The energy response calibration of the commonly used high pressure ionization chamber is very difficult to obtain when the gamma-ray energy is more than 3 MeV. In order to get the calibration of the higher part of the...The energy response calibration of the commonly used high pressure ionization chamber is very difficult to obtain when the gamma-ray energy is more than 3 MeV. In order to get the calibration of the higher part of the high pressure ionization chamber, we use the Fluka Monte Carlo program to perform the energy response in both the spherical and the cylindrical high pressure ionization chamber which are full of argon gas. The results compared with prior study when the gamma-ray energy is less than 1.25 MeV. Our result of Monte Carlo calculation shows agreement with those obtained by measurement within the uncertainty of the respective methods. The calculation of this study is significant for the high pressure ionization chamber to measure the high energy gamma-ray.展开更多
Within the approximations of spherical lattice cell, central-field, and relativistic Fermi statis- tics, an algorithm with average atom model is presented to calculate the electronic energy levels and equation of stat...Within the approximations of spherical lattice cell, central-field, and relativistic Fermi statis- tics, an algorithm with average atom model is presented to calculate the electronic energy levels and equation of state for hot and dense matter at arbitrary densities and temperatures. Choosing Zink's analytical potential as initial potential, we have solved the Dirac-Slater equation which satisfies the Weigner-Seitz boundary condition. The electronic energy bands are not taken into account. Tak- ing energy level degeneracy as a continuous function of density, we have considered the pressure ionization effects for highly dense matter. Results for ^(13)Al atom are shown.展开更多
The atmospheric pressure chemical ionization/time of flight mass spectrometry (APCI/TOF MS) was applied to determine the mass of five α allenic alcohols via their protonated molecular ions using positive ion ...The atmospheric pressure chemical ionization/time of flight mass spectrometry (APCI/TOF MS) was applied to determine the mass of five α allenic alcohols via their protonated molecular ions using positive ion mode. Polyethylene glycol (PEG) was used as the internal reference. All results were obtained under the resolution of about 5000 FWHM (full width at the half maximum). Solvent effects were studied and the satisfied results were obtained in acetonitrile. Compared with the theoretical values, all absolute errors were less than 1.0 mmu. The effects of nozzle potential, push pulse potential, pull pulse potential, pull bias potential and acquisition rate on exact mass determination were also discussed. APCI/TOF MS is proven to be a very sensitive analytical technique and an alternative ionization mode in analyzing thermally labile compounds with relatively weak polarity, such as α allenic alcohol.展开更多
文摘The energy response calibration of the commonly used high pressure ionization chamber is very difficult to obtain when the gamma-ray energy is more than 3 MeV. In order to get the calibration of the higher part of the high pressure ionization chamber, we use the Fluka Monte Carlo program to perform the energy response in both the spherical and the cylindrical high pressure ionization chamber which are full of argon gas. The results compared with prior study when the gamma-ray energy is less than 1.25 MeV. Our result of Monte Carlo calculation shows agreement with those obtained by measurement within the uncertainty of the respective methods. The calculation of this study is significant for the high pressure ionization chamber to measure the high energy gamma-ray.
文摘Within the approximations of spherical lattice cell, central-field, and relativistic Fermi statis- tics, an algorithm with average atom model is presented to calculate the electronic energy levels and equation of state for hot and dense matter at arbitrary densities and temperatures. Choosing Zink's analytical potential as initial potential, we have solved the Dirac-Slater equation which satisfies the Weigner-Seitz boundary condition. The electronic energy bands are not taken into account. Tak- ing energy level degeneracy as a continuous function of density, we have considered the pressure ionization effects for highly dense matter. Results for ^(13)Al atom are shown.
基金theNationalNaturalScienceFoundationofChina (No .2 0 175 0 3 4)
文摘The atmospheric pressure chemical ionization/time of flight mass spectrometry (APCI/TOF MS) was applied to determine the mass of five α allenic alcohols via their protonated molecular ions using positive ion mode. Polyethylene glycol (PEG) was used as the internal reference. All results were obtained under the resolution of about 5000 FWHM (full width at the half maximum). Solvent effects were studied and the satisfied results were obtained in acetonitrile. Compared with the theoretical values, all absolute errors were less than 1.0 mmu. The effects of nozzle potential, push pulse potential, pull pulse potential, pull bias potential and acquisition rate on exact mass determination were also discussed. APCI/TOF MS is proven to be a very sensitive analytical technique and an alternative ionization mode in analyzing thermally labile compounds with relatively weak polarity, such as α allenic alcohol.
