A temperature measurement device can produce data deviations and can even be damaged in a high-dose radiation environment.To reduce the radiation damage to such a device and improve the temperature measurement accurac...A temperature measurement device can produce data deviations and can even be damaged in a high-dose radiation environment.To reduce the radiation damage to such a device and improve the temperature measurement accuracy in a radiation environment,a temperature sensor based on optical-fiber sensing technology is proposed.This sensor has a cascade structure composed of a single-mode fiber(SMF),a dispersion-compensation fiber(DCF),a nocore fiber(NCF),and another SMF(SDNS).The DCF and NCF are coated with a polydimethylsiloxane(PDMS)film,which is a heat-sensitive material with high thermal optical and thermal expansion coefficients.In experiments,PDMS was found to produce an irradiation crosslinking effect after irradiation,which improved the temperature sensitivity of the SDNS sensor.The experimental results showed that within a range of 30–100℃,the maximum temperature sensitivity after irradiation was 62.86 pm/℃,and the maximum transmission sensitivity after irradiation was 3.353×10^(-2)dB/℃,which were 1.22 times and 2.267 times the values before irradiation,respectively.In addition,repeated temperature experiments verified that the SDNS sensor coated with the PDMS film had excellent temperature repeatability.Furthermore,it was found that with an increase in the irradiation intensity,the irradiation crosslinking degree of PDMS increased,and the temperature sensitivity of the sensor was improved.The proposed sensor could potentially be applied to temperature measurement in a nuclear-radiation environment.展开更多
Auditory cortical cvokod rcsponse(ACER) and auditory brainstom cvoked response (ABR) were recorded in guinea pigs before and after irradiation of ^(60)Co γ-ray. A single dose of irradiation on head was 90Gy and 70Gy ...Auditory cortical cvokod rcsponse(ACER) and auditory brainstom cvoked response (ABR) were recorded in guinea pigs before and after irradiation of ^(60)Co γ-ray. A single dose of irradiation on head was 90Gy and 70Gy in two groups, respectively. Two h after irradiation. the threshold shift was 12. 5 dB and 9 dB, and the ACER post-irradiation amplitude ex- ceeded the maximum pre-irradiation value by 20% and 37%. Six h after irradiation, the threshold shift increased to 37 dB and the maximum amplitnde decreased to the level of pre-irradiation in 70Gy-group. In another group, right auditory bulla arca was irradiated with a total dose of 45Gy in a course of six fractions/two weeks. Fourteen d after irradiation, the threshold shift of ABR was 118 dB and the latency of wave I was longer. The amplitude-intensity curve was after irradiation. Histological observation using scanning showed that only outer hair- cells in the basal coil of the cochlea were 6 h after irrdiation 50Gy-group. Bul 16 h later, outer, hair cells in all coils of the cochlea were found to be destroyed extensively and inner cells were destroyed slightly. In 45Gy-group, 14 d after irradiation, outer hair cells in all coils of the cochlea were damaged and no inmer hair cell was injured severely.展开更多
In order to explore the effect of radiation breeding on new germplasm innovation of Pteroceltis tatarinowii,the dry seeds of P.tatarinowii from Lingyan Temple were used as test materials in this study,which were irrad...In order to explore the effect of radiation breeding on new germplasm innovation of Pteroceltis tatarinowii,the dry seeds of P.tatarinowii from Lingyan Temple were used as test materials in this study,which were irradiated by ^(60)Co-γ rays with different radiation doses.The results showed that the emergence rate decreased with the increase of radiation dose,the emergence rate of low dose below 200 Gy decreased slowly,and the emergence rate of high dose above 200 Gy decreased sharply;when the radiation dose ranged from 100 to 200 Gy,the mutagenic effect of P.tatarinowii seeds was the best;and radiation obviously affected the leaf color and leaf shape of seedlings.This study provides original materials for the cultivation of new P.tatarinowii varieties and the study of color-changing mechanism.展开更多
This paper gives a detailed description of a radiological accident of ^(192)Ir source occurring on May 7,2014 in Nanjing,China(the 5⋅7 accident),encompassing a combination of accident overview,emergency response,inves...This paper gives a detailed description of a radiological accident of ^(192)Ir source occurring on May 7,2014 in Nanjing,China(the 5⋅7 accident),encompassing a combination of accident overview,emergency response,investigation process and results,dose estimation,medical treatment,experience and lessons learnt.The investigation showed that the accident was mainly caused by insufficient attention to the radiation safety,non-compliance with licensing conditions and employment of untrained temporary radiographer without equipped with alarm dosimeters.Additionally,no area radiation survey meter was used to verify whether the source would have retracted to radiography camera after every exposure.It therefore is the important means to strengthen the management of radioactive source safety and put the strict management measures in place,implement the requirements for personnel qualification management,strengthen regulatory inspection and actively poster safety culture,which are necessary to avoid accidents.This paper aims to provide experience and reference for the emergency response and countermeasure of radiological accidents involving industrial radioactive sources.展开更多
Through different dose-rate switching evaluation methods,the radiation-response rules of operational amplifiers are studied when the irradiation dose rate is switched from high to low under different radiation tempera...Through different dose-rate switching evaluation methods,the radiation-response rules of operational amplifiers are studied when the irradiation dose rate is switched from high to low under different radiation temperatures and total doses. The experimental results indicate that the response characteristics could be affected by the switching total doses, irradiation temperatures,and dose rates individually or together. Accelerated evaluation on the ELDRS can be realized by adopting a proper dose-rate switching method. Meanwhile, the irradiation time can also be reduced. Finally, the mechanisms of the difference between various radiation responses are analyzed.展开更多
基金the National Natural Science Foundation of China(Nos.62075057 and 11975091)the Program for Innovative Research Team(in Science and Technology)in University of Henan Province(No.21IRTSTHN011).
文摘A temperature measurement device can produce data deviations and can even be damaged in a high-dose radiation environment.To reduce the radiation damage to such a device and improve the temperature measurement accuracy in a radiation environment,a temperature sensor based on optical-fiber sensing technology is proposed.This sensor has a cascade structure composed of a single-mode fiber(SMF),a dispersion-compensation fiber(DCF),a nocore fiber(NCF),and another SMF(SDNS).The DCF and NCF are coated with a polydimethylsiloxane(PDMS)film,which is a heat-sensitive material with high thermal optical and thermal expansion coefficients.In experiments,PDMS was found to produce an irradiation crosslinking effect after irradiation,which improved the temperature sensitivity of the SDNS sensor.The experimental results showed that within a range of 30–100℃,the maximum temperature sensitivity after irradiation was 62.86 pm/℃,and the maximum transmission sensitivity after irradiation was 3.353×10^(-2)dB/℃,which were 1.22 times and 2.267 times the values before irradiation,respectively.In addition,repeated temperature experiments verified that the SDNS sensor coated with the PDMS film had excellent temperature repeatability.Furthermore,it was found that with an increase in the irradiation intensity,the irradiation crosslinking degree of PDMS increased,and the temperature sensitivity of the sensor was improved.The proposed sensor could potentially be applied to temperature measurement in a nuclear-radiation environment.
文摘Auditory cortical cvokod rcsponse(ACER) and auditory brainstom cvoked response (ABR) were recorded in guinea pigs before and after irradiation of ^(60)Co γ-ray. A single dose of irradiation on head was 90Gy and 70Gy in two groups, respectively. Two h after irradiation. the threshold shift was 12. 5 dB and 9 dB, and the ACER post-irradiation amplitude ex- ceeded the maximum pre-irradiation value by 20% and 37%. Six h after irradiation, the threshold shift increased to 37 dB and the maximum amplitnde decreased to the level of pre-irradiation in 70Gy-group. In another group, right auditory bulla arca was irradiated with a total dose of 45Gy in a course of six fractions/two weeks. Fourteen d after irradiation, the threshold shift of ABR was 118 dB and the latency of wave I was longer. The amplitude-intensity curve was after irradiation. Histological observation using scanning showed that only outer hair- cells in the basal coil of the cochlea were 6 h after irrdiation 50Gy-group. Bul 16 h later, outer, hair cells in all coils of the cochlea were found to be destroyed extensively and inner cells were destroyed slightly. In 45Gy-group, 14 d after irradiation, outer hair cells in all coils of the cochlea were damaged and no inmer hair cell was injured severely.
基金Supported by"Innovation Driving and Leading Promotion of Seedling and Flower Industry in Mount Tai"of Industrial Upgrading Project of Science and Technology Park in Shandong Province(2019YQ012)"Collection,Preservation and Accurate Identification of Germplasm Resources of Precious Timber Tree Species"of Shandong Provincial Agricultural Elite Varieties Project(2019LZGC01804).
文摘In order to explore the effect of radiation breeding on new germplasm innovation of Pteroceltis tatarinowii,the dry seeds of P.tatarinowii from Lingyan Temple were used as test materials in this study,which were irradiated by ^(60)Co-γ rays with different radiation doses.The results showed that the emergence rate decreased with the increase of radiation dose,the emergence rate of low dose below 200 Gy decreased slowly,and the emergence rate of high dose above 200 Gy decreased sharply;when the radiation dose ranged from 100 to 200 Gy,the mutagenic effect of P.tatarinowii seeds was the best;and radiation obviously affected the leaf color and leaf shape of seedlings.This study provides original materials for the cultivation of new P.tatarinowii varieties and the study of color-changing mechanism.
文摘This paper gives a detailed description of a radiological accident of ^(192)Ir source occurring on May 7,2014 in Nanjing,China(the 5⋅7 accident),encompassing a combination of accident overview,emergency response,investigation process and results,dose estimation,medical treatment,experience and lessons learnt.The investigation showed that the accident was mainly caused by insufficient attention to the radiation safety,non-compliance with licensing conditions and employment of untrained temporary radiographer without equipped with alarm dosimeters.Additionally,no area radiation survey meter was used to verify whether the source would have retracted to radiography camera after every exposure.It therefore is the important means to strengthen the management of radioactive source safety and put the strict management measures in place,implement the requirements for personnel qualification management,strengthen regulatory inspection and actively poster safety culture,which are necessary to avoid accidents.This paper aims to provide experience and reference for the emergency response and countermeasure of radiological accidents involving industrial radioactive sources.
文摘Through different dose-rate switching evaluation methods,the radiation-response rules of operational amplifiers are studied when the irradiation dose rate is switched from high to low under different radiation temperatures and total doses. The experimental results indicate that the response characteristics could be affected by the switching total doses, irradiation temperatures,and dose rates individually or together. Accelerated evaluation on the ELDRS can be realized by adopting a proper dose-rate switching method. Meanwhile, the irradiation time can also be reduced. Finally, the mechanisms of the difference between various radiation responses are analyzed.
