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81.
Ivanova M. S. Vishnetskaya M. V. Tomskii K. O. Zainulin S. M. 《Kinetics and Catalysis》2022,63(4):418-421
Kinetics and Catalysis - It has been established that the reactions of sulfur dioxide oxidation and carbon dioxide conversion take place in aqueous suspensions of calcium fluoride at room... 相似文献
82.
Ivoilova A. V. Mikhal’chenko L. V. Tsmokalyuk A. N. Kozitsina A. N. Ivanova A. V. Rusinov V. L. 《Russian Chemical Bulletin》2021,70(6):1099-1108
Russian Chemical Bulletin - The results of studying electrochemical conversions of 7-R-3-X-1,2,4-triazolo[5,1-c][1,2,4]-triazin-4-ones (Triazavirin® and its derivatives) using cyclic... 相似文献
83.
I. V. Kumpanenko A. V. Roshchin N. A. Ivanova I. D. Epinat’ev A. M. Skryl’nikov M. V. Dyubanov T. N. Korneeva 《Russian Journal of Physical Chemistry B, Focus on Physics》2016,10(5):740-747
The selective catalytic reduction (SCR) of nitrogen dioxide in an air flow modeling the exhaust gas from an internal combustion engine is studied. Granulated V2O5 (13.5%)–MnO2 (0.7–1.0%)/Al2O3 powder (AVK-10M catalyst) and ammonia injected into a SCR catalytic cell are used as a heterogeneous catalyst of NO2 reduction and a reducing agent, respectively. If the efficiency of NO2 removal is high enough and satisfies the requirements of the State Sanitary Standards for the maximum permissible concentrations of substances emitted into the atmosphere (\(MP{C_{N{O_2}}}\) = 0.085 mg/m3), the reducing agent (ammonia) is not completely consumed during SCR, so a considerable amount of NH3 can be released into the atmosphere. Therefore, a strict control of both NO2 and unreacted ammonia emissions is needed. The dependences of the concentrations of [NH3] and [NO2] on the [NH3]/[NO2] ratio for the model air flow passed through the AVK-10M granular heterogeneous catalyst are measured. It is found that the maximum degree of removal of NO2 from the air takes place at [NH3]/[NO2] = 1.3. In the conventional process, the concentration of [NO2] drop from 530.00 to 0.07 mg/m3, i.e., below the \(MP{C_{N{O_2}}}\). At the same time, the ammonia concentration increases to [NH3] = 3.4 mg/m3, which becomes 85 times the \(MP{C_{N{O_2}}}\), 0.04 mg/m3. To remove unreacted ammonia from air flows, we developed [P–(SO3 -)2 · Me2+] sulfocationites, where Me are the Cu and/or Ca ions, P is a styrene–divinylbenzene copolymer. It is shown that the concentration of ammonia passed through the adsorption cell filled with a freshly sulfocationite drops below \(MP{C_{N{H_3}}}\) = 0.04 mg/m3. The dependences of the dynamic exchange capacity (DEC) before ammonia breakthrough for the [P–(SO3 -)2 · Cu2+] delta-sulfocationite on the air flow rate, [NH3] concentration, and humidity are measured. The maximum value of the DEC, δ = 59.5 mg/cm3, is observed at an air flow velocity of 2.171 m/s, [NH3] = 0.0035 mg/L, and 75% humidity. To illustrate practical applications of the proposed improved SCR method, it is shown that a 3-L replaceable [P–(SO3 -)2 · Cu2+] sorbent cartridge in a SCR exhaust gas purifier for a car internal combustion engine does not need replacement more frequently than every 50000 km. 相似文献
84.
Results of the investigation into the interaction of internal waves and flows and the elaboration of a relevant mathematical model are reported. It is found in the field experiments that internal waves develop against the background of upwelling, which results in formation of jets causing intrusion velocity fluctuations. The mechanism and mathematical model of this process are proposed. A mathematical model of the suspended matter transport by jets with a wave-modulated trajectory is developed and verified. 相似文献
85.
Preparation of Stereoregular Isotactic Poly(mandelic acid) through Organocatalytic Ring‐Opening Polymerization of a Cyclic O‐Carboxyanhydride 下载免费PDF全文
Dr. Antoine Buchard Dr. David R. Carbery Prof. Matthew G. Davidson Dr. Petya K. Ivanova Dr. Ben J. Jeffery Dr. Gabriele I. Kociok‐Köhn Dr. John P. Lowe 《Angewandte Chemie (International ed. in English)》2014,53(50):13858-13861
Poly(mandelic acid) (PMA) is an aryl analogue of poly(lactic acid) (PLA) and a biodegradable analogue of polystyrene. The preparation of stereoregular PMA was realized using a pyridine/mandelic acid adduct (Py?MA) as an organocatalyst for the ring‐opening polymerization (ROP) of the cyclic O‐carboxyanhydride (manOCA). Polymers with a narrow polydispersity index and excellent molecular‐weight control were prepared at ambient temperature. These highly isotactic chiral polymers exhibit an enhancement of the glass‐transition temperature (Tg) of 15 °C compared to the racemic polymer, suggesting potential future application as high‐performance commodity and biomedical materials. 相似文献
86.
Pozdnyakov A. S. Ivanova A. A. Emel’yanov A. I. Prozorova G. F. 《Russian Chemical Bulletin》2020,69(4):715-720
Russian Chemical Bulletin - New polymer nanocomposites containing silver nanoparticles, stabilized by hydrophilic copolymers of 1-vinyl-1,2,4-triazole with vinylsulfonic acid sodium salt of... 相似文献
87.
Valiullina Z. R. Ivanova N. A. Lobov A. N. Miftakhov M. S. 《Russian Journal of Organic Chemistry》2020,56(11):2043-2047
Russian Journal of Organic Chemistry - Methyl (E)-3-[(4S,5S)-5-acetyl-2,2-dimethyl-1,3-dioxolan-4-yl)]prop-2-enoate obtained from D-ribose eliminates water on storage and transforms into a bicyclic... 相似文献
88.
The effect of pH on the zeta potential of dispersions of individual n-alkanes C23H48 and C28H58 with particle sizes of the order of 100 nm, which were prepared by ultrasonic dispersion without the addition of surfactants, was studied. It is shown that at pH ranged from 4 to 12, the investigated n-alkanes form stable dispersions in water. They are characterized by a high zeta potential varying from ?30 to ?50 mV. The phase transition temperatures (melting point, crystallization temperature, formation of rotator phases) were determined for the dispersions using an optical method.
相似文献89.
Mihail Mihaylov Elena Ivanova Videlina Zdravkova Stanislava Andonova Nikola Drenchev Kristina Chakarova Radoslav Kefirov Rositsa Kukeva Radostina Stoyanova Konstantin Hadjiivanov 《Molecules (Basel, Switzerland)》2022,27(1)
The transition to a hydrogen economy requires the development of cost-effective methods for purifying hydrogen from CO. In this study, we explore the possibilities of Cu/ZSM-5 as an adsorbent for this purpose. Samples obtained by cation exchange from aqueous solution (AE) and solid-state exchange with CuCl (SE) were characterized by in situ EPR and FTIR, H2-TPR, CO-TPD, etc. The AE samples possess mainly isolated Cu2+ cations not adsorbing CO. Reduction generates Cu+ sites demonstrating different affinity to CO, with the strongest centres desorbing CO at about 350 °C. The SE samples have about twice higher Cu/Al ratios, as one H+ is exchanged with one Cu+ cation. Although some of the introduced Cu+ sites are oxidized to Cu2+ upon contact with air, they easily recover their original oxidation state after thermal treatment in vacuum or under inert gas stream. In addition, these Cu+ centres regenerate at relatively low temperatures. It is important that water does not block the CO adsorption sites because of the formation of Cu+(CO)(H2O)x complexes. Dynamic adsorption studies show that Cu/ZSM-5 selectively adsorbs CO in the presence of hydrogen. The results indicate that the SE samples are very perspective materials for purification of H2 from CO. 相似文献
90.
T. I. Ivanova O. V. Frank-Kamenetskaya V. A. Drits M. Kastowsky H. Bradaczek 《Crystal Research and Technology》1995,30(3):367-374
The diffraction pattern simulation of four YBa2Cu3Ox single crystals with inhomogeneous distribution was successfully carried out on the base of the theory of X-ray diffraction by disordered interstratified structures. The specific feature of their two-component irregular mixed-layered structures is the total segregation of layers with various oxygen content that led to the formation of so-called intergrowth structures. The concentration of admixture layers varied from 10 to 40% while oxygen content difference within the crystal ranged from 0.5 to 0.3. In one of the crystals the fluctutations of layer heights corresponded to oxygen variation from 6.2 to 7.0. 相似文献