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11.
Urška L. Štangar Urh Černigoj Polonca Trebše Ksenija Maver Silvia Gross 《Monatshefte für Chemie / Chemical Monthly》2006,137(5):647-655
Summary. Transparent TiO2 films with a high photodegradation activity towards an azo dye in aqueous solution were prepared by sol–gel processing. Films
on soda–lime glass supports protected with a thin silica barrier layer exhibited better crystallization and monodisperse nanoparticles,
higher absorption of light below 370 nm, and higher photocatalytic activity than those films deposited on bare glass supports
proving the detrimental effect of interdiffused sodium ions on the development of the anatase nanostructure. The effect of
substrate was more pronounced in thinner films (300 nm) than in thicker ones (1200 nm), which were achieved by adding a template
(i.e. Pluronic F127) to the sol. 相似文献
12.
The reduction of Ni2+ ions at mercury electrodes in acidic perchlorate solutions, at perchlorate concentrations below 0.2 M, is characterized by absence of kinetic control in the preceding step, and by a complex reaction mechanism following the electron transfer. This reaction sequence is known to involve intermetallic compound formation between Ni and Hg and is best described, as shown here, by a parallel second and third order kinetic scheme. Apparent rate coefficients for this kinetic scheme were determined using cyclic chronopotentiometric data and fitting by digital simulation. A linearization test of computed kinetic rate coefficients versus the number of transitions permits quantitative tests of validity of assumptions made. 相似文献
13.
Summary The effect of pre-adsorbed benzene and ethanol on the adsorptive properties of natural zeolite (clinoptilolite) has been studied
by gas-solid chromatography. It has been shown that modification of the solid surface by volatile organics has a significant
influence on the adsorptive properties. The modification is of the same order as the more difficult modification by inorganics,
as illustrated here by clinoptilolite modification with Co2+. Energy distribution of surface adsorptive sites appears to be continuous and confirms previous finding that only a small
proportion of active sites is responsible for most adsorbate retention.
Part II reference [4] 相似文献
14.
Laila H. Abdel-Rahman 《Transition Metal Chemistry》2006,31(7):943-950
A new series of N-phthaloylglycineate (N-phthgly) ternary complexes of cobalt(II) and nickel(II) with imidazole (imi), N-methylimidazole
(mimi) and 2,2′-bipyridyl (bipy) have been synthesized and characterized by elementary analyses, IR spectroscopy, thermogravimetric
analysis. X-ray crystal structure analyses of the three complexes of [Co(mimi)2(N-phthgly)2] (1), [Co(bipy)(OH2)4](N-phthgly)2
(2) and [Ni(imi)2(N-phthgly)2(OHCH3)2] (3) were also carried out. In complex (1), the Co(II) exists in a distorted tetrahedral enviroment, where two nitrogen atoms of two methylimidazole molecules and two
oxygen atoms of the carboxylate group of two N-phthaloylglycinate molecules are coordinated. On the other hand, in complex
(2) the cobalt atom coordinates a 2,2′-bipyridine molecule and four water oxygen atoms forming a distorted octahedral conformation.
A molecule of N-phthaloylglycinate is connected by van der waals contact and H-bonds. For complex (3), the nickel atom is surrounded by four oxygens (two oxygens of two different N-phthaloylglycinate molecules and two of methanol
ligand) in the basal plane of octahedron along with two imidazole nitrogen atoms at the apical positions. Strong intramolecular
H-bond exists between the uncoordinated carboxylic oxygen of the N-phthaloylglycinate ligand and the O–H of the methanol group. 相似文献
15.
Electrodes containing glucose oxidase or xanthine oxidase adsorbed on modified glassy carbon electrodes or on conductive complexes, accumulate charge in the presence of substrates, the discharge of which gives the chronoamperometric stripping current. This current is 15 times higher than the stationary current after preconcentration for 8 min. A ten-fold increase in sensitivity of the determination of glucose or hypoxanthine is observed. The stripping current of electrodes based on cytochrome b2 adsorbed on a graphite electrode is 25 times higher than the stationary current. The electrode is useful for lactate determinations for more than 7 days. 相似文献
16.
Dubravka Matković-Čalogović Zora Popović Branka Korpar-Čolig 《Journal of chemical crystallography》1995,25(8):453-458
[Hg(terpy)2](CF3SO3)2·0.5(CH3)2CO crystallizes in the triclinic
space group witha=14.631(6),b=15.258(4),c=18.785(7) Å, =69.66(2), =70.72(1), =88.55(1)°. The crystal structure consists of two independent [Hg(terpy)2]2+ cations, four trifluoromethanesulfonate anions and an acetone molecule in the asymmetric unit. Each mercury atom is coordinated by two tridentate terpyridine ligands forming an irregular six-coordination polyhedron. The Hg–N bond lengths range from 2.27(2) to 2.53(2) Å. 相似文献
17.
The electrical resistivity of as deposited polycrystalline copper thin films as a function of varying the process parameters has been investigated. Trying to minimize the resistivity of the copper thin films is important in the semiconductor industry, due to the fact that low resistivity copper can be employed to great advantage for new metallization schemes in advanced ultralarge scale integrated circuits. This paper presents the optimum choice of parameters that are necessary to achieve low resistivities of the thin films in reproducible experiments. All the depositions were performed using an unbalanced d.c. planar magnetron sputtering source (consisting of a circular copper target (98% purity, 0.01% Fe, 0.005% Ni, 0.005% Si) with a diameter of 100mm fitted with two electromagnets). The copper thin films were deposited onto glass substrates with argon being used as the sputtering gas. The resistivity was studied as a function of the pressure of the sputtering gas, the substrate bias, the substrate to target distance, the magnetron power, and the substrate temperature. It was found that depositions producing thin films with a resistivity of that approaching the bulk material (1.7×10–8m) were obtained if the sputtering gas pressure was below 0.2 Pa. The effect of the substrate bias was insignificant at these pressures. The crystallographic structure of the copper thin films, determined by X-ray diffraction, is also reported.The authors would like to thank Dr. Soukup for his support during this research. We would also like to express our gratitude to Mr. A. Rajský for improving the design of the sputtering device. This work was partially financed by a grant from the Grant Agency of the Czech Republic No. 202/93/0508. 相似文献
18.
19.
N. Kallay M. Čolić D. W. Fuerstenau H. M. Jang E. Matijević 《Colloid and polymer science》1994,272(5):554-561
Potentiometric, electrokinetic, and coagulation experiments with a rutile dispersion in the pH region above the point of zero charge exhibit an inverse lyotropic sequence for counterions: Li+>K+>Cs+. The potentiometric and electrokinetic data were interpreted by a surface complexation model assuming the Stern-Gouy-Chapman structure of the interfacial layer, which yielded the values of inner layer capacitances,C, and the intrinsic equilibrium constants,K
ass
0
, characterizing the specificity of each counterion. These parameters were used to explain the order of lyotropic sequences in the adsorption, coagulation, and electrokinetic phenomena. 相似文献
20.
Precise values of energies and widths of low-lying resonances in some rare-gas atom systems (Ar-Ar, Ne-Kr, Ne-Xe) are reported. 相似文献