Выбор материала фильтра на основе СВС-механокомпозитов для рафинирования кремния

Работа посвящена подбору материала фильтра, получаемого с применением технологий механической активации и самораспространяющегося высокотемпературного синтеза (СВС), а также установлению возможности протекания реакции в режиме СВС между выбранными компонентами.The work is devoted to the selection of the filter material obtained with the use of the technologies of mechanical activation and self-propagating high-temperature synthesis (SHS), as well as the establishment of the possibility of the reaction in the SHS mode between the selected components

Prepared to Accompany the End of Life during Pandemics in Nursing Homes †

Background: The COVID-19 pandemic confronted nursing homes with a variety of challenges to ensure the provision of palliative care for residents. PallPan-Implement aimed to adapt the recommendations of the National Strategy for the Care of Seriously Ill, Dying Adults and their Families in Times of Pandemic (PALLPAN) in such a way that nursing facilities can use and implement them. Methods: Based on 33 PALLPAN recommendations, we developed a questionnaire, conducted a pilot implementation for selected nursing homes, and asked for qualitative feedback. Results: The developed questionnaire contains 22 main questions. A three-stage pilot implementation with an introductory event, processing phase, and evaluation event took place in seven facilities. The facilities evaluated the developed questionnaire as helpful. Feedback from the facilities identified three major categories: (a) requirements for facilities should be realistic to avoid frustration, (b) the creation of a pandemic plan for palliative care only is impractical, (c) measures for the psychosocial support of staff is particularly necessary, but was perceived as difficult to implement. Conclusions: The practical implementation of recommendations requires a concept and material tailored to facilities and areas. The strategy of PallPan Implement developed in this project appears to be target-oriented, well-received, and can be recommended for further implementation

Halogenotrinitromethanes: A Combined Study in the Crystalline and Gaseous Phase and Using Quantum Chemical Methods

Klapoetke TM, Krumm B, Moll R, et al. Halogenotrinitromethanes: A Combined Study in the Crystalline and Gaseous Phase and Using Quantum Chemical Methods. Chemistry - A European Journal. 2014;20(40):12962-12973.The halogenotrinitromethanes FC(NO2)(3) (1), BrC(NO2)(3) (2), and IC(NO2)(3) (3) were synthesized and fully characterized. The molecular structures of 1-3 were determined in the crystalline state by X-ray diffraction, and gasphase structures of 1 and 2 were determined by electron diffraction. The Hal C bond lengths in F, Cl, and Br C(NO2)(3) in the crystalline state are similar to those in the gas phase. The obtained experimental data are interpreted in terms of Natural Bond Orbitals (NBO), Atoms in Molecules (AIM), and Interacting Quantum Atoms (IQA) theories. All halogenotrinitromethanes show various intra- and intermolecular non-bonded interactions. Intramolecular N...O and Hal...O (Hal = F (1), Br (2), I (3)) interactions, both competitors in terms of the orientation of the nitro groups by rotation about the C N bonds, lead to a propeller-type twisting of these groups favoring the mentioned interactions. The origin of the unusually short Hal C bonds is discussed in detail. The results of this study are compared to the molecular structure of CIC (NO2)(3)and the respective interactions therein

Tetranitromethane: A Nightmare of Molecular Flexibility in the Gaseous and Solid States

Vishnevskiy Y, Tikhonov DS, Schwabedissen J, et al. Tetranitromethane: A Nightmare of Molecular Flexibility in the Gaseous and Solid States. ANGEWANDTE CHEMIE-INTERNATIONAL EDITION. 2017;56(32):9619-9623.After numerous attempts over the last seven decades to obtain a structure for the simple, highly symmetric molecule tetranitromethane (C(NO2)(4), TNM) that is consistent with results from diffraction experiments and spectroscopic analysis, the structure has now been determined in the gas phase and the solid state. For the gas phase, a new approach based on a four-dimensional dynamic model for describing the correlated torsional dynamics of the four C-NO2 units was necessary to describe the experimental gas-phase electron diffraction intensities. A model describing a highly disordered high-temperature crystalline phase was also established, and the structure of an ordered low-temperature phase was determined by X-ray diffraction. TNM is a prime example of molecular flexibility, bringing structural methods to the limits of their applicability

Carbonyl Diisocyanate CO(NCO)₂: Synthesis and Structures in Solid State and Gas Phase

A modified synthesis for carbonyl diisocyanate, CO­(NCO)₂, starting from trichloroisocyanuric acid and diphosgene is described. In addition to the previously reported ¹³C NMR resonances, the ¹⁵N NMR shift is determined for the first time. The structure in the solid state was determined by X-ray diffraction (XRD) on <i>in situ</i> grown crystals, that in the gas phase was experimentally determined by electron diffraction (GED) and for single molecules theoretically by quantum-chemical calculations. The structures are compared and discussed with related systems. Quantum-chemical calculations as well as GED and XRD prove <i>syn</i>–<i>syn</i> to be the conformation of lowest energy. In quantum-chemical calculations and GED the presence of a <i>syn</i>–<i>anti</i> conformer was confirmed and the structure of this conformer was determined