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71.
A new sono-electrochemical method for enhanced detoxification of hydrophilic chloroorganic pollutants in water 总被引:8,自引:0,他引:8
Yasman Y Bulatov V Gridin VV Agur S Galil N Armon R Schechter I 《Ultrasonics sonochemistry》2004,11(6):649-372
A new method for detoxification of hydrophilic chloroorganic pollutants in effluent water was developed, using a combination of ultrasound waves, electrochemistry and Fenton's reagent. The advantages of the method are exemplified using two target compounds: the common herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) and its derivative 2,4-dichlorophenol (2,4-DCP). The high degradation power of this process is due to the large production of oxidizing hydroxyl radicals and high mass transfer due to sonication. Application of this sono-electrochemical Fenton process (SEF) treatment (at 20 kHz) with quite a small current density, accomplished almost 50% oxidation of 2,4-D solution (300 ppm, 1.2 mM) in just 60 s. Similar treatments ran for 600 s resulted in practically full degradation of the herbicide; sizable oxidation of 2,4-DCP also occurs. The main intermediate compounds produced in the SEF process were identified. Their kinetic profile was measured and a chemical reaction scheme was suggested. The efficiency of the SEF process is tentatively much higher than the reference degradation methods and the time required for full degradation is considerably shorter. The SEF process maintains high performance up to concentrations which are higher than reference methods. The optimum concentration of Fe2+ ions required for this process was found to be of about 2 mM, which is lower than that in reference techniques. These findings indicate that SEF process may be an effective method for detoxification of environmental water. 相似文献
72.
Reactions of the new acyclic ligand DNBH with RuCl3 · 3H2O, followed by addition of a secondary ligand L (L = PPh3, 1,10-phenanthroline, 2,2-bipyridine, pyridine and 2,4-diaminotoluene), yield six binuclear metal complexes, TR1–TR6. Two different methods were employed: template and a two-step synthesis, both yielding the same complexes. DNBH and its metal complexes were characterised by a combination of spectroscopic, elemental and magnetic susceptibility data. Coordination was found to be through the carbonyl oxygen of amide and phenolic oxygen in the octahedral environment of the metal. DNBH and some of the metal complexes display antibacterial properties. 相似文献
73.
Naji Al Dahoudi Amal AlKahlout Sabina Heusing Petra Herbeck-Engel Rudolf Karos Peter Oliveira 《Journal of Sol-Gel Science and Technology》2013,67(3):556-564
Crystalline indium doped zinc oxide (IZO) nanopowders were synthesized using hydrothermal treatment processing. Increasing the doping ratio of indium in the zinc oxide significantly influences the phase structure and shape of the nanopowders resulting in nanorod to nanoparticulate morphologies. As the doping profile increases, the crystallite size decreases, the band gap energy blue shifts and the specific surface area increases (measured by BET method). Additionally Raman spectroscopy exhibited shifts of several peaks, as well as revealed new peaks, confirming the substitution of indium ions within the zinc oxide lattice sites. An IZO suspension made of IZO nanoparticles (In/Zn = 3 atm.%) with a zeta potential greater than 30 mV at pH = 6 was successfully spin-coated on glass substrates for to make transparent conductive coatings evincing sheet resistances as low as 35 kΩ□ (ρ = 4.9 × 10?3 Ω m,) with transmission in the visible range as high as 90 %. 相似文献
74.
Valentina Pedoia Sabina Strocchi Vittoria Colli Elisabetta Binaghi Leopoldo Conte 《Magnetic resonance imaging》2013
In this study new evaluation strategies for comparing different Statistical Parametric Maps computed from fMRI time-series analysis software tools are proposed. The aim of our work is to assess and quantitatively evaluate the statistical agreement of activation maps. Some pre-processing steps are necessary to compare SPMs (Statistical Parametric Maps), including segmentation and co-registration. The study of the statistical agreement is carried out following two ways. The first way considers SPMs as the result of two classification processes and extracts confusion matrix and Cohen's kappa index to assess agreement. Some considerations will be made on the statistical dependence of classes and a new formulation of kappa index will be used for overcoming this problem. The second way considers SPMs as two 3D images, and computes the similarity of SPMs images with a fuzzy formulation of the Jaccard Index. Several experiments were conducted both to assess the performance of the proposed evaluation tools and to compare activation maps computation pipelines from two widely used software tools in a clinical context. 相似文献
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76.
Sidath Wijesinghe Sabina Maskey Dvora Perahia Gary S. Grest 《Journal of Polymer Science.Polymer Physics》2016,54(5):582-588
The conformation of dinonyl poly para phenylene ethynylenes (PPEs) with carboxylate side chains, equilibrated in solvents of different quality have been studied using molecular dynamics simulations. PPEs are of interest because of their tunable electro‐optical properties, chemical diversity, and functionality which are essential in wide range of applications. The polymer conformation determines the conjugation length and their assembly mode and affects electro‐optical properties which are critical in current and potential uses. This study investigates the effect of carboxylate fraction on PPEs side chains on the conformation of chains in the dilute limit, in solvents of different quality. The dinonyl PPE chains are modeled atomistically, where the solvents are modeled both implicitly and explicitly. Dinonyl PPEs maintained a stretched out conformation up to a carboxylate fraction f of 0.7 in all solvents studied. The nonyl side chains are extended and oriented away from the PPE backbone in toluene and in implicit good solvent, whereas in water and implicit poor solvent, the nonyl side chains are collapsed toward the PPE backbone. Rotation around the aromatic ring is fast and no long range correlations are seen within the backbone. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016 , 54, 582–588 相似文献
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79.
Cold reaction valleys in the radioactive decay of superheavy nuclei 286112, 292114, and 296116 are studied taking Coulomb and Proximity Potential as the interacting barrier. It is found that in addition to alpha particle, 8Be, 14C, 28Mg, 34Si, 50Ca, etc. are optimal cases of cluster radioactivity since they lie in the cold valleys. Two other regions of deep minima centered on 208Pb and 132Sn are also found. Within our Coulomb and Proximity Potential Model half-life times and other characteristics such as barrier penetrability, decay constant for clusters ranging from alpha particle to 68Ni are calculated. The computed alpha half-lives match with the values calculated using Viola-Seaborg-Sobiczewski systematics. The clusters 8Be and 14C are found to be most probable for emission with T 1/2 < 1030 s. The alpha-decay chains of the three superheavy nuclei are also studied. The computed alpha-decay half-lives are compared with the values predicted by Generalized Liquid Drop Model and they are found to match reasonably well. 相似文献
80.
Hu Liu Leon M. Smith II Yunyu Mao Weitao Pan Yong‐Jiang Xu Sabina Burdzovic‐Wizeman 《合成通讯》2013,43(3):347-354
An improved route for the preparation of highly functionalized 5,6‐dihydro‐pyrimido[4,5‐b][1,4]oxazepine 1a in multigram quantities was developed. This new methodology was highlighted by the proper methoxy disposition via a regioselective methylation of 2,4,5‐trihydroxy‐benzaldehyde followed by a magnesium sulfate–promoted cyclization. 相似文献