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排序方式: 共有226条查询结果,搜索用时 15 毫秒
71.
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73.
A Convenient Regiospecific Syntheses of (E)-1-Alkanesulfonyl- and (E)-1-Arylsulfonyl-2-Phenylethenes
(E)-1-Alkanesulfonyl- and (E)-1-arylsulfonyl-2-phenylethenes (styryl sulfones) were obtained from good to excellent yields by the base-catalyzed elimination of the corresponding β-chlorosulfones. The latter were obtained, respectively, by additions of the alkanesulfonyl- and the arylsulfonyl chlorides to styrene under the catalytic action of copper chlorides. 相似文献
74.
Lilian F. Berti Aurelio R. L. Oliveira Carla T. L. S. Ghidini 《Mathematical Methods of Operations Research》2017,85(1):61-75
In this paper, we present a proposal for a variation of the predictor–corrector interior point method with multiple centrality corrections. The new method uses the continued iteration to compute a new search direction for the predictor corrector method. The purpose of incorporating the continued iteration is to reduce the overall computational cost required to solve a linear programming problem. The computational results constitute evidence of the improvement obtained with the use of this technique combined with the interior point method. 相似文献
75.
V. Mussi A. Cricenti B. Jacquier T. Marolo R. M. Montereali P. Moretti 《辐射效应与固体损伤》2013,168(1-6):181-184
The measured room-temperature absorption spectra of LiF crystals implanted with 1.5 MeV He? ions at different ion doses are presented. The application of a theoretical model allowed us to give an estimation of the band intensities associated with various kinds of electronic defects and to study their dependence on the ion dose. The model also considers the contribution due to nanometric lithium colloids, whose formation starts in the dose range at which the production of colour centres saturates. 相似文献
76.
Lilian Buriol Taiana S. München Clarissa P. Frizzo Mara R.B. Marzari Nilo Zanatta Helio G. Bonacorso Marcos A.P. Martins 《Ultrasonics sonochemistry》2013,20(5):1139-1143
Pyrazolo[1,5-a]pyrimidines were synthesized via the ultrasonic sonochemical method using the cyclocondensation reaction of 4-alkoxy-1,1,1-trifluoro-3-alken-2-ones [CF3C(O)CH = C(R)(OMe) – where R = Me, Bu, i-Bu, Ph, 4-Me–C6H4, 4-F–C6H4, 4-Cl–C6H4, 4-Br–C6H4, naphth-2-yl and biphen-4-yl] – with 3-amino-5-methyl-1H-pyrazole in the presence of EtOH for 5 min. This methodology has several advantages, for example, it is a simple procedure, it has an easy work-up, mild conditions, short reaction times (5 min) and produces satisfactory yields (61–98%). 相似文献
77.
Fanzio P Mussi V Manneschi C Angeli E Firpo G Repetto L Valbusa U 《Lab on a chip》2011,11(17):2961-2966
We present the development and the electrical characterization of a polymeric nanochannel device. Standard microfabrication coupled to Focused Ion Beam (FIB) nanofabrication is used to fabricate a silicon master, which can be then replicated in a polymeric material by soft lithography. Such an elastomeric nanochannel device is used to study DNA translocation events during electrophoresis experiments. Our results demonstrate that an easy and low cost fabrication technique allows creation of a low noise device for single molecule analysis. 相似文献
78.
Li J Durry G Cousin J Joly L Parvitte B Zeninari V 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2012,85(1):74-78
By using a high resolution tunable diode laser absorption spectrometer combined with a cryogenically cooled optical multi-pass cell, we have measured the self-induced pressure shift coefficients for 8 transitions in the R branch of the (20(0)1)(III)←(00(0)0)(I) band of carbon dioxide around 2.05μm. This spectral region is of particular interest for the monitoring of atmospheric CO(2) with Differential Absorption Lidars (DiAL). The measurement of these shift coefficients was realized at five different temperatures ranging from 218 to 292K in order to determine their temperature dependence. The results are thoroughly compared to previous values reported in the literature for the (20(0)1)(III)←(00(0)0)(I) band of CO(2). The temperature dependence of the self-induced pressure shifts are reported experimentally for the first time for this specific CO(2) band. 相似文献
79.
Humberto Carrión Pablo Galindo Mary Lilian Lourenço 《Complex Analysis and Operator Theory》2013,7(1):107-114
We present an infinite-dimensional version of Cartan-Carathéodory-Kaup-Wu theorem about the analyticity of the inverse of a given analytic mapping. It is valid for a class of domains in separable Banach dual spaces that includes all bounded convex domains. 相似文献
80.
Marcelo Coelho Silva Jeancarlo Pereira dos Anjos Lilian Lefol Nani Guarieiro Bruna A. Souza Machado 《Molecules (Basel, Switzerland)》2021,26(16)
There are a significant number of analytical methodologies employing different techniques to determine phenolic compounds in beverages. However, these methods employ long sample preparation processes and great time consumption. The aim of this paper was the development of a simple method for evaluating the phenolic compounds’ presence in Brazilian craft beers without a previous extraction step. Catechin, caffeic acid, epicatechin, p-coumaric acid, hydrated rutin, trans-ferulic acid, quercetin, kaempferol, and formononetin were analyzed in fifteen different craft beers. The method showed good linearity (R2 ≥ 0.9966). The limit of detection ranged from 0.08 to 0.83 mg L−1, and limits of quantification were between 0.27 and 2.78 mg L−1. The method showed a satisfactory precision (RSD ≤ 16.2%). A good accuracy was obtained by the proposed method for all phenolic compounds in craft beer (68.6% ˂ accuracy ˂ 112%). Catechin showed higher concentrations (up to 124.8 mg L−1) in the samples, followed by epicatechin (up to 51.1 mg L−1) and caffeic acid (up to 8.13 mg L−1). Rutin and formononetin were observed in all analyzed samples (0.52 mg L−1 to 2.40 mg L−1), and kaempferol was less present in the samples. The presence of plant origin products was determinant for the occurrence of the highest concentrations of phenolic compounds in Brazilian craft beers. 相似文献