Photolysis studies on formic acid （HCOOH） and formate ion （HCOO-） in presence of TiO2, a photocatalyst, as suspension in water were carried out separately using 350 nm ultraviolet light. The products, such as H2, ...Photolysis studies on formic acid （HCOOH） and formate ion （HCOO-） in presence of TiO2, a photocatalyst, as suspension in water were carried out separately using 350 nm ultraviolet light. The products, such as H2, CO, CO2 and CH4, generated during the experiments were monitored with varying the ambient, light exposure time, and the concentration of HCOOH/HCOO-. The yields of CO in all these systems increased with light exposure time. In aerated systems, CO yields were higher in contrast to the deoxygenated （Ar-purged） systems under identical conditions. It is proposed apparently that the formation of CO is taking place during the chemical reduction of in-situ generated CO2, a photo-mineralized product of HCOOH/HCOO-, but not through the direct photodecomposition or photodehydration （CO＋H2O） of solute molecules. The rates of CO formation during 1.3 M HCOOH photolysis in presence of TiO2 photocatalyst were evaluated to be 0.21 and 0.13 μl/min in aerated and Ar-purged systems, respectively. As compared with HCOOH systems, the CO yields are lower when 0.2 M HCOONa was exposed to light under identical conditions. The CO growth rates were evaluated to be 0.07 and 0.046 μl/min^-1 for aerated and deoxygenated HCOONa systems, respectively; moreover, the trend is quite similar to that of the HCOOH system. Under these conditions, the emission of H2 was also observed, and its yield was significantly higher in Ar-purged system as compared with the CO yields. However, in aerated system, the yields of these products were just opposite. The formation of low yield of methane was observed during photolysis of HCOOH/HCOO ions. In CO2 ambient, the yields of CO and H2 varied drastically with time.展开更多
Based on the newest experimentally extracted nuclear density distributions for double-magic nucleus208Pb(Tarbert et al. in Phys Rev Lett 112:242502, 2014),the sensitivity of α-decay half-life to nuclear skin thicknes...Based on the newest experimentally extracted nuclear density distributions for double-magic nucleus208Pb(Tarbert et al. in Phys Rev Lett 112:242502, 2014),the sensitivity of α-decay half-life to nuclear skin thickness is explored in the vicinity of the shell closure region around208 Pb, i.e., isotopes of Z ? 82 and isotones of N ? 126.With the two-parameter Fermi(2PF) density distributions and an analytically derived formula, the α-decay half-life is found to be closely related to the magnitude of nuclear skin thickness. For a decays to the Z ? 82 isotopes, the α-decay half-life is found to decrease with the increasing neutron skin thickness, while the opposite behavior is found for a decays to the N ? 126 isotones. Therefore, it could be a possible way to extract the nuclear skin thickness from measured α-decay half-lives.展开更多
A combined plasma photolysis （CPP） reactor that utilized the dielectric barrier discharge （DBD） plasma together with DBD-driven KrI^＊ excimer ultraviolet emission was applied to the decomposition of H2S gas. The ...A combined plasma photolysis （CPP） reactor that utilized the dielectric barrier discharge （DBD） plasma together with DBD-driven KrI^＊ excimer ultraviolet emission was applied to the decomposition of H2S gas. The effects of applied voltage, input current, gas flow velocity, original concentration as well as the ratio of Kr/I2 mixture on H2S removal efficiency were investigated. Gas streams containing H2S were separately treated with single DBD and CPP reactor under the same conditions. In comparison to DBD, CPP could greatly enhance the H2S removal efficiency at the same applied voltage, inlet gas concentration and gas flow velocity. In addition, the reaction mechanism was also discussed in this paper.展开更多
The neutrons have been captured by Erbium nuclei which were received by using clinical electron linear accelerator. In this experiment, the possibility of the neutron capture process has been observed because of emitt...The neutrons have been captured by Erbium nuclei which were received by using clinical electron linear accelerator. In this experiment, the possibility of the neutron capture process has been observed because of emitted neutrons appearing in the experimental area. In particular,neutron capture of ^(170)Er nucleus has been observed. After the neutron capture of ^(170)Er nucleus, the unstable ^(171)Er has been formed and decayed into the ^(171)Tm. By using this reaction path, some transition energies of ^(171)Tm obtained from the residual activity measurements and the half-life of ^(171)Er have been determined, and they are in agreement with adopted values in the literature.展开更多
Photoinduced chemical reactions of 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim][PF_6]) were studied by laser photolysis at a wavelength of 266 nm.Excited triplet state ~3[bmim]^+ was observed,radical cation...Photoinduced chemical reactions of 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim][PF_6]) were studied by laser photolysis at a wavelength of 266 nm.Excited triplet state ~3[bmim]^+ was observed,radical cation [bmim]^(2+) and neutral [bmim] radical via photoionization were also formed.Energy transfer from ~3[bmim]^+ toβ-carotene was confirmed.Oxidation via one electron transfer from TMPD to ~3[bmim]^+ was also observed and the rate constant was determined to be 1.2×10.5 L.mol^(-1).s^(-1).The reaction of [bmim][PF_6] with hydrated electron (e_(aq)) was confirmed by laser photolysis in aqueous solution.展开更多
Reaction of p-tert-oxocalix[4]arene in acetonitrile (CH3CN) by 308nm laser pulses was investigated to understand its mechanism as polymer stabilizer. Four main absorption bands were observed at 300nm, 400nm, 460nm and...Reaction of p-tert-oxocalix[4]arene in acetonitrile (CH3CN) by 308nm laser pulses was investigated to understand its mechanism as polymer stabilizer. Four main absorption bands were observed at 300nm, 400nm, 460nm and 540nm. The 300nm absorption was assigned to the absorption of phenoxy radical, and the 460nm and 540nm were triple state absorption. It was concluded that the relative stable phenoxy radical mediate was formed through intramolecular energy transition of carbonyl triplet after laser excitation in CH3CN. The formation mechanism of phenoxyl radical was quite different from that in cyclohexane (C6H12), which was cooperation of two-photon process and one-photon process.展开更多
文摘Photolysis studies on formic acid （HCOOH） and formate ion （HCOO-） in presence of TiO2, a photocatalyst, as suspension in water were carried out separately using 350 nm ultraviolet light. The products, such as H2, CO, CO2 and CH4, generated during the experiments were monitored with varying the ambient, light exposure time, and the concentration of HCOOH/HCOO-. The yields of CO in all these systems increased with light exposure time. In aerated systems, CO yields were higher in contrast to the deoxygenated （Ar-purged） systems under identical conditions. It is proposed apparently that the formation of CO is taking place during the chemical reduction of in-situ generated CO2, a photo-mineralized product of HCOOH/HCOO-, but not through the direct photodecomposition or photodehydration （CO＋H2O） of solute molecules. The rates of CO formation during 1.3 M HCOOH photolysis in presence of TiO2 photocatalyst were evaluated to be 0.21 and 0.13 μl/min in aerated and Ar-purged systems, respectively. As compared with HCOOH systems, the CO yields are lower when 0.2 M HCOONa was exposed to light under identical conditions. The CO growth rates were evaluated to be 0.07 and 0.046 μl/min^-1 for aerated and deoxygenated HCOONa systems, respectively; moreover, the trend is quite similar to that of the HCOOH system. Under these conditions, the emission of H2 was also observed, and its yield was significantly higher in Ar-purged system as compared with the CO yields. However, in aerated system, the yields of these products were just opposite. The formation of low yield of methane was observed during photolysis of HCOOH/HCOO ions. In CO2 ambient, the yields of CO and H2 varied drastically with time.
基金supported by the National Natural Science Foundation of China(Nos.11175085,11235001,11375086,and 11120101005)the 973 Program of China(No.2013CB834400)+1 种基金the Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)the Open Project Program of the State Key Laboratory of Theoretical Physics,Institute of Theoretical Physics,Chinese Academy of Sciences,China(No.Y5KF141CJ1)
文摘Based on the newest experimentally extracted nuclear density distributions for double-magic nucleus208Pb(Tarbert et al. in Phys Rev Lett 112:242502, 2014),the sensitivity of α-decay half-life to nuclear skin thickness is explored in the vicinity of the shell closure region around208 Pb, i.e., isotopes of Z ? 82 and isotones of N ? 126.With the two-parameter Fermi(2PF) density distributions and an analytically derived formula, the α-decay half-life is found to be closely related to the magnitude of nuclear skin thickness. For a decays to the Z ? 82 isotopes, the α-decay half-life is found to decrease with the increasing neutron skin thickness, while the opposite behavior is found for a decays to the N ? 126 isotones. Therefore, it could be a possible way to extract the nuclear skin thickness from measured α-decay half-lives.
基金supported by Natural Science Foundation of Shanghai (No.07ZR14004)
文摘A combined plasma photolysis （CPP） reactor that utilized the dielectric barrier discharge （DBD） plasma together with DBD-driven KrI^＊ excimer ultraviolet emission was applied to the decomposition of H2S gas. The effects of applied voltage, input current, gas flow velocity, original concentration as well as the ratio of Kr/I2 mixture on H2S removal efficiency were investigated. Gas streams containing H2S were separately treated with single DBD and CPP reactor under the same conditions. In comparison to DBD, CPP could greatly enhance the H2S removal efficiency at the same applied voltage, inlet gas concentration and gas flow velocity. In addition, the reaction mechanism was also discussed in this paper.
基金supported by the Sinop University Scientific Research Projects Coordination Unit.Project Number:FEF-1901-14-04,2014
文摘The neutrons have been captured by Erbium nuclei which were received by using clinical electron linear accelerator. In this experiment, the possibility of the neutron capture process has been observed because of emitted neutrons appearing in the experimental area. In particular,neutron capture of ^(170)Er nucleus has been observed. After the neutron capture of ^(170)Er nucleus, the unstable ^(171)Er has been formed and decayed into the ^(171)Tm. By using this reaction path, some transition energies of ^(171)Tm obtained from the residual activity measurements and the half-life of ^(171)Er have been determined, and they are in agreement with adopted values in the literature.
基金Supported by National Natural Science Foundation of China(20573130,20673137)
文摘Photoinduced chemical reactions of 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim][PF_6]) were studied by laser photolysis at a wavelength of 266 nm.Excited triplet state ~3[bmim]^+ was observed,radical cation [bmim]^(2+) and neutral [bmim] radical via photoionization were also formed.Energy transfer from ~3[bmim]^+ toβ-carotene was confirmed.Oxidation via one electron transfer from TMPD to ~3[bmim]^+ was also observed and the rate constant was determined to be 1.2×10.5 L.mol^(-1).s^(-1).The reaction of [bmim][PF_6] with hydrated electron (e_(aq)) was confirmed by laser photolysis in aqueous solution.
基金National Natural Science Foundation of China (No.29602005)Director’s Funds of CAEP (No.42105040407 and No.62601080311)
文摘Reaction of p-tert-oxocalix[4]arene in acetonitrile (CH3CN) by 308nm laser pulses was investigated to understand its mechanism as polymer stabilizer. Four main absorption bands were observed at 300nm, 400nm, 460nm and 540nm. The 300nm absorption was assigned to the absorption of phenoxy radical, and the 460nm and 540nm were triple state absorption. It was concluded that the relative stable phenoxy radical mediate was formed through intramolecular energy transition of carbonyl triplet after laser excitation in CH3CN. The formation mechanism of phenoxyl radical was quite different from that in cyclohexane (C6H12), which was cooperation of two-photon process and one-photon process.
