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Kh. Z. Brainina Leonid G. Galperin Еkaterina V. Vikulova Natalia Yu. Stozhko Аidar M. Murzakaev Оlga R. Timoshenkova Yuri А. Kotov 《Journal of Solid State Electrochemistry》2011,15(5):1049-1056
The article presents the findings of microscopic and electrochemical studies of size-dependent gold particles electrooxidation.
Gold particles were immobilized on the surface of carbon-containing screen-printed electrodes. The experiment demonstrated
that the transition from macroparticles to nanoparticles caused a shift of the maximum current potential of gold oxidation
into the area with more negative potentials. A decrease in particle size resulted in an increase in the electrochemical activity
of metal. A positive correlation between experimental and calculated curves confirms a mathematical model (2) and correctness of the calculations. Measured parameters of voltammograms, in particular, maximum current potential, can
be used to describe the electrochemical activity and energy properties of nanoparticles. 相似文献
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Г. С. Белսкоɞа Л. М. Беляеɞ Б. А. Беиечкսŭ 《Isotopes in environmental and health studies》2013,49(4):133-135
Organische gebundener Stickstoff bzw. Sauerstoff kann mit geeigneten Reagenzien über NH3 bzw. H2O an Jod, Phosphor, Kohlenstoff oder Waserstoff homöopolar gebunden werden. Dabei sollten Substanzen entstehen, die sich zur IR-spektralphotometrischen Analyse eignen. Als erste Voraussetzung für eine solche Analyse wird die Möglichkeit der quantitativen Bindung von NH3 bzw. H2O im MIllimolbereich an einer Reihe von Reagenzien untersucht; die Bandenverschiebungen in den Spektren markierter Reaktionsprodukte werden angegebzn. Befriedigende Ergebnisse liefern Umsetzungen mit den Reagenzien Di-p-tolyl-carbodümid und 2,4-Dinitro-fluorbenzol. Am Beispiel der IR-Spektren von Di-p-tolyl-guanidin, den Reaktionsprodukt von N3 und Di-p-tolyl-carbodümid, wird gezeigt, daβ es möglich ist, die Bandenverschiebungen zur IR-spektralphotometrischen Isotopenanalyse auszumutzen. 相似文献
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Б. Р. Бои∂ареико В. А. В---асенко И. Г. Геер∂циме---u Τ. Α. гаƨуа Н. ш. Кu---а∂зе К. г Мче∂---u∂зе 《Isotopes in environmental and health studies》2013,49(3):97-100
Zur Gewinnung der Neonisotope in gröβeren Mengen ist die Gegenstromdestillation bei 28 K die geeingnetste Methode. Um das Verfahren ökonomisch durchzuführen, wurden Verdampfer und Kondensator mit dem Neonkältekreislauf gekoppelt. Die Schüttung der KOlonne besteht aus V2A-Wendeln (1,6 mm × 1,8 mm × 0.2 mm) und hat eine Höhe von 6000 mm. Bei zweimaliger Destillation wurden folgende Konzenbtrationen eereicht: für 22Ne 99,3% (maximal 99,5%), für 20Ne 99,97–99,99%. 24Ne wurde auf 1.2% (d. h. etwa das Vierfache der natürlichen Konzentration) angereichert. 相似文献
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V. A. Popov, P. P. Petrushev as well as H. Stahl and the first author obtained bilateral relations between best rational and piecewice-polynomial approximations in Lebesgue spaces L p [?1, 1], 1/p ? ? ∪ {0}. In the present paper we show that the restriction 1/p ? ? ∪ {0} cannot be dropped in these relations. 相似文献
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I.?S.?Ignat’ev V.?V.?Avrorin Т.?А.?KochinaEmail author Yu.?Е.?Ermolenko 《Russian Journal of General Chemistry》2018,88(3):470-473
Trichlorogermane triethylaminate [HGeCl3·NEt3] has been synthesized and its structure investigated using the methods of NMR and IR spectroscopy and quantum chemistry. Possible structures of complexes of triethylamine with trichlorogermane are considered. The presence of two minima on the potential energy surface is shown; the global minimum corresponds to the structure with proton transfer to the nitrogen atom, [Et3NH]+[GeCl3]–, while the local minimum lying by 25.8 kcal/mol above is characterized by the presence of very weak van-der-Waals interaction N···Ge. The comparison of the experimental and calculated chemical shifts of the proton is indicative of the formation of complex with proton transfer to the nitrogen atom in the liquid phase. 相似文献
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Е. P. Levanova V. S. Nikonova V. А. Grabel’nykh N. V. Russavskaya A. I. Albanov I. B. Rozentsveig N. А. Korchevin 《Russian Journal of General Chemistry》2018,88(3):383-388
Vinylidene chloride and 1,2-dichloroethene react with sulfur in the system hydrazine hydrate–KОН with the formation of polyvinylenesulfide oligomer of molecular mass 1750–6120 Da containing also vinylenehydrazine and vinylenechloride links in the Z-configuration, and 1,4-dithiine in the yield up to 46%. In aqueous-hydrazine layer polysulfide anions S n 2– (n = 1–4), mainly S22– were found. The mechanism of formation of oligomers and 1,4-dithiine is suggested, which includes in the first stage dehydrochlorination of dichloroethenes and generation of chloroacetylene. 相似文献
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Б. И. Голубов 《Analysis Mathematica》2008,34(1):9-28
For 2π-periodic functions f ∈ L p ( $ \mathbb{T} $ ), 1 ≤ p < ∞, σ ∈ V ( $ \mathbb{T} $ ) and g ∈ L( $ \mathbb{T} $ ), we consider the convolutions $$ (f*d\sigma )_T (x) = \int_0^{2\pi } {f(x - t)d\sigma (t), } (f*g)_T (x) = \int_0^{2\pi } {f(x - t)g(t)dt.} $$ For fixed functions σ ∈ V ( $ \mathbb{T} $ ) and g ∈ L( $ \mathbb{T} $ ), necessary and sufficient conditions are obtained for the density of the ranges of these operators in L p . Similar result is proved for the dyadic convolution $$ (f*g)_2 (x) = \int_0^1 {f(x \oplus t)g(t)dt,} $$ where ⊕ is the operation of dyadic addition on [0, 1). Moreover, it is proved that in the spaces L p ( $ \mathbb{T} $ ), 1 ≤ p ∞, and C( $ \mathbb{T} $ ) there exist no bases of shifts of a function. Similar results are obtained for the spaces L p [0, 1]*, 1 ≤ p < ∞, and C[0, 1]* relative to dyadic shifts, where [0, 1]* is the modified segment [0, 1]. It is also proved that in the space L(?+) there exists no basis of dyadic shifts of a function. 相似文献