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11.
We obtained analytical expressions for the intensities of γ-quanta fluxes that were emitted by radioactive isotopes distributed
in soil and that experiented n-tuple scattering. We present these expressions in the form of a sum of multiple integrals of
simple form. The results of numerical integration performed for test examples are given.
Scientific-Research Institute of Nuclear Problems at the Belarusian State University, 11, Bobruiskaya St., 220050, Minsk,
Belarus. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 64, No. 3, pp. 405–411, May–June, 1997. 相似文献
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S. U. El-Kameesy 《Isotopes in environmental and health studies》2013,49(2):269-273
Radioactive contamination in air dust particles of Cairo atmosphere from the Fukushima accident was detected by the gamma-ray spectroscopy technique. Analysis of the spectra obtained by using an High-Purity Germanium detector showed that there were some traces of 131I and 134, 137Cs. Estimate and study of concentration of those radionuclides were done over a period of about 5 months after the accident. Comparison with corresponding results in different countries all over the world has been performed. 相似文献
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Murat Belivermis Önder Kılıç Yavuz Çotuk Sayhan Topçuoğlu Mahmut Coşkun Akın Çayır 《辐射效应与固体损伤》2013,168(11):903-913
The activity concentrations of gamma emitting radionuclides were measured in surface soil samples from the Thrace region. 232Th, 238U, 226Ra, 40K and 137Cs activities and physico-chemical parameters of the soil samples were determined in samples collected from 73 sampling stations. Radionuclide concentrations measured were compared with those found in the samples from other locations of Turkey and from different countries. The average activity concentrations of 232Th, 238U, 226Ra, 40K and 137Cs were found to be 24.71 ± 8.79, 22.30 ± 7.93, 32.09±12.44, 509.00±160.05, 32.74±29.24 Bq kg?1, respectively. The mean value of the annual effective dose equivalent from the outdoor terrestrial gamma radiation was calculated as 57.2 μ Sv. 相似文献
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为分析核事故时东部不同地区放射性核素大气扩散特征的差异性,通过利用区域尺度天气预报模式WRF和高斯大气扩散模式研究了东部区域尺度以及部分核电厂周边的大气弥散因子分布特征。结果表明:东部区域尺度计算网格中心点周边500 m和5000 m处大气弥散因子的最大值分别为10-3 s·m-3量级和10-4 s·m-3量级;不同核电厂距离中心点500 m处的大气弥散因子最大值在10-4 s·m-3量级,距离区域中心点5000 m处的大气弥散因子最大值在10-6~10-4 s·m-3量级之间;针对不同核电厂距离中心点500 m处和5000 m处大气弥散因子比较发现,前者昌江核电厂大气弥散因子最大值最高;后者秦山核电厂大气弥散因子最大值最高。可见不同地区的核电厂受气象场影响其大气扩散特征存在差异。 相似文献
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In this study, the radioactive concentrations contained in samples of commonly used building floor materials were measured. This result can be used as basic information for public health and the environment. Among building floor materials, samples of induction blocks, cement bricks, artificial granite blocks and compact high-pressure blocks were chosen and used. A detailed gamma nuclide analysis was performed with a multichannel analyzer by putting these samples on a high-purity germanium detector which is a semiconductor detector. In order to measure the concentration of radionuclides, a spectrum file was obtained by analyzing the concentration of gamma radionuclides and setting the measurement time as 1000, 4000, 7000 and 10,000?s. According to the study results, K-40, Bi-214, Pb-214, Ra-226 and U-235 were detected in the induction blocks measured at 10,000?s and K-40, Th-230, Bi-214, Pb-214, Ra-226 and Na-22 were detected in the cement bricks measured at 10,000?s. K-40, Bi-214, Pb-214, Th-234, U-235 and Ra-223 were detected in the artificial granite blocks measured at 10,000?s and K-40, Bi-214, Pb-214, Th-234, Ra-226, Ra-223 and Mn-54 were detected in the compact high-pressure blocks. In conclusion, low-level radioactivity was detected in building floor materials, so it is thought that measures to reduce radioactivity and further studies on this will be needed. 相似文献
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Fatma Arslan Martin Behrendt Werner Ernst Eberhard Finckh Gunther Greb Friedrich Gumbmann Martin Haller Stefan Hofmann Ralf Karschnick Matthias Klein Wolfgang Kretschmer Jochen Mackiol Gerhard Morgenroth Christian Pagels Markus Schleicher 《Angewandte Chemie (International ed. in English)》1995,34(2):183-186
19.
利用各种分析手段对膨润土的物理特性进行了表征.X射线衍射分析表明钠基膨润土呈典型的六方晶胞,晶胞参数是: a轴4.913, c轴5.405;差热分析曲线在低温区和高温区有明显的吸热峰出现;元素分析钠、钾离子的含量大于钙、镁离子的含量,在性能上表现为钠质膨润土具有较强的离子交换能力;显微分析表明其表面呈皱隙状,测定比表面积高达24.52 m2/g;吸水率测定表明膨胀率大,说明它具有密封功能,可有效阻滞地下水的渗入.利用SF6示踪技术,通过采集不同时间段取样池样品,分析样品中示踪气体浓度,绘制取样池示踪气体浓度随时间的变化关系曲线,根据费克扩散定律计算扩散系数.实验结果表明,随着压实膨润土密度的增大,示踪气体扩散系数迅速减小,当密度大于1.8 g/cm3时,扩散系数降至10-9 m2/s.研究结果表明,膨润土性能优化是通过在膨润土中添加适量的活性炭,可明显改善其对气体的阻滞能力;增加其对放射性气体滞留能力;添加少量的石英砂增加其机械性能、导热性和减少蠕变性,将引起对气体阻滞能力的下降.综合考虑,在膨润土中各添加5%活性炭和石英砂,既对气体具有较好的滞留能力,又具有较好的工程特性. 相似文献
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V. Hanušik A. Mitro Š. Niedel B. Grošiková E. Uvirová I. Stráňai 《Isotopes in environmental and health studies》2013,49(7):335-338
The paper discribes the computer code POTRE and the auxiliary database system which allow to assess the radiation exposure from ingestion of foodstuffs contaminated by radionuclides released from a nuclear facility during normal operation into the atmosphere. 相似文献