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1.
诸平  原因 《化学教育》1997,18(9):42
94号元素杯是美国核化学家,1951诺贝尔化学奖得主之一西博格(G. T. Seaborg)等人于1940年发现的。  相似文献   

2.
Pu(Ⅲ)、Pu(Ⅳ)、Pu(Ⅴ)和Pu(Ⅵ)在自然水的pH和Eh(氧化还原电势)值范围内能够共存。 在自然环境中主要以Pu(Ⅴ)的PuO2(H2O)+n和Pu(Ⅳ)的Pu(OH)4形式存在。 采用静态法测定了Pu(Ⅳ)和Pu(Ⅴ)在砂土介质中的分配系数Kd,Pu(Ⅳ)和Pu(Ⅴ)在砂土中的分配系数范围分别为5.5×103~4×104 mL/g 和3.2×103~1.1×104 mL/g。 表明在砂土介质中Pu(Ⅳ)的分配系数(Kd)大于Pu(Ⅴ)的,并且分配系数随砂土介质中粘土矿物含量的增加及介质颗粒粒径减小而增大。  相似文献   

3.
为高精度、准确地获取含钚颗粒物中具有核保障监督意义和核取证价值的钚同位素比值,建立了激光剥蚀-多接收电感耦合等离子体质谱(LA-MC-ICP-MS)测定含钚颗粒物中240 Pu/239 Pu的分析方法.采用检漏、安装排风罩和擦拭剥蚀池内壁等方式有效降低激光剥蚀产物沾污实验室和危及人身安全的潜在风险.联用扫描电迁移率粒径谱仪(SMPS)与激光剥蚀-多接收器等离子体质谱(LA-MC-ICP-MS)研究了激光剥蚀玻璃基体标样产生气溶胶的分布特性,结果表明,剥蚀产物的主要粒径是40~500 nm,应尽量采用水平管道连接激光剥蚀进样系统与MC-ICP-MS,含钚颗粒物分析后剥蚀池持续吹扫时间应大于15 min.采用外标归一化法离线校正质量分馏效应和离子计数器检测效率,建立了含钚颗粒物中240 Pu/239 Pu的LA-MC-ICP-MS分析方法,固定束斑直径30μm、脉冲重复率5 Hz、剥蚀时间5 s,调节能量密度使含钚颗粒物模拟样品中239 Pu的信号强度分别达2×104 cps和2×105 cps,本方法对240 Pu/239 Pu测量的相对实验标准不确定度小于1.4%(n=6),测量结果与参考值的相对偏差小于4.7%,仪器调试时间和单个样品测量时间分别为9.0和0.5 h.含钚颗粒物模拟样品分析结果表明,本方法精度高、结果准确、分析速度快,可满足核保障监督、禁产核查和核取证中含钚颗粒物直接分析的需求.  相似文献   

4.
It demorstrates six stable geometrical configurations of electronic states for Pu4+ using the density functional method B3LYP with relativistic effective core potentials. The most stable electronic state of Pu4+ is of the planar C2v configuration. The Jahn-Teller distortions from the configurations Pu4+(Td) and Pu4+(D4h) exist. The analysis of the relationships among these various geometrical configurations, based on the Jahn-Teller effect, vibronic interaction and the resolution of group representations, is in agreement with the calculated results.  相似文献   

5.
A rapid separation method has been developed which allows measurement of plutonium, americium and strontium isotopes in the radioactive sludge from Nuclear power plant A1 Jaslovske Bohunice (NPP A1) with high chemical recoveries and effective removal of matrix interferences. This method uses different commercial products stacked AnaLig? Pu02, AnaLig? Sr01 and TRU? Resin cartridges from IBC Advanced Technologies and Eichrom Technologies. The method allows the rapid separation of plutonium, strontium and americium using a single multi-stage column in the vacuum box (cartridge technology) with rapid flow rates to minimize sample separation time. The 239,240Pu, 238Pu and 241Am were determined by alpha spectroscopy, 90Sr was counted on TRICARB 2900 TR by Cerenkov counting of its progeny 90Y.  相似文献   

6.
The238Pu,239,240Pu and137Cs concentrations in sediments and shore deposition samples of the Vltava river were determined.239,240Pu and137Cs concentrations in sediment samples (five locations) ranged from 19.6 to 124.8 mBq·kg−1 and from 1.8 to 28.2 Bq·kg−1, respectively. The238Pu,239,240Pu and137Cs concentrations in shore deposition samples (four locations) ranged from 2 to 16.8, from 26.8 to 477.2 mBq·kg−1, and from 1.6 to 86.3 Bq·kg−1, respectively. The superficial activity of studied radionuclides in shore deposition areas was determined and radionuclide origin at studied locations was discussed.  相似文献   

7.
In this paper three different methods were used for plutonium separation and statistical tested-molecular recognition technology products AnaLig® Pu-02, liquid–liquid extraction with Aliquat-336 and extraction chromatography with TRU® Resin. The methods performance was investigated by analysis of NPL (High Alpha–Beta 2005) intercomparison sample. Regression diagnostics procedures were used for examination of the regression triplet and pair t test were applied for comparison of methods for the separation of 239,240Pu, 238Pu with Aliquat-336, TRU® Resin and AnaLig® Pu-02. The presented results were evaluated as correct for all experimental data.  相似文献   

8.
羟胺与Pu(Ⅳ)氧化还原反应动力学和机理研究   总被引:1,自引:0,他引:1  
反应机理;羟胺与Pu(Ⅳ)氧化还原反应动力学和机理研究  相似文献   

9.
The need to determine the content of plutonium in Pu–Be neutron sources of Russian provenience arises from the administrative regulations applying to nuclear materials. The determination of a plutonium (all isotopes) amount was based on the measurement of an activity Pu-239. Gamma-ray spectrometry with semiconductor detector HPGe was applied. The determination of plutonium (all isotopes) amount was based on the measurement of Pu-239 activity by means of Gamma-ray spectrometry with semiconductor detector HPGe. Gamma lines of radionuclides Am-241, Pu-238, Pu-239 and Pu-241 were detected in spectra. Detection efficiencies were calculated by Monte Carlo method using MCNP4A code. Computations were done for several hypothetical plutonium amounts. Activities determined from peak areas of 129 and 413 keV photons emitted from Pu-239 were confronted. The right amount was established under the condition of equality of both activities.  相似文献   

10.
基于PuCO分子基态()的分析势能函数,用准经典的Monte-Carlo轨线法对Pu(7Fg)+CO(0,0)的分子反应动力学过程进行了计算.结果表明,Pu(7Fg)与CO(0,0)碰撞易生成PuCO络合物分子,该反应是无阈能反应,反应截面σ随能量Et的升高而下降,当Et=502.1kJ@mol-1时,σ几乎为零.  相似文献   

11.
Curium was separated and recovered as an oxalate from a Cm–Pu mixed oxide which had been a 244Cm oxide sample prepared more than 40 years ago and the ratio of 244Cm to 240Pu was estimated to 0.2:0.8. Radiochemical analyses of the solution prepared by dissolving the Cm–Pu mixed oxide in nitric acid revealed that the oxide contained about 1 at% of 243Am impurity. To obtain high purity curium solution, plutonium and americium were removed from the solution by an anion exchange method and by chromatographic separation using tertiary pyridine resin embedded in silica beads with nitric acid/methanol mixed solution, respectively. Curium oxalate, a precursor compound of curium oxide, was prepared from the purified curium solution. 11.9 mg of Cm oxalate having some amounts of impurities, which are 243Am (5.4 at%) and 240Pu (0.3 at%) was obtained without Am removal procedure. Meanwhile, 12.0 mg of Cm oxalate (99.8 at% over actinides) was obtained with the procedure including Am removals. Both of the obtained Cm oxalate sample were supplied for the syntheses and measurements of the thermochemical properties of curium compounds.  相似文献   

12.
基于多体展式方法所导出的AlH2(X 2A1)分析势能函数,用准经典的Monte-Carlo轨迹法对Al(2Pu)+H2(X1∑+R,v=j=0)的分子反应动力学过程进行了计算.结果表明,此反应的主产物为交换反应Al(2Pu)+H2(X1∑+R,v=j=0)→AlH(X1∑+R,v′,j′)+H(2Sg)的AlH(X1∑+,v′,j′),没有发现AlH2(X2A1)络合物.而从反应的反应截面σ1与相对平动能E1的关系发现,该反应为有阈能反应,阈能值为314 kJ@mol~.同时,由于Al的质量比氢的大,发生的是直接碰撞,产物散射角分布是向前散射的.  相似文献   

13.
Two separation techniques for plutonium determination using AnaLig® Pu02 molecular recognition technology product (MRT) and extraction chromatography TRU® resin were tested. The methods performance was investigated by analysis of National Physical Laboratory (NPL-Alpha-Beta High, ABH 2003, 2005) intercomparison test samples. The results obtained for both procedures were compared in terms of activities and recoveries. Data analysis showed good agreement with the reference values. The AnaLig® Pu02 separation method for 239,240Pu, 238Pu determination was successfully validated with the same performance as the TRU® resin method.  相似文献   

14.
Two separation techniques for plutonium determination using IBCS AnaLig® Pu02 molecular recognition technology product (MRT) and extraction chromatography TRU® resin (Eichrom ®Industries) to effectively and selectively separate and recover plutonium were tested. The performance of the methods was successfully tested by analysis of NPL (High Alpha–Beta 2003, 2005) intercomparison sample and radioactive sludge sample from NPP A1 Jaslovské Bohunice with high activities of the plutonium radionuclides. The results obtained for both procedures were compared in terms of activities and recoveries.  相似文献   

15.
Hexavalent plutonium (Pu(VI)) is an important solute in the PUREX (plutonium uranium extraction) process. In 30 % TBP based PUREX solvent extraction system, distribution coefficient of Pu(VI) is much lower than that of Pu(IV). This lower distribution coefficient of Pu(VI) may cause unexpected Pu loss during primary HA extraction in low acid flowsheets. An empirical model for Pu(VI) distribution coefficients in 30 % TBP and its temperature dependency has been reported in this paper. Comparison with literature data revealed a reasonably good agreement between the reported experimental and model predicted values.  相似文献   

16.
Plutonium (Pu) metal samples from an interlaboratory exchange exercise and simulated swipe samples were dated using plutonium–uranium (Pu–U) and plutonium–americium (Pu–Am). Metal data were evaluated for consistency and the swipe data against its source material. Metal ages based on 239Pu versus 235U and 240Pu versus 236U agreed to within a few percent, while the 238Pu–234U and 241Pu–241Am measurements had larger uncertainties. Swipe ages compared favorably with the material’s known history. Neptunium (237Np) analyses were examined in the context of the 241Pu–241Am–237Np system to estimate whether Np can provide insights on material from which Am, Np, and U were removed.  相似文献   

17.
A rapid separation method has been developed which allows measurement of plutonium, americium and strontium isotopes in the high active sample from CBRN Training and Testing Centre in Zemianske Kostolany (Slovakia) with high chemical recoveries and effective removal of matrix interferences. This method uses different commercial products stacked AnaLig® Pu-02, AnaLig® Sr-01 and DGA® Resin cartridges from IBC Advanced Technologies and Eichrom Technologies. The method allows rapid separation of plutonium, strontium and americium using a single multi-stage column in the vacuum box (cartridge technology) with rapid flow rates to minimize sample separation time. The 239,240Pu, 238Pu and 241Am were determined by alpha spectroscopy, 90Sr was counted on TRICARB 2900 TR by Cerenkov counting of its progeny 90Y.  相似文献   

18.
基于多体展式方法所导出的AlH2(X^2A1)分析势能函数,用准经典的Monte-Carlo轨迹法对Al(^2Pu)+H2(X^1∑^+g,u=j=0)的分子反应动力学过程进行了计算。结果表明,此反应的主产物为交换反应Al(^2Pu)+H2(X^1∑^+g,v=j=0)→AlH(X^1∑^+,V’,j’)+H(^2Sg)的AlH(X^1∑^+,v’,j’)没有发现AlH2(X^2A1)的络合物。而  相似文献   

19.
采用本实验室建立的气溶胶直接进样ICP-MS在线定量分析技术,对取样钢瓶取得的某环境气溶胶样品进行直接进样快速分析.结果表明: 对239Pu的检出限为1.4×10-3 Bq/m3;所测样品浓度在3.1×10-3~1.2×10-2 Bq/m3之间,比法规限值低一个量级以上.  相似文献   

20.

Long chain monoamide extractants, N,N-di-decyloctanamide(DDOA), N,N-di-hexyldecanamide(DHDA), N,N-di-2-ethylhexyloctanamide(D2EHOA) and N,N-dihexyl-2-ethylhexanamide(DH2EHA) were synthesized and studied for the recovery of U(VI), Pu(IV) and Zr(IV) from a simulated dissolver solution of un-irradiated U–Zr metallic fuel. The results were compared with the results of N,N-dihexyloctanamide(DHOA) and tri-n-butylphosphate(TBP) under similar conditions. Solvent extraction studies were carried out for comparing the extraction behavior of U(VI), Pu(IV) and Zr(IV) in monoamide extractants with TBP system. The influence of length and branching of alkyl chains on either side of the amidic group on the extraction efficiency, third phase behaviour and metal ion selectivity in long chain monoamides has been discussed based on the results of above studies.

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