222Rn-220Rn分辨探测器的刻度与比对

为了保证测量质量,采用实验室新改进的^222Rn-^220Rn分辨探测器在南华大学氡实验室进行了刻度,并参加了日本NIRS组织的国际比对。结果显示,^222Rn-^220Rn暴露量与径迹密度之间有很好的线性关系,相关系数分别是0．9894、0．9885;^222Rn、^220Rn刻度因子分别为4．27±0．40Tacks cm^-2（kBq.m^-3．h）^-1、2．33±0．39 Tracks cm^-2（kBq·m^-3．h）^-1。纯^222Rn条件,测量值与NIRS提供的参考值的相对百分偏差（RPD）和变异系数（COV）分别为12％、7．7％,达到了英国NRPB规定的B级水平,在美国EPA规定的可接受的控制限之内;高^220Rn条件,^220Rn测量值的RPD和COV分别为22％、4．8％。有关^220Rn测量偏差偏高的原因有待进一步探讨。     

裂变产物核136Sn原子数的γ能谱法测定

裂变产物136Sn是一种长寿命纯β放射性核素，半衰期为（2．35±0．07）×10^5a。该核素是核工程对环境长期污染的重要指示核素，对于它的超高灵敏测量将为监测环境中的核污染提供重要的信息。     

地表空气中天然伽玛放射体的测量

本文提出一种估算空气中悬浮放射性核素的附着部分与非附着部分的简易方法,该方法同时采用纤维素与活性炭两种过滤器。利用伽玛射线能谱法系统地检测了近地表空气中一些原生放射性核素的浓度:~(40)K、~(226)Ra、~(212)Pb、~(214)Pb、~(208)Tl和~(214)Bi。同时还测定了宇宙成因的放射性核素~7Be的浓度。 这些元素总的放射性活度要比允许的平均值低,而且在大多数情况下,约为本底活度。该结果表明,~(214)Bi、~(212)Pb、~(214)Pb和~(208)Tl总是附着在气溶胶上,而~7Be、~(40)K和~(226)Ra处于非附着状态。 利用扫描电子显微镜测定了气溶胶的主要成分,发现有Si、Ca、Al、Cl和K。     

气溶胶样品中~7Be和~(210)Pb的提取技术

7Be和210Pb是HPGeγ谱仪系统效率刻度常用放射性核素。通过一系列的化学处理过程,可以将气溶胶样品中的7Be和210Pb提取转移至溶液中,用于制作效率刻度源。本工作研究了从气溶胶滤膜样品中提取7Be和210Pb的化学过程,确定了聚丙烯纤维气溶胶滤膜样品的灰化时间为5 h、灰化温度为500℃。通过灰化样品的消解实验,初步建立了气溶胶样品中7Be和210Pb的消解方法,实现了对气溶胶滤膜样品中7Be和210Pb的提取。     

151Sm半衰期及其γ射线强度测定

151Sm为裂变产物核素，有较高的裂变产额。本工作开展对151Sm半衰期的精确测定。151Sm利用反应堆照射通过150Sm（n，γ）反应得到。照射后经过冷却后利用热电离质谱对151Sm／150Sm原子比进行了测定，测定结果为151Sm／150Sm原子比=（3．750±0．002）×10^-3.     

广州地区大气环境气溶胶样品放射性特征

对广州地区大气环境气溶胶样品的总α、总β、~(210)Pb、~(210)Po和7Be进行了为期两年采样监测,分别得到各监测项目年平均放射性活度浓度分别为0.12 m Bq·m~(-3)、0.75 m Bq·m~(-3)、0.93 m Bq·m~(-3)、0.23 m Bq·m~(-3)、3.16 m Bq·m~(-3)。总α、总β、~(210)Pb、~(210)Po和7Be活度浓度变化有明显的季节性特征:总α、总β、~(210)Pb、~(210)Po、7Be活度浓度最低值均出现在9月,总α、总β活度浓度最高值出现在11月,~(210)Pb、~(210)Po活度浓度峰值出现在2月,7Be活度浓度峰值出现在1月,总体呈现出冬春高、夏秋低的特点;~(210)Pb、~(210)Po、7Be与PM10、PM2.5有较强正相关性,但~(210)Pb、~(210)Po倾向于与比表面积更大的PM2.5结合,而~7Be更易附着在较大粒径的PM10上。     

79Se—AMS测量样品的化学形式选择及其制备方法

中国原子能科学研究院的AMS小组在原蒋菘生、何明等对79Se—AMS测量的基础上，发展了基于SeO2-分子负离子引出形式的79Se—AMS测量方法，测量灵敏度由原来的3．0×10^-9提高到好于1．0×10^-12。     

79Se-AMS示踪研究亚毒性剂量亚硒酸钠摄入的硒代谢

长寿命放射性核素79Se的半衰期长达2．8×10^5a，其放射性比活度（单个原子的活度）约1×10^-14Bq。79Se衰变时仅放射出能量为150．7keY纯β射线，对生物组织甚至细胞的辐射损伤远小于75Se，而79Se的加速器质谱测量方法（795e—AMS）具有灵敏度高、相对测量准确性高以及测量精度高等特点，因而适合于长周期、无损伤的生物示踪研究。     

腐殖酸存在条件下镎胶体行为研究

腐殖酸广泛存在于土壤和水体中，具有较强配合能力、还原能力，并能在一定条件下形成胶体，影响核素化学形态，进而影响核素在地下水中的化学行为及溶解、吸附、扩散等迁移行为。锕系核素。237Np属高毒α核素，在放射性废物中含量较大、半衰期（2．14×10^7a）长.     

中子三轴谱仪输入谱模拟与优化计算

根据冷中子源及其后续中子导管的布局与参数,采用蒙特卡罗方法模拟计算了中子三轴谱仪的输入谱,获得了中子束均匀性、发散度及注量率等参数。模拟结果表明：冷源与导管人口间距离L不宜小于0.1m,在距离为0.5m时导管出口处注量率达到最大3.96×10^8cm^-2s^-1。;中子注量率及发散度均随导管超镜因子m增大而增大,m值由1.5增大到3后,其水平方向的发散度几乎不变,垂直方向最大发散度增大约87.7％,注量率增大25％;垂直方向和水平方向的发散均可以用高斯分布来描述,但水平方向的发散伴有离散峰;在m为1.5,L为2m情况下,束流水平和垂直方向的最大发散度分别为0.85°和0.81°,中子注量率为2.86×10^8cm^-2s^-1;得到了针对三轴谱仪的导管优化参数。     

Increase in internal friction in uranium with change in temperature

On the basis of the previously described increase in internal friction in uranium during heating, a semiquantitative evaluation was made of the dependence of increase in internal friction on the rate of heating, frequency and amplitude of vibrations. The results of the calculations agree satisfactorily with data obtained experimentally. A study was made of the effect of the initial state of the specimen on the increase in internal friction at the initial stages of heating.     

广东省进出口食品中的放射性检验

报道了广东省商检中心放射性检验室开展的广东进出口食品中的放射性检验工作。介绍了检验工作采用仪器的主要性能及应用；给出了分析测量方法和探测下限以及实验的质量保证措施，并给出了检验室测量的广东省几种食品中的放射性含量范围，测量结果与我国食品中放射性活度变化范围大体一致。     

微机在核物理实验应用中的抗干扰问题

本文简单介绍了计算机在核物理技术应用中的各种噪声，并初步探讨了抑制噪声的方法。     

Tritium concentrations in precipitation in Shanghai

Beamline BL17 U1 at Shanghai Synchrotron Radiation Facility is an energy-tunable macromolecular crystallography beamline that has been in user operation since 2009. Growing demand from the user community for a small beam and related experimental methods have motivated upgrades of the devices in the endstation.Minibeam modes have already been developed for operation. A self-integrated diffractometer reduces the sphere of confusion of the rotatory axis to 1μm. The new diffractometer is equipped with an upgraded on-axis viewing system that can improve the resolving power. Additionally,the area detector was also upgraded to the newest generation of detectors, the EIGER X 16 M, which can collect data at 133 Hz. After these upgrades, the endstation became virtually new. This paper covers the upgrade of the endstation devices and gives the first data collection results.     

2010年的美国铀矿业

2010年,美国铀矿总共施工7 209个钻孔,总进尺1 493 520 m;生产铀1 628.55t;铀矿业总支出费用为2.773亿美元,其中铀矿地勘费支出为3 450万美元,占铀矿业总费用的12.44％.铀矿地勘钻探费用为4 460万美元,占铀矿业总费用的16.08％.     

Tritium concentrations in precipitation in Shanghai

Tritium concentrations in precipitation can be used as a criterion to evaluate the tritium baseline of the environment. The tritium concentration in precipitation in Shanghai during 2014-2015 was determined. Values ranged from 0.68 ± 0.04 to 4.11 ± 0.39 Bq/L, and it showed a decreasing trend compared with historical data; however,the values were slightly higher than the natural background tritium level. Additionally, the tritium concentration shows a seasonal variation: It was higher in autumn and winter and lower in summer and spring. A comparison of concentrations in precipitation in Shanghai and around the Qinshan Nuclear Power Plant reveals no correlation,implying that the nuclear power plant operations may not affect the environment of Shanghai. Thus, the raised tritium concentrations in Shanghai might be due to the effects of monsoons, spring leak, raindrop, or other activities that generate tritium there. Those activities may include chemistry research that uses tritium as a tracer.     

我国东南沿海城市地下建筑氡浓度分布

为了解东南沿海城市地下建筑氡浓度的分布，用固体核径迹法(SSNTD’s)，分别在春、夏、冬3季对沿海7城市地下建筑室内氡浓度进行调查。结果表明，福州具有最高的平均氡浓度，上海的平均氡浓度最低。季节的变化对地下建筑室内氡浓度有影响，各城市氡浓度平均值夏季最高、冬季最低。各城市夏季氡浓度与该城市的年均值的比值与城市中各测点氡浓度之间的离散度有一定的相关性。夏季地下建筑室内氡浓度高的城市，它的平均氡浓度受某些具有高氡水平测点的影响大。     

Plutonium use in nuclear power in Russia

Conclusions The following concept of plutonium utilization based on the evolutionary development of the traditional technology in our country arises: The main problem of any short-term program of dealing with plutonium must be solved — reliable and safe storage of separated energy plutonium and freed weapons plutonium before utilization in reactors. Plutonium (mainly energy plutonium) is utilized primarily in BN-800 fast reactors and the development of technology using weapons plutonium in BN-600 reactors starts. In the future attention should be focused on nuclear-power centers patterned after the Industrial Association “Mayak” (RT-1 plant, Complex 300, BN-800) with reliable nonproliferation of weapons plutonium. It is extremely important to speed up work on the completion of Complex 300: This work must be completed before BN-800 is ready. In the future efforts must be concentrated on the following: development and implementation, in BN-800, of an economically more efficient plutonium-burning core; the possibility of building light-water reactors with the required degree of safety for effective plutonium utilization must be justified (including a “cold” core based on cermet fuel); and, development and implementation of technology for a safe and an ecologically acceptable closed nuclear fuel cycle based on plutonium and²³³U with burnout of Am, Np, and Cm. Ministry of Atomic Energy of the Russian Federation. Institute of Physics and Power Engineering. A. A. Bochvar All-Union Scientific-Research Institute of Standardization in Machine Building. Special Design Office for Machines. Translated from Atomnaya énergiya, Vol. 76, No. 4, pp. 326–332, April, 1994.     

秦山核电厂放射源管理经验

秦山核电厂对放射源管理有一套系统的制度，从原的申购，入库，保管，使用，报废，到存入专门的废物库这一全过程实施了严格的控制管理，保证了放射源的安全。本文介绍了秦山核电厂在放射源管理的制度建设，保管使用，监督检查和过程控制等方面的经验。