Dose inter-comparison studies for Co γ-ray and 10 MeV electron beam irradiation were carried out 60 from July to October in 2002. The purpose of the studies was to check the reliability of the alanine-PE film dosime-...Dose inter-comparison studies for Co γ-ray and 10 MeV electron beam irradiation were carried out 60 from July to October in 2002. The purpose of the studies was to check the reliability of the alanine-PE film dosime- ters made by CIAE, which will be used as transfer standard dosimetry system mainly for electron beam irradiation. The expanded uncertainty of CIAE alanine/EPR dosimetry system was 4.1% for doses not higher than 10 kGy and 5.4% for those above 10 kGy (k=2). CIAE alanine-PE film dosimeters were sent to JAERI, RISO (National Labora- tory in Denmark) and INCT respectively, which were irradiated by Co gamma-rays or electron beams in each labo- 60 ratory. The irradiated dosimeters were then sent back to CIAE for electron paramagnetic resonance (EPR) analysis. The agreements were obtained to be ±1.9% for gamma-ray dose measurement and ±4.3% for electron beam dose measurement, which were all within the combined uncertainty of the reference and CIAE alanine/EPR dosimetry system. Furthermore, the overall mean ratio was found to be 0.995 with 1.8% in the coefficient of variation (CV). The preliminary inter-comparison studies indicated that CIAE film alanine/EPR dosimetry system had the potential to be used as a transfer dosimetry system for high dose measurement.展开更多
In this paper,the natural rubber is chosen as the main constituents for the transition layer of all-steel load radial tyre,which is pre-vulcanized by 500-keV E-beam irradiation of up to 60 kGy.The results show that th...In this paper,the natural rubber is chosen as the main constituents for the transition layer of all-steel load radial tyre,which is pre-vulcanized by 500-keV E-beam irradiation of up to 60 kGy.The results show that the green strength of transitional layer increases with the dose,reaching four times as much as the control(without irradiation) at 60 kGy.The final mechanical properties do not differ significantly from those of the control except that the aging and fatigue performance increased.However,thickness of the natural rubber transitional layer for an average single tyre can be reduced by 1 mm(or 1.5 kg) without obvious adverse effect on tyre performance.展开更多
Poly[bis(phenoxyphosphazene)](PBPP) and magnesium hydroxide(MH) are used as a flame retardant blend with low-density polyethylene(LDPE) for the nuclear cable. This study aims to investigate the effects of PBPP in MH-L...Poly[bis(phenoxyphosphazene)](PBPP) and magnesium hydroxide(MH) are used as a flame retardant blend with low-density polyethylene(LDPE) for the nuclear cable. This study aims to investigate the effects of PBPP in MH-LDPE blend composites on flame retardance and electron beam irradiation. The structure, morphology,and properties of the blend composites irradiated by an electron beam to different absorbed doses were characterized. The results indicated that PBPP provides lubrication during processing. As the PBPP content in the blend increases the melt flow rate at 20 phr MH, meaning the material is easier to process. The higher the PBPP content, the higher the limiting-oxygen index. The elongation at the break of the PBPP containing composites(at 50 phr MH) was evidently higher than the non-PBPP ones at different absorbed doses by electron beam irradiation. The thermogravimetric analysis results indicated that the improved mechanical property, resulting from electron-beam irradiation, could be attributed to the consumption of PBPP.展开更多
The gel dosimeter has the uniquely capacity in recording radiation dose distribution in three dimensions(3D), which has the specific advantages in dosimetry measurements where steep dose gradients exist. In this study...The gel dosimeter has the uniquely capacity in recording radiation dose distribution in three dimensions(3D), which has the specific advantages in dosimetry measurements where steep dose gradients exist. In this study, a novel radiochromic gel dosimeter was developed by dispersing nanovesicles self-assembled by 10,12-pentacosadiynoic acid(PCDA) into the tissue equivalence gel matrix. The characteristics of radiochromic PCDA vesicle gel dosimeters were evaluated. Results indicate that these radiochromic gel dosimeters have good linear response to 1.7 Me V electron beam irradiation in the dose range of 0.32–6.36 k Gy. In addition,the radiochromic gel dosimeters overcome the limitations of the existing gel dosimeters such as diffusion effect,post-radiation effect, and poor forming ability. Hence, the radiochromic PCDA vesicle gel dosimeters developed could be generally applied to 3D dose distribution measurement with optical readout.展开更多
Irradiation treatment of sewage sludge was carried out using an electron beam accelerator.The effects of irradiation dose,sludge water content and sludge thickness on the breakdown of sludge flocs,thus the formulation...Irradiation treatment of sewage sludge was carried out using an electron beam accelerator.The effects of irradiation dose,sludge water content and sludge thickness on the breakdown of sludge flocs,thus the formulation of soluble chemical oxygen demand (SCOD) and soluble total nitrogen (STN),and the reduction of MLSS and endogenous OUR,and so on,were investigated.It was observed that,with increased doses,the SCOD,STN and UV absorption intensity of the sludge supernatant increased rapidly with similar trends,and MLSS considerably decreased,all indicating that a large amount of the cell contents of sewage sludge were released by electron beam irradiation.The results of endogenous OUR also showed that a large number of microorganisms in sewage sludge were killed or deactivated.Zeta potential sludge became more positive with increased doses,implying that the dewatering performance of sewage sludge was not adversely affected.It was also found that the thickness of sludge was an operation parameter of great importance in the electron beam treatment of sewage sludge due to the relatively short penetration depth in water/sludge of the high-energy electrons.展开更多
Objective To determine the efficacy of palliative radiotherapy in treating tumor-stage cutaneous T-cell lymphoma/mycosis fungoides(MF).Methods From January 2008 to January 2013,a total of 11 patients with tumor-stage ...Objective To determine the efficacy of palliative radiotherapy in treating tumor-stage cutaneous T-cell lymphoma/mycosis fungoides(MF).Methods From January 2008 to January 2013,a total of 11 patients with tumor-stage MF were treated with local radiation therapy in Peking Union Medical College Hospital.The median age of these patients was 53.36±14.45 years.Female-male ratio was 1:1.2.The average course of disease was 10.82±3.37 years.All the patients were treated with local electronic beam irradiation with a total median dosage of 48.55±9.51(40-74) Gy in an average of 24.55±5.57(20-40) fractions,5 fractions per week.Results The median follow-up time was 55.27±29.3(13-103) months.No severe acute or chronic side effects of irradiation were observed.Complete clinical response(CR) rate of the radiated sites was 54.5%(6/11),partial response(PR) rate was 36.4%(4/11),and the overall response rate(CR+PR) was 90.9%.One patient showed no response.Conclusion Local radiotherapy with psolaren plus ultraviolet A and/or interferon maintaining treatment is an effective palliative therapy in the treatment of tumor-stage MF patients.展开更多
文摘Dose inter-comparison studies for Co γ-ray and 10 MeV electron beam irradiation were carried out 60 from July to October in 2002. The purpose of the studies was to check the reliability of the alanine-PE film dosime- ters made by CIAE, which will be used as transfer standard dosimetry system mainly for electron beam irradiation. The expanded uncertainty of CIAE alanine/EPR dosimetry system was 4.1% for doses not higher than 10 kGy and 5.4% for those above 10 kGy (k=2). CIAE alanine-PE film dosimeters were sent to JAERI, RISO (National Labora- tory in Denmark) and INCT respectively, which were irradiated by Co gamma-rays or electron beams in each labo- 60 ratory. The irradiated dosimeters were then sent back to CIAE for electron paramagnetic resonance (EPR) analysis. The agreements were obtained to be ±1.9% for gamma-ray dose measurement and ±4.3% for electron beam dose measurement, which were all within the combined uncertainty of the reference and CIAE alanine/EPR dosimetry system. Furthermore, the overall mean ratio was found to be 0.995 with 1.8% in the coefficient of variation (CV). The preliminary inter-comparison studies indicated that CIAE film alanine/EPR dosimetry system had the potential to be used as a transfer dosimetry system for high dose measurement.
基金Supported by Henan Province-Chinese Academy of Sciences Cooperation project(No.092106000021)the Scientific and Technological Brainstorm project of Erqi District,Zhengzhou City(No.20103315)
文摘In this paper,the natural rubber is chosen as the main constituents for the transition layer of all-steel load radial tyre,which is pre-vulcanized by 500-keV E-beam irradiation of up to 60 kGy.The results show that the green strength of transitional layer increases with the dose,reaching four times as much as the control(without irradiation) at 60 kGy.The final mechanical properties do not differ significantly from those of the control except that the aging and fatigue performance increased.However,thickness of the natural rubber transitional layer for an average single tyre can be reduced by 1 mm(or 1.5 kg) without obvious adverse effect on tyre performance.
基金Supported by the"Strategic Priority Research Program"of the Chinese Academy of Sciences(No.XDA02040300)
文摘Poly[bis(phenoxyphosphazene)](PBPP) and magnesium hydroxide(MH) are used as a flame retardant blend with low-density polyethylene(LDPE) for the nuclear cable. This study aims to investigate the effects of PBPP in MH-LDPE blend composites on flame retardance and electron beam irradiation. The structure, morphology,and properties of the blend composites irradiated by an electron beam to different absorbed doses were characterized. The results indicated that PBPP provides lubrication during processing. As the PBPP content in the blend increases the melt flow rate at 20 phr MH, meaning the material is easier to process. The higher the PBPP content, the higher the limiting-oxygen index. The elongation at the break of the PBPP containing composites(at 50 phr MH) was evidently higher than the non-PBPP ones at different absorbed doses by electron beam irradiation. The thermogravimetric analysis results indicated that the improved mechanical property, resulting from electron-beam irradiation, could be attributed to the consumption of PBPP.
基金Supported by National Natural Science Foundation of China(No.81301934)the Science and Technology Development Foundation of China Academy of Engineering Physics(No.2013B0301035)
文摘The gel dosimeter has the uniquely capacity in recording radiation dose distribution in three dimensions(3D), which has the specific advantages in dosimetry measurements where steep dose gradients exist. In this study, a novel radiochromic gel dosimeter was developed by dispersing nanovesicles self-assembled by 10,12-pentacosadiynoic acid(PCDA) into the tissue equivalence gel matrix. The characteristics of radiochromic PCDA vesicle gel dosimeters were evaluated. Results indicate that these radiochromic gel dosimeters have good linear response to 1.7 Me V electron beam irradiation in the dose range of 0.32–6.36 k Gy. In addition,the radiochromic gel dosimeters overcome the limitations of the existing gel dosimeters such as diffusion effect,post-radiation effect, and poor forming ability. Hence, the radiochromic PCDA vesicle gel dosimeters developed could be generally applied to 3D dose distribution measurement with optical readout.
文摘Irradiation treatment of sewage sludge was carried out using an electron beam accelerator.The effects of irradiation dose,sludge water content and sludge thickness on the breakdown of sludge flocs,thus the formulation of soluble chemical oxygen demand (SCOD) and soluble total nitrogen (STN),and the reduction of MLSS and endogenous OUR,and so on,were investigated.It was observed that,with increased doses,the SCOD,STN and UV absorption intensity of the sludge supernatant increased rapidly with similar trends,and MLSS considerably decreased,all indicating that a large amount of the cell contents of sewage sludge were released by electron beam irradiation.The results of endogenous OUR also showed that a large number of microorganisms in sewage sludge were killed or deactivated.Zeta potential sludge became more positive with increased doses,implying that the dewatering performance of sewage sludge was not adversely affected.It was also found that the thickness of sludge was an operation parameter of great importance in the electron beam treatment of sewage sludge due to the relatively short penetration depth in water/sludge of the high-energy electrons.
文摘Objective To determine the efficacy of palliative radiotherapy in treating tumor-stage cutaneous T-cell lymphoma/mycosis fungoides(MF).Methods From January 2008 to January 2013,a total of 11 patients with tumor-stage MF were treated with local radiation therapy in Peking Union Medical College Hospital.The median age of these patients was 53.36±14.45 years.Female-male ratio was 1:1.2.The average course of disease was 10.82±3.37 years.All the patients were treated with local electronic beam irradiation with a total median dosage of 48.55±9.51(40-74) Gy in an average of 24.55±5.57(20-40) fractions,5 fractions per week.Results The median follow-up time was 55.27±29.3(13-103) months.No severe acute or chronic side effects of irradiation were observed.Complete clinical response(CR) rate of the radiated sites was 54.5%(6/11),partial response(PR) rate was 36.4%(4/11),and the overall response rate(CR+PR) was 90.9%.One patient showed no response.Conclusion Local radiotherapy with psolaren plus ultraviolet A and/or interferon maintaining treatment is an effective palliative therapy in the treatment of tumor-stage MF patients.
