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111.
112.
Mária Horváth Cagatay Ipbüker Miklós Hegedűs Tibor Kovács Alan H. Tkaczyk 《Journal of Radioanalytical and Nuclear Chemistry》2017,313(2):391-400
Our previous studies indicated the suitability of tobacco plants for biomonitoring remediated depositories, due to their 210Po and 210Pb accumulation ability. The methods and requirements of testing 210Pb uptake by leaf-surface adsorption was investigated and implemented in the construction of a controlled environment. Uranium ore (theoretical Rn concentration 638 Bqm?3) was the main source of radon and progeny. Rn concentrations were measured by RAD7, AlphaGUARD, EQF 3220, RTM 2100 and CR-39 SSNTDs (411–516 Bqm?3). Activity concentrations of the attached and unattached fractions were determined by EQF 3220. The results are indicative of good measurement setup for tracking 210Po(Pb) uptake pathways. 相似文献
113.
István Molnár Nándor Takács Krisztina Kurin‐Csörgei Miklós Orbán István Szalai 《国际化学动力学杂志》2013,45(7):462-468
The autocatalytic oxidation of a weak acid is a common building block of the pH oscillators. These reactions can be described by a simple general scheme that includes a protonation equilibrium and the oxidation of the protonated form of the weak acid. Here we show that independently from the chemical nature of the oxidizing agent, these reactions bear some general features, namely (1) the change in pH (ΔpH) observed during the reaction is determined by the acidity constant (KHA) and by the initial concentration of the unprotonated form of the weak acid (A?): , (2) the inflection time of the autocatalytic reaction (ti) depends reciprocally on KHA and on the initial hydrogen ion concentration, and (3) in the presence of a competitive reversible proton‐binding component (D?), that is not involved in the oxidation process, ΔpH follows a titration‐like curve as the concentration of D? is increased, ti is only slightly affected but the maximum rate of the autocatalytic process is significantly reduced. The slowing of the overall reaction is proportional to the acidity constant of the proton‐binding component. 相似文献
114.
Ildikó Mohammed-Ziegler Áron Szöllősy Miklós Kubinyi András Grofcsik Alajos Grün István Bitter 《Supramolecular chemistry》2013,25(6):415-421
Complexation of lithium ions by three chromoionophoric calix[4]arenes has been studied by 1H and 7Li NMR spectroscopy. The signalling unit of the chromoionophores is the N-methylpyridinium(methyleneimino) group in conjugation with a phenolic group of the calixarene ring while the coordination spheres contain esteric (ethoxycarbonylmethoxy) or etheric (ethoxy, propoxy) units. 1H NMR and NOESY measurements suggest the dominance of cone conformations of the calixarene rings with slight, solvent-dependent distortions. Complexation occurs only in the presence of a weak base. The interaction with lithium ions causes a broadening of both the 1H and 7Li NMR signals. Analysis of the chemical shifts in the three complexes indicates a different coordination environment for the lithium with the calixarene containing esteric groups from those having etheric groups. This explains the differences in the stabilities of the lithium complexes of the two types of calixarenes. 相似文献
115.
Miklös Ferenczi 《Mathematical Logic Quarterly》2011,57(1):87-94
We show that the representability of cylindric algebras by relativized set algebras depends on the scope of the operation transposition which can be defined on the algebra. The existence of “partial transposition” assures this kind of representability of the cylindric algebra (while the existence of transposition assures polyadic representation). Further we characterize those cylindric algebras in which the operator transposition can be introduced (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
116.
Mikl C Peters J Trapp M Kornmueller K Schneider WJ Prassl R 《Journal of the American Chemical Society》2011,133(34):13213-13215
Apolipoprotein B100 (apoB100)-containing plasma lipoproteins (LDL and VLDL) supply tissues and cells with cholesterol and fat. During lipolytic conversion from VLDL to LDL the size and chemical composition of the particles change, but the apoB100 molecule remains bound to the lipids and regulates the receptor mediated uptake. The molecular physical parameters which control lipoprotein remodeling and enable particle stabilization by apoB100 are largely unknown. Here, we have compared the molecular dynamics and elasticities of VLDL and LDL derived by elastic neutron scattering temperature scans. We have determined thermal motions, dynamical transitions, and molecular fluctuations, which reflect the temperature-dependent motional coupling between lipid and protein. Our results revealed that lipoprotein particles are extremely soft and flexible. We found substantial differences in the molecular resiliences of lipoproteins, especially at higher temperatures. These discrepancies not only can be explained in terms of lipid composition and mobility but also suggest that apoB100 displays different dynamics dependent on the lipoprotein it is bound to. Hence, we suppose that the inherent conformational flexibility of apoB100 permits particle stabilization upon lipid exchange, whereas the dynamic coupling between protein and lipids might be a key determinant for lipoprotein conversion and atherogenicity. 相似文献
117.
Le Ba Thong Mahian Omid Wongwises Somchai Szilágyi Imre Miklós 《Journal of Thermal Analysis and Calorimetry》2020,141(3):1173-1182
Journal of Thermal Analysis and Calorimetry - Thermal behavior and smoke characteristics of glass/epoxy laminate and its foam core sandwich composite were comprehensively investigated using... 相似文献
118.
Solvatochromic Study of Highly Fluorescent Alkylated Isocyanonaphthalenes,Their π‐Stacking,Hydrogen‐Bonding Complexation,and Quenching with Pyridine
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Dr. Miklós Nagy Dávid Rácz Dr. László Lázár Dr. Mihály Purgel Tamás Ditrói Dr. Miklós Zsuga Prof. Dr. Sándor Kéki 《Chemphyschem》2014,15(16):3614-3625
Mono‐ and dialkylated derivatives of 1‐amino‐5‐isocyanonaphthalene (ICAN) were studied as new members of a multifunctional, easy‐to‐prepare fluorophore family, which showed excellent solvatochromic properties. The monoallyl derivative and the starting ICAN exhibited strong fluorescence quenching in the presence of small amounts of pyridine. The formation of a hydrogen‐bonded ground‐state pyridine complex was detected; however, analysis of quantum chemical calculations suggested the presence of an additional π‐stacked pyridine complex. The Stern–Volmer plot of the quenching process exhibited a downward curvature and after reaching a minimum the fluorescence intensity increased back to a significant level at high pyridine concentrations. Significant fluorescence was observed even in pure pyridine. A new mechanism and a simple mathematical equation were derived to explain the downward curvature and the remaining fluorescence by the formation of a fluorescent π‐stacked complex. 相似文献
119.
M. Gomes da Silva A. Miklós A. Falkenroth P. Hess 《Applied physics. B, Lasers and optics》2006,82(2):329-336
Photoacoustic spectroscopy, in combination with a pulsed grazing-incidence optical parametric oscillator (GIOPO), was used
for sensitive detection of nitrous oxide (N2O) in ambient air. The ν1+ν3 combination band of N2O was excited with the idler beam of the GIOPO in the 2.76 μm–2.91 μm spectral region, where CO2 and water-absorption lines are also present. Three chemical filters filled with KOH, CaCl2, and P2O5 were used to reduce the CO2 and water concentrations to the level of several parts per billion (109) by volume (ppbv). Photoacoustic spectra containing several absorption lines were recorded and the concentration was determined
by an integral evaluation method and a fast Fourier transform evaluation method. The photoacoustic signal was calibrated by
a standard mixture of 50.6 parts per million by volume (ppmv) of N2O in synthetic air. Values of 311±5 ppbv, 314±5 ppbv, and 316±5 ppbv were found for three ambient samples collected at nearby
roads.
PACS 42.62.Fi; 42.65.Yj; 07.07.Df; 42.68.Ca 相似文献
120.
S. Schäfer M. Mashni J. Sneider A. Miklós P. Hess H. Pitz K.-U. Pleban V. Ebert 《Applied physics. B, Lasers and optics》1998,66(4):511-516
Received: 18 September 1997/Revised version: 11 November 1997 相似文献