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Use is made of computer simulated turbulent signals to calculate the rms of the velocity cone angle. The calculation compares
favourably with X-probe data close to the axis of a circular jet. In this flow, the vector cone angle can exceed 90°, even
on the axis. As a consequence, the rms values of the cone angle and of the lateral velocity fluctuation can be seriously underestimated
with a 90° X-probe. Support for this is provided by measurements with a 120° X-probe. 相似文献
83.
Spectra and spectral coherences of mainly the lateral velocity fluctuations, measured in the wake of a circular cylinder, strongly suggest that the origin of the far-wake organised motion can be traced back to the cylinder. A possible mechanism for the development of the organised motion is suggested. 相似文献
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Hot-wire measurements of the spanwise vorticity fluctuation z have been carried out in a turbulent boundary layer subjected to concentrated suction, applied through a porous wall strip. The results indicate that, relative to the no-suction case, the rms value of z is significantly reduced in the near-wall region, with this reduction increasing with the suction rate . The reduction near the wall suggests an alteration in the dynamics of the layer. As the Reynolds number increases, the dynamics of the layer in the near-wall region become more intense and suction becomes less effective. 相似文献
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Validation and quality control of methylmercury determinations by means of capillary electrophoresis 总被引:1,自引:0,他引:1
Antonia Maria Carro Diaz R. A. Lorenzo-Ferreira R. Cela-Torrijos 《Mikrochimica acta》1996,123(1-4):73-86
Methyl-Hg is one of the most dangerous pollutants in the environment. It is highly toxic and accumulates through the food chain. Tuna fish especially tends to concentrate Hg in the form of methyl-Hg. Quality assurance is a well established routine in analytical laboratories to control the variability of analytical results and to maintain adequate stability, detection power and reproducibility. Capillary electrophoresis (CE) has shown in recent years powerful capabilities for the resolution and analysis of very complex samples. The high resolution and peak capacity characteristics of this technique could be used favourably in speciation studies of organo-Hg compounds. Since the time needed for separation is usually very short in this technique, it lends itself to routine analysis. The application of quality control approaches in the analysis of methyl-Hg in tuna freeze-dried materials using CE is reported. 相似文献
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Antonia Wachter-Zeh Valentin Afanassiev Vladimir Sidorenko 《Designs, Codes and Cryptography》2013,66(1-3):57-73
Gabidulin codes are the analogues of Reed–Solomon codes in rank metric and play an important role in various applications. In this contribution, a method for efficient decoding of Gabidulin codes up to their error correcting capability is shown. The new decoding algorithm for Gabidulin codes (defined over ${\mathbb{F}_{q^m}}$ ) directly provides the evaluation polynomial of the transmitted codeword. This approach can be seen as a Gao-like algorithm and uses an equivalent of the Euclidean Algorithm. In order to achieve low complexity, a fast symbolic product and a fast symbolic division are presented. The complexity of the whole decoding algorithm for Gabidulin codes is ${\mathcal{O} (m^3 \, \log \, m)}$ operations over the ground field ${\mathbb{F}_q}$ . 相似文献