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JPC – Journal of Planar Chromatography – Modern TLC - Separations of eight methyl esters of higher fatty acids on RP-18 stationary phase with methanol—water and... 相似文献
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Monolinuron, chlortoluron, diuron, isoproturon, linuron, diflubenzuron, dimefuron, teflubenzuron, and lufenuron have been chromatographed on an RP-HPLC column and on RP-HPTLC plates with methanol–water in different volume proportions as mobile phases. The retention values log k, and RM were extrapolated to zero methanol content. Chromatographic lipophilicities (log kw, RMw, o(HPLC), and o (TLC)) were compared with measured (log Pexp) partition coefficients and with values (A log Ps, IA log P, C log P, log PKowin, and x log P) calculated by use of five different software products. The most significant correlations were found between the chromatographic lipophilicities and C log P values. Satisfactory linear correlation was also obtained between lipophilicity (log kw, RMw) and the valence Gutman index (M). 相似文献
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The normalized Born approximation has been suggested as a ratiometric method in fluorescence molecular tomography (FMT) applications, to account for heterogeneity variations. The method enabled practical inversions, as it offered fluorescence reconstruction accuracy over a wide range of absorption heterogeneity, while also accounting for unknown experimental factors, such as the various system gains and losses. Yet it was noted that scattering variations affect the robustness and accuracy. Herein we decompose the effects of absorption and scattering and capitalize on the recent development of hybrid FMT/x-ray computed tomography imaging methods to proposed amendments to the method, which improve the overall accuracy of the approach. 相似文献
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JPC – Journal of Planar Chromatography – Modern TLC - Fatty acids from pentanoic to tricosanoic have been separated on RP-18 HPTLC plates, with and without concentrating zone, with... 相似文献
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JPC – Journal of Planar Chromatography – Modern TLC - The chromatographic behavior of the phenolic drugs niclosamide, hexachlorophene, ibuprofen, pentazocine, ethamivan, bithionol,... 相似文献
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JPC – Journal of Planar Chromatography – Modern TLC - Nicotinic acid (NAC) and its derivatives methyl nicotinate (MN), ethyl nicotinate (EN), isopropyl nicotinate (IPN), butyl... 相似文献
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N. Pyka L. Pintschovius A. Yu. Rumiantsev 《Zeitschrift für Physik B Condensed Matter》1991,82(2):177-181
The magnetic excitations in La2CuO4 and La1.9Sr0.1CuO4 were studied by inelastic neutron scattering up to energies of 76 meV. For the pure sample, the results forE15 meV can be well described by conventional spin wave theory with a spin wave velocity c=0.89±0.07 eVÅ. For lower energies, the observed intensities were somewhat higher than expected from spin wave theory and did not follow the Bose-Einstein factor. For the doped sample, the linewidth in constant-E scans at smallE shows a very short correlation length of =7.5 Å only, which is considerably below the value expected from the concentration dependence reported by other authors. An increase of the linewidth for largeE indicates a reduced spin-wave stiffness when compared to the undoped material. However, the use of a spin-wave picture may not be appropriate as the standard expression for damped spin waves in a paramagnetic material is in serious conflict with experiment. 相似文献