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桂林、梧州地质环境天然γ放射本底的调查 被引量:1
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作者 林楷 王程强 +1 位作者 李大通 李胜联 《华夏医学》 CAS 2014年第5期36-39,共4页
目的:对桂林市区、梧州市区、临桂县城及永福县城环境天然γ放射本底进行调查,以探讨地质结构与环境天然γ放射本底的关系。方法:分别对梧州市区、桂林市区、临桂县城及永福县城环境天然γ放射本底的流行病学和地质结构进行调查。结果:... 目的:对桂林市区、梧州市区、临桂县城及永福县城环境天然γ放射本底进行调查,以探讨地质结构与环境天然γ放射本底的关系。方法:分别对梧州市区、桂林市区、临桂县城及永福县城环境天然γ放射本底的流行病学和地质结构进行调查。结果:梧州市区环境天然γ放射本底最高,与其他地区比较P<0.05,永福县城环境天然γ放射本底值的变异程度最高,与其他地区比较P<0.0167。结论:作为石灰岩地质结构的地区,桂林具有较低剂量天然γ电离辐射,理应成为人类宜居住的地区。 展开更多
关键词 天然γ放射本底 环境 γ电离辐射
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关于伽玛相机照片图案的编排方式
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作者 张文书 孙秀英 《影像科学与实践》 1994年第2期43-44,共2页
关键词 γ放射照相 核医学 照片 图案编排
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Volumetric fraction measurement in oil-water-gas multiphase flow with dual energy gamma-ray system 被引量:3
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作者 李东晖 吴应湘 +1 位作者 李志彪 钟兴福 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2005年第12期1405-1411,共7页
Volumetric fraction distribution measurement is a constituent part of process tomography system in oil-water-gas multiphase flow. With the technological development of nuclear radial inspection, dual-energy γ-ray tec... Volumetric fraction distribution measurement is a constituent part of process tomography system in oil-water-gas multiphase flow. With the technological development of nuclear radial inspection, dual-energy γ-ray techniques make it possible to investigate the concentration of the different components on the cross-section of oil-water-gas multiphase pipe-flow. The dual-energy gamma-ray technique is based on materials attenuation coefficients measurement comprised of two radioactive isotopes of 241Am and 241Cs which have emission energies at 59.5 keV and 662 keV in this project. Nuclear instruments and data acquisition system were designed to measure the material’s attenuation dose rate and a number of static tests were conducted at the Multiphase Laboratory, Institute of Mechanics, Chinese Academy of Sciences. Three phases of oil-water-gas media were inves- tigated for their possible use to simulate different media volumetric fraction distributions in experimental vessels. Attenuation intensities were measured, and the arithmetic of linear attenuation coefficients and the equations of volumetric fractions were studied. Investigation of an unexpected measurement error from attenuation equations revealed that a modified arithmetic was involved and finally the system achieved acceptable accuracy in experimental research. 展开更多
关键词 Volumetric fraction Multiphase flow Dual-energy γ-ray Process tomography
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Effect of PLA/ZnO Packaging and Gamma Radiation on the Content of Listeria innocua, Escherichia coil and Salmonella enterica on Ham during Storage at 4℃ 被引量:1
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作者 Antonella Marra Aria Boumail +3 位作者 Sossio Cimmino Paula Criado Clara Silvestre Monique Lacroix 《Journal of Food Science and Engineering》 2016年第5期245-259,共15页
The effect of ZnO and low y-radiation on PLA based-films was investigated to be used for food packaging application. Ham slices were inoculated with E. coli, L. innocua and S. enterica and then covered with PLA and PL... The effect of ZnO and low y-radiation on PLA based-films was investigated to be used for food packaging application. Ham slices were inoculated with E. coli, L. innocua and S. enterica and then covered with PLA and PLA/5% ZnO films. The samples were irradiated with a y-radiation dose of 0.3 kGy at dose rate of 13.5 kGy/h. Microbiological analysis was performed at 0, 1 and 5 days on samples stored at 4 ℃. Results showed that no consistent reduction of bacteria was obtained, even at the fifth day of storage, when the ham was covered with PLA/5% ZnO film and no γ-radiation was performed. The use of γ-radiation results necessary to reduce the bacteria growth. In fact E. coli and S. enterica were not detected after 5 days of storage; whereas in the case of test with L. innocua a reduction of 1.3 log CFU/g was observed after 5 days of storage. The antibacterial results indicate that the presence of ZnO in PLA film is effective only for E. coll. The differences of the results obtained here with those reported in literature (where ZnO particles are reported to be very effective as antimicrobial material) are accounted for the different methodologies used. In conclusion considering the positive results, even if small, obtained here at least only for the E. Coli and considering that PLA/5% ZnO film shows, compared to plain PLA film, good tensile properties (especially Young's modulus and stress at yielding) and good permeability (to O2 and CO2) induce to consider the PLA/5% ZnO composite film usable for food packaging when long shelf life and food safety are required, considering also that it is biodegradable and compostable. 展开更多
关键词 Polylactic acid zinc oxide BIOCOMPOSITE food packaging γ-radiation antimicrobial property.
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Study on absorption coefficients of dual-energy γ-rays in determining phase fractions of multiphase flows
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作者 李志彪 李东晖 吴应湘 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2005年第12期1416-1419,共4页
This paper discusses the principle and mathematical method to measure the phase fractions of multiphase flows by using a dual-energy gamma-ray system. The dual-energy gamma-ray device is composed of radioactive isotop... This paper discusses the principle and mathematical method to measure the phase fractions of multiphase flows by using a dual-energy gamma-ray system. The dual-energy gamma-ray device is composed of radioactive isotopes of 241Am and 137Cs with emission energies of 59.5 keV and 662 keV respectively. A rational method to calibrate the absorption coefficient was introduced in detail. The statistical error has been analyzed on the basis of the accurate absorption coefficient which enables determination phrase fractions almost independent of the flow regime. Improvement has been achieved on the measurement accuracy of phase fractions. 展开更多
关键词 Absorption coefficient γ-rays DUAL-ENERGY Phase fraction
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Activity Concentrations and Associated Gamma Doses of 238U and 235U in Jordan
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作者 ABDUL-WALI M. S. AJLOUNI 《Journal of Physical Science and Application》 2015年第5期367-372,共6页
In this study, sixteen soil and vegetable samples from Tafila district were collected and analyzed from eight locations. Measurements of specific activity of natural gamma emitter radionuclides, 23SU and 235U, in thes... In this study, sixteen soil and vegetable samples from Tafila district were collected and analyzed from eight locations. Measurements of specific activity of natural gamma emitter radionuclides, 23SU and 235U, in these samples using gamma spectrometry, with the help of Genie 2000 software. Measurements were used to calculate the soil-vegetable transfer factor, and then the external radiation dose and internal radiation dose due to radioactivity of the ingested food. The specific activity of238U and 235U in soil were found to vary from (in Bq/kg): 26-575 and 1.4-35.5, respectively. The specific activity of 238U and 235U in vegetables were found to vary from (in Bq/kg): 0.019 to 0.632 and 0.0013-0.0375, respectively. The calculated transfer factor of Z3SU and Z35U range from 5.9 × 10^-4to 14.6 × 10^-4 for 238U and 4.9 × 10^-4 to 16.1 × 10^-4 for 235U. External absorbed dose rates were calculated to be in the range from 12.42 to 266.00 nGy/h. The annual effective dose was found to vary from 28.94 to 619.78 μSv/y. The annual internal effective dose due to 23SU and 23SU for fresh weights ofvegetablesl were found to vary from 0.9 × 10^-3 to 35.1 × 10^-3 μSv/y for 238U and 0.61 × 10^-4 to 17.62 × 10^-4 μSv/y for 235U. 展开更多
关键词 SOIL VEGETABLES gamma spectrometry environmental radioactivity Tafila JORDAN transfer factor internal dose external dose.
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Isolation of Uranium by Anionic Exchange Resins
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作者 Fablola Monroy-Guzman 《Journal of Chemistry and Chemical Engineering》 2016年第2期90-95,共6页
A separation methodology to isolate natural uranium from its radioactive daughters: Th, Ra, Bi, Pb, Pa and Po, was developed using an only one anion exchange resin and varying concentrations of HC1 solutions. Three t... A separation methodology to isolate natural uranium from its radioactive daughters: Th, Ra, Bi, Pb, Pa and Po, was developed using an only one anion exchange resin and varying concentrations of HC1 solutions. Three types of anion exchange resins were tested and the separation process was followed by gamma and alpha spectrometry. Uranium can be quantitatively isolated from its descendants using Dowex IX8 (20-50 mesh) or Amerlite IRA (100 mesh) resins in three steps: using 4 and 8 mol/L-1 HCI and water to recover uranium. The method is easy, quick, and inexpensive. 展开更多
关键词 Anion exchange resin URANIUM separation.
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The Effectiveness of Radiation Damage Reduction in Mice by Laser Light in Dependence of the Time Interval between Exposures
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作者 Karine Voskanyan Svetlana Vorozhtsova +2 位作者 Alia Abrosimova Gennady Mitsyn Victor Gaevskiy 《Journal of Physical Science and Application》 2015年第4期291-295,共5页
A research was carried out to determine the period of time during which it is possible to reduce the radiation damage in mice by means of laser radiation (650 nm) after gamma irradiation. First, the mice were expose... A research was carried out to determine the period of time during which it is possible to reduce the radiation damage in mice by means of laser radiation (650 nm) after gamma irradiation. First, the mice were exposed to γ- radiation (whole body irradiation), then after 2 h or 24 h they were irradiated with laser radiation. The results of these studies have shown that the use of laser irradiation to reduce radiation damage in mice is effective 24 h after the exposure to 5 Gy ionizing radiation which leads to the bone-marrow clinical form of the ARS (Acute radiation sickness). In case of the lethal dose of ionizing radiation 7 Gy (the transitional clinical form of the ARS), the increase in life expectancy of mice is observed using laser radiation both 2 and 24 h after the exposure to γ- radiation, but the effectiveness of the laser used 2 h after the ionizing radiation is significantly more efficient. 展开更多
关键词 Gamma radiation laser radiation reduction of the radiation damage.
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Clinical study on gefitinib combined with γ-ray stereotactic radiotherapy for senile patients with adenocarcinoma of lung as the first-line regimen
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作者 Dejian Pan Biao Wang +1 位作者 Xijian Zhou Donglin Wang 《The Chinese-German Journal of Clinical Oncology》 CAS 2011年第7期386-390,共5页
Objective: The aim of our study was to evaluate the efficacy and safety of gefitinib combined with γ-ray stereo-tactic radiotherapy for senile patients with adenocarcinoma of lung as the first-line regimen. Methods: ... Objective: The aim of our study was to evaluate the efficacy and safety of gefitinib combined with γ-ray stereo-tactic radiotherapy for senile patients with adenocarcinoma of lung as the first-line regimen. Methods: The 153 senile patients with adenocarcinoma of lung were divided into 4 groups according to the therapy method. Group A was the 35 patients treated with gefitinib combined with γ-ray stereotactic radiotherapy. Group B was the 45 patients treated with γ-ray stereotactic radio-therapy. Group C was the 42 patients treated with gefitinib. Group D was the 31 patients treated with best supportive therapy. The patients received gefitinib of 250 mg/d from the first day until disease progression or other reasons. The patients were treated with γ-ray stereotactic radiotherapy from the second day. Dose curve of this group of cases was 50%-80%. Encircled dose was 4.0-6.5 Gy per fraction and the range of total dose was 36-48 Gy. The total number of treatment was 8-12 and treated six times every week. Results: All the patients were examined by enhanced double helix CT at the second month. The tumor response rate (RR) of group A was 68.6% (24/35). Disease control rate (DCR) was 88.6% (31/35). The median survival time (MST) was 13.4 months (range 3-34 months ) and the progression-free survival (PFS) was 7.8 months. The overall 1-year survival rate was 40.0% (14/35). The main side effects included skin rash and diarrhea. The RR of group B was 51.1% (23/45). DCR was 71.1% (32/45). MST was 9.6 months (range, 3-18 months ) and PFS was 5.3 months. The overall 1-year survival rate was 15.6 % (7/45). The RR of group C was 40.5 % (17/42). DCR was 61.9% (26 /42). MST was 10.3 months (range, 3-26 months ) and PFS was 5.1 months. The overall 1-year survival rate was 35.7 % (15/42). The main side effects included skin rash and diarrhea. The MST of group D was 5.6 months (range, 2-11 months ) and PFS was 1.7 months. The overall 1-year survival rate was 0. The short-term therapeutic effects (RR) of group A was higher than group C (P = 0.014 < 0.05, χ2 = 6.053) but has no significant difference with group B (P = 0.116 > 0.05, χ2 = 2.477). The long-term therapeutic effects (overall 1-year survival rate) of group A was higher than group B (P = 0.014 < 0.05, χ2 = 6.077) but has no significant difference with group C (P = 0.642 > 0.05, χ2 = 0.216). Conclusion: Gefitinib combined with γ-ray stereotactic radiotherapy is feasible and effective for treatment in senile patients with adenocarcinoma of lung as the first-line regimen. 展开更多
关键词 GEFITINIB γ-ray stereotactic radiotherapy adenocarcinoma of lung SENILE first-line regimen
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Study of the Opuntia ficus indica and Its Radioactive Potassium Content using the Gamma Spectrometry 被引量:1
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作者 Guillermo Espmosa Jose-Ignaclo Golzarri Edgar Padilla-Soriano 《Journal of Environmental Science and Engineering(B)》 2016年第4期167-172,共6页
Mexico is one of the largest producers of nopal (Opuntiaficus indica). This "vegetable" is consumed on a daily basis by the Mexican population, being a source of food nutrients. Among its benefits, it is considere... Mexico is one of the largest producers of nopal (Opuntiaficus indica). This "vegetable" is consumed on a daily basis by the Mexican population, being a source of food nutrients. Among its benefits, it is considered the content of potassium, which is essential for human life and health. In this study, it analyzes the content of potassium of the Mexican cactus (Opuntiaficus indica) grown in 5 different regions in the Mexican Basin, where 67% of the nopal is produced for human consumption. The used methodology is gamma spectrometry with Hyperpure Germanium detector (HPGe) and Multichannel Analyzer (MCA) with Maestro~ software. The results show interesting aspects on the concentration of potassium in the nopal. This concentration will primarily depend on: (a) the geological characteristics of the location where the nopal was grows; (b) that potassium concentrations may vary substantially from a region to another, with the same species of nopal as a reference and (c) that this concentration may also vary from one growing season to another. 展开更多
关键词 POTASSIUM nopal (Opuntiaficus indica) gamma spectrometry K-40 HPGe.
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Gefitinib combined with γ-ray stereotactic body radiation therapy has better efficacy than gefitinib alone for senile lung adenocarcinoma patients with EGFR mutations as first-line regimen
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作者 Dejian Pan Biao Wang +3 位作者 Weibing Wang Yuanwen Wu Xijian Zhou Donglin Wang 《The Chinese-German Journal of Clinical Oncology》 CAS 2014年第7期299-304,共6页
Objective: The senile lung adenocarcinoma patients harboring an activating epidermal growth factor receptor (EGFR) mutation shows good and rapid response to EGFR tyrosine kinase inhibitors (TKIs). Whether gefitin... Objective: The senile lung adenocarcinoma patients harboring an activating epidermal growth factor receptor (EGFR) mutation shows good and rapid response to EGFR tyrosine kinase inhibitors (TKIs). Whether gefitinib combined with y-ray stereotactic body radiation therapy has better efficacy than gefitinib alone for senile lung adenocarcinoma patients with EGFR mutations as first-line regimen is still under investigation. Methods: The 42 senile lung adenocarcinoma patients with EGFR mutations were divided into 2 groups according to the therapy method. Group A was the 22 patients treated with gefitinib combined with y-ray stereotactic body radiation therapy (SBRT). Group B was the 20 patients treated with gefitinib alone. All of the patients received gefitinib of 250 mg/d from the first day until disease progression or other reasons. The patients of Group A were treated with y-ray stereotactic body radiation therapy from the second day. Radiation fields included the primary lesions and the integration of lymph nodes. Dose curve of this group was 50%-80%. Encircled dose was 4.0-6.5 Gy per fraction and the range of total dose was 40-52 Gy. We treated the patients 8-12 times and treated five times every week. Results: All the patients were examined by enhanced double helix CT at the second month. The tumor response rate (RR) of group A was 81.8% (18/22). Disease control rate (DCR) was 90.9% (20/22). The median overall survival (OS) was 24.2 months (range 8-58 months ) and the progression-free survival (PFS) was 18.6 months. The overall 1-year survival rate was 72.3% (16/22) and 2-year survival rate was 54.5% (12/22). The main side effects included skin rash and diarrhea. The RR of group B was 50.0 % (10/20). DCR was 75.0% (15/20). OS was 17.4 months (range 6-32 months ) and PFS was 12.1 months. The overall 1-year survival rate was 60.0% (12/20) and 2-year survival rate was 40.0% (8/20). The main side effects included skin rash and diarrhea. The group A who were treated with gefitinib combined with y-ray stereotactic body radiation therapy had a higher short term therapeutic effects (RR) and long term therapeutic effects (OS) than group B who were treated with gefitinib alone respectively (81.8% vs 50.0%, P = 0.029 〈 0.05, x2 = 4.773 and 24.2 vs 17.4, P = 0.024 〈 0.05, X2 = 5.098). Conclu. sion: Gefitinib combined with y-ray stereotactic body radiation therapy has better efficacy than gefitinib alone for senile lung adenocarcinoma patients with EGFR mutations as first-line regimen. The side affects are acceptable. 展开更多
关键词 GEFITINIB y-ray stereotactic body radiation therapy (SBRT) epidermal growth factor receptor (EGFR) mutations SENILE first-line regimen
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γ辐射和高温对放射性废物水泥固化体强度的影响(英文) 被引量:1
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作者 Bart CRAEYE Geert De SCHUTTER Isabelle GERARDY 《硅酸盐学报》 EI CAS CSCD 北大核心 2012年第1期33-38,共6页
为了处理高活性、放热性C级放射性废弃物,在比利时通常采用圆柱体混凝土"超级容器"作为基本途径。"超级容器"是合成的废弃物包,废弃物由碳钢包裹组成,碳钢被波特兰水泥制成的"缓冲器"包裹。自密实混凝土... 为了处理高活性、放热性C级放射性废弃物,在比利时通常采用圆柱体混凝土"超级容器"作为基本途径。"超级容器"是合成的废弃物包,废弃物由碳钢包裹组成,碳钢被波特兰水泥制成的"缓冲器"包裹。自密实混凝土作为一种特殊类型的混凝土,正被考虑用来制备"缓冲器"。一旦"缓冲器"被浇筑并且硬化程度很高时,放射性废弃物就被包裹在"缓冲器"内,存在的缝隙可以采用新拌灌浆料填充(例如自密实砂浆)。用盖子将"超级容器"密封后应用于"超级容器"的混凝土层,即混凝土缓冲器、灌浆料及盖子在硬化期间(灌浆料)与硬化之后("缓冲器"与盖子)将暴露在废弃物热场与辐射场内。因此,需要解决2个主要的问题:1)γ射线(α与β射线被碳钢包裹层阻断,中子的影响可以忽略)对灌浆料硬化强度的影响;2)温度升高(从20℃升高到105℃)对硬化试件强度的影响。为了证实强度是否损失并确定强度损失后的主要机理,采用荧光显微镜,在砂浆或混凝土薄片的截面上直接分析毛细孔隙率。 展开更多
关键词 γ放射 热荷载 强度 毛细孔隙率
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医用核仪器标准的调查与分析——核仪器标准的制修订、宣贯与实施问题 被引量:1
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作者 范蕙君 《核标准计量与质量》 1994年第2期5-12,共8页
我国医用核仪器的研制是从七十年代起步的,据不完全资料统计,目前至少有30多个单位生产此类仪器。261、262、759厂,核海公司和日环仪器厂是我国生产医用核仪器的几个大厂。目前我国γ放射免疫计数器、放射性活度计、液体闪烁计数器、甲... 我国医用核仪器的研制是从七十年代起步的,据不完全资料统计,目前至少有30多个单位生产此类仪器。261、262、759厂,核海公司和日环仪器厂是我国生产医用核仪器的几个大厂。目前我国γ放射免疫计数器、放射性活度计、液体闪烁计数器、甲功仪、肾功仪、骨密度仪……,已普及到县级医院。γ照相机已能批量生产、单光子发射计算机断层扫描装置已由组装国外散件配自产图像处理机发展到自己研制出样机阶段,形势喜人。 为了使各生产单位在医用核仪器的设计和生产过程中有一个共同遵循的准则,以确保产品的质量,全国核仪器仪表标准化技术委员会组织有关单位和专家制定了EJ298—87《人体甲状腺摄碘率测定仪探头技术要求》、GB/T10255—88《γ放射免疫计数器》、GB10256—88《放射性活度计》、GB/T10259—88《液体闪烁计数系统》和EJ441—89《肾功能仪铅准直探头》等5个标准。 笔者在经过对30余个医用核仪器生产单位和30余个医院的函调,及对261厂、262厂、核海公司、中国计量院等生产单位和协和、肿瘤医院等使用单位的重点走访的基础上撰写了此文,以供今后制修订和贯彻实施标准作参考。 展开更多
关键词 核仪器 液体闪烁计数器 免疫计数器 γ照相机 放射性活度 直探头 γ放射 肾功能仪 中国计量院 甲状腺摄碘率
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