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151.
Sergiu Macavei Marius Rada Mioara Zagrai Victor Bodnarchuk Radu Balan 《Analytical letters》2018,51(17):2671-2681
Here we combine small angle neutron scattering measurements (SANS) with X-ray diffraction analysis (XRD) and infrared spectroscopy (IR) measurements to obtain information about nanoparticles formed in a series of lead-lead dioxide samples mixed with various CuO concentrations. New vitreous systems with the xCuO???(100?x)[4PbO2???Pb] composition where x?=?0, 30, and 70?mol% CuO were prepared by the melt-quenching method using CuO mixed in suitable proportion with the active electrodes of a disassembled car battery as the starting materials. The X-ray diffraction patterns permit the identification of the metallic Pb phase and the presence of oxidic nanoparticles of the lead and copper ions. By doping with higher CuO contents, the SANS curves have a concave shape indicating inhomogeneities and tendency of phase separation due to formation of nanoparticles of the lead and copper ions in recycled host matrix. The studied samples can be considered as polydispersed systems. The matrix is the solvent and the soluble phase is formed from the oxidic lead and/or copper particles with sizes smaller than 69?Å dispersed either inside the host matrix grains or between the host matrix grains. The formation of the nanoparticles in the host matrix and the knowledge of the type of nanoparticles have a decisive role in applications for the construction of essential components of the automobile batteries. 相似文献
152.
Plutonium isotopic composition and the activities of non-separate transuranic elements:237Np and241Am, are determined in the presence of long lived-fission products traces, by gamma-spectrometric measurements with a Ge-ultrapure
detector. The quantitative values from the gamma-spectra analysis, are presented comparatively to mass-spectrometric data.
This work has been done under AIEA, UNPD 7455/Rom. program. 相似文献
153.
A new copper hydroxydiphosphate Cu3(P2O6OH)2 was synthesized, by soft chemistry. The crystal structure was solved ab initio from X-ray powder diffraction data in the triclinic space group P. The structure is built up from [Cu3O10]infinity zigzag chains linked by P2O6(OH) groups to form a tridimensional framework. The [Cu3O10]infinity chains consist of edge-sharing polyhedra. The structure contains two sorts of copper polyhedra: one CuO6 octahedron and two CuO5 pyramids. Magnetization measurements confirm the presence of divalent copper and suggest antiferromagnetic interactions at low temperature. 相似文献
154.
Z. Moldovan L. Alexandrescu I. Vasilescu L. Radu 《Journal of the Iranian Chemical Society》2006,3(4):305-311
The title compound, 1,2-dihydro-2,2,4-trimethylquinoline (TMQ), is a quinoline family member and is among others used to prevent the oxidative degradation of polymers. TMQ has been characterized by its fluorescence emission. In this work the effects of solvent, acidity, continuous irradiation and the influence of some interferents upon the fluorescence intensity of TMQ were investigated. Under the selected conditions (in propan-1-ol solution at λexcitation/λemission = 334 nm/412 nm), the fluorescence intensity is proportional to the concentration of TMQ over the range 0.05–5 μg ml?1 with a correlation coefficient of 0.9963. The proposed method was applied to the determination of TMQ in synthetic mixtures of polymer additives and specific rubber samples. 相似文献
155.
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158.
I.-L. Popescu H. Y. Aboul-Enein D. V. Napradean G. L. Radu I. G. Tanase 《Accreditation and quality assurance》2001,6(8):376-378
This paper describes the practical implementation of a quality system in the control laboratory of the National Medicines
Agency, Romania, the main aim being the alignment of the requirements of the control of drugs in Romania with European Union
standards. Activity in this field is relatively new in Romania, however, it is of great importance to Romania’s compliance
with international standards.
Received: 13 September 2000 Accepted: 19 February 2001 相似文献
159.
We present a new solution of the Einstein-scalar field system with minimally coupled massless scalar field and nonzero cosmological
constant. The field equations are satisfied on both the four dimensional space and a r = const. three dimensional slice. 相似文献
160.
The paper presents a possible path to the sp(3) BRST Lagrangean formalism for a 1-reducible gauge field theory starting from
the Hamiltonian one. This appears to be not at all a trivial attempt and will allow explanation of the structure of generators
and the form of the master equations in the Lagrangean sp(3) theories. The Freedman-Townsend model, for which a Lagrangean
(covariant) sp(3) theory is important, is presented. 相似文献