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31.
Kichinosuke Hirokawa Shigeru Suzuki Kenji Abiko Hiroshi Kimura Masaoki Oku 《Journal of Electron Spectroscopy and Related Phenomena》1981,24(2):243-253
A method is proposed for semi-quantitative determination of the thickness or composition of a covering layer on a solid by XPS or by micro-AES using neither a series of standard samples nor argon-ion etching. In the case of XPS, the thickness or relative composition of the covering layer is calculated by means of the intensity ratio between one element and another in a specimen and using physical parameters such as inelastic mean free paths of electrons and photoionization cross-sections.In the case of AES, the physical parameters for the quantification can be eliminated by using the ratio of the relative intensity for two elements in the sample to that in a suitable, comparable reference. 相似文献
32.
The thermal decomposition of dialkali metal salts of β- and γ-hydroxyketone tosyl-hydrazones in refluxing DME produced pyrazoles and pyridazines, respectively. 相似文献
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Cyclic and acyclic ethers are regioselectively cleaved at less substituted α-carbon-oxygen bond in the absence of Lewis acid by the reagent system of sodium iodide and acyl chlorides. 相似文献
34.
Quantitative ESCA has been used for studying the surface of mixed precipitates. When the precipitation is complete and homogeneous, as with titanium and zirconium hydroxides, almost complete correlation is found between the atomic ratio of the elements in the precipitate and that estimated by the Hirokawa-Ebel method, but not for incomplete mixed precipitation, as with copper and silver hydroxides. When precipitated copper and silver are reduced to the metals with iron or zinc, the surface is enriched in copper. 相似文献
35.
Oku N Krishnamoorthy R Benson AG Ferguson RL Lipton MA Phillips LR Gustafson KR McMahon JB 《The Journal of organic chemistry》2005,70(17):6842-6847
The absolute stereochemistry of the three unresolved structural components in neamphamide A (1) was determined to be (R)-beta-methoxy-L-tyrosine, (2R,3R,4S)-4-amino-7-guanidino-2,3-dihydroxyheptanoic acid, and (2R,3R,4R)-3-hydroxy-2,4,6-trimethylheptanoic acid. Stereochemical assignments were made by chemical degradation of 1, derivatization of the resulting products, and then spectroscopic and chromatographic comparison of the derivatives with synthetically prepared standards. Using the same analytical protocol developed for 1, the beta-methoxytyrosine residue in papuamide B (2) was found to be (R)-beta-methoxy-D-tyrosine. This represents a rare example of divergent stereochemistry in an unusual amino acid residue that is present in two closely related classes of peptides. 相似文献
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Shimada T Kondoh H Iwasaki M Nakai I Nagasaka M Amemiya K Orita H Ohta T 《The journal of physical chemistry. B》2006,110(41):20507-20512
The adsorption structure of NO on the reconstructed Pt(110)-(1 x 2) surface was studied with X-ray photoelectron spectroscopy (XPS), X-ray photoelectron diffraction (XPD), low-energy scanned-angle photoelectron diffraction (LESA-PD), and near-edge X-ray absorption fine structure (NEXAFS) spectroscopy. The experiments were performed at 180 K, where no surface lifting from (1 x 2) to (1 x 1) takes place after NO adsorption. XPS indicates that the (1 x 2) unit cell of the Pt(110) surface contains 1.5 NO molecules at the saturated coverage. XPD and LESA-PD analyses allow us to propose a structural model for the NO adlayer, where two-thirds of the NO molecules in the (1 x 2) unit cell are adsorbed on the atop site of the close-packed Pt rows (ridges) along the [10] direction with an inclined geometry and one-third of the NO molecules adsorb on the bridge site between the Pt ridges with an upright configuration. This model is supported by the N K-edge NEXAFS experiments and is consistent with the recently reported model based on the density functional theory (Orita, H.; Nakamura, I.; Fujitani, T. J. Phys. Chem. B 2005, 109, 10312). 相似文献
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Physics of the Solid State - Transition metal doped cesium lead halide (CsPbI3) perovskite compounds were studied for application in photovoltaic solar cells. Electronic structures, chemical shifts... 相似文献