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排序方式: 共有226条查询结果,搜索用时 15 毫秒
91.
Stewart F. Parker Keith Refson Susan M. Tavender Peter Albers Bernd Hannebauer Matthias Janik Arndt Müller Jürgen Martens Martin Watzke Kenneth Shankland Charlotte Leech Heribert Offermanns 《Journal of Raman spectroscopy : JRS》2009,40(6):703-708
The product of the Asinger reaction between elemental sulfur, n‐butylamine and acetophenone is 8‐(n‐butylaminophenylmethyliden)‐1,2,3,4,5,6,7‐heptathiocane which contains a CS7 ring. A combination of infrared, Raman and inelastic neutron scattering spectroscopies with periodic density functional theory calculations is used to provide a complete assignment of the vibrational spectra of this unusual species. The similarity between the Raman spectra of the compound and that of elemental sulfur is particularly striking. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
92.
93.
94.
Hans Albers 《Nachrichten aus der Chemie》1987,35(10):1025-1025
95.
Coprecipitation of manganese and iron followed by calcination at temperatures below 500°C results in a new structural phase
for the Mn−Fe−O system: a non-stoichiometric spinel with, in every three unit cells, one metal atom missing. About 57% of
the iron in this spinel has the composition γMnFeO3 which is paramagnetic at room temperature. The remaining 43% of the iron has the composition MnyFe2-yO3 with y∼0.16 which is magnetic at room temperature. 相似文献
96.
This paper reports on the alignment requirements of a scalable multidisc laser with respect to the internal reflection losses of the resonator. Considering the polarization state of the mode, these losses are generated due to a polarization mismatch at the disc surfaces. Measurements of the polarization of the output beam from a laser containing tilted discs were compared with computer simulations. The losses were calculated for resonators containing discs deviating slightly from the ideal orientation in a random manner, in order to predict the alignment requirements for a multidisc system. Results for variable numbers of discs and angular deviations are presented. 相似文献
97.
Patricia E. Simmons Tom Albers Debbie Barco Michelle Barker Ron Beer Cassandra Belton Betty Burris Hal Donovan Pili Dressel Ron Giesler Terri Gipson Neal Gleditsch Marian Heimbouch Lea Heintz Linda Kalinowski Kathy Ketterer Kit Klein Lebee Meehan Diane Miller Donna Northcott Barb Pollman Tom Potter Jeffrey Powell Dan Prater Doug Raney Chris Roman Beryl Rosenthal Brian Schaffer Joe Seidler Laura Sturmfels Mary Stewart Carey Tisdal Carol Valenta Suzanne Walton Ralph Wilke 《School science and mathematics》1998,98(7):354-356
98.
Preparation, testing and characterization of doped TiO2 active in the peroxidation of biomolecules under visible light 总被引:2,自引:0,他引:2
Bacsa R Kiwi J Ohno T Albers P Nadtochenko V 《The journal of physical chemistry. B》2005,109(12):5994-6003
Doped TiO2 samples using different preparative procedures were synthesized using either urea or thiourea leading to N- or S-doped TiO2. Photocatalytic peroxidation and oxidation (mineralization) of phosphatidylethanolamine (PE) lipid with doped TiO2 were carried out under light irradiation lambda > 410 nm. The formation of conjugated double bonds in PE molecules was followed to detect the formation of peroxy radicals (peroxidation index) under light excitation (lambda > 410 nm) when doped TiO2 was used. The kinetics of CO2 production was monitored during the mineralization of PE. Colored TiO2 powders were studied in detail by different and complementary physicochemical techniques. The band gap energies of colored TiO2 were determined by diffuse reflectance spectroscopy (DRS). The visible absorption shoulder of TiO2 was observed to follow Urbach's law. The variation of the transient decay after 354 nm laser pulse excitation does not correlate with the different N- and S-TiO2 doping levels introduced by the addition of urea or thiourea. This suggests that the states (recombination centers or traps) introduced by the doping are not effective in varying the decay kinetics within the nanosecond and microsecond time scale. Elemental analysis shows comparable amounts of S- and N-doping of TiO2 when thiourea is used as dopant. X-ray diffraction reveals no rutile in S-TiO2 samples heated to 600 degrees C, suggesting that the addition of sulfur precludes rutilization during sample crystallization. X-ray photoelectron spectroscopy (XPS) of the S-TiO2 samples confirms the preferential localization of S on the 20 topmost layers of S-TiO2 upon calcination at 500 degrees C for 2 h. 相似文献
99.
100.
Although the analytical literature seems abundant for the determination of metoprolol in human plasma, a method using standard equipment providing a sensitive and simple high-performance liquid chromatographic (HPLC) method for limited blood volume, e.g. where 1 mL of blood in a 1 kg infant equals 70 mL of adult blood volume, has rarely been addressed. Therefore, in 500 microL of plasma, metoprolol was extracted using an internal standard and solid-phase extraction columns. Chromatographic analysis was performed on a Spherisorb C(6) column (5 microm particle size) at ambient temperature and fluorimetric detection with an excitation wavelength of 225 nm, and emission wavelength of 310 nm. The mobile phase [30% acetonitrile and 70% 0.25 m potassium acetate buffer (pH 4)] was pumped with 1 mL/min. Metoprolol recovery was determined at 73.0 +/- 20.5%, and the limit of quantitation was 2.4 ng/mL. Precision values of intra- and inter-assay were below 15.5% and those for accuracy were between 90 and 110%. This method was developed for monitoring and determination of pharmacokinetic parameters of metoprolol in pediatric patients and therefore metoprolol plasma concentrations in a 2-year-old child with ventricular tachycardia are reported. . 相似文献