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1.
V. I. Grishkovets A. E. Kondratenko N. V. Tolkacheva A. S. Shashkov V. Ya. Chirva 《Chemistry of Natural Compounds》1995,30(6):689-692
The leaves of common ivy have yielded 11 triterpene glycosides: the 3-O--L-pyranosides of oleanolic acid (1), of echinocystic acid (2), and of hederagenin; the 3-O-[O--L-rhamnopyranosyl-(12)--L-arabinopyranoside]s of oleanolic acid (4), of echinocystic acid (5), and of hederagenin (6); the O--L-rhamnopyranosyl-(14)-O--D-glucopyranosyl-(16)-O--D-glucopyranosyl ester of hederagenin 3-O--L-pyranoside (7); the O--D-glucopyranosyl-(16)-O--D-glucopyranosyl ester of hederagenin 3-O-[O--L-pyranosyl-(12)--L-arabinopyranoside] (9); and the O--L-rhamnopyranosyl-(14)-O--D-glucopyranosyl-(16)-O--D-glucopyranosyl esters of oleanolic acid, echinocystic acid, and hederagenin 3-O-[O--L-rhamnopyranosyl-(12)--D-glucopyranoside]s (8), (10), and (11), respectively. This is the first time that compounds (1), (2), (5), (7), (9), and (10) have been found in this plant.Simferopol' State University. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 742–746, November–December, 1994. 相似文献
2.
V. I. Grishkovets A. E. Kondratenko N. V. Tolkacheva A. S. Shashkov V. Ya. Chirva 《Chemistry of Natural Compounds》1994,30(6):689-692
The leaves of common ivy have yielded 11 triterpene glycosides: the 3-O-α-L-pyranosides of oleanolic acid (1), of echinocystic
acid (2), and of hederagenin; the 3-O-[O-α-L-rhamnopyranosyl-(1→2)-α-L-arabinopyranoside]s of oleanolic acid (4), of echinocystic
acid (5), and of hederagenin (6); the O-α-L-rhamnopyranosyl-(1→4)-O-β-D-glucopyranosyl-(1→6)-O-β-D-glucopyranosyl ester of
hederagenin 3-O-α-L-pyranoside (7); the O-β-D-glucopyranosyl-(1→6)-O-β-D-glucopyranosyl ester of hederagenin 3-O-[O-α-L-pyranosyl-(1→2)-α-L-arabinopyranoside]
(9); and the O-α-L-rhamnopyranosyl-(1→4)-O-β-D-glucopyranosyl-(1→6)-O-β-D-glucopyranosyl esters of oleanolic acid, echinocystic
acid, and hederagenin 3-O-[O-α-L-rhamnopyranosyl-(1→2)-β-D-glucopyranoside]s (8), (10), and (11), respectively. This is the
first time that compounds (1), (2), (5), (7), (9), and (10) have been found in this plant.
Simferopol' State University. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 742–746, November–December, 1994. 相似文献
3.
Tolkacheva Anna S. Shkerin Sergey N. Zemlyanoi Kirill G. Reznitskikh Olga G. Pershina Svetlana V. Khavlyuk Pavel D. 《Journal of Thermal Analysis and Calorimetry》2019,136(3):1003-1009
Calcium vanadates Ca5Mg4−xZnx(VO4)6 (0 ≤ x ≤ 4) have been studied for the first time using a set of high-temperature methods of analysis. The onset of melting process determined from differential scanning calorimetry decreases from 1158 to 881 °C (± 1.5 °C) with increasing of x (dopant’s content). CTE temperature dependence is found to show a hysteresis. Electrical transport properties measured by impedance spectroscopy in air of different humidity are also discussed. The value of electrical conductivity does not depend on air humidity. It is found to equal to 1.5 × 10−6 S cm−1 at 720 °C for Ca5Mg4(VO4)6 which is specific for garnet-related crystals.
相似文献4.
5.
S. V. Antonenko M. A. Goryachev S. M. Tolkacheva 《Bulletin of the Russian Academy of Sciences: Physics》2007,71(8):1094-1095
Superconducting YBa2Cu3O7 ? x films were fabricated by dc magnetron sputtering. They were irradiated with 1.2-MeV He+ ions to doses of 4 × 1015, 8 × 1015, 16 × 1015, and 32 × 1015 cm?2. The irradiated films were subjected to stepwise (30 min per step) vacuum annealing at 500, 600, 700, 800, and 900°C. After vacuum annealing, the samples irradiated to doses of 4 × 1015, 8 × 1015, and 16 × 1015 cm?2 exhibited partial recovery of their critical temperature, whereas the sample with a dose of 32 × 1015 cm?2 exhibited no signs of partial recovery of T C. Investigation of the irradiated annealed samples with the Umka nanotechnological complex has revealed damaged surface regions extended to a relatively large (several tenths of a micrometer) depth. 相似文献
6.
The Fenton-Karma model is a simplification of complex ionic models of cardiac membrane that reproduces quantitatively many of the characteristics of heart cells; its behavior is simple enough to be understood analytically. In this paper, a map is derived that approximates the response of the Fenton-Karma model to stimulation in zero spatial dimensions. This map contains some amount of memory, describing the action potential duration as a function of the previous diastolic interval and the previous action potential duration. Results obtained from iteration of the map and numerical simulations of the Fenton-Karma model are in good agreement. In particular, the iterated map admits different types of solutions corresponding to various dynamical behavior of the cardiac cell, such as 1:1 and 2:1 patterns. (c) 2002 American Institute of Physics. 相似文献
7.
N. V. Tolkacheva A. G. Bogdanov A. N. Dmitrieva R. P. Kokoulin V. V. Shutenko 《Bulletin of the Russian Academy of Sciences: Physics》2011,75(3):377-380
We analyze experimental data on cosmic ray muon bundles collected with a DECOR coordinate detector. Substantial variations
in the intensity of the events are observed during the experiment. These variations are found to be caused by changes in atmospheric
conditions. This study is the first to obtain experimental estimates of the temperature and barometric coefficients for muon
bundles. It is shown that the observed effect can be explained by changes in the side distribution function of EAS muons. 相似文献
8.
R. P. Kokoulin A. G. Bogdanov D. M. Gromushkin G. Mannocchi A. A. Petrukhin O. Saavedra N. V. Tolkacheva G. Trinchero D. V. Chernov V. V. Shutenko I. I. Yashin 《Bulletin of the Russian Academy of Sciences: Physics》2011,75(3):395-398
Characteristics of muon bundles detected with the DECOR detector are compared to predictions based on different hadron interaction models and various assumptions as to the spectrum and mass composition of primary cosmic rays. The intensity of primary cosmic rays derived from the muon bundle data is considerably higher than that measured by means of the fluorescence technique. Either changes in the hadron interaction characteristics at ultrahigh energies or a revision of the energy calibration in the fluorescence technique of measuring EAS energy is required to explain these results. 相似文献
9.
A. S. Tolkacheva S. N. Shkerin S. V. Plaksin E. G. Vovkotrub K. M. Bulanin V. A. Kochedykov D. P. Ordinartsev O. I. Gyrdasova N. G. Molchanova 《Russian Journal of Applied Chemistry》2011,84(6):907-911
The nanoporous material mayenite was synthesized by two methods: solid-phase and self-propagating high-temperature (combusting)
(SHS) syntheses. The structure of the materials was determined by the X-ray diffraction analysis and IR and Raman spectroscopy. 相似文献
10.
N. V. Tolkacheva A. G. Bogdanov A. N. Dmitrieva R. P. Kokoulin V. V. Shutenko 《Bulletin of the Lebedev Physics Institute》2010,37(6):173-174
The data of the experimental study of cosmic ray muon groups using the DEKOR setup for the period of 2004–2007, during which
significant changes in the intensity of groups at the Earth’s surface were detected, are analyzed. It was found that these
variations are caused by variations of weather conditions (temperature and atmospheric pressure); barometric and temperature
coefficients were determined. It turned out that magnitudes of these coefficients for muon groups are significantly higher
than available values for singlemuons. Possible physicalmechanismof the effect is discussed. Since muon groups are formed
at high altitudes (of the order of several kilometers), the detected effect can be used for monitoring air temperature variations
in the upper troposphere. 相似文献