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31.
A procedure has been developed for the selective preparation of 2-methylisoborneol by the action of methyllithium on camphane. It has been shown that the interaction of 2-methylisoborneol with aceto- and benzonitriles in the presence of sulfuric acid gives, as the result of a rearrangement of the carbon skeleton, high yields of the corresponding 1,4,7,7-tetramethylbicyclo[2.2.1]hept-exo-2-ylacylamines, which possess an anticataleptic action.Institute of Physical Organic Chemistry, Belarus Academy of Sciences, Minsk. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 719–723, November–December, 1994. 相似文献
32.
Pyatigorsk Pharmaceutical Institute. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 412–413, May–June, 1990. 相似文献
33.
Alexander V. Gusakov Arkady P. Sinitsyn Alejandro G. Berlin Nonna N. Popova Alexander V. Markov Oleg N. Okunev Dmitry F. Tikhomirov Mark Emalfarb 《Applied biochemistry and biotechnology》1998,75(2-3):279-293
A model microassay system was developed to measure indigo backstaining on cotton fabrics in the presence of enzymes on a small
laboratory scale. Backstaining indexes for 11 cellulase samples were measured, and the enzymes were ranked from lower to higher
backstaining. Two multienzyme cellulase preparations were separated into fractions using chromatofocusing on a Mono P column.
Adsorption ability and backstaining properties of purified enzyme fractions were studied. Evidence was obtained that protein
adsorption on cotton fabrics is a crucial parameter causing backstaining (both for crude cellulase samples and purified enzyme
components). 相似文献
34.
Z. Popova C. Dimitrov K. Aristirova R. P. Dimitrova L. Dukova G. Wendt 《Reaction Kinetics and Catalysis Letters》1988,36(1):85-90
Two series of nickel mordenite catalysts have been prepared on the basis of Na-mordenite and H-mordenite. Their catalytic activity in cyclohexane conversion has been studied. It has been found that the properties of the catalysts are strongly dependent on the acidity of mordenite.
NaM HM. .相似文献
35.
G. Ya. Popova T. V. Andrushkevich G. A. Metalkova 《Reaction Kinetics and Catalysis Letters》1979,12(4):469-473
Acrolein is oxidized to acrylic acid over a V–Mo catalyst by lattice oxygen, while the formation of CO2 also involves gas phase oxygen. The steady state of catalyst reduction is about 5% monolayer and is characterized by an oxygen binding energy of 61 kcal/mol.
V–Mo- , CO2 . 5% 61 /.相似文献
36.
G. N. Pirogova I. M. Kosareva N. N. Popova I. I. Byvsheva A. K. Pikaev 《High Energy Chemistry》2002,36(4):209-212
Radiolytic gas formation was measured in aqueous alkali–nitrate and alkali–nitrate–aluminate solutions simulating liquid intermediate-level wastes. The radiation-chemical yields of the gas mixture and its individual components depending on solution composition and irradiation temperature (up to 60°C) were determined. It was noted that oxygen was formed in comparatively high yields (up to 0.4 and 0.6 molecule/100 eV in alkali–nitrate–aluminate solutions at 30 and 60°C, respectively). This fact was explained by the decomposition of hydrogen peroxide, which is formed as a primary product of water radiolysis and in the combination of O– radical ions, and by the catalytic effect of aluminate ions. 相似文献
37.
1. | The authors have studied the formation of electron and hole paramagnetic centers in gamma-irradiated magnesium hydroxide and oxide with various degrees of dehydration. |
2. | Rise in the temperature of preliminary heat treatment of the magnesium oxide causes an increase in the radiation-chemical yield of FS + centers and a decrease in that of V su – centers. |
3. | The thermal stability of paramagnetic centers in magnesium oxide increases as the hydroxyl group content decreases. |
38.
Conclusions The reaction of diaminodibenzo-18-crown-6 with monochloroacetic anhydride in dioxane at room temperature gives 4,5-bis(chloroacetylamino)dibenzo-18-crown-6. The same reaction carried out in ethanol at reflux gives 4,5-bis(glycine hydrochloride)dibenzo-18-crown-6, which is converted in the presence of water to 8,9;17,18-bis(indoxyl)-18-crown-6.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 5, pp. 1160–1162, May, 1989. 相似文献
39.
The influence of the composition of lignocarbohydrate vegetable raw materials, process duration (15-120 min), amount of hydrogen peroxide (0.1-0.9 g per gram of raw materials), and amount of ammonia (0.25-1.5 g per gram of raw materials) on the yield of the target product and on the nitrogen content and the content of functional groups in it in mechanochemical treatment of vegetable wastes with hydrogen peroxide in aqueous ammonia (oxidative ammonolysis) was studied. Sorption and agrochemical testing of the resulting samples as nitrogen-containing ion exchangers and fertilizers was performed. 相似文献
40.
Mavrodinova V Popova M Valchev V Nickolov R Minchev Ch 《Journal of colloid and interface science》2005,286(1):268-273
Zeolite-based composite materials prepared by the embedding of the beta zeolite nanophase from aqueous colloidal solution into matrices of preformed Si(Al)MCM-41 mesoporous molecular sieves have been characterized by different methods (XRD, SEM, FTIR, N2 adsorption, and TPD of NH3). Their potential as catalysts for toluene disproportionation has been compared to mechanical mixtures of freeze-dried nanobeta crystallites with Si(Al)MCM-41 mesoporous materials. It is found that the zeolite catalyst efficiency is not substantially changed by the presence of mesopores belonging to the matrix. It is suggested that formation of intergrown aggregates from the colloidal nanobeta particles provides own highly developed textural mesoporosity that makes the contribution of the diffusional alleviation of the support negligible. 相似文献