排序方式: 共有85条查询结果,搜索用时 218 毫秒
71.
Gran Johansson Gran Wendin Kateryna N. Bratus Vitaly S. Shumeiko 《Superlattices and Microstructures》1999,25(5-6):905-914
We present an approach for analysing the dc current in voltage biased quantum superconducting junctions. By separating terms from different n -particle processes, we find that the n -particle current can be mapped on the problem of wave transport through a potential structure with n barriers. We discuss the relation between resonances in such structures and the subgap structures in the current–voltage characteristics. At zero temperature we find, exactly, that only processes creating real excitations contribute to the current. Our results are valid for a general SXS junction, where the X region is an arbitrary nonsuperconducting region described by an energy-dependent transfer matrix. 相似文献
72.
Ana I. Lozano Kateryna Krupa Filipe Ferreira da Silva Paulo Limão-Vieira Francisco Blanco Antonio Muñoz Darryl B. Jones Michael J. Brunger Gustavo García 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2017,71(9):226
We report on an initial investigation into the transport of electrons through a gas cell containing 1 mTorr of gaseous furfural. Results from our Monte Carlo simulation are implicitly checked against those from a corresponding electron transmission measurement. To enable this simulation a self-consistent cross section data base was constructed. This data base is benchmarked through new total cross section measurements which are also described here. In addition, again to facilitate the simulation, our preferred energy loss distribution function is presented and discussed. 相似文献
73.
Dr. Ramón Fraga Kateryna Len Regis Lutzing Dr. Gilles Laverny Dr. Julian Loureiro Prof. Miguel A. Maestro Prof. Natacha Rochel Prof. Enrique Rodriguez-Borges Prof. Antonio Mouriño 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(53):13384-13389
Vitamin D receptor ligands have potential for the treatment of hyperproliferative diseases and disorders related to the immune system. However, hypercalcemic effects limit their therapeutical uses and call for the development of tissue-selective new analogs. We have designed and synthesized the first examples of 1α,25-dihydroxyvitamin D3 analogs bearing an allenic unit attached to the D ring to restrict the side-chain conformational mobility. The triene system was constructed by a Pd0-mediated cyclization/Suzuki-Miyaura cross-coupling process in the presence of an allenic side chain. The allenic moiety was built through an orthoester-Claisen rearrangement of a propargylic alcohol. The biological activity and structure of (22S)-1α,25-dihydroxy-17,20-dien-24-homo-21-nor-vitamin D3 bound to binding domain of the vitamin D receptor, provide information concerning side-chain conformational requirements for biological activity. 相似文献
74.
Potential Analysis - We consider parabolic equations of the form $$ u_{t}-\text{div} \left( |\nabla u|^{p-2}\nabla u+ a(x,t)|\nabla u|^{q-2}\nabla u\right)= 0, a(x,t)\geq 0. $$ In the range $\frac... 相似文献
75.
Christoph J. Behrens Kateryna Zelena Ralf G. Berger 《Applied biochemistry and biotechnology》2016,179(8):1404-1417
Dye-decolorizing peroxidases (DyPs) from Auricularia auricula-judae, Bjerkandera adusta, Pleurotus ostreatus and Marasmius scorodonius (Basidiomycota) were expressed in Escherichia coli using the cold shock-inducible expression system pCOLD I DNA. Functional expression was achieved without the addition of hemin or the co-expression of any chaperones. The presence or absence of the native signal sequence had a strong impact on the success of the expression, but the effect was not consistent for the different DyPs. While BaDyP and AajDyP were stable at 50 °C, the more thermolabile MsP2 and PoDyp, upon catalytic intervention, lend themselves to more rapid thermal inactivation. The bleaching of norbixin (E 160b) using MsP2 was most efficient at pH 4.0, while BaDyP and AajDypP worked best in the weakly acidic to neutral range, indicating a choice of DyPs for a broad field of applications in different food matrices. 相似文献
76.
Kateryna Bazaka 《Polymer Degradation and Stability》2010,95(6):1123-2961
Owing to the structural flexibility, uncomplicated processing and manufacturing capabilities, plasma polymers are the subject of active academic as well as industrial research. Polymer thin films prepared from non-synthetic monomers combine desirable optical and physical properties with biocompatibility and environmental sustainability. However, the ultimate expediency and implementation of such materials will dependent on the stability of these properties under varied environmental conditions. Polyterpenol thin films were manufactured at different deposition powers. Under ambient conditions, the bulk of ageing occurred within first 150 h after deposition and was attributed to oxidation and volumetric relaxation. Films observed for further 12 months showed no significant changes in thickness or refractive index. Thermal degradation behaviour indicated thermal stability increased for the films manufactured at higher RF powers. Annealing the films to 405 °C resulted in full degradation, with retention between 0.29 and 0.99%, indicating films' potential as sacrificial material. 相似文献
77.
Hoon T. Chung Christina M. Johnston Kateryna Artyushkova Magali Ferrandon Deborah J. Myers Piotr Zelenay 《Electrochemistry communications》2010,12(12):1792-1795
Cyanamide was used in the preparation series of metal–nitrogen–carbon (M–N–C) oxygen reduction catalysts. The best catalyst, treated at 1050 °C, shows good performance versus previously reported non-precious metal catalysts with an OCV ~ 1.0 V and a current density of 105 mA/cm2 (iR-corrected) at 0.80 V in H2/O2 fuel cell testing (catalyst loading: 4 mg cm? 2). Although nitrogen content has been previously correlated positively with ORR activity, no such trend is observed here for any nitrogen type. The combined effects of nitrogen and sulfur incorporation into the carbon may account for the high activity of the 1050 °C catalyst. 相似文献
78.
Viktor Yu. Kramarenko Tetyana A. Shantalil Iryna L. Karpova Kateryna S. Dragan Eleonora G. Privalko Valery P. Privalko Daniel Fragiadakis Polycarpos Pissis 《先进技术聚合物》2004,15(3):144-148
Polyimide (PI) nanocomposites prepared by the in situ generation of crosslinked organosilicon nanophase (ON) through the sol‐gel process were characterized by densities, thermally stimulated depolarization currents and dielectric relaxation spectroscopy. Both a looser molecular packing of PI chain fragments adjacent to the ON and a loose inner structure of the spatial aggregates of ON were assumed to be responsible for a non‐additive decrease of the experimental values of dielectric permittivity for the nanocomposites. The pattern of composition dependence of the apparent dielectric permittivity of the ON suggested a probability of a morphological change around the composition PAAS/MTS = 100/16 (presumably, a sort of percolation transition from small‐size, individual clusters into large‐size, infinite clusters). Thus, PI reinforced with the sol‐gel derived nanophase may have a reasonably good potential as low dielectric permittivity materials. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
79.
Andriy Kostruba Alexander Zaichenko Natalya Mitina Kateryna Rayevska Kateryna Hertsyk 《Central European Journal of Physics》2008,6(3):454-461
Functional oligoperoxide surfactants and coordinating oligoperoxide metal complexes were studied as modifiers of glass flat
plates to provide the localization of radical forming sites and other functional fragments in adsorbed polymeric layers of
a nanoscale thickness. Both the kinetics of the coating formation and properties of the nanolayers witness the dependence
of the packing density of oligoperoxide molecules in the coatings on the oligoperoxide natures, concentrations and conditions
of the sorption modification. The availability of definite amount of peroxide groups in formed nanolayer provides the possibility
of controlled radical graft polymerization initiated from modified surface leading to reliable surface protection, functionality
and targeted surface hydrophilic-hydrophobic properties.
相似文献
80.
Kumar Avishek Al-Jumaili Ahmed Prasad Karthika Bazaka Kateryna Mulvey Peter Warner Jeffrey Jacob Mohan V. 《Plasma Chemistry and Plasma Processing》2020,40(1):339-355
Plasma Chemistry and Plasma Processing - Antifouling/antibacterial coating derived from a sustainable natural resource for biomedical devices have shown promising outcomes, especially in the... 相似文献