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941.
In this paper, according to the molecular fragment principle, a series of eight ternary luminescent lanthanide complex systems were assembled, and whose compositions were determined with elemental analysis and infrared spectrum: Ln(MA)3(L)·H2O, where Ln = Sm, Eu, Tb, Dy; HMA = α‐methylacrylic acid; L = 1,10‐phenanthroline (phen), 2,2′‐bipyridine (bipy). The photophysical properties of these functional molecular systems were studied with ultraviolet‐visible absorption spectrum, and fluorescence excitation and emission spectrum. It was found that the heterocylic compounds (phen and bipy) act as the main energy donor and luminescence sensitizer for their suitable energy match and effective energy transfer to the emission energy level of Ln3+ ions. MMA ligand was only used as the terminal structural ligand to influence the luminescence. Especially terbium complex systems show the strongest luminescence for the optimum energy match and transfer between phen (bipy) and Tb3+ ion. 相似文献
942.
A new, high performance liquid chromatography method has been developed for the separation of monovinyl- and divinyl-protochlorophyllides, using commercially available, C30 reverse phase column and isocratic elution. This method can be used both for analytical applications and preparative scale purification of monovinyl- and divinyl-protochlorophyllides using the same column where submilimolar concentrations of the crude protochlorophyllide extract can be separated in one run. The purity of the obtained protochlorophyllides was demonstrated by spectroscopic methods, as well by the formation of aggregates in toluene. 相似文献
943.
944.
Electroconductivity of BaCe0.9Nd0.1O3−α was studied as a function of the composition of the H2+H2O+Ar mixture and temperature in the interval from 873 to 1173 K. It was shown that the electroconductivity was independent
of PH2 (0.97 to 0.10 atm) and PO2 (10−21 to 10−26 atm), but depended on PH2O (0.08 to 0.005 atm). A mathematical processing of the PH2O dependencies of the electroconductivity, which was performed in terms of a classical model of defect formation in high-temperature
proton-conducting solid electrolytes, yielded equilibrium constants of the reaction of water dissolution in BaCe0.9Nd0.1O3−α and mobilities of protons and oxygen ions. The temperature dependencies of these quantities were used to determine the mobility
activation energies of protons (Ea=34±7 kJ/mole) and oxygen ions (Ea=72±8 kJ/mole), and also the enthalpy (ΔH=−150±25 kJ/mole) and the entropy (ΔS=153±26 kJ/mole·K) of the reaction of water
dissolution in BaCe0.9Nd0.1O3−α. 相似文献
945.
946.
We exactly calculate the fourth virial coefficient for hard spheres in even dimensions for D = 4, 6, 8, 10, and 12. 相似文献
947.
We introduce a dynamic force spectroscopy technique enabling the quantitative measurement of conservative and dissipative tip-sample forces in ambient conditions. In difference to the commonly detected force-vs-distance curves dynamic force microscopy allows to measure the full range of tip-sample forces without hysteresis effects caused by a jump-to-contact. The approach is based on the specific behavior of a self-driven cantilever (frequency-modulation technique). Experimental applications on different samples (Fischer-sample, silicon wafer) are presented. 相似文献
948.
W. Meile E. Reisenberger M. Mayer B. Schmölzer W. Müller G. Brenn 《Experiments in fluids》2006,41(6):949-964
The aerodynamic behaviour of a model ski jumper is investigated experimentally at full-scale Reynolds numbers and computationally applying a standard RANS code. In particular we focus on the influence of different postures on aerodynamic forces in a wide range of angles of attack. The experimental results proved to be in good agreement with full-scale measurements with athletes in much larger wind tunnels, and form a reliable basis for further predictions of the effects of position changes on the performance. The comparison of CFD results with the experiments shows poor agreement, but enables a clear outline of simulation potentials and limits when accurate predictions of effects from small variations are required. 相似文献
949.
M. I. Oshtrakh O. B. Milder V. A. Semionkin L. I. Malakheeva P. G. Prokopenko 《Journal of Radioanalytical and Nuclear Chemistry》2006,269(3):671-677
Summary Characterization of iron storage proteins in liver and spleen from normal chicken and chicken with lymphoid leukemia in comparison
with human liver ferritin were considered by M?ssbauer spectroscopy (preliminary results). Small differences in M?ssbauer
hyperfine parameters for both normal and lymphoid leukemia chicken liver and spleen were observed. The value of quadrupole
splitting for human liver ferritin was higher than those for chicken tissues. A decrease of iron content in lymphoid leukemia
chicken tissues was also found, however, the reason of this fact (pathology or feeding) was not clear yet. 相似文献
950.