Institution
National Academy of Sciences of Ukraine
Government•Kyiv, Ukraine•
About: National Academy of Sciences of Ukraine is a government organization based out in Kyiv, Ukraine. It is known for research contribution in the topics: Adsorption & Magnetic field. The organization has 46422 authors who have published 59466 publications receiving 573466 citations. The organization is also known as: Natsional’na akademiya nauk Ukrayiny & NAN Ukraine.
Topics: Adsorption, Magnetic field, Nonlinear system, Catalysis, Electron
Papers published on a yearly basis
Papers
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TL;DR: The results reveal that the Tl1-xIn-xSnxSe2 single-crystal surface is sensitive to the Ar(+) ion irradiation that induced structural modification in the top surface layers.
Abstract: Photoelectrical properties of Tl1−xIn1−xSnxSe2 single crystalline alloys (x = 0, 0.1, 0.2, 0.25) grown using the Bridgman–Stockbarger method were studied. The temperature dependence of electrical and photoconductivity for the Tl1−xIn1−xSnxSe2 single crystals was explored. It has been established that photosensitivity of the Tl1−xIn1−xSnxSe2 single crystals increases with x. The spectral distribution of photocurrent in the wavelength spectral range 400–1000 nm has been investigated at various temperatures. Photoconductivity increases in all the studied crystals with temperature. Therefore, thermal activation of photoconductivity is caused by re-charging of the photoactive centers as the samples are heated. Based on our investigations, a model of center re-charging is proposed that explains the observed phenomena. X-ray photoelectron valence-band spectra for pristine and Ar+-ion irradiated surfaces of the Tl1−xIn1−xSnxSe2 single crystals have been measured. These results reveal that the Tl1−xIn1−xSnxSe2 single-crystal surface is sensitive to the Ar+ ion irradiation that induced structural modification in the top surface layers. Comparison on a common energy scale of the X-ray emission Se Kβ2 bands representing energy distribution of the Se 4p-like states and the X-ray photoelectron valence-band spectra was done.
163 citations
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TL;DR: It was found that colloid ceria solutions are non-toxic to mouse fibroblasts and fibroblast-like cells of African Green monkey and ceria nanoparticles are capable to protect these cells from UV-irradiation-induced damage.
Abstract: UV-shielding property, photocatalytic activity and cytotoxicity (including photocytotoxicity) of citrate-stabilized ceria colloid solutions were studied. It was established that UV-shielding property (namely, the sun protection factor, the critical absorption wavelength and the UVA/UVB-ratio) of ceria nanoparticles are as good as those of titanium dioxide and zinc oxide nanoparticles. It was further demonstrated that ceria nanoparticles possesses substantially lower photocatalytic activity, which additionally decreases upon decrease in ceria particle size. It was found that colloid ceria solutions are non-toxic to mouse fibroblasts (L929) and fibroblast-like cells of African Green monkey (VERO). Moreover, ceria nanoparticles are capable to protect these cells from UV-irradiation-induced damage. It was proposed that nanocrystalline ceria could be used not only as UV-blocking material, but also as prophylactic and even therapeutic compound for sunburns treatment.
163 citations
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TL;DR: The conformational features of the mitotic kinesin Eg5 inhibitor monastrol were investigated by computational (AM1, HF/3-21G∗), X-ray diffraction, and NMR studies as discussed by the authors.
162 citations
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TL;DR: In this article, a review of the properties of superconductors with competing electron spectrum instabilities, namely, charge-density waves (CDWs) and spin-density wave (SDWs), is presented.
Abstract: This review deals with the properties of superconductors with competing electron spectrum instabilities, namely, charge-density waves (CDWs) and spin-density waves (SDWs). The underlying reasons of the electron spectrum instability may be either Fermi surface nesting or the existence of Van Hove saddle points for lower dimensionalities. CDW superconductors include layered dichalcogenides, NbSe3, and compounds with the A15 and C15 structures among others. There is much evidence to show that high-Tc oxides may also belong to this group of materials. The SDW superconductors include URu2Si2 and related heavy-fermion compounds, Cr-Re alloys and organic superconductors. We review the experimental evidence for CDW and SDW instabilities in a wide range of different superconductors, and assess the competition between these instabilities of the Fermi surface and the superconducting gap. Issues concerning the superconducting order parameter symmetry are also touched upon. The accent is put on establishing a universal framework for further theoretical discussions and experimental investigations based on an extensive list of available and up-to-date references.
162 citations
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TL;DR: The EMma technique has three advantages over conventional GFAAS: first, no sample dissolution is required; second, several elements of interest are determined simultaneously; and third, the EMMA technique is not subject to matrix interferences.
Abstract: An Energy-dispersive Miniprobe Multielement Analyzer (EMMA) was designed and constructed for sensitive, rapid, and non-destructive analysis of trace elements (As, Cr, Cu, Fe, Ga, Ge, Hf, Mn, Ni, Pb, Rb, Se, Sr, Th, Y, U, Zn) in small (e.g. 50 μm) samples such as individual mineral grains from rocks. An alternative configuration of the EMMA instrument is described here for use with larger samples such as powders of coal, soil, sediments, and plant materials. To minimize heterogeneity problems, a larger X-ray beam size (0.1 × 6 mm) was used by installing a different collimator, and the sample holder rotated 25 times per minute. Using this approach, Rb, Sr, Cu, Zn and Pb were measured in peat samples collected from bogs in Switzerland and northern Scotland. The detection limit for Pb, for example, is approximately 0.3 μg/g which is one order of magnitude better than conventional XRF analyzers. For comparison, Pb was also measured in acid digests of the same samples using GFAAS. The Pb results obtained using EMMA are comparable to the GFAAS data for the continental peat samples. However, in the Cl-rich samples from the maritime bogs, the GFAAS signal was strongly suppressed, and an accurate comparison of the two methods was not possible. The EMMA technique, therefore, has three advantages over conventional GFAAS: first, no sample dissolution is required; second, several elements of interest are determined simultaneously; and third, the EMMA technique is not subject to matrix interferences.
162 citations
Authors
Showing all 46484 results
Name | H-index | Papers | Citations |
---|---|---|---|
Yury Gogotsi | 171 | 956 | 144520 |
Alexander Belyaev | 142 | 1895 | 100796 |
Sergey Burdin | 131 | 1283 | 91273 |
Sercan Sen | 126 | 1119 | 65021 |
Yuri S. Kivshar | 126 | 1845 | 79415 |
Thomas E. Mallouk | 122 | 549 | 52593 |
Donal D. C. Bradley | 115 | 652 | 65837 |
Gao Qing Lu | 108 | 546 | 53914 |
Markus Roth | 99 | 1030 | 40499 |
Nikolay I. Zheludev | 97 | 812 | 35434 |
Valery Pugatch | 92 | 977 | 39993 |
Michael V. Swain | 91 | 739 | 31167 |
Alexei Verkhratsky | 89 | 450 | 29788 |
Edward A. Clark | 85 | 279 | 23341 |
Michael I. Mishchenko | 85 | 388 | 27576 |