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31.
Piotr Potera Ireneusz Stefaniuk Marian Kuzma Ihor Virt Barbara Pukowska 《Central European Journal of Physics》2009,7(2):299-303
In the present work, a CdTe alloy doped with a relatively high concentration of chromium (1%), and a CdTe:Cr layer, have been
studied. Absorption and reflectivity spectra were measured at room temperature. They indicate the presence of chromium in
the divalent state, both in the alloy and in the layer.
相似文献
32.
Sesegma Dorzhieva Ihor Chumak Angelina Sarapulova Daria Mikhailova Jibzema Bazarova Helmut Ehrenberg 《Acta Crystallographica. Section C, Structural Chemistry》2011,67(10):i50-i52
In the present tetragonal modification of dysprosium orthomolybdate, Dy2(MoO4)3, the Dy, one Mo and one O atom are located on a mirror plane with Wyckoff symbol 4e, while another Mo atom is located on a fourfold inverse axis, Wyckoff symbol 2a. A single crystal was selected from a polycrystalline mixture of the Dy2O3–ZrO2–MoO3 system and was stable at room temperature for at least three months. The structure refinement does not indicate the presence of Zr on the Dy sites (to within 1% accuracy). Thus, the stabilization of the tetragonal form is due to disordered positions for a second O atom and split positions for a third O atom that also maintain the DyO7 coordination, which is not expected for short Dy—O distances [2.243 (6)–2.393 (5) Å]. 相似文献
33.
Galyna Volynets Hanna Vyshniakova Georgiana Nitulescu George Mihai Nitulescu Anca Ungurianu Denisa Margina Olena Moshynets Volodymyr Bdzhola Ihor Koleiev Olga Iungin Sergiy Tarnavskiy Sergiy Yarmoluk 《Molecules (Basel, Switzerland)》2021,26(23)
Staphylococcus aureus (S. aureus) is a causative agent of many hospital- and community-acquired infections with the tendency to develop resistance to all known antibiotics. Therefore, the development of novel antistaphylococcal agents is of urgent need. Sortase A is considered a promising molecular target for the development of antistaphylococcal agents. The main aim of this study was to identify novel sortase A inhibitors. In order to find novel antistaphylococcal agents, we performed phenotypic screening of a library containing 15512 compounds against S. aureus ATCC43300. The molecular docking of hits was performed using the DOCK program and 10 compounds were selected for in vitro enzymatic activity inhibition assay. Two inhibitors were identified, N,N-diethyl-N′-(5-nitro-2-(quinazolin-2-yl)phenyl)propane-1,3-diamine (1) and acridin-9-yl-(1H-benzoimidazol-5-yl)-amine (2), which decrease sortase A activity with IC50 values of 160.3 µM and 207.01 µM, respectively. It was found that compounds 1 and 2 possess antibacterial activity toward 29 tested multidrug resistant S. aureus strains with MIC values ranging from 78.12 to 312.5 mg/L. These compounds can be used for further structural optimization and biological research. 相似文献
34.
Ihor Charischak 《School science and mathematics》2000,100(7):349-354
In last month's issue of School Science and Mathematics, Glenda Lappan addressed the dilemma of supporting teachers in continuing to grow professionally in four domains: Learning more mathematics content; improving their pedagogical skills; improving assessment skills; and addapting the curriculum to the needs of their students. Though it is clear that this kind of learning is best done in the context of what is going on in the classroom, teachers' schedules and other problems make it difficult to implement a coherent classroom based, professional development program. In this article, two more knowledge domains are added to this mix: the ability to (a) use technology and (b) teach with technology effectively. Since the process of learning and teaching is a dynamic one, the author describes his vision of the classroom as a laboratory where teachers get to practice and improve in these six areas and get feedback from an audience of their peers. Reflections are based on a current project in Paterson, New Jersey where the author helps middle school teachers use computer software to improve their mathematics teaching and learning. 相似文献
35.
ABSTRACT We discuss the role of non-hydrodynamic processes in viscoelastic transition in pure liquids. In particular, using both analytical results and molecular dynamics simulations, we clarify the effect of the shear stress relaxation on the transverse dynamics. We use as an example the Lennard-Jones fluids. We analyse the frequency dependence of the shear modulus and its connection to the non-hydrodynamic shear relaxation mode. The analysis of the relaxation times of the non-hydrodynamic modes in longitudinal and transverse dynamics makes evidence that the emergence of the non-hydrodynamic transverse excitations outside the propagation gap is not directly connected to the onset of the positive sound dispersion. 相似文献
36.
Ihor Chumak Klaus W. Richter Helmut Ehrenberg 《Acta Crystallographica. Section C, Structural Chemistry》2010,66(9):i87-i88
The crystal structure of iron dialuminide [Corby & Black (1973). Acta Cryst. B 29 , 2669–2677] has been redetermined on a single crystal synthesized from the elements by arc melting. The compound crystallizes in the triclinic space group P with 19 atoms per unit cell, one Fe site being on an inversion centre. The crystal structure can be described as an inclusion‐plus‐deformation derivative of the orthorhombic YPd2Si structure type. 相似文献
37.
Ihor Tarnavchyk Andriy Voronov Ananiy Kohut Nataliya Nosova Serhiy Varvarenko Volodymyr Samaryk Stanislav Voronov 《Macromolecular rapid communications》2009,30(18):1564-1569
In this study, highly stable gold and silver nanoparticles evenly distributed within a crosslinked poly(acrylamide)/poly(N‐(hydroxymethyl)acrylamide) (PAAm‐PHMAAm) network have been fabricated without addition of a reducing agent. Remarkably, the same chemical hydrogel composition has been involved in the successful fabrication of spherical gold and silver nanoparticles within the hydrogel template. The hydrogel network acts simultaneously as an efficient reducing agent and stabilizer. The PAAm–PHMAAm hydrogel network binds metal ions and, following reduction of bound to crosslinked template metal ions, proceeds via oxidation of hydroxymethyl hydrogel fragments. A one‐electron mechanism is proposed for the formation of the silver and gold nanoparticles.
38.
Aleksandra Wdrychowicz Bogumi Cieniek Ireneusz Stefaniuk Ihor Virt Romana
liwa 《Molecules (Basel, Switzerland)》2022,27(14)
The magnetic properties of lead selenide (PbSe) and indium-doped lead telluride (PbTe:In) composites have been studied by using the electron paramagnetic resonance (EPR) technique. The samples were obtained by using the pulsed laser deposition method (PLD). Temperature dependences of the EPR spectra were obtained. The analysis of the temperature dependencies of the integral intensity of the EPR spectra was performed using the Curie–Weiss law. In these materials, the paramagnetic centers of Pb1+ and Pb3+ ions were identified. The results are discussed. 相似文献
39.
Taras O. Banakh Fedor A. Bogomolov Andrij I. Gatalevych Ihor J. Guran Yurij B. Ishchuk Mykola Ya. Komarnytskyi Igor S. Kuz Ivanna O. Melnyk Vasyl M. Petrychkovych Yaroslav G. Prytula Oleh M. Romaniv Oleh B. Skaskiv Ludmyla L. Stakhiv Georgiy T. Sullym Bohdan V. Zabavskyi Volodymir P. Zelisko Mykhajlo M. Zarichnyi 《Central European Journal of Mathematics》2013,11(9):1547-1551
40.
Volodymyr Pavlyuk Grygoriy Dmytriv Ivan Tarasiuk Ihor Chumak Helmut Ehrenberg 《Acta Crystallographica. Section C, Structural Chemistry》2011,67(12):i59-i62
New ternary dodecalithium dodecacopper tetradecaaluminium, Li12Cu12.60Al14.37 (trigonal, Rm, hR39), crystallizes as a new structure type and belongs to the structural family that derives from binary Laves phases. The Li atoms are enclosed in 15‐ and 16‐vertex and the Al3 atom in 14‐vertex pseudo‐Frank–Kasper polyhedra. The polyhedra around the statistical mixtures of (Cu,Al)1 and (Al,Cu)2 are distorted icosahedra. The electronic structure was calculated by the TB–LMTO–ASA (tight‐binding linear muffin‐tin orbital atomic spheres approximation) method. The electron localization function, which indicates bond formation, is mostly located at the Al atoms. Thus, Al—Al bonding is much stronger than Li—Al or Cu—Al bonding. This indicates that, besides metallic bonding which is dominant in this compound, weak covalent Al—Al interactions also exist. 相似文献