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1.
M. A. Proskurnin N. V. Orlova A. V. Pikhtar' N. V. Osipova 《Journal of Analytical Chemistry》2004,59(5):433-437
Conditions are determined for the determination of salicylhydroxamic and acetylhydroxamic acids by thermal-lens spectrometry using iron(III) in an aqueous medium. The detection limits are 6 × 10–8 and 3 × 10–8 M, respectively. The sensitivity can be enhanced 3–6 times with the use of aqueous–organic media. 相似文献
2.
By the example of the problem of the motion of a semi-infinite string lying on an elastic base, a method for describing wave localization near inclusions is proposed for the case of a cubic nonlinearity of the base. The method applies the perturbation technique to the amplitude of a localized mode. The nature of the divergences is revealed, and the secular terms are found to belong to one of two types: inphase or antiphase with the localized wave. It is shown that a combination of the renormalization method and multiscale method provides a convergence of the solutions, which are sought for in the form of power series in the amplitude of the localized mode. It is found that the localization process is determined by the type of the discrete spectrum, type of the nonlinearity, and type of dispersion. The nonlinearity of the elastic base produces two characteristic effects. First, the frequency of the localized wave becomes dependent on the wave amplitude. Second, the system can generate traveling waves at multiple frequencies, which withdraw energy from the localized wave and cause it to decay. The decay behavior is determined by the minimum frequency of these traveling waves (because it must be higher than the cutoff frequency). The lifetime of the localized wave as a function of the mass of a dynamic inclusion exhibits a number of maxima. In particular, the first maximum corresponds to the minimum amplitude of the traveling wave at the triple frequency. 相似文献
3.
Perfluorocarboxylic thioesters RFC(O)SR (RF=CF3(CF2)j, R=CH3(CH2)i, i andj=0–5) were studied for the first time by GLC on packed columns using SE-30, SKTFT-50X, and XE-60 as the stationary phase.
The values of thermodynamics functions of sorption were calculated. The correlations between these functions and the molecular
structures as well as the conditions of analysis were established. The insertion of the S atom into the molecules of derivatives
of perfluorocarboxylic acids causes a decrease in the contribution of the orientation interaction and an increase in the dispersion
interaction of thioesters with the stationary phases compared to esters and amides of perfluorocarboxylic acids studied previously.
For Part 1, see Ref. 1.
Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1165–1168, June, 1997. 相似文献
4.
N. K. Zaitsev E. A. Osipova D. M. Fedulov A. G. Dedov 《Journal of Analytical Chemistry》2004,59(5):474-480
The effects of some factors (the nature and structure of organic compound R, the nature of the electrode material, the composition and concentration of the supporting electrolyte, the potential and time of electrolysis) on the formation and dissolution of electrochemical concentrates of the composition I2BrR were studied. The results obtained were used for determining iodide by cathodic stripping voltammetry in the concentration range of 6 to 500 g/L. The detection limit for iodide was found to be 0.2 g/L at an electrolysis time of 3 min. 相似文献
5.
Gas-liquid chromatography of thioesters of perfluorocarboxylic acids 1. Characteristics of retention
Retention of thioesters of perfluoropentanoic acid C4F9C(O)SR was studied by GLC on packed and capillary columns using stationary phases SE-30, SKTFT-50X, XE-60, and Carbowax 20M.
The retention indices of these compounds were calculated, and their relationship with the structure of the compounds and the
conditions of the analysis were established.
Translated fromIzvestiya Akademii, Nauk. Seriya Khimicheskaya, No. 5, pp. 984–986, May, 1997. 相似文献
6.
The influence of ammonia on propane oxidation over a Ga–Sb oxide catalyst has been studied. Acrylonitrile is formed upon the interaction of acrolein with partially dehydrogenated ammonia. Ammonia increases the rates of overall and selective oxidation of propane. This is assumed to be due to the formation of electron-donor sites promoting proton separation from the propane molecule.
. , . . , , .相似文献
7.
O. Yu. Ovsitser A. A. Davydov Z. G. Osipova V. D. Sokolovskii 《Reaction Kinetics and Catalysis Letters》1989,38(1):125-130
Rate constants for the aminolysis of o-(2,4-dinitrophenyl) cyclopentanone oxime with several primary alkylamines, C2H5NH2–C6H13NH2 and one secondary arylamine, purrolidine, in 11 water-acetonitrile are reported. With primary amines, base catalysis is absent, while with pyrrolidine saturation catalysis has been observed. Reduction in size of nonconjugated oxime moiety (leaving group), drastically decreases the rates. Thermodynamic parameters for these reactions have also been calculated.
O-(2,4-) (C2H5NH2–C6H13NH2) , , : =11. , . ( ) . .相似文献
8.
T. I. Osipova A. V. Belyankin A. R. Khomutov Yu. N. Zhukov E. N. Khurs R. M. Khomutov 《Russian Chemical Bulletin》1996,45(11):2588-2591
The reaction of ketoximes with hypophosphorous acid resulted in previously unknown -substituted--aminophosphinic acids, which were oxidized into the corresponding -substituted--aminophosphonic acids.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 11, pp. 2729–2732, November, 1996. 相似文献
9.
Summary Thallium trichloride exchanges two of its halogen atoms only for a radical that possesses a trans-configuratlon in cis-trans compounds, or for a radical that experiences electrophilic attack by the hydrogen ion in the decomposition of RHgR' by hydrochloric acid. 相似文献
10.
G. V. Itina A. A. Davydov M. A. Osipova L. N. Kurina 《Reaction Kinetics and Catalysis Letters》1991,45(2):243-249
The dependence between catalytic and surface acid-base properties of Zn–Cr–K catalysts has been established. Modification by potassium and an increase in potassium concentration promotes Zn–Cr–K reduction and raises the yield of higher alcohols. The spinel structure of catalysts is preserved.
Zn–Cr–K . Zn–Cr–K , .相似文献