Thiamphenicol(THA) and florfenicol(FLO) aqueous solutions were irradiated to different doses by 1 MeV electron beams,and redox reactions of THA/FLO and radicals of OH,e_(eq)^- and ~·H were investigated under vari...Thiamphenicol(THA) and florfenicol(FLO) aqueous solutions were irradiated to different doses by 1 MeV electron beams,and redox reactions of THA/FLO and radicals of OH,e_(eq)^- and ~·H were investigated under various conditions.The results showed that at 8 kGy,the decomposition rate of THA and FLO was 97.2%and 98.5%, respectively.Quantitative and qualitative analysis indicated that OH played a key role in E-beam degradation of the THA and FLO in aqueous solutions,and e_(eq)^- and ~·H radicals could initiate the degradation,too.Seven primary products of the THA and FLO degradation were identified.These indicate that E-beam radiation is an effective method to reduce THA and FLO in aqueous solutions.展开更多
To investigate the influence of radiolysis on kinetics and factors of dimethyl phthalate(DMP),the aqueous DMP solution is degraded by 1.8 MeV E-beam,following pseudo-first-order kinetics.The rate constant of DMP degra...To investigate the influence of radiolysis on kinetics and factors of dimethyl phthalate(DMP),the aqueous DMP solution is degraded by 1.8 MeV E-beam,following pseudo-first-order kinetics.The rate constant of DMP degradation decreased exponentially with increasing initial DMP concentration.The DMP is favorably degraded by radical scavengers under its low concentration and alkaline condition.At high doses,the DMP is attacked by eaq-and ·OH,producing monomethyl phthalate,phthalate acid,and a series of aliphatic carboxylic acids,which are completelymineralized into H2O and CO2.展开更多
E-beam degradation of bisphenol A(BPA) was carried out,under reductive condition of ethanol-water solution and oxidative condition of acetonitrile-water solution.The degradation efficiency is higher in oxidative condi...E-beam degradation of bisphenol A(BPA) was carried out,under reductive condition of ethanol-water solution and oxidative condition of acetonitrile-water solution.The degradation efficiency is higher in oxidative condition than that in reductive condition,and increases with the dose but decreased with increasing initial concentration.The BPA radiolysis follows the pseudo-first-order kinetics.Adding H_2O_2,or neutral condition,does not benefit BPA degradation in oxidative conditions.Pulsed radiolysis was used to investigate mechanism of the BPA radiolysis.The rate constant for BPA reaction with OH(1.85×10^(10) L·mor^(-1)·s^(-1)) is about an order of magnitude higher than that with e_(aq)^-(1.80×l0~9 L·mor^(-1)·s^(-1)).The degradation products were analyzed by ion chromatograph.Smaller molecules such as formic acid and acetic acid were detected,indicating that ^-OH attacks the BPA molecule.The work is of significance for the practical E-beam treatment of waste water containing BPA.展开更多
We fabricate high-quality A1/A1Ox/A1 junctions using improved bridge and bridge-free techniques at 30-keV e-beam voltage,in which the length of undercut and the size of junction can be well controlled by the pre-expos...We fabricate high-quality A1/A1Ox/A1 junctions using improved bridge and bridge-free techniques at 30-keV e-beam voltage,in which the length of undercut and the size of junction can be well controlled by the pre-exposure technique.The dose window is 5 times as large as that used in the usual Dolan bridge technique,making this technique much more robust.Similar results,comparable with those achieved using a 100-keV e-beam writer,are obtained,which indicate that the 30-keV e-beam writer could be an economic choice for the superconducting qubit fabrication.展开更多
The critical parameters of electron beam to cure the epoxy resin E-44 were studied. The initiating efficiency of every photoinitiator increases with the increase of the absorbed dose. Diphenyl iodonium hexafluoroantim...The critical parameters of electron beam to cure the epoxy resin E-44 were studied. The initiating efficiency of every photoinitiator increases with the increase of the absorbed dose. Diphenyl iodonium hexafluoroantimonate being the photoinitiator has a higher initiating efficiency, whose optimal quantity is 3%. The curing degree of the system is improved continuously with the increments of the photoinitiator content when the absorbed dose and the dose rate are fixed. The curing degree increases with raising dose rate obviously when the absorbed dose are fixed.展开更多
Cu_2O nanocrystals were synthesized by irradiating an aqueous solution of CuSO_4·5H_2O(1.25g),polyvinyl alcohol(PVA,0.8 g),and isopropanol(3.1 mL).The products were characterized by powder XRD,TEM and SEM. Methyl...Cu_2O nanocrystals were synthesized by irradiating an aqueous solution of CuSO_4·5H_2O(1.25g),polyvinyl alcohol(PVA,0.8 g),and isopropanol(3.1 mL).The products were characterized by powder XRD,TEM and SEM. Methyl orange degradation under visible light using the Cu_2O nanocrystals as catalyst was studied by UV-Vis absorption method.The results show that the products are nanocrystals of pure Cu_2O.Morphology and size of the nanoparticles are affected by the irradiation dose and pH value of the initial solution.Octahedral Cu_2O nanocrystals of 116 nm in size can be obtained at the initial pH of 8.0 and 280-kGy irradiation.The nanocrystals have excellent catalytic activity for photodegradation of the methyl orange solution bubbled at the air-flow rate of 750 mL·min^(-1),due to the large {111} facets of octahedral Cu_2O particles.展开更多
CdSe quantum dots (QDs) were prepared at room temperature by E-beam irradiation of the solution, using ethylene diamine tetraacetic acid as stabilizer. Silica-coated CdSe QDs were made in water-in-oil microemulsion, w...CdSe quantum dots (QDs) were prepared at room temperature by E-beam irradiation of the solution, using ethylene diamine tetraacetic acid as stabilizer. Silica-coated CdSe QDs were made in water-in-oil microemulsion, while amino groups were introduced synchronously onto the nanoparticles by copolymerization of 3-aminopropyl- trimethoxysilane and tetraethyl orthosilicate. The results of TEM imaging, fluorescent spectroscopy and photostability tests show that the QDs are of uniform spherical size (200±8 nm), monodispersity, and high fluorescence and photostability.展开更多
Polybrominated diphenyl ethers (PBDEs) spread widely in the environment are mainly removed by photochemical and anaerobic microbial degradation. In this paper, the decomposition of 4-bromodiphenyl ether (BDE -3), the ...Polybrominated diphenyl ethers (PBDEs) spread widely in the environment are mainly removed by photochemical and anaerobic microbial degradation. In this paper, the decomposition of 4-bromodiphenyl ether (BDE -3), the PBDEs homologues, is investigated by electron beam irradiation of its ethanol/water solution (reduction system) and acetonitrile/water solution (oxidation system). The radiolytic products were determined by GC coupled with electron capture detector, and the reaction rate constant of esol– in the reduction system was measured at 2.7×1010 L·mol–1·s–1 by pulsed radiolysis. The results show that the BDE-3 concentration affects strongly the decomposition ratio in the alkali solution, and the reduction system has a higher BDE-3 decomposition rate than the oxidation system. This indicates that the BDE-3 was reduced by effectively capturing esol– in radiolytic process.展开更多
This paper describes the industrial electron accelerators of the ILU type and their usage for sterilization.The ILU machines produced by Budker Institute of Nuclear Physics have energy range of 0.8-10 MeV and beam pow...This paper describes the industrial electron accelerators of the ILU type and their usage for sterilization.The ILU machines produced by Budker Institute of Nuclear Physics have energy range of 0.8-10 MeV and beam power up to 100 kW,and they are working in industries all over the world.The ILU-10 and ILU-14 machines are described as well as the industrial sterilization facility based on ILU-6,ILU-10 and ILU-14 machines.展开更多
基金Supported by National Natural Science Foundation of China(No.40973073,40830744)Project of Leading Disciplinary Studies in Shanghai(No.S30109)+1 种基金National Key Technology R&D Program in the 11th Five-year-plan of China(No.2008BAC32B03,2009BAA24B04)Municipal Natural Science Foundation of Shanghai(No.09ZR1411300)
文摘Thiamphenicol(THA) and florfenicol(FLO) aqueous solutions were irradiated to different doses by 1 MeV electron beams,and redox reactions of THA/FLO and radicals of OH,e_(eq)^- and ~·H were investigated under various conditions.The results showed that at 8 kGy,the decomposition rate of THA and FLO was 97.2%and 98.5%, respectively.Quantitative and qualitative analysis indicated that OH played a key role in E-beam degradation of the THA and FLO in aqueous solutions,and e_(eq)^- and ~·H radicals could initiate the degradation,too.Seven primary products of the THA and FLO degradation were identified.These indicate that E-beam radiation is an effective method to reduce THA and FLO in aqueous solutions.
基金Supported by National Natural Science Foundation of China (No. 40830744 and 40973073)National Key Technology R&D Program in the 11th Five-year Plan of China (No.2008BAC32B03)+2 种基金Shanghai Leading Academic Discipline Project (No.S30109)Science and Technology Commission of Shanghai Municipality (No. 09ZR1411300A.10-0111-07-003)
文摘To investigate the influence of radiolysis on kinetics and factors of dimethyl phthalate(DMP),the aqueous DMP solution is degraded by 1.8 MeV E-beam,following pseudo-first-order kinetics.The rate constant of DMP degradation decreased exponentially with increasing initial DMP concentration.The DMP is favorably degraded by radical scavengers under its low concentration and alkaline condition.At high doses,the DMP is attacked by eaq-and ·OH,producing monomethyl phthalate,phthalate acid,and a series of aliphatic carboxylic acids,which are completelymineralized into H2O and CO2.
基金Supported byNational Natural Science Foundation ofChina(Nos 40973073,40830744,11025526,11175112)National Key TechnologyR&D Programinthe 11th Five-year Plan of China(No.2009BAA24B04)Shanghai Leading Academic Discipline Project(No.S30109)
文摘E-beam degradation of bisphenol A(BPA) was carried out,under reductive condition of ethanol-water solution and oxidative condition of acetonitrile-water solution.The degradation efficiency is higher in oxidative condition than that in reductive condition,and increases with the dose but decreased with increasing initial concentration.The BPA radiolysis follows the pseudo-first-order kinetics.Adding H_2O_2,or neutral condition,does not benefit BPA degradation in oxidative conditions.Pulsed radiolysis was used to investigate mechanism of the BPA radiolysis.The rate constant for BPA reaction with OH(1.85×10^(10) L·mor^(-1)·s^(-1)) is about an order of magnitude higher than that with e_(aq)^-(1.80×l0~9 L·mor^(-1)·s^(-1)).The degradation products were analyzed by ion chromatograph.Smaller molecules such as formic acid and acetic acid were detected,indicating that ^-OH attacks the BPA molecule.The work is of significance for the practical E-beam treatment of waste water containing BPA.
基金supported by the National Natural Science Foundation of China(Grant Nos.91321310,11274156,11474152,11474153,61521001,and 11504165)the State Key Basic Research Program of China(Grant Nos.2011CB922104 and 2011CBA00205)
文摘We fabricate high-quality A1/A1Ox/A1 junctions using improved bridge and bridge-free techniques at 30-keV e-beam voltage,in which the length of undercut and the size of junction can be well controlled by the pre-exposure technique.The dose window is 5 times as large as that used in the usual Dolan bridge technique,making this technique much more robust.Similar results,comparable with those achieved using a 100-keV e-beam writer,are obtained,which indicate that the 30-keV e-beam writer could be an economic choice for the superconducting qubit fabrication.
文摘The critical parameters of electron beam to cure the epoxy resin E-44 were studied. The initiating efficiency of every photoinitiator increases with the increase of the absorbed dose. Diphenyl iodonium hexafluoroantimonate being the photoinitiator has a higher initiating efficiency, whose optimal quantity is 3%. The curing degree of the system is improved continuously with the increments of the photoinitiator content when the absorbed dose and the dose rate are fixed. The curing degree increases with raising dose rate obviously when the absorbed dose are fixed.
基金Supported by Shanghai Leading Academic Discipline Project(S30109)the Innovation Foundation of Shanghai University for Ph.D.candidates (SHUCX091033)
文摘Cu_2O nanocrystals were synthesized by irradiating an aqueous solution of CuSO_4·5H_2O(1.25g),polyvinyl alcohol(PVA,0.8 g),and isopropanol(3.1 mL).The products were characterized by powder XRD,TEM and SEM. Methyl orange degradation under visible light using the Cu_2O nanocrystals as catalyst was studied by UV-Vis absorption method.The results show that the products are nanocrystals of pure Cu_2O.Morphology and size of the nanoparticles are affected by the irradiation dose and pH value of the initial solution.Octahedral Cu_2O nanocrystals of 116 nm in size can be obtained at the initial pH of 8.0 and 280-kGy irradiation.The nanocrystals have excellent catalytic activity for photodegradation of the methyl orange solution bubbled at the air-flow rate of 750 mL·min^(-1),due to the large {111} facets of octahedral Cu_2O particles.
基金Supported by National Natural Science Foundation of China (No. 40830744)Shanghai Nano Program (No. 0752nm024)Graduate Student Innovation Fund of Shanghai University (No.SHUCX091034)
文摘CdSe quantum dots (QDs) were prepared at room temperature by E-beam irradiation of the solution, using ethylene diamine tetraacetic acid as stabilizer. Silica-coated CdSe QDs were made in water-in-oil microemulsion, while amino groups were introduced synchronously onto the nanoparticles by copolymerization of 3-aminopropyl- trimethoxysilane and tetraethyl orthosilicate. The results of TEM imaging, fluorescent spectroscopy and photostability tests show that the QDs are of uniform spherical size (200±8 nm), monodispersity, and high fluorescence and photostability.
基金Supported by National Natural Science Foundation of China (No. 40830744 and 40973073)National Key Technology R&D Program in the 11th Five-year Plan of China (No. 2008BAC32B03)+2 种基金Shanghai Leading Academic Discipline Project (No. S30109)Science and Technology Commission of Shanghai Municipality (No. 09ZR1411300 A.10-0111-07-003)
文摘Polybrominated diphenyl ethers (PBDEs) spread widely in the environment are mainly removed by photochemical and anaerobic microbial degradation. In this paper, the decomposition of 4-bromodiphenyl ether (BDE -3), the PBDEs homologues, is investigated by electron beam irradiation of its ethanol/water solution (reduction system) and acetonitrile/water solution (oxidation system). The radiolytic products were determined by GC coupled with electron capture detector, and the reaction rate constant of esol– in the reduction system was measured at 2.7×1010 L·mol–1·s–1 by pulsed radiolysis. The results show that the BDE-3 concentration affects strongly the decomposition ratio in the alkali solution, and the reduction system has a higher BDE-3 decomposition rate than the oxidation system. This indicates that the BDE-3 was reduced by effectively capturing esol– in radiolytic process.
文摘This paper describes the industrial electron accelerators of the ILU type and their usage for sterilization.The ILU machines produced by Budker Institute of Nuclear Physics have energy range of 0.8-10 MeV and beam power up to 100 kW,and they are working in industries all over the world.The ILU-10 and ILU-14 machines are described as well as the industrial sterilization facility based on ILU-6,ILU-10 and ILU-14 machines.
