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101.
Inna V. Melnyk Vasyl P. Goncharyk Natalia V. Stolyarchuk Lidia I. Kozhara Anna S. Lunochkina Bruno Alonso Yuriy L. Zub 《Journal of Porous Materials》2012,19(5):579-585
The sorption properties towards dysprosium(III) ions of three samples of mesoporous silicas functionalized with phosphonic groups????Si(CH2)2P(O)(OH)2 were studied. It was found that for the sample synthesized by spray-drying using OTAB as a template both sorption and desorption rate of Dy3+ ions is high, due to the defined porosity of the sorbent. Sorption of Dy3+ ions by bridged silsesquioxane xerogels with disordered structure is significantly hindered by diffusion processes, due to the chaotic packing of globules. Using a model for the chemical reactions, the composition of dysprosium(III) complexes with surface phosphonic groups were determined, and their formation constants were calculated. It was shown that xerogels with higher surface concentration of ligand groups (L), can form complexes DyL3 and DyL4 ?. Meanwhile, the sample synthesized by spray-drying method forms only DyL2 + and DyL3 complexes. For this sample, complexes DyL3 are more stable than for xerogels. So, mesoporous silica derived by spray-drying method, with defined spatial porosity and relatively low surface concentration complexation groups, is characterized by the best sorption properties towards dysprosium(III) (adsorption and desorption kinetics, the value of the static sorption capacity). 相似文献
102.
The shape memory behavior of [111]-oriented Ni_(51)Ti_(49) (at.%) single crystals was investigated after stressassisted aging at 500 °C for 1.5 h under a compressive stress of-150 MPa.It was found that a single family of Ni_4Ti_3 precipitates with two crystallographically equivalent variants was formed after aging under compressive stress.Stressassisted aging resulted in tensile two-way shape memory effect strain of 1.56% under-5 MPa.Thermal cycling under-600 MPa resulted in a transformation strain of-2.15%,while the subsequent thermal cycling under-5 MPa resulted in a tensile two-way shape memory effect strain of 2.2%. 相似文献
103.
Andrey O. Zhigachev Vyacheslav V. Rodaev Alexey V. Umrikhin Yuriy I. Golovin 《Ceramics International》2019,45(1):627-633
The present study was aimed at investigating the effect of silica impurities on structure and mechanical properties of zirconia ceramics, stabilized in tetragonal phase by addition of 6.5?mol% calcia. The effect of silica was studied in 0–5?mol% silica concentration range. It was shown that notable increase in fracture toughness (from 7.5?MPa?m0.5 to 12.5?MPa?m0.5) as well as limited rise in hardness (from 12?GPa to 13?GPa) can be achieved by addition of ~ 2.5?mol% of SiO2. It was shown that further increase in SiO2 concentration above 3.75?mol% results in destabilization of tetragonal phase and degradation of mechanical properties. It is suggested that silica reacts with calcia resulting in formation of amorphous calcium silicate, decreasing calcia content in zirconia matrix, and facilitates sintering and grain growth, resulting in lower stability of tetragonal phase. 相似文献
104.
105.
Alena Y. Drobiazko Anastasia A. Kasimova Peter V. Evseev Mikhail M. Shneider Evgeniy I. Klimuk Alexander S. Shashkov Andrei S. Dmitrenok Alexander O. Chizhov Pavel V. Slukin Yuriy P. Skryabin Nikolay V. Volozhantsev Konstantin A. Miroshnikov Yuriy A. Knirel Anastasia V. Popova 《International journal of molecular sciences》2022,23(9)
In this study, several different depolymerases encoded in the prophage regions of Acinetobacter baumannii genomes have been bioinformatically predicted and recombinantly produced. The identified depolymerases possessed multi-domain structures and were identical or closely homologous to various proteins encoded in other A. baumannii genomes. This means that prophage-derived depolymerases are widespread, and different bacterial genomes can be the source of proteins with polysaccharide-degrading activities. For two depolymerases, the specificity to capsular polysaccharides (CPSs) of A. baumannii belonging to K1 and K92 capsular types (K types) was determined. The data obtained showed that the prophage-derived depolymerases were glycosidases that cleaved the A. baumannii CPSs by the hydrolytic mechanism to yield monomers and oligomers of the K units. The recombinant proteins with established enzymatic activity significantly reduced the mortality of Galleria mellonella larvae infected with A. baumannii of K1 and K92 capsular types. Therefore, these enzymes can be considered as suitable candidates for the development of new antibacterials against corresponding A. baumannii K types. 相似文献
106.
Alexander V. Prygun Yevhenii M. Morozov Tatiana Yu Kliuieva Yuriy A. Borodin 《Journal of Modern Optics》2013,60(16):1688-1694
ABSTRACTIn this paper, we present experimental results on speckle noise suppression using a completely passive method. The passivity of the method is achieved owing to the absence of any mechanical, electronic, or other dynamic influences on the optical scheme elements. In the experiment, a multimode semiconductor 520?±?5-nm laser with a spectral bandwidth of 2?nm, static two-dimensional (2D) and 2?×?1D diffractive optical elements (DOEs), as well as multimode single-core optical fibre and multimode optical fibre bundle were used. The dependence of the speckle reduction efficiency as a function of the optical fibre type and optical fibre length was measured for different DOEs. A speckle contrast of 0.148 and speckle reduction coefficient of 2.38 were obtained for a 2.5-m-long multimode optical fibre bundle. The experimental results confirmed that it is possible to construct completely passive optical circuits with reduced speckle noises using static multimode optical fibres and diffraction optical elements. 相似文献
107.
Schubert O Becker J Carbone L Khalavka Y Provalska T Zins I Sönnichsen C 《Nano letters》2008,8(8):2345-2350
We study the wavelength and polarization dependent plasmon resonances of single silver and gold nanorods, triangles, cubes, and dimers with a novel single particle spectroscopy method (RotPOL). In RotPOL, a rotating wedge-shaped polarizer encodes the full polarization information of each particle within one image. This reveals the symmetry of the particles and their plasmon modes, allows analyzing inhomogeneous samples and the monitoring of particle shape changes during growth in situ. 相似文献
108.
Maria Konoshenko Yuriy Lansukhay Sergey Krasilnikov Pavel Laktionov 《International journal of molecular sciences》2022,23(14)
Background: Platinum-based chemotherapy, cisplatin (DDP) specifically, is the main strategy for treating lung cancer (LC). However, currently, there is a lack of predictive drug-resistance markers, and there is increased interest in the development of a reliable and sensitive panels of markers for DDP chemotherapy-effectiveness prediction. MicroRNAs represent a perspective pool of markers for chemotherapy effectiveness. Objectives: Data on miRNAs associated with LC DDP chemotherapy response are summarized and analyzed. Materials and methods: A comprehensive review of the data in the literature and an analysis of bioinformatics resources were performed. The gene targets of miRNAs, as well as their reciprocal relationships with miRNAs, were studied using several databases. Results and Discussion: The complex analysis of bioinformatics resources and the literature indicated that the expressions of 12 miRNAs have a high predictive potential for LC DDP chemotherapy responses. The obtained information was discussed from the point of view of the main mechanisms of LC chemoresistance. Conclusions: An overview of the published data and bioinformatics resources, with respect to the predictive microRNA markers of chemotherapy response, is presented in this review. The selected microRNAs and gene panel have a high potential for predicting LC DDP sensitiveness or DDP resistance as well as for the development of a DDP co-therapy. 相似文献
109.
Dr. Yuriy Dedkov 《真空研究与实践》2014,26(3):19-25
Graphene is an intriguing object of condensed mater physics. Discovery of its fascinating transport properties renewed the interest to the studies of graphene on metallic surfaces. That leads to the technological breakthrough showing that graphene on metals can be used as a protective layer and that its synthesis on metals is the most promising way to prepare huge graphene layers. However, all technology‐related and fundamental studies of the graphene‐metal interfaces require the understanding of the bonding mechanism at the interface and the consequent modifications of the electronic structure of graphene compared to the free‐standing case. Here we consider two representative examples of the strongly and weakly bonded graphene on metals demonstrating how surface science methods help to understand the origin of the bonding at the graphene‐metal interface. These methods help to trace all modifications in the electronic structure of graphene on the microscopic and macroscopic levels. 相似文献
110.
Olga Madelen Ingrid Todoshchenko Yuriy Yagodzinskyy Tapio Saukkonen Hannu Hänninen 《Metallurgical and Materials Transactions A》2014,45(11):4742-4747
High-strength carbon steels of 1200 MPa strength level with different microalloying were tensile tested at constant extension rate and constant load under continuous electrochemical hydrogen charging. The results show that hydrogen markedly reduces elongation and time to fracture of all the studied steels. Fractography of the steels shows that nonmetallic inclusions (NMIs) play the major role in crack initiation in hydrogen-charged specimens. The role of NMIs in the hydrogen-induced fracture of steels is discussed. 相似文献