-wave mixing of ordinary and backward waves. Such processes are commonly attributed to negative-index plasmonic metamaterials. This work demonstrates the possibility to replace such metamaterials that are very challenging to engineer by readily available crystals which support elastic waves with contra-directed phase and group velocities. The main goal of this work was to investigate specific properties of indicated nonlinear optical process in short-pulse regime and to show that it enables elimination of fundamental detrimental effect of fast damping of optical phonons on the process concerned. Among the applications is the possibility of creation of a family of unique photonic devices such as unidirectional Raman amplifiers and femtosecond pulse shapers with greatly improved operational properties. 相似文献
135.
The work presented is devoted to studies of foundations of the suppression techniques for electromagnetically induced instabilities of the free liquid metal surfaces. Such instabilities occur, for instance, in a number of technologies for requested refinement of materials like electron beam evaporation or levitation melting, in which the electromagnetic shaping technique is applied. The instability phenomenon in our case has following magnetohydrodynamic background. High-frequency magnetic field causes Lorentz force density generation within so-called skin-layer in the liquid metal, which works as a surface pressure in turn. With increase of the electromagnetic pressure a destabilizing mechanism progresses within the liquid metal domain, which causes a bifurcation. In this paper we discuss application alternating magnetic fields to increase the bifurcation threshold by passive and active redistribution of the Lorentz force density in the near-surface layers of the liquid metal domain. A novel stabilization system on the basis of a local electromagnetic influence on the liquid metal surface in the high frequency magnetic field is presented. The experimental results are discussed. (© 2011 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
136.
Buchachenko AL Ivanov VL Roznyatovsky VA Ustynyuk YA 《The journal of physical chemistry. A》2006,110(11):3857-3859
Photolysis of organotin molecules RSnMe3 is shown to be a spin selective radical reaction accompanied by fractionation of magnetic, (117,119)Sn, and nonmagnetic, (118,120)Sn, isotopes between starting reagents and products. A primary photolysis process is a homolytic cleavage of the C-Sn bond and generation of a triplet radical pair as a spin-selective nanoreactor. Nuclear spin dependent triplet-singlet conversion of the pair results in the tin isotope fractionation. Experimentally detected isotope distribution unambiguously demonstrates that the classical, mass-dependent isotope effect is negligible in comparison with magnetic, spin-dependent isotope effect. 相似文献
137.
Luu KN Phan AT Kuryavyi V Lacroix L Patel DJ 《Journal of the American Chemical Society》2006,128(30):9963-9970
We present the intramolecular G-quadruplex structure of human telomeric DNA in physiologically relevant K(+) solution. This G-quadruplex, whose (3 + 1) topology differs from folds reported previously in Na(+) solution and in a K(+)-containing crystal, involves the following: one anti.syn.syn.syn and two syn.anti.anti.anti G-tetrads; one double-chain reversal and two edgewise loops; three G-tracts oriented in one direction and the fourth in the opposite direction. The topological characteristics of this (3 + 1) G-quadruplex scaffold should provide a unique platform for structure-based anticancer drug design targeted to human telomeric DNA. 相似文献
138.
Cherenok S Vovk A Muravyova I Shivanyuk A Kukhar V Lipkowski J Kalchenko V 《Organic letters》2006,8(4):549-552
[structure: see text] Chiral calix[4]arene alpha-aminophosphonic acids were obtained through diastereoselective Pudovik-type addition of sodium ethyl phosphites to the chiral calixarene imines, removal of chiral auxiliary groups, and mild dealkylation of phosphonate fragments. The diacids obtained show inhibitory activity toward porcine kidney alkaline phosphatase that depends considerably on the absolute configuration of the alpha-carbon atoms. 相似文献
139.
Yury A. Sayapin Vitaly N. Komissarov Nadezhda I. Makarova Valery V. Tkachev Sergey M. Aldoshin 《Tetrahedron》2010,66(45):8763-8771
A series of novel derivatives of the 1,3-tropolone (β-tropolone) system—2-(2-quinolyl)-5,6,7-trichloro-1,3-tropolones and 2-(2-quinolyl)-4,5,6,7-tetrachloro-1,3-tropolones have been prepared by the acid-catalyzed reaction of 2-methylquinolines with 3,4,5,6-tetrachloro-1,2-benzoquinone. The molecular structures of two compounds, 2-(4-chloro-6,8-dimethyl-5-nitro-2-quinolyl)-5,6,7-trichloro-1,3-tropolone 8 and 2-(4-chloro-7,8-dimethyl-5-nitro-2-quinolyl)-4,5,6,7-tetrachloro-1,3-tropolone 9, have been determined using X-ray crystallography. According to the performed DFT B3LYP/6-311++G∗∗ calculations the tautomeric (OH) and (NH) forms of β-tropolones 8 and 9 are nearly energy equivalent, the latter being more stabilized in polar media. Photolysis of 2-(2-quinolyl)-1,3-tropolones in heptane solution leads to the disrotatory electrocyclic rearrangement resulting in the formation of a mixture of E- and Z-isomers of 3-[2(1H)-quinolinylyden]-bicyclo[3.2.0]hept-6-en-2,4-dione derivatives. 相似文献
140.