EDS X-Ray Investigation of Interdiffusion in Au–Ni Micro- and Nanolayers

The interdiffusion process in thin and thick (500nm–60µm) Au–Ni layers deposited on different substrates is studied using the EDS technique. In-depth X-ray analysis based on the Pouchou and Pichoir method is applied for obtaining the concentration profiles in nanometre scale multi-layers. A theoretical analysis using the Darken method is employed for modelling interdiffusion in the Au–Ni system. Computer simulations, where intrinsic diffusivities of the Au and Ni are functions of composition, are presented and compared with experimental results.     

有机化合物中硫元素的微量库仑分析

含硫有机化合物在竖式石英燃烧管中,于氧气流下经950℃高温燃烧分解,生成的二氧化硫(或三氧化硫)通过含双氧水的石英棉转化管,转化为硫酸。硫酸泵入电解池后,进行酸-碱库仑滴定。本法操作按时间程序控制进行,每次分析时间为15分钟,分析绝对误差为±0.5％对含磷的有机硫化合物及含钠、铁、铜、钼、镍、镧等金属的有机硫化合物,如在样品上复盖一层三氧化钨进行燃烧分解,也可获得满意的结果。     

Analytical,structural and electrical characterization of SiGe layers by electron microbeam techniques

k-ratios of Ge-L and Si-K measured at different beam energies allow to evaluate simultaneously composition and thickness of SiGe layers on a Si substrate. A simple technique applying backscattered electrons also enables estimation of composition of bulk SiGe and of composition and thickness of relatively thick (200 nm) SiGe layers on Si. Electron channeling patterns of pseudomorphic SiGe/Si structures and of pure Si substrate show no significant differences whereas in relaxed structures a smearing of the pattern with increasing density of misfit dislocations is observed. Under particular conditions the technique of the electron beam induced current permits imaging of recombination-active misfit dislocations with a spatial resolution around 0.2 m. Moreover, a repulsion of holes due to the valence-band offset in a n-Si/SiGe heterostructure was detected.     

Diffuse-reflectance Fourier transform-infrared spectroscopic microanalysis of the flavonolignans

Diffuse-reflectance Fourier transform-infrared spectroscopic (DRIFT) microanalysis (10 g samples) of a selected series of flavonoids was studied, comparing to transmission FT-IR spectroscopic analysis of the same samples at the mg level. DRIFT was shown to be a useful, sample-saving and reliable IR technique for the structural analysis and compound identification of the mainSilybum genus 3-OH-flavonolignans (silybin, isosilybin, silydianin, silychristin and isosilychristin) and the dihydroflavonol taxifolin.     

Design and Application of a Set of Vitreous Standards for EDS-SEM Microanalysis of Melting Shop Slags

Non-metallic inclusions in steel are formed due to interactions between liquid steel and its environment in the melting shop (refractories and slags). Particles not trapped in the slag remain in the cast steel, impairing steel properties in service. Inclusion composition varies and certified standards covering the whole compositional range are unavailable.The present study describes the preparation of a set of homogeneous, glassy and crystalline standards with a wide compositional range for use in analysing non-metallic steel inclusions. For this, materials were designed based on knowledge of the compositional range of interest in the Al₂O₃–SiO₂–CaO–MgO–CaF₂ system, which is the matrix of the most frequent steel inclusions. The composition and microstructural homogeneity of the reference materials was verified.     

The secondary X-ray fluorescence and absorption near the interface of multi-material: Case of EDS microanalysis

A simple model is proposed to take into account secondary X-ray fluorescence and absorption effects near the interface. This model is based on the investigation of the shape change of the first derivative equation that can fit the sigmoidal EDS profile obtained when a high vacuum electron beam passes through the interface of two adjacent materials. The contribution of the photoelectric absorption of primary X-rays (characteristic and Bremsstrahlung) and the secondary fluorescence on the degradation of the X-ray spatial resolution can be easily quantified. The close agreement between the simulated (Monte Carlo simulation using the Casino software) and the experimental data serves to assess the reliability of this developed model.     

Screening of aromatase inhibitors in traditional Chinese medicines by electrophoretically mediated microanalysis in a partially filled capillary

An electrophoretically mediated microanalysis method with partial filling technique was developed for screening aromatase inhibitors in traditional Chinese medicine. The in‐capillary enzymatic reaction was performed in 20 mM sodium phosphate buffer (pH 7.4), and sodium phosphate buffer (20 mM, pH 8.0) was used as a background electrolyte. A long plug of coenzyme reduced β‐nicotinamide adenine dinucleotide 2′‐phosphate hydrate dissolved in the reaction buffer was hydrodynamically injected into a fused silica capillary followed by the injection of reaction buffer, enzyme, and substrate solution. The reaction was initiated with a voltage of 5 kV applied to the capillary for 40 s. The voltage was turned off for 20 min to increase the product amount and again turned on at a constant voltage of 20 kV to separate all the components. Direct detection was performed at 260 nm. The enzyme activity was directly assayed by measuring the peak area of the produced β‐nicotinamide adenine dinucleotide phosphate and the decreased peak area indicated the aromatase inhibition. Using the Lineweaver–Burk equation, the Michaelis–Menten constant was calculated to be 50 ± 4.5 nM. The method was applied to the screening of aromatase inhibitors from 15 natural products. Seven compounds were found to have potent AR inhibitory activity.     

Synthesis of Some Additives and Study Effect of Gas Oil Composition on Flow Properties

Nine additives were prepared by esterification of dibasic acid (succinic, adipic, sebacic acid) and polyethylene glycol (Mol.wt.=600, 1000, 4000). These additives were characterized by infrared spectral analysis, average molecular weight and polydispersity index. Their influence on the depression of pour point for two type of paraffin gas oils (G1 and G2) were investigated, blends of paraffin gas oils G1 and G2 by different ratio, when their untreated and treated by additives were evaluated as pour point depressant in comparison with the original paraffin gas oils G1 and G2.

The effect of additive type and gas oil composition on wax crystal modification were studied using the photo micrographic analysis. Diethoxylate (eo=182) sebacate with blend gas oil No. 3 has achieved the best performance as pour point depressant. The photo micrographic analysis showed that, the wax morphology was greatly modified to fine dispersed crystals of compact size. A correlation between the pour point depression and the extent of wax modification was detected.     

Manganese-enhanced magnetic resonance microscopy of mineralization

Paramagnetic manganese (II) can be employed as a calcium surrogate to sensitize magnetic resonance microscopy (MRM) to the processing of calcium during bone formation. At high doses, osteoblasts can take up sufficient quantities of manganese, resulting in marked changes in water proton T(1), T(2) and magnetization transfer ratio values compared to those for untreated cells. Accordingly, inductively coupled plasma mass spectrometry (ICP-MS) results confirm that the manganese content of treated cell pellets was 10-fold higher than that for untreated cell pellets. To establish that manganese is processed like calcium and deposited as bone, calvaria from the skull of embryonic chicks were grown in culture medium supplemented with 1 mM MnCl(2) and 3 mM CaCl(2). A banding pattern of high and low T(2) values, consistent with mineral deposits with high and low levels of manganese, was observed radiating from the calvarial ridge. The results of ICP-MS studies confirm that manganese-treated calvaria take up increasing amounts of manganese with time in culture. Finally, elemental mapping studies with electron probe microanalysis confirmed local variations in the manganese content of bone newly deposited on the calvarial surface. This is the first reported use of manganese-enhanced MRM to study the process whereby calcium is taken up by osteoblasts cells and deposited as bone.