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31.
V. Nikiforov 《Journal of Mathematical Sciences》2012,182(2):164-174
In recent years, the trace norm of graphs has been extensively studied under the name graph energy. In this paper, this research is extended to more general matrix norms, for example, the Schatten p-norms and the Ky Fan k-norms. Whenever possible, the results are given both for graphs and general matrices. In various contexts, a puzzling fact was observed: the Schatten p-norms are widely different for 1????p?<?2 and for p????2. 相似文献
32.
N. De Geyter A. Sarani T. Jacobs A. Yu. Nikiforov T. Desmet P. Dubruel 《Plasma Chemistry and Plasma Processing》2013,33(1):165-175
In this work, poly-ε-caprolactone samples are modified by an atmospheric pressure plasma jet in pure argon and argon/water vapour mixtures. In a first part of the paper, the chemical species present in the plasma jet are identified by optical emission spectroscopy and it was found that plasmas generated in argon/0.05 % water vapour mixtures show the highest emission intensity of OH (A–X) at 308 nm. In a subsequent section, plasma jet surface treatments in argon and argon/water vapour mixtures have been investigated using contact angle measurements and X-ray photoelectron spectroscopy. The polymer samples modified with the plasma jet show a significant decrease in water contact angle due to the incorporation of oxygen-containing groups, such as C–O, C=O and O–C=O. The most efficient oxygen inclusion was however found when 0.05 % of water vapour is added to the argon feeding gas, which correlates with the highest intensity of OH (X) radicals. By optimizing the OH (X) radical yield in the plasma jet, the highest polymer modification efficiency can thus be obtained. 相似文献
33.
Alexander Grechnikov Sergey Nikiforov Kerstin Strupat Alexander Makarov 《Analytical and bioanalytical chemistry》2014,406(13):3019-3023
A surface-assisted laser desorption/ionization (SALDI) source is coupled to the Orbitrap mass analyzer; the instrumental approach is tested for the analysis of rhenium (Re) and osmium (Os) complexes with 8-mercaptoquinoline. Silicon (Si) material obtained by laser treatment of monocrystalline Si is used as SALDI substrate. All studied complexes are detected as radical cations, with no protonated molecules. The comparison of SALDI, matrix-assisted laser desorption/ionization (MALDI), and direct laser desorption/ionization (LDI) on metal plates in the same instrumental setup demonstrated that the detection of the studied complexes using SALDI provides the highest sensitivity. The ability to analyze samples rapidly, high purity of spectra, and good analytical parameters make SALDI coupled to the Orbitrap mass analyzer a potentially powerful tool for the detection of Re and Os complexes and related organic, UV-absorbing compounds. Figure
? 相似文献
34.
Egor A. Kapitonov Natalia N. Petrova Vasilii V. Mukhin Leonid A. Nikiforov Vladimir D. Gogolev Ee Le Shim Aitalina A. Okhlopkova Jin-Ho Cho 《Molecules (Basel, Switzerland)》2021,26(4)
The physical and mechanical properties of nitrile–butadiene rubber (NBR) composites with N-cetylpyridinium bromide-carbon black (CPB-CB) were investigated. Addition of 5 parts per hundred rubber (phr) of CPB-CB into NBR improved the tensile strength by 124%, vulcanization rate by 41%, shore hardness by 15%, and decreased the volumetric wear by 7% compared to those of the base rubber-CB composite. 相似文献
35.
Nikiforov I. V. Deyneko D. V. Duskaev I. F. Lazoryak B. I. 《Journal of Structural Chemistry》2021,62(10):1621-1630
Journal of Structural Chemistry - Phosphates Ca9Gd1–xTbx(PO4)7 with whitlockite structure are prepared for the first time by the solid-phase method. The obtained compounds are studied by a... 相似文献
36.
Physics of the Solid State - Phosphate solid solutions based on the whitlockite family Ca9 – xMxDy(PO4)7 (M = Zn2+ or Mg2+) have been obtained. The samples have been... 相似文献
37.
On the basis of experimental data obtained in uniaxial and symmetrical and nonsymmetrical biaxial tension and pure shear, the deformation behavior of unfilled and filled butadiene-nitrile rubbers is described by means of the Bartenev-Khazanovich one-parameter high-elastic potential.Leningrad Branch of the Scientific-Research Institute of the Rubber Industry. Translated from Mekhanika Polimerov, No. 2, pp. 363–366, March–April, 1972. 相似文献
38.
39.
A. I. Yakimov A. V. Dvurechenskii V. V. Kirienko A. I. Nikiforov 《Physics of the Solid State》2005,47(1):34-37
Photodetectors based on Ge/Si multilayer heterostructures with germanium quantum dots are fabricated for use in fiber-optic communication lines operating in the wavelength range 1.30–1.55 μm. These photodetectors can be embedded in an array of photonic circuit elements on a single silicon chip. The sheet density of germanium quantum dots falls in the range from 0.3 × 1012 to 1.0 × 1012 cm?2, and their lateral size is approximately equal to 10 nm. The heterostructures are grown by molecular-beam epitaxy. For a reverse bias of 1 V, the dark current density reaches 2 × 10?5 A/cm2. This value is the lowest in the data on dark current densities available in the literature for Ge/Si photodetectors at room temperature. The quantum efficiency of photodiodes and phototransistors subjected to illumination from the side of the plane of the p-n junctions is found to be 3% at a wavelength of 1.3 μm. It is demonstrated that the maximum quantum efficiency is achieved for edge-illuminated waveguide structures and can be as high as 21 and 16% at wavelengths of 1.3 and 1.5 μm, respectively. 相似文献
40.
V. G. Nikiforov G. M. Safiullin A. G. Shmelev A. V. Leontev V. S. Lobkov 《JETP Letters》2007,86(10):666-669
The control of the anisotropy of the orientation of molecules in pure 1,2-dichlorobenzene, C6H4Cl2 at room temperature is demonstrated experimentally. To accomplish the optical control, the medium is exposed to non-resonant
excitation with two successive linearly polarized laser pulses with a duration of 60 fs. The state of transient anisotropy
is probed with the third pulse by detecting the ultrafast optical Kerr effect via optical heterodyne detection and synchronous
demodulation. It is shown that variations in the two parameters, the delay time between two pump pulses, and the angle between
the polarization directions of the pump pulses ensure the control of the anisotropy of the orientation of molecules in the
subpicosecond region.
Original Russian Text ? V.G. Nikiforov, G.M. Safiullin, A.G. Shmelev, A.V. Leont’ev, V.S. Lobkov, 2007, published in Pis’ma
v Zhurnal éksperimental’noĭ i Teoreticheskoĭ Fiziki, 2007, Vol. 86, No. 10, pp. 757–761. 相似文献