Showing papers by "Kyoto University published in 1980"
TL;DR: In this article, the effect of the spin-orbit interaction on random potential scattering in two dimensions by the renormalization group method is studied. And the localization behaviors are classified in the three different types depending on the symmetry.
Abstract: Effect of the spin-orbit interaction is studied for the random potential scattering in two dimensions by the renormalization group method. It is shown that the localization behaviors are classified in the three different types depending on the symmetry. The recent observation of the negative magnetoresistance of MOSFET is discussed. In recent experiments on MOSFET by Kawaguchi et al.,u it was found that electrons confined in the MOS inversion layer exhibit the negative magnetoresist ance. This effect is closely related to the localization problem in a random potential. In two dimensions, the quantum inter ference is important and, if the impurity scattering is spin-independent, the con ductivity vanishes at zero temperature even when the scattering is very weak. 2>
2,192 citations
TL;DR: An overview of the theory of homogeneous turbulence is given in this paper, where concepts of quasi-normality of large-scale motions are explained and modified zero cumulant approximation is presented.
Abstract: Publisher Summary This chapter presents an overview of the theory of homogeneous turbulence. Homogeneous isotropic turbulence is an idealized concept of turbulence, assumed to be governed by a statistical law that is invariant under arbitrary translation (homogeneity), rotation, or reflection (isotropy) of the coordinate system. This is an idealization of real turbulent motions, which are observed in nature or produced in a laboratory, and generally have much more complicated structures. This idealization was first introduced by Taylor to the theory of turbulence and used to reduce the formidable complexity of the statistical expression of turbulence, and thus make the subject feasible for theoretical treatment. Turbulence combines the difficulty of a strongly nonlinear dynamical system with that of a nonconservative system. The presence of energy dissipation due to viscosity deprives turbulence of the opportunity of being in a thermal equilibrium state. In this chapter, concepts of quasi-normality of large-scale motions are explained. A brief discussion on zero cumulant approximation and modified zero cumulant approximation is presented. Turbulence of other dimensions is also explained.
1,290 citations
TL;DR: In this article, a set of color features, (R + G + B) 3, R − B, and (2G − R− B) 2, were derived by systematic experiments of region segmentation.
965 citations
TL;DR: In this paper, the structure of a gaseous envelope surrounding a protoplanet has been investigated in connection with the formation of the giant planets, and the most remarkable result is that a common relation between the core mass and the total mass holds irrespectively of the regions in the solar nebula.
Abstract: The structure of a gaseous envelope surrounding a protoplanet has been investigated in connection with the formation of the giant planets. Under the assumptions of spherical symmetry and hydrostatic equilibrium, the structure has been calculated for the regions of Jupiter, Saturn, Uranus and Neptune. Energy transfer in the envelope has been taken into account precisely. When the core mass increases beyond some critical value, the envelope cannot be in hydrostatic equilibrium and collapses onto the core. The most remarkable result is that a common relation between the core mass and the total mass holds irrespectively of the regions in the solar nebula. Therefore, at the collapse, the core mass becomes almost the same regardless of the regions in the nebula. This is consistent with the conclusion obtained from the theory of internal structure of the present giant planets. The grain opacity in the envelope should be about 1 cm2/g in order to explain the estimated core mass (about 10 Earth's mass) of the giant planets. This value of the grain opacity is larger than that expected before.
773 citations
TL;DR: In this article, it was shown that the transmitted light from a ring cavity containing a nonlinear dielectric medium undergoes transition from a stationary state to periodic and nonperiodic states, when the intensity of the incident light is increased.
Abstract: It is theoretically shown that the transmitted light from a ring cavity containing a nonlinear dielectric medium undergoes transition from a stationary state to periodic and nonperiodic states, when the intensity of the incident light is increased. The nonperiodic state is characterized by a chaotic variation of the light intensity and associated broadband noise in the power spectrum. The experimental possibility of observing such a transition is also discussed.
662 citations
TL;DR: It was found that the intracranial artery below middle age are significantly stiff, and have higher incremental elastic moduli and wall stresses compared with the extracranial arteries.
594 citations
TL;DR: In this article, it was shown that the 2-point (resp. 2n-point) function or the 1-particle reduced density matrix satisfies a non-linear differential equation of Painleve type.
535 citations
TL;DR: In this article, the fracture strain in one process differs from that in another in several types of metal working processes for pore-free materials and porous materials and a method of estimating material constants in these criteria is also given.
523 citations
TL;DR: In this article, the coloring reaction of the thiobarbituric acid test for hydroperoxides was completely inhibited by the addition of EDTA, and it was necessary to add a metal salt to the reaction mixture to complete the reaction and also to add an antioxidant to prevent autoxidation when unoxidized unsaturated fatty acids co-exist.
Abstract: The coloring reaction of the thiobarbituric acid test for hydroperoxides was completely inhibited by the addition of EDTA. Therefore, it was necessary to add a metal salt to the reaction mixture to complete the reaction and also to add an antioxidant to prevent autoxidation when unoxidized unsaturated fatty acids co-exist. The optimal pH of the reaction was found at 3.6 using glycine-hydrochloric acid buffer.
399 citations
398 citations
TL;DR: In this paper, an analytical and numerical analysis of the physical behavior of a collapsing bubble in a liquid has been made, taking into account the effects of compressibility of the liquid, non-equilibrium condensation of the vapour, heat conduction and the temperature discontinuity at the phase interface.
Abstract: Analytical and numerical analyses have been made of the physical behaviour of a collapsing bubble in a liquid. The mathematical formulation takes into account the effects of compressibility of the liquid, non-equilibrium condensation of the vapour, heat conduction and the temperature discontinuity at the phase interface. Numerical solutions for the collapse of the bubble are obtained beyond the time when the bubble reaches its minimum radius up to the stage when a pressure wave forms and propagates outward into the liquid. The numerical results indicate that evaporation and condensation strongly influence the dynamical behaviour of the bubble.In addition, the propagation of the stress wave, both in a solid and a liquid, due to the collapse of the bubble has been observed by means of the dynamic photoelasticity. It is clearly demonstrated that the stress wave in a photoelastic specimen is caused by impact of the pressure wave radiated from the bubble.
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31 Dec 1980TL;DR: A new system for the structural analysis of complex aerial photographs is presented, which has the ability of focussing its attention of the analysis on the limited local areas where objects are highly supposed to exist.
Abstract: A new system for the structural analysis of complex aerial photographs is presented. This system has the ability of focussing its attention of the analysis on the limited local areas where objects are highly supposed to exist. Several kinds of strong and typical features are extracted, and these primary features of objects are combined to extract rough areas of the objects. This focussing mechanism saves the total processing time and facilitates the detailed analysis. The recognition process of the system is Implemented according to the 'production system'. The knowledge sources in this system are object-detection subsystems which analyse their individually focussed local areas and recognize specific objects respectively. All the results of the analysis are written in the common blackboard, and the system finds out conflicts and recovers errors by backtracking to feature extractions and low level processings. This architecture enables us to organize smoothly the diverse knowledge required to describe the complex structure on the ground surface.
TL;DR: In this paper, the existence of site-dependent impurity levels caused by inequivalent sites in $4H, $6H, and $15R$ SiC has been verified from a study of configuration coordinate phonons.
Abstract: The existence of site-dependent impurity levels caused by inequivalent sites in $4H$, $6H$, and $15R$ SiC has been verified from a study of configuration coordinate phonons. From analyses of donor-acceptor pair and free-to-acceptor luminescence, two kinds of impurity levels of A1, Ga, and B acceptors and N donors substituted cubic-like and hexagonal-like sites are determined. All the impurities in cubic-like sites take deeper levels than those in hexagonal-like sites. Ratios of the ionization energies are approximately constant independent of polytypes and the kind of impurities, 1.0-1.08 for acceptors and 1.55-1.88 for donors, in spite of a wide range of the ionization energies. The origin of the site effect on the impurity level is explained by assuming the existence of a local dielectric constant and a local effective mass. Haynes' rule is found to apply relatively well to N donors in different sites in various polytypes SiC.
TL;DR: For the spherically symmetric system, this paper proved the existence of a new locally finite flux which can be interpreted to represent the total energy flux of matter and gravitational field, and studied the relation between the behavior of the event horizon and the energy flux across it.
Abstract: For the spherically symmetric system, we prove the existence o{ a new locally cotEen·ecl flux which can be interpreted to represent the total energy flux of matter and gravitational field. ·with the aid of this conservation law, we study the relation between the behavior of the event horizon and the energy flux across it and look for constraints imposed on the total energy radiated to infinity. Some implications of the results of this study to the backreaction problem in the black hole evaporation are discussed.
TL;DR: In this article, two types of proteinaceous particles were observed under the electron microscope in the starchy endosperm of rice seeds, one was spherical with lamellar structure (PB-I), while the other was stained homogeneously by osmium tetroxide and not lamlar structured (PBII).
Abstract: Two types of proteinaceous particles were observed under the electron microscope in the starchy endosperm of rice seeds. One was spherical with lamellar structure (PB-I), while the other was stained homogeneously by osmium tetroxide and not lamellar structured (PB-II). Both types of proteinaceous particles were effectively condensed from the homogenate of developing rice endosperm by an aqueous polymer two-phase system using dextran-DEAE dextran-polyethylene glycol. Separation of both types was carried out by sucrose density gradient centrifugation. These proteinaceous particles were recovered at specific gravities of 1.27 and 1.29 for PB-I and PB-II, respectively. The protein composition of these particles and their solubility fractionation were examined. Prolamin appeared in the PB-I fraction, whereas PB-II was rich in glutelin and globulin.
TL;DR: Results on human sera correlate well with those obtained by the previously described enzymatic method and the chemical colorimetric method.
TL;DR: In this paper, it was pointed out that direct analysis of the crystal images may lead to an erroneous conclusion, because some of the periodicities in the image are due not to the structural periodicity but to some interferences between the scattered waves.
TL;DR: The HA ~~~~ei~ of influenza virus may f~~t~o~ as the F protein of HVJ does in certain conditions, causing hemolysis and cell fusion.
TL;DR: In this article, the use of integral equation methods in numerical calculations of exterior sound fields around scattering objects was investigated, where the objects investigated are a rigid body with edges and vertices, a rigid plate and an absorbing body.
TL;DR: In this article, the effect of cross-population pressure on the Volterra type dynamics for two competing species is investigated, and the effect has a tendency to enhance the stability assuring coexistence of species.
Abstract: The effect of cross-population pressure on the Volterra type dynamics for two competing species is investigated. On the basis of cross-diffusion induced instability, spatial segregation is studied. Spatially discrete models are also discussed. It is shown that this effect has a tendency to enhance the stability assuring coexistence of species. In continuous and discrete cases, time-dependent segregation processes are studied numerically.
TL;DR: The pygmy chimp’s society may be said to be integrated by the male/female affinity, little differentiated by sex in the grouping and the affinitive relations, and with high inter-individual tolerance and coherence.
Abstract: The affinitive interactions among the pygmy chimps seem to be the most frequent in the male/female combination, next in the female/female, and the least frequent in the male/male. The differences of frequencies among the combinations, however, are little, and it may be said that the pygmy chimps are not so much biased by sex in the affinitive relations. Their aggressive behavior is mild, and their behavior in general shows high tolerance, especially between different sexes and among females. Similar tendency is also seen in grouping (Kuroda, 1979). Therefore, the pygmy chimp’s society may be said to be integrated by the male/female affinity, little differentiated by sex in the grouping and the affinitive relations, and with high inter-individual tolerance and coherence.
TL;DR: In this article, the QCD corrections of order g−2 to the coefficient functions in polarized electroproduction were calculated for the flavour singlet part, where the Adler-Bell-Jackiw anomaly forces the relevant anomalous dimension to be nonzero.
TL;DR: In this article, the longitudinal profile of the lobate snout is satisfactorily analyzed by applying the theory of one-dimensional translation wave on an open channel, where the resistance coefficient is a function of concentration, depth, and grain diameter.
Abstract: Reviews on the yield strength and viscosity of the interstitial clay slurry in debris flow prove that ordinary debris flow may be modeled as a dilatant fluid in which the intergranular forces dominate. Theoretical velocity distributions in dilatant fluid compare well with the experimental results when the value of a numerical constant is appropriately selected. The longitudinal profile of the lobate snout is satisfactorily analyzed by applying the theory of one-dimensional translation wave on an open channel, where the resistance coefficient is a function of concentration, depth, and grain diameter. A remarkable segregation of particles, in which the larger ones move upwards, occurs in debris flow due to the effects of collisions of particles. The accumulation of boulders in the front part of debris flow is a result of the faster transportation of the larger particles in the upper layer of the flow than that of the smaller ones in the lower layer.
TL;DR: There are a number of reasons, although they are not absolutely convincing, as to why transdifferentiation can be a regulatory change not mainly due to a selective outgrowth of mutated cells or a small subpopulation of cells programmed toward only lens or pigment cells.
Abstract: Publisher Summary This chapter discusses the possible mechanisms of transdifferentiation or cellular metaplasia as a model for studying the programming of differentiation in neural and other cells at the cellular and molecular levels. Vertebrate eye tissues are characterized by a unique ability to perform extensive tissue metaplasia and to convert their specificities during regeneration in situ, after the removal of particular tissues. Studies on such instability in differentiation have now been extended to the cellular level by means of cell culture experiments. Besides the pigmented epithelial cells of the retina, cells from the neural retina (NR) of a number of vertebrate species can also extensively transdifferentiate into lens and pigment cells under conditions of cell culture. All the literature since 1975, when the phenomenon was first announced, has been reviewed in the chapter. Transdifferentiation in vitro is a sequential process starting from NR cells and terminating with lens cells, either through the differentiation of pigment cells or not. Several intrinsic and external factors affecting transdifferentiation have been described along with the molecular events observed in the process. There are a number of reasons, although they are not absolutely convincing, as to why transdifferentiation can be a regulatory change not mainly due to a selective outgrowth of mutated cells or a small subpopulation of cells programmed toward only lens or pigment cells.
TL;DR: A new one-step method for the light and electron microscopic localization of the ouabain-sensitive, K-dependent p-nitrophenylphosphatase (K-NPPase) activity of the Na-K-ATPase complex is introduced.
Abstract: A new one-step method for the light and electron microscopic localization of the ouabain-sensitive, K-dependent p-nitrophenylphosphatase (K-NPPase) activity of the Na-K-ATPase complex is introduced. The incubation medium contains p-nitrophenylphosphate (NPP) as substrate, lead citrate as the capture reagent, and dimethylsulfoxide (DMSO) as an activator. It is usable at the optimal pH of the K-NPPase, which is about pH 9.0 in the presence of 25% of DMSO. The effects of fixation, lead concentration, and DMSO on the enzyme activity were studied using rat kidney as a test tissue. The fixation of tissues in a mixture of 2% paraformaldehyde and 0.5% glutaraldehyde for 60 min at 0 degrees--4 degrees C preserved 45% of the enzyme activity. In the absence of DMSO, lead citrate (4.0 mM) caused 82% inhibition of the enzyme activity in fixed tissue. However, the addition of DMSO (25%) caused about 3-fold activation of the remaining activity. Cytochemical demonstration of the ouabain-sensitive K-NPPase activity was successfully made by this method at both light and electron microscopic levels.
TL;DR: In this article, a labeling procedure for the Origami world is proposed, which can find the 3D meaning of a given line drawing by assigning one of the labels, + (convex edge), − (concave edge), ←, and → (occluding boundary) to each line.
TL;DR: In this article, a single crystal of was grown by chemical vapor deposition using an system on a silicon substrate with a sputtered layer, and the grown layer of 4 μm thickness was confirmed as a one crystal by examination with reflection electron diffraction and x-ray diffraction.
Abstract: A single crystal of was grown by chemical vapor deposition using an system on a silicon substrate with a sputtered layer. The grown layer of 4 μm thickness was confirmed as a single crystal by examination with reflection electron diffraction and x‐ray diffraction. To reduce the large mismatch between and a silicon substrate, a sputtered layer was employed as a buffer layer. Even though the sputtered layer was polycrystalline, the subsequent layer deposited by CVD was a single crystal. The crystallinity of the deposited layer was strongly affected by the thickness of the sputtered layer, the substrate temperature during sputtering, and the temperature of chemical vapor deposition.