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131.
132.
Yurii A. Aleshchenko Vladimir V. Kapaev Yurii V. Kopaev 《Journal of Russian Laser Research》2010,31(6):533-553
We review our study aimed at the creation of a unipolar laser with the efficient suppression of nonradiative relaxation between
the laser subbands owing to strongly asymmetric-in-height barriers surrounding an active element. The asymmetry of the barriers
causes the existence of a lower laser subband only within a narrow region of in-plane momenta. In such a way, one-phonon relaxation
between the laser subbands can be significantly suppressed. 相似文献
133.
Yana I. Sakhno Svetlana V. Shishkina Oleg V. Shishkin Vladimir I. Musatov Elena V. Vashchenko Sergey M. Desenko Valentin A. Chebanov 《Molecular diversity》2010,14(3):523-531
Heterocyclization reactions of pyruvic acids, aromatic aldehydes and 5-amino-N-aryl-1H-pyrazole-4-carboxamides yielding four different types of final compounds are described. The reactions involving arylidenpyruvic
acids lead with high degree of selectivity to either 4,7-dihydropyrazolo[1,5-a]pyrimidine-5-carboxylic acids or 5-[(2-oxo-2,5-dihydrofuran-3-yl)amino]-1H-pyrazoles, depending on the catalyst type or temperature regime. The interactions based on arylpyruvic acids can take place
under kinetic or thermodynamic control producing 7-hydroxy-4,5,6,7-tetrahydropyrazolo[1,5-a]pyrimidine-7-carboxylic acids or 3-hydroxy-1-(1H-pyrazol-5-yl)-1,5-dihydro-2H-pyrrol-2-ones, respectively. 相似文献
134.
Vladimir Petukhov John Stoemenos Johan Rothman Andrey Bakin Andreas Waag 《Applied Physics A: Materials Science & Processing》2011,102(1):161-168
In order to interpret results of temperature dependent Hall measurements in heteroepitaxial ZnO-thin films, we adopted a multilayer
conductivity model considering carrier-transport through the interfacial layer with degenerate electron gas as well as the
upper part of ZnO layers with lower conductivity. This model was applied to the temperature dependence of the carrier concentration
and mobility measured by Hall effect in a ZnO-layer grown on c-sapphire with conventional high-temperature MgO and low-temperature
ZnO buffer. We also compared our results with the results of maximum entropy mobility-spectrum analysis (MEMSA). The formation
of the highly conductive interfacial layer was explained by analysis of transmission electron microscopy (TEM) images taken
from similar layers. 相似文献
135.
Vladimir Fal’ko Andre Geim Sankar Das Sarma Allan MacDonald Philip Kim 《Solid State Communications》2009,149(27-28):1039-1040
136.
The drive belt set on two pulleys is considered as a plane elastic rod. The nonlinear theory of rods with tension is used. The static frictionless contact problem for the rod is formulated. The derived boundary value problem for the nonlinear ordinary differential equations is solved by the finite difference method and by the shooting method by means of computer mathematics. The belt shape and the stresses are determined. The contact reaction and the contact area are obtained in the solution. A benchmark study of extensible and inextensible models is performed. (© 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
137.
Il'yas Nizamov Vladimir Al'fonsov Elvira Batyeva 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1-4)
Abstract The use of iodine results in reactivity enhancement of phosphorus sulfides and homologues of Davy's reagent in the reactions with disulfides, aminals and thioacetals. The reactions β-diiodotetraphosphorus trisulfides with disulfides, aminals and thioacetals were studied. 相似文献
138.
Vladimir I. Galkin Gulchira M. Saakyan Irina V. Galkina Rafael A. Cherkasov 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1-4)
Abstract Elaboration of effective methods of selective phosphorylation of α,β-unsaturated carbonyl compounds containing simultaneously C[dbnd]C and C[dbnd]O bonds, which may compete with each other or react consistently one after another, is one of the most complex problems in the modern organophosphorus synthesis. On the basis of our previous systematic investigations of kinetics and mechanism of the Pudovik and Abramov reactions in the series of α,β-unsaturated carbonyl compounds we have suggested three possible ways to solve this problem: a) soft reaction conditions, regulated by solvent, catalyst and temperature; b) interface catalysis; c) metallocomlex catalysis (reaction in the coordination sphere of transition metal). 相似文献
139.
140.
Valery Kukhar Vladimir Solodenko Vadim Soloshonok Tamara Kasheva 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1-4):529-532
Abstract Synthesis of enantiomeric amino phosphonic acids APA is described by using chiral auxiliary reagent or enzymatic resolution of racemic mixtures of APA phenacyl derivatives. Peptides with APA residue were obtained by application of trimethylsilyl derivatives or condensation in the presence of enzyme-papain 相似文献