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71.
Andra-Rada Iurian Arsenio Toloza Joseph Adu-Gyamfi Constantin Cosma 《Journal of Radioanalytical and Nuclear Chemistry》2013,298(3):1857-1863
The 7Be approach in estimating the erosion rates is based on the assumption that the deposition of 7Be fallout associated with the erosive event is spatially uniform. The objective of the present work was to verify this assumption by assessing the influence of heavy rainfalls on the 7Be spatial distribution in Seibersdorf soils, Austria. Incremental and bulk soil depth profiles were collected from a flat site, undisturbed for the last 9 months prior sampling and with no evidence of erosion or deposition after the occurrence of heavy rains (>30 mm day?1). The mean value of the 7Be areal activities (Bq m?2) measured at 10 different points from the selected area was 312 Bq m?2. This value corresponded to a total rainfall of 295 mm within the last 5 months prior sampling, considering that the highest mass activity of 7Be at soil surface will decay below the minimum detectable activity after 5 months’ time. The resulted coefficient of variation had a value of 19 % showing acceptable spatial variability of 7Be fallout connected with individual storm events on a local scale. 相似文献
72.
Elliptic regularizations for the nonlinear heat equation 总被引:1,自引:0,他引:1
The purpose of this paper is to study two elliptic regularizations for the nonlinear heat equation with nonlinear boundary conditions formulated below. Asymptotic expansions of the order zero for the solutions of these elliptic regularizations are established, including some boundary layer corrections. Under some appropriate smoothness and compatibility conditions on the data estimates for the remainder terms with respect to the C([0,T];L2(Ω)) norm are proved in order to validate these expansions. 相似文献
73.
O. Cozar L. David V. Chis E. Forisz C. Cosma G. Damian 《Fresenius' Journal of Analytical Chemistry》1996,355(5-6):701-702
CuL2X2 (L = 7-chloro-1,3-dihydro-1-methyl-5-phenyl-3H-1,4-benzodiazepin-2-one, also known as diazepam, X = Cl, Br) complexes have been prepared and investigated by ESR spectroscopy. Powder ESR spectra of these complexes suggest a planar-rhombic distorted local symmetry. The CH3Cl solutions spectra show the presence of pseudo-tetrahedral species with a 3dxy+4pz mixture ground state for the paramagnetic electron. The anisotropic spectra obtained for the Cu(II)-diazepam solution adsorbed on NaY zeolite confirm the existence of a CuN2X2 chromophore. 相似文献
74.
L. Daraban C. Cosma T. Fiat O. Cozar M. D. Croitoru 《Fresenius' Journal of Analytical Chemistry》1996,355(3-4):370-371
A nondestructive method has been used for the qualitative and quantitative determination of elements such as Au, Cu, Ag in minerals and especially in golden sand. The induced radioactivity has been analyzed with a high resolution gamma spectrometer containing a Ge(Li) semiconductor detector type and a multichannel analyzer. The samples have been collected from the alluvia of the Mure and Someul Mic river basins, proving the presence of gold and copper in small concentrations. These results have been correlated to previous data showing the existence of some gold mines in these zones. This nondestructive, rapid and highly sensitive method can be used for industrial processes [1] control and prospections. The use of a NaI(Tl) scintillation crystal for routine measurements of the 198Au radioisotope type and the interferences by copper, silver and indium in the irradiated samples are discussed. 相似文献