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排序方式: 共有62条查询结果,搜索用时 46 毫秒
1.
R. D. Sinisterra R. Najjar O. L. Alves P. S. Santos C. A. Alves De Carvalho A. L. Conde Da Silva 《Journal of inclusion phenomena and macrocyclic chemistry》1995,22(2):91-98
The preparation and characterization of the 1:1 inclusion compound of rhodium(II) -methyl cinnamate in -cyclodextrin is reported. Evidence of inclusion was obtained from X-ray powder diffraction results, Raman, IR and UV-Vis spectroscopic studies and thermal analysis. Given the potential antitumor activity of the rhodium(II) carboxylate and its virtual insolubility in water, its inclusion in -cyclodextrin opens the possibility for its transference to the aqueous phase. 相似文献
2.
An AAC2 type mechanism is proposed for the esterification of several substituted benzoic acids on AlPO4 in the gas phase. The rate-controlling step is the surface reaction between an adsorbed molecule of acid and an unadsorbed molecule of ethanol. The KA and
constants, and the apparent Ea are determined.
2 AlPO4 . , , . - , .相似文献
3.
M. S. Climent J. M. Marinas J. V. Sinisterra 《Reaction Kinetics and Catalysis Letters》1989,38(1):13-19
Several new supported K2Cr2O7 reagents are used in the oxidation of secondary alcohols. The influence of the number of active sites and the nature of solid support on the yield is discussed. The influence of the structure of alcohol on the yield of ketone is analyzed.
K2Cr2O7 . . .相似文献
4.
J. V. Sinisterra F. Garcia Blanco M. Iglesias J. M. Marinas 《Reaction Kinetics and Catalysis Letters》1984,25(3-4):277-282
A general and repetitive method to determine the base strength and number of basic sites of catalysts with low surface area is reported. The nature of the titrating agent is discussed. The nature of the active sites of a Ba(OH)2 catalyst with low surface area is discussed.
. . Ba(OH)2, .相似文献
5.
A. García Raso J. V. Sinisterra J. M. Marinas 《Reaction Kinetics and Catalysis Letters》1982,18(1-2):33-37
The application of new Ba(OH)2 catalysts for the preparation of diacetone alcohol is described. No loss of activity is observed when they are stored in a dessiccator over NaOH. The same yield as that described in the literature is obtained, but in a much shorter reaction time (9.5 h against 72–120 h)
Ba(OH)2 . NaOH . , , (9,5 72–120 ).相似文献
6.
A tentative assignment of the vibrational modes of sulphadiazine is made, based on the infrared and Raman data. In addition, dirhodium tetracarboxylates and their adducts with sulphadiazine are investigated by Raman spectroscopy, with emphasis in the identify the metal-metal and metalligand stretching modes. 相似文献
7.
ABSTRACT Copolymers of 1,5-dioxepan-2-one (DXO) and e-caprolactone (?-CL), δ-valerolactone (δ-VL) or L-lactide (LLA) have been synthesized and characterized. High molecular weight copolymers were obtained using stannous-2-ethyl hexanoate as catalyst in bulk. Reactivity ratios for the copolymerization of DXO and δ-VL were determined at 110°C as rVL=0.5 and rDXO=2.3. At high conversion, depolymerization of δ-VL occurred, resulting in lower molecular weight and variations in the copolymer composition. Physical properties, such as crystallinity and melting temperature of the DXO-copolymers proved to be strongly dependent on the choice of comonomer and on the molar composition of the copolymers. DXO appears to be incorporated into the poly-?-caprolactone (PCL) crystals and to some extent into the poly-δ-valerolactone (PVL) crystals, resulting in a more gradual decrease in crystallinity with increasing amount of DXO. 相似文献
8.
A Mukherjee M Dasgupta DJ Hinde CR Morton AC Berriman RD Butt JO Newton H Timmers 《Pramana》2001,57(1):195-198
Fusion cross-sections for the 7Li + 12C reaction have been measured at energies above the Coulomb barrier by the direct detection of evaporation residues. The heavy
evaporation residues with energies below 3 MeV could not be separated out from the α-particles in the spectrum and hence their
contribution was estimated using statistical model calculations. The present work indicates that suppression of fusion cross-sections
due to the breakup of 7Li may not be significant for 7Li + 12C reaction at energies around the barrier. 相似文献
9.
RD Harris WS Baker Van Stipdonk MJ RM Crooks EA Schweikert 《Rapid communications in mass spectrometry : RCM》1999,13(14):1374-1380
A suite of keV polyatomic or 'cluster' projectiles was used to bombard unoxidized and oxidized self-assembled monolayer surfaces. Negative secondary ion yields, collected at the limit of single ion impacts, were measured and compared for both molecular and fragment ions. In contrast to targets that are orders of magnitude thicker than the penetration range of the primary ions, secondary ion yields from polyatomic projectile impacts on self-assembled monolayers show little to no enhancement when compared with monatomic projectiles at the same velocity. This unusual trend is most likely due to the structural arrangement and bonding characteristics of the monolayer molecules with the Au(111). Copyright 1999 John Wiley & Sons, Ltd. 相似文献
10.
J. V. Sinisterra M. E. Borredon Z. Mouloungui M. Delmas A. Gaset 《Reaction Kinetics and Catalysis Letters》1985,29(1):41-47
The nature of adsorbed sulfonium and phosphonate ylids on a new barium hydroxide catalyst (C-200) is analyzed by IR. The catalytic activity of C-200 in solid-liquid phase transfer conditions is explained by these IR studies.
(C-200) . C-200 - .相似文献