RESUMO
The oscillator strengths and cross sections of the valence-shell excitations of HBr were determined by fast electron scattering with an incident electron energy of 1500 eV and an energy resolution of 80 meV. The momentum transfer dependence behaviors of the generalized oscillator strengths have been used to elucidate the transition characteristics. The present results show that the strong spin-orbital interaction results in the observation of some triplet states in the (Λ, S) coupling and the constant generalized oscillator strength ratios for the pair states with the same electronic configuration and quantum number Ω, and the quantitative spin-orbit coupling coefficients of b3Π1(v = 0) and C1Π(v = 0) are determined. The optical oscillator strengths of the valence-shell excitations were obtained by extrapolating the generalized oscillator strengths to the limit of zero squared momentum transfer. The present optical oscillator strengths give an independent cross-check of the previous experimental and theoretical results, and the comparison shows that the line-saturation effect is more severe for the high Rydberg states with large intensities and narrow natural widths. The integral cross sections of the valence-shell excitations of HBr were obtained from the excitation threshold to 5000 eV by the BE-scaling method. The present oscillator strengths and cross sections supplement the fundamental molecular database of HBr and can be used for modeling in the semiconductor industry, astrophysics, and atmospheric chemistry.
RESUMO
A joint experimental and theoretical investigation of the valence shell excitations of carbon tetrachloride has been performed by fast electron scattering and time dependent density functional theory calculations. At a collision energy of 1.5 keV and an energy resolution of about 70 meV, the dipole-forbidden transition of a1σ* â 2t1 has been clearly observed at large momentum transfers, and its excitation energy of 6.15 eV and line width of 0.72 eV have been determined. Two new features are also recognized at 9.97 and 10.26 eV. The generalized oscillator strengths of the excited states at 5-11.3 eV have been determined from the measured spectra. The calculated generalized oscillator strength of the a1σ* â 2t1 transition with the vibronic effect shows better agreement with the experiment, and the vibronic effect also accounts for its nonzero intensity at zero squared momentum transfer. The optical oscillator strengths of the valence shell excitations have also been obtained by extrapolating the generalized oscillator strengths to the limit of zero squared momentum transfer. The integral cross sections have been systematically determined from the threshold to 5000 eV by means of the BE-scaling method. The present oscillator strengths and cross sections provide the fundamental data of carbon tetrachloride and have important applications in photochemical modeling for atmospheric physics.
RESUMO
OBJECTIVE: To observe the effect and mechanism of Chinese herbs in the treatment of taeniasis. METHODS: Five hundred and forty-eight cases of taeniasis were treated with Binlang Chengqi Decoction (BLCQD). The tapeworm scolices of ten cases were observed by electron microscope (EM). RESULTS: Among the 548 cases, 521 cases were cured and 27 cases were improved. The total effective rate was 100%. Foam-like secretion in the sucker of the tapeworm scolices and erosion of the epithelium in the cervical part were observed by scanning electron microscope. Observed by transmission electron microscope, the cortex was seriously damaged. The microvilli were exfoliated. The cells in the muscle layer and parenchyma layer were injured in various degrees. The mitochondria were tumefied or caved. And the nerve cord was damaged. CONCLUSION: BLCQD can not only paralyze the tapeworm scolex, but also injury the cells of the tapeworm scolex.
