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41.
A versatile palladium catalyst system for Suzuki-Miyaura coupling of alkenyl tosylates and mesylates
Wong PY Chow WK Chung KH So CM Lau CP Kwong FY 《Chemical communications (Cambridge, England)》2011,47(29):8328-8330
A general and effective palladium system for Suzuki-Miyaura coupling of alkenyl electrophiles under mild reaction conditions is reported. With the Pd(OAc)(2)/CM-phos system, a variety of alkenyl tosylates are coupled well with ArB(OH)(2). Moreover, the first successful examples of using alkenyl mesylates in alkenylation are also described. 相似文献
42.
C. Tănase Lucia Odochian N. Apostolescu A. Pui 《Journal of Thermal Analysis and Calorimetry》2011,103(3):1079-1085
The article is devoted to the study on the thermal behaviour of three species of edible mushrooms: Boletus edulis (foot and cap), Pleurotus ostreatus (foot and cap), Lactarius deterrimus (cap) by the TG–FTIR-coupled technique, in air, over the 30–900 °C temperature range. The analysis of the TG–DTG–DTA curves
reveals the thermal degradation mechanism to be complex and specific to every species under the recording conditions applied.
A similar degradation mechanism is noticed for the foot and cap of Pleurotus ostreatus in comparison with the Boletus edulis and Lactarius deterrimus species where the mechanisms are different. The TG–FTIR analysis, combustion heats and IR spectra of the starting samples
also support these results. The initial degradation temperatures from TG–DTG indicate the temperature range where these species
are thermally stable and their nutrient features maintained making them proper for food. The TG–FTIR analysis gives information
on the gaseous species evolved by the thermal degradation bringing thus a contribution to the elucidation of the changes developing
by processing the edible mushrooms (industrialization, conservation, culinary preparations, etc.) at temperatures above the
initial degradation temperature. At the same time, the environmental impact, when the mushroom failed cultures are burned,
is also important. 相似文献
43.
测定了Gemini表面活性剂在pH值为10.86,NaBr浓度为1.0mol/L的溶液气/液界面上的表面压一分子面积的等温线。用自制的Brewster角显微镜(BAM)观察了由Gemini表面活性剂在界面上所形成单分子膜的微区形貌随表面压的变化。结果表明:当pH值为10.86时,Gemini表面活性剂在1.0mol/L NaBr溶液的气/液界面上生成了凝聚态的单分子膜;当表面压较低时,观察到在界面上形成了同心圆结构;随着表面压的增加,这些同心圆可发生聚并而形成多中心结构。 相似文献
44.
We give a stability and error analysis of linearly implicitone-step methods for time discretization of non-linear parabolicequations. We derive precise error bounds for Rosenbrock andW-methods, and we explain the error reduction by Richardsonextrapolation of the linearly implicit Euler method which occursin spite of the breakdown of asymptotic expansions. The parabolicequations are studied in a Hilbert space framework that includessemilinear and quasilinear parabolic equations, and also stiffreaction-diffusion equations with reactions at different timescales. 相似文献
45.
Journal of Nanoparticle Research - 相似文献
46.
47.
Let ρ21,…,ρ2p be the squares of the population canonical correlation coefficients from a normal distribution. This paper is concerned with the estimation of the parameters δ1,…,δp, where , i = 1,…,p, in a decision theoretic way. The approach taken is to estimate a parameter matrix Δ whose eigenvalues are δ1,…,δp, given a random matrix F whose eigenvalues have the same distribution as , i = 1,…,p, where r1,…,rp are the sample canonical correlation coefficients. 相似文献
48.
CH. Karpfinger 《Abhandlungen aus dem Mathematischen Seminar der Universit?t Hamburg》2005,75(1):137-161
Zusammenfassung After a short introduction to the valuation theory of nearfields, we give criteria for when a valuation of a skewfield F is
also a valuation of the Dickson nearfield FK which is derived from F by the coupling K on F. For the construction of examples, a rational function field F =K(t) is given.
The set
of all prolongations of a valuation v on K to F is well known. Sufficient conditions are given which guarantee that couplings
K on F and elements
are in this sense compatible so that w is a valuation of the Dickson nearfield FK. Examples demonstrate the results.
相似文献
49.
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