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71.
Chemistry of Natural Compounds - The epigeal part ofArtemisia santolina Schrenk has yielded a new sesquiterpene lactone, artesin, C14H22O3, having the structure... 相似文献
72.
U. G. Magomedbekov Kh. M. Gasanova U. G. Gasangadzhieva K. A. Abdulkhamidov S. Sh. Mutsalova 《Moscow University Chemistry Bulletin》2007,62(4):230-236
A possible mechanism of 1,4-naphthalenediol oxidation in the oscillatory regime has been considered, and a mathematical model describing the kinetics has been developed. Based on a thermodynamic Lyapunov function, it has been shown that the source of chemical instabilities is in the existence of autocatalytic steps and dynamic feedbacks. Qualitative analysis and numerical solution of the set of differential equations that model the reaction kinetics have been performed. The character of the stationary state and the possibility of bifurcations have been determined. The mathematical model satisfactorily describes the processes occurring in the system. 相似文献
73.
74.
Alkynyl-substituted indene was first used as a ligand for the synthesis of transition metal complexes. ansa-Zirconocenes containing ethylene and dimethylsilylene bridges were synthesized starting from 2-(phenylethynyl)-1H-indene. The structure of the former compound was established by X-ray diffraction.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 68–73, January, 2007. 相似文献
75.
L. Sh. Afanasiadi L. D. Patsenker S. A. Verezubova A. P. Shkumat V. K. Polyakov 《Chemistry of Heterocyclic Compounds》1986,22(9):1028-1031
A number of new organic luminophores were synthesized via the Wittig reaction from 2-(4-bromomethylphenyl)-5-phenyloxazole or 2-(4-bromomethylphenyl)-5-phenyl-1,3,4-oxadiazole and various heterocyclic aldehydes containing a thiophene ring.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1267–1270, September, 1986. 相似文献
76.
Solid solutions based on K3PO4 in systems K3 – 4x
E"
x
PO4 (E" = Si, Ti, Ge, Zr, Sn, Hf, Ce) are synthesized. The crystal structure, thermal behavior, and electroconduction of the synthesized solutions is studied. The narrowest single-phase regions take place in the systems where E" = Si, Ge (x 0.025), and the widest, in the system with Zr (x 0.125, at 700°C). Introducing Ti or Sn additives (x 0.05) and minimum quantities of Zr, Hf, or Ce (x = 0.025) into potassium orthophosphate leads to stabilization of highly-conductive -modification of K3PO4 at room temperature. Maximum values of potassium-cation conduction in all the systems studied correspond to regions of single-phase solid solutions based on K3PO4. The maximum electroconductivity (0.005 S cm–1 at 300°C, 0.1 S cm–1 at 700°C) and the smallest activation energies (32–35 kJ mol–1) take place in the systems with Zr and Hf. 相似文献
77.
Sal'keeva L. K. Nurmagambetova M. T. Kurmanaliev O. Sh. 《Russian Journal of General Chemistry》2002,72(12):1955-1955
Russian Journal of General Chemistry - 相似文献
78.
The liquid-liquid extraction, ion and precipitate flotation of Co(II) from chloride media of 1·10–4M initial Co(II) concentration and =0.1 have been investigated using decanoic acid and the results are compared. Organic solvents used were chloroform in the case of liquid-liquid extraction and ethanol (used as a solvent for the collector and a frother) in the case of flotation. From the results it appears that liquid-liquid extraction takes place through the formation of the complex: (CoR2)2(HR)2 but flotation occurs through the formation of a surface active product which has the empirical formula CoR2. The effects of pH and of decanoic acid concentration on the three separation processes were also investigated and the results discussed. Good agreement was observed between the experimental precipitate flotation curves and the theoretical curve calculated from the data published for Co(II) hydrolysis. 相似文献
79.
A. A. Toropov V. O. Kudyshkin N. L. Voropaeva I. N. Ruban S. Sh. Rashidova 《Journal of Structural Chemistry》2004,45(6):945-950
For a series of monomers, QSPR test analysis is performed by optimizing the correlation weights of the local invariants of molecular graphs representing monomer structures in order to construct models of the reactivity parameters of monomers Q and e. This approach may be used as a tool in reactivity predictions for monomers for which no experimental data on Q and e are available.Original Russian Text Copyright © 2004 by A. A. Toropov, V. O. Kudyshkin, N. L. Voropaeva, I. N. Ruban, and S. Sh. Rashidova__________Translated from Zhurnal Strukturnoi Khimii, Vol. 45, No. 6, pp. 994–998, November–December, 2004. 相似文献
80.