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21.
Vladislav?Tomi?i?Email author Vjekoslav?Butorac Jadranka?Viher Vladimir?Simeon 《Journal of solution chemistry》2005,34(6):613-616
The effect of temperature on the π∗←π transition band in the UV absorption spectrum of NO3−(aq) centered at ≈200 nm was studied in the temperature range 10–70 ∘C. The observed temperature independence of this band was in contrast to the significant influence of temperature on the nitrate π∗←n transition reported recently by us. However, taking into account the electronic states involved in both the transitions, it was concluded that this finding was in accordance with our previous assumption that interconversion between spectrally distinct (with respect to π∗←n band) nitrate species included the rupture/formation of hydrogen bond(s) in the hydration shell of the nitrate ion. 相似文献
22.
Shakirova JR Grachova EV Gurzhiy VV Koshevoy IO Melnikov AS Sizova OV Tunik SP Laguna A 《Dalton transactions (Cambridge, England : 2003)》2012,41(10):2941-2949
The reactions between trinuclear gold complex tppmAu(3)Cl(3) (tppm = tris(diphenylphosphino)methane), arylacetylenes HC(2)C(6)H(4)X and Cu(+) under basic conditions result in formation of the heterometallic complexes [tppm(AuC(2)C(6)H(4)X)(3)Cu](+), X = H (1), COOMe (2), CN (3), OMe (4), NH(2) (5). These compounds belong to one structural motif and consist of the heterometallic {(AuC(2)C(6)H(4)X)(3)Cu} core stabilized by the tridentate phosphine. Compounds 1-5 were characterized by polynuclear NMR and IR spectroscopy, ESI-MS and single-crystal X-ray analysis. Luminescence properties of these complexes have been studied and revealed a substantial red shift of the emission maxima with the increase in the electron donicity of the alkynyl ligands substituents in the 550-680 nm range. The theoretical calculations of the electronic structures showed that variations of the substituents on the alkynyl ligands display very little effect on the molecular structural parameters but show appreciable influence on the orbital energies and luminescence characteristics of the compounds under study. 相似文献
23.
V. P. Gorelov V. B. Balakireva I. Yu. Yaroslavtsev V. A. Kazantsev E. G. Vaganov 《Russian Journal of Electrochemistry》2007,43(8):888-893
Highly compact (99%) solid electrolyte Ce0.8Gd0.2O1.9 with submicron (0.3 μm) grains is synthesized. The dilatometric (20–850°C) and conductivity (180–350°C) measurements are performed on the electrolyte in air and as a function of the partial oxygen pressure \(p_{O_2 } \) (0.21?1×10?25 atm) at 600, 700, and 800°C. An inflection is found in the temperature dependences of the thermal coefficient of linear expansion and conductivity (impedance measurements) at ~230°C, which is the evidence for a phase transition. The activation energies for conduction in the grain bulk and boundaries differ only slightly, indicating that the grain boundaries’ resistance is caused not by the precipitation of the second phase at the boundaries, but most probably by the presence of intergranular nanopores. The dilatometric measurements confirm a significant increase in the linear dimensions of Ce0.8Gd0.2O1.9 in the reducing atmospheres with a parallel increase in its electron conductivity. The electron conductivity and specific elongation increase proportionally to \(p_{O_2 }^{ - 1/4} \) at all temperatures. The \(p_{O_2 } \) values, at which the transport numbers of ions t i = 0.5, are determined. They are 10?22.5, 10?20, and 10?18 atm at 600, 700, and 800°C, respectively. 相似文献
24.
Biofunctionalization of Multiwalled Carbon Nanotubes by Electropolymerized Poly(pyrrole‐concanavalin A) Films 下载免费PDF全文
Dr. Vladislav Papper Dr. Kamal Elouarzaki Dr. Karine Gorgy Ayrine Sukharaharja Dr. Serge Cosnier Prof. Robert S. Marks 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(42):13561-13564
The synthesis and electropolymerization of a pyrrolic concanavalin A derivative (pyrrole‐Con A) onto a multiwalled carbon nanotube (MWCNT) deposit is reported. Glucose oxidase was then immobilized onto the MWCNT‐poly(pyrrole‐Con A) coating by affinity carbohydrate interactions with the polymerized Con A protein. The resulting enzyme electrode was applied to the amperometric detection of glucose exhibiting a high sensitivity of 36 mA cm?2 mol?1 L and a maximum current density of 350 μA cm?2. 相似文献
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Novel types of hydrazinopeptide-like units containing five elements of diversity have been prepared in two steps using sequential
Ugi reactions. 相似文献
28.
Konrad Eichhorn Colombo Vladislav V. Kharton Alexandre P. Viskup Andrei V. Kovalevsky Aliaksandr L. Shaula Olav Bolland 《Journal of Solid State Electrochemistry》2011,15(2):329-347
A gas turbine power plant for CO2 capture, based on oxygen-permeable membranes with mixed ionic-electronic conductivity, was analysed with respect to long-term
stability by means of numerical simulation. Due to the attractive transport and physicochemical properties of mixed-conducting
La2NiO4+δ, this nickelate was selected as a prototype membrane material for this application. Experiments showed very slow degradation
of La2NiO4+δ membranes at oxygen chemical potentials close to atmospheric conditions, which are associated with kinetic demixing and other
microstructure-related factors. Interaction with CO2 in the intermediate temperature range also leads to lower oxygen permeation, whilst increasing oxygen pressure may cause
partial phase decomposition and microstructural changes, thus again limiting the range of possible operation conditions. The
relevant operational constraints were included in a detailed membrane-based gas turbine power plant model. The membrane performance
degradation with time was approximated by a linear function with average rate of 3.3% per 1,000 operation hours. Furthermore,
performance deterioration of the gas turbine compressor and turbine were also considered. Simulations revealed that the power
plant is substantially affected by degradation of the ceramic membranes and turbomachinery components. The already rather
small operating window was further narrowed when compared with a conventional gas turbine power plant. Two different designs
of the membrane-based power plant were analysed: (1) with and (2) without additional combustors (afterburners) between the
membrane reactor and the gas turbine. Afterburners increase thermal efficiency as well as power output, but also lead to non-negligible
CO2 emissions. In order to have a frame of comparison, results for a conventional gas turbine power plant with degradation of
turbomachinery components are also presented. Simulations representing changes in ambient temperature and fuel composition
as well as failure incidents were executed to analyse the susceptibility of the gas turbine power plant to external and internal
changes. 相似文献
29.
Maxim A. Mironov Iliya D. Shulepov Vladislav S. Ponomarev Vasily A. Bakulev 《Colloid and polymer science》2013,291(7):1683-1691
A novel method for obtaining cross-linked microgels of apple pectin has been introduced. This method is based on the Ugi four-component condensation in colloidal suspensions of pectinic acid and amines. Using various processing parameters (the polysaccharide concentration, the type and density of crosslink, and the optimal pH range), particles with controlled colloidal properties have been obtained. Lightly cross-linked polysaccharide chains acquire anionic character due to deprotonation of the carboxyl groups at pH?9–10. Increasing the degree of cross-linking leads to a polyampholyte microgel, which can be protonated in acidic medium or deprotonated in basic medium. Polyampholyte microgels derived from apple pectin have proved to be an effective Pickering emulsifier at low concentrations and pH?2–3, forming stable oil-in-water emulsions. These Pickering emulsions exhibited pH-responsive behavior: raising the solution pH to 10 resulted in immediate demulsification due to the destabilization of microgel network at the oil–water interface. 相似文献
30.
Selberg-type integrals that can be turned into constant term identities for Laurent polynomials arise naturally in conjunction with random matrix models in statistical mechanics. Built on a recent idea of Karasev and Petrov we develop a general interpolation based method that is powerful enough to establish many such identities in a simple manner. The main consequence is the proof of a conjecture of Forrester related to the Calogero–Sutherland model. In fact we prove a more general theorem, which includes Aomoto's constant term identity at the same time. We also demonstrate the relevance of the method in additive combinatorics. 相似文献