中子活化分析法测定硒酵母中硒含量

一、前 言 已有的大量研究证明,微量元素硒能降低癌症的发病率,改善心脏病状况,预防克山病,治愈大骨节病。目前,用于临床及营养补充的含硒药物有亚硒酸钠、硒代蛋氨酸和硒酵母。由于无机的亚硒酸钠可能导致毒性,国外一般倾向于用硒蛋氨酸和硒酵母作为人体硒的营养补充。在我国,营养学专家也多次建议用硒酵母作为防癌营养剂,用硒酵母代替治疗克山病的亚硒酸钠。 测定生物样品中硒含量目前最常用的方法是用荧光光度法、无火焰原子吸收法以及中子活化分析法。由于前两种方法均要进行样品前处理,所以对于粉末状的硒酵母很不适宜;相比之下,用中子活化分析法测定硒酵母中硒含量则具有快速、准确等优点。 我们在特定条件下培养出含硒丰富的硒酵母,并首次采用短照中子活化法测定了硒酵母中硒含量且得到了满意的结果。     

DISTRIBUTION OF SOME ELEMENTS IN HUMAN HAIR AND ORGANS DETERMINED BY NAA

Twenty four male autopsies were obtained from Shanghai. The samples of liver, lung, kidney cortex, brain and scalp hair were collected from the autopsies. The elements As, Br, Ca, Cd, Cl, Co, Cr, Cu, Fe, Hg, Mg, Mn, Na, Rb, 8, Se and Zn were determined by neutron activation analysis (NAA). The present study provides the elemental levels of different tissues for normal male adults. The distribution pattern of elements was discussed. Great difference on distribution of some elements in different tissues was observed.     

分子活化分析法研究地质样品中铂族元素的化学种态

用化学逐级溶解、镍流火试金项富集及中子活化分析法研究了中国东部大陆地幔橄榄岩捕掳体中铂族元素的化学种态。分析结果表明，6个物相中单个铂族元素的质量分数加和与铂话元素总量分析结果基本相符；硫化物相中铂话元素分布特征的研究，进一步说明了硫化物的熔出是部分熔融过程中地幔橄榄岩铂族元素分异的重要机制之一。     

中子活化分析法测定巴彦淖尔盟地区环境水中As的种态及微量元素

用萃取－共沉淀法和中子活化分析法联合测定了水中总砷、Ａｓ（Ⅲ）和Ａｓ（Ⅴ）的质量浓度。验证了方法的精密度和准确度。给出了方法的最低探测限：０．０２μｇ／Ｌ。用该方法测定了巴彦淖尔盟地区环境水中Ａｓ的种态和微量元素。分析了地砷病与水中砷的质量浓度的关系。     

STUDY ON Fe ION DISTRIBUTION IN NATURAL CHROMITE BY MOSSBAUER TECHNIQUE

Mossbauer absorption spectra in a natural chromite from Shanxi province of China were measured, covering a temperature range from 12 K to 800 K. Each spectrum at low temperature can be fitted to three doublets: the first two are attributed to tetrahedral T-site Fe ions and the third one to octahedral M-site Fe ions. Such assignment was confirmed by the detailed analyses of the temperature dependent centre shift and other parameters. As a main result, our data strongly supported the ordered distribution with Fe2+ in T-site and Fe3+ in M-site for chromite studied. No evidence for electron hopping processes was detected.     

THE METABOLISM OF TITANIUM AND OTHER ELEMENTS IN WISTER RATS

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.     

中子活化法研究砷中毒病区人发中微量元素的分布

应用中子活化分析法测定了地方性砷中毒病区病人头发中23种微量元素的质量分数,并与北京健康人发中微量元素的质量分数进行了比较。结果表明:As,Fe,REE,Ba,Br,Sb在重病患者发中的质量分数最高,轻病患者次之,正常人最低;而Se,Ca在健康人发中的质量分数最高。用t检验方法比较这三组之间人发中微量元素的差异,发现上述元素在三组中,人发之间均存在明显差异(P<0 05或P<0 001)。并且头发中As质量分数越高,病人病情越严重。Fe,REE和Ba等微量元素可能加重砷的中毒,而Se,Ca和Co可能拮抗砷的毒性。     

STUDY ON OCCURENCE FORM OF PLATINUM IN XINJIE Cu－Pt DEPOSIT BY NAA AND SCANNING PROTON MICROPROBE

ＳＴＵＤＹＯＮＯＣＣＵＲＥＮＣＥＦＯＲＭＯＦＰＬＡＴＩＮＵＭＩＮＸＩＮＪＩＥＣｕ－ＰｔＤＥＰＯＳＩＴＢＹＮＡＡＡＮＤＳＣＡＮＮＩＮＧＰＲＯＴＯＮＭＩＣＲＯＰＲＯＢＥＬｉＸｉａｏｌｉｎ，ＺｈｕＪｉｅｑｉｎｇ，ＧｕＹｉｎｇｍｅｉ，ｗｕＸｉａｎＫａｎｇ（Ｓ...     

用同位素示踪技术研究大鼠体内铬的赋存状态

以富集稳定同位素５０Ｃｒ３＋ 作示踪剂,用Ｓｅｐｈａｄｅｘ Ｇ－２５ 凝胶色谱法和中子活化法研究了Ｃｒ（Ⅲ）在正常和患糖尿病大鼠肝胞液、血清及尿液中的赋存状态。研究发现：（１） Ｃｒ（Ⅲ）在大鼠血清中可迅速与血清蛋白结合,以某种特定蛋白质为载体将Ｃｒ（Ⅲ）运送到身体各部;在大鼠肝胞液中,铬主要与高分子量蛋白质结合,并可能以高分子量铬结合蛋白的形式储存在肝脏中。（２） 在两组大鼠的血清、肝胞液及尿液中均发现有一低分子量（＜ ５ ０００ Ｄ）的铬结合物质存在。（３） 糖尿病大鼠尿中低分子量铬配合物的排泄总量远高于正常组大鼠,这可能是造成糖尿病大鼠体内缺铬的原因之一。     

离子交换色层法分离铀同位素的实验研究

本文利用色带迁移法研究了树脂交联度、树脂粒度、树脂床温度、带迁移速度(流速)、以及推移剂的性质与组成等因素对铀同位素分离的影响,给出了铀同位素分离的较佳条件,得到了比以往U(Ⅵ)络合物体系较好的分离结果,并对结果进行了一定的讨论。     

新疆瓜果辐射贮藏研究

本文描述了1976～1981年新疆瓜果贮藏研究的主要结果。在这一期间,我们研究了2MeV电子静电加速器产生的X射线,β射线以及空气负离子对于新疆无核葡萄,哈密瓜和库尔勒香梨的贮藏效果。这些实验表示结果如下:无核葡萄经过空气负离子处理,其贮藏效果比X射线或β射线处理都好;哈密瓜经过低剂量β射线辐照,贮藏时间延长,保存率提高;库尔勒香梨用空气负离子处理,保存九个月后的保存率为91.9％,同时色香味及外形均未发生大的变化。     

CHEMICAL SPECIES OF IRIDIUM AND OTHER TRACE ELEMENTS IN THE CRETACEOUS-TERTIARY BOUNDARY CLAYS AND ITS IMPLICATION

The geological samples: Cretaceous- Tertiary (K- T) boundary clays, meteorites, volcanic lava, and ultrabasic rock were separated into carbonate, metal, sulfide, oxide, silicate and acid- resistant residue by a selective chemical dissolution procedure developed in our laboratory. Some conclusions were drawn by analyzing the chemical speciation of anomalous iridium in the above samples and especially by studying the characteristics of mineral components in those residue phases. (1) It is impossible that the anomalous Ir was caused by geochemical enrichment; (2) The iridium enrichment in the K- T boundaries did not necessarily associate with kerogen; (3) The volcano activity has participated in the extinction event at the end of Cretaceous; (4) Extraterrestrial impact was the trigger of K- T event. Then, we proposed a mixed model by which the extant anomalous Ir in K- T boundary clays was interpreted as a combined effect of extraterrestrial impact, volcano eruption and post- depositional redistribution.     

氚的生物学效应研究进展

本文综述了最近发表的有关氚对哺乳动物的生物效应的文献资料,其中包括整体和细胞的致死效应,诱发肿瘤和细胞恶性转化,平均寿命缩短,造血功能的改变,生殖细胞损伤和对后代的影响,染色体畸变以及染色单体互换等方面。     

加速效应在阳离子交换法分离铀同位素中的应用

本文研究了丁二酸、Ca~+的加速效应在(O_2)_~(2+)-苹果酸-Na~+排代体系分离铀同位素中的作用。对(O_2)_~(2+)-苹果酸-丁二酸-Ca~(2+) (NH_4~+)排代体系的色谱特征、铀同位素的单级分离因子ε和斜率系数δ及它们的温度系数进行研究测定并和(O_2)~(2+)-苹果酸-Na~+排代体系作了对比后,肯定了丁二酸和Ca~(2+)对(UO_2)~(2+)传质的加速效应δ使值增加63％,或ε×δ值增加37％;还明确了(O_2)_2~(2+)-苹果酸-丁二酸-Ca~(2+)(NH_4~+)体系的铀区pH是可调控的,因而具有选择最佳分离条件的优点。     

马尾藻样品中放射性核素110mAg测量及探讨

本文主要介绍了广东大亚湾核电站对海藻（马尾藻）样品中放射性核素110mAg含量的测量方法及主要结果，还给出了核电站液态流出物中110mAg排放量与专家村附近海域马尾藻样品中110mAg含量的相关分析结果。     

冠醚在Rb和Re中子活化分析中的应用研究

研究了用１８－冠－６（１８Ｃ６）和苯并１５－冠（Ｂ１５Ｃ５）的硝基苯溶液分别从给定ｐＨ范围的苦味酸水溶液或ＫＯＨ溶液中定量萃取Ｒｂ和Ｒｅ，同时研究了影响定量萃取的各种因素以及定量反萃的实验条件，用斜率确定冠醚与金属离子在溶液中生成２：１配合物，冠醚的选择性定量溶液萃取已较好地诮于中子活化分析岩石中微量Ｒｂ和Ｒｅ。     

用Calyculin A诱导的染色体凝聚研究辐射的剂量效应关系

采用不同剂量（0，0.25,0.5,1.0,2.0,3.0Gy)的60Coγ射线照射离体人血，于照后46h加入CalyculinA，观察其诱导的染色体凝聚，并与常规染色体畸变法进行比较，结果表明，Calyculin A法PCC与常规秋水仙素阻滞法及融合法PCC相比可获得更高的分裂指数，Calyculin A法PCC的断片数与剂量之间呈良好的线性关系。     

氧化镧中放射性的去除——Ⅱ.几种常用有机磷萃取剂对镧和锕的萃取分离研究

本文比较了工业上常用的几种有机磷萃取剂对镧锕的分离能力,选定2-乙基已基膦酸单(2-乙基己基)酯(P_(507))作为氧化镧除放的萃取剂,并对P_(507)萃取分离镧锕的影响因素(如平衡水相pH值,平衡水相中镧浓度及萃取剂浓度等)进行了深入研究。给出了镧锕分配比和分离系数的数学模型,为氧化镧除放射性的工艺流程设计提供了可靠的依据。