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VUV Photoionization Study of the Allyl Radical from Premixed Gasoline/Oxygen Flame 被引量:3
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作者 Rui Yang Bin Yang +9 位作者 Chao-qun Huang Li-xia Wei Jing Wang Xiao-bin Shan liu-si sheng Yun-wu Zhang Fei Qi Chun-de Yao Qi Li Qing Ji 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 北大核心 2006年第1期25-28,共4页
The allyl radical has been observed in a low-pressure premixed gasoline/oxygen/argon flame by using tunable vacuum ultraviolet photoionization mass spectrometry, The ionization potential of the allyl radical is derive... The allyl radical has been observed in a low-pressure premixed gasoline/oxygen/argon flame by using tunable vacuum ultraviolet photoionization mass spectrometry, The ionization potential of the allyl radical is derived to be (8.13 ±0.02) eV from photoionization efficiency curve, In addition, a high level ab initzo Gaussian-3 (G3) method was used to calculate the energies of tile radical and its cation. The calculated adiabatic ionization potential is 8.18 eV, which is in excellent agreement with the experimental value. The result is helpful for identifying the allyl radical formed from other flames and for understanding the mechanism of soot formation. 展开更多
关键词 Ally radical Photoionization efficiency curve FLAME
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Investigation of Vacuum Ultraviolet Photoionization of Methylcyclohexane in Energy Region of 9-15.5 eV 被引量:1
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作者 Hang Zhang Yan-bo Li +7 位作者 Long Zhu Jun Chen Ye-peng Yu Zhao-hui Li Xuan Lin Xiao-bin Shan Fu-yi Liu liu-si sheng 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2020年第3期296-302,I0002,共8页
Vacuum ultraviolet(VUV)photoionization and photodissociation of methylcyclohexane have been studied utilizing a reflectron time-of-flight mass spectrometer(RTOF-MS)with synchrotron radiation source.Photoionization eff... Vacuum ultraviolet(VUV)photoionization and photodissociation of methylcyclohexane have been studied utilizing a reflectron time-of-flight mass spectrometer(RTOF-MS)with synchrotron radiation source.Photoionization efficiency curves(PIEs)of molecule ion C7H14^+ and fragment ions C7H13^+,C6H11^+,C6H10+,C5H10^+,C5H9^+,C4H8^+,C4H7^+,and C3H5^+ were observed.The ionization energy of methylcyclohexane was measured to be(9.80±0.03)eV,and appearance energies of fragment ions were determined from the PIEs.Optimized structures of transitional states,intermediates and product ions were characterized at the B3LYP/6-31G(d)level and the energies were calculated using G3B3 method.Formation channels of dominating fragment ions were proposed.Intramolecular hydrogen migrations and carbon ring-opening were the foremost processes in fragmentation pathways of methylcyclohexane. 展开更多
关键词 METHYLCYCLOHEXANE Photoionization and photodissociation Synchrotron radiation source Reflectron time-of-flight mass spectrometer
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A reinvestigation of low molecular weight components in SOA produced by cyclohexene ozonolysis
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作者 Jun Chen Zhao-Hui Li +12 位作者 Ye-Peng Yu Xuan Lin Hang Zhang Yan-Bo Li Huan-Huan Wang Rui-Rui Sun Qing-Hui Meng Chao-Qun Huang Xiao-Bin Shan Fu-Yi Liu Chang-Jin Hu Wei-Jun Zhang liu-si sheng 《Nuclear Science and Techniques》 SCIE CAS CSCD 2018年第11期238-246,共9页
The ozonolysis of cyclohexene is an important model system for understanding the more complex reaction of O_3 with monoterpenes; however, many previous studies have come to qualitatively different conclusions about th... The ozonolysis of cyclohexene is an important model system for understanding the more complex reaction of O_3 with monoterpenes; however, many previous studies have come to qualitatively different conclusions about the composition of the secondary organic aerosol(SOA)formed in this system. In the present study, the composition of the SOA produced by cyclohexene ozonolysis in the absence of seed aerosols has been investigated online and off-line using synchrotron-based thermal desorption/tunable vacuum ultraviolet photoionization time-of-flight aerosol mass spectrometry(TD-VUV-TOF-PIAMS) in conjunction with a custom-built smog chamber. On the basis of the molecular ions observed by mass spectrometry at 11.5 e V, it was found that dicarboxylic acids, dialdehydes, and cyclic anhydrides are the predominant low molecular weight components in the particle phase. The results also indicated that TD-VUV-TOF-PIAMS coupled with filter sampling is a potentially useful tool for the investigation of SOA composition both in the field and in the laboratory. 展开更多
关键词 CYCLOHEXENE OZONOLYSIS SOA SMOG CHAMBER Aerosol mass SPECTROMETRY
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Design and testing of an internal hot-cathode-type PIG ion source for superconducting cyclotron
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作者 Shi-Wen Xu Yun-Tao Song +6 位作者 Gen Chen Yu-Qian Chen liu-si sheng Man-Man Xu Oleg Karamyshev Galina Karamysheva Grigori Shirkov 《Nuclear Science and Techniques》 SCIE CAS CSCD 2019年第6期10-15,共6页
The superconducting cyclotron SC200 is intended to generate a 200 MeV, 400 nA proton beam for future particle therapy. The internal hot-cathode-type Penning ionization gauge (PIG) ion source for the SC200 is designed ... The superconducting cyclotron SC200 is intended to generate a 200 MeV, 400 nA proton beam for future particle therapy. The internal hot-cathode-type Penning ionization gauge (PIG) ion source for the SC200 is designed for the generation of hydrogen ions. A brief description of the design of ion source and test bench, which are used in SC200, is given in this paper. The ion source has been verified on the test bench, and the results indicated that the designed ion source meets the expected requirements. The lifetime of the filament exceeded 100 h in the test. In addition, the extraction voltage and the gas flow that influence the extracted ion current intensity have been tested in the experiment. 展开更多
关键词 CYCLOTRONS Ion source Test BENCH Simulation
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Photoionization and Dissociation Study of 2-Methyl-2-propen-1-ol:Experimental and Theoretical Insights
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作者 Ye-peng Yu Zhao-hui Li +9 位作者 Xuan Lin Jun Chen Hang Zhang Yan-bo Li Huang-huang Wang Rui-rui Sun Qing-hui Meng Xiao-bin Shan Fu-yi Liu liu-si sheng 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2019年第3期306-312,I0001,共8页
The photoionization and dissociation of 2-methyl-2-propen-1-ol(MPO)have been investigated by using molecular beam experimental apparatus with tunable vacuum ultraviolet synchrotron radiation in the photon energy regio... The photoionization and dissociation of 2-methyl-2-propen-1-ol(MPO)have been investigated by using molecular beam experimental apparatus with tunable vacuum ultraviolet synchrotron radiation in the photon energy region of 8.0-15.5 eV.The photoionization efficiency(PIE)curves for molecule ion and fragment ions:C4H8O^+,C4H7O^+,C3H5O^+,C4H7^+,C4H6^+,C4H5^+,C2H4O^+,C2H3O+,C3H6^+,C3H5^+,C3H3^+,CH3O^+,CHO^+have been measured,and the ionization energy(IE)and the appearance energies(AEs)of the fragment ions have been obtained.The stable species and the first order saddle points have been calculated on the CCSD(T)/cc-pvTZ//B3LYP/6-31+G(d,p)level.With combination of theoretical and experimental results,the dissociative photoionization pathways of 2-methyl-2-propen-1-ol are proposed.Hydrogen migrations within the molecule are the dominant processes in most of the fragmentation pathways of MPO. 展开更多
关键词 2-Methyl-2-propen-1-ol Synchrotron radiation PHOTOIONIZATION Vacuum ultraviolet Mass spectrometry
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Experimental and Theoretical Study on Dissociative Photoionization of Cyclopentanone
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作者 Zhao-hui Li Ye-peng Yu +9 位作者 Xuan Lin Jun Chen Hang Zhang Yan-bo Li Huan-huan Wang Qing-hui Meng Rui-rui Sun Xiao-bin Shan Fu-yi Liu liu-si sheng 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2018年第5期619-625,735,共8页
The dissociative photoionization of cyclopentanone was investigated by means of a reflectron time-of-flight mass spectrometer(RTOF-MS)with tunable vacuum ultraviolet synchrotron radiation in the photon energy range of... The dissociative photoionization of cyclopentanone was investigated by means of a reflectron time-of-flight mass spectrometer(RTOF-MS)with tunable vacuum ultraviolet synchrotron radiation in the photon energy range of 9.0~15.5 eV.The photoionization efficiency(PIE)curves for molecular ion and fragment ions were measured.The ionization energy of cyclopentanone was determined to be 9.230.03 eV.Fragment ions from the dissociative photoionization of cyclopentanone were identified as C5H7O+,C4H5O+,C4H8+/C3H4O+,C3H3O+,C4H6+,C2H4O+,C3H6+,C3H5+,C3H4+,C3H3+,C2H5+and C2H4+.With the aid of the ab initio calculations at theωB97X-D/6-31+G(d,p)level of theory,the dissociative mechanisms of C5H8O+are proposed.Ring opening and hydrogen migrations are the predominant processes in most of the fragmentation pathways of cyclopentanone. 展开更多
关键词 CYCLOPENTANONE Synchrotron radiation Photoionization and dissociation ab initio calculations
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