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An improved substrate scope for the mechanochemical electrophilic fluorination of dicarbonyls is reported. The applicable substrates have now been broadened to include liquid β-ketoesters. Key to this capability is the inclusion of a grinding auxiliary (NaCl) to improve mass transfer and prevent pasting or gumming of the reaction mixture. Notably, the use of a small amount of acetonitrile is critical to increasing the rate of reaction, ensuring complete consumption of starting materials during the short reaction times as well as improving the selectivity for the monofluorinated product in the mill. 相似文献
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Ivanov Yu. B. Soldatov A. A. Pakhomov A. V. Arkhipov M. V. Rosanov N. N. Arkhipov R. M. Sturman B. Podivilov E. Arbuzov A. Bondarenko S. Dydyshka Ya. Kalinovskaya L. Rumyantsev L. Sadykov R. Yermolchyk V. Yermolchyk Yu. Kats E. I. Shilpashree S. P. Shastri Venkataramana Zakharov B. G. Galakhov V. R. Udintseva M. S. Naumov S. V. Shamin S. N. Gizhevskii B. A. Valba O. Gorsky A. Gavryushkin P. N. Martirosyan N. S. Rashchenko S. V. Sagatova D. N. Sagatov N. E. Semerikova A. I. Fedotenko T. M. Litasov K. D. Avchyan B. R. Ghazaryan A. G. Sargsyan K. A. Sedrakian Kh. V. 《JETP Letters》2022,116(5):342-345
JETP Letters - An Erratum to this paper has been published: https://doi.org/10.1134/S0021364022330013 相似文献
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Yerdos Ongarbayev Ainur Zhambolova Yerbol Tileuberdi Zulkhair Mansurov Cesare Oliviero Rossi Pietro Calandra Bagdat Teltayev 《Molecules (Basel, Switzerland)》2022,27(10)
This paper considers the effect of aging processes on viscoelastic characteristics of vacuum residue oxidation products modified with crumb rubber. Viscoelastic properties were compared to original bitumen raw material-vacuum residue and vacuum residue oxidation products during short-term and long-term aging. The complex shear modulus of the vacuum residue and its oxidation products decreased with an increase in temperature. Short-term aging resulted in increased shear modulus for all samples.The vacuum residue oxidation product modified with crumb rubber had the maximum values of the rutting parameter and fatigue parameter. There was an expansion of the temperature range of plasticity: for the vacuum residue oxidation product with crumb rubber, its value was 67.2 °C. The curves of the black diagram of the modified vacuum residue oxidation product are shifted towards smaller phase angles with the increase in the shear modulus, which indicates the increase in the stiffness and elasticity of the rubber bitumen binders. The vacuum residue oxidation product modified with crumb rubber corresponded to the rubber bitumen binder of the grade RBB 60/90, according to its physical and mechanical indicators. 相似文献
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Nursultan E. Sagatov Pavel N. Gavryushkin Maksim V. Banayev Talgat M. Inerbaev Konstantin D. Litasov 《高压研究》2020,40(2):235-244
ABSTRACTBased on the first-principles calculations within the density functional theory and crystal structure prediction algorithms iron phosphide phases stable under pressure of the Earth’s core and temperatures up to 4000?K were determined. A new low-temperature modification FeP-P21/c stable above ~75?GPa was predicted. Fe2P with the allabogdanite structure has been established to be stable in the low-temperature region at ambient conditions. At 750?K it transforms into the barringerite structure. The transition from Fe3P with schreibersite structure to Fe3P-Cmcm was observed at 27?GPa, and the phase transition boundary is nearly isobaric. Fe2P and FeP are thermodynamically stable at the Earth’s inner core pressures and 0?K according to the obtained results, whereas Fe3P stabilizes with respect to decomposition to Fe?+?Fe2P at high temperatures above ~3200?K. 相似文献
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Yerbol K. Akhmetbekov Sergey V. Alekseenko Vladimir M. Dulin Dmitriy M. Markovich Konstantin S. Pervunin 《Experiments in fluids》2010,48(4):615-629
A correlation-based processing algorithm for bubble identification by a planar fluorescence for bubble imaging (PFBI) technique
is presented in this paper. The algorithm includes procedures to identify bubble positions and sizes, as well as to track
bubbles and correct bubble displacement vectors. Moreover, several schemes for calculation time optimisation were realised
to achieve a reliable calculation time. The developed algorithm identifies and tracks overlapping bubble images or images
with non-uniform intensity distributions. The employed correlation and iterative passing approach provides sub-pixel accuracy
of bubble displacement estimation. In addition, the presented algorithm for bubble ring detection can be easily applied to
shadow photography images of bubbles, after the application of a derivative filter. The PFBI technique, combined with the
particle image velocimetry and particle tracking velocimetry algorithms, was applied for the experimental study of bubbly
free jet two-phase flows at Re = 12,000. Four cases of volumetric gas content in the jet core were studied: 0, 1.2, 2.4 and 4.2%, with the same mean bubble
diameter—0.85 mm. The developed technique measures two-dimensional distributions of instantaneous void fractions, as well
as both gaseous and liquid-phase velocities. Consequently, the mean void fraction and velocity fields and a set of second-order
statistical moments were obtained, including correlations of void fraction and velocity pulsations. It was shown that the
increase in volumetric gas content leads to the suppression of liquid-phase velocity fluctuations in the jet mixing layer. 相似文献
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S. S. Iskhakova A. V. Mikhailin U. Kh. Rasulev Ya. R. Sagatov U. Khasanov 《Journal of Analytical Chemistry》2004,59(1):50-54
The results of the development of a new method and instrument for determining trace narcotics and other abused drugs in extracts of biological samples (urine, blood, and postmortem specimens) from users of the above substances are reported. The method is based on the unique selectivity (up to 105–108 with respect to organic solvents or up to 1010 with respect to simple gases) and high efficiency of the surface ionization of nitrogen-containing organic bases and on the use of the temperature-programmed evaporation of sample molecules from an evaporator to the surface of an ionizer (emitter). This method provides not only the detection of trace substances (for example, opiates and amitriptyline at a picogram level) but also their identification based on the most probable evaporation temperature. 相似文献
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Gavryushkin P. N. Martirosyan N. S. Rashchenko S. V. Sagatova D. N. Sagatov N. E. Semerikova A. I. Fedotenko T. M. Litasov K. D. 《JETP Letters》2022,116(7):477-484
JETP Letters - Mg-carbonate is one of the main carbonates subducting from the Earth’s surface into the mantle and possible reactions of this compound with the main mantle minerals determine... 相似文献
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