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51.
52.
Conclusions Both the extent of C2H4 hydropolymerization, initiated by 0.01% CO, on Co zeolites at a temperature below 100°C, and the initiating effect increase symbatically with increase in the ratio of SiO2/Al2O3 in the zeolite in the investigated limits (from 2 to 10).Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 4, pp. 894–896, April, 1974. 相似文献
53.
54.
S. V. Baires D. É Vallen K. M. Enikeev A. S. Khramov V. E. Bel'skii A. V. Il'yasov B. E. Ivanov 《Russian Chemical Bulletin》1992,41(10):1801-1804
The interaction of synthetic analogs of active centers of iron-sulfur proteins with phosphates of different structures was studied. It was shown that the process involves ligand exchange and obeys the first-order reaction kinetic equation. The most rapid exchange occurred with the most acidic compound diphenyl phosphate.A. E. Arbuzov Institute of Organic and Physical Chemistry, Kazan' Scientific Center, Russian Academy of Sciences, 420083 Kazan'. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 10, pp. 2301–2305, October, 1992. 相似文献
55.
Iodine-poly(2-vinylpyridine-co-styrene-co-divinylbenzene) charge transfer complexes with antibacterial activity 总被引:1,自引:0,他引:1
Angela Cristina Jandrey Mônica Regina Marques Palermo de Aguiar José Luiz Mazzei 《European Polymer Journal》2007,43(11):4712-4718
In this work, we have developed three different copolymers based on 2-vinylpyridine, styrene and crosslinked with divinylbenzene (10-30 mol%). The copolymers were morphologically and chemically characterized by apparent density, swelling degree, elemental analysis, Fourier transform infrared spectrophotometry and optical microscopy. The formation of iodine complexes with these copolymers was carried out by two different procedures: with solvent, or not. The influence of the copolymers structure on the capacity of anchoring iodine has been investigated. The antibacterial properties of polymeric charge transfer complexes were determined towards 103-107 cells/mL dilutions from the auxotrophic AB1157 Escherichia coli strain. 相似文献
56.
Pocha R Johrendt D Ni B Abd-Elmeguid MM 《Journal of the American Chemical Society》2005,127(24):8732-8740
The crystal structures of the tetrahedral cluster compounds GaNb(4)S(8) and GaTa(4)Se(8) were determined by single-crystal X-ray diffraction. They crystallize in the cubic GaMo(4)S(8) structure type (F3m), which can be derived from the spinel type by shifting the metal atoms off the centers of the chalcogen octahedra along [111]. Electrical resistivity and magnetic susceptibility measurements show that the electronic conduction originates from hopping of localized unpaired electrons (S = (1)/(2)) among widely separated Nb(4) or Ta(4) clusters, and thus these materials represent a new class of Mott insulators. Under high pressure we find that GaNb(4)S(8) undergoes a transition from the Mott insulating to a superconducting state with T(C) up to 4 K at 23 GPa, similar to GaNb(4)Se(8) and GaTa(4)Se(8). High-pressure single-crystal X-ray studies of GaTa(4)Se(8) reveal that the superconducting transition is connected with a gradual decrease of the octahedral distortion with increasing pressure. DFT band structure calculations show that weakly coupled cluster orbitals are responsible for a high density of states at the Fermi level. The correct insulating magnetic ground state for GaNb(4)S(8) with mu(eff) = 1.73 mu(B) is for the first time achieved by the LDA+U method using U = 6 eV and rhombohedral symmetry. 相似文献
57.
A. A. Ladatko I. D. Sadekov L. N. Étmetchenko V. I. Minkin 《Chemistry of Heterocyclic Compounds》1989,25(5):577-580
10-Telluroniaanthracene perchlorates react with nucleophiles (X–=halide, hydroxide, methoxide) via intermediate free telluroxanthyl radicals. With 9-aryl-10-telluroniaanthracene perchlorates, high yields of 9-aryl-9-X-telluroxanthenes are obtained, but with 10-telluroniaanthracene the principal product is 9,9-bis(telluroxathenyl) as a result of rapid competitive dimerization.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 691–695, May, 1989. 相似文献
58.
Regina Y. Moriya Adilson R. Gonçalves Fabrícia P. Faria 《Applied biochemistry and biotechnology》2005,121(1-3):195-203
Organosolv (ethanol/water and acetosolv) pulps were treated with Humicola grisea var. thermoidea and compared with Cartazyme HS xylanase-treated pulp. The ethanol/water pulps treated with H. grisea had the same viscosity as unbleached pulps (8 cP). Ethanol/water pulps treated with Cartazyme had higher viscosity than H. grisea-treated pulps (12 cP). Acetosolv pulps treated with H. grisea and Cartazyme presented a reduction in viscosity; however, the pulps treated with H. grisea had a lower reduction in viscosity than Cartazyme-treated pulps. Ethanol/water pulps treated with H. grisea had a 23% reduction in kappa number in 4 and 8 h of treatment, compared with the unbleached pulps. Cartazyme-treated pulps
had a kappa number similar to that of the control pulps for 4 h of treatment. Extending the treatment time to 12 h resulted
in a reduction of 33%. The acetosolv pulp treated with H. grisea had a kappa number reduced to 23% in 4 h. Cartazyme treatment resulted in a reduction of 55 and 44% in kappa number for 4
and 8 h of treatment, respectively, when compared with control pulp. Extending the treatment time to 12 h decreased the kappa
number 72%. Fourier transform infrared spectra and principal component analysis showed differences among unbleached, H. grisea-treated, and Cartazyme-treated pulps. 相似文献
59.
R. G. Mirzoyan S. M. Saakyan P. B. Terent'ev K. A. Éliazyan V. V. Dovlatyan 《Chemistry of Heterocyclic Compounds》1982,18(9):983-985
Intense [M-Cl]+ and [M-CT2=CCNCl]+ ion peaks are characteristic for the mass spectra of 4-(-chloro--cyanoethylmercapto)-sym-triazines. The introduction of monoalkylamino groups into the 2 and 6 positions of the heteroring does not lead to the development of [M-HCl]+ ion peaks in the mass spectra or to a change in the characteristic fragmentation pathways.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1268–1270, September, 1982. 相似文献
60.
Karlheinz Ballschmiter Rainer Bacher Angela Mennel Regina Fischer Ulrich Riehle Max Swerev 《Journal of separation science》1992,15(4):260-270
High resolution gas chromatography, with mass selective detection, has been used for the analysis of PCB on methyl 50 % octyl polysiloxane (SB 50 Octyl), methyl octadecyl polysiloxane, and a smectic polysiloxane (SB Smectic); and for the analysis of polychlorodibenzodioxins and polychlorodibenzofurans with 1 to 8 chlorine substituents on 100 % cyanopropyl siloxane (SP 2331), smectic polysiloxane (SB Smectic), a new polar stationary phase (DB-Dioxin). The analysis has also been performed by column coupling. 相似文献