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The formation of charge transfer complexes with 1:1 and 2:1 stoichiometries (acceptor-to-donor) between DDQ and 1,10-diaza-18-crown-6 in chloroform solution was investigated spectrophotometrically. The stepwise formation constants of the resulting complexes were evaluated from the non-linear least-squaresfitting of the absorbance-mole ratio data. The enthalpies and entropiesof the complexation reactions were determined from the temperature dependence of the stepwise formation constants. The resulting 1:1 and 2:1 complexes were isolated in crystalline form and characterized. The results are consistent with the ionic structure of the resulting charge transfer complexes.  相似文献   
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Using B3LYP/6-31G* density functional level of theory, the structural and optical properties of the C60 and M@C59X cages have been investigated. Results indicate that the charge on C atoms and band gap of C60 cage are changed dramatically with the substitution of one B or N atom at one of the C sites and the Li and Na atom encapsulations in the C60 cage. The Mulliken analyses show that the charge is transferred completely between the alkali atoms and the C59X cage. The substitutional and encapsulation doping (SED) reduce the optical gaps of the C60 cage. Also, the oscillator strengths of the absorption peaks are dependent on dopant types.  相似文献   
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In this paper the photonuclear interaction induced by 10 MeV electron beam generating high-intensity neutrons is studied. Since the results depend on the target material, the calculations are performed for Pb, Ta and W targets which have high Z, in a simple geometry. MCNPX code has been used to simulate the whole process. Also, the results of photon generation has been compared with the experimental results to evaluate the reliability of the calculation. The results show that the obtained neutron flux can reach up to 1012 n/cm2/s with average energies of 0.9 MeV, 0.4 MeV and 0.9 MeV for these three elements respectively with the maximum heat deposited as 3000 W/c3, 4500 W/c3 and 6000 W/c3.  相似文献   
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