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221.
Riassunto In questo lavoro sono studiati gli isomorfismi tra reticoli di sottogruppi normali di gruppi nilpotenti senza torsione. Si
prova che ogni gruppo iperciclico con la struttura normale di gruppo nilpotente senza torsione è un gruppo nilpotente sanza
torsione.
Summary Lattice isomorphisms between the normal structures of torsion-free nilpotent groups are studied in this paper. We prove that every hypercyclic group with the normal structure of a torsion-free nilpotent group is a torsion-free nilpotent group.相似文献
222.
Silvana Modena Pierangelo Calini Guglielmo Gregorio Giovanni Moggi 《Journal of fluorine chemistry》1988,40(2-3):349-357
Liquid phase fluorination of diethyleneglycol dimethyl ether tetraethyleneglycol dimethyl ether, 2[1,2-dichloro-1,2-difluoroethyl] tetrahydrofuran and 2[1,2-dichloro-1,2-difluoroethyl] dioxane 1,4 produce the corresponding perfluoroethers in 56, 43, 67 and 74 % yields respectively.
The by-products are partially fluorinated compounds and no fragmentation is observed.
The simplicity of the reactions and method of preparation make this approach to fluorinated fluids and oils industrially attractive. 相似文献
223.
Silvia Bradamante Silvana Colombo Giorgio A. Pagani Stefano Roelens 《Helvetica chimica acta》1981,64(2):568-571
Phenylglycine esters react with pyruvic acid to give α-methylsuccinic amides 9 instead of the expected Schiff bases 8 , analogously to p-anisidine but unlike aniline. 相似文献
224.
Silvia Bradamante Silvana Colombo Giorgio A. Pagani Stefano Roelens 《Helvetica chimica acta》1981,64(8):2524-2527
N-Substituted 9-fluorenimines 1 are easily prepared from primary amines or aminoesters and 9-fluorenimine: their conjugate carbanions 2 are formed by the action of alkoxides and are reprotonated to 1 or to the tautomeric 9-alkylidenamino-fluorenes 3 depending upon substituents. 相似文献
225.
Caputo R De Nisco M Festa P Guaragna A Palumbo G Pedatella S 《The Journal of organic chemistry》2004,69(21):7033-7037
4-Deoxy-l-hexoses were synthesized starting from our previously reported reagent 1 and (R)-benzyl glycidyl ether, which led in few steps to a substituted dihydropyran 6. The stereocontrolled hydroxylation of the latter afforded the corresponding 4-deoxy-l-hexoses 7a, 9, and 11. The same procedure, starting from (S)-benzyl glycidyl ether, enabled the preparation of their d-series enantiomers. 相似文献
226.
The author recently proved that 1-cotilting modules are pure-injective;however, the problem of determining whether n-cotilting modulesare pure-injective remained open. In this paper, necessary andsufficient conditions are given for the pure-injectivity ofn-cotilting modules. 2000 Mathematics Subject Classification16D90 (primary), 16D30 (secondary). 相似文献
227.
Palladium-catalyzed C–H alkenylation of quinoxaline N-oxide enabled by a mono-N-protected amino acid
Márcia Silvana Freire Franco Murilo Helder de Paula Paulina Cecylia Glowacka Fernando Fumagalli Giuliano Cesar Clososki Flavio da Silva Emery 《Tetrahedron letters》2018,59(26):2562-2566
The efficient alkenylation of quinoxaline N-oxide was achieved via Pd-catalyzed C–H activation, using the assistance of a mono-N-protected amino acid. Further deoxygenation of the 2-styrylquinoxaline-N-oxides yielded the corresponding styrylquinoxaline derivatives. 相似文献
228.
Liposomes can be effectively deposited on the inner surface of a capillary wall by flushing the electrophoretic system with a liposome suspension followed by air-drying of the capillary and removal of the excess of loosely bound liposomes by a 0.1 M NaOH wash. It was demonstrated that capillaries prepared in this way could be used for studies of analyte (drug)–liposome binding. The results were expressed as free binding energy changes [Δ(ΔG0)] relatively to an arbitrarily selected standard (acetylsalicylic acid). The results were compared to [Δ(ΔG0)] changes obtained from binding studies effected by capillary electrophoresis using a stable liposome plug in a capillary with minimized endoosmotic flow. Good agreement of data reported in the literature (without correction for the residual endoosmotic flow), our previous data obtained in a similar way (however, after the correction for the residual endoosmotic flow) and data obtained by the immobilized liposome affinity electrochromatography reported in this communication was achieved. 相似文献
229.
230.
Silvana T. Silveira Melissa S. Oliveira Jorge A. V. Costa Susana J. Kalil 《Applied biochemistry and biotechnology》2006,128(2):131-139
Glucoamylase production by Aspergillus niger in solid-state fermentation was optimized using factorial design and response surface techniques. The variables evaluated
were pH and bed thickness in tray, having as response enzyme production and productivity. The bed thickness in tray was the
most significant variable for both responses. The highest values for glucoamylase production occurred using pH 4.5 and bed
thickness in the inferior limits at 2.0–4.2 cm. For productivity, the optimal conditions were at pH 4.5 as well and bed thickness
from 4.4 to 7.5 cm. The optimal conditions for glucoamylase production while obtaining high activity without loss of productivity
were pH 4.5 and bed thickness in tray from 4.0 to 4.5 cm, which resulted in an enzyme production of 695 U/g and productivity
of 5791 U/h. 相似文献