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11.
An Ethanol Biosensor Based on Simple Immobilization of Alcohol Dehydrogenase on Fe3O4@Au Nanoparticles 下载免费PDF全文
Anchalee Samphao Kanjana Kunpatee Sanchai Prayoonpokarach Jatuporn Wittayakun Ľubomír Švorc Dalibor M. Stankovic Kristina Zagar Miran Ceh Kurt Kalcher 《Electroanalysis》2015,27(12):2829-2837
An ethanol biosensor based on alcohol dehydrogenase (ADH) attached to Au seeds decorated on magnetic nanoparticles (Fe3O4@Au NPs) is presented. ADH was immobilized on Fe3O4@Au NPs, which were subsequently fixed by a magnet on a carbon paste electrode modified with 5 % (m : m) MnO2. Optimum conditions for the amperometric determination of ethanol with the biosensor were as follows: working potential +0.1 V (vs. Ag/AgCl); supporting electrolyte: 0.1 M phosphate buffer solution at pH 6.8 containing 0.25 mM of the coenzyme (NAD+); working electrode: carbon paste with magnetically attached Fe3O4@Au NPs (0.012 mg ? cm?2 electrode area) with immobilized alcohol dehydrogenase (120 units per cm2 of electrode area). Linearity between signal and concentration was found for the range from 0.1 to 2.0 M ethanol (r2=0.995) with a detection limit of 0.07 M, a sensitivity of 0.02 µA ? mM?1 ? cm?2, a reproducibility of 4.0 % RSD, and a repeatability of 2.7 % RSD. The results for the determination of ethanol in alcoholic beverages showed good agreement with gas chromatography (GC) with recovery of 96.0 – 108.8 %. 相似文献
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Tijana T. Ivancevic Bojan Jovanovic Ratko Stankovic Sasa Markovic 《Central European Journal of Physics》2010,8(6):873-882
In this paper we propose the time-dependent Hamiltonian form of human biomechanics, as a sequel to our previous work in time-dependent
Lagrangian biomechanics [1]. This is the time-dependent generalization of an ‘ordinary’ autonomous human biomechanics, in
which total mechanical + biochemical energy is not conserved. In our view, this time-dependent energetic approach is much more realistic than the autonomous one. Starting with the Covariant
Force Law, we first develop autonomous Hamiltonian biomechanics. Then we extend it using a powerful geometrical machinery
consisting of fibre bundles and jet manifolds associated to the biomechanical configuration manifold. We derive time-dependent,
dissipative, Hamiltonian equations and the fitness evolution equation for the general time-dependent human biomechanical system. 相似文献
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Douglas E. Murphy Peter S. Dragovich Benjamin K. Ayida Thomas M. Bertolini Lian-Sheng Li Frank Ruebsam Nebojsa S. Stankovic Zhongxiang Sun Jingjing Zhao Yuefen Zhou 《Tetrahedron letters》2008,49(5):811-815
A general procedure is described for the preparation of 6-substituted-5-hydroxy-3-oxo-2,3-dihydro-pyridazine-4-carboxylic acid ethyl esters (6-substituted-5-hydroxy-3(2H)-pyridazinone-4-carboxylic acid ethyl esters). These compounds are shown to undergo selective alkylation at the 2-position in moderate to good yields (19-77%) to afford 2,6-disubstituted-5-hydroxy-3-oxo-2,3-dihydro-pyridazine-4-carboxylic acid ethyl esters (2,6-disubstituted-5-hydroxy-3(2H)-pyridazinone-4-carboxylic acid ethyl esters). 相似文献
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Milena Zivkovic Nenad Zlatic Tijana Zeremski Milan Stankovic Vesna Manic Dragana Krstic Dragoslav Nikezic 《Journal of Radioanalytical and Nuclear Chemistry》2022,331(3):1285-1298
Journal of Radioanalytical and Nuclear Chemistry - Vertical distribution of natural radionuclides, 137Cs and heavy metals were measured in soil and plants collected from Kragujevac surroundings.... 相似文献
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Mixing in Circular and Non-circular Jets in Crossflow 总被引:1,自引:0,他引:1
Coherent structures and mixing in the flow field of a jet in crossflow have been studied using computational (large eddy simulation)
and experimental (particle image velocimetry and laser-induced fluorescence) techniques. The mean scalar fields and turbulence
statistics as determined by both are compared for circular, elliptic, and square nozzles. For the latter configurations, effects
of orientation are considered. The computations reveal that the distribution of a passive scalar in a cross-sectional plane
can be single- or double-peaked, depending on the nozzle shape and orientation. A proper orthogonal decomposition of the transverse
velocity indicates that coherent structures may be responsible for this phenomenon. Nozzles which have a single-peaked distribution
have stronger modes in transverse direction. The global mixing performance is superior for these nozzle types. This is the
case for the blunt square nozzle and for the elliptic nozzle with high aspect ratio. It is further demonstrated that the flow
field contains large regions in which a passive scalar is transported up the mean gradient (counter-gradient transport) which
implies failure of the gradient diffusion hypothesis. 相似文献
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One way medial efferents are thought to inhibit responses of auditory-nerve fibers (ANFs) is by reducing the gain of the cochlear amplifier thereby reducing motion of the basilar membrane. If this is the only mechanism of medial efferent inhibition, then medial efferents would not be expected to inhibit responses where the cochlear amplifier has little effect, i.e., at sound frequencies in the tails of tuning curves. Inhibition at tail frequencies was tested for by obtaining randomized rate-level functions from cat ANFs with high characteristic frequencies (CF > or = 5 kHz), stimulated with tones two or more octaves below CF. It was found that electrical stimulation of medial efferents can indeed inhibit ANF responses to tail-frequency tones. The amplitude of efferent inhibition depended on both sound level (largest near to threshold) and frequency (largest two to three octaves below CF). On average, inhibition of high-CF ANFs responding to 1 kHz tones was around 5 dB. Although an efferent reduction of basilar-membrane motion cannot be ruled out as the mechanism producing the inhibition of ANF responses to tail frequency tones, it seems more likely that efferents produce this effect by changing the micromechanics of the cochlear partition. 相似文献
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R. S. Stankovic 《分析论及其应用》1991,7(2):1-19
In this paper we discuss the definition of Gibbs derivatives on finite, not necessarily Abelian, groups in terms of the partial
Gibbs derivatives. We consider the matrix representation of Gibbs derivatives defined in this way, which enables us to disclose
FFT-like algorithms for the calculation of the values of Gibbs derivatives of functions on finite groups into fields admitting
the existence of a Fourier transform on groups. 相似文献