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1.
A stochastic estimation technique has been applied to simultaneously acquired data of velocity and surface pressure as a tool
to identify the sources of wall-pressure fluctuations. The measurements have been done on a NACA0012 airfoil at a Reynolds
number of Re
c
= 2 × 105, based on the chord of the airfoil, where a separated laminar boundary layer was present. By performing simultaneous measurements
of the surface pressure fluctuations and of the velocity field in the boundary layer and wake of the airfoil, the wall-pressure
sources near the trailing edge (TE) have been studied. The mechanisms and flow structures associated with the generation of
the surface pressure have been investigated. The “quasi-instantaneous” velocity field resulting from the application of the
technique has led to a picture of the evolution in time of the convecting surface pressure generating flow structures and
revealed information about the sources of the wall-pressure fluctuations, their nature and variability. These sources are
closely related to those of the radiated noise from the TE of an airfoil and to the vibration issues encountered in ship hulls
for example. The NACA0012 airfoil had a 30 cm chord and aspect ratio of 1. 相似文献
2.
We present a simple model to rationalize the effects of environment on the reaction barrier frequencies derived from free energy profiles. These frequencies are relevant in deviations of a rate constant from its transition state theory value and in determining which environmental dynamics participate in the reaction. In particular, this simple model can be used to understand the changes in the reaction barrier frequencies of an enzymatic catalyzed reaction and the corresponding uncatalyzed process in aqueous solution, a change which has implications for dynamical environmental effects on the enzymatic reaction. Two possible cases are analyzed, in which the polarity (charge separation/localization) of the reacting system increases or decreases as the reaction advances. A simple modeling of the environment′s effects allows the explanation of an unusual “inverse” effect on the reaction frequencies, that is, a free energy barrier lowering accompanied by an increase of the reaction frequency, a behavior observed in some enzymes. The model predictions are successfully compared with results from full simulations for four different enzyme reactions. 相似文献
3.
Summary Roseocobaltic chloride was found to furnish characteristic crystalline reaction products with oxalates, sulfosalicylic acid, dithionates, ferriand ferrocyanides, silicofluorides and phosphomolybdates. Of these, only the first four reaction products are recommended for identification of the corresponding anions.
Zusammenfassung Aquo-pentammino-cobaltichlorid gibt mit Dithionat, Ferricyanid, Oxalat und Sulfosalicylat kristallisierte Reaktionsprodukte, die für den Nachweis dieser Ionen geeignet sind.
Résumé (L) L'aquo-pentammino-cobaltichlorure, forme des dithionates, ferri-cyanures, oxalates et sulfosalicylates cristallins qui conviennent pour la recherche de ces ions.相似文献
4.
Shyam K. Singh Oliver S. Fetzer John B. Hynes Thomas C. Williams 《Journal of heterocyclic chemistry》1991,28(5):1459-1461
Nitration of 2-amino-4-oxo-(3H)-5-trifluoromethylquinazoline is shown to occur exclusively at C6 as determined from an analysis of long range 1H and 19F scalar couplings to ring carbons. Nitration of 2-amino-4-oxo-(3H)-5-fluoroquinazoline is found to occur both at C6 and C8 as evident from an analysis of the 19F and 1H couplings of the ring protons. 相似文献
5.
Model trajectory calculations reveal a simple power law behavior for anharmonic oscillator energy transfer for all bound vibrational levels. 相似文献
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