13 research outputs found
Technologies of self-education in the academic and extracurricular activities
The article presents the study of the process of self-education of students. The authors believe that self-education students could not be viewed as a process independent from the teacher. The aim of the study was the consideration and development of technologies from the stimulation, control and regulation processes of self-education students. For this were used the methods of observation, empirical and expert evaluation, analysis and experience. In the process of the study examined the types of educational technologies, their features, shape, creative tasks, etc. The article presents some experience of using technologies stimulating the process self-education students. The authors hope to attract the attention of colleagues to stimulation and organization of the process of self-education students.Вопреки сложившемуся мнению, самообразование студентов и других категорий, обучающихся в учебном заведении, нельзя рассматривать, как процесс независящий от преподавателя. Целью исследования явилось рассмотрение и создание технологий стимулирования, контроля и регулирования процессов самообразования учащихся. Для этого были использованы методы наблюдение, эмпирический, экспертной оценки, аналитический и опыт. В процессе исследования были изучены типы педагогических технологий, их особенности, формы творческих заданий и т.п. В статье представлен некоторый опыт применения авторских технологий, стимулирующих процесс самообразоания студентов. Авторы пришли к выводу о необходимости совершенствование технологии регламентированного процесса обучения в высшей школе в направлении формирования навыков самообразования и надеются привлечь внимание коллег к организации и стимулированию процесса самообразования среди студентов
Formation of Active Centers of Nickel–Zinc Catalysts Deposited on the Nanodiamond for the Selective Hydrogenation of Phenylacetylene
A study is performed of bimetallic catalysts NiZn/ND with ratios Ni : Zn = 1 : 1 and 1 : 3 prepared by impregnation using detonation nanodiamond (ND) as a support. They were compared with monometallic Ni/ND and Zn/ND. It is shown by nitrogen adsorption/desorption, scanning and transmission electron microscopy that metal deposition does not affect the porous structure or morphology of a support. Coordination of metal precursors on a nanodiamond surface proceeds with the participation of functional groups, as is confirmed by a change in the electrokinetic charge of the surface. The reduction of metal precursors is studied by temperature-programmed reduction and in situ XAFS spectroscopy. In Ni-containing samples, two forms of Ni2+ are found that are bonded differently with the support. ZnO is not reduced in the samples upon treatment with hydrogen at temperatures up to 400°C. The fraction of reduced nickel is determined by analyzing XANES spectra. Virtually full reduction of nickel is observed in a catalyst with a Ni : Zn ratio of 1 : 1 after 4 h of in situ treatment with hydrogen inside a spectrometer cell at 400°C, but not at a Ni : Zn ratio of 1 : 3 under the same conditions. The highest selectivity of styrene formation in the reaction of phenylacetylene hydrogenation throughout the investigated range of temperatures (100–350°С) is ensured by NiZn/ND; NiZn/ND is less active and selective, since ZnO closes the active nickel centers and prevents the adsorption of phenylacetylene
Chlorobenzene hydrodechlorination on bimetallic catalysts prepared by laser electrodispersion of NiPd alloy
NiPd bimetallic systems were for the first time synthesized by laser electrodispersion (LED) of the Ni 77 Pd 23 alloy target followed by the deposition of produced bimetallic particles on a TEM copper grid and alumina granules. Selective area energy-dispersive analysis confirms the bimetallic nature of NiPd particles deposited on a TEM copper grid. Their mean size is 1.0 nm according to TEM. XPS data demonstrate that under deposition on alumina granules (total metal content of 0.005 wt.%), nickel in bimetallic particles nearly completely oxidizes to Ni 2+ species predominantly in the form of aluminate. At the same time major part of palladium (84%) exists in Pd 0 but oxidizes to Pd 2+ (80%) during 6 months storage in air. Both metals are deposited on the external surface of alumina granules and localized in the same areas. In situ reduction of both metals by H 2 in the catalytic cell of XPS spectrometer is hindered. Nickel is not reduced even at 450°C, confirming the formation of NiAlO x , whereas palladium is reduced at higher temperatures compared to a similar monometallic catalyst. Nevertheless, NiPd/Al 2 O 3 catalyst is more efficient in gas-phase chlorobenzene hydrodechlorination at 150-350°C than Ni/Al 2 O 3 and even Pd/Al 2 O 3 , and much more stable. The difference may be caused by the formation of new active sites due to the contact between Pd 0 and NiAlO x -modified support, and the protective action of spinel reacting with HCl by-product. © 2018 IUPAC and De Gruyter.Funding: This work was financially supported by RFBR, Funder Id: 10.13039/501100002261 (grant 16-03-00073) and in part by Institute of Metal Physics in the frame of “Magnit” Program