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1.
The Black Sea tritium level was investigated in 33 places southward the Danube Delta covering about 360 km of the Black Sea Western Shore. Both surface (10 cm depth) and bottom (up to 20 m depth) water samples were collected. In the close vicinity of Danube Delta, the tritium activity concentration in the surface water was around 28 TU, which is almost the same as that of the Danube River waters, but it decreased to about 5 TU in the bottom water. This discrepancy slowly diminished wherein at about 120 km southward, the tritium content in both surface and bottom water reached almost the same constant value of 6.5 ± 2.3 TU. This value, about two and a half times smaller than that reported 17 years ago, remained almost unchanged for the last 240 km of shore up to the Turkish border.  相似文献   

2.
Zusammenfassung Zur Ermittlung des natürlichen Tritiumgehaltes von Lebensmitteln wurde eine Verbrennungsanlage entwickelt, in der aus Lebensmitteln beliebiger Zusammensetzung in einem Arbeitsvorgang etwa 100 ml Wasser gewonnen werden. Zur Messung der Tritiumaktivität dieses Verbrennungswassers im Flüssigkeitsszintillationsspektrometer wird das Wasser von störenden Verbrennungsprodukten durch Destillation gereinigt. Aufbau und Arbeitsweise der Verbrennungsanlage und des Wasserreinigungssystems werden beschrieben.Die Teilnahme von S. Mlinko an diesen Untersuchungen wurden durch ein Stipendium der Alexander von Humboldt-Stiftung ermöglicht, wofür wir hier unseren herzlichen Dank sagen wollen.Frl. I. Kuschel wird für die wertvolle Mitarbeit bei den Untersuchungen gedankt.  相似文献   

3.
To investigate the natural tritium content of foods a combustion apparatus was developed, in which nearly 100 ml of water are obtained in one operation from foods of any composition. To measure the tritium activity of this combustion water in the liquid scintillation spectrometer, the interfering combustion products are removed by distillation. The construction and operation of the combustion apparatus and of the water purification system are described.  相似文献   

4.
In order to test the method of tritium determination and to determine the tritium activity, foods of known origin were investigated. The accuracy of the method over a prolonged period of time is confirmed by the statistical evaluation of the background values and of the counting efficiency. An average value of 600–800 pCi of tritium in one litre of water was found in milk, potatoes and apples. Drinking water contained very different activities of tritium, depending on its origin as ground or surface water. Food samples from the environment of nuclear reactors were not different in their tritium content when compared to those of other origin.  相似文献   

5.
本文介绍了十一种氚化甾族化合物的氚核磁共振谱。我们依照英国放化中心和英国萨里大学报道数据,(甾体骨架上的CH及CH_2各位置的谱线归属,应用了定位标记化合物作为对照)归属了其氚在化合物中标记的位置,根据其积分曲线定出了各位氚的相对百分含量。同时图谱中又提供了立体构型的信息,为氚化甾族化合物制备过程中,催化剂的选择,实验条件的控制及反应机理等研究提供了理论依据。  相似文献   

6.
Tritium in foods     
The qualities of selected scintillation systems for the measurement of very low tritium content in water samples from foods were investigated in the liquid scintillation spectrometer. The influence of the parameters of the measuring method on the detection limit was defined by figures of merit. Optimum values were obtained with an emulsion system, which consists of PPO, bis-MSB, p-xylene and Triton N-101, and which takes up 40% water. 0.16 to 0.18 pCi/ml water are detectable with this system. Reference water, which is poor in tritium, was produced by combustion of propane.  相似文献   

7.
Tritium in foods     
Zusammenfassung Es wurden die Eigenschaften ausgewählter Szintillationssysteme für die Messung sehr niedriger Tritiumgehalte in aus Lebensmitteln gewonnenen Wasserproben im Flüssigkeitsszintillationsspektrometer untersucht. Der Einfluß der Parameter der Meßmethode auf die Nachweisgrenze wurde über Wertziffern definiert. Optimale Werte wurden mit einem aus PPO, bis-MSB, p-Xylol und Triton N-101 bestehenden Emulsionssystem erhalten, das 40% Wasser aufnimmt. 0,16–0,18 pCi/ml Wasser sind mit diesem System noch nachweisbar. Tritium-armes Vergleichswasser wurde durch Verbrennung von Propan hergestellt.Die Teilnahme von S. Mlinko an diesen Untersuchungen wurde durch ein Stipendium der Alexander von Humboldt-Stiftung ermöglicht, wofür besonders gedankt wird. — Frl. I. Kuschel wird für die wertvolle Mitarbeit bei den Untersuchungen gedankt.  相似文献   

8.
Tritium concentration in ocean   总被引:1,自引:0,他引:1  
Surface seawater and water vapor about 10 m above the sea level were collected in the Pacific and Indian Oceans during the expedition of KH-96-5 to examine tritium concentrations in open sea. The tritium concentration in the water vapor was one order of magnitude higher than that in the surface seawater, attributed to downward movement of naturally occurring tritium from stratosphere to troposphere.  相似文献   

9.
锂陶瓷氚增殖剂的中子辐照性能与产氚行为   总被引:2,自引:0,他引:2  
D-T聚变堆采用氚增殖剂与中子反应生成氚来保证其燃料的“自持”。Li2O、LiAlO2、Li2ZrO3、Li2TiO3和Li4SiO4等锂陶瓷材料由于具有良好的化学稳定性、机械力学性能和产氚性能等优点,是聚变堆主要的候选产氚材料,而其在中子辐照环境下的各种性能和行为是氚增殖包层模块设计所关心的重要内容。本文介绍了国际上锂陶瓷产氚增殖剂的辐照实验研究概况,对材料的辐照性能(材料稳定性、热导性、离子电导性和活化性能等)、堆内/堆外产氚行为、影响氚在陶瓷材料中扩散或释放的各种因素,以及近来关注较多的辐照缺陷与释氚行为的相互关系等方面进行了归纳、分析和总结,同时针对中国确定的氦冷固态球床包层模块的技术路线,提出了需要广泛而系统地开展锂陶瓷基础研究的建议,指出今后国际上氚增殖剂的研究重点是高燃耗(>10%)和高荷载破坏情况下锂陶瓷材料的辐照产氚性能,以及聚变堆氚增殖包层工程条件因素,如磁场、等离子体诱发电流和中子倍增剂等对锂陶瓷小球释氚行为的影响。  相似文献   

10.
11.

Tritium concentration was monitored in different water sources collected around Kaiga Nuclear Power plant, India. The concentration was in the ranges?<?1.9–27.4 Bq L?1 (GM?=?4.0 Bq L?1) for groundwater,?<?1.9–42.1 Bq L?1 (GM?=?3.5 Bq L?1) for surface water and in 12.4–42.0 Bq L?1 (GM?=?24.07 Bq L?1) for reservoir water. The concentration values observed in this study are similar to those reported for other PHWR stations of the world. The radiation dose to the public due to ingestion of Tritium through groundwater was computed to be 0.08 μSvy?1.

  相似文献   

12.
Tritium concentration in some European foods   总被引:1,自引:0,他引:1  
High specific activity ratios of tissue-bound3H to free water3H were reported for foods in Europe und USA during 1970s and 1980s. To examine these high specific activity ratios, small number of some recent food samples imported from European countries were previously analyzed in our laboratory. The specific activity ratios obtained were around unity, and not so high as those reported by other investigators. To confirm our results, additional food samples were collected during 1988–90 and analyzed for3H. The specific activity ratios in the food samples were found to be around unity, and the previous results was confirmed.  相似文献   

13.
彭述明  王和义  傅依备 《化学进展》2011,23(7):1379-1385
氚作为一种重要的资源,在国防科技和国民经济领域有着广泛的应用。伴随着国防科技发展需求的不断提高,中国工程物理研究院在氚化学与工艺研究方面取得了一定的成就,研究领域涉及到氚的整个生命周期,包括生产、分离、储存、应用及氚废物治理等。本文重点介绍了中国工程物理研究院近年来在金属氚化物、储氚材料、氢同位素分离技术、含氚重水提氚关键技术和ITER相关氚技术等方面的研究进展。  相似文献   

14.
The tritiation of photoaffinity agents and their applications is reviewed.  相似文献   

15.
16.
本文采用紫外线激活氚原子的方法,进行氚-氢同位素交换反应,制得氚标记单磷酸阿糖腺苷(9—~3H—mparaA)。产品的纯度是层析纯;放射性比活度16GBq.m mol~(-1);放射化学纯度92.0%。本法的优点是:交换反应温和、反应时间较短、不易破坏生物活性、引起的副产物少、产品分离和纯化较方便。  相似文献   

17.
分别采用直接测量法、同位素交换法和溶解法测量铀床中的氚残留量, 并分析了这三种测量方法在本实验条件下的误差. 直接测量法测量铀床的氚残留量的结果如下: 铀床的氚残留量为2.68%, 即每克铀含(0.0308±0.0003) mmol 氚气; 当压力读数在1500~133332 Pa之间时, 基于理想气体状态方程的测量方法(简称PVT法)的标准差小于0.95%. 同位素交换法测量铀床氚的结果如下: 加热充分解吸过的铀床经多次同位素交换后, 其交换效率仅为2.84%, 即不到3%(摩尔分数)的氚被氘气载带出来, 其同位素交换法测量的标准差为7.35%. 溶解法能够彻底地测量铀床中残留的氚, 其溶解法测量的标准差为6.49%.  相似文献   

18.
There are two types of lakes in the vicinity of the nuclear fuel cycle facilities in Rokkasho-mura. One is a brackish lake, Obuchinuma Lake, and the other is a freshwater lake, Takahokonuma Lake. Tritium concentrations in Obuchinuma Lake had a good negative correlation with salinity at any sampling point and period. We consider that the water of Obuchinuma Lake has been only slightly influenced by precipitation depending on the ratio of seawater and river water of the Futamata River. Tritium concentrations in Takahokonuma Lake ranged from 0.6 to 1.5 Bq·1-1, and were higher than that in precipitation in Rokkasho-mura. Tritium concentration in rivers flowing into the lakes ranged from 0.7 to 2 Bq·l-1, and were higher than that in the precipitation. It is assumed that ground waters with higher levels of tritium inflow into the rivers.  相似文献   

19.
Tritium concentrations are reported for diet and human tissue samples collected in the Akita district of northern Japan. Sixteen separate food group samples and a total diet sample were collected for Akita City during April and May 1987. Six samples of heart and nine samples of kidney tissue were collected from 10 decreased individuals in Akita Prefecture from January to July 1986. Five serum and four blood samples were also obtained in Akita Prefecture from December 1985 to June 1986. Free water3H concentration as well as tissue-bound3H were determined separately. Specific activity ratios of tissue-bound3H to free water3H in the samples were almost between 1.0 and 2.0 and were similar to our previous results for food samples and other tissue samples. The specific activity ratio was also found to be lower than that reported in the U.S.A. and significantly lower than in Europe.  相似文献   

20.
The terpenoid compositions of the oleoresins of the oriental spruce and of the Nordmann fir growing in the Caucasus have been studied. From the oleoresin ofPicea orientalis (L.) Link, which belongs to the sectionOmorica, 32 mono-, sesqui-, and diterpene compounds have been identified, and fromAbies nordmanniana Stev. 37 mono-, sesqui, and diterpene compounds. Together with other diterpenoids that are characteristic for the oleoresins of all species of fir, methyl dehydroabietate and methyl 15-hydroxy dehydroabietate have been found in the oleoresin of the Nordmann fir. Three new sesquiterpene hydrocarbons have been isolated.  相似文献   

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