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Scott C. Hagen D. Michael Parrish ? 《International Journal of Computational Fluid Dynamics》2013,27(7):585-595
This paper presents an a posteriori approach to unstructured mesh generation via a localized truncation error analysis and applies it to the Western North Atlantic Tidal (WNAT) model domain. The WNAT model domain encompasses the Gulf of Mexico, the Caribbean Sea, and the North Atlantic Ocean east to the 60°W Meridian. Herein, we pay particular attention to the area surrounding the Bahamas. A bathymetric data set with fine resolution is employed in seven separate linear, harmonic simulations of shallow water tidal flow for seven different tidal-forcing constituents. Each set of simulation results is used to perform a truncation error analysis of a linear, harmonic form of the depth-averaged momentum equations for each of the seven different tidal-forcing frequencies. Truncation error is then driven to a more uniform, domain-wide value by solving for local node spacing requirements. The process is built upon successful research aiming to produce unstructured grids for large-scale domains that can be used in the accurate and efficient modeling of shallow water flow. The methodology described herein can also be transferred to other modeling applications. 相似文献
54.
Alfin D. N. Vaz Wei Wei Wang Andrew J. Bessire Raman Sharma Anne E. Hagen 《Rapid communications in mass spectrometry : RCM》2010,24(14):2109-2121
A simple procedure is described to identify acyl‐glucuronides by coupled liquid chromatography/mass spectrometry after derivatization to a hydroxamic acid with hydroxylamine. The reaction specificity obviates the need for isolation of the acyl‐glucuronide from an extract. Glucuronides derived from carbamic acids, and alkyl‐ and aromatic amines, are inert to the derivatization reaction conditions, making the hydroxamic acid derivative a fingerprint for acyl‐glucuronides. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
55.
Pavel Exner Takashi Ichinose Hagen Neidhardt Valentin A. Zagrebnov 《Integral Equations and Operator Theory》2007,57(1):67-81
We introduce a new product formula which combines an orthogonal projection with a complex function of a non-negative operator.
Under certain assumptions on the complex function the strong convergence of the product formula is shown. Under more restrictive
assumptions even operator-norm convergence is verified. The mentioned formula can be used to describe Zeno dynamics in the
situation when the usual non-decay measurement is replaced by a particular generalized observables in the sense of Davies. 相似文献
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Oleg G. Voronin Daan J. van Haaster Elena E. Karyakina Wilfred R. Hagen Arkady A. Karyakin 《Electroanalysis》2007,19(21):2264-2266
The direct bioelectrocatalysis by an NAD(P)‐reducing hydrogenase is reported for the first time. In contrast to previous attempts to involve similar enzymes in bioelectrocatalysis [1–4], which were in fact unsuccessful, in our report an effective electrocatalysis by Pyrococcus furiosus hydrogenase is convincingly shown by (i) achievement of the hydrogen equilibrium potential and (ii) a high current of hydrogen oxidation (0.3 mA cm?2 at 100 mV overpotential and at 75 °C). The latter is just a few times lower compared to enzyme electrodes based on NAD(P)‐independent hydrogenases. 相似文献
59.
W. A. Knig S. Lutz M. Hagen R. Krebber G. Wenz K. Baldenius J. Ehlers H. Tom Dieck 《Journal of separation science》1989,12(1):35-39
O-Perpentylated β-cyclodextrin has been evaluated as chiral stationary phase in capillary gas chromatography. Enantioselectivity is observed towards many chiral hydroxy compounds, including cyanohydrins and carbohydrates. Most importantly, the enantiomers of many olefins and alkyl halides can be resolved on this chiral phase. The thermal stability of the cyclodextrin derivative exceeds 200°C. 相似文献
60.
Two Hexagonal Series of Lanthanoid(III) Oxide Fluoride Selenides: M6O2F8Se3 (M = La – Nd) and M2OF2Se (M = Nd,Sm, Gd – Ho)
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Dirk D. Zimmermann Hagen Grossholz Sarah Wolf Oliver Janka Alexander C. Müller Thomas Schleid 《无机化学与普通化学杂志》2015,641(11):1926-1933
Two hexagonal series of lanthanoid(III) oxide fluoride selenides with similar structure types can be obtained by the reaction of the components MF3, M2O3, M, and Se in sealed niobium tubes at 850 °C using CsI as fluxing agent. The compounds with the lighter and larger representatives (M = La – Nd) occur with the formula M6O2F8Se3, whereas with the heavier and smaller ones (M = Nd, Sm, Gd – Ho) their composition is M2OF2Se. For both systems single‐crystal determinations were used in all cases. The compounds crystallize in the hexagonal crystal system (space group: P63/m) with lattice parameters of a = 1394–1331 pm and c = 403–372 pm (Z = 2 for M6O2F8Se3 and Z = 6 for M2OF2Se). The (M1)3+ cations show different square antiprismatic coordination spheres with or without an extra capping fluoride anion. All (M2)3+ cations exhibit a ninefold coordination environment shaped as tricapped trigonal prism. In both structure types the Se2– anions are sixfold coordinated as trigonal prisms of M3+ cations, being first condensed by edges to generate trimeric units and then via faces to form strands running along [001]. The light anions reside either in threefold triangular or in fourfold tetrahedral cationic coordination. For charge compensation, both structures have to contain a certain amount of oxide besides fluoride anions. Since F– and O2– can not be distinguished by X‐ray diffraction, bond‐valence calculations were used to address the problem of their adjunction to the available crystallographic sites. 相似文献