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81.
Maria Auxiliadora Fontes Prado Ricardo José Alves Alaíde Braga de Oliveira José Dias de Souza Filho 《合成通讯》2013,43(5):1015-1022
6-acetamido-6,8-dideox-1,2:3,4-di-O-isopropylidene- D -glycero-α-D-galacto-octopyranos-7-ulose (6), has been synthesised from D -galactose. The side chain elongation was carried out by cyano-amination of the protected dialdo sugar (2), followed by N-acetylation, and a subsequent Grignard reaction. 相似文献
82.
Luiz Renato Fontes Domingos H. U. Marchetti Immacolata Merola Errico Presutti Maria Eulalia Vares 《Journal of statistical physics》2014,157(3):407-421
We consider the Ising model on \(\mathbb Z\times \mathbb Z\) where on each horizontal line \(\{(x,i), x\in \mathbb Z\}\) , called “layer”, the interaction is given by a ferromagnetic Kac potential with coupling strength \(J_{ \gamma }(x,y)={ \gamma }J({ \gamma }(x-y))\) , where \(J(\cdot )\) is smooth and has compact support; we then add a nearest neighbor ferromagnetic vertical interaction of strength \({ \gamma }^{A}\) , where \(A\ge 2\) is fixed, and prove that for any \(\beta \) larger than the mean field critical value there is a phase transition for all \({ \gamma }\) small enough. 相似文献
83.
Ludivine Bouvier‐Fontes Rosangela Pirri Jos M. Asua Jose R. Leiza 《Journal of polymer science. Part A, Polymer chemistry》2005,43(20):4684-4694
The emulsion copolymerization of butyl acrylate (BA) with a trifunctional cross‐linker, diallyl maleate (DAM), was investigated. The effect of the monomer feeding time and the amount of cross‐linker on the microstructural properties (branching, cross‐linking, gel formation, and sol MWD) of the seeded semicontinuous emulsion copolymerization of BA with DAM was investigated. It was found that the gel content was not significantly affected by increasing feeding time, but the level of quaternary carbons (an indication of the branching density) increased. On the other hand, increasing the amount of DAM in the feed composition caused gel content, level of quaternary carbons, and the cross‐linking density to increase. Interestingly, the level of quaternary carbons and the cross‐linking density sharply increased during the cooking period. The molecular weight of the sol decreased as DAM increased in the feed. In addition, the effect of process type, batch versus semibatch, was also considered and important differences in the level of quaternary carbons, cross‐linking, and gel content were found. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 4684–4694, 2005 相似文献
84.
85.
de Carmargo V. F. Fontes E. H. Nandenha J. de Souza R. F. B. Neto A. O. 《Research on Chemical Intermediates》2020,46(2):1555-1570
Research on Chemical Intermediates - PtRh/C–ITO electrocatalysts were prepared in a single-step method using H2PtCl6·6H2O and RhCl3·xH2O as metal sources, sodium borohydride as the... 相似文献
86.
Characterization and comparative study of pyrolysis kinetics of the rice husk and the elephant grass
Renata M. Braga Dulce M. A. Melo Flavia M. Aquino Julio C. O. Freitas Marcus A. F. Melo Joana M. F. Barros Maria S. B. Fontes 《Journal of Thermal Analysis and Calorimetry》2014,115(2):1915-1920
A comparative evaluation of different biomasses allows the choice that presents the best potential as fuel for energy production. The knowledge of the thermal and kinetics parameters of the biomass in the process of thermal conversion is fundamental as their chemical and physical characterization. Various methodologies have been developed for the determination of kinetic parameters as apparent activation energy and reaction order from the thermogravimetric analysis. In this work, the apparent activation energy needed to break the bonds of hemicelluloses and cellulose of rice husk and elephant grass during the thermal conversion was evaluated according to the kinetics models of Flynn and Wall and Model Free Kinetics developed by Vyazovkin. The biomass elephant grass and rice husk were characterized for moisture, ash and volatile matter by ASTM E871, ASTM E1755, ASTM E872, respectively, and fixed carbon by difference. The percentage of carbon, hydrogen, nitrogen, and oxygen were determined by ultimate analysis. The elephant grass showed to be more suitable for production of bio-oil through pyrolysis due to the higher percentage of volatile, less ash content and less energy required to break the bonds of hemicellulose and cellulose than rice husk in the thermal conversion process. 相似文献
87.
H.-K. Chung C. Bowen C.J. Fontes S.B. Hansen Yu. Ralchenko 《High Energy Density Physics》2013,9(4):645-652
We present the main results of the 7th Non-Local Thermodynamic Equilibrium Code Comparison Workshop held in December 2011 in Vienna, Austria. More than twenty researchers from nine countries, who actively work on development of collisional-radiative codes for plasma kinetics modeling, attended the meeting and submitted their results for a number of comparison cases. The cases included free-electron-laser-inspired time-dependent relaxation of photoexcited Ne-like Ar, ionization balance and spectra for highly charged tungsten, spectroscopic diagnostics of krypton L-shell spectra, and an investigation of Ne model convergence with principal quantum number. 相似文献
88.
Federico Camia Luiz Renato G. Fontes Charles M. Newman 《Journal of statistical physics》2006,125(5-6):1155-1171
We analyze the geometry of scaling limits of near-critical 2D percolation, i.e., for p = p
c+λδ1/ν, with ν = 4/3, as the lattice spacing δ → 0. Our proposed framework extends previous analyses for p = p
c, based on SLE
6. It combines the continuum nonsimple loop process describing the full scaling limit at criticality with a Poissonian process
for marking double (touching) points of that (critical) loop process. The double points are exactly the continuum limits of
“macroscopically pivotal” lattice sites and the marked ones are those that actually change state as λ varies. This structure
is rich enough to yield a one-parameter family of near-critical loop processes and their associated connectivity probabilities
as well as related processes describing, e.g., the scaling limit of 2D minimal spanning trees. 相似文献
89.
C.J. Fontes J. Abdallah C. Bowen R.W. Lee Yu. Ralchenko 《High Energy Density Physics》2009,5(1-2):15-22
We review the 5th non-LTE kinetics code comparison workshop, held in November 2007. Both steady-state and time-dependent cases for elements ranging from carbon to gold were examined in detail. Calculations of radiative power losses and specific spectra were requested in addition to typical plasma quantities such as the ionization balance. Non-Maxwellian electrons, external Planckian radiation and opacity effects in spectra were also included in the comparisons. We discuss the organization of the workshop and present a set of representative results. The particular case of a tungsten plasma at tokamak operating densities was considered for the first time. Due to its importance to the ITER project, more detailed results of these comparisons will be published elsewhere. 相似文献
90.
We study models of continuous time, symmetric, ℤd-valued random walks in random environments. One of our aims is to derive estimates on the decay of transition probabilities
in a case where a uniform ellipticity assumption is absent. We consider the case of independent conductances with a polynomial
tail near 0 and obtain precise asymptotics for the annealed return probability and convergence times for the random walk confined
to a finite box. 相似文献