Study on Coordination of Amidoxime Small Molecule Ligand with Uranyl Ion under Seawater Condition

正It has been found that uranium concentration in seawater is consistent in various locations around the world,even at depths up to 5 000 feet,at 3 parts per billion(ppb).With constant     

基于DNA酶的铀酰离子传感方法

铀在核能发展中扮演着十分重要的角色,铀污染的防治是一个必须解决的问题,因此对铀酰离子(UO_2~(2+))的检测方法研究,成为了人们关注的热点。DNA酶具有高度的特异性识别能力,是一种理想的生物探针。本文简要介绍了DNA酶的结构特征,概述了近期发展的基于DNA酶的UO_2~(2+)传感方法,包括比色法、荧光法、表面增强拉曼光谱法、共振光散射法和电化学法等,主要介绍了杂交链反应和目标催化发卡组装两种无酶放大技术。DNA酶的使用使得传感器对UO_2~(2+)的检测能力基本上在纳摩尔量级,展现出很高的灵敏度,结合生物无酶放大技术后,传感器的性能得到数量级的提高。在未来传感技术简单、快速、灵敏和便携的趋势下,基于DNA酶的传感器具有非常广阔的应用前景。     

Precipitation Reaction of Uranyl Ion in Molten Potassium Thiocyanate

The qualitative and the quantitative analyses of the reaction products obtained by heating uranyl solution of molten potassium thiocyanate were carried out. It was found that in the presence of water in the melt, uranyl ion is converted into UO₂ accompanied with the evolution of CO₂ and the formation of free sulfur. The molar ratios on these products were almost equal to each other.

By detecting ammonia in reaction products, it was concluded that the precipitation reaction of uranyl ion in the melt is expressed as follows:

UO₂ ⁺⁺ + SCN^? + 2H₂O = UO₂ + CO₂ +S+ NH₄ ⁺.     

有机荧光探针在铀酰离子检测方面的研究进展

荧光分析法是检测铀酰离子最主要的方法之一,它具有设备简单、高灵敏度和高选择性等优点。本文主要阐述了近几年来有机荧光分子在铀酰离子检测领域的研究进展,主要包括有机荧光染料、含氧酸等天然荧光/药物分子,以及利用席夫碱、卟啉、偕氨肟等官能团构筑的有机荧光分子和AIE型荧光分子等。这为后续性能优异的有机荧光探针的分子设计和铀酰离子检测等研究工作提供了借鉴。     

MIPR燃料硝酸铀酰溶液中痕量氟、氯离子的测定

采用水蒸气蒸馏法分离出硝酸铀酰溶液中的痕量F-、Cl-,并用离子色谱对F-、Cl-进行测定,对F-、Cl-分离条件和测定条件进行了讨论。该法的线性范围为0.04~0.3 mg/L,线性相关系数大于0.999,相对标准偏差小于10%,样品的加标回收率为94%~97%。     

Complexation of Uranyl Nitrate and Lanthanide Nitrate with TBP in Supercritical CO_2 and Molecular Dynamic Simulation

正Treatment of nuclear waste with supercritical CO_2 extraction technology has promising potential to be industrialized,and important progresses have been made in regarding actinides and lanthanides extraction.Even though,separation of actinides and lanthanides is difficult and not well studied.Here,the complexation of uranyl     

Scale-Up Preparation of Uranium Amalgam from Uranyl Ion Using Two-Compartment Electrolyzer

A solid uranium amalgam containing as high as 1.7 g U/ml Hg was prepared electrolytically using a two-compartment electrolyzer separated with a cation exchange membrane at a kilogram scale. The design and operation characteristics of the electrolyzer is described. The results indicate that ca. 170 g of uranium ion in an aqueous solution could be reduced to metallic state by forming amalgam within 4h with a current efficiency of 30% and uranium recovery of more than 80%     

铀酰离子印迹聚合物的合成及在分析中的应用

以UO₂²⁺为印迹离子,偶氮二异丁腈（AIBN）为引发剂,邻苯二酚-UO₂²⁺-4-乙烯基吡啶三元配合物为模板,与苯乙烯单体、交联剂二乙烯基苯在甲醇溶液中通过共聚反应制备了UO₂²⁺印迹聚合物微球。该印迹聚合物微球经6mol/LHCl处理后留下与铀酰离子大小相匹配的空穴,对水溶液中微量铀有富集作用,在pH＝5～7及吸附时间在20min以上时,该印迹聚合物微球对水溶液中微量铀的吸附率可达99%以上,且具有良好的选择性;HCl浓度在1.0mol/L以上,淋洗体积为聚合物体积的5倍以上,淋洗时间在20min以上时洗脱率可达99%以上。将其应用于卤水中微量铀的测定,与标准方法相比较,所得结果令人满意。     

Reduced Partition Function Ratio of Uranyl Ion and Uranium Isotope Effect

Density of 30v/o tri-n-butyl phosphate-n-dodecane solution loaded with uranyl nitrate, nitric acid and water was measured. An empirical density equation was derived from regression analysis of the density data. The equation represents the density values well in a wide range of composition and temperature.     

偕胺肟聚丙烯腈对铀酰离子吸附热力学及动力学过程分析

放射性含铀废水会带来环境污染风险,合理有效处理含铀废水十分必要。本研究通过吸附实验探究偕胺肟聚丙烯腈（AO-PAN）对U（Ⅵ）的吸附特性,系统研究吸附温度、初始浓度、吸附时间对AO-PAN吸附U（Ⅵ）的影响。结果表明,随着吸附温度升高,AO-PAN对U（Ⅵ）的吸附量逐渐增加,在343 K温度时吸附量达201.6 mg/g。不同温度条件下随着吸附时间增加,AO-PAN对U（Ⅵ）的吸附量逐渐升高,吸附初始时吸附速率较快,随着吸附逐渐进行吸附曲线逐渐趋于平缓,最终达到吸附平衡。AO-PAN对铀的吸附量随溶液中初始浓度的增加而升高,温度为303 K,溶液中初始铀浓度为500 mg/L时,AO-PAN对U（Ⅵ）的吸附量达305.8 mg/g。此外,AO-PAN对铀酰离子的吸附符合朗格缪尔（Langmuir）模型,吸附热力学分析表明AO-PAN对铀酰离子的吸附是吸热和自发过程,吸附动力学分析表明AO-PAN对铀酰离子的吸附行为遵循准二级动力学模型,吸附速率控制机理分析表明AO-PAN对U(Ⅵ)的吸附初始受颗粒内扩散过程控制,随着吸附不断进行吸附过程逐渐由颗粒内扩散控制变为液膜扩散过程控制。吸附实验结果表明,AO-PAN是一种优良的吸附剂,可以用于吸附废水中U(Ⅵ),吸附过程的模型方程可以用于AO-PAN对U(Ⅵ)吸附过程的分析和计算。     

Electrochemical Properties of Uranyl Ion in Ionic Liquids as Media for Pyrochemical Reprocessing

We have proposed a new reprocessing process by using ionic liquids (ILs) instead of molten salts of alkali chlorides in pyrochemical process. In the proposed process, spent nuclear fuels are dissolved in ILs by using Cl₂ as an oxidant, and UO₂ ²⁺ and PuO₂ ²⁺ ions in ILs are recovered as UO₂ and PuO₂ by electrochemical reduction. In order to examine applicability of ILs as media for reprocessing, we have studied electrochemical behavior of UO₂ ²⁺ in 1-butyl-3-methylimidazolium chloride (BMICl), 1-butyl-3-methylimidazolium tetrafluoroborate (BMIBF₄), and 1-butyl-3-methylimidazolium nonafluorobutanesulfonate (BMINfO). Electrochemical properties of uranyl chloride dissolved into ILs were examined by cyclic voltammetry. In BMICl, an almost reversible redox couple was observed, and the formal potential and the diffusion coefficient were evaluated as _0:758V vs. Ag/AgCl and 4:8 × 10^?8 cm²s^?1, respectively. On the other hand, the electrochemical reactions of UO₂ ²⁺ in BMIBF₄ and BMINfO were irreversible. In BMINfO, some reduction peaks and one sharp oxidation peak were observed in the range of ?0:6～–0:2V and around 0.85V vs. Ag/AgCl, respectively. The reduction and oxidation peaks were assigned to multi step reduction of UO₂ ²⁺ to U(IV) via U(V) and/or direct reduction of UO₂ ²⁺ to U(IV), and the oxidative dissolution of the resulting U(IV) compounds, respectively. The electrochemical reduction of UO₂ ²⁺ in BMINfO at ?1:0V vs. Ag/AgCl produced the deposits on a carbon electrode as a cathode. Analyses of the deposits with the scanning electron microscope and the energy dispersive X-ray spectrometer indicated that the deposits are compounds containing uranium, oxygen, and chlorine. As a result, it is expected that the UO₂ ²⁺ in IL can be recovered electrolytically as uranium compounds such as UO₂ and uranium oxychlorides.     

Study on Temperature Effect of Uranyl Nitrate Solution Experiment Facility

本工作用HI-13串列加速器产生的准直重粒子束$32对不同厚度的聚酯薄膜进行了不同密度的照射。在后期的化学蚀刻处理过程中，对各蚀刻条件（蚀刻液浓度、温度和蚀刻时间）进行最优化选择。研究了不同条件下聚酯薄膜中生成的不同大小和形状的径迹孔洞，以及具有这些孔洞的样品在近红外区的透过率。     

含氟生物浸出体系中阳离子竞争络合解毒机理研究

针对生物浸出体系中氟对浸矿微生物的抑制问题,提出结合氟的溶液化学性质,利用金属阳离子的竞争络合作用,使溶液中的游离F^-形成络合态,进而使细菌可耐受高氟浓度生长。比较了不同金属氟化物对细菌生长的影响,结果显示：AlF₃和FeF₃性质稳定,对细菌生长无明显影响;MgF₂溶于浸出体系释放F^-,对细菌产生毒害作用。热力学分析结果表明,Al³⁺、Fe³⁺对F^-的竞争络合机理以及Mg²⁺对F^-无竞争络合符合热力学定律。比较了Al³⁺和Fe³⁺对F^-的解毒能力,结果表明,Al³⁺、Fe³⁺对氟均有解毒作用,解毒能力大小为Al³⁺>Fe³⁺。通过PHREEQC计算可知,络合物形态可通过调节溶液中F^-与金属离子的浓度控制,且随着F^-与金属离子浓度比的减小,配位数向低配位方向移动。     

Spectroscopic Flow and Ion Temperature Studies of a Large s FRC

The Swarthmore Spheromak Experiment (SSX) produces a large s FRC by merging counter-helicity spheromaks within a cylindrical flux conserver. Past results have shown that the toroidal fields in each spheromak do not annihilate even after the poloidal flux appears to have completely reconnected. This would suggest a radially directed current density at the midplane, and therefore a radially sheared azimuthal component of J × B. In contrast, fast high resolution spectroscopic measurements indicate that flow at the midplane is small (u < < v _A ) and there is little shear.     

超铀元素络合行为研究进展

超铀元素与地下水中可能存在的无机及有机配位体的络合会影响它们在水中的浓度及其迁移行为。文献研究表明，对Np、Pu来说，四价离子的络合能力最强，五价离子的络合能力最弱。在地下水中可能存在的无机阴离子中，CO3^2-的络合能力最强，Pu4 与CO3^2-络合的稳定常数尚未准确确定。当Pu(Ⅳ)以PuO2存在时。CO3^2-的存在能影响其溶解度，但影响不大。虽然五价Np的络合能力比其它价态的弱，但它与CO3^2-、HPO4^2-、PO4^3-等的络合物还是很稳定的。CO3^2-的存在能提高Np(Ⅳ)溶解度，但影响不大。醋酸根、乳酸根、草酸根、柠檬酸根、α-羟基异丁酸根、EDTA、抗坏血酸根、α-羟基喹啉、噻吩甲酰三氟丙酮等有机配位体能与NpO2^ 形成相当稳定的络合物。但当存在其它常量的金属(如Fe、Mg、Ni、Pb)离子时，这些有机物对Np(V)溶解度的影响不一定明显。腐殖酸与Np(Ⅴ)的络合物相当稳定，腐殖酸与Am(Ⅱ)的络合物更加稳定。     

氢化钛镍合金阴极真空弧放电离子特性研究

本文将氢化钛镍合金材料应用于强流长脉冲（200 A/270 μs）真空弧放电实验中,该材料能在强流长脉冲真空弧放电产生的高温条件下保持较好的稳定性。使用飞行时间谱仪获得了氢化钛镍合金阴极真空弧放电产生的离子电荷态分布和离子成分。结果表明：Tiⁿ⁺和Niⁿ⁺电荷态为1+、2+和3+,在放电过程的早期（0~30 μs）,H⁺成分随时间逐渐增加,在30 μs时达到最大比例57%,而Tiⁿ⁺和Niⁿ⁺（n=1,2,3）离子成分随时间逐渐减少,在30 μs时达到最小比例43%;在放电过程的后期（30~270 μs）,H⁺成分迅速下降且在75 μs后保持在总离子流的12%左右直至放电结束,Tiⁿ⁺和Niⁿ⁺（n=1,2,3）含量随时间逐步增加,且在75 μs后保持在总离子流的88%左右直至放电结束。     

Experimental Study on Fluoride Volatility Process for Thorium Fuels

Selective removal of uranium from (Th/U)O₂ by fluorination with fluorine was studied experimentally. The fluorination was performed both in a small boat and in a 2 inch inner diameter fluid-bed reactor.

Fuel particles tend to agglomerate in the reactor due to the large amount of reaction heat and the comparatively low melting point of ThF⁴. The fluorinated fuels produced in the fluid-bed reactor were found to be partially agglomerated. Fractional retention of uranium was smaller in the agglomerated parts than in the un-agglomerated, and smaller in the outer layers of the cakes than in the core.

On the other hand, it was also established beyond doubt from the results of the small boat fluorination experiment that heavy agglomeration inhibits the volatilization of uranium in the form of UF₆. Inhibition of the violet exothermic reaction by lowering the fluorine pressure in the early stage of fluorination was found to be a very effective method of obtaining high uranium recovery. It was demonstrated that more than 99% of the uranium could be volatilized within 4 to 5 hr at a temperature of 580°C.

The experimental results on the effects of temperature, particle size and fluorine concentration are presented. The variations of reaction rate observed in the course of fluorination are also discussed.     

模拟放射性含氟废液水泥固化配方的研究

本文以沸石、硅灰、石英砂为添加剂,按照质量比m（沸石）∶m(硅灰)∶m（石英砂）∶m（水泥）=1∶1∶3∶10配方对模拟放射性含氟废液进行水泥固化。由配方得到的水泥浆流动度和初、终凝时间满足桶内固化要求。测定了水泥固化体28 d的抗压强度、抗浸泡性和抗冻融性实验后的强度损失,进行了抗冲击性能测试和模拟核素浸出实验。结果表明,该配方可有效地固化模拟放射性含氟废液,固化体28 d抗压强度、各项实验强度损失和模拟核素浸出率均满足GB 14569.1-2011的要求。水泥固化体的F^-浸出率很低,XRD显示F^-以CaF₂形式存在。废液中F^-质量分数控制在1%较为合适,此时水泥固化体终凝时间为14 h,F^-的42 d浸出率为2.54×10^-3 cm/d。