基于奇异值分解方法的嫦娥一号γ射线谱仪谱线定性分析

针对嫦娥一号γ射线谱仪(CE1-GRS)探测数据难以从谱形特征直接进行定性分析的问题,提出采用噪声调整的奇异值分解(NASVD)方法提取CE1-GRS数据中相互正交的谱线主成分,然后分别分析月表各区域对应谱线的低序层谱线中的峰信号,通过鉴别各峰信号对应的能量值是否等于特定元素的特征γ射线能量来确定月表各区域的元素种类。结果表明,该方法能够识别出的月表可能元素包括U、Th、K、Fe、Ti、Si、O、Al、Mg、Ca和Na等11种元素。     

用仪器中子活化分析测岩石中痕量稀土元素的含量

岩石中主要元素为Si、Fe、K、Na、Ca等,有的还有U和Th等成分。照射后,对各稀土元素同位素的干扰相当复杂。在岩石的INAA中,为了尽量避免和减少干扰,利用中科院地化所提供的RT-1012、RT-1018玄武岩试样在照射后专门做了条件实验(每间隔一天进行一次测定分析),选出了各核素的最佳测定能峰、冷却时间和测定时间,对无法避免的有关干扰     

色层分离—原子吸收／火焰光度法测定UO2中痕量碱金属元素

色层分离-原子吸收/火焰光度法是为分析测定动力堆元件、UO_2粉末和芯块中痕量Li、Na、K和Cs而研究建立的标准分析方法。样品用HNO_3溶解后调成5.5 mol·l~(-1)HNO_3介质,通过TBP色层柱,将待测元素与U分离。分别用FAAS和TAES法测定淋洗液中的Li、Na、K和Cs。取样量为0.5g时,4个元素测定下限均为2×10~(-6)。K和Na含量为10×10~(-6)、Li和Cs为5×10~(-6)时,加入回收率为96%-106%。相对标准偏差在7%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21.2 μg/g时,测量结果的相对扩展不确定度U_rel(Li)=7.2%(K=2)。     

NASVD方法在CE1-GRS谱线分析中的应用研究

直接从谱形特征上对嫦娥一号伽玛射线谱仪(CE1-GRS)的3级谱线数据进行分析,难以确定月表元素的种类。提出采用噪声调整的奇异值分解(NASVD)方法对CE1-GRS谱线进行定性分析。分析结果表明,该方法能够识别出的月表可能元素包括U、Th、K、Fe、Ti、Si、O、Al、Mg和Ca等10种元素,也能够通过各观测谱线对应于第一主成分的幅度绝对值大小反映对应月表区域的总放射性活度强弱。     

TBP色层分离-超声波雾化-ICP/AES法测定二氧化铀中二十一个微量杂质元素

选用TBP(磷酸三丁酯)柱上分离技术分离铀与待测元素,超声波雾化进样,ICP-AES法对二氧化铀中二十一个微量杂质元素测定的工作参数、酸度干扰、共存元素干扰、载气流量的选择、去溶温度等进行了试验研究。当取样量为250mg时,Al,Ag,Ba,Ca,Cd,Co,Cr,Cu,Fe,In,Li,Mg,Mn,Mo,Ni,Pb,Sn,Ti,V,Y和Zn的测定范围是0.2～100ng·g~(-1),回收率为94％～110％,RSD(n=8)为0.8％～6.2％。     

电感耦合等离子体原子发射光谱分析法(ICP-AES)测定金属钙中硅、铁、锰、铬、镁、铝、铜、镍、钠杂质元素的含量

本文叙述了一种适合于较浓溶液的进样——去溶装置,考察了ICP光源主要工作参数对谱线△s的影响,观察了ICP光源中的基体效应和共存元素的干扰,为金属钙中杂质元素的测定选择折衷工作条件。方法无需分离,简便、快速。方法的检测范围为:Mg——50—5000 ppm;Al——30—3000 ppm;Na——16—1600 ppm;Si、Fe、Cr、Ni——10—1000 ppm;Cu、Mn——3—300 pPm,方法的标准偏差为4—10%,回收率为92—104%。     

用感应耦合等离子体发射光谱法测定岩石中的铀

本文介绍了用发射光谱法进行岩样中铀的定量测定。岩石样品经溶解后制成溶液,然后将其喷入感应耦合等离子体激发光源。对若干条不同类型的谱线进行了研究,并选用了铀378.28nm发射谱线作分析线,因为这条谱线相对来说不受基体元素谱线的干扰。应用这条谱线选择最佳的光源参数(功率,气体流速,观测高度)测定的实际检出限为0.1ppm。所得分析结果与其它一些分析方法的分析结果作了比较。     

粉末压片—WDXRF测定化探样品中主次痕量元素

采用粉末压片法制取试样、X射线荧光光谱法测定化探样品中33种主、次、痕量元素(Al、As、Ba、Br、Ca、Ce、Co、Cr、Cu、Fe、Ga、Hf、K、Mg、Mn、Na、Nb、Nd、Ni、P、Pb、Rb、Sc、Si、Sr、Th、Ti、U、V、Y、Yb、Zn、Zr)。对各元素的测定条件、仪器参数进行了设置调整,选取了与试样基体相匹配的定值样品建立工作曲线,对曲线拟合进行了研究,用经验系数法和Compton散射线内标法相结合校正基体效应,提高了分析精度。经对标准物质的验证,分析结果与标定值吻合,方法的检出限和精度均满足分析要求,相对标准偏差(RSD,n=11)为0.1~10%,满足多目标地球化学调查样品分析的质量要求,可用于化探样品的常规分析。     

萃取色层分离/ICP-AES法测定钆铀氧化物中的杂质

研究了钆铀氧化物中29种杂质元素的测定。采用CL-TBP从硝酸溶液中萃取色层分离基体铀，所得含杂质及钆的淋出液以电感耦合等离子体原子发射光谱仪采用多组分图谱拟合法(MSF)测定。研究了MSF模型的建立与考查、不同杂质浓度下的回收率等。结果表明，方法对钆铀样品中29种杂质元素，即Al、Ba、Ca、Co、Cr、Cu、Fe、Li、Mg、Mn、Mo、Na、Ni、Ti、Zn、Ta、W、Th、Bi、Pb、Sn、V、In、Ag、B、Cd、Sm、Eu、Dy的测定准确可靠。对于其它杂质含量相当的铀／钆化合物，通过适当的处理和转化，也可采用本方法测定。     

模拟高放废液玻璃固化体的偏硼酸锂熔融法

一、引言随着核能的发展,人们愈来愈关注放射性废物处理工艺的安全问题。对高放废液常采用玻璃固化的处理方法。玻璃固化工艺的研究需要分析化学方面提供玻璃固化体的成份数据,作为评价其性能的重要依据。     

90－19／U模拟高放废物玻璃固化体表面性能的研究

本文对９０－１９／Ｕ模拟高放废物玻璃固化体的表面性能进行了研究。实验结果表明，固化体与水反应会导致固化体表面层的产生，表面层中Ｌｉ、Ｎａ、Ｂ等易溶元素发生贫化，而Ｕ、Ｆｅ、Ｔｉ、Ｍｇ、Ｃａ等元素发生不同程度的富集；随反应程度不同，表面层厚度也不同，且在反应进行至一定程度后，表面层会发生不同程度裂缝和脱落，并产生表面沉积物。     

Quantitative analysis of saindha salt using laser induced breakdown spectroscopy and cross-validation with ICP-MS

Saindha salt is considered to be more advantageous than the other edible salts for the patients suffering from diabetes,blood pressure and kidney diseases.To explore the constituent elements of this salt,laser induced breakdown spectroscopy(LIBS) has been exploited for its qualitative and quantitative analysis.The third harmonic(355 nm) of a Q-switched Nd:YAG laser has been used to produce the saindha salt plasma and the time integrated optical emission spectra were registered using a set of six miniature spectrometers covering the spectral range of 230-805 nm.The spectroscopic analysis of the emission spectra predominately revealed numerous neutral or singly ionized emission lines of Ca,Mg,Na,K,Fe,Sr,Si,Li and Al.The laser produced plasma was characterized by calculating the electron temperature from the Boltzmann plots and the electron number density from the Stark broadened line profile as a function of laser irradiance and distance from the target sample.The relative concentration of the constituent elements was extracted by the integrated line intensities of the strongest spectral line of each element using the self-calibration-LIBS(SC-LIBS) and one-line calibration free-LIBS(OLCF-LIBS) methods.For cross-validation,the LIBS results have been compared with that obtained from the inductively coupled plasma-mass spectroscopy(ICP-MS) showing good agreement.     

Real-time evolution of ion–surface interactions of MgAl2O3 and LiNbO3 detected by ion-induced photon spectroscopy

Ion-induced photon emission under 60 keV Cu⁻ implantation into the insulators of MgAl₂O₄ and LiNbO₃ was in situ measured over a wide wavelength range from 200 to 900 nm. The formation of the Mg and Li deficient layers for the respective insulator was detected based on the dose dependence of the Al, Mg and Li atomic line intensities. The Al I and Mg I line intensities from spinel exhibit different behaviors depending on irradiation temperatures: they gradually decrease while the (Al I)/(Mg I) ratio increases up to dose of 3×10¹⁷ ions/cm² at room temperature or exhibits a steady-state tendency at high temperature. Sharp decrease of Li I line intensity from LiNbO₃ under high dose rate bombardment indicates drastic changes of surface layer that may alter the phase stability and optical performance of insulators.     

Angular dependence from L3-subshell to M-shell vacancy transfer probabilities for heavy elements using EDXRF technique

Angular dependence from L₃-subshell to M-shell vacancy transfer probabilities for selected heavy elements from Au to U have been measured by using a Si(Li) detector coupled to a model 1024 computerized multi-channel analyzer. Because the angular dependence from L₃-subshell to M-shell vacancy transfer probabilities is not found in the literature, to the best of our knowledge there are no experimental values for worked elements. Therefore, the results for the elements obtained in the present study constitute the first experimental measurements; the comparison has been not made with other experimental and theoretical results. It has been observed that angular dependence from L₃-subshell to M-shell vacancy transfer probabilities increase with increasing cos θ.     

Laser-induced plasma generated by a 532nm pulsed laser in bulk water:unexpected line-intensity variation with water temperature and the possible underlying physics

The effect of the matrix temperature on laser-induced plasma generated in bulk water by using a532 nm pulsed laser beam has been studied.Ca Ⅰ and Ⅱ emission line intensities were recorded for an aqueous solution of CaCl_2 in the temperature range of 7℃-70℃.The emission line intensities did not follow the matrix temperature in our experiments.Maximum intensities were observed at ～18℃ for both lines.Herein,a possible mechanism responsible for the observed variation in intensity is suggested,in which laser-produced bubbles play important roles.Bubble formation is essential to ignite plasma in the liquid and more feasible at the higher liquid temperature.However,the abundant bubbles at the higher temperature can scatter the incident laser beam more effectively to decrease the energy delivered for the laser-induced plasma.Thus,these two roles have effects on the optical emission intensities in opposite ways.The validity of the suggested mechanism is discussed based on the plasma temperature,temperature dependence of the refractive index of water,plasma electron density,scattered light intensity,and plasma ignition threshold energy.Our result indicates that the temperature of the liquid is also an important parameter to be considered in the laser-induced breakdown spectroscopy analysis of bulk liquid samples and its application in deep-sea exploration.     

Efficient removal of Co(Ⅱ) from aqueous solution by titanate sodium nanotubes

In this paper,a novel material for Co(Ⅱ)adsorption,titanate sodium nanotubes(Na_2Ti_2O_5-NTs)were synthesized and characterized,and then they were used to remove Co(Ⅱ) from aqueous solution and compared with titanic acid nanotubes(H_2Ti_2O_5-NTs) and potassium hexatitanate whiskers(K_2Ti_6O_(13)).The results showed that the adsorption of Co(Ⅱ) on the materials was dependent on p H values and was a spontaneous,endothermic process.Specifically,Na_2Ti_2O_5-NTs exhibited much more efficient ability to adsorb Co(Ⅱ) from aqueous solution,with the maximum adsorption capacity of 85.25 mg/g.Furthermore,Na_2Ti_2O_5-NTs could selectively adsorb Co(Ⅱ) from aqueous solution containing coexisting ions(Na~+,K~+,Mg~(2+),and Ca~(2+)).The results suggested that Na_2Ti_2O_5-NTs were potential effective adsorbents for removal of Co(Ⅱ) or cobalt-60 from wastewater.     

原子吸收光谱法测定模拟高放废物玻璃固化体浸出液中的元素锂、钠、铁和锶

报道了原子吸收光谱法测定模拟高放废液玻璃固化体浸出液中的钠、锂、铁和锶元素的方法,确定了各元素分析的最佳操作参数,研究了各干扰元素对待分析元素的影响,测定了各待分析元素的回收率(93％-125％)。