ФИЗИКО-ХИМИЧЕСКИЕ АСПЕКТЫ ПОЛУЧЕНИЯ ПОРОШКА ВОЛЬФРАМА МЕТАЛЛОТЕРМИЕЙ ШЕЕЛИТОВОГО КОНЦЕНТРАТА В ИОННЫХ РАСПЛАВАХ

Preparation conditions of tungsten powder by the decomposition of the scheelite concentrate in the medium of NaCl–Na2CO3, NaCl– Na2CO3–NaF, and NaCl–Na2CO3–Na3AlF6 salt melts and reduction of formed sodium tungstate with aluminum at 1123–1273 K are investigated. It is established that the powder yield is ~93 wt.%, the of tungsten is 97 %. Granulometric characteristics of powders are determined. It is shown that the specific surface of powders reaches 14,6·105 m–1. Изучены условия получения порошка вольфрама разложением шеелитового концентрата в среде солевых расплавов NaCl–Na2CO3, NaCl–Na2CO3–NaF, NaCl–Na2CO3–Na3AlF6 и восстановлением образующегося вольфрамата натрия алю- минием при температуре 1123–1273 К. Установлено, что выход порошка составляет ~93 мас.%, чистота вольфрама – 97 %. Определены гранулометрические характеристики порошков. Показано, что удельная поверхность порошков достигает величины 14,6·105 м–1.

Angular dependence of the coherent peak position in the polarization bremsstrahlung spectrum of relativistic electrons in polycrystalline targets

The spectra of the polarization bremsstrahlung (PB) in the X-ray range induced by 7-MeV electrons in polycrystalline Al, Cu, and Ni polycrystalline films have been measured and the angular dependences of the PB characteristics have been studiedyesBelgorod State Universit

Modification of the EDXD method for diagnostics of polycrystalline and fine-grained media

The possibilities of using broadband X rays for diagnostics of the atomic structure of solids are considered. It is proposed to use virtual photons of the Coulomb field of a relativistic electron beam as primary probe radiationye

Ion-beam sputtering of NiO hole transporting layers for p-i-n halide perovskite solar cells

Ion-beam sputtering offers significant benefits in terms of deposition uniformity and pinhole-free thin-films without limiting the scalability of the process. In this work, the reactive ion-beam sputtering of nickel oxide has been developed for the hole transporting layer of a p-i-n perovskite solar cells (PCSs). The process is carried out by oxidation of the scattered Ni particles with additional post-treatment annealing regimes. Using deposition rate of 1.2 nm/min allowed growth of very uniform NiO coating with the roughness below 0.5 nm on polished Si wafer (15x15 cm2). We performed a complex investigation of structural, optical, surface and electrical properties of the NiO thin-films. The post-treatment annealing (150-300C) was considered as an essential process for improvement of the optical transparency, decrease of defects concentration and gain of the charge carrier mobility. As result, the annealed ion-beam sputtered NiO films delivered a power conversion efficiency (PCE) up to 20.14%, while device without post-treatment reached the value of 11.84%. The improvement of the output performance originated from an increase of the short-circuit current density (Jsc), open circuit voltage (Voc), shunt and contact properties in the devices. We also demonstrate that the ion-beam sputtering of NiO can be successfully implemented for the fabrication of large area modules (54.5 cm2) and PSCs on a flexible plastic substrate (125 microns)

Modification of the EDXD Method for Diagnostics of Polycrystalline and Fine-Grained Media

Abstract -The possibilities of using broadband X rays for diagnostics of the atomic structure of solids are considered. It is proposed to use virtual photons of the Coulomb field of a relativistic electron beam as primary probe radiation

Malat1 RNA genetic factor and T1 bladder cancer

In this study, we collected overview data regarding the possible association of rs 3200401 polymorphism of the MALAT1 gene in patients with a single focus and multifocal bladder cancer stage T

ПОЛУЧЕНИЕ ЛЕГИРОВАННЫХ НИКЕЛИДОВ АЛЮМИНИЯ МЕТАЛЛОТЕРМИЕЙ ОКСИДОВ МЕТАЛЛОВ

Fabrication conditions of NiAl, NiAl–Cr and NiAl–Cr–Mo–W alloys by joint aluminothermic reduction of initial metal oxides are investigated. Thermodynamic characteristics of accompanying reactions are determined. The temperature dependence of the isobaric potential change (ΔG0, kJ/mol) of reduction reactions of oxides point to high formation probability of alloys. It is revealed by differential thermal analysis that the reduction of metal oxides enters the active phase after aluminum is melted at ~650 °C and progresses according to the heterogeneous mechanism in a temperature range of 800–1100 °C. The optimal composition of the initial charge, which provides the maximal yield of metals into alloys, is established. It is found experimentally that the yield of metals into alloys constitutes 85–92 wt.%. Synthesis products are identified by the elemental and X-ray phase analyses as intermetallic compounds of the Ni–Al system, which contain inclusions of chromium, molybdenum, and tungsten. It is shown that the concentration of inclusions varies in a range of 1,5–6,5 wt.%. The microhardness of alloys is determined to vary from 3546 to 7436 MPa depending on the content of alloying elements.Изучены условия получения интерметаллидных сплавов NiAl, NiAl–Cr, NiAl–Cr–Mo–W совместным алюминотермическим восстановлением исходных оксидов металлов. Определены термодинамические характеристики протекающих при этом реакций. Температурная зависимость изменения изобарного потенциала (ΔG0, кДж/моль) реакций восстановления оксидов указывает на высокую вероятность образования сплавов. Методом дифференциального термического анализа выявлено, что восстановление оксидов металлов вступает в активную фазу после расплавления алюминия при ~650 °С и протекает по гетерогенному механизму в интервале температур 800–1100 °С. Установлен оптимальный состав исходной шихты, обеспечивающий максимальный выход металлов в сплавы. Экспериментально найдено, что выход металлов в сплавы составляет 85–92 мас.%. Продукты синтеза идентифицированы элементным и рентгенофазовым методами анализа как интерметаллиды системы NiAl, содержащие включения хрома, молибдена, вольфрама. Показано, что концентрация включений варьируется в пределах 1,5–6,5 мас.%. Определена микротвердость сплавов, которая изменяется от 3546 до 7436 МПа в зависимости от содержания легирующих элементов

REDUCING SMELTING OF CASSITERITE CONCENTRATE IN AN IONIC MELT

The features of coal chemical recovery cassiterite concentrate in molten salt system Na2Co3–NaNO3  (1:0,3) were studied. It is shown that cassiterite (SnO2) in the salt melt (900–950 °C) proceeds in the form metastannate (Na2SnO3) and reduced to the metal, mainly gas CO, with high speed and completeness (97%)