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131.
Serre's nonnegativity conjecture for intersection multiplicities has recently been proven by O. Gabber. In this paper we investigate Serre's positivity conjecture using the methods which he developed. We show in particular that the positivity conjecture has implications for properties of symbolic powers of prime ideals in regular local rings. 相似文献
132.
133.
Simultaneous DPTV/PLIF measurements of a turbulent jet 总被引:5,自引:0,他引:5
Simultaneous measurements of instantaneous velocity and concentration fields were performed using digital particle tracking
velocimetry and planar laser- induced fluorescence for a turbulent jet at a Reynolds number of 3000. The measurements of mean
velocity, turbulent stresses, mean concentration, concentration variance, and turbulent flux of tracer all collapse onto self-similar
profiles in the far field of the jet. The measurements showed excellent agreement with previous point velocity and concentration
measurements. It is concluded that the system is an effective means of measuring the velocity and concentration distributions
and turbulent characteristics.
Received: 7 July 1999/Accepted: 9 February 2000 相似文献
134.
135.
F. Wirth V. Lenher C. C. Meloche E. J. Roberts F. J. Metzger Ph. E. Browning H. E. Palmer C. James und L. A. Pratt 《Fresenius' Journal of Analytical Chemistry》1919,58(8):358-361
Ohne Zusammenfassung 相似文献
136.
Chymotrypsin, covalently immobilized to the surface of an IrO2-coated titanium electrode, responds potentiometrically to various substrates. A flow-injection system is described for assay of the activity of the immobilized enzyme with N-benzoyl-l-tyrosine ethyl ester as substrate and an ultraviolet detector. Least-squares fits of peak height vs. time typically yield correlation coefficients of 0.999 and standard errors of estimate of 0.0043 absorbance for a total absorbance change of about 0.130. Slopes of such plots vary linearly with enzyme activity. 相似文献
137.
S. C. L. Gerritzen M. Kaufman L. Rosenthaler M. Roy S. Camilla J. Großfeld S. H. Bertram C. Stiebel G. W. Jennings R. D. Lewis J. Pritzker R. Jungkunz P. Bruère A. Fourmont W. L. Roberts H. A. Schuette J. K. Chowdhury S. M. Das-Gupta A. L. Bernoullie 《Analytical and bioanalytical chemistry》1933,92(11-12):451-461
138.
The influence of extraneous sounds on the perceptual estimation of first-formant frequency in vowels 总被引:1,自引:0,他引:1
The contribution of extraneous sounds to the perceptual estimation of the first-formant (F1) frequency of voiced vowels was investigated using a continuum of vowels perceived as changing from/I/to/epsilon/as F1 was increased. Any phonetic effects of adding extraneous sounds were measured as a change in the position of the phoneme boundary on the continuum. Experiments 1-5 demonstrated that a pair of extraneous tones, mistuned from harmonic values of the fundamental frequency of the vowel, could influence perceived vowel quality when added in the F1 region. Perceived F1 frequency was lowered when the tones were added on the lower skirt of F1, and raised when they were added on the upper skirt. Experiments 6 and 7 demonstrated that adding a narrow-band noise in the F1 region could produce a similar pattern of boundary shifts, despite the differences in temporal properties and timbre between a noise band and a voiced vowel. The data are interpreted using the concept of the harmonic sieve [Duifhuis et al., J. Acoust. Soc. Am. 71, 1568-1580 (1982)]. The results imply a partial failure of the harmonic sieve to exclude extraneous sounds from the perceptual estimation of F1 frequency. Implications for the nature of the hypothetical harmonic sieve are discussed. 相似文献
139.
140.
Irvine Masson P. V. Dupré Orme Masson R. W. Roberts und A. Fraser 《Fresenius' Journal of Analytical Chemistry》1911,50(12):765-767
Ohne Zusammenfassung 相似文献