Pervoskite-type oxides LaFe_ 1-yCu_yO_3 was prepared by citrate method. Using a fluorescent Hg lamp as irradiator, the degradation experiments of acid red 3B were carried out in the suspension system of LaFe_ 1-yCu_yO...Pervoskite-type oxides LaFe_ 1-yCu_yO_3 was prepared by citrate method. Using a fluorescent Hg lamp as irradiator, the degradation experiments of acid red 3B were carried out in the suspension system of LaFe_ 1-yCu_yO_3. The results show that the doped oxides LaFe_ 1-yCu_yO_3 have good photocatalytic oxidation property. With the study of positron annihilation, its photocatalytic activity is mainly related with defect structures resulted by doping.展开更多
The NiAl phase prepared by pack cementation （PC） on a nickel base superalloy was investigated by X-ray photoelectron spectroscopy （XPS） and positron annihilation technique （PAT）. The focus was on the effect of t...The NiAl phase prepared by pack cementation （PC） on a nickel base superalloy was investigated by X-ray photoelectron spectroscopy （XPS） and positron annihilation technique （PAT）. The focus was on the effect of the solid solution of the alloying element from substrate on the binding energy of Ni （Al） 2p peaks and vacancy concentration of the NiAI phase formed in a superalloy. The results showed that the binding energy of Ni 2p peak of the NiAI phase grown in a superalloy was shifted by up to 0.55 eV at the temperature from 850 to 1050℃ towards higher energies and the binding energy of Al 2p peak by up to 1.09 eV in comparison with the NiAl phase formed in pure Ni. The positron lifetimes obtained from the NiAl phase formed in a superalloy were found to be markedly lower than the theoretical values, indicating the decrease in vacancy concentration. The variation of binding energies and vacancy concentration are possibly due to the solid solution of the alloying atoms from the substrate into the NiAI lattice.展开更多
Based on experimental data of positron annihilation technology, electrolyticdissolution technique, electron back-scattered pattern, etc. and by analysis the strengtheningfactors, the strengthening mechanism of ultra-t...Based on experimental data of positron annihilation technology, electrolyticdissolution technique, electron back-scattered pattern, etc. and by analysis the strengtheningfactors, the strengthening mechanism of ultra-thin hot strip of low carbon steel produced by CSP(Compact Strip Production) technique was investigated. The value of each strengthening mechanism andits contribution percentage to yield strength were achieved. The results show that refinementstrengthening is the predominant strengthening mode; precipitation strengthening and dislocationstrengthening are second to it, their contributions to yield strength are almost equal.展开更多
文摘Pervoskite-type oxides LaFe_ 1-yCu_yO_3 was prepared by citrate method. Using a fluorescent Hg lamp as irradiator, the degradation experiments of acid red 3B were carried out in the suspension system of LaFe_ 1-yCu_yO_3. The results show that the doped oxides LaFe_ 1-yCu_yO_3 have good photocatalytic oxidation property. With the study of positron annihilation, its photocatalytic activity is mainly related with defect structures resulted by doping.
基金Financial support from the National Natural Science Foundation of China under grant Nos. 50501024 and 50671102 is gratefully acknowledged.
文摘The NiAl phase prepared by pack cementation （PC） on a nickel base superalloy was investigated by X-ray photoelectron spectroscopy （XPS） and positron annihilation technique （PAT）. The focus was on the effect of the solid solution of the alloying element from substrate on the binding energy of Ni （Al） 2p peaks and vacancy concentration of the NiAI phase formed in a superalloy. The results showed that the binding energy of Ni 2p peak of the NiAI phase grown in a superalloy was shifted by up to 0.55 eV at the temperature from 850 to 1050℃ towards higher energies and the binding energy of Al 2p peak by up to 1.09 eV in comparison with the NiAl phase formed in pure Ni. The positron lifetimes obtained from the NiAl phase formed in a superalloy were found to be markedly lower than the theoretical values, indicating the decrease in vacancy concentration. The variation of binding energies and vacancy concentration are possibly due to the solid solution of the alloying atoms from the substrate into the NiAI lattice.
基金This work was financially supported by the state foundation for key projects: Fundamental Research on New Generation of Steels (No: G1998061500).
文摘Based on experimental data of positron annihilation technology, electrolyticdissolution technique, electron back-scattered pattern, etc. and by analysis the strengtheningfactors, the strengthening mechanism of ultra-thin hot strip of low carbon steel produced by CSP(Compact Strip Production) technique was investigated. The value of each strengthening mechanism andits contribution percentage to yield strength were achieved. The results show that refinementstrengthening is the predominant strengthening mode; precipitation strengthening and dislocationstrengthening are second to it, their contributions to yield strength are almost equal.
