某退役铀矿环境放射性现状调查

介绍了对安徽省某退役铀矿的环境放射性现状调查。调查结果表明：尾渣掩埋坑周围的γ辐射空气吸收剂量率远高于安徽省天然放射性水平调查值,原铀水冶厂遗址处种植的青菜,黄豆中∧238U的含量高出对照占业个量级。土壤样品中的放射性核素∧238U、∧226Ra、∧232Th、∧40K的含量均高于安徽省土壤放射性核素的平均含量,部分采样点的∧226Ra含量超过国家标准。     

非洲西北部晚元古代火山岩中的铀和钍

非洲西北部晚元古代钙-碱性火山岩经受了低程度变质作用,其U和Th含量变化很大。英安岩和流纹岩的U、Th含量比基性岩要高些,尽管U、Th与SiO_2的相关关系不明显,在酸性岩石中,U和Th与K的关系密切,而且基性和大多数中性熔岩中,这两种元素与惰性的不相容的元素如Zr、Nb、La和Ce有相关关系。酸性火山岩与等量新鲜的近代岩石相比,其U和Th含量较低。如低U/K和Th/K比所示,在这些岩石中U和Th的减少也与K有关。U和Th的减少可能与次生作用有关,这表明非洲西北部的酸性火山岩可能是矿床中放射性元素富集的一个重要来源。     

用多元线性回归法计算铀矿样中的U、Ra、Th和K含量

我们用多元线性回归方法计算铀矿样的γ能谱,从而确定了U、Ra、Th和K的含量。和逆矩阵相比,其优点是不需要用纯U、Ra、Th和K标准样来求解响应系数。     

湖南省土壤中天然放射性核素含量调查研究

本文报道湖南省土壤中天然放射性核素含量的调查结果。布点方法与环境陆地γ辐射剂量率调查相同,全省共布25×25km 网格点309个,土类加密点5个,特殊加密点7个,共采集土壤样品321个。土壤样品中天然放射性核素含量的测定采用放化分析方法。调查结果表明,湖南省土壤中~(23(?))U、~(232)Th、~(226)Ra 和~(40)K 含量按样品数的加权均值分别为48.05、54.82、59.36和447.75Bq/kg。零陵地区土壤中~(238)U、~(232)Th 和~(226)Ra 含量最高,郴州地区次之,湘西自治州地区居三。湖南省6类主要土壤中~(40)含量较为接近,而红壤中~(238)U、~(232)Th 和~(226)Ra 含量较高。     

河北省土壤中天然放射性核素含量调查研究

本文报道河北省土壤中天然放射性核素含量调查的方法与结果。基本与环境陆地γ辐射剂量率调查同位布点,全省共采集土壤样品382个,其中25 km×25 km 网格点土壤样品285个。测量采用γ能谱法。调查结果表明,河北省土壤中天然放射性核素含量按面积和按网格点加权的平均值分别为:~(238)U,30.2和30.4 Bq/kg;~(226)Ra,26.9和27.1 Bq/kg;~(232)Th,40.7和41.1 Bq/kg;~(40)K,612.4和613.5 Bq/kg。阜平县“计马石”附近土壤中~(232)Th 含量为247.4B q/kg,明显偏高。     

包头地区土壤中天然放射性核素含量调查

本文报告包头地区土壤中天然放射性核素含量调查结果。本次调查共采集土壤样品151个,样品测定采用γ能谱法。结果表明:包头地区(除包钢地区和白云鄂博矿区之外)98个土壤样品~(238)U的平均含量为25.9Bq/kg(波动范围12.9—83.9Bq/kg);~(232)Th 为37.8Bq/kg(20.3—97.9Bq/kg);~(236)Ra 为25.1Bq/kg(13.1—83.6Bq/kg);~(40)K 为522.4Bg/kg(83.9—1526Bq/kg)。包钢地区和白云鄂博矿区土壤中~(232)Th 含量较高;其余地区土壤中放射性核素含量均为正常水平。     

浙江省土壤中天然放射性核素含量调查

本文报告浙江省土壤中天然放射性核素含量的调查结果。全省共采集土壤样品533个,分析方法采用γ谱法。结果表明:浙江省土壤中天然放射性核素含量随地区、地形、地貌和土壤类型而变,按网格点的平均含量为:~(238)U,46.3Bq/Kg(范围为13.5—123.0B_q/Kg);~(226)Ra,43.4Bq/Kg(17.4—150.2B_q/Kg);~(232)Th,63.0Bq/Kg(26.3—156.5B_q/Kg);~(40)K,771B_q/Kg(118—1603B_q/Kg)。     

三种铝样品中^232Th和^238U的含量

本文介绍了用HPGe反康普顿γ谱仪分析三种铝样品(L4R,Lr11CR,Cz)中天然放射性核素~(232)Th和~(233)U含量的结果,其中~(233)U的含量为0.8—0.52Bq/kg,~(232)Th的含量为2.3—6.8Bq/kg。     

广西壮族自治区土壤中天然放射性核素含量调查研究

本文报道广西壮族自治区土壤中天然放射性核素含量调查的主要结果。基本与环境陆地γ辐射剂量率调查同位布点,全自治区共采集土壤样品383个,其中包括25 km×25 km 网格点样品360个,土壤类型加密点21个,特殊点2个。测量采用γ能谱法。调查结果表明,广西壮族自治区土壤(干样)中天然放射性核素~(238)U、~(226)Ra、~(232)Th、~(40)K 含量按面积加权平均值(±单次测量标准差)分别为:53.0(±32.7)、53.1(±35.2)、69.1(±34.6)和332.2(±234.4)Bq/kg。调查中发现“花山-姑婆山”一带土壤中天然放射性核素含量显著偏高,其土壤中~(238)U、~(226)Ra、~(232)Th、~(40)K 含量分别为170、184、211、766Bq/kg。     

矿物中铀、钍、金、钪的堆中子活化分析

中子活化分析具有灵敏度高、选择性好、用样量少、不破坏分析样品,且可进行多元素同时测定等优点,因此适于岩矿样品的分析。 我们利用原子能所实验性重水型反应堆进行辐照,用美国CANBERRA公司生产的SCORPIO-3000系列多道计算机系统,用仪器中子活化分析法测定了岩矿中的铀、钍、金、钪的含量,得到较为满意的结果。 一、实验1.仪器和设备体积为96厘米3的同轴Ge(Li)半导体探测器和4096道脉冲幅度分析器组成的γ谱仪,     

Stopping powers of Be,Al, Ti,V, Fe,Co, Ni,Cu, Zn,Mo, Rh,Ag, Sn,Ta, Pt and Au For 6.5 MeV protons

The stopping powers of Be, Al, Ti, V, Fe, Co, Ni, Cu, Zn, Mo, Rh, Ag, Sn, Ta, Pt and Au for 6.5 MeV have been measured using a surface barrier silicon detector. The accuracy of the results is ± 0.3%. The detail of the experimental procedures is described. The results have been compared with the Risø data and the Aarhus data of Andersen et al. The present results for Al, Cu and Ag agree very well with the Aarhus results at 6.5 MeV. The mean excitation energy has been extracted from the present results using the Bonderup shell correction, the Barkas correction and the Bloch correction. The parameters x and b which appear in the Bonderup shell correction and the Barkas correction have been newly determined as x = 1.358 and b = 1.3. The present mean excitation energy agrees very well with the I values obtained by other authors. It has been confirmed that the Bonderup shell correction is quantitatively correct for 6.5 MeV protons.     

Wavelengths,transition probabilities,and oscillator strengths for M-shell transitions in Co-, Ni-, Cu-, Zn-, Ga-, Ge-, and Se-like Au ions

Wavelengths, transition probabilities, and oscillator strengths have been calculated for M-shell electric dipole transitions in Co-, Ni-, Cu-, Zn-, Ga-, Ge-, and Se-like Au ions. The fully relativistic multiconfiguration Dirac–Fock method, taking quantum electrodynamical effects and the Breit correction into account, was used in the calculations. Calculated energy levels of M-shell excited states for Cu-, Zn-, Ga-, Ge-, and Se-like Au ions from the method were compared with available theoretical and experimental results, and good agreement with them was achieved.     

Measurements of the total effective cross sections for resonance neutrons in Pd,Os, Ir,Mo, In,I, Ta,Th, U238

The results of calculations of the level constants in the elements Pd, Os, Ir, Mo, I, In, Ta, Th, U²³⁸ are presented; the cross sections for these elements have been published earlier. New measurements for the cross sections in Ir, Th, U²³⁸ are cited. The measurements were made with a mechanical-chopper spectrometer with a resolution of 0.08 sec/m in the energy region from 4.5 to 10,000 ev. The integrated and differential curves for the distribution of neutron widths in these elements are plotted.Presented at the International Conference on Nuclear Reactions in Amsterdam (June 1956).The authors take this opportunity to express their gratitude to U. Chi-Kwa and Suan Chi-Ling for their assistance in the mathematical analysis of the experimental results, G. M. Kukavadze for the mass-spectro-graphic analyses of the samples, V. N. Bovinoi and M. P. Anikinoi for providing the chemical analyses and A. I. Ermakov, N. S. Rezvyakov, G. V. Rukolaine and K. A. Trostinoi for help in building the analyzer and in carrying out the measurements.     

Discovery of dysprosium,holmium, erbium,thulium, and ytterbium isotopes

Currently, thirty-one dysprosium, thirty-two holmium, thirty-two erbium, thirty-three thulium, and thirty-one ytterbium isotopes have been observed and the discovery of these isotopes is described here. For each isotope a brief synopsis of the first refereed publication, including the production and identification method, is presented.