Quantitative analysis results of CE-1 X-ray fluorescence spectrometer ground base experiment

As the nearest celestial body to the earth, the moon has become a hot spot again in astronomy field recently. The element analysis is a much important subject in many lunar projects. Remote X-ray spectrometry plays an important role in the geochemical exploration of the solar bodies. Because of th equasi-vacuum atmosphere on the moon, which has no absorption of X-ray, the X-ray fluorescence analysis is an effective way to determine the elemental abundance of lunar surface. The CE-1 X-ray fluorescence spectrometer (CE-1/XFS) aims to map the major elemental compositions on the lunar surface. This paper describes a method for quantitative analysis of elemental compositions. A series of ground base experiments are done to examine the capability of XFS. The obtained results, which show a reasonable agreement with the certified values at a 30% uncertainty level for major elements, are presented.     

铈同位素丰度的精确测定研究

通过用高浓缩同位素１４２Ｃｅ和１４０Ｃｅ配制９种混合样品，精确测定质谱计的系统误差校正系数，来校正用该仪器测定的天然铈的同位素丰度比，从而建立了准确测定铈同位素丰度的质谱分析方法，用这种绝对质谱法测定的铈相对原子质量是１４０１１５７±００００８。该数值已于１９９５年为国际理论与应用化学联合会（ＩＵＰＡＣ）的原子量与同位素丰度委员会所采纳     

Characterization of two series of nitrogen-containing dendrimers by natural abundance 15N NMR

Two series of small generation dendrimers built with phosphorus atoms at each branching point and various types of nitrogen atoms at natural abundance of (15)N within the branches are characterized by a gradient enhanced GHNMQC (gradient hydrogen-nitrogen multiple quantum coherence) (1)H-(15)N NMR technique. The first series contains two types of nitrogen atoms, included in phosphorhydrazone linkages (CH=NNMe-P(S)), whereas the second series contains four types of nitrogen atoms included in azobenzene linkages (Ar-N=N-Ar') in addition to the phosphorhydrazone. The influence of the trans/cis isomerization of the azo bond on the (15)N NMR has also been studied. Despite the low solubility of the azobenzene-containing dendrimers, which renders the detection of some signals difficult, (15)N NMR appears as a very sensitive tool to detect chemical changes in the dendritic structure.     

Synthesis and characterization of peroxo complexes of uranium(VI) with aroylhydrazone ligands

The uranium(VI) peroxo complexes containing aroylhydrazones ligands having composition [UO(O₂)L-L(NO₃)₂]·H₂O (where L-L = Benzoic acid[1-(Furan-2-yl)methylene] hydrazide, Benzoic acid[(thiophene-2-yl)methylene] hydrazide, Benzoic acid[1-(thiophene-2-yl)ethylidene] hydrazide, Benzoic acid(phenylmethylene) hydrazide, Benzoic acid[1-(anisol-3-yl)methylene] hydrazide and Benzoic acid[(p-chlorobenzyl)methylene] hydrazide are reported. The complexes were characterized by various physico-chemical techniques, viz. elemental analysis, molar conductivity, magnetic susceptibility measurements, infra red, electronic, mass spectral and TGA/DTA studies. These studies revealed that complexes are non-electrolytes and diamagnetic in nature. The ligands are bound to metal in a bidentate mode. Thermal analysis results provide conclusive evidence for the presence of water molecules in the complexes. Mass spectra confirm the molecular mass of the complexes. Antifungal activity of complexes revealed enhanced activity of complexes as compared to the corresponding ligands.     

Selectivity of monolithic supports under overloading conditions and their use for separation of human plasma and isolation of low abundance proteins

Human serum albumin (HSA) and immunoglobulin G (IgG) represent over 75% of all proteins present in human plasma. These two proteins frequently interfere with detection, determination and purification of low abundance proteins that can be potential biomarkers and biomarker candidates for various diseases. Some low abundance plasma proteins such as clotting factors and inhibitors are also important therapeutic agents. In this paper, the characterization of ion-exchange monolithic supports under overloading conditions was performed by use of sample displacement chromatography (SDC). If these supports were used for separation of human plasma, the composition of bound and eluted proteins in both anion- and cation-exchange mode is dependent on column loading. Under overloading conditions, the weakly bound proteins such as HSA in anion-exchange and IgG in cation-exchange mode are displaced by stronger binding proteins, and this phenomenon was not dependent on column size. Consequently, small monolithic columns with a column volume of 100 and 200 μL are ideal supports for high-throughput screening in order to develop new methods for separation of complex mixtures, and for sample preparation in proteomic technology.     

应用于碳同位素丰度测量的激光频率刻度系统研究

对应用于激光吸收光谱法碳同位素丰度测量中的激光频率实时刻度系统进行研究. 采用不同自由光谱范围的共焦法布里-珀罗干涉仪对测量过程中的激光扫描频率进行实时测量. 分别采用线性内插法和多项式拟合法对激光频率每次扫描过程中的频率非线性进行分析,通过对4976–4980 cm^-1波段CO₂吸收谱的多次测量平均的实验结果与HITRAN-2008数据库相应的吸收峰数据进行比较,得到两种方法的激光频率刻度精度均可达到10^-4 cm^-1,线性内插法的刻度精度要好于多项式拟合法. 验证了激光频率实时刻度系统在碳同位素丰度测量中应用的可行性.关键词：激光频率实时刻度共焦法布里-珀罗干涉仪同位素丰度测量激光吸收光谱法