The mineral and chemical compositions, as well as some structure-sorption characteristics were determined for clay minerals selected for examination. The integrated coefficients of contamination of bottom sediments with each of the toxicant metals (Fe, Ni, Co, Cu, Zn, Pb, Mn) were calculated. The minerals examined presumably can be used in medicine as efficient application materials, cosmetic agents, and sorbents (enterosorbents). 相似文献
The features of anthracite oxidation as influenced by temperature and time were determined. Physicochemical and sorption characteristics of the resulting cation exchanger were studied. 相似文献
Sorption of Cu(II), Pb(II), Cd(II), and Zn(II) from aqueous solutions on two-component organosilicas was studied as influenced by sorbent composition, contact time, ratio of solid and liquid phases, solution pH, nature and concentration of heavy metal ions, and content of modifying agent. The degrees of sorption of these metal ions from aqueous solutions using organosilicas modified with aluminum(III) added into the siloxane matrix or with copper(II) grafted to the sorbent surface layer were compared. 相似文献
The oxidation of -terpinene by molecular oxygen is shown to occur by a radical chain mechanism involving hydroperoxy radicals. The principal molecular reaction products are H2O2 and 1-methyl-4-isopropylbenzene. The rate constants for chain propagation and chain breaking measured at 35–70°C are (liter/mol·s) lgk3 = 7.10– (6700±400)/4.57T and lgk5 = 9.80– (2700±300)/4.57T respectively.Translated from Teoreticheskaya Éksperimental'naya Khimiya, Vol. 30, No. 3, pp. 143–146, May–June, 1994The authors thank the Ukraine National Committee for the Basic Research Fund for financing this work. 相似文献
Symmetrical mono-, tri-, and pentamethinecyanine dyes with a thiazolo[3,4-b][1,2,4]triazine ring were synthesized. The electron-density distributions in the dye molecules in the ground and first and second excited states were obtained by quantum-chemical calculations. It was established that the first two electron transitions are localized on the same atoms and that charge transfer to the triazine fragment of the molecule is realized in the case of excitation. The degree of participation of the heterocyclic ring in the first electron transition, which is responsible for the color of the dye, decreases with lengthening of the polymethine chain.See [1] for communication 13.Translated from Khimiya Geterotsiklicheskikh Soedinenii, Vol. 24, No. 3, pp. 418–423, March, 1988. 相似文献
Rate constants for the reactions between HOO radicals and [2-(R-N= CH)C6H4O]2Cu decreased according to the nature of the R substituent in the order (70°C): CH3 > n-C4H9 > iso-C3H7 > cyclo-C6H11 > tert-C4H9; this followed the same sequence as the Charton steric constants of the R substituents.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 29, No. 1, pp. 70–73, January–February, 1993.The authors would like to express their gratitude to the Ukrainian Basic Reaearch Fund for financing the current work. 相似文献
The colloidal chemical properties of triple block copolymers of polypropylene oxide and polyethylene oxide (pluronics of various structures) were studied in comparison. All of them are shown to be surfactants but differ in interfacial tension, surface activity, surface area occupied in the adsorption layer, and adsorption layer thickness. The kinetic regularities of polymerization of styrene and methyl methacrylate were studied. The particle diameters and their size distribution were determined. Distinctions in the kinetic regularities of polymerization are shown: the shape of the conversion—time curves (for the duration of the initial and stationary stages of polymerization) and the dependences of the diameter on the surfactant concentration and monomer to water volume ratio. In the presence of the water-insoluble pluronics, the mechanism of formation of polymer—monomer particles and interfacial layer on the surface differs from that when using water-soluble surfactants, which makes it possible to distinguish these processes into an independent type of heterophase polymerization.
Theoretical and Experimental Chemistry - The sorption of Cs+, Sr2+, and $$ {\mathrm{UO}}_2^{2+} $$ ions on bulk ammonium molibdophosphate (AMP) and also on compositions obtained by its deposition... 相似文献