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个人中子剂量气泡探测器研制 总被引:2,自引:0,他引:2
中子固体气泡探测器被认为是唯一能够满足国际辐射防护委员会ICRP60要求的个人中子剂量计,它具有从低能中子到高能中子的平坦响应曲线和对γ射线不灵敏的优点.本工作将过热液滴均匀地分布在一种软聚合物中,制成了个人中子气泡剂量计,其灵敏度达到每毫雷姆40个气泡.还介绍了个人中子剂量气泡探测器的原理和制作过程.Neutron solid bubble detector was considered as a unique one for meeting the need of the personal neutron dosimeter recommended by International Committee of radiation protection,ICRP60.It has the flat response for neutron from low energy to high energy,and insensitive for gamma rays. In this work,superheated liquid drops were dispersed into a kind of soft polymer homogeneously.A personal neutron bubble dosimeter has been made,and the sensitivity reached to about 40bubbles/mrem.The principle and the processing procedure of bubble detector were also introduced in this paper. 相似文献
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《力学与实践》中有关虚功原理的讨论引起了我们的兴趣。我们发现在以往的著作中对虚功原理充分性的证明普通有不妥之处,有必要加以严格论证。一、以往证明的不妥之处1.许多教科书中的充分性证明,例如文[1]认为,当一个原先静止的质点因不平衡而开始运动时,其动能的一阶增量dE_h>0。我们认为动能的增量确实大于零,即△E_h>0即 ... 相似文献
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瞬发γ中子活化分析是重要的核分析方法之一,是H和B等轻元素的重要分析手段,近年来应用范围不断增加.概要介绍了瞬发γ中子活化分析的基本原理,重点介绍了中国原子能科学研究院重水研究堆热中子束瞬发γ中子活化分析实验装置以及50 keV-11 MeV的宽能区γ效率刻度方法.还应用瞬发γ中子活化分析分析了海底锰结核标准物质GSPN 3中11种元素,结果与标准值基本一致.Neutron induced prompt γ activation analysis(PGNAA),is one of the nuclear analytical method,which is a powerful tool for H,B,etc.undestructive determination.The applications of PGNAA are increased in recent years.In this paper,the basic principle of PGNAA was introduced briefly.The facilities of PGNAA in HWRR of China Institute of Atomic Energy as well as the efficiency calibration for a wide range gamma from 50 keV to 10 MeV were emphasized.A deep sea polymetallic nodule CRM,GSPN 3 was analyzed by using PGNAA in this work,the results have agreement with the certified values. 相似文献
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用时间微分扰动角关联方法测量了LaFeO3纳米中的电四极超精细相互作用. 扰动角关联探针核14057La 14058Ce由139La(n,γ)140La反应产生, 实验只观察到一个La晶位的四极相互作用. 在室温下, 20和40 nm 以及晶体LaFeO3的四极相互作用频率ω0分别为 687.4 , 698.3 和742.9 Mrad/s , 频率分布宽度系数σ分别为 0.014, 0.009和0.001, 电场梯度不对称系数η=0. 实验数据表明, 电场梯度主轴与晶轴方向一致; 样品具有菱方结构, 晶体到纳米发生菱方向正交结构转变, 纳米尺度越小, 越趋于正交结构; 由于邻近核的扰动, 随纳米颗粒增大, 四极相互作用频率分布宽度系数σ变小, 晶体时最小. The quadrupole interactions in the nano and crystalline LaFeO3 perovskites have been investigated by TDPAC. The TDPAC probing nuclei 14057La 14058Ce were produced through the nuclear reaction 139La(n.γ)140La at the CIAE heavy water experimental reactor. One electric quadrupole interaction was detected for each material, which is assigned to the La site. The quadrupole interaction frequencies of 687.4, 698.3 and 742.9 Mrad/s with a distribution coefficient of 0.014, 0.009 and 0.001 were observed at room temperature for the 20 and 40 nm nano LaFeO3 and crystalline LaFeO3, respectively. The fitting yielded the EFG asymmetry parameter η=0, which indicates that the principal axes of the EFG is aligned with the crystallographic axes. The experimental results show that the structure of crystalline LaFeO3 is rhombohedral, the changing of the structure towards the orthorhombic structure takes place from the crystalline LaFeO3 to the nano LaFeO3, and the smaller the nano grain size, the larger the change. The frequency distribution is caused by the perturbation of the neighboring atoms, and thus, the distribution coefficient increases with decreasing the nano grain size and the crystalline LaFeO3 arrives at its maximum. 相似文献
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