Photoacoustic (PA) spectra of powdered neodymium oxide (Nd 2O 3 (A type)), neodymium hydrated chloride (NdCl 3·6H 2O) and neodymium fluoride (NdF 3) were reported. PA band shifts as compared to their positio...Photoacoustic (PA) spectra of powdered neodymium oxide (Nd 2O 3 (A type)), neodymium hydrated chloride (NdCl 3·6H 2O) and neodymium fluoride (NdF 3) were reported. PA band shifts as compared to their positions in aqueous Nd 3+ are used to calculate the nephelauxetic parameters of the compounds. The variation of these parameters and correlation with the nature of metal ligand bonding were discussed. A novel method is introduced to determine the relative values of oscillator strengths and Judd Ofelt parameters of powdered samples using PA spectroscopy. It is found that a linear correlation exists between relative values of τ 2 and oscillator strengths of hypersensitive transitions of the title compounds. It is hopetul that the new method of PA technique may serve for the Judd Ofelt quantitative analysis of powdered rare earth compounds.展开更多
Ventricular fibrillation (VF) caused by myo-cardial ischemia is one of the leading factors of death attrib-uted to cardiovascular diseases. It is particularly significantto predict VF and gain valuable time for clinic...Ventricular fibrillation (VF) caused by myo-cardial ischemia is one of the leading factors of death attrib-uted to cardiovascular diseases. It is particularly significantto predict VF and gain valuable time for clinic therapy. Five dogs are taken as the research objects and a VF model is introduced. The nonlinear characteristics of the ECGs before and after VF are investigated with nonlinear multi-parame-ter analysis methods, Gaussian kernel (GK) correlation es-timation algorithm and Lyapunov exponent estimation algo-rithm. Correlation entropy h2 is also presented. The results indicate that there are three parameters which will change at the same time with the conditions of myocardial ischemia,and any changes of a single parameter may be caused byother factors and mislead the judgment. Multi-parameter analysis is more reliable to reveal the heart conditions, and to predict VF without misjudgments.展开更多
The acoustic resonance scattering spectrum of a porous sphere embedded in an elastic matrix is studied based on the resonance scattering theory (RST) proposed by Flax et al. Taking nodular cast iron as an example, som...The acoustic resonance scattering spectrum of a porous sphere embedded in an elastic matrix is studied based on the resonance scattering theory (RST) proposed by Flax et al. Taking nodular cast iron as an example, some numerical computations are made for acoustic backscattering and resonance scattering spectra of certain partial waves. The change of acoustic resonance frequencies of different modes as a function of the porosity of porous spherical scatterers is also simulated.展开更多
文摘Photoacoustic (PA) spectra of powdered neodymium oxide (Nd 2O 3 (A type)), neodymium hydrated chloride (NdCl 3·6H 2O) and neodymium fluoride (NdF 3) were reported. PA band shifts as compared to their positions in aqueous Nd 3+ are used to calculate the nephelauxetic parameters of the compounds. The variation of these parameters and correlation with the nature of metal ligand bonding were discussed. A novel method is introduced to determine the relative values of oscillator strengths and Judd Ofelt parameters of powdered samples using PA spectroscopy. It is found that a linear correlation exists between relative values of τ 2 and oscillator strengths of hypersensitive transitions of the title compounds. It is hopetul that the new method of PA technique may serve for the Judd Ofelt quantitative analysis of powdered rare earth compounds.
文摘Ventricular fibrillation (VF) caused by myo-cardial ischemia is one of the leading factors of death attrib-uted to cardiovascular diseases. It is particularly significantto predict VF and gain valuable time for clinic therapy. Five dogs are taken as the research objects and a VF model is introduced. The nonlinear characteristics of the ECGs before and after VF are investigated with nonlinear multi-parame-ter analysis methods, Gaussian kernel (GK) correlation es-timation algorithm and Lyapunov exponent estimation algo-rithm. Correlation entropy h2 is also presented. The results indicate that there are three parameters which will change at the same time with the conditions of myocardial ischemia,and any changes of a single parameter may be caused byother factors and mislead the judgment. Multi-parameter analysis is more reliable to reveal the heart conditions, and to predict VF without misjudgments.
基金National Natural Science Foundation of China(10174037)
文摘The acoustic resonance scattering spectrum of a porous sphere embedded in an elastic matrix is studied based on the resonance scattering theory (RST) proposed by Flax et al. Taking nodular cast iron as an example, some numerical computations are made for acoustic backscattering and resonance scattering spectra of certain partial waves. The change of acoustic resonance frequencies of different modes as a function of the porosity of porous spherical scatterers is also simulated.
