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1.
A. I. Magunov A. Ya. Faenov I. Yu. Skobelev T. A. Pikuz E. Biémont P. Quinet F. Blasco C. Bonte F. Dorchies T. Caillaud F. Salin C. Stenz 《Journal of Experimental and Theoretical Physics》2002,95(6):998-1005
The satellite structure of 1s2p 1,3 P 1-1s 21 S 0 lines of the He-like argon ion in plasma produced by a 45-fs laser pulse in a gas-jet cluster target is measured with a high spectral resolution. Radiation transitions 2p → 1s from autoionizing states (AISs) are detected for ions ranging from Li-like to F-like. The spectrum observed is theoretically simulated with the use of the spectroscopic data for the AISs of multicharged ions obtained within the multiconfiguration relativistic Hartree-Fock method. Good agreement with experimental data is obtained when the main population channels of these states are taken into account for typical values of cluster-target plasma parameters. 相似文献
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Mingbao Zhang Raymond Reeves Cheng Bi Robert Dally Gaetan Ladouceur William Bullock Jefferson Chin 《Tetrahedron letters》2004,45(27):5229-5231
Three novel, optically active, 6-substituted 2-(aminomethyl)chromans were synthesized from readily available chroman 2-carboxylic acid precursors. These chroman-containing primary amines are useful building blocks for the synthesis of chroman-derived pharmaceutical agents. 相似文献
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The basic features of a chemical measurement 总被引:2,自引:0,他引:2
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In the present work, a new method was established by applying solid-phase extraction (SPE) to preconcentrate and separate polymeric aluminum (Al) and using ICP-AES to determine the polymeric Al, the total monomeric Al, and the total Al in soil extracts, respectively. A modified resin was prepared with impregnated 8-hydroxyquinoline-5-sulfoxinate (HQS) on the anion-exchange resin. It has good recognition ability for Al fractions, compared to the commonly used cation ion-exchange resin, which has a better ability to adsorb cations and a weak ability to recognize detailed Al species. The optimum conditions for Al fractionation sorption, elution and separation and the interference of foreign ions were studied with the prepared resin by continuous column and batch procedures. Monomeric Al was bound to Pyrocathecol Violet (PCV) at pH 6.2, whereas the polymeric Al species did not react with PCV for at least 15 min. Because a stable complex of Al-PCV was not absorbed on the HQS modified resin, the polymeric Al could be preconcentrated on-line by the HQS-modified resin. The adsorbed polymeric Al was eluted with 3 mL of 3 mol L(-1) of HCl, and then detected by ICP-AES. The method has been applied to directly determine polymeric Al in soil extracts with high selectivity as well as a high preconcentration factor. It gives a limit of detection of 0.6 ng mL(-1) with a relative standard deviation of less than 5.7% (n = 5, 0.24 microg mL(-1) Al). 相似文献
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Hong Bi Qianwang Chen Yonglong Zhuang Shenqiang Zhao 《Journal of magnetism and magnetic materials》2006
Molecular magnet {NBu4[Fe Cr(ox)3]}x (NBu4+=tetra(n-buty1) ammonium ion; ox2−=oxalate ion) was synthesized under an applied low magnetic field of 0.3 T in comparison to that synthesized without a field. Their crystallinities, morphologies and magnetic properties were characterized by using the X-ray diffractionmeter, the transmission electron microscope, and a superconducting quantum interference device. It is found that the average size of particles synthesized under the applied field appears larger than that synthesized without a field. Moreover, its crystallinity, morphology and magnetic susceptibility have also been improved. However, its chemical structure and ferromagnetic phase transition temperature Tc do not change. Possible reasons to explain this effect are also discussed. 相似文献
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