共查询到19条相似文献,搜索用时 640 毫秒
1.
2.
3.
4.
一、引言营养卫生学的研究中,痕量元素日益受到人们的重视。为了保证人体对于15种必需痕量元素的补充以及保证毒性元素的摄入在允许剂量之内,从痕量元素含量角度来研究食品和饮料的质量是很重要的。PIXE提供了多种痕量元素含量的同时测定方法。啤酒中微量元素很丰富。啤酒的颜色,芳香,味道和储存质量都和所含微量元素的浓度有关。 相似文献
5.
质子非卢瑟福背散射测量气溶胶样品中氢、碳、氮和氧的含量 总被引:2,自引:1,他引:2
气溶胶样品中Z>12以上元素含量的质子荧光(PIXE)分析是北京师范大学GIC4117串列加速器的主要应用领域之一。为弥补PIXE无法分析H、C、N和O等轻元素之不足,在PIXE靶室160°散射角安装金硅面垒探测器,用质子非卢瑟福背散射分析(PNBS)方法对核孔膜采集的气溶胶样品中H、C、N和O等轻元素的含量进行测量。测量得到的气溶胶样品中H和Si元素含量与质子前角散射(PESA)和PIXE的分析结果相近,表明PNBS可用于核孔膜采集的气溶胶样品的分析。 相似文献
6.
为了确定PIXE(质子X荧光分析)的测量准确性,进行了三个实验室的横向比对分析。比对中使用了30个单元素样品和一个多元素样品。结果显示,对于绝大多数样品,三家的一致性好于10%,三次测量的重复性相对于平均值好于6%。用一个自动的时间顺序步进采样器在北京采集了大气气溶胶样品,用PIXE对这些样品进行元素分析,然后对元素浓度数据用绝对主因子分析(APFA)进行统计分析,求出主成分以及它们解释的百分数。结果表明,PIXE与统计方法相结合可以有效地分解出城市大气气溶胶的主成分,并能将该地的和远地来的成分区别开来。用一个八级撞击式采样器在四个有代表性的地区进行了大气气溶胶采样,从由PIXE分析得到的一些代表性元素浓度的粒径分布特征,推断出大气气溶胶的来源。 相似文献
7.
江西湖田窑明代青花瓷的PIXE研究 总被引:3,自引:0,他引:3
用现代科学技术对中国古瓷的产地、年代和真伪进行研究一直是文博界和科技界研究的热点.本工作采用质子激发X射线发射(PIXE)分析方法研究了江西湖田窑明代中晚期青花瓷的胎、釉和青花中主量、微量元素的含量,并用质子扫描微探针(SPM)分析了青花瓷剖面的元素分布.结果表明元素在古瓷的釉、胎和青花中的分布都是均匀的;胎与青花之间有5~10 μm的中间层,青花与白釉之间无明显的分界线;制作青花的钴料可能产于江西、福建等地. 相似文献
8.
9.
10.
了确定PIXE(质子X荧光分析)的测量准确性,进行了三个实验室的横向比对分析。比对中使用了30个单元素样品和一个多元素样品。结果显示,对于绝大多数样品,三家的致性好于10%,三次测量的重复性相对于平均值好于6%。用一个自动的时间顺序步进采样器在北京采集了大气气溶胶样品,用PIXE对这些样品进行元素分析,然后对元素浓 相似文献
11.
补碘和硒对克汀鼠红血球中的微量元素的影响 总被引:2,自引:0,他引:2
用克汀病流行病区的粮食喂养大鼠(克汀鼠),分成4个组补硒、补碘、补碘同时补硒、和作为对照的低碘鼠,另取一正常对照组。补充5周后,用PIXE法和测量它们红血球的微量元素(K、Ca、Mn、Fe、Cr、Cu、Zn、Rb、Pb等)。用放射性免疫法测定甲状腺激素指标(T3、T4、FT3、FT4、rT3等)。获得的数据用SPSS/PC单因素方差分析和相关检验。结果表明,低碘鼠补碘、硒或同时补碘硒后,Zn、Mn、Cu和Rb的含量变化以及甲状腺激素指标T4、FT4和rT3比低碘鼠显著地升高。 相似文献
12.
The concentrations of Ti and Ca, P, K, Fe, Cu and Zn in blood samples were determined by PIXE after a single intravenous and a single oral dosing with titanium- ascorbate (Ti- Vc) in Wister rats. Following the intravenous injection with 50 mg Ti- Vc/kg body weight, the absorption, distribution and clearance in blood could be described by an exponential equation of three terms. After gavaged with 500 mg Ti-Vc/kg body weight, at 1.5 h the content of Ti reached the highest level. The concentration of Ca was increasing, with the absorption, distribution and clearance of Ti in blood. The contents of Fe and K were decreasing. And the contents of Cu and Zn were significantly fluctuating. The effect of Ti on animal growth could be explained by the fact that Ti- Vc supplementation could promote the absorption of Ca. 相似文献
13.
T.R. Rautray V. Vijayan M. Sudarshan S. Panigrahi 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》2009,267(17):2878-2883
Particle induced X-ray emission, particle induced γ-ray emission studies has been carried out to analyse normal and carcinoma tissues and blood samples of gallbladder of both sexes and seventeen trace elements namely Na, Mg, Al, K, Ca, Ti, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Br and Pb were estimated in the tissue and blood samples. In the present study, concentration of Zn in the carcinoma gallbladder tissue is less than that of the normal gallbladder tissue. Tobacco habit could be one of the important factors to decrease the elemental concentrations in blood and tissue samples. 相似文献
14.
15.
Wilson‘s病人和正常人发,粪便中微量元素的中子活化分析 总被引:3,自引:0,他引:3
用NAA方法测定人发和粪便样品中Cu、Zn、Ca、Mn、Al和Mg等六种微量元素,分析比较了病人和正常人样品中微量元素含量的差异。并对病人治疗前后微量元素的变化进行了探讨。 相似文献
16.
Brain trace elements and aging 总被引:1,自引:0,他引:1
Geert Hebbrecht Willy Maenhaut Jacques De Reuck 《Nuclear instruments & methods in physics research. Section B, Beam interactions with materials and atoms》1999,150(1-4):208-213
Degenerative mechanisms involved in the aging process of the brain are to a certain extent counteracted by repair mechanisms. In both degenerative and recovery processes, trace elements are involved. The present study focused on the role of two minor (i.e., K and Ca) and six trace elements (i.e., Mn, Fe, Cu, Zn, Se and Rb) in the aging process. The elements were determined by PIXE in cerebral cortex and white matter, basal ganglia, brainstem and cerebellar cortex of 18 postmortem human brains, from persons without a history of neurologic or psychiatric disease who deceased between the age of 7 and 79. This age range allowed us to study the relationship between elemental concentrations and age. The most prominent findings were a concentration decrease for K and Rb and a concentration increase for the elements Ca, Fe, Zn and Se. The study supports recent findings that Ca and Fe are involved in brain degenerative processes initiated by oxygen free radicals, whereas Zn and Se are involved in immunological reactions counteracting the aging process. 相似文献
17.
18.
眼晶体中某些元素含量与白内障关系的研究 总被引:5,自引:0,他引:5
用中子活化分析法测定了正常人眼晶体及老年性白内障晶体中的K、Ca、Na、CI、S、Se、Zn、Mg、Fe、Rb、Cs、Cr、Co、Ce、Mn、Sb、Sc、Eu和Th等19种元素的含量,发现在白内障晶体中Ca、Na、Cl、Eu、Sb、Fe等元素含量显著高于正常晶体;K、Rb、Cs、Cr、Mn、Co、Sc和Ce等元素含量显著低于正常晶体。其中Na、Cl、Ca之间;K、Rb、Cs之间存在显著性正相关。N 相似文献
19.