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1.
Dipl.‐Chem. Nicolas Dietl Dr. Anna Troiani Dr. Maria Schlangen Dr. Ornella Ursini Dr. Giancarlo Angelini Prof. Dr. Yitzhak Apeloig Prof. Dr. Giulia de Petris Prof. Dr. Helmut Schwarz 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(21):6662-6669
The reactivity of the two diatomic congeneric systems [CO].+ and [SiO].+ towards methane has been investigated by means of mass spectrometry and quantum‐chemical calculations. While [CO].+ gives rise to three different reaction channels, [SiO].+ reacts only by hydrogen‐atom transfer (HAT) from methane under thermal conditions. A theoretical analysis of the respective HAT processes reveals two distinctly different mechanistic pathways for [CO].+ and [SiO].+, and a comparison to the higher metal oxides of Group 14 emphasizes the particular role of carbon as a second‐row p element. 相似文献
2.
Paolo Giusti Luigi Lazzeri Niccoletta Barbani Letizia Lelli Silvano De Petris Maria G. Cascone 《Macromolecular Symposia》1994,78(1):285-297
Blends of natural and synthetic polymers were studied for potential applications in the biomedical field. Collagen and hyaluronic acid were mixed in aqueous solution with poly(vinyl alcohol) and poly(acrylic acid). The properties of the blends were studied by differential scanning calorimetry and dynamic mechanical thermal analysis. Some methods were also investigated to enhance the miscibility of the polymers in these blends. 相似文献
3.
Bernardi F Cacace F de Petris G Pepi F Rossi I Troiani A 《Chemistry (Weinheim an der Bergstrasse, Germany)》2000,6(3):537-544
A comparative study of the gas-phase reactions of NO2+ with acetylene and ethylene was performed by using FT-ICR, MIKE, CAD, and NfR/ CA mass spectrometric techniques, in conjunction with ab initio calculations at the MP2/6-31+G* level of theory. Both reactions proceed according to the same mechanism, that is, 1,3-dipolar cycloaddition, but yield products of different stability. The C2H2NO2+ adduct from acetylene has an aromatic character and hence is highly stabilized with respect to the C2H4NO2+ adduct from ethylene. Both cycloadducts tend to isomerize into O-nitroso derivatives, that is, nitrosated ketene and nitrosated acetaldehyde, which represent the thermodynamically most stable products from the addition of NO2+ to acetylene and ethylene, respectively. As prototypal examples of the reactivity of free nitronium ions with most simple pi systems, the reactions investigated are useful starting points to model the mechanism of aromatic nitration. 相似文献
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P. De Bernardis E. Aquilini A. Boscaleri M. De Petris M. Gervasi L. Martinis S. Masi V. Natale P. Palumbo F. Scaramuzzi 《Il Nuovo Cimento C》1993,16(6):721-726
Summary We describe a balloon-borne telescope, optimized for observations of the Cosmic Microwave Background (CMB) anisotropies in
the mm wavelength region, at angular scales around 10. We stress the scientific motivations for these measurements and the problematics driving the experiment design. Using large
throughput bolometers cooled at 0.3K we have a sensitivity high enough to detect CMB anisotropies at level ΔT/T∼10−5 in few seconds of integration time.
Paper presented at the 6th Cosmic Physics National Conference, Palermo, 3–7 November 1992. 相似文献
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Sandra Fortini Lucia Ladelli Giovanni Petris Eugenio Regazzini 《Stochastic Processes and their Applications》2002,100(1-2):147-165
Let X be a chain with discrete state space I, and V be the matrix of entries Vi,n, where Vi,n denotes the position of the process immediately after the nth visit to i. We prove that the law of X is a mixture of laws of Markov chains if and only if the distribution of V is invariant under finite permutations within rows (i.e., the Vi,n's are partially exchangeable in the sense of de Finetti). We also prove that an analogous statement holds true for mixtures of laws of Markov chains with a general state space and atomic kernels. Going back to the discrete case, we analyze the relationships between partial exchangeability of V and Markov exchangeability in the sense of Diaconis and Freedman. The main statement is that the former is stronger than the latter, but the two are equivalent under the assumption of recurrence. Combination of this equivalence with the aforesaid representation theorem gives the Diaconis and Freedman basic result for mixtures of Markov chains. 相似文献
9.
Ring and open-chain S3O sulfur oxides are detected by neutralization-reionization experiments. 相似文献