The electronic viewpoint on the morphology of the microclusters

A possible role of the electron interaction in the morphology of the microcluster is studied. Highly symmetrical configuration leads to highly degenerated single-particlelevels. They are preferable for the emergence of the magnetic polarization (the Hundtendency). On the other hand, the splitting of the degenerated Fermi level due to the lowering of the symmetry sometimes reduces the ground state energy (the Jahn-Teller tendency). The conflict of these two tendencies is investigated by a simple model.On leave from Department of Physics, Faculty of Science, Kyoto University, Kyoto, 606 Japan     

On representations of the canonical commutation relations

In the measure space construction of a representation of the canonical commutation relations, the strong continuity of any one parameter subgroup is proved.All multipliers for the separable case are expressed in a constructive manner and an irreducibility criterion for a subset of multipliers is obtained.Preprint No. 1970-27.On leave from Research Institute for Mathematical Sciences Kyoto University, Kyoto, Japan.     

Gibbs states of a one dimensional quantum lattice

A one dimensional infinite quantum spin lattice with a finite range interaction is studied. The Gibbs state in the infinite volume limit is shown to exist as a primary state of a UHF algebra. The expectation value of any local observables in the state as well as the mean free energy depend analytically on the potential, showing no phase transition. The Gibbs state is an extremal KMS state.On leave from Research Institute for Mathematical Sciences, Kyoto University Kyoto, Japan.     

An algebraic approach to the planar coloring problem

We point out a general relationship between the planar coloring problem withQ colors and the Temperley-Lieb algebra with parameter . This allows us to give a complete algebraic reformulation of the four color result, and to give algebraic interpretations of various other aspects of planar colorings.Work supported in part by NSF Grant #DMS-882602, the program for Mathematics and Molecular Biology, UC Berkeley, and a visiting fellowship of the Japan Society for the promotion of science at Kyoto University, Kyoto, JapanWork supported in part by DOE Contact #DE-AC02-76ERO3075 and by a Packard Fellowship for Science and Engineering     

Bayesian Estimation of Atmospherically Distorted Wavefronts Using Shack-Hartmann Sensors

We describe an optimal solution for the modal reconstruction of wavefronts distorted by Kolmogorov turbulence. The approach is Bayesian and calculates the maximum a posteriori (MAP) estimate for the Karhunen-Loeve expansion coefficients.Presented at the International Commission for Optics Topical Meeting, Kyoto, 1994.     

基体分离/MC-ICP-MS测定树皮表层235U/238U同位素比率

分别从日本广岛和京都采集了香樟树(Cinnamomum camphora)树皮样品共12份,用X射线能谱仪研究了树皮表层基体元素组成,并用扫描电镜观察了树皮表层微观形貌.将树皮表层样品进行干灰化法处理后,采用DOWEX(R)1-X8型阴离子交换树脂分离基体元素,然后用多接收器电感耦合等离子体质谱仪(MC-ICP-MS)测定了树皮表层235U/238U同位素比率.研究结果表明:树皮表层主要基体元素为Al,Ca,Fe,K,Mg,Si和C,O,S;采用不同浓度硝酸淋洗DOWEX(R) 1-X8型阴离子交换树脂可实现树皮表层痕量U与基体元素的有效分离.与京都树皮表层相比,广岛树皮表层不仅U含量显著偏高(P=0.012),而且部分样品235U/238U同位素比率亦略高于其自然丰度比.     

Real Time Object-Locating Method Using Convolution Image

A simple method using a convolution image to locate an object in a scene is described. The image is processed by an optical system using a spatial light modulator in real time. Experimental results are presented with discussion on the improvement in the system performance.Presented at the International Commission for Optics Topical Meeting, Kyoto, 1994.     

Quasifinite highest weight modules over the superW 1+∞algebra

We study quasifinite highest weight modules over the supersymmetric extension of theW ₁₊ algebra on the basis of the analysis by Kac and Radul. We find that the quasifiniteness of the modules is again characterized by polynomials, and obtain the differential equations for highest weights. The spectral flow, free field realization over the (B, C)-system, and the embedding into (|) are also presented.Address after April 1, 1994: Research Institute for Mathematical Sciences, Kyoto University, Kyoto 606, JapanAddress after April 1, 1994: Uji Research Center, Yukawa Institute for Theoretical Physics, Kyoto University, Uji 611, Japan     

Orientational disordering of the CH4Kr mixture induced by spin conversion at T < 1 K.

Measurements of the longitdinal relaxation time T_l in the solid CH₄Kr mixture at low temperatures indicate that the orientationally ordered structure with 33% Kr is modified to a disordered phase by nuclear spin conversion as predicted by the Kyoto group.     

Verification of terahertz-wave spectrophotometry by Compton backscattering of coherent synchrotron radiation

We developed a continuous-spectrum light beam from Compton backscattering by using coherent synchrotron radiation in an L-band linac at the Kyoto University Research Reactor Institute. The ratio of Compton backscattered photons to background photons when coherent synchrotron radiation was used was three times larger than when coherent transition radiation was used. The transmission spectrum of a polystyrene film in the terahertz-wave region was evaluated by measuring the spectrum of the Compton backscattered photons and it roughly agreed with that measured by a Martin–Puplett-type interferometer. The spectrophotometry using Compton backscattering shows promise as a new tool for investigations in terahertz-wave science.     

Lattice statistical aspects of electron correlation problems

A technique for the lattice statistics, the Kikuchi's cluster variation method, is applied to improve the Gutzwiller's method for the ground state problem of the many-electron system on the assumption that small number of macroscopic variables are enough to describe the feature of a whole configuration. The momentum distribution in the present approximation is no longer a step function consisting of two constant values, though some people might have been thinking that too simple distribution is an intrinsic weak point of the Gutzwiller's method. A metal-insulator transition of the Brinkman-Rice type takes place in the half-filled case also in the higher order approximations. The merit of the present scheme is in the realization of the correlated wavefunction rather than in the lowering of the ground state energy. Some spatial correlation functions are calculated. The role of the interaction range is studied.A part of this work was reported at the IUPAP International Conference on Statistical Physics held at Haifa, 24–30 August 1977On leave of absence from Department of Physics, Faculty of Science, Kyoto University, Kyoto 606, Japan     

Magnetic properties of rare-earth permanent magnets under a high radiation environment

An study on the demagnetization of rare-earth permanent magnets under high radiation environment is started from the microscopic point of view. The demagnetization of NEOMAX is successfully induced by the well defined neutron field produced by the 5 MW reactor in Kyoto University. Preliminary TDPAC measurement of ¹¹¹Cd(←¹¹¹In) in NEOMAX, including demagnetized one, is reported.     

Radius Measurement of a Concave Mirror by a Zone Plate Interferometer

A new technique to measure the radius of a concave mirror is proposed, in which the radius is calculated from the difference of the two interferograms obtained before and after shifting the sample perpendicular to or along the optical axis. By comparison of these two shifting directions, it is shown that since the amount of shift can be measured accurately and the result is insensitive to the tilt during the shifting, better accuracy can be obtained by shifting the sample along the optical axis.Presented at the International Commission of Optics Topical Meeting, Kyoto, 1994.     

The electronic viewpoint on the morphology of the microclusters

Although the five-fold symmetry conflicts with the crystalline long range order, it can appear in some finite systems. In order to search for such possibility in the microclusters in the small size limit and to clarify the roles of the electrons in the morphology, the electronic states are studied in the tight binding scheme. The single electron spectra coming from thes- andp-atomic orbitals are derived for three types of the 13-atom clusters; with the fcc-like configuration, the hcp-like and the icosahedral. If the transfer integral between two surface atoms is put equal to that between the central and a surface atom in the icosahedral case, this configuration has the lowest total electronic energy in many cases studied, but not always. The fact that a surface atom has larger number of neighbours in the icosahedral configuration is surely of great advantage. It, however, is not almighty in the quantum case.On leave from Department of Physics, Faculty of Science, Kyoto University, Kyoto 606, Japan. A part of this work was done there     

The Toda lattice field theory hierarchies and zero-curvature conditions in Kac-Moody algebras

The two-dimensional Toda lattice field theories possess an infinite number of local conserved quantities in involution. These can be used as hamiltonians to define a consistent simultaneous evolution in the infinite number of associated times. Our previous explicit construction of the corresponding zero-curvature gauge potentials is used to extend the zero curvature to the complete infinite-dimensional space defined by these times by means of the Yang-Baxter equations. This result is elevated to the full Kac-Moody algebra with central extension thereby providing a link with the work of the Kyoto school.     

Phase Modulation Capability of Thin Twisted Nematic Liquid Crystal Panels at Double-Pass Configurations

Spatial light modulators whose phase modulation capability (PMC) exceeds 2π are strongly desirable. A double-pass configuration was evaluated to enhance PMC of twisted nematic liquid crystal panels. Theoretical analysis using Jones calculus is given, and it is proved that phase modulation is exactly doubled when the panel is sandwiched by two polarizers. Experiments to measure the PMC were carried out and results coincide well with the theory.Presented at the International Commission of Optics Topical Meeting, Kyoto, 1994.     

The Analytical Evaluation of Projection Optical Lithography

We earlier proposed an analytical and prospective method for evaluating projection optical lithography. In this paper, we apply it to more complicated cases, such as optimizing transparency of a half tone phase-shifting mask and considering the resolution enhancement technique which uses both multiple exposure and non-linear resist. We also apply it to the evaluation of isolated line patterns using 1:2 line-and-space patterns.Presented at the International Commission for Optics Topical Meeting, Kyoto, 1994.     

Real-Time Reconfigurable Interconnections for Parallel Optical Processing

In this letter we describe the advantages of a dynamic optical interconnection system for parallel information processing applications. The system is based on a liquid crystal television which acts as a binary phase-only spatial light modulator. We describe example algorithms where reconfigurable interconnects would be useful and present results of several interconnection topologies which have been implemented.Presented at the International Commission for Optics Topical Meeting, Kyoto, 1994.     

Observational Results of Stellar Speckle Interferometric Spectroscopy

Stellar speckle spectroscopy is a speckle interferometric method enabling us to separate point by point spectra on a stellar object with a diffraction-limited spatial resolution of a telescope. We describe observational results obtained with our system for speckle spectroscopy. Data of two binary stars, of which separations are closer than seeing disc, were taken and processed by cross-correlation method. In each object, spectral images of two component stars around the Hα line (656.3 nm) were spatially resolved with nearly diffraction-limited resolution. The separated spectra of ADS940 reveal different spectral types of the component stars. These results demonstrate the ability of the speckle spectroscopic method.Presented at the International Commission of Optics Topical Meeting, Kyoto, 1994.     

Bistable Optically Writable Image Memory Using Optical Feedback

A novel, parallel aligned optically addressed liquid crystal spatial light modulator has been used to implement an optically writable image memory. The memory uses a two-beam interferometer with optical feedback which exhibits thresholding, hysteresis, and bistability. We discuss the characteristics of the system, and present the results of an experimental demonstration.Presented at the International Commission for Optics Topical Meeting, Kyoto, 1994.