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111.
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Miloš Zlámal 《Annali di Matematica Pura ed Applicata》1962,57(1):143-150
Summary We consider the Dirichlet problem for the equation Lε(u) ≡ uxx+ɛuyy++A(x, y)ux−B(y)uy+C(x, y)u=F(x, y) where B(y)>0 and ɛ is a small positive parameter. An asymptotic formula is proved, from which it follows
that in a suitable part of the domain of definition u(x, y, ɛ)→U(x, y) as ɛ→0+, where U(x, y) is the solution of the corresponding
boundary - value problem for the reduced equation L0(U)≡Uxx+A(x, y)Ux−B(y)U+C(x, y)U=F(x, y).
To Enrico Bompiani on his scientific Jubilee. 相似文献
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Gregorio Meira Miloš Netopilík Martin Potschka Irene Schnöll-Bitai Jorge Vega 《Macromolecular Symposia》2007,258(1):186-197
Summary: This article reviews some recent developments on the determination of the Band Broadening Function (BBF) in Size Exclusion Chromatography (SEC) of polymers. It was carried out in the frame of the IUPAC Project: “Data Treatment in Size Exclusion Chromatography of Polymers”. The correction for band broadening (BB) is important for quantitative determinations of the molar mass distribution (MMD) of narrow-distributed (or highly multimodal) polymers, and of derived variables such as kinetic parameters. In the narrow range of a molar mass standard, the BBF is uniform and of positive skewness. In a broad chromatographic range, the BBF is non-uniform and skewed; and it can be adequately represented by an exponentially-modified Gaussian function (EMG) of 2 parameters that vary slightly with elution volume: an increasing Gaussian variance and a decreasing exponential decay. Additionally, the total BBF variance remains almost constant if not close to the total exclusion limit. The following methods for determining BBF parameters are reviewed: a) a direct method based on assuming Poisson-distributed MMDs; b) a direct method based on measuring the mass- and molar mass chromatograms of narrow standards; c) a theoretical method based on a stochastic model that is equivalent to the Giddings-Eyring model; and d) a theoretical method based on a deterministic model obtained through an extension of the classical van Deemter expression. Ideally, the correction for BB requires a robust numerical inversion algorithm. However, alternative simplified solutions are also possible. 相似文献
117.
This paper examines and compares the effects of exposing commercial, off the shelf erasable programmable read-only memory (EPROM) and electrically erasable programmable read-only memory (E2PROM) components to gamma rays. Results obtained for CMOS-based EPROM (NM27C010) and E2PROM (NM93CS46) components provide evidence that EPROMs have a greater radiation hardness than E2PROMs. Moreover, the changes in EPROMs are reversible, and after erasure and reprogramming all EPROM components restore their functionality. On the other hand, changes in E2PROMs are irreversible. The obtained results are analyzed and interpreted on the basis of gamma ray interaction with the CMOS structure. 相似文献
118.
Ternary Hybrid γ‐Fe2O3/CrVI/Amine Oxidase Nanostructure for Electrochemical Sensing: Application for Polyamine Detection in Tumor Tissue 下载免费PDF全文
Dr. Emanuela Bonaiuto Dr. Massimiliano Magro Dr. Davide Baratella Dr. Petr Jakubec Elisabetta Sconcerle Dr. Milo Terzo Dr. Giovanni Miotto Dr. Alberto Macone Prof. Enzo Agostinelli Dr. Silvano Fasolato Dr. Rina Venerando Prof. Gabriella Salviulo Dr. Ondrej Malina Prof. Radek Zboril Prof. Dr. Fabio Vianello 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(20):6846-6852
Dichromate binds to surface‐active maghemite nanoparticles (SAMNs) to form a stable core–shell nanostructures (SAMN@CrVI). The hybrid was characterized by Mössbauer spectroscopy, high‐angle annular dark‐field imaging, electron energy‐loss spectroscopy, and electrochemical techniques, which revealed a strong interaction of dichromate with the nanoparticle surface. Electrochemical characterization showed lower charge‐transfer resistance, better electrochemical performance, and more reversible electrochemical behavior with respect to naked SAMNs. Moreover, SAMN@CrVI is an excellent electrocatalyst for hydrogen peroxide reduction. Furthermore, an enzyme, namely, bovine serum amine oxidase (BSAO: EC 1.4.3.6), was immobilized on SAMN@CrVI by self‐assembly to give a ternary hybrid nanostructured catalyst for polyamine oxidation (SAMN@CrVI‐BSAO). SAMN@CrVI‐BSAO was applied for the development of a reagentless, fast, inexpensive, and interference‐free polyamine biosensor, which was successfully exploited for the discrimination of tumorous tissue from healthy tissue in human crude liver extracts. 相似文献
119.
E. Hasović A. Gazibegović-Busuladžić M. Busuladžić D. B. Milošević W. Becker 《Laser Physics》2012,22(12):1819-1826
We investigate high-order above-threshold ionization (HATI) of homonuclear diatomic molecules by a few-cycle laser pulse. In order to describe molecular HATI in ultrashort laser pulses we have modified our molecular improved strong-field approximation (MISFA), which was developed for long laser pulses and in which the rescattering of the ionized electron off the parent ion was described using the first-order Born approximation (1BA). Now, we introduce the so-called molecular low-frequency approximation (MLFA) in which the elastic rescattering amplitude is calculated exactly. The angle-resolved electron energy spectra for HATI of N2 and O2 obtained using the MLFA are compared with those obtained within the MISFA. The difference between these spectra becomes significant for larger (re)scattering angles. This is due to the fact that the exact scattering amplitude, used in the MLFA, has minima for some values of the rescattering angles that are absent in the 1BA. Also, the rescattering plateau is lower for the MLFA spectra. We investigate the influence of the carrier-envelope phase on the high-energy part of the molecular HATI spectra. As in the atomic case, the left-right (backward-forward) asymmetry is also observed in the molecular case. 相似文献
120.
LC‐MS/MS method for the determination of haemanthamine in rat plasma,bile and urine and its application to a pilot pharmacokinetic study 下载免费PDF全文
Miloš Hroch Stanislav Mičuda Radim Havelek Jolana Cermanová Lucie Cahlíková Anna Hošťálková Daniela Hulcová Martina Řezáčová 《Biomedical chromatography : BMC》2016,30(7):1083-1091
Evidence gathered in various studies points to the fact that haemanthamine, an isoquinoline alkaloid, has multiple medicinally interesting characteristics, including antitumor, antileukemic, antioxidant, antiviral, anticonvulsant and antimalarial activity. This work presents, for the first time, a universal LC‐MS/MS method for analysis of haemanthamine in plasma, bile and urine which has been verified in a pilot pharmacokinetic experiment on rats. Chromatographic separation was performed on a pentafluorophenyl core–shell column in gradient elution mode with a mobile phase consisting of acetonitrile–methanol–ammonium formate buffer. A sample preparation based on liquid–liquid extraction with methyl tert‐butyl ether was employed with ambelline used as an internal standard. Quantification was performed using LC‐MS‐ESI(+) in Selected Reaction Monitoring mode. The method was validated according to the European Medicines Agency guideline in a concentration range of 0.1–10 μmol/L in plasma, bile and urine. The concentration–time profiles of haemanthamine in plasma, bile and urine after a single i.v. bolus of 10 mg/kg have been described for the first time. The presented study addresses the lack of information on haemanthamine pharmacokinetics and also introduces a new universal method of haemanthamine analysis in complex biological matrices. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献