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991.
E. N. Fedoseeva A. V. Budruev L. A. Smirnova Yu. D. Semchikov V. B. Fedoseev 《Polymer Science Series A》2007,49(8):868-875
It has been shown that the interaction of chitosan and oligochitosan with unsaturated acrylic esters via the nucleophilic addition mechanism and their condensation with heptadecyl isocyanate yield hydrophobic alkyl-containing derivatives of the above polymers. The method of modification of oligochitosan in reactions via end functional groups is developed. 相似文献
992.
V. A. Tartakovskii A. S. Ermakov Yu. A. Strelenko D. B. Vinogradov E. Yu. Petrov 《Russian Journal of Organic Chemistry》2005,41(1):120-123
A practical procedure has been proposed for the synthesis of functionally substituted 4,5-dihydro-1,2,3-oxadiazole 2-oxides on the basis ofsulfamic acid derivatives.__________Translated from Zhurnal Organicheskoi Khimii, Vol. 41, No. 1, 2005, pp. 121–123.Original Russian Text Copyright © 2005 by Tartakovskii, Ermakov, Strelenko, Vinogradov, Petrov. 相似文献
993.
本文报道了配体 2 ,2′-对苯二甲硫基二乙酸和过渡金属铜 ( )、钴 ( )、镍 ( )配合物的合成。经元素分析、X射线衍射分析、红外光谱、差热 -热重分析等推算了它们的组成并指认了谱带的归属。对铜 ( )配合物进行了电子顺磁共振谱研究。 相似文献
994.
Conclusions The partial hydrolysis of the pectin ofPanax ginseng C. A. Mey gives a polygalacturonide which has a linear carbohydrate chain consisting of residues of D-galacturonic acid in the pyranose form linked by -(1 4)-bonds.Khimiya Prirodnykh Soedinenii, Vol. 5, No. 4, pp. 201–203, 1969 相似文献
995.
R. A. Paegle M. G. Plata M. Yu. Lidak Yu. P. Shvachkin 《Chemistry of Heterocyclic Compounds》1971,4(5):659-660
The reaction of elementary bromine and iodine with -(3-uracyl)-propionic acid has given the corresponding -(5-bromo-3-uracyl) and -(5-iodo-3-uracyl)propionic acids. The methyl esters and amides of the acids have also been synthesized for the first time. 相似文献
996.
I. O. Konstantinov B. V. Zatolokin N. N. Krasnov Yu. G. Sevastyanov L. S. Volkova 《Journal of Radioanalytical and Nuclear Chemistry》1976,31(2):487-493
Procedures for determining traces of calcium, titanium, vanadium, chromium, iron, copper, niobium, molybdenum and tungsten
in tantalum are described utilizing 11 MeV proton activation. The instrumental method of analysis with the use of a Ge(Li)
detector and the radiochemical separation of the corresponding fractions are described. The formula for the calculation of
the concentration of traces with the use of thick target yields is given. Experimental data on the thick target yields of
radioisotopes44Sc,52Mn,56Co,65Zn,93mMo,96Tc are presented. Based on the experimental data, the detection limits are estimated at 1–10 ppb for the above mentioned metal
traces in tantalum. The successful solution of the task of the simultaneous determination of nine elements in tantalum confirms
the wide applicability of proton activation analysis. 相似文献
997.
A. N. Kost L. A. Sviridova G. A. Golubeva Yu. N. Portnov 《Chemistry of Heterocyclic Compounds》1970,6(3):344-348
The opening of the pyrazolidine ring at the nitrogen-nitrogen bond in 1-arylpyrazolidine under the influence of acidic agents which leads to the formation of N-(3-aminoalkyl)indoles is described. The method enables one to obtain indoles with branched aminoalkyl radicals.For part XIII see [1]. 相似文献
998.
A. Yu. Tyurin A. M. Churakov Yu. A. Strelenko M. O. Ratnikov V. A. Tartakovsky 《Russian Chemical Bulletin》2006,55(9):1648-1653
Thermolysis of o-diazidobenzotetrazine 1,3-dioxides was accompanied by cleavage of the C-C bond of the benzene ring to give nonannulated 1,2,3,4-tetrazine
1,3-dioxides. The structures of these first representatives of nonfused 1,2,3,4-tetrazines were confirmed by 13C and 14N NMR spectroscopy.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1589–1594, September, 2006. 相似文献
999.
F W Wang 《Macromolecules》1976,9(1):97-101
An equation for the translational diffusion coefficient of block copolymers in dilute solution has been obtained by modifying Zimm's equation for homopolymers to take into account the existence of dissimilar segments in block copolymers. Illustrative calculations for homopolymers and block copolymers have been made and the results for homopolymers have been compared with experiments and with the calculations of Yamakawa and Fujii. A procedure has been proposed to determine the molecular weight of a block copolymer from measurements of its limiting viscosity number and its sedimentation coefficient or translational diffusion coefficient. 相似文献
1000.
The concentration polarization phenomena in ion exchange membrane electrodialysis have been studied with single exchange membrane cell. The limiting current densities of Asahi ion-permselective membranes CK-1 and CK-2, Selemion ion-exchange membranes CMV, AMV, DMV and ASV have been measured with Ag-AgCl reversible electrode in various electrolyte solutions under 25°C and constant flow rate. In sodium chloride solution, the cation exchange membrane is easier to occur concentration polarization than the anion exchange membrane. The limiting current density increases as the concentration of solution increases for the same kind of ion exchange membrane. The experimental limiting current densities of Selemion CMV and AMV in NaCl, KCl, MgCl2, CaCl2, BaCl2, Na2SO4, NaOH and HCl aqueous solutions are measured. The results show that the limiting current density increases as the ion mobility and diffusivity increase, and is affected by the transference number of ion. For the mixture of electrolyte solution, there are linear relationship between limiting current density and equivalent fraction of electrolytes. 相似文献