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排序方式: 共有593条查询结果,搜索用时 15 毫秒
1.
Varfolomeev S. D. Panin A. A. Semenova N. A. Ublinskiy M. V. Akhadov T. A. Bykov V. I. Tsybenova S. B. 《Russian Chemical Bulletin》2022,71(3):591-594
A kinetic study of the effect of thermoheliox (inhalation of a helium and oxygen mixture, 70 °C) on the functional hemodynamics of the human brain by functional magnetic resonance imaging was carried out. The dynamic responses of the BOLD signal were found to be biphasic. An empirical equation describing the first phase of the hemodynamic response to visual stimulus was proposed. It was shown that preliminary inhalation of thermoheliox stimulates the hemodynamic responses by slowing down the vasoconstriction.
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A.D. Bykov V.N. Saveliev C. Camy-Peyret A. Valentin 《Journal of Molecular Spectroscopy》2004,224(2):164-175
Forty-seven N2 broadened water vapor line-widths have been measured in the 1845-2140 cm−1 spectral range with a Fourier Transform spectrometer in the 258-330 K temperature range at a spectral resolution of 0.005 cm−1 for the lines with upper state rotational quantum number up to 16. The measured exponents of the temperature dependence of the width exhibit a large range of values from 1.60 to −0.86. Theoretical calculations were made using a semi-empirical technique based on the Anderson theory. The calculated broadening coefficients as well as the temperature exponents for the half-width agree satisfactory with measured values. 相似文献
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Khar'kov Institute of Radio Electronics. Translated from Izvestiya Vysshykh Uchebnykh Zavedenii, Radiofizika, Vol. 34, No. 5, pp. 607–610, May, 1991. 相似文献
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A simple method for evaluating the correction for the effect of solvent on the dipole moments of molecules, determined using the Debye method of dilute solutions, is proposed. 相似文献
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A. F. Bykov P. P. Semyannikov I. K. Igumenov 《Journal of Thermal Analysis and Calorimetry》1992,38(6):1463-1475
The processes of thermal destruction of copper(II) bis(dipivaloylmethanate) (Cu(dpm)2) in the temperature range 150°–550°C were studied by using a two-temperature variant of a double chamber Knudsen cell, with mass spectrometric recording of the gas-phase composition. The temperature range of stability of the vapour of the complex in vacuum was determined, as were those of its mixtures with oxygen in different proportions. The temperature dependence of the rate constant of the thermolysis of (Cu(dpm)2) vapour was obtained. The thermal stability of Hdpm vapour and the influence of oxygen on the thermolysis of the ligand were studied.
Zusammenfassung Unter Verwendung einer Zweitemperaturenvariante der Knudsenschen Doppelkammerzelle wurde mittels MS-Untersuchung der Gasphasenzusammensetzung im Temperaturbereich 150°–550°C der thermische Abbau von Kupfer(II)-bis(dipivaloylmethanat) (Cu(dpm)2) untersucht. Es wurde der Temperaturbereich für die Stabilität der gasförmigen Komplexe in Vakuum sowie in Gemischen mit Sauerstoff in verschiedenen Verhältnissen bestimmt. Dabei wurde die Temperaturabhängigkeit der Geschwindigkeitskonstante für die Thermolyse von Cu(dpm)2 ermittelt. Weiterhin wurde die thermische Stabilität von Hdpm-Dampf sowie der Einfluß von Sauerstoff auf die Thermolyse der Liganden bestimmt.相似文献
8.
Intramolecular cyclization reactions of 3,4-bis(indol-3-yl)maleimides 1, 3-(indol-1-yl)-4-(indol-3-yl)maleimides 2, and 3,4-bis(indol-1-yl)maleimides 3 under the action of protic acids were studied in order to estimate the parameters of the interaction between protonated and
unprotonated indole moieties. Geometric parameters, charge distributions, energy characteristics, and information concerning
the frontier orbitals of bisindolylmaleimides 1–3 were obtained from density functional B3LYP/6-31G(d) quantum chemical calculations. Alternative pathways of protonation of
bisindolylmaleimides with differently bonded indole and maleimide moieties were studied and pathways of cyclization of corresponding
conjugated acids leading to polyannelated compounds were analyzed. All the key intermediates of the cyclization reactions
correspond to stationary points on the potential energy surfaces (minima and transition states). Analysis of the potential
energy surfaces revealed almost linear dependences of the activation energies of the cyclization reactions under study on
the distances between the reaction centers, on the angle of approach of intramolecular electrophile, and on the energy gap
(energy difference between frontier orbitals). The key role in the cyclization reactions is played by structural similarity
between the starting indoleninium cations and the activated complexes of the reactions under study.
Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 754–760, May, 2006. 相似文献
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