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21.
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
22.
23.
A series ofc-axis oriented YBa2Cu3O
x
-films with different oxygen content were prepared by laser deposition. The oxygen contentx was determined by X-ray diffraction and by resonant Rutherford-back-scattering (RRBS) measurements. Thec-axis length in these films of YBa2Cu3O
x
is about 0.5% larger compared to bulk values. We describe transport measurements in magnetic fields up to 7 Tesla between room temperature andT
c
in samples with an oxygen content between the orthorhombic-to-tetragonal transition (x6.4) and full oxygenation (x7). The ratio /R
H
was investigated with respect to the two-dimensional Luttinger liquid theory and the model of the two-dimensional ionic metal. We report on deviations from the expected quadratic temperature behaviour of /R
H
, especially in films with high oxygen content. 相似文献
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27.
J. Vaupotić 《Journal of Radioanalytical and Nuclear Chemistry》2001,247(2):291-295
On the territory of the abandoned uranium mine irovski vrh, Slovenia, indoor radon and gamma dose rate measurements were carried out in nineteen schools from February 10 to May 10, 1995, using scintillation cells and etched track detectors for radon and thermoluminescence dosimeters for gamma-ray detection. In five schools indoor radon levels exceeded 400 Bq·m-3, which is the proposed Slovene action level. The maximum average radon value of 1600 Bq·m-3 and the maximum gamma-dose rate of 172 Sv·month-1 were found in the same school. According to the ICRP 65 methodology, annual effective doses from radon decay products ranged from 0.05 to 6.10 mSv for pupils and from 0.04 to 4.90 mSv for teachers. Gamma dose rates ranged from 0.05 to 0.19 mSv·y-1 for pupils and from 0.07 to 0.27 mSv·y-1 for teachers. 相似文献
28.
Nada Majkić-Singh Milan Konjović Marina Stojanov Slavisa Spasić Ivan Berkeš 《Analytica chimica acta》1981,130(2):419-423
Hydrogen peroxide, the product of diamine oxidase-catalyzed putrescine or cadaverine oxidation, formed in proportion to the enzyme activity, is measured spectrophotometrically by using the above sulfonate (ABTS) and peroxidase. Only one reagent solution containing 3 mmol of putrescine or 10 mmol of cadaverine, 4 mmol of ABTS and 3000 U of peroxidase per litre of 0.2 mol l-1 Tris—0.1 mol l-1 HCl buffer pH 7.5 is needed. Absorbance changes are measured at 410 nm over the first 3 min of the reaction. This initial oxidation rate of the chromogen enables diamine oxidase activity up to 230 U l-1 to be determined. 相似文献
29.
It has been shown that the depotarisation end-point technique, based on the phenomenon of a sudden out-of-balance current, produced by the establishment of a new redox potential at the indicator electrode in a pre-balanced circuit, can also be applied to precipitation titrations. The use of a platinum indicator electrode instead of one made of silver, and determination in very dilute solution, yield better results than those obtained using the classical potentiometric method. 相似文献
30.
Milivoj Lovrić 《Journal of Electroanalytical Chemistry》1981,123(2):373-378
Recently proposed chemically prepared electrodes are coated with a thin, permeable, insulating, inert film which does not react with the depolarizer, does not allow depolarization on its surface and does not change the standard constant of the depolarization rate. It only changes the diffusion coefficient of a certain ion near the surface of the electrode. In this article, the theory of a reversible reduction of a simple ion at a film-coated stationary planar electrode is developed. If the film thickness is comparable with a diffusion layer thickness, considerable changes on the i-t curves can occur, but the position of the half-wave potential will remain constant. 相似文献