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中子活化分析对河南南阳独山玉的研究 总被引:3,自引:0,他引:3
应用中子活化分析法对河南南阳独山玉的稀土微量元素进行了研究 ,结果表明 :白独玉、绿独玉与黑独玉的地球化学特征有明显的差别。其中 ,它们每种玉的平均值 :8个稀土总量 (8∑REE)分别为 1.4 5、6 .895、3.86 7μg·g- 1;全线斜率 (La/Yb)分别为 14 .2 77、4 .936、0 .84 9μg·g- 1;微量元素Sr分别为 75 4、4 34、115 μg·g- 1,Cr分别为 5 .5 3、10 95、85 1μg·g- 1,Fe分别为 2 777、2 838、2 875 0 μg·g- 1,Mn分别为 6 8、6 5 .5、5 32 μg·g- 1;绿独玉正Eu异常最大 ,而黑独玉的正Eu异常最小。这些特征可作为鉴别独山玉的地球化学标志 ,对考古及古玉的深入研究与鉴别具有重要意义。 相似文献
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玉华山火山盆地铀矿床为山—筒山断裂带控矿特征 总被引:1,自引:0,他引:1
在简述玉华山地区地质背景的基础上,阐明为山—筒山断裂带地质特征,分析其对铀矿控制特点,总结铀矿化富集规律。认为为山—筒山断裂带不仅是玉华山火山盆地控岩构造,而且是重要的控矿、导矿和容矿构造。控矿构造可划分为:主构造对矿化的控制、旁侧次级构造对矿化的控制和主构造与岩性组合对矿化的控制3种形式。铀矿化富集一方面与断裂构造发育程度有关;另一方面与断裂构造充填物关系密切,特别是与充填于断裂带中花岗斑岩形态及产状变化密切相关。今后玉华山地区铀矿找矿工作,可把控矿构造作为主要研究目标。 相似文献
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文章对核电厂安全级连续工作制电动机的鉴定目标、服役环境条件、鉴定寿命、老化分析、设计基准事件模拟试验、状态监测等鉴定要素进行了系统化阐述,并对鉴定方法和鉴定程序进行了总结,可以为鉴定单位编制具体的安全级连续工作制电动机鉴定规程和开展具体的鉴定活动提供有效指导。 相似文献
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本文首先从法规层面指出实施大型钠冷快堆设备鉴定的必要性;其次,通过鉴定标准、设备特点、环境条件、鉴定技术以及试验设施等方面的对比,阐述了大型钠冷快堆与压水堆设备鉴定之间的差异性;针对两者存在的差异性,以及中国实验快堆建设过程中设备鉴定技术积累的有限性,从鉴定标准体系建立、钠环境设备失效机理研究、大型堆容器抗震试验研究、钠环境试验设施研究以及大型钠冷快堆设备鉴定数据库建构等方面进行了分析,并给出了建议。 相似文献
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Hasan M. KHAN Ijaz A. BHATTI 《核技术(英文版)》2007,18(1):26-29
Food irradiation is gaining popularity worldwide and this technology is important to improve quality and reduce the post harvest losses of food. Because of the rapid commercialization of irradiated foods throughout the world, compliance of different regulations relating to use of technology in different countries and demand of consumers for clear labelling of irradiated foods, there is need for the development of analytical methods to detect radiation treatment of food. Among several methods studied so far, thermoluminescence (TL) is an important method that can be used to find out the irradiation history of food that contain even a very minute amount of dust particles. In this study, the irradiated and unirradiated wheat and rice samples were analyzed using the TL method. The samples were purchased from the local market of Peshawar and irradiated to radiation doses of 0.5 and 1.0 kGy using Co-60 gamma irradiator at the Nuclear Institute for Food and Agriculture (NIFA), Peshawar. The mineral contaminants were isolated by jet water, ultrasonic treatment, and density gradient. TL glow curves of the isolated minerals from irradiated and unirradiated samples were recorded between the temperature ranges of 50-500℃ using a TL reader. Generally, the glow curves for irradiated samples showed much higher TL intensities (TL1) than the unirradiated samples. The results were normalized by rerradiation of mineral samples to gamma-ray dose of 1.0 kGy followed by determination of the second glow curves (TL2). The ratio of the area of first glow curve to that of second glow curve (TL1/TL2) was calculated for selected temperature intervals and compared with the recommended values for unirradiated and irradiated samples. Finally, the shapes of the glow curves for irradiated and unirradiated samples were also analyzed. On the basis of these results (comparison of TL-intensities, TL1/TL2 ratios and shapes of the glow curves), all the irradiated and unirradiated samples of wheat and rice were unequivocally identified. 相似文献
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糖尿病性阳痿患者性激素受体变化研究 总被引:1,自引:0,他引:1
为探讨性激素和性激素受体与糖尿病性阳瘘的关系,选择32例糖尿病性阳瘘患者、32例糠尿病无阳瘘患者、32例非糖尿病阳瘘患者和40例健康男性为研究对象,分别采用放射免疫分析测定血浆PRL、T、E2水平,采用放射配基结合分析测定外周血白细胞的ER、AR水平。结果显示,与正常对照组和非糖尿病性阳瘘组相比,糖尿病性阳瘘组和糖尿病无阳瘘组的PRL水平均升高,T和R水平均降低,E2/T和ER/AR比值均升高;与糖尿病无阳瘘组相比,糖尿病性阳瘘组的PRL水平、T水平、E2/T比值均无显著差异,但AR水平进一步降低,ER/AR比值进一步升高。T和AR水平均与年龄之间存在负相关关系。AR水平降低和ER/AR比值升高可能是导致糖尿病性阳瘘的重要原因之一;T和AR水平随年龄增长而降低可能是导致糖尿病性阳瘘的发病率随年龄增长而明显增加的重要原因。 相似文献
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Surface and structural damage to plasma-facing components due to the frequent loss of plasma confinement remains a serious problem for the tokamak reactor concept. The deposited plasma energy during major disruptions, edge-localized modes (ELMs), and vertical displacement events (VDEs) causes significant surface erosion, possible structural failure, and frequent plasma contamination. Surface damage consists of vaporization, spallation, and liquid splatter of metallic materials. Structural damage includes large temperature increases and high thermal stresses in structural materials and at the interfaces between surface coatings and structural members. To evaluate the lifetimes of plasma-facing materials and nearby components and to predict the various forms of damage that they experience, comprehensive models (contained in the
computer simulation package) are developed, integrated self-consistently, and enhanced. Splashing mechanisms such as bubble boiling and various liquid magnetohydrodynamic (MHD) instabilities and brittle destruction mechanisms of nonmelting materials can be serious erosion mechanisms and are being studied in detail. The ejected macroscopic particles (MPs) will interact with incoming plasma particles and with the vapor cloud above the surface. Therefore, the dynamic behavior of MPs in the vapor cloud and their influence on total erosion rate is important. Results of self-consistent MHD calculations are presented in which the dynamics of both the vapor cloud and MP interaction are coupled with incoming plasma ions and electrons from the scrape-off layer during a disruption. The design requirements and implications of plasma facing and nearby components are discussed, along with recommendations to mitigate and reduce the effects of plasma instabilities on reactor components. 相似文献
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工业管道在长时间使用过程中,会积聚杂质影响产能,所以需要进行管道清洗。管道清洗装置依次接入工业管路中,清洗各管道杂质。为实时监测管道清洗装置的各项参数,实现人机交互,研制了一套自控系统。该系统选择泓格控制器、研华一体机配合LabVIEW的软硬件架构,缩短系统开发时间,实现系统小型化;采用“双背板”结构、快接插件设计,满足结构的小型化以及快速拆装要求;设计自动关断电动阀,发生紧急情况时,实现与设备的快速截断隔离以防止破空,增强整个系统的安全防护。该自控系统实现了工艺参数的监测、控制、报警、存储、查询、数据导出等功能,拆装方便、可移动,可满足现场的使用要求,同时保障了设备的稳定运行。目前该自控系统已正式投入使用,运行安全稳定。 相似文献
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合成了水溶性的2,6-二[1-(羟丙基)-1H-1,2,3-三唑-4-基]吡啶(PTD),研究了以N,N,N′,N′-四辛基-3-氧杂戊二酰胺(TODGA)为萃取剂、正十二烷为稀释剂时,PTD对Am和Eu的反萃行为。研究了两相接触时间、PTD浓度、初始硝酸浓度和温度对Am和Eu分配比的影响。结果表明:Am与PTD形成1∶1型和1∶2型配合物,Eu与PTD形成1∶1型配合物; PTD反萃TODGA-TBP中Am和Eu的反应均为吸热过程。在PTD浓度一定的情况下,反萃硝酸浓度小于07 mol/L时,PTD可以实现TODGA中的Am与Eu的反萃分离。 相似文献
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中国散裂中子源是我国正在运行的质子加速器大科学实验装置,保证其空气活化水平处于可监测、可控状态,对确保装置的正常运行和科研产出、确保工作人员和公众的辐射安全具有重要意义。国内外以往对加速器空气活化的认识基本都来自参考文献和理论计算;由于没有针对性研发,以往国内加速器的空气活化监测没有测量到空气活化核素及其浓度。2019年底,散裂中子源研发了在线空气活化监测系统,成功监测到了空气活化的主要放射性核素及其活度浓度。本文介绍了该系统的研发情况和监测结果,并提出了对加速器空气活化监测与评价的一些看法。 相似文献