辛酸─1—~(13)C的合成与分析

将以溴代正庚烷为原料合成的格氏试剂溴化正庚基镁与Ｂａ１３ＣＯ３和浓Ｈ２ＳＯ４作用产生的１３ＣＯ２进行羧化反应,通过水解,提纯,制得辛酸─１─１３Ｃ,产率可达９０％─９３％。用薄层层析对其进行了定性分析,利用ＭＳ、ＩＲ、１Ｈ－ＮＭＲ和１３Ｃ－ＮＭＲ对其进行了结构分析和测定１３Ｃ丰度（８９．５％）,并按口服药物的质量要求,用ＩＣＰ－ＡＥＳ和ＡＦＳ方法对有关金属元素进行了定量测定。     

The jackknife as an approach for uncertainty assessment in gamma spectrometric measurements of uranium isotope ratios

The jackknife as an approach for uncertainty estimation in gamma spectrometric uranium isotope ratio measurements was evaluated. Five different materials ranging from depleted uranium (DU) to high enriched uranium (HEU) were measured using gamma spectrometry. High resolution inductively coupled plasma mass spectrometry (ICP-SFMS) was used as a reference method for comparing the results obtained with the gamma spectrometric method. The relative combined uncertainty in the gamma spectrometric measurements of the ²³⁸U/²³⁵U isotope ratio using the jackknife was about 10-20% (k = 2), which proved to be fit-for-purpose in order to distinguish between different uranium categories. Moreover, the enrichment of ²³⁵U in HEU could be measured with an uncertainty of 1-2%.     

Dissolution Ratio of Hydrogen Generated by Small-Leak Sodium-Water Reaction

A study, both theoretical and experimental, was undertaken on the hydrogen dissolution ratio in liquid sodium, with the view of estimating the quantity of hydrogen that dissolves into sodium before reaching the free surface, following the occurrence of sodium-water reaction in a steam generator. Superheated steam was injected into the sodium in a reaction vessel of configuration simulating the steam generator. The hydrogen dissolution ratio was determined from analysis of the responses obtained on a hydrogen detector installed downstream of the reaction vessel.

The hydrogen dissolution ratio was found to vary from o to 15% over a leak rate ranging of 3~10 g/sec, as determined both from the transient response data given by the hydrogen detector and from the corresponding data obtained from tests on changes in hydrogen concentration upon complete mixture with the entire sodium inventory.

A theoretical model was assumed for estimating the hydrogen dissolution ratio, which yield results in good agreement with the experimental data, in respect of the rising tendency of the dissolution ratio with decreasing leak rate and with rising sodium temperature.