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31.
D. V. Belykh M. V. Mal’shakova M. G. Korochkina V. E. Kataev A. V. Kuchin 《Chemistry of Natural Compounds》2011,47(4):612-614
Acylation by suberic acid chloride of chlorin with two oximated isosteviol groups on its periphery produced for the first
time a macrocyclic system containing a porphyrin ring and two tetracyclic ent-beyerane frameworks. 相似文献
32.
33.
V. S. Mal’kov D. A. Kokova A. S. Knyazev T. I. Izaak D. V. Nepomnyashchikh L. N. Kurina 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2011,85(4):690-694
A procedure for the purification of aqueous glyoxal (obtained by the partial oxidation of glycol) from carboxylic acids was
described. Mono- and dibasic organic acids can be removed from solution without any substantial losses of glyoxal by using
weakly basic EDE-10P and AN-31 anionites. A mechanism of the adsorption of carboxylic acids on weak resins was suggested based
on the IR spectra recorded in a study of AN-31 anion-exchange resin. Using this method of purification also allowed the removal
of the glyoxal condensation products from solution. 相似文献
34.
35.
I. Ya. Aref’eva R. V. Gorbachev M. V. Mal’tsev P. B. Medvedev 《Proceedings of the Steklov Institute of Mathematics》2009,265(1):63-74
We clarify the relationship between Schnabl’s solution and pure gauge configurations. Both Schnabl’s and pure gauge solutions are obtained by means of an iterative procedure. We show that the pure gauge string field configuration that is used in the construction of a perturbation series for Schnabl’s solution diverges on a large subspace of string configurations, but it can be rendered convergent by adding a compensating term. The additional term ensures the fulfillment of the equations of motion in a weak sense. This compensating term coincides with the term necessary for obtaining an action consistent with Sen’s first conjecture. 相似文献
36.
We consider the problem of separate detection and filtration of a flow of pulsed signals. We assume that statistically independent
pulsed signals of different shape and random amplitude appear randomly against the background of noise. An algorithm for estimation
of the detection probability of each signal is obtained. Recurrent expressions for thea posteriori probability density of each signal are found. The results of numerical simulation of the proposed algorithms of signal processing
are presented.
Lobachevsky State University of Nizhny Novgorod Russia. Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Radiofizika,
Vol. 42, No. 1, pp. 92–100, January, 1999. 相似文献
37.
Russian Journal of General Chemistry - Effect of out-of-plane screwing of the porphyrin macrocycle (H2P) by means of tetra-meso-substitution and intracyclic N-substitution on the state of NH bonds... 相似文献
38.
39.
In subnormal glow discharge under d.c. excitation at different pressure in a varying transverse magnetic field (0 to 30 G)
some measurements have been carried out for various initial average tube currents. The voltage across the discharge increases
and average tube current and residual current decreases in the magnetic field. With the help of Beckman’s expression [4] for
the axial field and the electron density distribution in a transverse magnetic field the observed variation of current and
voltage can be satisfactorily explained. The variation of axial electric field with transverse magnetic field can be represented
to a fair degree of accuracy by the derived equation. The behaviour of residual current with magnetic field has been observed
in these oscillations. 相似文献
40.
T. Jaravel O. Dounia Q. Malé O. Vermorel 《Proceedings of the Combustion Institute》2021,38(3):3529-3536
In the context of vapour cloud explosion, the flame acceleration process can lead to conditions promoting deflagration to detonation transition (DDT), potentially leading to increased damages in accidental scenarios. This study focuses on this phenomenon by performing simulations of detonation reinitiation for fast flames in the Chapman–Jouguet deflagration regime. It is obtained experimentally by the attenuation of an incident detonation by an array of obstacles. A primary objective of the paper is to demonstrate the ability of the numerical model to reproduce the major experimental trends, namely the variation of the reinitiation propensity for different initial pressures and blockage ratios (BRs). Chemical explosive mode analysis (CEMA) is also adapted to the context of this study, in order to identify locally the propagation regime and to provide insights on the reinitiation mechanism. An a priori validation of the CEMA methodology is first performed on relevant canonical one-dimensional configurations. Subsequently, ensembles of five realizations are computed at different initial pressures and BRs and compared to experimental data. They are shown to reproduce the major observed trends in terms of detonation reinitiation length with respect to the operating conditions, with significant variability from one realization to another. In addition, the reinitiation mechanism is also found to be consistent with experimental observations and a previous numerical study of the same configuration. The CEMA methodology adapted to this context is able to identify locally the different propagation regimes, and to track the highly reactive zones that coherently couple with transverse pressure perturbations, leading to the formation of a strongly reacting kernel which eventually triggers the detonation reinitiation. 相似文献