Be handicapped by the method of analysis and samples of plaster ground,in the article " Research on Efflorescence of Wall Paintings in the Mogao Grattoes of Dunhuang(I)" we only found Nacl. Now according wit...Be handicapped by the method of analysis and samples of plaster ground,in the article " Research on Efflorescence of Wall Paintings in the Mogao Grattoes of Dunhuang(I)" we only found Nacl. Now according with the other’s research achievements, weknow that there may be another kind of solvable salt Na2SO4· 10H2O in plaster ground.On the basis of XRD, we find that the samples are taken in different places, the contentof NaCl is different, that is to say, the degree of efflorescence of wall paintings has relation to the NaCl content of plaster ground. Through the analysis of XRF, we have foundthe solvable salt Na2SO4· 10H2O stored in the samples of plaster ground. At the sametime, we have made a quantitative analysis of these two kinds of salts which induced efflorescence of Dunhuang murals by the XRF.展开更多
Progres in ion beam analysis at Fudan University in the recent years is briefly reviewed. Presented as examples of the research activities performed in this field are the following projects: (1) Nuclear potential reso...Progres in ion beam analysis at Fudan University in the recent years is briefly reviewed. Presented as examples of the research activities performed in this field are the following projects: (1) Nuclear potential resonance scattering of 6.25 MeV and 4.25 MeV helium ions for simultaneous compositional analysis of carbon and oxygen in a Mylar, a SnInO, and some other film samples: (2) Determination of stoichiometry of a high-temperature superconducting Y-Ba-Cu-O sample by backscattering of 8.8 MeV helium ions; (3) Backscattering and channeling analysis of multilayered structures periodically consisting of layers of pure Si and alternate layers of Ge and Si, grown on (100) Si substrates by molecular beam epitaxy: (4) Studies of surface structure of Al(100) by the use of MeV ions backscattering and channeling surface peak: and (5) MeV ion microbeam analysis and the use of PIXE method in DNA study. etc.展开更多
An experimental apparatus for studies of MeV ion beam modification of materials has been established on a 3 MV tandem accelerator at Fudan university. A system of X-Y electrostatic scanning implantation of MeV heavy i...An experimental apparatus for studies of MeV ion beam modification of materials has been established on a 3 MV tandem accelerator at Fudan university. A system of X-Y electrostatic scanning implantation of MeV heavy ions and in situ Rutherford. backscattering analysis was included in it. The uniformity of scanning implantation was checked by the RBS measurement of a Si wafer implanted with 1 MeV Au ions. MeV ion beam mixing of Au/Si, Au/Ge and Ag/Si systems was preliminarily studied. The samples were irradiated by certain fluences of 1 MeV Ag ions at room temperature. The mixed layers were analyzed in situ using the glancing RBS technique with 2 MeV 4He+ ions. For Au/Si system, a uniformly mixed layer with a defined composition is obtained, and the intermixing is much less for Ag/Si system than for Au/Si system.展开更多
Atomic spectra of singly ionized neodymium have been measured by collinear fast-ion-beam laser spectroscopy.The resonant spectra in the lines of 568.9,570.8,572.7,and 574.1 nm in NdH were obtained and the optical shif...Atomic spectra of singly ionized neodymium have been measured by collinear fast-ion-beam laser spectroscopy.The resonant spectra in the lines of 568.9,570.8,572.7,and 574.1 nm in NdH were obtained and the optical shifts were determined.We obtained the optical shifts of all the five even isotopes(142-150)in Nd IL The accuracy of our results was improved by one order of magnitude compared with other published results.展开更多
The collinear fast ion beam-laser spectroscopy has been used to measure the radiative lifetime of the(23587)°_(9/2) level of the rare earth ions NdII.The measurement was carried out by the interaction between the...The collinear fast ion beam-laser spectroscopy has been used to measure the radiative lifetime of the(23587)°_(9/2) level of the rare earth ions NdII.The measurement was carried out by the interaction between the SOkeV Ndll ion beam and tunable collinear dye laser which resonantly ezcited a metastable level to the(23537)°_(9/2) level,and by the observation of its time-resolved decay downstream.The lifetime value obtained from a fit program was 27.6±0.9ns.The result may provide a possibility of determining the unknown configuration of the(23537)°_(9/2) level.展开更多
文摘Be handicapped by the method of analysis and samples of plaster ground,in the article " Research on Efflorescence of Wall Paintings in the Mogao Grattoes of Dunhuang(I)" we only found Nacl. Now according with the other’s research achievements, weknow that there may be another kind of solvable salt Na2SO4· 10H2O in plaster ground.On the basis of XRD, we find that the samples are taken in different places, the contentof NaCl is different, that is to say, the degree of efflorescence of wall paintings has relation to the NaCl content of plaster ground. Through the analysis of XRF, we have foundthe solvable salt Na2SO4· 10H2O stored in the samples of plaster ground. At the sametime, we have made a quantitative analysis of these two kinds of salts which induced efflorescence of Dunhuang murals by the XRF.
文摘Progres in ion beam analysis at Fudan University in the recent years is briefly reviewed. Presented as examples of the research activities performed in this field are the following projects: (1) Nuclear potential resonance scattering of 6.25 MeV and 4.25 MeV helium ions for simultaneous compositional analysis of carbon and oxygen in a Mylar, a SnInO, and some other film samples: (2) Determination of stoichiometry of a high-temperature superconducting Y-Ba-Cu-O sample by backscattering of 8.8 MeV helium ions; (3) Backscattering and channeling analysis of multilayered structures periodically consisting of layers of pure Si and alternate layers of Ge and Si, grown on (100) Si substrates by molecular beam epitaxy: (4) Studies of surface structure of Al(100) by the use of MeV ions backscattering and channeling surface peak: and (5) MeV ion microbeam analysis and the use of PIXE method in DNA study. etc.
基金The Project Supported by National Natural Science Foundation of China
文摘An experimental apparatus for studies of MeV ion beam modification of materials has been established on a 3 MV tandem accelerator at Fudan university. A system of X-Y electrostatic scanning implantation of MeV heavy ions and in situ Rutherford. backscattering analysis was included in it. The uniformity of scanning implantation was checked by the RBS measurement of a Si wafer implanted with 1 MeV Au ions. MeV ion beam mixing of Au/Si, Au/Ge and Ag/Si systems was preliminarily studied. The samples were irradiated by certain fluences of 1 MeV Ag ions at room temperature. The mixed layers were analyzed in situ using the glancing RBS technique with 2 MeV 4He+ ions. For Au/Si system, a uniformly mixed layer with a defined composition is obtained, and the intermixing is much less for Ag/Si system than for Au/Si system.
基金Supported by the National Natural Science Foundation of China under Grant No.19774016.
文摘Atomic spectra of singly ionized neodymium have been measured by collinear fast-ion-beam laser spectroscopy.The resonant spectra in the lines of 568.9,570.8,572.7,and 574.1 nm in NdH were obtained and the optical shifts were determined.We obtained the optical shifts of all the five even isotopes(142-150)in Nd IL The accuracy of our results was improved by one order of magnitude compared with other published results.
基金Supported by The Chinese National Science Foundation for Doctoral Research。
文摘The collinear fast ion beam-laser spectroscopy has been used to measure the radiative lifetime of the(23587)°_(9/2) level of the rare earth ions NdII.The measurement was carried out by the interaction between the SOkeV Ndll ion beam and tunable collinear dye laser which resonantly ezcited a metastable level to the(23537)°_(9/2) level,and by the observation of its time-resolved decay downstream.The lifetime value obtained from a fit program was 27.6±0.9ns.The result may provide a possibility of determining the unknown configuration of the(23537)°_(9/2) level.
