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71.
H. Herrmann H.-W Jacobi G. Raabe A. Reese R. Zellner 《Fresenius' Journal of Analytical Chemistry》1996,355(3-4):343-344
Nitrate radical (NO3) reactions with benzene (R-1), toluene (R-2), p-xylene (R-3), p-cresol (R-4) and mesitylene (R-5) have been studied by laser photolysis/long path laser absorption (LP-LPLA) in aqueous solution. Rate constants of k1=(4.0±0.6) 108, k2=(1.2±0.3)109, k3=(1.6±0.1)109, k4= (8.4±2.3)108 and k5=(1.3±0.3)109 lmol-1s-1 were obtained at T=298 K. In addition, reaction rate coefficients for SO-5+Fe2+prod. (R-6) and SO-5+Mn2+prod. (R-7) of k6=(4.3±2.4) 107 lmol-1s-1 and k7=(4.6±1.0)106 lmol-1s-1 (T=298 K, I0) have been obtained by the application of laser photolysis/UV-VIS broadband diode array spectroscopy. A new laser photolysis/UV-long path laser absorption experiment has been applied to study the reaction of the Cl-2 radical anion with dissolved sulfur(IV). For the reactions Cl-2+HSO-32Cl-+H++SO-3 (R-8) and Cl-2+SO2-32Cl-+SO-3 (R-9) rate coefficients of k8=(1.7±0.2)108 lmol-1s-1 (T=298 K, I0) and of k9=(6.2±0.3)107 lmol-1s-1 (T=279 K, I0) were obtained. 相似文献
72.
The intensity of coherent anti-Stokes resonance Raman scattering (CARRS) is calculated taking into account the resonant absorption of laser and anti-Stokes waves and changes in the molecule population. The resonant absorption causes an alteration of the phase of the laser wave leading to a decrease and periodic behaviour of the anti-Stokes intensity. This phase change can be compensated by the choice of a definite wave vector mismatchK, which determines the optimum condition for the CARRS. The optimum angle between the Stokes and the laser propagation direction and the optimum cell length are calculated. The line shape of the CARRS is discussed and used for the explanation of the observed dependence of the CARRS spectra on the laser intensity and the frequency and on the molecule number density. In the case of a O-O excitation the vibrational frequencies of the ground and the excited level are generated simultaneously in the CARRS spectra. 相似文献
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This paper presents a special use of the linear poroelasticity theory to describe tidally induced groundwater oscillations. Two models of oscillation inducing mechanism make use of this theory to predict groundwater level fluctuations. The numerical solutions of both models are presented and compared with well water level measurement obtained in Police Basin, north-east Bohemia. 相似文献
78.
Jürgen Herrmann 《Molecular Crystals and Liquid Crystals》2013,570(7-8):219-224
By direct texture observations under pressure in a diamond anvil cell, the phase behaviour of 80CB and CB00A and their mixtures have been investigated. The maximum pressure (pM) of ocurrence of the smectic A phase (smA) runs through a maximum value as a function of mole fraction, the highest pM being observed at about 2.2 kbar for x(CBOOA)-0.284. 相似文献
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Dr. Jana Franke Dr. Martin Bock Dr. Richard Dehn Dr. Jörg Fohrer Dr. Santosh B. Mhaske Dr. Antonella Migliorini Dr. Argyrios A. Kanakis Dr. Rolf Jansen Dr. Jennifer Herrmann Prof. Dr. Rolf Müller Prof. Dr. Andreas Kirschning 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(11):4272-4284
The total and semi‐synthesis of 13 new macrolactones derived from thuggacin, which is a secondary metabolite from the myxobacterium Sorangium cellulosum, are reported. The thuggacins have attracted much attention due to their strong antibacterial activity, particularly towards Mycobacterium tuberculosis. This study focuses on 1) thuggacin derivatives that cannot equilibrate by transacylation between the three natural thuggacins A–C, 2) the roles of the thiazole ring, and 3) the hexyl side chain at C2. Semi‐synthetic O‐methylation at C17 suppressed the transacylations without a substantial loss of antibacterial activity. Exchanging the C17–C25 side chain for simplified hydrophobic chains led to complete loss of antibacterial activity. Exchange of the thiazole by an oxazole ring or removal of the hexyl side chain at C2 had no substantial effect on the biological properties. 相似文献