Sample preparation procedure for the determination of sulphur and trace metals in oil products by the ICP with a minitorch using emulsions

A quick sample preparation method was used for the determination of sulphur and trace metals in oil and oily products by the ICP with a minitorch. Stable aqueous emulsions of oils and oil products were made by using two kinds of emulsifiers (one with low sulphur content, the other sulfonated). Aqueous standard solutions can be used for the preparation of calibration solutions. The contents of S, Al, Cr, Cu, Fe, Mg, Ni and Pb in aqueous emulsions were determined and the results were in good agreement with the composition of oil standard solutions used for control analysis procedure.     

Pyrolysis chemical ionization mass spectrometry of cellulose ethers

Pyrolysis ammonia chemical ionization (PyCI) mass spectrometry was performed on hy-droxyethyl-, hydroxypropyl-,methyl-, hydroxypropylmethyl-, and ethylhydroxyethyl cel-luloses. The mass peaks in the PyCI mass spectra of these cellulose ethers could be assigned to the ions of pyrolytic dissociation products which form via the [2 + 2 + 2] cycloreversion and the E_i elimination pyrolysis pathway. Structural information about the residual amount of nonderivatized cellulose, the relative chain length distributions of the substituents in hydroxyalkyl celluloses, and the end-capping of hydroxyalkyl substituents by alkyl groups in the mixed cellulose ethers is obtained. Interference of secondary pyrolysis products in the PyCI mass spectra is found to be of minor importance, especially in the lower mass regions. © 1995 John Wiley & Sons, Inc.     

原子力显微术轻敲模式中探针样品接触过程及相位衬度研究

借助简单的有阻尼受迫振子模型，研究了原子力显微术轻敲模式中探针与样品接触时间t_c、样品的表面形变D_z和相位衬度对探针设置高度z_c及样品杨氏模量E_s的依赖关系.结果发现,t_c与D_z均随E_s及z_c的增大而减小，同时探针与样品作用过程伴随很小的能量耗散.对轻敲过程中相移量φ的研究表明，E_s较大的样品有较小的φ，且φ随 关键词： 原子力显微术 轻敲模式 相位衬度     

Absorption spectra and the nature of complexes in the polyvinyl Alcohol-Nickel (II) chloride system

We have used electronic spectroscopy in the 160–1100 nm range to study the polyvinyl alcohol-nickel(II) chloride system. Based on the results obtained, we hypothesize formation of mixed-ligand complexes of the type [Ni(H₂O)_6-nCl_n]^2-n (n = 0, 1,..., 5) in the polyvinyl alcohol matrix. Transformation of the coordination sphere as the NiCl₂ concentration changes is apparent both in the region of the d-d transition bands (350–1100 nm) and in the region of the charge transfer bands (160–250 nm). We propose assigning the absorption bands separated by mathematical treatment to complexes of specific compositions. __________ Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 73, No. 1, pp. 136–138, January–February, 2006.     

Depth profiling of latex blends of fluorinated and fluorine‐free acrylates with laser‐induced secondary mass spectrometry

We explored phase separation and self‐assembly of perfluoroalkyl segments at the surface of polymer films obtained from latices of semifluorinated acrylate copolymers and the corresponding latex blends of nonfluorinated and semifluorinated polyacrylates. With laser‐induced secondary mass spectrometry the fluorine distribution was measured after annealing above the minimum film‐forming temperature of the polymers up to a depth of several micrometers. Depth profiles of a semifluorinated acrylate homopolymer and latex blends thereof with fluorine‐free alkylacrylates with 25, 50, and 75 mol % semifluorinated acrylate as well as a copolymer comprised of alkyl acrylate and semifluorinated acrylate (50/50 mol %) were investigated. In the case of latex blends containing both semifluorinated polyacrylates and fluorine‐free or low‐fluorine polymers, self‐assembly accounted for enrichment of the perfluoroalkyl segments at the surface. Coatings exhibiting low surface energy and having a substantially reduced total fluorine content were obtained. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 360–367, 2003     

Nuclear forward scattering vs. conventional Mössbauer studies of atomically tailored Eu-based materials

With the decrease in size of devices, rapid characterization of nano-devices is an inevitable necessity. It is shown that Mössbauer spectroscopy using synchrotron radiation from the advanced photon source provides such a tool of investigation. Results are presented and compared for conventional Mössbauer and Nuclear Forward Scattering for ¹⁵¹Eu-doped magnesium sulfide as an example, especially at low concentrations.     

Traces of functions with a dominating mixed derivative in ℝ<Superscript>3</Superscript>

We investigate traces of functions, belonging to a class of functions with dominating mixed smoothness in ℝ³, with respect to planes in oblique position. In comparison with the classical theory for isotropic spaces a few new phenomenona occur. We shall present two different approaches. One is based on the use of the Fourier transform and restricted to p = 2. The other one is applicable in the general case of Besov-Lizorkin-Triebel spaces and based on atomic decompositions.     

Simultaneous imaging of the structure and fluorescence of a supramolecular nanostructure formed by the coupling of π‐conjugated polymer chains in the intermolecular interaction

We fabricated a micrometer‐long supramolecular chain in which π‐conjugated polyrotaxane was coupled. A new experimental setup was designed and constructed, and the simultaneous direct imaging of the structure and fluorescent function was achieved. Furthermore, we identified the formation of a polymer intertwined network and observed novel fluorescence due to a long‐range interaction via this intertwined network over a distance of 5 μm or more without quenching over 15 min in the near field. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 801–809, 2006     

Mössbauer, X-ray diffraction and magnetization studies of Fe–Mn–Al–Nb alloys prepared by high energy ball milling

Fe₆₀Mn₁₀Al₂₀Nb₁₀, (Fe₆₀Mn₁₀Al₃₀)₉₅Nb₅ and (Fe₆₀Mn₁₀Al₃₀)₉₀Nb₁₀ ball milled powdered alloys were investigated using X-ray diffraction, Mössbauer spectrometry, thermomagnetic (TGM) and magnetization measurements. We studied the influence of Nb content and of different milling times on the structural and magnetic properties. Two main features can be concluded: (1) the FeAlMn induces a BCC phase whatever the Nb content is, and (2) as both increasing Nb content and milling time give rise to an highly disordered state in conjunction with a decrease of the ferromagnetic behavior.     

聚甲基丙烯酸甲酯掺杂Ce3+的飞秒激光三维信息存储

用飞秒激光(200 fs,1 kHz,800 nm)脉冲在掺杂稀土离子Ce3 的聚甲基丙烯酸甲酯(PMMA)膜中进行了光存储实验研究,包括对样品的吸收光谱、激光照射前后的电子旋转共振(Electron spin resonance,ESR)光谱的测量和讨论。结果表明掺杂稀土离子Ce3 的聚甲基丙烯酸甲酯膜具有较低的写入阈值,有利于高速、并行的三维光存储。实验结果采用传统光学显微镜并行读出。给出了四层存储结果(点间距和层间距分别是4μm和16μm),并讨论了脉冲能量的大小对空腔尺寸的影响,进行高密度存储时,在保证读出信号灰度值足够大的情况下,应选择尽量小的激光脉冲写入能量。实验结果表明这种材料可以应用于三维光信息存储。