Иноязычная коммуникативная компетенция современного преподавателя технического вуза

В статье рассматриваются организационно-педагогические и методические условия формирования иноязычной коммуникативной компетенции преподавателя технического вуза на примере реализации программы повышения квалификации "Формирование профессиональной дидактической компетенции средствами английского языка". Иностранный язык становится инструментом для выполнения профессиональной деятельности современного преподавателя технического вуза

Lithium and oxygen adsorption at the b-MnO2 (110) surface

The adsorption and co-adsorption of lithium and oxygen at the surface of rutile-like manganese dioxide(b-MnO2), which are important in the context of Li–air batteries, are investigated using density functional theory. In the absence of lithium, the most stable surface of b-MnO2, the (110), adsorbs oxygen in the form of peroxo groups bridging between two manganese cations. Conversely, in the absence of excess oxygen, lithium atoms adsorb on the (110) surface at two different sites, which are both tricoordinated to surface oxygen anions, and the adsorption always involves the transfer of one electron from the adatom to one of the five-coordinated manganese cations at the surface, creating (formally) Li+ and Mn3+ species. The co-adsorption of lithium and oxygen leads to the formation of a surface oxide, involving the dissociation of the O2 molecule, where the O adatoms saturate the coordination of surface Mn cations and also bind to the Li adatoms. This process is energetically more favourable than the formation of gas-phase lithium peroxide (Li2O2) monomers, but less favourable than the formation of Li2O2 bulk. These results suggest that the presence of b-MnO2 in the cathode of a nonaqueous Li–O2 battery lowers the energy for the initial reduction of oxygen during cell discharge

Amorphisation and recrystallisation study of lithium intercalation into TiO 2 nano-architecture.

Titanium dioxide is playing an increasingly significant role in easing environmental and energy concerns. Its rich variety of polymorphic crystal structures has facilitated a wide range of applications such as photo-catalysis, photo-splitting of water, photoelectrochromic devices, insulators in metal oxide, semiconductors devices, dye sensitized solar cells (DSSCs) (energy conversions), rechargeable lithium batteries (electrochemical storage). The complex structural aspects in nano TiO 2 , are elucidated by microscopic visualization and quantification of the microstructure for electrode materials, since cell performance and various aging mechanisms depend strongly on the appearance and changes in the microstructure. Recent studies on MnO 2 have demonstrated that amorphisation and recrystallisation simulation method can adequately generate various nanostructures, for Li-ion battery compounds. The method was also previously employed to produce nano-TiO 2 . In the current study, the approach is used to study lithiated nanoporous structure for TiO 2 which have been extensively studied experimentally, as mentioned above. Molecular graphic images showing microstructural features, including voids and channels have accommodated lithium’s during lithiation and delithiation. Preliminary lithiation of TiO 2 will be considered

Structures, electronic properties, and delithiation thermodynamics of the heteroepitaxial α-Al2O3//LiMn2O4 (001) and (111) interfaces

Surface coatings play a pivotal role in enhancing the performance of secondary lithium-ion batteries by mitigating undesirable electrolyte activity towards the cathode materials. Metal oxide candidates have been investigated extensively, with α-Al2O3 emerging as a particularly promising coating material owing to its exceptional mechanical and thermal stability alongside low electrical conductivity. Despite the extensive exploration of this application of α-Al2O3, insight into the interplay between the coating layer and the cathode substrate remains incomplete. To address this lack of knowledge, this study employs density functional theory calculations with a Hubbard Hamiltonian and long-range dispersion corrections (DFT+U-D3) to comprehensively investigate the interfacial geometries, stabilities, and electronic properties of α-Al2O3-coated LiMn2O4 (001) and (111) interfaces of varying thicknesses. The individual surfaces were modelled first before constructing the interfaces. We found that the α-Al2O3 (112¯0) and (0001) surfaces match the LiMn2O4 (001) and (111) facets well, exhibiting {1132} and {3121} configurations, respectively, with corresponding misfits of 2.40 and 2.75 %. We calculated the largest adhesion energies of 0.16 and 0.10 eV/Å2 for monolayers with the {1132} and {3121} configurations, respectively, with the stability decreasing as the thickness of the α-Al2O3 layer increases. Further analysis reveals a minor charge accumulation on the substrate, attributed to charge accumulation on the oxygen atoms that participate in the Al-O bond. In contrast, we observed a depletion of charge on the manganese atoms that form the MnO6 units. The vacancy formation energies increase following partial delithiation, prompting minor charge depletion on neighbouring Mn atoms in the form of charge redistribution. The calculated work function increases with respect to the pristine surfaces, indicating that the coated interfaces are less reactive

Interatomic potential parameters for Li-Cl-Ti interaction

Alkali metals and alkali earth metals can be used as reducing agents of titanium halide in titanium production. Despite South Africa’s position as being the major raw titanium material producer, titanium production is low and expensive as a direct consequence of the outmoded technology that is used in its extraction from raw materials such as the Kroll process. In this study, computational modelling techniques were employed to simulate the conditions for LiCl that will be suitable for generating a large quantity of metallic titanium in pure and powder form. We used a combination of density functional theory and molecular dynamics, employing FHI-aims, DL_POLY and GULP to characterize LiCl in a solid and molten form. The derived potentials reproduced the LiCl structure to within 1% in agreement with experimental data. More importantly, the melting temperature was deduced from the diffusion coefficient as 800 K which is closer to the experimental melting point of 878 K. Furthermore, the interaction of Ti-Li, Ti-Cl and Li-Cl-Ti were tested and gave reasonable results to set an environment for titanium clusters. The new pair potentials were deduced as Ti-Cl: De=0.400 a0= 1.279 r0=2.680 and Ti-Li: De =0.730 a0=1.717 r0=2.000. The findings of this work will contribute towards the development of alternative ways of titanium production in a continuous and less expensive processes

Increased Regulatory T-Cell Activity and Enhanced T-Cell Homeostatic Signaling in Slow Progressing HIV-infected Children

Pediatric slow progressors (PSP) are rare ART-naïve, HIV-infected children who maintain high CD4 T-cell counts and low immune activation despite persistently high viral loads. Using a well-defined cohort of PSP, we investigated the role of regulatory T-cells (TREG) and of IL-7 homeostatic signaling in maintaining normal-for-age CD4 counts in these individuals. Compared to children with progressive disease, PSP had greater absolute numbers of TREG, skewed toward functionally suppressive phenotypes. As with immune activation, overall T-cell proliferation was lower in PSP, but was uniquely higher in central memory TREG (CM TREG), indicating active engagement of this subset. Furthermore, PSP secreted higher levels of the immunosuppressive cytokine IL-10 than children who progressed. The frequency of suppressive TREG, CM TREG proliferation, and IL-10 production were all lower in PSP who go on to progress at a later time-point, supporting the importance of an active TREG response in preventing disease progression. In addition, we find that IL-7 homeostatic signaling is enhanced in PSP, both through preserved surface IL-7receptor (CD127) expression on central memory T-cells and increased plasma levels of soluble IL-7receptor, which enhances the bioactivity of IL-7. Combined analysis, using a LASSO modeling approach, indicates that both TREG activity and homeostatic T-cell signaling make independent contributions to the preservation of CD4 T-cells in HIV-infected children. Together, these data demonstrate that maintenance of normal-for-age CD4 counts in PSP is an active process, which requires both suppression of immune activation through functional TREG, and enhanced T-cell homeostatic signaling

Structure and properties of ilmenite from first principles

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