In this paper,gaseous products generated by radiation degradation of N,N-diethylhydroxylamine (DEHA) in aqueous solution are studied.The results show that by 10～1000 kGy irradiation of the solution in DEHA concentrat...In this paper,gaseous products generated by radiation degradation of N,N-diethylhydroxylamine (DEHA) in aqueous solution are studied.The results show that by 10～1000 kGy irradiation of the solution in DEHA concentration of 0.1～0.5 mol·L^(-1),the gaseous products were mainly hydrogen,methane,ethane and ethene.The volume fraction of hydrogen did not change much with different concentrations of DEHA.The volume fraction of methane and ethane decreased,but that of ethene increased,with increasing DEHA concentration.The volume fraction of hydrogen,methane and ethane increased with the dose.The relationship of the volume fraction of ethene with the dose had something to do with the DEHA concentration.展开更多
The trace water-soluble radiolytic products of neat 1-butyl-3-methylimidazolium hexafluorophosphate([C4mim][PF6]) were identified by analysing water-washed samples of γ-irradiated ionic liquids. HF and difluorophosph...The trace water-soluble radiolytic products of neat 1-butyl-3-methylimidazolium hexafluorophosphate([C4mim][PF6]) were identified by analysing water-washed samples of γ-irradiated ionic liquids. HF and difluorophosphinic acid were confirmed as the main radiolytic products of [C4mim][PF6], and their radiation chemical yields were quantified by19 F NMR(G(F-) = 0.14 μmol/J, G(HOP(O)F2) = 0.053 μmol/J). Compared to [C4mim][NTf2], [C4mim][PF6] shows better radiation stability.展开更多
In this work,the 0.1-0.5 mol·L-1 N,N-dimethylhydroxylamine(DMHA) were irradiated to 5-25 kGy,and gaseous products of mainly hydrogen,methane,ethane and n-butane were measured by gas chromatography.The results sho...In this work,the 0.1-0.5 mol·L-1 N,N-dimethylhydroxylamine(DMHA) were irradiated to 5-25 kGy,and gaseous products of mainly hydrogen,methane,ethane and n-butane were measured by gas chromatography.The results show that the volume fraction of hydrogen and methane increases with the concentration of DMHA and dose,and the latter does not change markedly at high doses.展开更多
In this study, the gamma radiation shielding features of several environmentally friendly materials were investigated. For this purpose, several attenuation parameters, such as the mass attenuation coefficient (l=q), ...In this study, the gamma radiation shielding features of several environmentally friendly materials were investigated. For this purpose, several attenuation parameters, such as the mass attenuation coefficient (l=q), radiation protection efficiency (RPE), and effective atomic number (Zeff) were determined experimentally and compared with numerical data obtained using WinXCom software. In the measurements, the emitted gamma photons were counted by a gamma spectrometer equipped with an HPGe detector using 22Na, 54Mn, 57Co, 60Co, 133Ba, and 137Cs radioactive point sources in the energy region of 81–1333 keV. The obtained results indicate that the l=q and RPE values of the samples decrease with an increase in photon energy. The experimental values are in good agreement with those obtained using WinXCom software. The RPE and Zeff results show that among the studied materials, the NaY0.77Yb0.20Er0.03F4 sample has the best gamma radiation shielding effectiveness.展开更多
In this paper, various kinds of monomers 2-hydroxyethyl methacrylate (HEMA), 2-hydroxyethyl acrylate (HEA), hydroxypropyl methacrylate (HPMA) and methoxy polyethylene glycol methylacrylate (M-23G) were eopolymerized b...In this paper, various kinds of monomers 2-hydroxyethyl methacrylate (HEMA), 2-hydroxyethyl acrylate (HEA), hydroxypropyl methacrylate (HPMA) and methoxy polyethylene glycol methylacrylate (M-23G) were eopolymerized by radiation technique at low temperature (-78℃) and several kinds of copolymer carriers were obtained. Yeast cells were immobilized through adhesion and multiplication of yeast cells themselves on these carriers. The etharol productivity of immobilized yeast cells with these carriers was related to the monomer composition and water content of copolymer carriers and the optimum monomer composition was 20%:10% in poly (HEA-M23G). In this case, the ethanol productivity of immobilized yeast cells was 26 mg /( ml·h), which was 4 times as high as that of free cells. In this study, the effect of adding of crosslinking reagent (4G) in copolymer on activity of yeast cells immobilized with the carriers were also studied. It was found that the effect of adding crosslinking reagent (4G) in lower monomer composition of poly(HEA-M23G) on the ethanol productivity of immobilized cells was better than that in higher one in this work.展开更多
As a potential matrix of three-dimensional gel dosimeter, agarose hydrogels will be used for measuring radiation doses, hence the importance of studying their radiation resistance and radiolysis mechanism. Physical pr...As a potential matrix of three-dimensional gel dosimeter, agarose hydrogels will be used for measuring radiation doses, hence the importance of studying their radiation resistance and radiolysis mechanism. Physical property and chemical structure of physically cross-linked agarose hydrogel samples irradiated to 0–200 k Gy by60 Co γ-rays were analyzed by universal testing machine, gel permeation chromatography, fourier transform infrared spectrometer, ultraviolet visible spectroscopy, nuclear magnetic resonance, and gas chromatography. The results showed that agarose hydrogels had good radiation stability below 25 k Gy, and the maximum compression strength of sample was ca. 0.1 MPa at 25 k Gy. The irradiated samples degraded obviously and liquefied gradually with increasing doses. Compared with unirradiated sample, carbonyl groups, which generated from the molecular chains of agarose hydrogels, were observed at 25 k Gy and increased gradually with dose. The main gas products evolved from irradiated agarose hydrogels were H2, CO2, CO and CH4. Based on the analysis of radiolytic products, the radiolysis mechanism of agarose hydrogels under γ-radiation was proposed.展开更多
基金Natural Science Foundation of China (Contract No.20771074)Shanghai Leading Academic Disciplines (Contract No.T0105)
文摘In this paper,gaseous products generated by radiation degradation of N,N-diethylhydroxylamine (DEHA) in aqueous solution are studied.The results show that by 10～1000 kGy irradiation of the solution in DEHA concentration of 0.1～0.5 mol·L^(-1),the gaseous products were mainly hydrogen,methane,ethane and ethene.The volume fraction of hydrogen did not change much with different concentrations of DEHA.The volume fraction of methane and ethane decreased,but that of ethene increased,with increasing DEHA concentration.The volume fraction of hydrogen,methane and ethane increased with the dose.The relationship of the volume fraction of ethene with the dose had something to do with the DEHA concentration.
基金Supported by the National Natural Science Foundation of China(Nos.91126014 and 11079007)the Research Fund for the Doctoral Program of Higher Education of China(No.20100001110021)
文摘The trace water-soluble radiolytic products of neat 1-butyl-3-methylimidazolium hexafluorophosphate([C4mim][PF6]) were identified by analysing water-washed samples of γ-irradiated ionic liquids. HF and difluorophosphinic acid were confirmed as the main radiolytic products of [C4mim][PF6], and their radiation chemical yields were quantified by19 F NMR(G(F-) = 0.14 μmol/J, G(HOP(O)F2) = 0.053 μmol/J). Compared to [C4mim][NTf2], [C4mim][PF6] shows better radiation stability.
基金Supported by Natural Science Foundation of China(Contract No.20771074)Shanghai Leading Academic Disciplines(Contract No.S30109)
文摘In this work,the 0.1-0.5 mol·L-1 N,N-dimethylhydroxylamine(DMHA) were irradiated to 5-25 kGy,and gaseous products of mainly hydrogen,methane,ethane and n-butane were measured by gas chromatography.The results show that the volume fraction of hydrogen and methane increases with the concentration of DMHA and dose,and the latter does not change markedly at high doses.
文摘In this study, the gamma radiation shielding features of several environmentally friendly materials were investigated. For this purpose, several attenuation parameters, such as the mass attenuation coefficient (l=q), radiation protection efficiency (RPE), and effective atomic number (Zeff) were determined experimentally and compared with numerical data obtained using WinXCom software. In the measurements, the emitted gamma photons were counted by a gamma spectrometer equipped with an HPGe detector using 22Na, 54Mn, 57Co, 60Co, 133Ba, and 137Cs radioactive point sources in the energy region of 81–1333 keV. The obtained results indicate that the l=q and RPE values of the samples decrease with an increase in photon energy. The experimental values are in good agreement with those obtained using WinXCom software. The RPE and Zeff results show that among the studied materials, the NaY0.77Yb0.20Er0.03F4 sample has the best gamma radiation shielding effectiveness.
基金This research projcct was financed by applied base research fund of jiangsu provicial Scicntific and Tcchniquuc Committee from 1989-1991
文摘In this paper, various kinds of monomers 2-hydroxyethyl methacrylate (HEMA), 2-hydroxyethyl acrylate (HEA), hydroxypropyl methacrylate (HPMA) and methoxy polyethylene glycol methylacrylate (M-23G) were eopolymerized by radiation technique at low temperature (-78℃) and several kinds of copolymer carriers were obtained. Yeast cells were immobilized through adhesion and multiplication of yeast cells themselves on these carriers. The etharol productivity of immobilized yeast cells with these carriers was related to the monomer composition and water content of copolymer carriers and the optimum monomer composition was 20%:10% in poly (HEA-M23G). In this case, the ethanol productivity of immobilized yeast cells was 26 mg /( ml·h), which was 4 times as high as that of free cells. In this study, the effect of adding of crosslinking reagent (4G) in copolymer on activity of yeast cells immobilized with the carriers were also studied. It was found that the effect of adding crosslinking reagent (4G) in lower monomer composition of poly(HEA-M23G) on the ethanol productivity of immobilized cells was better than that in higher one in this work.
基金Supported by the Science and Technology Development Foundation of China Academy of Engineering Physics(No.2013B0301035)
文摘As a potential matrix of three-dimensional gel dosimeter, agarose hydrogels will be used for measuring radiation doses, hence the importance of studying their radiation resistance and radiolysis mechanism. Physical property and chemical structure of physically cross-linked agarose hydrogel samples irradiated to 0–200 k Gy by60 Co γ-rays were analyzed by universal testing machine, gel permeation chromatography, fourier transform infrared spectrometer, ultraviolet visible spectroscopy, nuclear magnetic resonance, and gas chromatography. The results showed that agarose hydrogels had good radiation stability below 25 k Gy, and the maximum compression strength of sample was ca. 0.1 MPa at 25 k Gy. The irradiated samples degraded obviously and liquefied gradually with increasing doses. Compared with unirradiated sample, carbonyl groups, which generated from the molecular chains of agarose hydrogels, were observed at 25 k Gy and increased gradually with dose. The main gas products evolved from irradiated agarose hydrogels were H2, CO2, CO and CH4. Based on the analysis of radiolytic products, the radiolysis mechanism of agarose hydrogels under γ-radiation was proposed.
