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41.
The modal radiation impedance of a circumferential opening in a circular cylinder is obtained as a simple integral formula. Calculation results are presented, demonstrating the effects of the width/radius ratio of the opening. 相似文献
42.
A simple analysis has been carried out to examine acoustic effects of attaching to the termination of an annular duct a vaneless diffuser through which incident plane waves propagate and radiate out circumferentially. The results are shown in the form of a reflection coefficient which expresses the ration of the incident and reflected waves at the diffuser inlet. 相似文献
43.
Mathematische Zeitschrift - 相似文献
44.
Masumi Sato 《等离子体物理论文集》1969,9(5):371-381
Wave nature of stationary moving striations in helium and neon discharges in a uniform longitudinal magnetic field is studied. With the increase of the magnetic field, the frequency of natural striations decreases, while the wave length increases, and they damp out at high field region. Artificial excitations in these gases show that the wave length is proportional to the excitation frequency for given magnetic field and the slope of linear lines increases with the field. These wave nature of striations is explained following the dispersion relation derived from the consideration of waves of ionization and including effects of the magnetic field on the ionization. 相似文献
45.
Nagashima Y Hoshino K Ejiri A Shinohara K Takase Y Tsuzuki K Uehara K Kawashima H Ogawa H Ido T Kusama Y Miura Y 《Physical review letters》2005,95(9):095002
Two types of electrostatic modes with small-poloidal wave numbers (approximately 1 and 10-15 kHz) are observed in the edge region of Ohmically heated plasmas in the JFT-2M tokamak. The envelope of the higher frequency coherent mode is modulated at the frequency of the lower frequency mode. A bispectral analysis revealed that a significant nonlinear coupling among the two types of fluctuations and the broadband background turbulent potential fluctuations occurs inside the last closed magnetic flux surface, suggesting that a nonlinear process such as the parametric-modulational instability is involved. 相似文献
46.
Inner shell ionization cross sections by low-energy positron impact have been measured. Development of an x-ray detector with thin Si(Li) crystals has enabled the first measurements of the absolute cross sections for the positron impacts in the energy range below 30 keV. Threshold behavior of the measured cross sections for the Cu K shell and Ag L shell are compared with the theoretical results of Gryzinski and Kowalski [Phys. Lett. A 183, 196 (1993)]] and Khare and Wadehra [Can. J. Phys. 74, 376 (1996)]]. Good agreement has been found for the Cu K shell, while the experimental values for the Ag L shell were found to be smaller than the corresponding theoretical results. 相似文献
47.
Two recent experimental developments, when combined, may have far-reaching implications. S(phiK(S))<0, if confirmed, would imply large s-b mixing, a new CP phase, and right-handed dynamics. Large Deltam(B(s)) would be likely, making the B(s) program at hadron machines difficult. Reconstruction of B vertex from K(S) at B factories, as shown by BaBar's first measurement of SK(S)(pi(0)), makes SK(S)(pi(0)gamma) in B-->K(*0)gamma accessible. This would be a boon for B factory upgrades. Supersymmetric Abelian flavor symmetry, independently motivated, can realize all of this with a light sb(1) squark. B factory and collider studies of flavor, CP and supersymmetry, may not be what we had expected. 相似文献
48.
49.
A new aromadendrane-type sesquiterpenoid, 4(15)-aromadendren-12,5alpha-olide and an aromadendrane-guaianolide dimer have been isolated from the New Zealand liverwort Chiloscyphus subporosus. Their structures were established by extensive NMR techniques and X-ray crystallographic analysis. 相似文献
50.
H. Tang O. Guilbaud G. Jamelot D. Ros A. Klisnick D. Joyeux D. Phalippou M. Kado M. Nishikino M. Kishimoto K. Sukegawa M. Ishino K. Nagashima H. Daido 《Applied physics. B, Lasers and optics》2004,78(7-8):975-977
X-ray interference microscopy diagnostics of a nanosecond-pulse pumped Al (Z=13) plasma are presented. A transient picosecond Ni-like Ag X-ray laser (13.9 nm) is used as the probe beam and a wavefront division bi-mirror interferometer is adopted as the diagnosis tool. From the fringe shifts, the two-dimensional plasma density profile at 1 ns after the peak of the heating pulse is deduced. Opposite fringe shifts during the plasma development are observed and possible explanations for this behavior are discussed. This study will contribute to the validation of 1D and 2D hydrodynamic codes as well as to the better understanding of the physics during the development of laser produced plasmas. PACS 41.50.+h; 41.85.Ew; 42.55.Vc 相似文献