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61.
The Effect of the Modification of Carbon Spheres with ZnCl2 on the Adsorption Properties towards CO2
Iwona Peech Piotr Staciwa Daniel Sibera Ewelina Kusiak-Nejman Antoni W. Morawski Joanna Kapica-Kozar Urszula Narkiewicz 《Molecules (Basel, Switzerland)》2022,27(4)
Zinc chloride and potassium oxalate are often applied as activating agents for carbon materials. In this work, we present the preparation of ZnO/carbon spheres composites using resorcinol-formaldehyde resin as a carbon source in a solvothermal reactor heated with microwaves. Zinc chloride as a zinc oxide source and potassium oxalate as an activating agent were applied. The effect of their addition and preparation conditions on the adsorption properties towards carbon dioxide at 0 °C and 25 °C were investigated. Additionally, for all tested sorbents, the CO2 sorption tests at 40 °C, carried out utilizing a thermobalance, confirmed the trend of sorption capacity measured at 0 and 25 °C. Furthermore, the sample activated using potassium oxalate and modified using zinc chloride (a carbon-to-zinc ratio equal to 10:1) displayed not only a high CO2 adsorption capacity (2.69 mmol CO2/g at 40 °C) but also exhibited a stable performance during the consecutive multicycle adsorption–desorption process. 相似文献
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The Perkin reaction catalyzed by tertiary amines is found to run not according to the aldol-type condensation mechanism but according to the mechanism in which the first stage is the formation and cycloaddition of ketene, yielding a β-lactone, which cleaves to the unsaturated acid. 相似文献
66.
A Sandstr?m M Kwiatkowski J Chattopadhyaya 《Acta chemica Scandinavica. Series B: Organic chemistry and biochemistry》1985,39(4):273-290
A synthesis of a pentaribonucleotide fragment constituting the residues 59-63 of 3'-terminus of E. coli tRNAIle, 5'-ApGpUpCpC-3', has been carried out using a new, easily accessible and achiral 2'-ketal protecting group. The new 2'-ketal group has an additional advantage in that it is easily functionalized to the diamide with aqueous ammonia in the penultimate step of deblocking of fully protected oligoribonucleotides. Such a functionalization of the 2'-ketal group at the penultimate step of deblocking of the fully protected tRNA molecule enhances its relative rate of removal under an acidic condition with a minimum of damage of the target tRNA molecule. 相似文献
67.
A new pentadentate Schiff base 2,6,10-triaza-1,11-bis(2′-aminophenyl)-undeca-1,10-diene, abaDPT, and its complexes of general formula M(abaDPT)X2 where M = Cu(II), Ni(II), X = Cl, Br, I, NO3 and ClO4, have been prepared. The complexes have been characterized by electronic and IR spectra, EPR, magnetic moments, molar conductances, and elemental analysis. IR data show an interaction between halide anion of the outer coordination sphere and the complexed amino group. EPR and spectrophotometric data of most of the copper compounds are consistent with a distorted square pyramidal geometry. Single crystal EPR studies of Cu(abaDPT)(NO3)2 and Cu(abaDPT)Br2 revealed that copper atoms in the former compound occupy two magnetically inequivalent places in the lattice while copper atoms in the latter compound take identical sites. Principal g tensor axes of the two compounds have been determined. 相似文献
68.
Zuin M Cavazzana R Martines E Serianni G Antoni V Bagatin M Andrenucci M Paganucci F Rossetti P 《Physical review letters》2004,92(22):225003
Measurements of magnetic and electrostatic fluctuations in an applied field magneto-plasma-dynamic thruster have shown that a m/n=1/1 kink mode becomes unstable whenever the Kruskal-Shafranov limit is violated. A positive correlation is established between the kink and performance degradation at high current, which has until now prevented the use of this kind of thruster in space missions. 相似文献
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Breakup densities of hot 197Au-like residues have been deduced from the systematic trends of Coulomb parameters required to fit intermediate-mass-fragment kinetic-energy spectra. The results indicate emission from nuclei near normal nuclear density below an excitation energy E(*)/A less, similar 2 MeV, followed by a gradual decrease to a near-constant value of rho/rho(0) approximately 0.3 for E(*)/A greater, similar 5 MeV. Temperatures derived from these data with a density-dependent Fermi-gas model yield a nuclear caloric curve that is generally consistent with those derived from isotope ratios. 相似文献