铀化合物中微量钽的萃取色层分离—ICP／AES测定

以CL-TBP萃取色层分离-水平式ICP/AES测定铀化合物中微量Ta。方法是先将铀化合物转化成硝酸铀酰,再以含0.2mol·l ?HF的3mol·l~(-1)HNO_3溶液溶解微量Ta,然后进行分离和测定。取样0.3g,测定下限为0.5×10~(-6);当Ta含量为1.7×10~(-6)-5.0×10~(-6)时,方法的加入回收率在88%106%范围内;相对标准偏差≤10%。     

季铵萃淋树脂色谱分离—ICP／AES法测定核纯级UO2中7种杂质元素

应用237-季铵萃淋树脂色谱分离技术,将核纯级UO_2中铀与待测杂质元素在6.5 mol·l~(-1)HNO_3。介质中定量分离后,以975型ICP直读光谱仪同时测定Ba、Be、Nb、Ru、Sb、Sn和Ta。取样200mg时,测定下限为0.013×10~(-6)-0.50×10~(-6);当各元素含量约为1.0×10~(-6)时,方法的加入回收率在98%-103%范围内;相对标准偏差<5%。     

UF_6中稀土元素的中子活化分析

本文叙述了UF_6中14个稀土元素(REE)的中子活化分析。将UF_6水解液转化为HNO_3介质,采用TBP色层,PMBP萃取,高压阳离子交换色谱以及D_2EHPA色层进行化学分离。方法的灵敏度在3×10~(-10)-2×10~(-12) g之间,回收率在90%以上。相对标准偏差在±20%以内。     

电感耦合等离子体原子发射光谱法测定铀氧化物中微量碱金属元素

采用电感耦合等离子体原子发射光谱法(ICP-AES)测定铀氧化物中Li、Na、K、Cs等碱金属元素的含量。用CL-TBP萃淋树脂为固定相、3 mol/L硝酸溶液为流动相,定量地分离基体铀与杂质元素,溶液中的杂质含量用光谱仪测定。对仪器工作参数的优化条件进行了介绍,确定了元素的分析波长,进行了标准曲线与工作曲线无显著性差异的一致性评价,采用峰高积分法降低了Cs元素的电离干扰。用方法比对和加标回收两种方式验证了实验方法的准确性与有效性。结果表明:Li、Na、K、Cs的相对标准偏差优于15%(n=6),分析方法回收率为90%～110%,在Li质量分数为21.2μg/g时,测量结果的相对扩展不确定度U_rel(Li)=7.2%(K=2)。     

ICP—AES法测定陶瓷UO_2芯块粉末标准物质中Al、Ba、Co、Ta、Ti和V

本法采用237—季铵萃取树脂,利用萃取色谱分离技术,将陶瓷UO_2芯块粉末中铀与待测杂质元素在6.5mol/L HNO_3介质中定量分离后,用975型ICP直读光谱仪同时测定流出液中Al、Ba、Co、Ta、Ti和V,取样300mg时,测定下限为0.016×10~(-6)-0.25×10~(-6),RSD<7.5％。分析结果均落在标准值的置信区间内。     

萃取色层分离-水平式ICP/AES法测定U_3O_8中25种杂质元素

文章叙述了用TBP萃取色层法分离,水平式ICP/AES法测定U_3O_8中25种杂质元素的分析方法。样品转化为硝酸铀酰后,采用以CL-TBP萃淋树脂为固定相,5mol/l HNO_3为流动相的萃取色层法使杂质元素与铀基体分离,杂质流出液以水平式ICP为激发光源的发射光谱分析法直接测定,取样0.3g,所有元素的测定下限在0.01×10~(-6)～5×10~(-6)之间,方法的重加回收率在82%～121%之间,相对标准偏差在13%以内。     

萃取色层分离-水平式ICP/AES法测定U_3O_8中Hf,Zr,Sc,Th,Ag

本章叙述了用萃取色层分离-水平式ICP/AES法测定U_3O_8中Hf,Zr,Sc,Th,Ag等杂质元素。U_3O_8样品用HNO_3-HF混合酸溶解,并用HCl转化成氯化铀酰后,通过以CL-TBP萃淋树脂为固定相,5mol/l HCl为流动相的萃取色层柱,将杂质元素与铀分离后,以水平式ICP为激发光源,在W-100型平面光栅摄谱仪上进行光谱测定。取样0.3g时,测定下限Hf,Zr,Th为0.23×10~(-6),Sc为0.023×10~(-6),Ag为0.04×10~(-6),重加回收率在84%～114%范围内,相对标准偏差低于10%。     

二苯并-18-冠-6对某些放射性核素的萃取与萃取色层分离

本文研究了二苯并-18-冠-6对~(22)Na、~(45)Ca、~(86)Rb、~(90)Sr-~(90)Y、~(137)Cs和~(144)Ce等放射性核素的萃取和萃取色层分离。冠醚萃取金属离子具有离子对萃取的特征,据此,选择苦味酸根离子为反离子,以三氯甲烷为溶剂。 测定了30℃时Na~+、Rb~+、Cs~+、Ca~(2+)、Sr~(2+)和Ce~(3+)的萃取平衡常数(K_(ex))。对单价和二价金属离子,K_(ex)次序分另0为;Rb~+>Cs~+>Ns~+和Sr~(2+)>Ca~(2+)。 使用二苯并-18-冠-6的萃取色层有效地分离了~(22)Na-~(137)Cs、~(45)Ca-~(90)Sr和~(144)Ce-~(90)Sr-~(90)Y。     

阳离子交换分离ICP-AES法测定高放废液中微量钌、铑、钯

用盐酸及氯化钠处理后的高放废液试样,通过强酸型阳离子交换树脂柱,杂质元素被吸附在树脂上,Ru、Rh和Pd以氯络阴离子形式存在,流入淋洗液中。分离纯化后的试液用ICP-AES法测定其中Ru、Rh和Pd的含量。Ru含量在(35—230)×10~(-6)范围内,重加回收率为90%,相对标准偏差(RSD)为6%;Rh含量在(2—20)×10~(-6)时,重加回收为106%,RSD为10%;Pd含量小于2×10~(-6)时重加回收为72%。     

~(60)Co和~(137)Csγ辐射场的照射量率的比对

用NPL防护水平次级标准NE2550剂量率仪对国防计量系统和有关厂矿的防护水平~(60)Co和~(187)Cs γ辐射场进行了照射量率的测量和反平方律的检验,并作了照射量率的比对。~(137)Cs γ辐射场照射量率最大相差+3.6％(2.58×10~(-6)-2.58×10~(-4)Ckg~(-1)h~(-1)),而~(60)Co γ辐射场最大相差分别为+1.4％(2.58×10~(-4)-2.58×10~(-3)Ckg~(-1)h~(-1))、+9.9％(2.58×10~(-6)-2.58×10~(-4)Ckg~(-1)h~(-1))和+24.5％(2.58×10~(-7)-2.58×10~(-6)Ckg~(-1)h~(-1))。~(60)Co和~(137)Cs γ辐射场的照射量率,在一定的距离范围内反平方律在±5％以内符合。     

辐射交联聚乙烯泡沫塑料的阻燃研究

以氯化聚乙烯（ＣＰＥ），十溴联苯醚（ＤＢＤＰＯ）及三氧化二锑（Ｓｂ２Ｏ３）作为聚乙烯泡沫塑料的阻燃剂，研究了氯化聚然在辐照条件下对聚乙烯泡沫塑料的影响及其阻燃性，实验表明，氯化聚乙烯的存在强化了聚乙烯的辐射交联，而氯化聚乙烯，十溴联苯醚及三氧化二锑的联用聚乙烯泡氧指数超过３０，甚至自熄，同时三元体系的阻燃剂的使用不影响乙烯泡沫塑料的成型，发泡等工艺。     

火焰原子发射法测定硝酸铀酰中的微量铯

对铀化物中的杂质元素,化学工作者通常是先将铀基体分离掉,然后再用分光光度、原子吸收等方法进行测定。但,迄今我们没有见到用原子吸收分光光度计以FAES为分析手段的测定铀化合物中铯元素的报道。铯的火焰原子吸收法测定,灵敏度较低。欲用加大样品量的方式去适应测定需要,势必给萃取分离带来困难。而具有较高灵敏度的FAES法可以满足测定要求。因铯的电离电位很低(3.95 eV),测定时存在严重的电离效应的不利影响,我们试图加入钾的硝酸盐予以消除;这一尝试终于取得了令人满意的效果。不过,出于对样品测定时信噪比的考虑,鉴于背景发射随钾盐量增加而增大,因而严格控制其钾的加入量是至关重要的。     

FAAS法测定α—Zr固溶体溶出物中Sn,Fe,Cr的含量

叙述了火焰原子吸收分光光度法（ＦＡＡＳ法）直接测定非水解电液中Ｓｎ，Ｆｅ和Ｃｒ离子浓度的方法，该法采用标准曲线法，直接吸样品溶液，并用与电解液介质成分相匹配的乙醇，正丁醇，高氯酸混合基体溶液配制标准液，Ｓｎ，Ｆｅ直接测定，Ｃｒ用标准加入法校准。当采用多点校准曲线时，Ｆｅ，Ｃｒ和Ｓｎ的相关系数分别为０．９９９３，０．９９９８和１．００００。同时，进行了４种合金成分间相互干扰及主要共存元素对被测元素的     

骤冷网格对层流火焰影响的数值分析

利用计算流体力学(CFD)方法,研究二维简化情形下骤冷网格对层流火焰传播的影响。数值分析结果表明:随着火焰的传播,层流火焰前沿在接近骤冷网格的过程中,向金属网格的传热逐渐超过氢气燃烧产生的化学热,最终火焰的传播被骤冷网格终止。     

Analysis of hydrogen flame acceleration in APR1400 containment by coupling hydrogen distribution and combustion analysis codes

This study was conducted as part of the construction of an integrated system to mechanistically evaluate flame acceleration characteristics in a containment of a nuclear power plant during a severe accident. In the integrated analysis system, multi-dimensional hydrogen distribution and combustion analysis codes are used to consider three-dimensional effects of the hydrogen behaviors. GASFLOW is used for the analysis of a hydrogen distribution in the containment. For the analysis of a hydrogen combustion in the containment, an open-source CFD (computational fluid dynamics) code OpenFOAM is chosen. Data of the hydrogen and steam distributions obtained from a GASFLOW analysis are transferred to the OpenFOAM combustion solver by a conversion and interpolation process between the solvers. The combustion solver imports the transferred data and initializes the containment atmosphere as an initial condition of a hydrogen combustion analysis. The turbulent combustion model used in this study was validated by evaluating the F22 test of the FLAME experiment. The coupled analysis method was applied for the analysis of a hydrogen combustion during a station blackout accident in an APR1400. In addition, the characteristics of the flame acceleration depending on a hydrogen release location are comparatively evaluated.     

Loading pattern optimization for a PWR using Multi-Swarm Moth Flame Optimization Method with Predator

ABSTRACT

This paper aims to propose a new methodology for optimizing fuel loading pattern in a nuclear reactor which is important for its higher safety and economic efficiency. Previous researches have proposed various methodologies to decide better loading patterns automatically. However, the processes still require manual operations of engineers to automatically design actual loading patterns. Swarm intelligence algorithm has currently gained interest as a solution to seek the patterns. Although these methodologies generate better patterns, they sometimes struggle with getting out from local optima and fails to complete the optimization. Large and multimodal solution space sometimes captures worse solutions due to local optima. The conventional methodologies struggle with setting proper parameters to get out from local optima. This research focuses on Multi-Swarm Moth Flame Optimization with Predator (MSMFO-P), an improved Moth Flame Optimization (MFO) by applying the concepts of predator and multi-swarm, as new methodologies. The method of MSMFO-P was applied to solve a loading pattern problem and compared with the conventional optimization methods such as simulated annealing (SA), Hybrid genetic algorithm (GA), and particle swarm optimization (PSO). The results of our experimental works indicated that MSMO-P generates better loading patterns than the conventional methodologies.     

辐射制备POE/EPDM/SR/MH无卤阻燃绝缘材料的研究

使用电子加速器辐照制备了由聚烯烃弹性体(POE)、三元乙丙橡胶(EPDM)、硅橡胶(Siliconrubber)和氢氧化镁混炼而成的无卤阻燃绝缘材料,研究了配方对共混体系力学性能、阻燃性能、电性能等的影响。探索了力学性能与吸收剂量之间的相关性,研究了含硅体系与含硅磷体系各自的阻燃机理。发现拉伸强度与凝胶含量无直接对应关系,屈服强度与凝胶含量在一定剂量范围内有良好的对应关系;硅橡胶的加入可促进体系成炭,硅橡胶与红磷有协同阻燃作用。     

Stopping powers of Be,Al, Ti,V, Fe,Co, Ni,Cu, Zn,Mo, Rh,Ag, Sn,Ta, Pt and Au For 6.5 MeV protons

The stopping powers of Be, Al, Ti, V, Fe, Co, Ni, Cu, Zn, Mo, Rh, Ag, Sn, Ta, Pt and Au for 6.5 MeV have been measured using a surface barrier silicon detector. The accuracy of the results is ± 0.3%. The detail of the experimental procedures is described. The results have been compared with the Risø data and the Aarhus data of Andersen et al. The present results for Al, Cu and Ag agree very well with the Aarhus results at 6.5 MeV. The mean excitation energy has been extracted from the present results using the Bonderup shell correction, the Barkas correction and the Bloch correction. The parameters x and b which appear in the Bonderup shell correction and the Barkas correction have been newly determined as x = 1.358 and b = 1.3. The present mean excitation energy agrees very well with the I values obtained by other authors. It has been confirmed that the Bonderup shell correction is quantitatively correct for 6.5 MeV protons.     

Wavelengths,transition probabilities,and oscillator strengths for M-shell transitions in Co-, Ni-, Cu-, Zn-, Ga-, Ge-, and Se-like Au ions

Wavelengths, transition probabilities, and oscillator strengths have been calculated for M-shell electric dipole transitions in Co-, Ni-, Cu-, Zn-, Ga-, Ge-, and Se-like Au ions. The fully relativistic multiconfiguration Dirac–Fock method, taking quantum electrodynamical effects and the Breit correction into account, was used in the calculations. Calculated energy levels of M-shell excited states for Cu-, Zn-, Ga-, Ge-, and Se-like Au ions from the method were compared with available theoretical and experimental results, and good agreement with them was achieved.