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91.
Toshihiko Hoshi Ken-ichi Kumagai Keita Inoue Shigendo Enomoto Yoko Nobe Michio Kobayashi 《Journal of luminescence》2008,128(8):1353-1358
Tris(8-quinolinolato)aluminum(III) (Alq3) shows electronic absorption bands at 378, 360 (in a 1:1 mixed solvent of methanol and ethanol (ME) at 77 K), 334, 316, 300, 263, 255.8, and 233 nm in ethanol at room temperature. According to the polarized fluorescence excitation spectrum together with MO calculations, for instance, the 360 nm band is assigned to an LL CT transition (an intramolecular charge transfer transition between two ligands), and the 378 nm band to an LM/ML CT one (an intramolecular charge transfer transition between ligand and metal). Alq3 shows a broad fluorescence band peaking at around 478 nm in the ME matrix at 77 K. The emission spectrum measured with a phosphoroscope has two emission bands at 567 and 478 nm. The 567 nm band accompanies vibronic bands at 578 and 605 nm, being safely assigned to a phosphorescence of Alq3. The lifetimes of the 478 and 567 nm bands are both 5.4 ms. The lifetime of the 478 nm band together with the band position and its band shape indicate that this band can be assigned to a delayed fluorescence. 相似文献
92.
Satoshi Kadowaki Hiroshi Suzuki Hideaki Kobayashi 《Proceedings of the Combustion Institute》2005,30(1):169-176
The unstable behavior of cellular premixed flames induced by intrinsic instability is studied by two-dimensional unsteady calculations of reactive flows. In the present numerical simulation, the compressible Navier–Stokes equation including a one-step irreversible chemical reaction is employed. We consider two basic types of phenomena to account for the intrinsic instability of premixed flames, i.e., hydrodynamic and diffusive-thermal effects. The hydrodynamic effect is caused by the thermal expansion through the flame front; the diffusive-thermal effect is caused by the preferential diffusion of mass versus heat. A disturbance with several wavelength components is superimposed on a planar flame, and the formation of a cellular flame induced by hydrodynamic and diffusive-thermal effects is numerically simulated. After the cellular-flame formation, the combination and division of cells are observed. The behavior of cellular-flame fronts becomes more unstable when the Lewis number is lower than unity, since the diffusive-thermal effect has a great influence on the unstable behavior. The cell size changes with time, and its average is greater than the critical wavelength and becomes smaller by decreasing the Lewis number. The flame velocity of cellular flames depends strongly on the length of computational domain in the direction tangential to the flame front. As the length of computational domain increases, the flame velocity becomes larger. This is because the long-wavelength components of disturbances play an important role in the shape of cellular flames, i.e., in the flame-surface area. 相似文献
93.
Kiyoaki Kobayashi Takasuke Matsuo Hiroshi Suga Slimane Khairoun Alain Tressaud 《Solid State Communications》1985,53(8):719-722
Heat capacity of ammonium hexafluorovanadate (NH4)3 [VF6] has been measured with a miniaturized adiabatic calorimeter from 20 to 300 K. A phase transition was found at 280.44 ± 0.05 K with the associated entropy change Δtrs S = 24.9 ± 0.5 JK?1 mol?1. The entropy transition is accounted for by the orientational order-disorder changes of hexafluorovanadate ion and ammonium ion occupying respective octahedral sites, as in the cases of (NH4)3AlF6 and (NH4)3FeF6 crystals. Changes in infrared spectra relative to v3 vibrational mode of [VF6]3? ion can be explained by an orientational disorder of the anions in the high-temperature phase (HTP). The dependence of cubic root of the unit-cell volume of a family of ammonium cryolites on their transition temperatures is discussed in relation to the nature of interactions which induce the phase transition. 相似文献
94.
Kaori Kobayashi Takanori Matsui Shozo Tsunekawa 《Journal of Molecular Spectroscopy》2011,269(2):242-247
The trans-ethyl methyl ether molecule has three low-lying torsional modes, that is, two inequivalent methyl internal rotations and an asymmetric skeletal torsion. The internal rotations of the CCH3 and OCH3 methyl rotors and the skeletal torsion correspond to the vibrational modes, ν28, ν29 and ν30 respectively. In this study, the microwave absorption spectrum in the ν28 = 1 CCH3 torsional state was analyzed for the first time. Nine hundred fifty seven lines up to J = 48 and K = 4 were assigned, and the rotational, centrifugal distortion and internal rotational tunneling parameters were determined with the use of a tunneling matrix formalism. By combining the present results on the ν28 = 1 torsional state with those for the ν30 = 1 skeletal torsional state and the ν29 = 1 OCH3 torsional state, torsional couplings are estimated in order to understand quantitatively the inverted A/E sequence patterns observed for those three excited torsional states. 相似文献
95.
A simple semi-empirical model which takes account of effects of the anisotropy and the strong coupling interaction in the expression of the energy gap together with the ellipsoidal energy spectrum is proposed to explain results of specific heat measurements on layer structure compound 2H-NbSe2. The thermodynamic properties such as the electronic specific heat and the thermodynamic critical field deduced from this model give good agreements with experimental results. 相似文献
96.
Post's white-light moiré interferometry was used to obtain sequential records of the transientU
y
-displacement fields associated with stable crack growth in 7075-T6 and 2024-0, single-edge-notched (SEN) specimens with fatigued
cracks. TheU
y
-displacement fields are used to evaluate the crack-tip opening displacement (CTOD), far- and near-fieldJ-integral values, Dugdale-strip-yield model, William's polynomial function and the HRR field.
Paper was presented at 1985 SEM Spring Converence on Experimental Mechanics held in Las Vegas, NV on June 9–14. 相似文献
97.
The longitudinal relaxation time, T1, was measured in liquid 3He4He mixtures with molar concentrations of 3He of 0.12, 0.20 and 0.45 under saturated vapor pressure. λ-anomaly was clearly observed in the temperature dependence of T1. 相似文献
98.
Katsutoshi Kubota Makoto Minakata Shoichi Saito Shingo Uehara 《Optical and Quantum Electronics》1978,10(3):205-210
A low drive-voltage optical modulator using a Ti-diffused UNbO3 optical waveguide has been fabricated. Stabilization against ambient temperature change was realized by using a miniature halfwave plate. The halfwave voltage, 3 dB bandwidth, optical insertion loss and extinction ratio were 3·8 V (at 1·06m wavelength), 850 MHz, 10 dB and 13 dB, respectively. A reduction scheme for the optical absorption caused by metallic electrodes, and an analysis of the modulator high frequency response are also reported. 相似文献
99.
Upper bounds for survival probability of the contact process 总被引:3,自引:0,他引:3
100.
This paper studies the heavily trimmed sums (*)
[ns] + 1
[nt]
X
j
(n)
, where {X
j
(n)
}
j = 1
n
are the order statistics from independent random variables {X
1,...,X
n
} having a common distributionF. The main theorem gives the limiting process of (*) as a process oft. More smoothly trimmed sums like
j = 1
[nt]
J(j/n)X
j
(n)
are also discussed. 相似文献