The multiphoton ionization dissociation of HFC 152a and HFC 134a under the irradiation of 355 nm and 266 nm was studied in this work. Their photolyzed products were analyzed by time of flight mass spectrum instrument....The multiphoton ionization dissociation of HFC 152a and HFC 134a under the irradiation of 355 nm and 266 nm was studied in this work. Their photolyzed products were analyzed by time of flight mass spectrum instrument. The photolyzed products of HFC 152a include H +( m/z =1), C +( m/z =12), CH + 3( m/z =15), C + 2( m/z =24), CF 2H +( m/z =51), and CF +( m/z =31), whereas there is no clear products for HFC 134a photolyzation. Further, the application prospects of HFC 152a and HFC 134a in refrigeration sector were also evaluated from the view point of environmental protection, synthesis conditions and usage performance. It is suggested that HFC 152a is a better alternative compared to HFC 134a in refrigeration sector.展开更多
Copper-sulfur cluster ions were produced by laser ablation on solid samples: (1) a mixture of copper and sulfur powder, (2) cuprous sulfide compound, (3)cupric suffide compound, respectively. Two main series of cluste...Copper-sulfur cluster ions were produced by laser ablation on solid samples: (1) a mixture of copper and sulfur powder, (2) cuprous sulfide compound, (3)cupric suffide compound, respectively. Two main series of cluster ions were found: (a)[Cu(Cu2S)n]+(n=0-22), (b) [(Cu2S)n]+(n=1-18). The main photodissociation channels of the cluster ions were neutral losses of Cu2S, Cu or CuS. It is obvious that the Cu2S unit plays an important role in the formation and structure of the Cu/S cluster ions, and farthermore, the mied d10 shell eletronic configuration of copper element might be critical to the characteristic of the cluster ions.展开更多
The ultrafast processes of tetra-phenyl-porphyrin(TPP), tetra-t-butyl-phthalocyanine(BuPc) and nitro-tri-t-butyl-phthalocyanine (NtBuPc) have been inves-tigated using the femtosecond time-resolved fluorescence depleti...The ultrafast processes of tetra-phenyl-porphyrin(TPP), tetra-t-butyl-phthalocyanine(BuPc) and nitro-tri-t-butyl-phthalocyanine (NtBuPc) have been inves-tigated using the femtosecond time-resolved fluorescence depletion method. A sharp peakof the fluorescence depletion with delay time has been observed both for TPP and BuPc.An ultrafast two-photon absorption process has been proposed to explain the sharp peakobserved. A long-lived fluorescence depletion has also been observed. It is causing by thestimulated-emission-pumping process produced by the intense probe laser pulses.展开更多
文摘The multiphoton ionization dissociation of HFC 152a and HFC 134a under the irradiation of 355 nm and 266 nm was studied in this work. Their photolyzed products were analyzed by time of flight mass spectrum instrument. The photolyzed products of HFC 152a include H +( m/z =1), C +( m/z =12), CH + 3( m/z =15), C + 2( m/z =24), CF 2H +( m/z =51), and CF +( m/z =31), whereas there is no clear products for HFC 134a photolyzation. Further, the application prospects of HFC 152a and HFC 134a in refrigeration sector were also evaluated from the view point of environmental protection, synthesis conditions and usage performance. It is suggested that HFC 152a is a better alternative compared to HFC 134a in refrigeration sector.
文摘Copper-sulfur cluster ions were produced by laser ablation on solid samples: (1) a mixture of copper and sulfur powder, (2) cuprous sulfide compound, (3)cupric suffide compound, respectively. Two main series of cluster ions were found: (a)[Cu(Cu2S)n]+(n=0-22), (b) [(Cu2S)n]+(n=1-18). The main photodissociation channels of the cluster ions were neutral losses of Cu2S, Cu or CuS. It is obvious that the Cu2S unit plays an important role in the formation and structure of the Cu/S cluster ions, and farthermore, the mied d10 shell eletronic configuration of copper element might be critical to the characteristic of the cluster ions.
文摘The ultrafast processes of tetra-phenyl-porphyrin(TPP), tetra-t-butyl-phthalocyanine(BuPc) and nitro-tri-t-butyl-phthalocyanine (NtBuPc) have been inves-tigated using the femtosecond time-resolved fluorescence depletion method. A sharp peakof the fluorescence depletion with delay time has been observed both for TPP and BuPc.An ultrafast two-photon absorption process has been proposed to explain the sharp peakobserved. A long-lived fluorescence depletion has also been observed. It is causing by thestimulated-emission-pumping process produced by the intense probe laser pulses.
