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Kiyoshi Sogo
1993 年 62 巻 7 号 p.
2187-2191
発行日: 1993/07/15
公開日: 2007/06/01
ジャーナル
認証あり
The eigenvalue problem is solved exactly for the excited states of the Calogero-Sutherland-Moser model. The Young diagrams play an essential role in deriving solutions. Each eigenfunction, which is an irreducible representation of the λ-deformed symmetry group, is characterized by the corresponding Young diagram.
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Shozo Takeno, Kazuko Kawasaki, Kazuko Taniguchi
1993 年 62 巻 7 号 p.
2192-2195
発行日: 1993/07/15
公開日: 2007/06/01
ジャーナル
認証あり
Analytical solutions to nonlinear difference equations describing stationary states of the
d-dimensional classical O(2) (XY) spin model are studied. The Hirota bilinear operator formalism is employed to obtain exact and approximate stationary vortexlike-mode solutions having a form somewhat similar to a discrete version of vortex solutions to the two-dimensional sine-Gordon equation. The former exists for a specific case, while the existence condition for the latter is much less restrictive. The obtained analytical result is demonstrated in numerical calculations of vortex profiles for a two-dimensional model O(2) spin system, in which a single vortex and a periodic array of vortex-antivortex pairs are shown.
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Kousuke Yakubo, Takamichi Terao, Tsuneyoshi Nakayama
1993 年 62 巻 7 号 p.
2196-2199
発行日: 1993/07/15
公開日: 2007/06/01
ジャーナル
認証あり
It is found, through simulation of the density of states on a large scale, that the spectral dimensions \ ilde
dAF of percolating Heisenberg antiferromagnets take a value very close to
unity independent of Euclidean dimension
d. This finding is interpreted in terms of a dynamic scaling argument.
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Sadao Isogami, Mitsugu Matsushita
1993 年 62 巻 7 号 p.
2200-2203
発行日: 1993/07/15
公開日: 2007/06/01
ジャーナル
認証あり
Structural and statistical properties of directed percolation in two dimensions are studied numerically. The self-affinity of individual clusters is confirmed and their scaling exponents are obtained. An exponent characterizing the cluster-size distribution is also obtained. We confirm a scaling law to be valid for these exponents.
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Iwao Hosokawa
1993 年 62 巻 7 号 p.
2204-2207
発行日: 1993/07/15
公開日: 2007/06/01
ジャーナル
認証あり
The 3-dimensional domain with strong energy dissipation (above a certain threshold) in isotropic turbulence is displayed using a 3D generalized binomial Cantor set model, which is in itself a multifractal. This artificially made display simulates the corresponding domain of a realization of isotropic turbulence by direct numerical simulation so well that we may be convinced that all dissipative regions in real turbulence form the multifractal designated by this model, and that the domain surface has a fractal dimension corresponding to the threshold value.
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Yoshifumi Saitou, Yoshiharu Nakamura, Yoshinobu Kawai
1993 年 62 巻 7 号 p.
2208-2211
発行日: 1993/07/15
公開日: 2007/06/01
ジャーナル
認証あり
An ion beam which is inclined about 70 degrees from the direction of wave propagation is injected into plasmas to excite the ion-ion instability. When the ion beam is modulated by an external RF field, the instability is suppressed and the growth or damping rate changes from that without modulation. In particular, it is found from these results that when the modulation frequency is near the ion plasma frequency
fpi, the growth or damping rate changes markedly. Furthermore, it is observed that a peak in the energy distribution function of the ion beam splits into two peaks when the modulation frequency is near
fpi.
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Hitoshi Hojo, Tadatsugu Hatori
1993 年 62 巻 7 号 p.
2212-2215
発行日: 1993/07/15
公開日: 2007/06/01
ジャーナル
認証あり
Bounce resonance heating and associated radial transport in a magnetic mirror are studied. A general expression for the absorbed power and radial particle flux due to bounce resonance is obtained by use of a gyrokinetic equation with the eikonal representation for waves. It is shown that the power absorption yields the outward (inward) particle flux with positive (negative) azimuthal mode number of RF wave fields, and that the power emission, i.e., instabilities, yields the reverse particle flux with the same mode number for the ion. The particle flux for the electron is opposite that for the ion.
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Masashige Onoda, Tamotsu Inabe
1993 年 62 巻 7 号 p.
2216-2219
発行日: 1993/07/15
公開日: 2007/05/29
ジャーナル
認証あり
The role of structural change in the first-order magnetic-nonmagnetic phase transition in the triangular lattice compound LiVO
2 has been studied by means of X-ray four-circle and differential scanning calorimetric analyses. A set of reflections of the (1/3 1/3 0) vector have been observed accompanied by diffuse streaks along the
c*-axis in nearly stoichiometric crystals at room temperature. The analyses of average structure suggest a displacement of V ions of about 0.1 Å from the ideal sites within the basal plane. On the basis of the difference between the change in internal energies and that in magnetic energies above and below the transition temperature
Tc1,2, the lattice below
Tc1,2 has been found to be more unstable than that above
Tc1,2.
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Akiko Harasaki, Arata Tanaka, Takeo Jo
1993 年 62 巻 7 号 p.
2220-2223
発行日: 1993/07/15
公開日: 2007/06/01
ジャーナル
認証あり
We theoretically discuss the capability of resonant photoemission with soft X-rays in clarifying the valence electronic state, by choosing Ce 4
d core X-ray photoemission spectroscopy (4
d XPS) at the Ce 3
d threshold in CeRh
3B
2 with hexagonal crystal structure. On the basis of the Anderson model including multiplet splitting, we show that the dependence of 4
d XPS on the energy and the linear polarization with respect to the hexagonal
c-axis of the incident photon and the binding energy can be a powerful characteristic for probing a proposed uniaxial anisotropic distribution of 4
f electrons.
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Hiroshi Sawa, Masafumi Tamura, Shuji Aonuma, Reizo Kato, Minoru Kinosh ...
1993 年 62 巻 7 号 p.
2224-2228
発行日: 1993/07/15
公開日: 2007/05/29
ジャーナル
認証あり
Magnetic and structural studies of giant metal (M)-insulator (I)-metal reentrant transitions in the partially deuterated molecular conductors (DMe-DCNQI-
dn)
2Cu (
n=2, 3) are presented. In the insulating phase, Curie-Weiss-like susceptibilities with reduced Curie constants and diffusive satellite reflections showing a threefold superstructure were observed. The results are discussed in terms of novel electronic states associated with the 3D narrow ‘
d-band’ in the 1D 2
pπ conduction band.
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Ren-ichi Yamada, Shingo Katsumoto, Fumio Komori, Shun-ichi Kobayashi
1993 年 62 巻 7 号 p.
2229-2232
発行日: 1993/07/15
公開日: 2007/05/29
ジャーナル
認証あり
We measured the temperature dependence of the electrical conduction of granular films of Cu with a mean grain size of 40 Å, for which sheet conductances are much less than the quantum value 4
e2⁄
h. The results are interpreted in terms of the charge Kosterlitz-Thouless-Berezinskii transition mechanism.
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Masakiyo Horioka, Yuiti Satuma, Hirokazu Yanagihara
1993 年 62 巻 7 号 p.
2233-2236
発行日: 1993/07/15
公開日: 2007/05/29
ジャーナル
認証あり
The complex dielectric constant of Rochelle salt crystal has been measured at frequencies from 1.0 GHz to 35.8 GHz in a temperature region from 90 K to 310 K. Dielectric dispersion of the Debye type which shows a critical slowing-down has been observed. Comparison of the present microwave data with the submillimeter data by Volkov
et al. (JETP Lett.
41 (1985) 17) reveals coexistence of a soft relaxational mode and an insufficiently softened optical phonon mode at all temperatures. It is concluded based on the present analysis that the phase transition should be driven by the soft relaxational mode.
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Noritaka Kuroda, Motoki Ito, Yuichiro Nishina, Masahiro Yamashita
1993 年 62 巻 7 号 p.
2237-2240
発行日: 1993/07/15
公開日: 2007/05/29
ジャーナル
認証あり
The near-infrared absorption spectrum has been measured in [Pt(en)
2][Pt(en)
2Cl
2](ClO
4)
4, (en)=ethylenediamine, irradiated with the 488 nm beam of an Ar-ion laser. In addition to the well-established intragap bands A around 1.6 eV and B around 2.0 eV, a broad band B′ is found to overlap the B band and be spread beyond 2.3 eV. No bands can be found at photon energies down to 1.2 eV below the A band. The results are discussed in relation to the “two-band” theory for polarons and solitons by Tinka-Gammel and coworkers (Phys. Rev. B
45 (1992) 6435).
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Yasuo Hashizume
1993 年 62 巻 7 号 p.
2241-2247
発行日: 1993/07/15
公開日: 2007/06/01
ジャーナル
認証あり
The motion of dislocations in the periodic Peierls potential is analyzed on the basis of kink-antikink solution of the sine-Gordon equation. It is assumed that the movement of the dislocation climbing the potential peak occurs by bending of a part of the dislocation line toward the potential ridge, formation of double kinks and their propagation to the opposite directions along the dislocation line. Small effects of external stress, friction and random force for the moving dislocation line are calculated by using soliton perturbation theories directly based on the inverse scattering transform.
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Masahiro Shiroishi, Taro Nagao, Miki Wadati
1993 年 62 巻 7 号 p.
2248-2259
発行日: 1993/07/15
公開日: 2007/06/01
ジャーナル
認証あり
A formalism of nearest-neighbor spacing distribution is presented for the random matrix ensembles related to general orthogonal polynomials. We show that the spacing distributions are derived from certain integral equations written in terms of the corresponding orthogonal or skew orthogonal polynomials. By using the formalism the universality of the spacing distribution is proved in special cases related to classical orthogonal polynomials.
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Masahiro Nakagawa
1993 年 62 巻 7 号 p.
2260-2269
発行日: 1993/07/15
公開日: 2007/06/01
ジャーナル
認証あり
A simple microscopic model of the antiferroelectric SmC
A* liquid crystals is proposed so as to analyse a few possible phase transitions between smectic subphases with various macroscopic dipole moments. It is theoretically implied that SmC
A* liquid crystals show a universal phase sequence SmC
A* (Antiferroelectric), SmCγ
* (Ferrielectric), and SmC
* (Ferroelectric) with increasing temperature in general. This is considered as a consequence of a competition between an attractive dipolar interaction and an excluded volume effect which results in a packing entropy related to the steric hindrance between the biaxial molecules. Also the effect of an external electric field on the phase transition is investigated.
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Norio Kawakami
1993 年 62 巻 7 号 p.
2270-2274
発行日: 1993/07/15
公開日: 2007/06/01
ジャーナル
認証あり
The asymptotic Bethe-ansatz (ABA) solution is obtained for the one-dimensional SU(
N) Calogero-Sutherland model and the SU(
N)
t-
J model with 1⁄
x2 long-range interaction. Bulk quantities and correlation exponents are computed. The results reproduce those obtained by Ha and Haldane using the exact Jastrow-type eigenfunctions. The ABA solution enables a simple and systematic treatment of the energy spectrum of the above models.
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Shokichi Kanno, Kei-ichi Tainaka
1993 年 62 巻 7 号 p.
2275-2278
発行日: 1993/07/15
公開日: 2007/06/01
ジャーナル
認証あり
The diffusion-limited reaction proposed by Anacker and Kopelman is investigated by means of correlation functions. This system is self-organized at a stationary state irrespective of initial conditions. In the present article we theoretically find the power-law spectra for the fluctuation of reactant densities: the power spectrum in
d-dimensional system is proportional to
f−1 (
f=frequency) for
d=2 and
f−3⁄2 for
d=1. Computer simulations comfirm the result for
d=1. On the other hand, in the case of
d=2, good agreement between theoretical and numerical results is not yet obtained.
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Noriyuki Kurita, Kinya Kobayashi, Hiroki Kumahora, Kazutami Tago, Kuni ...
1993 年 62 巻 7 号 p.
2279-2284
発行日: 1993/07/15
公開日: 2007/05/29
ジャーナル
認証あり
Using a molecular orbital method with non-local-density and Harris-functional approximations, the bond lengths, binding energies and HOMO-LUMO energy gaps of the carbon fullerenes C
n have been calculated on the assumption that all bond lengths in each fullerene are the same. The results are as follows. (1) The binding energies (per atom) of C
n containing hexagonal and pentagonal rings are expressed as F–A/
n, where F and A are the binding energy (per atom) of an infinitely long carbon fullerene and the excess strain energy of pentagonal rings, respectively. (2) The values of A for C
n (
n=24–36) are larger than those for C
n (
n=60–120), because of the adjoining pentagonal rings in the former. (3) C
60, C
70, C
100, C
90, C
32 and C
120, in decreasing order, have especially large HOMO-LUMO energy gaps and are expected to be less reactive.
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Makoto Okamura
1993 年 62 巻 7 号 p.
2285-2292
発行日: 1993/07/15
公開日: 2007/06/01
ジャーナル
認証あり
In this paper a theoretical study of shock pressures due to wave impact is presented. We obtain analytically impulsive pressure on a vertical plane wall in an infinite depth. The basic model we adopt here is presented by Cooker and Peregrine. We obtain two types of pressure impulse distribution on a wall by solving the model equation. These two types correspond to wave impact phenomena with and without a space trapped between the overturning wave face and the wall.
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Yuji Hattori
1993 年 62 巻 7 号 p.
2293-2305
発行日: 1993/07/15
公開日: 2007/06/01
ジャーナル
認証あり
Statistical equilibrium of two finite-mode systems closely related with two-dimensional ideal flow have been studied extensively. The two systems are an ordinary inviscid truncated system (ITS) and Zeitlin’s finite-mode analogue (ZFA). The remarkable feature of ZFA is that it has higher-order invariants which are phase dependent. An analytical study suggests that the constraint by these invariants has little effect on the energy spectrum. This is confirmed by extensive numerical calculations. Definite evidence of ergodicity in ITS has been also obtained numerically.
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Osamu Sano, Hiromi Takano-Ohmuro
1993 年 62 巻 7 号 p.
2306-2313
発行日: 1993/07/15
公開日: 2007/05/29
ジャーナル
認証あり
Hydrodynamical calculation of the drag and side forces on a single myosin molecule in an incompressible viscous fluid, which is placed in an otherwise uniform flow along its rod direction, is made on the basis of the Stokes equation. The beads model approximation is employed to describe various conformation of the heads and tail of this macromolecule. The results are compared with an electrophoretic measurement of an
intact myosin of the smooth muscle in a pyrophosphate polyacrylamide gel. Biochemical analysis is combined to give the relation between the phosphorylation of the myosin regulatory light chains and the orientations of the two heads relative to the rod axis. Possible actin-and-myosin interaction mechanisms which may cause the smooth muscle contraction are discussed.
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Nobuo Yoshiyasu, Ken Adachi, Ryuji Takaki
1993 年 62 巻 7 号 p.
2314-2323
発行日: 1993/07/15
公開日: 2007/06/01
ジャーナル
認証あり
Self-induced vibration of a drop of liquid N
2 placed on a horizontal plate was observed, where the temperature
Ta of the plate and the surrounding gas was kept constant at a value within −100°C∼200°C. The drop showed several modes of vibration with polygonal shapes in plane view and made transitions to other modes as its size decreased through boiling. It was found that the process of mode selection did not depend on
Ta, if it was within −100°C∼150°C. Above 150°C, the drop selected modes rather randomly. Vibrational frequency was measured. It agreed with theory, but showed a small deviation for
Ta<−69°C. A theoretical estimation of the temperature of boiling liquid surface is made to explain this deviation, and its result is discussed. An aspect of dynamical pattern formation is suggested in relation to the degree of thermal inequilibrium.
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Masayuki Oikawa
1993 年 62 巻 7 号 p.
2324-2333
発行日: 1993/07/15
公開日: 2007/06/01
ジャーナル
認証あり
A modified nonlinear Schrödinger equation (MNLS) which is obtained by adding a third-order dispersion term to the nonlinear Schrödinger equation (NLS) is investigated numerically under the periodic boundary condition. It is found that the third-order dispersion term can give rise to chaotic behaviour. It is also found that when the coefficient of the third-order dispersion term becomes small the solutions of the MNLS equation come to have resemblance in the overall aspect to those of the NLS equation.
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Hyoung Suk Kim, Sang June Hahn, Jae Koo Lee
1993 年 62 巻 7 号 p.
2334-2350
発行日: 1993/07/15
公開日: 2007/05/29
ジャーナル
認証あり
We have investigated the possibility of tunable Infrared Free-Electron Laser with Test Linac of Pohang Accelerator Laboratory through one dimensional simulation which includes energy spread and space charge effects and 3-D particle simulation that ignores space charge force but takes into account the energy spread and the emittance of the electron beam and the diffraction of the electromagnetic wave. The enhanced current density of the Test Linac makes it feasible to amplify the 4.2 kW signal of 10.6 μm radiation to 200 MW level. Extending the design parameters, electron beam energy (20∼60 MeV), wiggler field strength (around 3 kG), and radiation wavelength (10∼90 μm), we have revealed the requisites for the design of the tunable radiation source and the expected gains in that frequency range. It is shown to generate more than 100 MW in the tunable range.
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Takayasu Tanaka
1993 年 62 巻 7 号 p.
2351-2358
発行日: 1993/07/15
公開日: 2007/06/01
ジャーナル
認証あり
A new mechanism is presented of an excitation of a high frequency wave by a low frequency wave in a plasma. This mechanism works when the low frequency wave varies in time in a manner deviated from a usual periodic motion with a constant amplitude.
The conversion rate is usually not large but the conversion is done without time delay after the variation of the low frequency wave. The Manley Rowe relation in the usual sense does not hold in this mechanism. This mechanism can excite also waves with same or lower frequencies.
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S. Pesi\'{c}, A. Stoji\'{c}
1993 年 62 巻 7 号 p.
2359-2367
発行日: 1993/07/15
公開日: 2007/06/01
ジャーナル
認証あり
The influence of thermal effects on the ray path near and through the electron cyclotron resonance (ECR) is investigated. First, the source of differences between the thermal plasma and cold plasma ray descriptions is identified. Ray paths obtained in (i) cold plasma, (ii) hot Maxwellian plasma and (iii) weakly relativistic Maxwellian plasma are then discussed. It is found that in the ECR region thermal effects may induce a substantial ray refraction, ray reflection and change of the wave polarization. This has important implications on the propagation and absorption characteristics of both, the low and the high field side launched electromagnetic waves.
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Akihide Takeda, Nobuaki Ikuta
1993 年 62 巻 7 号 p.
2368-2381
発行日: 1993/07/15
公開日: 2007/06/01
ジャーナル
認証あり
Due to large cross sections for vibrational excitation which sharply rise in the bottom region of the Ramsauer minimum, electrons in CF
4 in low reduced electric fields E/N show particular transport properties. The transport property and velocity distribution of electrons in CF
4 are analysed using the FTI method of the authors over a wide range of E/N from 0.1 to 50 Td. The mobility, drift velocity and the negative differential conductivity are discussed with the flight behavior of electrons regarding the variation of elastic and inelastic collision frequencies with energy.
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Yukiharu Ohsawa
1993 年 62 巻 7 号 p.
2382-2387
発行日: 1993/07/15
公開日: 2007/05/29
ジャーナル
認証あり
A theoretical model for solar energetic particles is presented, which consistently describes the basic composition pattern of heavy ions,
3He-enrichments, and rapid ion acceleration to relativistic energies. On the basis of the theory of particle acceleration by nonlinear magnetosonic waves, which can explain the prompt ion acceleration, we obtain the fraction of high-energy ions as a function of the ion mass. Then, noting that random fluctuation velocities of heavy ions due to magnetohydrodynamic turbulence can easily exceed their thermal speeds, we show that the relative abundances of ions accelerated by magnetosonic waves in magnetohydrodynamic turbulence become similar to those of the background plasma. The theory is further applied to the acceleration of
3He particles in the presence of turbulent waves with frequencies near the
3He cyclotron frequency, and it is found that huge enrichments of
3He particles are possible.
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Satoshi Kanai, Yoshimi Tsuchiya
1993 年 62 巻 7 号 p.
2388-2394
発行日: 1993/07/15
公開日: 2007/06/01
ジャーナル
認証あり
Sound velocity has been measured in the liquid Bismuth-Zinc system as a function of temperature and composition to investigate the propagation of ultrasonic waves in a metallic liquid alloy with a miscibility gap. The critical point determined from the dependence on temperature of the sound velocity is 580±3°C at 17.8±0.3 at.% Bi. Above the critical point, the sound velocity shows a temperature dependence associated with critical concentration fluctuations.
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Ikuo Yamamoto, Shunsuke Hirotsu
1993 年 62 巻 7 号 p.
2395-2401
発行日: 1993/07/15
公開日: 2007/06/01
ジャーナル
認証あり
Ultrasonic wave velocities of perovskite-type crystal CsPbCl
3 have been measured above the cubic-tetragonal phase transition temperature under hydrostatic pressure. The combinations of third-order elastic constants
C111+2
C112,
C111−
C123 and
C144+2
C166 were deduced from pressure derivatives of the sound velocity over the temperature interval 47–100°C. Critical anomalies were found in the temperature dependence of
C111+2
C112 and
C111−
C123. It is shown that the order-parameter fluctuation is responsible for the observed anomaly in the third-order elastic constants.
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Chikara Sugiura
1993 年 62 巻 7 号 p.
2402-2407
発行日: 1993/07/15
公開日: 2007/05/29
ジャーナル
認証あり
With a two-crystal vacuum spectrometer, the Rh
Lβ
2,15 emission spectrum in fluorescence from (NH
4)
3RhCl
6 has been measured together with that from rhodium metal. The metal spectrum consists of a single broad band, while the (NH
4)
3RhCl
6 spectrum is composed of a prominent peak and its low-energy shoulder. The measured
Lβ
2,15 emission spectrum of Rh metal is compared with available X-ray photoelectron valence-band spectra and theoretical X-ray
Lβ
2,15 emission spectra. It is shown that there is good agreement between them. The Rh
Lβ
2,15 emission spectrum of (NH
4)
3RhCl
6 is presented along with the Rh
LIII absorption, Cl
Kβ emission and Cl
K absorption spectra of this compound, reported previously. These spectra are interpreted in terms of the molecular orbitals of octahedral complex [RhCl
6]
3−.
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Shigeki Gunji, Hiroshi Kamimura, Takashi Nakayama
1993 年 62 巻 7 号 p.
2408-2418
発行日: 1993/07/15
公開日: 2007/06/01
ジャーナル
認証あり
New types of intercalation compounds by intercalating lithium atoms into semiconducting α-rhombohedral boron are predicted theoretically, based on the
ab initio total-energy pseudopotential calculations in the local density approximation. A novel interesting feature of these new materials is to exhibit a possibility that both donor- and acceptor-type metallic compounds are obtained from the same species of intercalant atom, depending on the positions of an intercalant. It is shown by the total energy calculations that donor-type compound in which Li are intercalated into the center of a rhombohedral unit cell is the most stable.
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Norio Kawakami
1993 年 62 巻 7 号 p.
2419-2424
発行日: 1993/07/15
公開日: 2007/05/29
ジャーナル
認証あり
The long-distance critical behavior of correlation functions is studied for the multicomponent Jastrow wave function in one dimension (1D), which is a 1D analogue of generalized Laughlin’s wave function for the fractional quantum Hall effect. The critical exponents for various correlation functions are obtained analytically. We then impose the chiral constraint and discuss the relationship to the chiral Luttinger liquid for the edge states of the quantum Hall effect.
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B. Ünal, B. Alkan
1993 年 62 巻 7 号 p.
2425-2430
発行日: 1993/07/15
公開日: 2007/06/01
ジャーナル
認証あり
Mobility formula recently derived by us has been applied to liquid metals and alloys and detailed resistivity calculations has been carried out for Na metal. ρ versus
T curve goes almost parellel with the experimental one.
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L. Mihailov, M. Ivanovich, M. Georgiev
1993 年 62 巻 7 号 p.
2431-2444
発行日: 1993/07/15
公開日: 2007/06/01
ジャーナル
認証あり
TC-
x phase diagrams for La
2−xSr
xCuO
4 are derived from a model where in-plane holes dimerize to form bosons via the polarization-induced pairing aided by nearby apical oxygens O(A). O(A) are off-centered ‘a la Toyozawa’ by coupling to the
Eu bending mode of dual O(A)–Cu(P)–O(A) bonds which enhances their polarizability. Apex oxygens are also gates through which charge leaks from CuO
2 planes across Sr-containing La–O layers to effect the interlayer coupling. The latter is mainly controlled by coupling to the
A2u stretching mode of the dual bond. The Cu(P)–O(A) covalent bonding is doping-dependent. It modulates the electronic energies and thereby the axial charge leak. Dome-shaped
TC-
x diagrams result from the interplay between the increasing hole concentration and decreasing gate opening as
x grows. They compare well with experimental
TC-
x data reported for La
2−xSr
xCuO
4.
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Nobuaki Miyakawa, Yasushi Shiina, Tsutomu Kaneko, Nobuo Tsuda
1993 年 62 巻 7 号 p.
2445-2455
発行日: 1993/07/15
公開日: 2007/06/01
ジャーナル
認証あり
Following a short summary of our tunneling results for Bi
2Sr
2Ca
n−1Cu
nO
y (Bi22(
n−1)
n) (
n=1–3), the tunneling phonon structures of Bi2212 are analyzed according to the Eliashberg scheme assuming a certain normal-state conductivity. The McMillan-Rowell spectral function is similar to a model spectral function in which only the Cu–O vibrations are taken into account and the interaction strength is assumed to increase with decreasing frequency. To ascertain whether excitation other than that of phonons contributes to pair formation, we calculated the tunneling conductance for various composite spectral functions. As far as we could discover, the phonon-only spectral function is the function which best explains the tunneling results.
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Ikuo Nakai, Tomoki Fukagawa
1993 年 62 巻 7 号 p.
2456-2461
発行日: 1993/07/15
公開日: 2007/05/29
ジャーナル
認証あり
We have made precise measurements of the magnetization on an amorphous ferromagnet Gd
67Ni
33 below 300 K in fields up to 5.27 T. The magnetization obeys the simple spin wave
T3⁄2 law below about 90 K. The spin wave stiffness constant thus obtained is independent of magnetic fields and temperatures. The susceptibility follows the Curie-Weiss law above about 220 K. The amorphous Gd
67Ni
33 alloy is a typical example of Heisenberg ferromagnet such as amorphous Gd
68Cu
32 reported previously.
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Tosizumi Aoki
1993 年 62 巻 7 号 p.
2462-2469
発行日: 1993/07/15
公開日: 2007/06/01
ジャーナル
認証あり
The self-consistent spin-wave approach proposed in the previous paper is applied to the XY and Heisenberg antiferromagnets with
S=1⁄2 on a triangular lattice. Our approach is composed of two procedures. One is that the approximate boson representation of spin operators is derived from the equations of motion linearized about the equilibrium state on the assumption of the appearance of a long-range order (LRO). The other is that the following constraint is retained in the average: (
Sjy)
2+(
Sjz)
2=1⁄2 when the
x-axis is taken as the quantized one. Our estimates for the LRO and ground-state energy are in fairly good agreement with the results obtained by various methods. In contrast with the ordinary spin-wave theories, it is emphasized that the constraint becomes more effective in the systems with large spin fluctuations due to the zero-point motion.
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Hiroshi Ajiki, Tsuneya Ando
1993 年 62 巻 7 号 p.
2470-2480
発行日: 1993/07/15
公開日: 2007/06/01
ジャーナル
認証あり
Magnetic properties of carbon nanotubes (CN’s) are calculated in the effective-mass theory. The magnetic moment in a magnetic flux parallel to the tube axis oscillates as a function of the flux with period determined by the flux quantum and phase depending on whether CN is metallic or semiconducting. For a magnetic field perpendicular to the axis, CN’s exhibit a large diamagnetism independent of metallic or semiconducting. The magnetic moment induced by a perpendicular field is about three order of magnitude as large as that by a parallel field.
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Hitoshi Ohta, Seisaku Imagawa, Mitsuhiro Motokawa, Hironobu Ikeda
1993 年 62 巻 7 号 p.
2481-2489
発行日: 1993/07/15
公開日: 2007/05/29
ジャーナル
認証あり
The electron paramagnetic resonances of CsCo
xMg
1−xCl
3 (
x=0.2, 0.4 and 0.6) have been observed at 220, 370, 585, 693.6 and 762.2 GHz in pulsed magnetic fields from 4.2 to 50 K. Paired spin excitations of intrachain and interchain pairs have been observed. Both intrachain and interchain exchange interactions are determined and our results suggest that there are at least two kinds of interchain exchange interactions in this system. The detailed analysis and the comparison of exchange interactions with those obtained by other measurements for CsCoCl
3 are discussed.
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Satoshi Sasaki, Noboru Miura, Takehiko Yagi, Yoshiji Horikoshi
1993 年 62 巻 7 号 p.
2490-2500
発行日: 1993/07/15
公開日: 2007/06/01
ジャーナル
認証あり
We have observed type-I–type-II transition in photoluminescence spectra of GaAs/AlAs short period superlattices under pulsed high magnetic fields up to 150 T and hydrostatic pressures up to 30 kbar. In magneto-photoluminescence spectra, the luminescence intensity showed an abrupt decrease at some critical magnetic field due to a
Γ-
X crossover in the conduction band, and also a remarkable hysteresis when the pulsed fields were swept up and down. The hysteresis arises from the fast sweep of the field pulse in the similar time scale to the lifetime of the type-II exciton, as shown by a rate equation analysis based on a two-level model. The controversial electron effective mass of the AlAs
X-point was estimated as
mX=0.16±0.07
m0.
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Tae Hun Chung, Jae Koo Lee
1993 年 62 巻 7 号 p.
2501-2510
発行日: 1993/07/15
公開日: 2007/05/29
ジャーナル
認証あり
Numerical calculations are performed based on the one-dimensional model for a tapered FEL amplifier with the combined helical wiggler and axial guide magnetic field operating in Raman regime. The longitudinal electric field due to space charge bunching can be formulated either by solving the coupled Maxwell and linear fluid equations or by solving the coupled kinetic and longitudinal wave equations. Both formulations are incorporated into the numerical code and the simulation results are compared. The criterion for the consideration of the space change effect depends on the value of the electron beam parameter ξ(ξ
2=
e2nb⁄γ
0mc2kw2). Besides, the perspective parameter studies are performed.
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Kenji Miyakawa, Yoshihide Ito, Kozue Kaibara
1993 年 62 巻 7 号 p.
2511-2515
発行日: 1993/07/15
公開日: 2007/05/29
ジャーナル
認証あり
The coacervation process of elastomeric protein α-elastin in aqueous solutions was investigated as a function of temperature by using dynamic light scattering. Two kinds of dynamical behaviors were found, which were dependent on both the concentration and the scattering vector. Near the critical point, the diffusion coefficient, deduced from the relaxation time, showed a remarkable decrease. When far from the critical concentration, on the contrary, the diffusion coefficient showed a gradual increase on raising the temperature, followed by a rapid increase near the temperature at which the sample started to be turbid. The results agree with recent findings on the role of the critical fluctuations on the condensation of biostructural polymers leading to the supramolecular ordering.
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T. C. Chiam
1993 年 62 巻 7 号 p.
2516-2517
発行日: 1993/07/15
公開日: 2007/05/29
ジャーナル
認証あり
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Hideo Takeuchi, Hidekazu Tanaka, Masanori Arakawa
1993 年 62 巻 7 号 p.
2518-2519
発行日: 1993/07/15
公開日: 2007/06/01
ジャーナル
認証あり
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Katsuhide Ito, Hiroki Akane, Kikuo Ohi
1993 年 62 巻 7 号 p.
2520-2521
発行日: 1993/07/15
公開日: 2007/06/01
ジャーナル
認証あり
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Yoshiaki Uesu, Noriaki Horiuchi, Eisuke Osakabe, Satoshi Omori, Boris ...
1993 年 62 巻 7 号 p.
2522-2523
発行日: 1993/07/15
公開日: 2007/05/29
ジャーナル
認証あり
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Seiji Kojima, Shinichi Hamazaki, Masayuki Tsukioka, Masaaki Takashige
1993 年 62 巻 7 号 p.
2524
発行日: 1993/07/15
公開日: 2007/05/29
ジャーナル
認証あり