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51.
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[reaction: see text] The palladium-catalyzed coupling of aryl iodides and arenesulfinates provides a simple and extremely efficient new route to unsymmetrical diaryl sulfones, usually isolated in high yield. The reaction tolerates a variety of functionalized aryl iodides, including those containing ether, ester, and nitro groups. The best results have been obtained by using Pd(2)(dba)(3), Xantphos, Cs(2)CO(3), and (n)Bu(4)NCl in toluene at 80 degrees C. 相似文献
53.
This paper discusses the partitioning of metals (K, Na, Ca, Mg, Al, Cu, Fe, Pb and Zn) between the aqueous phase and the suspended insoluble material in fog samples collected in the Po Valley during two extensive fields campaigns. Metals represent on average 11% of the mass of suspended insoluble matter, while the main component is carbon (both organic carbon, OC = 35%, and black carbon, BC = 8%). The unaccounted suspended matter mass is very high, on average 46%, and is attributable to non metallic species, such as O and N and of Si. The principal metals in the insoluble suspended fraction are Fe and Al (2-5%), while the contributions of other metals (Na, Mg, Cu, Pb and Zn) are lower than 1%. Ca and K exhibited high blank values and could not be detected above blank detection limit threshold. The main components in the aqueous phase are NO3- (34%), WSOC (23%), SO4(2-) (18%) and NH4+ (19%), while trace metals and remaining cations and anions accounted for less than 1% of solute mass. The main dissolved trace metals in fog droplets are Zn, Al and Fe, while the main metallic cations are Na and Ca. Fe and Al are the only metals preferentially distributed in the suspended insoluble matter of fog droplets (partitioning ratio respectively 37% and 33%). All other metals are mostly dissolved in the aqueous phase (mean partitioning ratios of Mg, Pb, Zn, Cu and Na are 69%, 70%, 77%, 81% and 87%). These findings are in agreement with literature data on metal speciation in cloud and rain samples. The dependence of partitioning ratios on pH is investigated for the different metals, with only Al showing a clear partitioning ratio decrease with increasing pH. Conversely, the other metals show no dependence or a complex and highly variable behaviour. The partitioning ratio of iron (mean 37%) observed in the Po Valley fog samples is much higher than the water extractable iron in aerosol particles (typically 1-2 %): this fact can be explained by differences in the aerosol sources and composition among sites and by chemical processes in the aqueous phase, such as complexation and redox reactions involving organic ligands (oxalate, or other organic acids as humic-like organic matter) which may promote Fe solubility. 相似文献
54.
6-Trifluoromethyl-12-acylindolo[1,2-c]quinazolines are prepared in high yield through the palladium-catalyzed reaction of bis(o-trifluoroacetamidophenyl)acetylene with aryl or vinyl halides and triflates. The reaction, which tolerates a variety of important functional groups, probably involves the formation of a 3-acyl-2-(o-trifluoroacetamidophenyl)indole intermediate, followed by its cyclization to the indoloquinazoline product. [reaction: see text] 相似文献
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Activated carbon with high surface area was prepared from sodium salt of carboxyl methyl cellulose by physical activation at 400 °C followed by treatment in boiling water. The carbon was characterized by XRD, SEM, EPR, TG, IR, surface areas and porosity measurements. The carbon showed alkaline reaction in aqueous solution. It showed high surface area and pore volume in comparison to two commercially available carbons. 相似文献
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Sandro Donadi Angelo Bassi Catalina Curceanu Antonio Di Domenico Beatrix C. Hiesmayr 《Foundations of Physics》2013,43(7):813-844
Collapse models predict the spontaneous collapse of the wave function, in order to avoid the emergence of macroscopic superpositions. In their mass-dependent formulation, they claim that the collapse of any system’s wave function depends on its mass. Neutral K, D, B mesons are oscillating systems that are given by Nature as superposition of two distinct mass eigenstates. Thus they are unique laboratory for testing collapse models that are sensitive to the mass. In this paper we derive—for the single mesons and bipartite entangled mesons—the effect of the mass-proportional CSL (Continuous Spontaneous Localization) collapse model on the dynamics on neutral mesons. We compare the theoretical prediction with experimental data from different accelerator facilities. 相似文献
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