The data acquisition is realized at a transmitted frequency of 4 MHz in harmonic mode. The experimental objective is to differentiate the tissue from the contrast agent and to delimit the tube boundary representing and modeling the blood vessel.
To study the impact of the Gaussian filter on the harmonic mode image, we investigate the modifications that happen on the distributions of the filtered image.
At x =1897203, the FFSA magnitude of the fundamental mode and each order harmonic mode of the isolated roughness are smaller than those of the smooth wall and distributed roughness wall, and the FFSA magnitude of each order harmonic disturbance for the distributed roughness is larger than that of the smooth wall except the fundamental mode.
For the downstream region of distributed roughness, the second-order harmonic mode is still the dominant mode in the range of x = 6.817512 to 7.798937 under different wall conditions, but the magnitude of the distributed roughness is significantly smaller than that of the other two types of wall conditions; even the third-order and fifth-order harmonic modes tend to disappear.
It should be mentioned that [f.sub.n] denotes the nth harmonic mode in this paper, namely, [f.sub.1] = 0.25, [f.sub.3] = 0.75, and [f.sub.n] = 0.25n and the following is the same.
It also can be seen that, due to the transformation of disturbance energy in the boundary layer, when s < 4.84436, the dominant mode in the boundary layer is transferred from the fundamental mode to the second harmonic mode during the process of changing from period phase into ablation phase; when s > 4.84436, the dominant mode in the boundary layer is transferred from the fundamental mode to near the third harmonic mode during the process of changing from period phase into ablation phase.
Grelu, "Multi-gigahertz repetition-rate-selectable passive harmonic mode locking of a fiber laser," Optics Express, vol.
Yang, "Passive harmonic mode locked all-normal-dispersion Yb-doped fibre lasers," Chinese Physics B, vol.
No spurious second harmonic mode can be found in the frequency band of 14 to 26 GHz in the results of both simulation and measurement.
When the second mode coupling occurs, the second harmonic mode will appear in the frequency band in which the power in the [TE.sub.10] mode has been suppressed.
She calls attention to later theories, such as those of Vallotti, who postulated "harmonic modes
" that resulted from the simplification of contrapuntal practice.
On the book's penultimate page Chenetier provides one more explanation for his interpretative hesitancy (let me praise his descriptive accuracies): "Perhaps the present pages are a witness to the fact that their author, `having developed a true fondness' for Paul Auster's harmonic modes
of suggestion, feels incapable of `delivering then with a straight,' academic, `face,' preferring to widen up the frame, open up the perspective and invite to the responsibilities of freedom, all of which attempts would be defeated by `final' words." Get busy reader and read Auster, this creator of imaginative spaces for odd things, and take Chenetier along as Baedeker.