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931.
Li-Ming Cao Yoshinori Matsuo Takuya Tsukioka Chul-Moon Yoo 《Physics letters. [Part B]》2009,679(4):390-395
We apply the Kerr/CFT correspondence to the rotating black p-brane solutions. These solutions give the simplest examples from string theory point of view. Their near horizon geometries have structures of AdS, even though black p-brane solutions do not have AdS-like structures in the non-rotating case. The microscopic entropy which can be calculated via the Cardy formula exactly agrees with Bekenstein–Hawking entropy. 相似文献
932.
933.
T. Kobayashi T. Kato Y. Matsuo M. Kurata-Nishimura Y. Hayashizaki J. Kawai 《Applied Physics A: Materials Science & Processing》2008,92(4):817-819
We investigate the so-called “matrix effect” on the relative intensities of ions in mixed solutions of alkali salts by using
femtosecond laser ablation time-of-flight mass spectrometry (fsLA-TOFMS). For the 1:1 mixed solution of sodium and potassium
salts, the intensity ratio of cations (Na+/K+) decreases as the total concentration increases. From the measurement for the mixed solution of lithium, sodium, potassium,
rubidium, and cesium solutions, we find out significant dependence of each ion intensity on the total concentration. The results
suggest that the electron transfer from neutral atoms to cations coexistent in the ablation plasma affects the relative ion
intensities observed with TOFMS when the total ion concentration is high. 相似文献
934.
Cross-sectional TEM analysis of laser-induced ripple structures on the 4H–SiC single-crystal surface
T. Okada H. Kawahara Y. Ishida R. Kumai T. Tomita S. Matsuo S. Hashimoto M. Kawamoto Y. Makita M. Yamaguchi 《Applied Physics A: Materials Science & Processing》2008,92(3):665-668
The microstructures of femtosecond laser-induced ripples formed on a 4H–SiC single-crystal surface were studied by cross-sectional
transmission electron microscopy (TEM), with particular attention on the crystal structure underlying fine and coarse ripples
differing in period and morphology. Conventional and high-resolution TEM analyses showed that a continuous amorphous layer
approximately 10 to 50 nm thick covers the topmost region of both fine and coarse ripples. These results strongly suggest
that the fundamental surface deformation process is common for the entire region of fine and coarse ripples, even though the
factors that determine their periods are different. 相似文献
935.
Comparison of plume expansion in femtosecond laser ablation on oxidized and non-oxidized Sm surfaces
M. Kurata-Nishimura Y. Matsuo T. Kobayashi T. Kato Y. Hayashizaki J. Kawai 《Applied Physics A: Materials Science & Processing》2008,92(4):1047-1050
Time development of Sm+ and Sm ablation plume produced by the femtosecond laser irradiation has been investigated. The two-dimensional spatial profiles
of Sm and Sm+ emitted from oxidized and non-oxidized Sm surface were visualized using a planar laser-induced fluorescence method. It was
observed that the flow velocity of Sm+ is much faster than that of Sm plume in both surfaces. The plumes from the oxidized Sm surface show higher velocity than
that from non-oxidized surface, which is originated by the small electric conductivity at the surface. Expansion property
observed for Sm+ and Sm plume in the oxidized Sm surface ablation implies the formation of the Knundsen layer nearby the surface. Meanwhile,
continuous emission of Sm indicates the large contribution of heating effect to emission process at the non-oxidized surface.
We conclude that the fsLA process strongly depends on the electric property of the ablated surface and the heating effect
contributes to the particle emission process on the conductive material surface. 相似文献
936.
Katsumi Sugita Yoshiwo Okamoto Matsuo Sekine 《International Journal of Theoretical Physics》2008,47(11):2875-2881
In a previous paper, we proposed the infinite sub-layer quark model, in which the proton and the neutron are made up of an
infinite number of point-like (structure-less) quarks u
∞ and anti-quarks u
∞
CP
at an infinite sub-layer level. In this paper, we propose that the dark matter is also made of an infinite number of quarks
u
∞ and anti-quarks u
∞
CP
. A pair of the ultimate quarks u
∞ and anti-quarks u
∞
CP
would be produced in the first moments after the Big Bang and then remain as the dark matter for all time, stable against
decay and subject only to the weak interaction and gravity. It is then shown that CP is violated in the doublet of u
∞ and u
∞
CP
quarks to account for the asymmetry of the number of particles and anti-particles in the present universe. Furthermore, it
is shown that the Higgs bosons are composed of u
∞ and u
∞
CP
dark matter particles and give the masses to gauge bosons, quarks and leptons. 相似文献
937.
We performed molecular dynamics (MD) simulations to study the characteristic sputtering process with large cluster ion impact. The statistical properties of incident Ar and sputtered Si atoms were examined using 100 different MD simulations with Ar1000 cluster impacting on a Si(0 0 1) target at a total acceleration energy of 50 keV. The results show that the kinetic energy distribution of Ar atoms after impact obeys the high-temperature Boltzmann distribution due to thermalization through high-density multiple collisions on the target. On the other hand, the kinetic energy distribution of sputtered target atoms demonstrates a hybrid model of thermalization and collision-cascade desorption processes. 相似文献
938.
Musashi M Oi T Eggenkamp HG Matsuo M 《Isotopes in environmental and health studies》2008,44(3):305-313
Stable chlorine isotope compositions (delta(37)Cl, per-mil: per thousand, vs. a standard sample of sea water) of Kusatsu-bandaiko hot water samples, taken regularly in the years between 1974 and 1995 in the Kusatsu-Shirane volcanic region, Japan, were measured mass-spectrometrically. The results show that the delta(37)Cl values of the waters taken before 1984 were at around-0.12 per thousand, whereas those after 1984 were at around+0.18 per thousand. The delta(37)Cl values are thus distinct across 1984, which is consistent with the classification by the Cl to S molar ratio (Cl/S): the higher the Cl/S ratio, the larger the delta(37)Cl value. The delta(37)Cl value increased as much as 0.30 per thousand during 5 years between 1980 and 1984. This isotopic enrichment is likely correlated with increasing Cl/S ratios, suggesting that the heavier isotope ((37)Cl) may have preferentially increased in the original Cl source of the hot spring across 1984 when volcanic activity likely increased at Mt Kusatsu-Shirane. 相似文献
939.
Critical condition of inner cylinder radius for sustaining rotating detonation waves in rotating detonation engine thruster 总被引:1,自引:0,他引:1
Akira Kawasaki Tomoya Inakawa Jiro Kasahara Keisuke Goto Ken Matsuoka Akiko Matsuo Ikkoh Funaki 《Proceedings of the Combustion Institute》2019,37(3):3461-3469
We describe the critical condition necessary for the inner cylinder radius of a rotating detonation engine (RDE) used for in-space rocket propulsion to sustain adequate thruster performance. Using gaseous C2H4 and O2 as the propellant, we measured thrust and impulse of the RDE experimentally, varying in the inner cylinder radius ri from 31 mm (typical annular configuration) to 0 (no-inner-cylinder configuration), while keeping the outer cylinder radius (ro = 39 mm) and propellant injector position (rinj = 35 mm) constant. In the experiments, we also performed high-speed imaging of self-luminescence in the combustion chamber and engine plume. In the case of relatively large inner cylinder radii (ri = 23 and 31 mm), rotating detonation waves in the combustion chamber attached to the inner cylinder surface, whereas for relatively small inner cylinder radii (ri = 0, 9, and 15 mm), rotating detonation waves were observed to detach from the inner cylinder surface. In these small inner radii cases, strong chemical luminescence was observed in the plume, probably due to the existence of soot. On the other hand, for cases where ri = 15, 23, and 31 mm, the specific impulses were greater than 80% of the ideal value at correct expansion. Meanwhile, for cases ri = 0 and 9 mm, the specific impulses were below 80% of the ideal expansion value. This was considered to be due to the imperfect detonation combustion (deflagration combustion) observed in small inner cylinder radius cases. Our results suggest that in our experimental conditions, ri = 15 mm was close to the critical condition for sustaining rotating detonation in a suitable state for efficient thrust generation. This condition in the inner cylinder radius corresponds to a condition in the reduced unburned layer height of 4.5–6.5. 相似文献
940.
Vinylic hydrogens at the beta-position of enones were effectively substituted with alkyl groups in a one-pot procedure to afford beta-alkyl enones in good to high isolated yields by conjugate addition of higher-order dialkyl cyanocuprates to enones, followed by a reaction with N-tert-butylbenzenesulfinimidoyl chloride at -78 degree C. 相似文献