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91.
Furans may be ring opened via pallado-catalyzed reactions leading to α,β-unsaturated aldehydes and ketones tethered to indole and isoquinoline moieties. Besides their synthetic interest, these fragmentations bring interesting elements into the discussion around the reaction mechanisms involved in palladium C-H activations of electron-rich heterocycles. 相似文献
92.
We investigate the mixed joint discrete value distribution and the mixed joint discrete universality for the pair consisting of a rather general form of zeta-function with an Euler product and a periodic Hurwitz zeta-function with transcendental parameter. The common differences of relevant arithmetic progressions are not necessarily the same. Also some generalizations are given. For this purpose, certain arithmetic conditions on the common differences are used.
相似文献93.
J. Bukowski R. Kański M. Kańska 《Journal of Radioanalytical and Nuclear Chemistry》2002,254(3):613-618
The kinetic isotope effect (KIE) was applied in the study of the mechanism of bromine elimination from p-methyl-erythro-a,b-dibromocinnamic acid, successively labeled at the a and b carbons. The large 14C KIE for the b-position and small KIE for the a one of side chain of p-methyl-erythro-a,b-dibromocinamic acid proves that elimination of bromine leading to the formation of (E)-p-methylcinnamic acid proceeds via the E1 mechanism. 相似文献
94.
The original experimental device for studying the radial dependences of emitted radiation, generated by the cylindrically
symmetric positive column of the DC glow discharge, is proposed. Principle of detection of the radial intensity profiles of
the spectral lines by means of the special scanner with two movable conic mirrors is described. The function of the scanner
was verified experimentally and by the method of raytracing. As an example, the radial profiles of lines emitted by the positive
column of the neon glow discharge are presented. No significant changes were found.
This work is a part of the research plan MSM 0021620834, that is financed by the Ministry of Education of the Czech Republic. 相似文献
95.
96.
E. Gerlic J. Ka¨llne H. Langevin-Joliot J. Van de Wiele G. Duhamel 《Physics letters. [Part B]》1975,57(4):338-340
Energy spectra have been measured for the (τ, α) reaction at 205 MeV on90Zr, 118,124Sn and 208Pb. Results on the valence neutron shells and on the inner 1f7/2 shell in 90Zr, 1g9/2 subshell in 118,124Sn (T< and T> components) and 1h11/2 subshell in 208Pb are presented. 相似文献
97.
V. Kažukauskas 《Applied Physics A: Materials Science & Processing》1995,60(5):509-514
We report the investigation of the Photo-Magneto-Electric effect (PME) in semi-insulating Liquid-Encapsulated (LEC-) grown GaAs crystals, using both intrinsic and impurity excitation. The role of the majority and minority carriers on the conductivity phenomena was evaluated and the lifetimes of electrons and holes were determined depending on excitation conditions. Anomalously high PME voltages, reaching in some cases some volts, were measured, which demonstrate a sharp drop in the temperature region 320–360K. The observed changes are discussed supposing that the influence of the non-homogeneous defect structure of the samples is essential. 相似文献
98.
Ewa Skrzypczak-Jankun Andrzej Hoser Elżbieta Grzesiak Zygmunt Kałuski Maria D. Rozwadowska 《Journal of chemical crystallography》1979,9(5):233-244
Both of the title compounds crystallize in the monoclinic system: C23H17NO2 (Ib),P21/c,a = 8.970(1),b = 22.629(5),c = 9.101(1) Å, = 106.08(1) °,Z = 4,D
x
= 1.27 Mg m–3; C19H17NO2 (Ic),P21/a,a = 15.225(2),b = 6.429(1),c = 17.190(1) Å, = 112.99(1) °,Z = 4,D
x
= 1.25 Mg m–3. The structures were solved and refined by standard methods, both toR 0.04. In compound Ib, a weak intramolecular interaction is observed between the nitrogen atom from the isoquinoline ring and the carbon atom from the carbonyl group, with the N(2) . C(18)distance being 2.98 Å. In compound Ic, the PhCO2 -fragment is twisted in the opposite direction to that in compound Ib, without hydrogen bonding. The pK
a
and IR data were considered in the light of the results of the X-ray investigation. 相似文献
99.
100.