本文主要是对植入科学公司生产的模型3500碘-125植入治疗粒子源的一系列剂量学特征的研究。粒子源的各个剂量学参量通过使用蒙特卡罗方法计算得到。计算模型材料采用了两种等效水:固体水和液态水。粒子源的剂量学参量如剂量率常数、径...本文主要是对植入科学公司生产的模型3500碘-125植入治疗粒子源的一系列剂量学特征的研究。粒子源的各个剂量学参量通过使用蒙特卡罗方法计算得到。计算模型材料采用了两种等效水:固体水和液态水。粒子源的剂量学参量如剂量率常数、径向剂量函数和各项异性函数等的确定依照美国医学物理学家协会(American Association of Physicists in Medicine AAPM)第43次工作报告。蒙特卡罗模拟得到液态水的剂量率为0.997 cGyh-1U-1,固态水的为1.027 cGyh-1U-1。与前同类研究比较,本次研究的剂量率常数与同类研究所报道的数据较为一致。展开更多
The static recrystallization behavior of low-alloy steel Q345B during double-pass hot compression deformation tests was investigated in the temperature range of 900-1000 ℃,the true strain range of 0.15-0.25 and the i...The static recrystallization behavior of low-alloy steel Q345B during double-pass hot compression deformation tests was investigated in the temperature range of 900-1000 ℃,the true strain range of 0.15-0.25 and the interpass time range of 0.5-50 s on Gleeble-3500 thermo-simulation machine.The results show that static recrystallization during the interpass time is observed.As the deformation temperature and strain increase,softening caused by static recrystallization is obvious.According to the analysis and calculation of thermo-simulation data,the static recrystallization activation energy was obtained and static recrystallization kinetics model was built.Finally,the error analysis of static recrystallization kinetics model proved that the model had good accuracy.Therefore,this model provides a theoretical basis for static recrystallization（SRX）and will contribute to the development of multipass hot rolling process,in order to control the rolling process more accurately.展开更多
文摘本文主要是对植入科学公司生产的模型3500碘-125植入治疗粒子源的一系列剂量学特征的研究。粒子源的各个剂量学参量通过使用蒙特卡罗方法计算得到。计算模型材料采用了两种等效水:固体水和液态水。粒子源的剂量学参量如剂量率常数、径向剂量函数和各项异性函数等的确定依照美国医学物理学家协会(American Association of Physicists in Medicine AAPM)第43次工作报告。蒙特卡罗模拟得到液态水的剂量率为0.997 cGyh-1U-1,固态水的为1.027 cGyh-1U-1。与前同类研究比较,本次研究的剂量率常数与同类研究所报道的数据较为一致。
基金Item Sponsored by Fok Ying Tung Education Foundation(101048)Natural Science Foundation of Hebei Province of China(E2008000835)
文摘The static recrystallization behavior of low-alloy steel Q345B during double-pass hot compression deformation tests was investigated in the temperature range of 900-1000 ℃,the true strain range of 0.15-0.25 and the interpass time range of 0.5-50 s on Gleeble-3500 thermo-simulation machine.The results show that static recrystallization during the interpass time is observed.As the deformation temperature and strain increase,softening caused by static recrystallization is obvious.According to the analysis and calculation of thermo-simulation data,the static recrystallization activation energy was obtained and static recrystallization kinetics model was built.Finally,the error analysis of static recrystallization kinetics model proved that the model had good accuracy.Therefore,this model provides a theoretical basis for static recrystallization（SRX）and will contribute to the development of multipass hot rolling process,in order to control the rolling process more accurately.
